Shonka Research

 A ssociates

Draft Final Report of the 

Los Alamos 

 Historical Document 

Retrieval and Assessment 

(LAHDRA) Project 

Prepared for the Centers for Disease Control and Prevention (CDC) 

National Center for Environmental Health 

Division of Environmental Hazards and Health Effects 

Radiation Studies Branch 

June 2009 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT 
Shonka Research

 A ssociates

Draft Final Report of the 

Los Alamos Historical Document 

Retrieval and Assessment 

(LAHDRA) Project 

Prepared for the Centers for Disease Control and Prevention (CDC) 

National Center for Environmental Health 

Division of Environmental Hazards and Health Effects 

Radiation Studies Branch 

Prepared as a team effort by individuals from: 

ChemRisk, Inc., Shonka Research Associates, Inc., ENSR Corporation, 

NGTS, Inc., Advanced Technologies & Laboratories International, Inc., 

and several private consultants 

Project Director and Principal Author: 

Thomas Widner 

Contributing Authors: 

Joseph Shonka, Robert Burns, Susan Flack, Jack Buddenbaum, 

James O’Brien, Kate Robinson, Jeff Knutsen 

Other project team members: 

Cheryl Allen, Chris Atkinson, Lisa Barfield, Tim Bauer, Regan Burmeister, 

Joel Cehn, David Dodge, Ellen Donovan, Shannon Gaffney, Jou Hwang, Bill Joyce, 

Claudine Kasunic, Tim Kirkham, Jim Key, Chris Kirman, Matthew Le, 

Michael Marcial, William McCaughey, Tom Mongan, Duane Quayle, 

Cindy Saban, Debby Shonka, Michael Simmons, Jeff Vollmer, Jody Williams 

June 2009 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT

TABLE OF CONTENTS 

Executive Summary....................................................................................................................Front 

Chapter 1: Introduction to the LAHDRA Project................................................................. Tab 1 

Chapter 2: Overview of Historical Operations at Los Alamos............................................. Tab 2 

Chapter 3: Information Gathering at Los Alamos ................................................................ Tab 3 

Chapter 4: Plutonium Processing at Los Alamos ................................................................. Tab 4 

Chapter 5: Reactor Development and Operations at Los Alamos........................................ Tab 5 

Chapter 6: Accelerator Operations at Los Alamos............................................................... Tab 6 

Chapter 7: Tritium Processing at Los Alamos and a Screening Assessment 

 of Public Exposures ............................................................................................ Tab 7 

Chapter 8: Hot Cell Facilities and Operations at Los Alamos.............................................. Tab 8 

Chapter 9: Operations with Other Radionuclides................................................................. Tab 9 

Chapter 10: The Trinity Test ................................................................................................ Tab 10 

Chapter 11: Beryllium Use at Los Alamos........................................................................... Tab 11 

Chapter 12: Processing and Testing of High Explosives at Los Alamos ............................. Tab 12 

Chapter 13: The LANL Health Division .............................................................................. Tab 13 

Chapter 14: Environmental Monitoring at LANL................................................................ Tab 14 

Chapter 15: Development of Residential Areas Around Los Alamos.................................. Tab 15 

Chapter 16: Partial Chronology of Accidents, Incidents, and Events at LANL................... Tab 16 

Chapter 17: Prioritization of Radionuclide Releases............................................................ Tab 17 

Chapter 18: Screening-Level Evaluation of Airborne Plutonium Releases 

 from DP West Site ............................................................................................ Tab 18 

Chapter 19: Prioritization of Chemical Releases from LANL ............................................. Tab 19 

Chapter 20: Preliminary Screening of Airborne Beryllium Releases 

 from LANL Operations..................................................................................... Tab 20 

Chapter 21: Public Involvement within the LAHDRA Project............................................ Tab 21 

Chapter 22: Findings of the LAHDRA Project .................................................................... Tab 22 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT Page i 

LAHDRA PROJECT 

LIST OF ACRONYMS, INITIALISMS, AND ABBREVIATIONS 

25 Early code name for uranium-235; 

 (from the isotope’s atomic number (92) and atomic weight (235) 

28 Early code name for uranium-238; 

 (from the isotope’s atomic number (92) and atomic weight (238)

37 Early code name for neptunium-237 

 (from the isotope’s atomic number (93) and atomic weight (237) 

49 Early code name for plutonium-239 

 (from the isotope’s atomic number (94) and atomic weight (239) 

410 Early code name for plutonium-240 

 (from the isotope’s atomic number (94) and atomic weight (240); 

i.e., one higher than 239, hence the 10) 

ACIS Automated Chemical Inventory System 

ADWEM Associate Laboratory Directorate for Nuclear Weapons Engineering and 

 Manufacturing- formerly ALDNW 

AEC U.S. Atomic Energy Commission (DOE predecessor agency) 

AIRNET A LANL network of ambient air sampling stations 

AKA “also known as” 

ALDNW Former Office of Associate Laboratory Directorate for Nuclear Weapons 

ANP Aircraft Nuclear Propulsion 

ARF Atmospheric Release Fraction 

ATSDR Agency for Toxic Substances and Disease Registry 

BR Site Bruns Railhead Site (in Santa Fe, NM) 

BZ Breathing Zone 

CAS Chemical Abstracts Service, a registry for chemicals 

Case Early code word for curie, especially when referring to polonium shipments 

(“200 cases of Postum” meant 200 curies of polonium). 

CBD Chronic Beryllium Disease 

cc Cubic Centimeters 

CCNS Concerned Citizens for Nuclear Safety 

Cd Cadmium 

CDC Centers for Disease Control and Prevention 

CEARP Comprehensive Environmental Assessment and Response Program 

CEDE Committed Effective Dose Equivalent, a unit of radiation dose 

CFM Cubic Feet per Minute 

CFR Code of Federal Regulations 

Ci Curie, a unit of radioactivity; 1 Ci = 3.7 x 1010 disintegrations per second. 

CIC Former Computing, Information and Communications (CIC) Division, now the 

 Computing, Communications, and Networking Division (CCN). 

CM Chemistry and Metallurgy 

CMB Former Chemistry/Metallurgy/Baker Division, which later became MST 

 Division 

CMR Chemistry and Metallurgical Research 

CMR-12 The radiochemistry group at early LASL 

CO2 Carbon dioxide

DARHT Dual-Axis Radiographic Hydrodynamics Test 

D-Building Earliest plutonium processing facilities at Los Alamos 

DE Dose Equivalent, a unit of radiation dose 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT Page ii 

D&D Decontamination and Decommissioning 

DF Site Detonator Firing Site 

DOE U.S. Department of Energy 

DOEAL Department of Energy Albuquerque Operations Office 

DOP diocthyl phthalate, an aerosol often used to test effluent treatment filters 

DP DP Site1

, or TA-21. The site of plutonium processing at LANL from 1945 until 

 1978. Was also the site of polonium processing. 

DPM Disintegrations Per Minute, a rate of radioactive decay 

DSF Document Summary Form 

DU Depleted Uranium 

DVD Digital Versatile Disc 

DX Dynamic Experiments Division at LANL 

EEOICPA Energy Employees Occupational Illness Compensation Program Act 

EIS Environmental Impact Statement 

EMAD Engine Maintenance and Disassembly building at NRDS. 

EMF ElectroMagnetic Field 

EML Environmental Measurements Laboratory 

ENSR ENSR Corporation, a provider of ENvironmental SeRvices 

ER Environmental Restoration 

ERDA Energy Research and Development Administration (DOE predecessor agency) 

ERSS Environment and Remediation Support Services 

ESA Engineering Science and Application 

ES&H Environment, Safety, and Health 

eV Electron Volts 

FACA Federal Advisory Committee Act 

fCi Femtocurie, 10-15 curie, or 0.000000000000001 Ci 

FGI Foreign Government Information 

FQ Filter Queens- vacuum cleaners adapted at LASL to collect air samples 

G-2 Army Intelligence 

G/MAP Gaseous Mixed Activation Products, 

GMX GMX Division (possibly for Gadgets, Munitions, and Explosives) 

GMX-1 The Radiography Group at early LANL 

GPS Global Positioning System 

GT Site Anchor Site West 

H H Division or Health Division at LANL 

HAI History Associates Inc. 

H-Division The Health Division at LANL 

HE High Explosive 

HEPA High Efficiency Particulate Air filter 

HHS Dept of Health and Human Services 

HMX High Melting Explosive 

HP Site Hot Point Site 

HSE Health, Safety, and Environment 

HSR Health, Safety, and Radiation Protection group at LANL, formerly ESH 

HT Heat Treatment Building at TA-1 

HTML Hyper Text Markup Language 

HTO Tritiated water, water in which a hydrogen atom is replaced with tritium, 3

H 

 

1

 There are several theories about the origin of the “DP Site” name for TA-21. It may stand for D-Prime, since it 

replaced D Building, “D Plant,” “Displaced Persons,” “D-Plutonium,” or “D-Production” (Martin 1998). 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT Page iii 

HSPT Human Studies Project Team 

HYPO Water Boiler Reactor in its high-power configuration 

IAEA International Atomic Energy Agency 

ICRP International Commission on Radiological Protection 

ICRU International Commission on Radiation Units and Measurements 

IH Industrial Hygiene 

IM-5 The Records Management Group within the LANL Information Management 

 Division 

INEEL Idaho National Engineering and Environmental Laboratory 

IP Internet Protocol 

IPM Images per minute 

JHSPH Johns Hopkins School of Public Health 

kW kilowatt, one thousand watts of power 

LA– A prefix in many Los Alamos technical report designators 

LAHDRA Los Alamos Historical Document Retrieval and Assessment project 

LALP A type of LANL publication, from Los Alamos Laboratory publication 

LAMS A type of Los Alamos technical report, from Los Alamos Manuscript 

LAMPF Los Alamos Meson Physics Facility 

LAMPRE Los Alamos Molten Plutonium Reactor Experiment 

LANL Los Alamos National Laboratory (January 1981 to present) 

LANSCE Los Alamos Neutron Science Center- formerly LAMPF 

LA-PR A type of Los Alamos technical report, from Los Alamos Progress Report 

LAPRE Los Alamos Power Reactor Experiment 

LAPRE I First Los Alamos Power Reactor Experiment 

LAPRE II Second Los Alamos Power Reactor Experiment 

LASL Los Alamos Scientific Laboratory (January 1947 to December 1980; name 

 changed to Los Alamos National Laboratory in January 1981) 

LA- UR A type of Los Alamos technical report, from Los Alamos Unlimited Release 

LCLS LANL’s Legal Counsel Litigation Support Database 

LMFBR Liquid Metal Fast Breeder Reactor 

LOAEL Lowest Observed Adverse Effect Level 

LOPO Water Boiler Reactor in its low-power configuration 

LSSS Limiting Safety System Setting 

mA-hr Millampere-hours, a measure of work load for accelerators like at LANSCE 

MAP Mixed Activation Products 

MDL Minimum Detection Level 

MED Manhattan Engineer District 

MeV Million Electron Volts 

MFP Mixed Fission Products 

mL milliliter, one thousandth of a liter 

mm millimeter, one thousandth of a meter 

MDA Minimum Detectable Activity 

MOU Memorandum of Understanding 

MPC Maximum Permissible Concentration 

MST Materials Science and Technology Division 

MTR Materials Test Reactor 

MW Megawatt, one million watts of power 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT Page iv 

NASA National Aeronautics and Space Administration 

NBS National Bureau of Standards (predecessor to NIST) 

NCEH National Center for Environmental Health, part of CDC 

NCRP National Council on Radiation Protection and Measurements 

NEPA Nuclear Energy for the Propulsion of Aircraft (a USAF project) 

NERVA Nuclear Engine for Rocket Vehicle Application 

NESHAPS National Emissions Standards for Hazardous Air Pollutants 

NIOSH National Institute for Occupational Safety and Health 

NMED New Mexico Environmental Department 

NMT Nuclear Materials Technology 

NOAEL No Observed Adverse Effect level 

NOx Oxides of nitrogen 

NRC U.S. Nuclear Regulatory Commission 

NRDS Nuclear Rocket Development Station (at NTS) 

NSA Nuclear Science Abstracts 

NTK Need-to-know 

NTS Nevada Test Site 

OCR Optical Character Recognition 

ORNL Oak Ridge National Laboratory 

ORF Overall Release Fraction 

ORR Oak Ridge Reservation 

OSHA Occupational Safety and Health Administration 

OSR Off-Site Releases Database 

OSTI Office of Scientific and Technical Information 

OUO Official Use Only 

OWR Omega West Reactor 

OWREX Omega West Reactor Experiment 

PARKA A Phoebus 1 reactor set up as a critical assembly 

PBX Plastic Bonded Explosive 

PCB Polychlorinated Biphenyls 

PDF Portable Document Format 

PEL Permissible Exposure Limit 

PETN pentaerythritol tetranitrate, an explosive 

PHERMEX Pulsed High-Energy Radiation Machine Emitting X-rays 

PI Priority Index 

Postum Early code word for polonium, a material used at Los Alamos. 

PPM Pages Per Minute 

PROJECTS

Project Apple Rocky Flats Plant 

Project Camel The first full-scale test firing of the "Fat Man" type bomb (minus 

the plutonium) at the China Lake Naval Ordnance Sta. in CA. 

Project Orange Pantex Plant 

Project Royal unknown

Project Sugar Burlington Army Ordnance Plant in Iowa 

Project Tee unknown

PRG Preliminary Remediation Goals 

PRS Potential Release Sites 

PSR Proton Storage Ring 

P/VAP Particulate Various Activation Products 

Q The top level of security clearance granted by DOE 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT Page v 

R Roentgen, a unit of radiation exposure 

RAEHP Rio Arriba Environmental Health Partnership 

RaLa Radioactive Lanthanum 

RCRA Resource Conservation and Recovery Act 

RDX Rapid detonating explosive 

rem A unit of radiation dose equivalent, from Roentgen Equivalent Man 

RF Respirable Fraction 

RfC Reference Concentration 

RFETS Rocky Flats Environmental Technology Site 

RFI RCRA Facility Investigation 

RMAD Reactor Maintenance, Assembly, and Disassembly building at NRDS. 

RMC Records Management Center 

RPF Records Processing Facility 

RRES Risk Reduction and Environmental Stewardship 

RSAC Radiological Safety Analysis Computer program 

RSB CDC’s Radiation Studies Branch 

S Site TA-16; S is from Sawmill Site, after a former sawmill in the area. 

S-7 LANL’s Classification Office 

SAP Special Access Program 

SCI Sensitive Compartmented Information 

SED Special Engineering Detachment, in the Manhattan District era 

SL-1 A 3-MW experimental reactor in Idaho, Stationary Low-Power Plant No. 1, 

that was destroyed in 1961 when a control rod was removed manually. 

SM South Mesa 

SNM Special Nuclear Material 

SNPO Space Nuclear Propulsion Office, a joint office between the AEC and NASA. 

Soda Pulp Early code name for bismuth, which was irradiated to make polonium. 

SRA Shonka Research Associates, Inc. 

SRS Savannah River Site 

SUPO Water Boiler Reactor in its highest (Super) power configuration 

SWMU Solid Waste Management Unit 

TA Technical Area; a section of land at Los Alamos, with TA number from 0 to 74, 

that has been the site of identified operations or activities 

TATB 1,3,5-triamino-2,4,6-trinitrobenzene, an explosive 

TD Site Trap Door Site 

TFF Target Fabrication Facility 

TLD ThermoLuminescent Dosimeter 

TNT Trinitrotoluene, an explosive 

TR Transfer Record 

TR Trinity Project 

TRU Transuranic, that is elements having atomic numbers greater than 92 

TSTA Tritium Systems Test Assembly 

TU Tuballoy, an early code name for depleted uranium (from the British Tube 

 Alloys project, a code name for their atomic bomb program) 

UC University of California, operator of the Los Alamos facility since its founding 

UCNI Unclassified Controlled Nuclear Information 

UHTREX Ultra High-Temperature Reactor Experiment 

UK United Kingdom 

UNM University of New Mexico 

USAEC United States Atomic Energy Commission 

USEPA United States Environmental Protection Agency 

USGS United States Geological Survey 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT Page vi 

VHS Video Home System, a video cassette format patented by JVC 

Vitamin B Early code name for the isotope boron-10, a material used at Los Alamos. 

VJ Day The day of Allied victory over Japan in WW II 

VRS Virtual ReScan technology 

VTR Vault Type Room 

W Site W, the Hanford Plant near Richland, Washington 

W-47 Code designation for Wendover Air Base in Utah that was the training site of 

the 509th Composite Group, which dropped the atomic bombs over Japan. 

WB whole body 

WEM Weapons Engineering and Manufacturing 

WETF Weapons Engineering Tritium Facility (at TA-16) 

WFO Work for Others 

WIPP Waste Isolation Pilot Plant 

WNR Weapons Neutron Research Facility 

WP Weapons Physics 

WX Weapons Group WX 

X-10 The X-10 Site in Oak Ridge, Tennessee; now Oak Ridge National Laboratory 

Y Site Y, the code name for Los Alamos Laboratory under the MED from April 

 1943 to December 1946. 

Z Z Division (named for Jerrold R. Zacharias, a physicist from MIT’s Radiation 

Laboratory), an ordnance design, testing, and assembly group formed at LASL 

in July of 1945. Moved to the old Oxnard Air Field, east of Kirtland Air Base, 

just outside of Albuquerque between fall of 1945 and January of 1947 and 

became informally known as Sandia Base. 

_______________ 

Reference: 

Martin 1998. Martin, C. Los Alamos Place Names. Los Alamos Historical Society, Los Alamos, New 

Mexico. 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT Page vii 

Metric (SI) Prefixes 

Factor Prefix Symbol Factor Prefix Symbol 

1018 exa E 10-1 Deci d 

1015 peta P 10-2 Centi c 

1012 tera T 10-3 Milli m 

109 giga G 10-6 Micro μ 

106 mega M 10-9 Nano n 

103 kilo k 10-12 Pico p 

102 hecto h 10-15 Femto f 

101 deka da 10-18 Atto a 

Summary of New and Old Radiological Units 

Quantity Name Symbol In other units 

radioactivity becquerel Bq 1 disintegrations per second (dps) 

 (old) curie Ci 3.7 x 1010 Bq 

absorbed dose gray Gy joule/kilogram (J/kg) 

 (old) rad rad 10-2 Gy 

dose equivalent sievert Sv J/kg 

(old) rem rem 10-2 Sv

exposure coulomb per 

kilogram C/kg 

(old) roentgen R 2.58 x 10-4 C/kg 

 

Chemical Concentrations 

1.0 mg/L = 0.001 g/L = 1,000 μg/L = 1,000,000 ng/L 

1.0 μg/L = 0.001 mg/L = 1,000 ng/L 

1.0 ng/L = 0.001 μg/L = 0.000001 mg/L 

1.0 percent = 1.0 g/100g = 10 o

/oo (parts per thousand) = 10 g/kg = 10,000 mg/kg 

1.0 g/kg = 0.10 percent = 1,000 mg/kg 

1.0 mg/kg = 0.0010 g/kg = 0.00010 percent = 1,000 μg/kg 

1.0 μg/kg = 0.001 mg/kg = 1,000 ng/kg
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT Page viii 

Z #* Name Symbol

89 Actinium Ac 

13 Aluminum Al 

95 Americium Am 

51 Antimony Sb 

18 Argon Ar 

33 Arsenic As 

85 Astatine At 

56 Barium Ba 

97 Berkelium Bk 

4 Beryllium Be 

83 Bismuth Bi 

107 Bohrium Bh 

5 Boron B 

35 Bromine Br 

48 Cadmium Cd 

20 Calcium Ca 

98 Californium Cf 

6 Carbon C 

58 Cerium Ce 

55 Cesium Cs 

17 Chlorine Cl 

24 Chromium Cr 

27 Cobalt Co 

29 Copper Cu 

96 Curium Cm 

05 Dubnium Db 

66 Dysprosium Dy 

99 Einsteinium Es 

68 Erbium Er 

63 Europium Eu 

100 Fermium Fm 

9 Fluorine F 

87 Francium Fr 

64 Gadolinium Gd 

31 Gallium Ga 

32 Germanium Ge 

79 Gold Au 

72 Hafnium Hf 

108 Hassium Hs 

2 Helium He 

67 Holmium Ho 

1 Hydrogen H 

49 Indium In 

53 Iodine I 

77 Iridium Ir 

26 Iron Fe 

36 Krypton Kr 

57 Lanthanum La 

103 Lawrencium Lr 

82 Lead Pb 

3 Lithium Li 

71 Lutetium Lu 

12 Magnesium Mg 

25 Manganese Mn 

Z # Name Symbol

101 Mendelevium Md 

80 Mercury Hg 

42 Molybdenum Mo 

60 Neodymium Nd 

10 Neon Ne 

93 Neptunium Np 

28 Nickel Ni 

41 Niobium Nb 

7 Nitrogen N 

102 Nobelium No 

76 Osmium Os 

8 Oxygen O 

46 Palladium Pd 

15 Phosphorus P 

78 Platinum Pt 

94 Plutonium Pu 

84 Polonium Po 

19 Potassium K 

59 Praseodymium Pr 

61 Promethium Pm 

91 Protactinium Pa 

88 Radium Ra 

86 Radon Rn 

75 Rhenium Re 

45 Rhodium Rh 

37 Rubidium Rb 

44 Ruthenium Ru 

104 Rutherfordium Rf 

62 Samarium Sm 

21 Scandium Sc 

106 Seaborgium Sg 

34 Selenium Se 

14 Silicon Si 

47 Silver Ag 

11 Sodium Na 

38 Strontium Sr 

16 Sulfur S 

73 Tantalum Ta 

43 Technetium Tc 

52 Tellurium Te 

65 Terbium Tb 

81 Thallium Tl 

90 Thorium Th 

69 Thulium Tm 

50 Tin Sn 

22 Titanium Ti 

74 Tungsten W 

92 Uranium U 

23 Vanadium V 

54 Xenon Xe 

70 Ytterbium Yb 

39 Yttrium Y 

30 Zinc Zn 

40 Zirconium Zr 

 

 *The Z Number, or Atomic Number, of an element is the number of protons in its atomic nucleus. 

Table of the Elements
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary ES-1

Executive Summary 

The Los Alamos Historical Document Retrieval and Assessment (LAHDRA) project began in early 1999. 

It was conducted by the Centers for Disease Control and Prevention (CDC), with much of the work 

performed by contractors to CDC, namely ChemRisk Inc. and subcontractors Shonka Research 

Associates Inc., ENSR Corporation, Advanced Technologies and Laboratories International, Inc., and 

several individual consultants. The purpose of the LAHDRA project was to identify the information that 

is available concerning past releases of radionuclides and chemicals from the government complex at Los 

Alamos, New Mexico. “Project Y” was born as part of the Manhattan Project to create the first atomic 

weapons. LANL’s activities expanded after the war to include thermonuclear weapon design, high 

explosives development and testing, weapons safety, nuclear reactor research, waste disposal and 

incineration, chemistry, criticality experimentation, tritium handling, biophysics, and radiobiology. 

This report presents a summary of information that has been obtained by the LAHDRA team regarding: 

• historical operations at Los Alamos, 

• the materials that were used, 

• the materials that were likely released off site, 

• development of residential areas in Los Alamos, and 

• the relative importance of identified releases in terms of potential health risks. 

The information in this report was obtained from millions of records reviewed at Los Alamos by the 

project team, some books and reports that are publicly available, and interviews with past and current Los 

Alamos workers and members of the public. 

Products of the LAHDRA Project 

The products of the LAHDRA project include: 

• this report, which summarizes historical operation and prioritizes associated releases; 

• a project information database that contains bibliographic information and summaries of the content 

of relevant documents that were located by the project team; 

• sets of copies of the documents that were selected as relevant documents, made available in a reading 

room in Albuquerque; 

• a collection of electronic document images, as Portable Document Format (PDF) files, of all 

documents for which paper copies or electronic files were obtained; and 

• a chronology of incidents and off-normal events identified in review of reports prepared by Los 

Alamos’ Health Division. 

A Document Summary Form (DSF) was completed for each selected document (or set of related 

documents) to capture bibliographic data, project-specific information, and analyst comments. A 

Microsoft® Access database was created to describe and catalogue the information reviewed and collected 
ES- 2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary

during this project. There are currently 8,372 records in the LAHDRA database. A user-friendly frontend was developed for analysts to enter, review, and search the assembled information. As the number of 

paper copies grew and scanning technology matured, it was decided that a better way to preserve and 

present the reference material being collected by the LAHDRA team would be as scanned images. All 

documents were scanned, optical character recognition (OCR) processed, and saved as searchable PDF 

files of optimal quality. The collection of image files was indexed to support searching. In 2006, a new 

user interface and search engine based on X1 technology was put into place. This controlled-access, 

Internet based application called DocSleuth allows filtered, full text searching of bibliographic data for 

included documents and the text of associated image files. The included image files currently represent 

over 264,000 pages of historical documents. 

Systematic Document Reviews Conducted 

LAHDRA document analysts had unprecedented access for an independent study team reviewing 

historical records at LANL. A core group of approximately 15 analysts, most of whom held Q-level 

security clearances, worked on the project on a part-time basis. As originally specified, the LAHDRA 

project was divided into six phases that were planned to be completed sequentially. Each phase was 

meant to target a specific group of records, as outlined below: 

Phase 1: The LANL Records Management Center 

Phase 2: The LANL Archives 

Phase 3: The Technical Report Library 

Phase 4: Records at the Technical Areas 

Phase 5: Records pertaining to “Work for Others” 

Phase 6: Documents located at other sites 

Because of restrictions that were placed on the number of analysts that could work in a given repository at 

any time, the sequential approach was abandoned and work progressed in multiple repositories 

concurrently. The systematic document searches that were performed by the LAHDRA team are 

described in Chapter 3. The main elements of the information gathering process are summarized in Table 

ES-1 along with approximations of the quantities of documents reviewed at each repository. 

The initial and principal focus of the LAHDRA document review effort was the LANL Central Records 

Management Center. The LANL Records Center was a 15,000 square foot building located at 180 6th

Street in Los Alamos. The function of the Records Center is to receive and catalogue records from the 

various LANL groups and divisions, to place and maintain these records in retrievable storage, and 

disposition them in accordance with DOE retention and disposition guidelines and other associated 

requirements (such as the moratorium on destruction of records deemed pertinent to epidemiological 

studies). Late in the project, the Records Center was relocated to the new National Security Sciences 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary ES-3

Table ES-1. Summary of LAHDRA systematic document review efforts at Los Alamos

Location Approximate Quantities Reviewed 

Documents (or Groups 

of Documents) Selected 

and Summarized 

LANL Records Center 16,896 boxes of documents; 18,000 rolls of 

microfilm; 31,420 notebooks 

2,902 

LANL Reports 

Collection 

3,085 classified reports by LANL and 32,000 by 

others. 12,000 unclassified LANL reports in 

vault and 25,000 online. 90,000 unclassified 

reports by other plus 600,000 on microfiche 

1,529 

ES&H Records Center 

and satellites 

1,197 boxes of documents plus dosimetry and air 

quality records 

333 

LANL Archives 1,532 archived collections, with 125,000 folders 992 

Litigation Support 

Database 

75,724 documents by title; 3,813 full documents 347 

LANSCE Division 10,000 documents by title and 2,500 full 

documents in Admin. Building; 3,375 

documents in Radiological Air Monitoring 

Archive 

43 

WEM / WP Divisions 18,876 documents and 1,126 photos in vault; 36 

safes containing 7,056 documents 

2 

Engineering Drawings 

Center 

2,550 drawings on aperture cards plus ~1,000 reels 

of microfilm 

188 and 

~1,000 drawings 

Environmental 

Stewardship Division 

250,000 documents from the ERSS database, 137 

boxes of NEPA/EA records, 12 drawers of EIS 

documents, ~100 Cultural Resources reports 

1,056 

Industrial Hygiene & 

Safety Records 

8 lateral file drawers of historical records 17 

Former J Division 

(Field Testing) 699 boxes with approximately 11,000 folders 0 

Notes: Document review statistics current as of April 2009. ES&H = Environment, Safety, and Health; LANSCE = Los Alamos 

Neutron Science Center; WEM = Weapons Engineering and Manufacturing; WEP = Weapons Engineering and Physics; ERSS = 

Environment & Remediation Support Services; NEPA = National Environmental Policy Act; EA = Environmental Assessment; 

EIS = Environmental Impact Statement. 

Building (NSSB) at TA-3. Systematic review of the contents of the LANL Records Center that were 

accessioned prior to December 31, 1999 was completed in early June 2005, with all of the selected 

material received from LANL by the end of that month. During late 2008 into 2009, the project team 

reviewed records accessioned by the Records Center since 1999. 
ES- 4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary

During the first calendar quarter of 2005, LAHDRA analysts began reviewing printouts of LANL 

Archives collections and the folders that exist within each collection, identifying (based on review of 

folder titles) folders to be reviewed by the project team. The project team began the review of records at 

the LANL Archives in early June of 2005, and this review was completed in early May of 2006. During 

late 2008 into 2009, the project team reviewed collections added to the LANL Archives since 2005. 

From 1942 to 1992, the LANL Reports Collection was a filing point for reports issued by LANL and by 

other Department of Energy sites. There are three types of records in the Report Collection vault, which 

is located below the LANL Research Library in the Oppenheimer Study Center building at TA-3: 

classified reports in paper format, unclassified reports in paper format, and reports on microfiche. 

Approximately 3,000 classified report titles issued by LANL as LA- or LAMS- reports are located in the 

Report Collection. In the second half of the project, the project team was denied access to the following 

categories of classified information in document repositories at LANL: 

• Nuclear weapons design information, 

• Information falling under Sigma levels 14 and 15, 

• Sensitive Compartmented Information (SCI), 

• Special Access Programs (SAPs), 

• Foreign Government Information (FGI), and 

• Unclassified Sensitive Vendor Proprietary Information. 

Access to classified reports issued by any of the following entities with publication dates after 1962 was 

denied beginning March 2001: LANL, Lawrence Livermore National Laboratory, Sandia National 

Laboratory, the Defense Nuclear Agency and its predecessor and successor agencies, and DOE 

Albuquerque Area Office. During 2005, C.M. Wood of CDC reviewed the titles of Los Alamos technical 

reports that fell within this restriction and selected 18 for review. These classified technical reports were 

reviewed by a LAHDRA document analyst, and several were selected as relevant, summarized, and added 

to the project information database. 

Approximately 55-60% of the classified LANL-issued technical reports had been reviewed prior to March 

2001. Approximately 1,144 classified LANL reports issued after 1962 were not initially reviewed by the 

project team because of the March 2001 decision by LANL to withhold them. LAHDRA document 

analysts were allowed to review the titles of these withheld reports, but that approach proved to be 

ineffective and problematic due to the vagueness of many titles. All of the classified “LA-“ and 

“LAMS”-series reports issued before 1963 that were present at the Report Collection were reviewed by 

the LAHDRA team. Access to classified reports issued by entities other than LANL has been denied to 

LAHDRA analysts since November 2001. The project team had reviewed approximately 35-40% of the 

classified reports issued by entities other than LANL (up to letter “L” in the alphabetically-shelved 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary ES-5

documents) prior to the withdrawal of access. The remaining reports in this group were reviewed during 

2005 by a LAHDRA analyst working in tandem with a LANL person trained to recognize deniable 

category information. 

Approximately 10,000 unclassified report titles issued by LANL as LA- or LAMS- reports are located in 

the Report Collection vault. Images of approximately 25,000 unclassified LA-, LA-MS-, LA-UR, and 

LA-PR reports are available as PDF files in the LANL electronic library catalog. Prior to the heightening 

of security measures that followed the terrorist attacks of September 11, 2001, the unclassified “LA” 

reports were publicly available on the LANL Web site. The project team reviewed 100% of the 

unclassified “LA” reports that were formerly available without restriction on the Internet. 

There are also approximately 90,000 unclassified reports in the Report Collection vault that were issued 

by DOE sites other than LANL, academic institutions, private corporations that conducted research on 

behalf of DOE, and other defense-related agencies. The project team reviewed 70 to 75% of the nonLANL unclassified reports shelved in the Report Collection vault (up to letter “P” in the alphabetically 

shelved documents) before work was halted in 2004, and the remainder were completed early in 2007. 

There are also approximately 1.5 million documents on microfiche at the LANL Reports Collection. A 

search of two relevant databases indicated that LANL is the authoring institution for approximately 

11,000 NSA reports and 53,000 DOE Energy reports, or about 10% of each database’s contents. The 

project team completed review of the reports on microfiche in November 2006. 

The ES&H Records Center has been in operation since 1998. Its purpose is to receive records from the 

various ES&H Groups, catalogue and consolidate those records, and to eventually forward them on to the 

LANL Central Records Center. Many of the records stored at the ES&H Records Center are recent, i.e., 

from the 1990s. A total of 1,187 boxes were reviewed in the ES&H Records Center. Of these, 227 were 

deemed to contain material relevant to the project and thus had DSFs completed for them. In early 2009, 

LAHDRA analysts reviewed records that had been added to the ES&H collection since their previous 

review of those holdings. 

Reviews completed during this project also included holdings of the Weapons Engineering and 

Manufacturing (WEM) and Weapons Physics (WP) divisions. These LANL divisions are organized 

under the Directorate’s Office of the Associate Laboratory Directorate for Nuclear Weapons Engineering 

and Manufacturing (ADWEM), formerly known as Office of Associate Laboratory Directorate for 

Nuclear Weapons (ALDNW). The WEM/WP vault-type room (VTR) contained approximately 18,876 

classified documents and 1126 classified photographs. Thirty-six classified safes within the ADWEM 

main offices were also reviewed for potentially relevant information. The safes contained 7,056 

documents marked “RESTRICTED DATA”. No titles were identified as potentially relevant to the 
ES- 6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary

LAHDRA project. Based on a review of a list of classified vaults and repositories at LANL, it is 

estimated that 21 vaults, 107 VTRs, 5 alarmed rooms, and 1,600 repositories (file cabinets, 2-5 drawers 

each, with combination locks) are present. Not all of the vaults or VTRs contain only records– some 

contain weapon parts and/or special nuclear material. 

Review of documents located at the Los Alamos Neutron Science Center (LANSCE Division, formerly 

LAMPF) focused on office files within the Main Administration Building 1 located at TA-53 and the 

Radiological Air Monitoring (RAM) Records Archive. Of these documents, 2,500 were considered 

potentially relevant and underwent detailed review. Copies of 36 documents were requested and 

summarized for the LAHDRA project database. Highlights of these records are the Shift Supervisor 

Logbooks that contain daily beam current and beam-hour information dating back to 1971. Forty-five 

boxes of documents (3,375 documents) located at the RAM Records Archive (Building 3R) were 

reviewed. Copies of 97 documents were requested and summarized. This archive would be a source of 

relevant information for any future studies of off-site releases from TA-53. 

During the LAHDRA project, team members made several attempts to gain access to the contents of the 

Legal Counsel Litigation Support Database (LCLS), sometimes called the Legal Database. While the 

database itself was not made available, in late 2003/early 2004 the LAHDRA team received and reviewed 

a hardcopy listing of the documents contained in that database. The list includes document number, title, 

author, addressee and copy recipient, date, status, and page count. The LCLS database consists of the 

following document categories: H-Division, Human Studies Project Team, Central Records Management, 

“Other” documents, and Records Processing Facility documents. During 2005, LAHDRA analysts 

reviewed the hardcopy indices of the LCLS database and selected documents for review. Images of these 

documents were made available to LAHDRA analysts by Legal Counsel staff, and they were reviewed 

between May and September of 2005. Documents selected as relevant were printed and released to the 

project team. 

In February of 2006, the project team began reviewing documents held by the LANL Engineering 

Drawings Facility at TA-63. This facility housed engineering drawings and associated documents 

(memos, letters, specifications, etc.) dating back to the 1940s. The initial searching was for drawings 

pertinent to Original Technical Area buildings (especially D Building), Omega Site facilities and 

associated stacks, DP Site facilities and ventilation systems, and the Los Alamos town site. 

Approximately 1,000 historical drawings were selected as relevant to the LAHDRA project, obtained 

from LANL, and scanned to make them available via DocSleuth. The project team also completed 

systematic review of the TA-63 microfilm records, which contain correspondence and documents 

pertaining to many modifications of Lab facilities. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary ES-7

LAHDRA analysts reviewed the holdings of a small library of environmental restoration related 

documents at TA-21 and at the Environmental Restoration group’s Records Processing Facility (RPF). 

The TA-21 library was a collection of material housed in a portable building at DP West Site. Its purpose 

was to act as a resource for individuals involved in decommissioning activities there. The facility 

included binders of memoranda, remediation investigation reports, and drawings. Much of this material 

had already been collected by the project team from its review activities in the Records Center and 

elsewhere. The RPF managed records of what was formerly the Environmental Restoration (ER) group at 

LANL. Most of the holdings of the LANL Records Processing Facility, located at the Pueblo School 

Complex, had been scanned to PDF files and were available through an electronic document management 

utility called Domino. Review of this material is discussed below. In addition to these electronic records, 

the project team also reviewed some hardcopy records that existed at the RPF earlier in the project, and 

records that had recently been acquired and not yet scanned. 

 As the project team completed its systematic review activities for LANL’s centralized records collections 

it migrated its focus to records held within division or group offices. The initial focus of the review of 

division and group records was the Environmental Stewardship (ENV) Division. The ENV Division 

consisted of a large number of groups, many of which held records of interest to the project team. 

Review of these records was therefore a substantial part of the team’s activities once reviews at the 

centralized collections were winding down. Project team members also met with representatives of the 

following other LANL divisions and groups to inquire about their activities and any records they held: 

• Associate Directorate for Security and Safeguards 

• Chemistry 

• Dynamic and Energetic Materials 

• Earth and Environmental Science 

• Environmental Protection 

• Hydrodynamic Experiments 

• Industrial Hygiene and Safety 

• Materials Science and Technology 

• Plutonium Manufacturing and Technology 

• Radiation Protection 

• Weapons Component Manufacturing 

• Weapons Engineering Technology 

In May of 2006, the LAHDRA team obtained a summary of records and databases generated by the 

groups and programs within the LANL ENV Division. There were approximately 50 groups and 

programs listed, along with a number of electronic databases. Of the document collections and other 

information sources identified within the ENV Division, the largest by far was the RPF’s Domino 
ES- 8 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary

database. The Domino database was an electronic storehouse for historical and current RPF records, that 

is, environmental restoration files. These included environmental project case files, remediation 

management records, regulatory compliance records, and decontamination and decommissioning records. 

The records were stored as PDF files and managed using the IBM Lotus Domino application. Records in 

the Domino application were indexed using a unique identifier known as an ERID number. The system 

contained approximately 100,000 ERIDs, amounting to approximately 250,000 documents. Systematic 

review of the Domino records was performed by going through them sequentially by ERID number and 

reviewing the image files for those with titles that were either of potential interest or were too ambiguous 

to support a judgment. Documents deemed relevant to the LAHDRA project were printed and a DSF was 

completed. 

The project team also reviewed the RPF’s Potential Release Sites (PRS) database, which is far more 

limited in content compared to the Domino database, using the same approach as for Domino. Other 

ENV Division records collections that were reviewed include records pertinent to compliance with the 

National Environmental Policy Act (NEPA), associated environmental impact assessments, Meteorology 

and Air Quality (MAQ) group records, meteorological data, and Cultural Resources Group reports that 

include historical information about operations at LANL facilities. 

Challenges and Accomplishments in Information Gathering at Los Alamos 

Access to classified documents at Los Alamos has been more difficult than CDC personnel or LAHDRA 

team members have experienced at any of the other DOE sites that have been subjects of dose 

reconstruction investigations. The main challenges that were faced in accessing, reviewing, and arranging 

for public release of relevant documents were associated with the following issues: 

• The Cerro Grande fire, 

• security stand-downs and the fallout of security incidents involving LANL staff, 

• frequent requirements to re-establish need-to-know, 

• establishment of security plans for accessing and reviewing documents, 

• increased escorting requirements and limitations on numbers of analysts that could work 

concurrently, 

• calls by LANL staff for review of documents by titles alone, 

• establishment of seven categories of information to be withheld from the LAHDRA analysts, 

• pre-screening by document “owners” and/or classification office contractors to identify deniablecategory information, 

• difficulties in gaining access to reports issued by entities that no longer exist, 

• establishment of an appeal process for use when potentially relevant information was withheld, 

• arranging for access to documents at LANL generated by a foreign government (the UK), 

• a significant backlog of selected documents awaiting classification review and public release, 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary ES-9

• limited resources (staffing) at repositories impacting ability of LAHDRA analysts to be present, 

• a LANL shutdown in response to a security incident, and 

• initiation of pre-screening of documents by LANL Legal staff for privileged information. 

Prioritization of Airborne Releases 

During the period of LANL’s existence, many operations involving radionuclides have been performed at 

LANL, and effluents of various kinds have resulted. As the initial step towards prioritization of historical 

airborne releases from LANL, Priority Index (PI) values were calculated by computing the air volume 

required to dilute the annual activity released to be equal to the maximum effluent concentration per 

federal regulations. This priority index is intended to be a guideline to determine if a nuclide set requires 

further iterations of calculation and refinement, or if it warrants lower priority relative to other nuclides. 

For example: a PI of 104

 indicates that 104 L of air would be required to dilute the released material to a 

concentration equal to the MPC. A Microsoft Access® Off-Site Releases (OSR) Database was created to 

tabulate effluent information and to link it to existing LANL documents that have been assembled by the 

LAHDRA project team. The processes used to prioritize releases of radionuclides from LANL operations 

are described in Chapter 17. 

Prioritization of releases requires estimates of quantities that were released. There has been no 

comprehensive compilation or accounting of historical airborne radionuclide releases prepared by LANL. 

The most complete compilation of airborne radionuclide effluent data available from LANL was 

assembled in the 1970s to support preparation of a Final Environmental Impact Statement (FEIS). 

Airborne plutonium releases were prioritized based on values compiled for the 1979 FEIS and also 

documented in a 1975 publication. Values for 1948–1955 were adjusted upward by the LAHDRA team 

(by roughly a factor of 20) based on a study conducted by the LANL industrial hygiene group in 1955 and 

1956. In that study, stack releases were measured with improved, isokinetic stack sampling systems that 

were operated alongside the original systems. Correction factors were determined and applied to releases 

previously reported for 1948-1955. All values from 1948 through 1975 were adjusted further using a 

sample line loss correction factor (equal to 5 for 1945-1958 and 2 for 1959-1975) and a filter burial 

correction factor of 2.33 based on assessments performed by LANL staff. No effluent data were located 

for the wartime processing of plutonium in D Building, and LANL’s release estimates include no 

contribution from D Building during any period of its operations or from the DP West Site plutonium 

processing that occurred 1945–1947. 

Uranium usage and release data were located for 1949–1996. Available documents provide estimates of 

the quantities of uranium used in explosive testing and some results of stack sampling and analysis. 

Sample line loss and filter burial correction factors were applied to uranium stack sampling results for 
ES- 10 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary

periods prior to 1976 as was discussed for plutonium. For explosive test inventory data, Atmospheric 

Release Fractions and Respirable Fractions were applied to yield a range of Overall Release Fractions 

(ORF). The geometric mean of the ORF values, 0.001, was applied to the inventory of uranium used in 

explosive tests. 

Airborne tritium release estimates were located for 1967–1996, and no correction factors were applied. 

Prioritization of radioactive lanthanum (RaLa) releases from 254 explosive tests conducted in Bayo 

Canyon 1944–1961 was based on a source term evaluation performed by LANL personnel. The ORF 

used for uranium (geometric mean of 0.001) was also applied to reported source quantities for the RaLa 

tests. A class of airborne effluents was reported by LANL as mixed fission products (MFP) from 1961 

through 1996, with the main sources being the Omega Site (TA-2) reactors. Radioactivity included in the 

MFP “nuclide group” for prioritization included releases reported as MFP or as fission product nuclides 

such as 60Co and 137Cs. Another class of airborne effluents called mixed activation products (MAP) was 

reported by LANL for 1976–1996, with the most significant source being accelerator operations. 

Radioactivity included in the MAP “nuclide group” for prioritization included releases reported as MAP, 

Gaseous Mixed Activation Products (G/MAP), Particulate Various Activation Products ( P/VAP) and the 

air activation products 11C, 13N, 15O, and 41Ar. 

Annual values of Priority Index (dilution volume required, L) were calculated by dividing the estimated 

annual release of each category of radionuclide by the effluent concentration limit from 10 CFR 20 for a 

radionuclide representative of the radionuclide or nuclide group. The value for 239Pu was used for 

plutonium; 235U for all uranium; 140La for radioactive lanthanum, radioactive barium, and 140La; a value of 

1×10-7 μCi mL-1 from Footnote 2 to the radionuclide tables in 10 CFR 20 Appendix B was used for all 

MFP radionuclides; and a value of 2×10-7 μCi mL-1 published by the International Atomic Energy Agency 

was used for all MAP radionuclides. 

Priority Indices could be generated for the earliest years for the RaLa tests that were active 1944–1962. 

As shown in Table ES-2, Priority Index values for plutonium were the highest of all calculated Priority 

Indices overall and were higher than all other airborne radionuclide classes for 1948 through 1966 and 

again from 1970 through 1974. While uranium yielded the highest Priority Indices for 1967 though 1969, 

1975, and 1991, tritium had the highest values for 1976 and 1977 and again for 1990. Mixed activation 

product releases yielded the highest values for 1978 to 1989 and again for 1992 to 1996. 

A review and calculation was completed in October 2006 that addresses reported releases from DP West 

for 1957, using the actual daily stack reports. The results show that 40% of all operating hours were not 

monitored, mostly weekends and holidays. Therefore, a method for estimating effluent concentrations for 

the hours during which the stacks were not monitored was needed. The method used by LASL is likely 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary ES-11

conservative, in that it scales from operating hours to estimate releases during hours in which no stack 

measurement was made. The calculation also showed that some simple assumptions made in the early 

1970s, such as stack or sampler flow rates, were inappropriately used for all periods. 

Table ES-2. Classes of airborne radionuclides with highest Priority 

Indices for each period of LANL operations 

Years Radionuclide Class with 

Highest Priority Indices 

Range of Annual 

Priority Indices (L) 

1944-1947 Radioactive Lanthanum 6×1011 to 1×1013

1948-1966 Plutonium 7×1014 to 1×1018

1967-1969 Uranium 1×1017 to 1×1017

1970-1974 Plutonium 2×1014 to 3×1015

1975 Uranium 7×1013 to 7×1013

1976-1977 Tritium 3×1013 to 4×1014

1978-1989 Mixed Activation Products 6×1014 to 4×1015

1990 Tritium 1×1014 to 1×1014

1991 Uranium 1×1015 to 1×1015

1992-1996 Mixed Activation Products 6×1013 to 7×1014

The prioritization of airborne radionuclide releases indicates that plutonium was most important from 

1948 through the mid-1960s. It appears that the crudeness of LANL’s early plutonium processing 

facilities and delayed adoption of single-bank and ultimately multiple-stage HEPA filtration relative to 

other plants that were more clearly recognized as production facilities were factors in LANL becoming a 

more significant source of airborne plutonium emissions than it would otherwise have been. While 

documents discovered in this study indicate that airborne plutonium releases from LANL before the 

1970s were significantly higher than has been officially reported, the relative importance of airborne 

plutonium releases could increase with further investigation if other identified sources were characterized. 

These sources include D Building, DP West Building 12 stacks before 1948, other release points at DP 

West, early Chemistry and Metallurgical Research (CMR) Building operations beginning in 1953, nonpoint sources, accidents, and waste disposal operations. These sources were not monitored by LANL or 

reflected in estimates of plutonium historically released from the site. 

If airborne plutonium releases from DP West Building 12 stacks between 1948 and 1955 were as high as 

the 1956 reports by the Lab’s industrial hygiene staff indicate, plutonium releases from LANL could 

easily exceed the independently reconstructed airborne plutonium release totals from the production 

plants at Hanford, Rocky Flats, and Savannah River combined, even without the other sources and other 

years at LANL included. 
ES- 12 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary

The level of interest in characterizing past releases of plutonium from Los Alamos operations is 

heightened by the fact that residential areas were built closer to production areas at LANL than at any 

other major Manhattan Project, AEC, or DOE site. The nearest residences, Sundt apartments, were 

located approximately 200 m from D Building in the Original Technical Area (TA-1) and as little as 50 m 

from other key buildings in TA-1. Another housing area, a trailer park on the rim of Los Alamos Canyon 

just west of DP West site, was in use from 1948 to 1963. That housing was 1 km west of the DP West 

Building 12 stacks and was separated from Material Disposal Area B, a radioactive waste burial ground 

that experienced a major fire in 1948, by only a fence. The trailer park was also situated directly above 

Omega Site (TA-2), where five versions of nuclear reactors were operated on the canyon floor because of 

perceived dangers of associated operations. When a flexible tubing line was run up the wall of Los 

Alamos Canyon and tied to a tree atop South Mesa to serve as the release point for gases released from 

the reactors, airborne radioactivity was released at roughly the same elevation as trailer park residents. 

Airborne releases of Mixed Activation Products from accelerator operations appear to have been most 

significant in a majority of years after the 1970s, by which time controls and monitoring of other airborne 

effluents such as plutonium had significantly advanced. Uranium releases yielded relatively high Priority 

Indices for the late 1960s, 1975, and 1991, but in general associated values were lower than those for 

plutonium. The uranium releases reported by LANL for 1967-1969 appear to be anomalously high, and 

some quantities documented as released might actually have been amounts of uranium used in explosive 

testing, with no accounting for the fraction aerosolized in the tests. 

Airborne tritium releases yielded the highest Priority Indices of all radionuclides in the mid-1970s and in 

1990, but the true importance of the radionuclide cannot yet be definitively evaluated because of the 

scattered and incomplete nature of effluent measurements or estimates prior to 1967. Incident reports 

indicate that sizable episodic releases of tritium occurred between the mid-1940s and 1967, the earliest 

year for which reports of tritium releases were compiled by LANL. 

Prioritization of Waterborne Radionuclide Releases 

Priority Indices for waterborne radionuclides were calculated for total plutonium, 238Pu, 239Pu, 89Sr, 90Sr, 

tritium, gross alpha, and gross beta radioactivity. That assessment is described as part of Chapter 17. 

Estimates of historical releases were obtained from the compilation of data for the 1979 FEIS, from 

excerpts and compilations of AEC effluent records, and from annual environmental surveillance reports 

that were issued by LANL beginning in 1971. No summary waterborne effluent data were found for the 

years 1974-1976. Priority Indices were calculated by computing the volume of liquid required to dilute 

the annual activity released to be equal to the maximum effluent concentration per 10 CFR 20. The 

maximum effluent concentration for 239Pu was used to calculate the Priority Indices for gross alpha 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary ES-13

radioactivity while the maximum effluent concentration for 89Sr was used for gross beta radioactivity. 

The waterborne radionuclide classes that yielded the highest Priority Indices for each period from 1945 

through 1996 are identified in Table ES-3. 

Table ES-3. Classes of waterborne radionuclides with highest PIs for periods of LANL operations 

Years Radionuclide Class Range of Annual 

Priority Indices (L) 

1945-1952 Plutonium 5×1010 to 1×1011

1953-1954 Strontium-90 3×108 to 3×108

1955-1957 Gross alpha radioactivity 8×108

 to 5×109

1958 Plutonium 5×109

 to 5×109

1959 Gross beta radioactivity 6×108

 to 6×108

1960-1963 Gross alpha radioactivity 6×108

 to 4×1010

1964 Gross beta radioactivity 3×108

 to 3×108

1965-1968 Gross alpha radioactivity 2×108

 to 8×108

1969 Plutonium 4×108

 to 4×108

1970-1973 Gross alpha radioactivity 4×108

 to 8×108

1977-1980 Plutonium-238 9×107

 to 4×108

1981-1989 Plutonium-239 1×108

 to 3×109

1990-1992 Strontium-90 3×107

 to 5×108

1993 Plutinium-239 5×107

 to 5×107

1994-1996 Plutonium-238 1×108

 to 2×108

Preliminary prioritization analyses for waterborne radionuclides indicated that plutonium releases were 

most important for just over half of the years of LANL operations between 1945 and 1996 for which 

effluent data are available (27 y out of 49). Liquid radioactive waste was discharged to Acid-Pueblo 

Canyon without treatment or monitoring from 1945 through 1950, prior to a treatment plant becoming 

operational in 1951 and an improved plant in 1963. 90Sr appears to have been most important for several 

years in the mid-1950s and early 1990s, while gross alpha-emitting radioactivity was most important for 

most years between 1955 and 1973 and gross beta-emitting radioactivity yielded highest Priority Indices 

for 1959 and 1964. Unlike airborne tritium releases, which were not quantified by LANL prior to 1967, 

waterborne releases of tritium were quantified beginning with 1945 but appear to have been less 

important than the other radionuclides reported to have been present in liquid effluents. 

Measurements of Plutonium in Soil as Indicators of Historical Releases 

Because releases of airborne plutonium from LANL were either not measured at all or were poorly 

quantified and reported until around 1978, the LAHDRA team recognized a need to estimate potential 

releases from LANL operations using methods beyond those based on reported stack monitoring results. 
ES- 14 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary

One method identified was to use amounts of plutonium measures in soil samples collected around Los 

Alamos to estimate the amount of airborne plutonium that was released. That assessment is described as 

part of Chapter 17. Scientists at LASL attempted to measure the amount of plutonium in the soils around 

LANL in the 1957-1958 timeframe. Their effort was documented in a 1958 publication “Evaluation of 

the Air Pollution Problem Resulting from Discharge of a Radioactive Effluent” by Harry Jordan and 

Ralph Black. Based on analyses of soil samples collected along circles of increasing distance from the 

main stacks at DP West Site (up to a radius of 1 mi), the authors asserted that they were able to compare 

release estimates that they generated with the releases calculated by LANL staff based on stack sampling 

at DP West. Jordan and Black selected results from only six of about 40 sample locations because they 

“show rather remarkable agreement” with the LANL stack effluent records that were said to show that 

13.1 g or 0.82 Ci of plutonium had been released. Results that were substantially higher were not used 

because they were thought to be higher because of failure of “attempts to avoid extraneous 

contamination.” 

Although Jordan and Black asserted agreement with release estimates based on stack sampling, they were 

apparently unaware of or ignored major changes in the stack sampling system in 1955 that were the 

subject of a study by Edwin Hyatt that resulted in significant modification of release estimates for 1948 to 

1955. LANL has been unable to produce, and LAHDRA analysts have been unable to find, any 

supporting records or logbooks about the referenced work. Jordan and Black excluded any high samples 

for reasons that do not appear to be well justified. It now appears that the associated measurements of 

radioactivity in soil used too large of a volume of soil, resulting in low and variable recovery of 

plutonium from soil in the acid leaching process. And perhaps most importantly, the radiochemist 

responsible for the analyses has stated that his results were only intended to be qualitative (whether 

plutonium was present or not) rather than quantitative (how much plutonium is present). 

As a result of the lack of effluent measurements for early airborne releases of plutonium, the LAHDRA 

team has considered several nontraditional methods to gain information about the potential magnitude of 

historical plutonium releases. Measurements of plutonium in soil around LANL make up an 

“environmental record” that is a potentially useful indicator of past releases. Members of the project team 

have performed several iterations of analysis to estimate the total airborne plutonium release that would 

be consistent with the environmental record of plutonium found in soil samples in the Los Alamos area. 

The initial iteration of the assessment by LAHDRA team members to estimate airborne plutonium 

releases was based on 37 measurements of plutonium in soil samples collected near Los Alamos from 

1975 to 1977. These measured concentrations of 239Pu in soil included global fallout from atmospheric 

testing of nuclear devices. The average concentration of 239Pu of distant sample sites (approximately 50 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary ES-15

mi from LANL) was subtracted from the 37 values used in the analysis. The “corrected” soil 

concentrations reflected 0.003 to 0.045 pCi g-1 net positive contributions of 239Pu from LANL operations. 

The Radiological Safety Analysis Computer (RSAC) program was run with LANL meteorological data to 

calculate 239Pu deposition at various distances in each direction from a unit release (1 Ci) of 239Pu over 50 

y. The calculated deposition at each distance was converted to a soil concentration based on the annular 

area involved and the soil density and sampling depth reported by LANL. The ratio of each measured 

soil concentration to the concentration calculated for that same area from the RSAC modeling of a unit 

release yielded a factor that corrects the unit source in RSAC to give agreement between the soil data and 

the RSAC results. For example, a ratio of 15 would indicate that 15 Ci of plutonium had been released 

rather than the 1 Ci assumed. The ratios over the 37 sampling locations were log-normally distributed. 

Based on the distances involved with releases from D Building, the geometric mean (GM) was 620 Ci, 

with a factor of uncertainty (geometric standard deviation of the mean, GSD) of 1.2. For the distances 

associated with releases from the DP West Site the GM was 670 Ci, with a factor of uncertainty of 1.3. 

While these results have a high degree of uncertainty, they indicated that airborne plutonium releases 

from LANL operations could have been hundreds of times higher than the 1.2 Ci officially reported. 

Following the initial analyses, additional soil sampling data was obtained, and a new analysis was 

performed using this expanded dataset of 679 soil samples from 34 locations. Of these, 106 samples at 24 

sample points were judged impacted by LASL operations based on analysis of the plot of plutonium-tocesium ratios. In the second approach, a total uncertainty for each soil sample was calculated, and only 

those measurements with uncertainty in the plutonium to cesium ratio less than 25% were analyzed. For 

these 37 samples, the net plutonium and the range and bearing from the D Building and DP West Site 

were calculated. RSAC was used to calculate the soil concentration as a function of wind direction and 

distance for a unit release. When divided into the net sample data, an estimate of the integrated LANL 

source term was obtained for each of the 37 samples. If the release was attributed to the DP West Site, an 

average of 60 Ci and a median of 12 Ci were obtained with a GSD (factor of uncertainty) of 9. If the site 

releases were attributed solely to D Building, an average of 101 Ci and a median of 46 Ci were obtained 

with a corresponding GSD (factor of uncertainty) of 5. 

Analysis of Measurements of Plutonium in Body Tissues of Los Alamos Residents 

The LANL Human Tissue Analysis Program was a 35-y effort by LANL to study the levels of plutonium 

in workers and in the general population of the United States. The collection and analysis of tissues was 

intended to answer questions about the behavior of plutonium in the human body. In later years, the 

program was expanded to other areas of the country in order to estimate the amount of nuclear fallout 

people were subjected to from the atmospheric testing of nuclear weapons. The non-worker tissue 
ES- 16 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary

program ended in 1980. Nearly 1,000 decedents had tissues removed during their autopsies and sent to 

LANL by coroners. 

The LAHDRA staff attempted an independent analysis of the autopsy program results. This effort, 

described as part of Chapter 17, demonstrated that excess plutonium is present in non-worker residents of 

Los Alamos over what would be expected from global fallout from nuclear weapons testing. It also 

established and tests a method for uncovering the history of residence locations for autopsy cases. This 

history establishes the range and bearing from LANL release points along with the years of occupancy at 

each residence. This method could be used to reduce the uncertainty in retrospective dose reconstructions 

and possibly permit use of the autopsy data for bounding LANL releases. 

The autopsy data reported by McInroy et al. in 1979 shows that the cumulative frequency distributions 

(CFDs) of liver concentrations (dpm kg-1 liver) are nearly identical between Los Alamos and Denver. 

However, the vertebrae autopsy samples from Los Alamos are higher than Denver, and their different 

slope indicates the plutonium has been in the body longer. If Los Alamos indeed had one half (or less) of 

the fallout as Denver, as documented by Purtymun and Krey, the liver results should show this. However, 

this is not the case. The liver data would seem to indicate the plutonium present at Los Alamos is roughly 

equal that of Denver. If one accepts the earlier fallout data from Purtymun and Krey, then this implies 

that the “extra” or “added” plutonium (that which makes the plutonium liver concentrations equal) is due 

to LANL emissions. The liver results show that autopsy samples from residents of Los Alamos appear to 

have “added” plutonium. If there were two distinct populations among those exposed around Los 

Alamos, one might expect to see a bend in the CFD curve indicating added plutonium in the fraction of 

the population living nearest the release points. However, no bend is seen. It is likely that releases from 

the site were not sufficient to cause this “bend” in the CFD plot or that the inherent variability of various 

factors dominates the distribution and masks the presence of two populations. 

The vertebrae results show differences between Los Alamos and Denver, with the differences occurring 

in the population with higher bone concentrations. This result also appears to be consistent with a 

hypothesis that releases at Los Alamos impacted the population. The data also show significant 

divergence in the ratio of concentrations in the skeleton to that of the liver. Cumulative frequency 

distribution graphs for the ratio of vertebrae results to those of liver were analyzed for all autopsy cases 

that had data for both organs. An exponential function provides a good fit to the data, which implies that 

the data are log-normally distributed. The median value, read from the chart at zero for the “X-Axis”, 

shows a value of 1.73 for Denver, corresponding to less-aged exposures. Los Alamos shows a median 

value for the vertebrae-to-liver ratio of nearly 2.72. The geometric standard deviation is 2.3 times larger 

for Los Alamos compared to Denver. If the air concentration had been constant over time, this would be 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary ES-17

a ratio indicative of exposure that began about 10 y prior to autopsy. Given the large values of the ratio 

for Los Alamos, these data indicate that exposures in the early years were higher than the later years. 

To reduce the uncertainties of the analyses of human tissue samples, death certificates and a case index 

key for participants in the autopsy program that were found in the LANL Archives during 2006 were used 

to develop residence histories for each autopsy case. Starting with the information on the death 

certificates, the LAHDRA team used telephone directories, obituaries, marriage licenses, and other public 

records to recreate the residential history of each decedent to the extent possible. In total, there were 236 

autopsy cases for the Los Alamos area for which tissue activity data were available, with 60 of those 

participants having been LANL employees. Associated with these participants were 809 residential 

locations, of which 677 were identified as addresses and 542 could be geocoded using an Internet-based 

service so that distance to D Building and DP West could be calculated. For some addresses, a global 

positioning satellite (GPS) unit was used to determine coordinates. In some cases, the historical address 

is no longer a residence. To support spatial analysis, coordinates were obtained for the addresses of the 

participants using TeleAtlas®. For each address, range from D Building and DP West were calculated. 

Solutions of the original samples taken under the LANL human tissue analysis program, as well as 

logbooks associated with the program, have been maintained by the United States Transuranium and 

Uranium Registries (USTUR) for many of the autopsy cases. Because of that, it may be possible to 

determine how much of any autopsied individual’s exposure was due to fallout or releases from LANL. 

A new method of measurement called Inductively Coupled Plasma Mass Spectrometry (ICP-MS) can 

distinguish between weapons-grade plutonium that has not been used in a nuclear weapon and plutonium 

from fallout that resulted from a nuclear detonation. USTUR has performed an initial study of the method 

with promising results. This method and new analysis of the samples might permit more accurate 

estimation of how much of the plutonium found in the tissues of any former Los Alamos resident was due 

to global fallout and how much was due to releases of plutonium from LANL. 

Prioritization of Chemical Releases 

Operations at LANL have involved many non-radioactive materials, including metals, inorganic 

chemicals, and organic chemicals including solvents. To prioritize chemical releases, chemical use and 

release data were extracted from chemical inventories and various LANL documents. Details regarding 

these data sources can be found in Chapter 19. Prioritization of chemicals took into account estimates of 

annual usage and U.S. Environmental Protection Agency (USEPA) toxicity values such as cancer potency 

slope factors and reference doses (RfDs). Chemicals that were considered carcinogenic were ranked 

based on estimated annual usage multiplied by the applicable cancer slope factor. Oral slope factors were 

used in all but one case because they provided a more conservative (higher) estimate of toxicity for 
ES- 18 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary

prioritization than the inhalation slope factors. All chemicals with published RfDs were ranked by 

dividing the annual usage by the applicable RfD. For agents that have both ingestion and inhalation 

RfDs, the more conservative (lower) value was used. Table ES-4 presents a ranking of each chemical that 

was documented as used at LANL, for which some usage quantity information was obtained, and for 

which a cancer potency slope factor and/or reference dose has been published. 

The prioritization of chemical releases based on their potential to cause cancer indicated that four of the 

top five ranked chemicals were organic solvents, which were commonly used in chemical processing and 

for cleaning of metals and other materials. Trichloroethylene ranked highest, indicating highest relative 

potential for health effects, for both cancer and non-cancer effects. For chemicals with cancer potency 

slope factors and some usage data available, 2,4,6-trinitrotoluene (TNT) yielded the highest ranking for a 

material that was not a solvent, while uranium as a heavy metal toxin ranked highest for non-cancer 

effects among materials that are not solvents, followed by TNT. 

Development of Residential Areas in Los Alamos 

Evaluation of off-site exposures from activities at Los Alamos technical areas would require 

documentation of the development of nearby residential areas over time. While it was initially thought 

that the 31 houses commandeered from the Los Alamos Ranch School and Anchor Ranch would provide 

sufficient housing for the projected staff of 30 scientists and their families, it soon became clear that the 

scope of the challenge to provide housing for Los Alamos residents had been severely underestimated. 

Pressure to provide housing and the limited availability of suitable land in the region of finger-like mesas 

and canyons led to the development of housing that in some cases was much closer to operational areas 

than has become customary for government facilities that undertake processing of nuclear materials and 

high explosives and/or operation of devices such as reactors or high-energy particle accelerators. 

Based on reviews of historical documents that were performed, nine locations were identified as being 

among the sites where historical operations took place that appear to warrant evaluation in terms of 

potential off-site releases or health effects. The LAHDRA project team collected maps, photographs, and 

historical documents that describe the history of development of each Los Alamos housing area. The 

assembled information is summarized in Chapter 15. For each of the nine locations of interest, the 

following parameters were evaluated to support evaluation of the potential for public health effects: 

• The distance from the area to housing areas that were in place during the period(s) that associated 

operations were active, 

• The direction from the location to each housing area, and 

• The prevalence of winds from the location toward each the housing area. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary ES-19

Table ES-4. Ranking of LANL chemicals based on toxicity parameters and indicators of annual usagea 

Slope Factor 

(SF) 

Reference 

Dose (RfD) 

Peak 

annual use 

Ranked based on 

cancer effects 

Ranked based on 

non-cancer effects 

Chemical (mg kg-1 d-1)-1 (mg kg-1 d-1) (kg) Use × SF Rank Use × RfD-1 Rank 

Acetone - 0.9 18,800 - 20,889 13 

Benzene 0.055 0.004 181 10 7 45,250 9 Carbon tetrachloride 0.13 0.0007 558 73 5 797,143 5 Chlorodifluoromethaneb - 14.3 32,200 - 2,252 17 Chloroformc 0.0805 0.01 3,088 249 4 308,800 7 Dichlorodifluoromethaneb - 0.0571 32,200 - 563,923 6 Dioxane 0.011 - 32 0.35 8 - Methanol - 0.5 6,600 - 13,200 14 Methyl ethyl ketone - 0.6 22,000 - 36,667 12 Methylene chloride 0.008 0.06 2,200 17 6 36,667 11 n-Hexane - 0.06 304 - 5,067 16 Tetrachloroethylene 0.54 0.01 10,540 5,692 2 1,054,000 4 TNT (2,4,6-trinitrotoluene) 0.03 0.0005 37,950 1,139 3 75,900,909 3 Toluene - 0.08 3,300 - 41,250 10 Trichloroethane (methyl chloroform) - 0.2 39,300 - 16,500 8 Trichloroethylene 0.4 0.0003 27,719 11,088 1 92,396,667 1 Uranium (as a heavy metal) - 0.0006 47,500 - 79,166,667 2 Xyleneb,d - 0.0286 290 - 10,140 15 

a All toxicity parameter values were obtained from Oak Ridge National Laboratory, Risk Assessment Information System. b The inhalation RfD was used because it was more conservative than the oral RfD. In all other cases, oral RfDs were used. c The inhalation SF was used because it was more conservative than the oral RfD. In all other cases, oral SFs were used. d Combined congener values were used (combined, p-, m-, o-).
ES- 20 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary

Screening-Level Assessment of Airborne Plutonium Releases 

Because airborne plutonium releases from DP West site were documented to have been significantly 

higher than officially reported, a screening assessment using the methodology of National Council on 

Radiation Protection and Measurements (NCRP) Report No. 123 was performed for releases from DP 

West Site Building 12 stacks during 1949, the apparent year of peak emissions. That assessment is 

described in Chapter 18. In Level I screening, the release of 86.6 g of 239Pu from the Building 12 stacks 

in 1949 was converted to an average stack concentration based on documented annual exhaust volume. 

Level I screening uses the simplest approach and incorporates a high degree of conservatism to avoid 

underestimating doses to people. Based on the assumption made in Level I screening that the wind blew 

toward the closest potentially exposed individual (a resident at the trailer park located 1 km west of the 

stacks) 25% of the time, concentrations at that point were estimated as one-quarter of that stack 

concentration. The exposure point concentration (Bq m-3) was multiplied by the all-pathways screening 

factor (Sv per Bq m-3) from Table 1.1 of NCRP Report No. 123 to yield a screening value that was 

compared to a limiting value. The limiting value was set at 1.67×10-4 Sv y-1 based on 1 in 100,000 added 

risk of fatal or non-fatal cancer using a risk factor of 6.0×10-2 Sv-1. 

Level II screening as proceduralized by the NCRP accounts for dispersion in the atmosphere and 

combines all significant pathways into a single screening factor. The atmospheric concentration at the 

exposure point was estimated using a straight-line Gaussian dispersion model, and the resulting 

concentration was multiplied by the atmospheric screening factor from Table 1.1 of NCRP Report No. 

123 to obtain the Level II screening value. In accordance with NCRP recommendations, that screening 

value was compared to 10% of the limiting value in recognition of uncertainties inherent within the 

calculations and associated assumptions. 

In Level III screening, which includes more definitive pathways analysis, the exposure point air 

concentration from Level II screening was multiplied by a screening factor for inhalation and external 

sources/submersion from Table 1.1 of NCRP Report No. 123 and by a second screening factor for 

vegetable consumption from the same table to obtain screening values for inhalation and external 

exposure as well as for consumption of home grown vegetables. Historical documents and interviews 

with residents of Los Alamos indicate that residents were allowed to maintain vegetable gardens after 

World War II, including at the trailer park west of DP Site, but no evidence has been found of production 

of animal food products within the townsite. The two screening values were summed and compared to 

the screening limit (i.e., the limiting value divided by 10 as in Level II) to determine whether further 

evaluation of historical exposures is warranted. 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary ES-21 

The results of preliminary screening of airborne 239Pu releases from DP West site Building 12 stacks 

during 1949 are presented in ES-5. In Level I and Level II screening, the screening value exceeded the 

limiting value by at least four orders of magnitude, prompting application of the screening methodology 

at the next highest level. It is important to emphasize that the results of the screening calculations are 

strictly for comparison with an environmental standard (limiting value), to determine if compliance with 

that standard is assured or further investigation is warranted. The screening values are not intended to 

represent estimates of actual doses to individuals. The results of Level III screening, which again 

exceeded the limiting value by over four orders of magnitude, indicate that airborne 239Pu releases from 

Building 12 stacks– as represented by estimated releases during 1949– warrant further evaluation by 

experts in environmental radiological assessment. 

Table ES-5. Summary of the preliminary screening of airborne 239Pu releases from DP West Site 

Building 12 stacks during 1949

 

Level of 

Screening 

Features of Screening 

Methodology 

Screening 

Value 

(Sv y-1) 

Screening 

Limit 

exceeded? 

NCRP Guidance 

I 

Vent air, all pathways, 

concentration at exposure point set 

equal to 25% of stack 

concentration. 

313 Yes Proceed to Level II 

II 

Vent air, all pathways, Gaussian 

plume modeling to exposure point 

outside near-wake region, wind 

blows toward exposure point 25% 

of the time. 

0.367 Yes Proceed to Level III 

III 

Vent air, specific pathways 

(inhalation, external exposure, 

consumption of vegetables), same 

dispersion assumptions as Level II. 

0.367 Yes 

"Seek assistance from 

experts in environmental radiological 

assessment" 

Screening-Level Assessment of Airborne Beryllium Releases 

A screening assessment of beryllium concentrations in public areas was performed based on information 

from historical documents and the atmospheric dispersion screening methods of NCRP Report No. 123. 

That assessment is described in Chapter 20. Peak releases of airborne beryllium from the “new” SM-39 

Shops at TA-3 for years after 1963 were estimated based on documented annual releases for 1964-1966 

and 1968-1970, within which the highest value was for 1970. Peak SM-39 Shop releases representative 

of 1953-1963, before high efficiency particulate air (HEPA) filters of nominal 99.97% efficiency were 

added, were estimated based on 1970 releases multiplied times a factor of 167. That value is the ratio of 
ES- 22 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary

the effluent reduction factor for HEPA filters to the reduction factor for the filters (of assumed 95% 

efficiency) that were in place before HEPA filters were installed. Because of similarity of operations, 

peak release rates of airborne beryllium from V Shop at TA-1 for 1943 to 1953 were assumed to be equal 

to those from the SM-39 shop before HEPA filters were added. 

Releases from the hot pressing of beryllium oxide (BeO) powder in Q Building at TA-1 were estimated 

based on a document that indicates that 6,100 lbs of BeO was obtained during 1944 for production of 

reactor components. Based on an assumed release fraction of 0.25%, it was estimated that 6,900 g of 

BeO (containing 2,500 g of beryllium) was released over 1,600 working hours in 1944. Releases from 

the testing of beryllium-containing atomic weapon components fired from a cannon in an annex to B 

Building at TA-1 were estimated based on a frequency of 1 shot per day, 7 d per week. LAHDRA team 

members estimated that each 20-mm diameter projectile contained 120 g of beryllium, of which 10% was 

aerosolized, yielding a release of 12 g per test over a 6-minute period. Peak beryllium releases from 

explosive testing at the Pulsed High Energy Radiographic Machine Emitting X-rays (PHERMEX) facility 

at TA-15 were estimated based on a report that beryllium use in explosive tests peaked at 106 kg in 1964. 

The calculation assumed that 100 shots occurred in 1964, of which 80% did not involve beryllium and 

20% did. Of the 20 shots that used beryllium, it was assumed that 16 used 3.31 kg beryllium and four 

used 13.25 kg. If 10% of the beryllium in one of the larger shots was aerosolized, 1.325 kg would have 

been released over 15 min. 

For the beryllium shops and oxide pressing operations, release or usage estimates were found only in the 

form of annual totals. In order to estimate how high release rates could have been over shorter periods, 

detailed monitoring data that are available for airborne plutonium releases from DP West site stacks for 

1956 and 1957 were analyzed. The relationships between daily concentrations and weekly, monthly, and 

annual average concentrations were characterized, and a table of multipliers was generated that can be 

applied to annual data to estimate peak releases over a series of shorter durations. To support preliminary 

screening, airborne beryllium releases were assumed to vary over time like the measured airborne 

plutonium releases, and annual beryllium releases were converted to release rates over shorter durations 

so that airborne concentrations could be compared to occupational and ambient exposure limits. 

For each beryllium emission source, the distance to the nearest residential area was estimated, and 

dilution factors were estimated using the method of NCRP Report No. 123’s Gaussian plume modeling of 

releases to the atmosphere. The estimated exposure point concentrations were compared to occupational 

and ambient concentration limits. 

The results of screening of airborne releases from the beryllium operations are presented in Table ES-6. 

The release rate and concentration values for BeO powder pressing, V Shop, and SM-39 Shop releases are 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary ES-23 

presented as 6-min, 30-min, and 8-h average values that would be expected to be reached or exceeded 

once per year and monthly average concentrations that would be expected to be reached or exceeded 5% 

of the time. For the explosive tests at TA-15, the results in Table ES-6 for periods longer than a week are 

average values over the periods shown based on 100 shots/y, each with 0.25-h duration, that together 

released 10% of the total beryllium reported expended in 1964. For periods shorter than a month, the 

results are average values over the periods shown based on one shot, with 0.25-h duration of exposure, 

occurring during the period and releasing 1.25% of the total beryllium reported expended in 1964. 

The screening results indicate that the 8-h time weighted average permissible exposure limit of 2 μg m-3

for beryllium adopted for workers by the Occupational Health and Safety Administration (OSHA) and the 

AEC could have been exceeded in residential areas by releases from the B-Building gun tests. The 

OSHA/AEC ceiling limit of 25 μg m-3 for workers could also have been exceeded for releases from those 

tests based on concentrations estimated for 0.5-h and 0.1-h averaging periods. The USEPA reference 

concentration of 0.02 μg m-3 could have been exceeded in residential areas by releases from B-Building 

gun testing, BeO powder pressing, V-Shop machining, and tests at PHERMEX. The National Emission 

Standard of 0.01 μg m-3 for beryllium in ambient air averaged over a 30-d period could have been 

exceeded in residential areas from the B-Building gun tests and BeO powder pressing. 

The importance of the early beryllium releases is again heightened by the fact that residential areas were 

unusually close to the original Technical Area, with the nearest residences roughly 50 m from B Building, 

which was literally across Trinity Drive from numerous Sundt apartments. Sigma, Q, and V Buildings– 

which all housed beryllium operations– were all within 170 m or less of the nearest residences. While it 

is clear that beryllium was viewed as an occupational hazard after 1947, it appears that the potential for 

public exposure has not been fully evaluated. 

Screening-Level Assessment of Airborne Tritium Releases 

The benefits of incorporating tritium into nuclear weapons design was recognized early in the Manhattan 

Project. Information regarding tritium uses is summarized in Chapter 7. Project Y personnel requested 

tritium from Oak Ridge, TN in the spring of 1944. While LASL received tritium in increasing quantities 

over the decades for use at 10 or more TAs, no airborne tritium effluent data were included in LANL 

compilations of effluent data for years prior to 1967. Tritium was released to the air at TAs 3, 21, 33, 35, 

and 41. In addition, tritium was used in firing site (explosive testing) activities, at TA-15 for example. 

Between 1967 and 1995, annual airborne tritium releases reported by LANL were never lower than 

10,700 Ci and peaked at 38,600 Ci in 1977. Scattered incident reports located by LAHDRA analysts 

describe episodic releases of tritium that total as much as 64,890 Ci in 1965 and 39,000 Ci as early as 
ES- 24 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary

Table ES-6. Results of a preliminary screening assessment of airborne beryllium concentrations in residential areas from identified emission sources at LANL

B-Building 

Gun Testsa

BeO 

Powder 

Pressing 

V Shop 

1943-48 

V Shop 

1949-53 

SM-39 

Shop 1953 

to 1963 

SM-39 

Shop after 

1963 

PHERMEX 

Testsa

Distance to exposure point (m) 49 140 170 170 960 960 4500 Relative concentration (s m-3) 1.1×10-2 2.5×10-4 1.1×10-4 1.1×10-4 6.9×10-6 6.9×10-6 2.5×10-6Release rates (μg s-1) for relevant averaging periods; 

0.1 h: 33,000 64,000 12,000 610 610 3.7 1,500,000 0.5 h: 6,700 20,000 3,900 190 190 1.2 740,000 8 h: 420 3,600 680 34 34 0.20 46,000 730 h ( 1 month): 140 150 29 1.4 1.4 0.0086 670 

Exposure point concentrations (μg m-3) for relevant averaging periods; 

0.1 h: 350c,d 16d 1.4d 0.069d 0.0042 0.000025 3.7d0.5 h: 71c,d 5.1d 0.44d 0.022d 0.0013 0.0000080 1.8d8 h: 4.4b,d 0.90d 0.077d 0.0038 0.00023 0.0000014 0.12d730 h ( 1 month): 1.5d,e 0.038d,e 0.0033 0.00016 0.000010 0.000000059 0.0017 

a Episodic releases b Possible exceedance of OSHA/AEC 8-h time weighted average limit = 2 μg m-3c Possible exceedance of OSHA/AEC ceiling limit = 25 μg m-3d Possible exceedance of USEPA Reference Concentration = 0.02 μg m-3e Possible exceedance of National Emission Standard for ambient air averaged over a 30-d period = 0.01 μg m-3
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary ES-25 

1958, each from within the 22-y period of tritium usage for which official reports of LANL releases 

include no data for the radionuclide. LANL did not begin monitoring tritium stack releases until 1971. In 

1973, the Lab prepared estimates of atmospheric releases for 1967 through 1970 based on accountability 

data. There are no formal estimates of total tritium releases prior to 1967, though the LAHDRA 

document collection contains effluent monitoring and other tritium release data for some tritium facilities 

prior to 1967. How complete a picture this information might represent with regard to LANL’s total 

atmospheric tritium releases for the pre-1967 period is currently unknown. Mid-way through the project, 

the LAHDRA team made a limited effort to compile tritium effluent data from its document collection 

into a database. Specifically, the focus was on the Lab’s formally reported tritium releases for the period 

from 1967 forward. These data were entered into a database known as the Off-Site Releases (OSR) 

database as an internal tool used by the LAHDRA team to support prioritization of historical radionuclide 

releases from LANL. 

One of the most important factors to consider in evaluating atmospheric releases of tritium for potential 

health risks is the chemical composition of the release. The difference between tritium gas and tritium 

oxide is enormous in terms of radiation dose to a human receiver. If inhaled, tritium gas is not 

incorporated into the body to any appreciable degree, and the only dose consequence is the direct 

exposure to lung tissue. Tritium oxide, in contrast, behaves as water and is readily incorporated into body 

tissues. In terms of radiation dose per unit intake, the dose from tritium oxide exceeds that from tritium 

gas by four orders of magnitude (ICRP 1996). 

Given its application in the weapons program and accelerator operations, tritium at Los Alamos has 

primarily been used in the form of tritium gas. However, there are some circumstances where an 

assumption of the oxide form is appropriate, at least for purposes of initial screening. Examples would 

include the use of tritium in explosive testing and operations involving water reactions with tritiumbearing salts resulting in oxide formation. 

The NCRP Report No. 123 screening method for radionuclide releases to the environment was used to 

evaluate atmospheric tritium releases from LANL in terms of their potential risk to local residents. That 

assessment is described in Chapter 7. The source term used was the maximum release reported for each 

of the six TAs that represented the largest contributors to LANL’s atmospheric tritium releases. To 

ensure a meaningful screening result, these release totals were re-stated in terms of the corresponding 

tritium oxide activity for each total value. The upper bound for the fraction of a tritium gas source that 

has converted to an oxide form was taken to be 1% based on published studies (see Chapter 7). 

 Screening was performed against a criterion of a 1 in 100,000 added risk of fatal or non-fatal cancer, 

assuming a risk factor of 6% per sievert (Sv). This corresponds to a dose equivalent of 1.67×10-4 Sv. The 
ES- 26 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary

exposed population selected for each screening assessment was the residential population nearest each 

release point. The pathways considered for each residential location were inhalation of contaminated air 

and consumption of contaminated soil and vegetables. Consumption of locally raised meat or milk were 

not considered. 

A Level I screen was performed for the TA-3 release first, since it was the smallest contributor to the 

tritium oxide source term. The Level I screening evaluation for the TA-3 tritium releases exceeded the 

screening criterion by a substantial margin. Screening therefore proceeded to Level II/III. 

In the Level II screening process, the estimated distances from the release points to the nearest residential 

locations were used to determine a plume diffusion factor from plots provided in NCRP Report No. 123. 

The Level II screening evaluations showed that only in the case of TA-35, for which the maximum 

release was treated as 100% HTO, was the adjusted screening criterion exceeded. 

The screening-level evaluation suggests that airborne tritium releases from LANL after 1966 were 

unlikely to have been a source of health risks to local residents around Los Alamos that warrants high 

priority in any assessment of historical releases from LANL. The possibility cannot be ruled out entirely, 

however, in light of the screening result for TA-35. The situation could change if releases consisted of a 

greater fraction as tritium oxide than has been considered here. However, given the degree of 

conservatism used in application of the NCRP screening method, it appears the impacts of such effects 

would have to have been substantial before atmospheric tritium releases after 1966 would have posed a 

significant health risk. Tritium releases events before 1967 are described in numerous scattered 

documents found by the LAHDRA team, but release totals have not been compiled that would support an 

evaluation of potential off-site exposures. Airborne tritium releases before 1967 represent a notable data 

gap in what is known about historical releases from Los Alamos operations. 

Screening-Level Assessment of Airborne Uranium Releases 

Uranium, at various levels of 235U enrichment, has been used in a wide variety of applications at Los 

Alamos. Information about uranium use is summarized as part of Chapter 9. Uranium was used as a 

fissile material in atomic weapons and in “tampers” that confined the explosion, reflected some neutrons 

that would otherwise escape, and thereby decreased the critical mass of fissile material required to 

achieve an atomic explosion. Uranium was also used in liquid and solid forms as fuel in various forms of 

nuclear reactors developed and tested at Los Alamos. Some LASL facilities, including DP East Site, 

produced fuel for reactors operated elsewhere, such as those in the Rover program. DP West Site’s 

Building 4 housed laboratories for production of enriched uranium hydride, then was converted to a hot 

cell facility for examination of irradiated plutonium and enriched uranium fuel elements. Uranium was 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary ES-27 

also used in explosive testing at Los Alamos– LASL staff estimated in 1971 that between 75,000 and 

95,000 kg of uranium had been expended in experimental shots at the Lab from 1949 through 1970. 

In the Original Technical Area (TA-1), uranium was processed in a ”normal” uranium machine shop in C 

Building’s southeast section, in chemistry and metallurgical experiments in D Building, in the HT (Heat 

Treatment) Building. Enriched uranium processing, metallurgy, and recovery were conducted in M 

Building, while normal and enriched uranium were cast and machined in Sigma Building; the eastern 

portion of the building processed normal uranium while the western portion processed enriched uranium. 

TU Building housed machining of normal uranium (“tuballoy”), while TU-1 Building housed recovery of 

enriched uranium. The original machine shop in V Building machined uranium and beryllium. 

The Sigma Complex in TA-3, built in the 1950s and 1960s, has housed extensive laboratory areas for 

materials synthesis, and processing, characterization, and fabrication of materials such as beryllium, 

uranium, thallium, and aluminum alloys. These activities have included large-scale metallurgy and 

fabrication of normal and fully enriched uranium. As of 1969, the CMR Bldg, except for its Wing 9, was 

used for laboratory work on small quantities of uranium and plutonium. Wing 9 contained hot cells for 

handling of irradiated uranium and plutonium (see Chapter 8). 

To gauge what impact LANL’s atmospheric uranium releases may have had in terms of human health 

risk, the NCRP Report No. 123 screening model was applied to airborne uranium source term information 

for 1972, for which LANL reported a relatively large release of 1,200 μCi of 234U/235U from TA-21. The 

1972 uranium release was screened against a criterion of a 1 in 100,000 added risk of fatal or non-fatal 

cancer, assuming a risk factor of 6% per sievert (Sv). This corresponds to a dose equivalent of 1.67×10-4

Sv (16.7 mrem). The exposed population selected was the residential area nearest the release point, 

apartments within the townsite at an estimated distance of 1,460 m. The pathways considered for the 

residential location were inhalation of contaminated air, plume immersion, irradiation from contaminated 

ground, and consumption of contaminated soil and vegetables. The calculation gave a screening value of 

1.7×10-6 Sv (0.17 mrem), much smaller than the screening criterion. The screening dose was also 

compared against screening criterion reduced by a factor of ten, as recommended by NCRP Report No. 

123 for Level II screening to account for uncertainties. This gives an adjusted screening value of 

1.67×10-5 Sv (1.67 mrem), still much larger than the screening dose. Thus, a significant human health 

risk (relative to the risk criterion) is not indicated for the uranium release reported for TA-21 for 1972. 

A screening evaluation was also performed for depleted uranium (DU). The effluent data for 1973 were 

used, with a release of 640 kg of DU from TA-3. On an activity basis, this equates to a release of 

2.11×105 μCi, assuming the material was 100% 238U (specific activity = 0.33 μCi g-1). The airborne DU 

release reported for TA-3 was assumed to have originated from the Sigma Complex. The nearest 
ES- 28 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary

residential area was determined to be the Western Area at a distance of about 1,040 m. The screening 

evaluation for the 1973 DU releases from TA-3 gave a screening value of 4.4×10-4 Sv (44 mrem). This 

value exceeds the unadjusted screening criterion, indicating further investigation into potential health 

risks is warranted. As with the evaluation for TA-21, the release value was used as reported by LANL 

and has not been adjusted in any way or independently verified. 

It seems counterintuitive that DU releases would screen so much higher than 235U, but that result reflects 

the large quantities of DU processed at Los Alamos over its history. DU was also expended in substantial 

quantities in dynamic experiments at firing sites such as TA-15 and TA-36. 

To follow-up on the result of the DU screening, the maximum average air concentration values reported 

by LANL’s ambient environmental air monitoring network for 1973 were evaluated in terms of the 

screening dose they represented. Assuming the measured air concentration values reflected 235U activity 

(the conservative choice), applying the NCRP Report No. 123 screening factor for 235U to the maximum 

offsite average for 1973 (in consistent units) gave a screening dose of 5.4×10-6 Sv (0.54 mrem). This is 

well below the screening criterion of 1.67×10-4 Sv even if the order of magnitude adjustment is applied to 

account for uncertainties. Treating the measured concentration as 238U would yield an even lower dose. 

The above evaluations do not paint a clear picture of the potential for health risks to Los Alamos residents 

from historical atmospheric releases of uranium. NCRP Report No. 123 screening evaluations have 

indicated enriched uranium releases were not significant in terms of potential risk relative to the limiting 

value selected, and showed releases of depleted uranium warranted further investigation. The ambient air 

monitoring data for 1973 did not suggest significant risk. None of these evaluations, however, consider 

releases from earlier in LANL’s history. Earlier releases may have been much larger than those from the 

1970s forward for which atmospheric effluent data have been conveniently summarized. 

Potential Doses to Members of the Public from the Trinity Test 

During World War II, two atomic weapon concepts were carried through to production at Los Alamos. 

The implosion-assembled plutonium-based design was by far the more complicated. A test of that device 

was considered necessary because of the “enormous step” from theory and experiments to production of a 

combat weapon and realization that, if the device failed over enemy territory, “the surprise factor would 

be lost and the enemy would be presented with a large amount of active material in recoverable form.” A 

“Fat Man” device was successfully tested at the Trinity Site near Socorro, New Mexico on 16 July 1945 

and another was dropped over Japan 24 d later. Seen by some as one of the most significant events in 

world history, the Trinity test fell within the scope of the LAHDRA investigation. Information about the 

Trinity test that was gathered by the LAHDRA team is summarized in Chapter 10 of this report. 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary ES-29 

To preserve the secrecy of the atomic bomb mission, residents of New Mexico were not warned before 

the 16 July 1945 Trinity blast or informed of residual health hazards afterward, and no residents were 

evacuated. Exposure rates on the day of the world’s first nuclear explosion measured up to 15 or 20 R h-1

in public areas northeast of ground zero at distances around 20 miles, near Hoot Owl Canyon. These 

critical measurements were made using instruments that were crude, ill suited to field use, and incapable 

of effectively measuring alpha contamination from about 4.8 kg of unfissioned plutonium that was 

dispersed. Vehicle shielding and contamination were recognized but not corrected for. The terrain and 

air flow patterns caused the highest levels of fallout to occur in areas in and around what became known 

to MED and Army personnel as “Hot Canyon.” The residential areas where highest exposure rates were 

measured on the day following the test were unknown to monitoring teams and were not even visited on 

16 July 1945, so exposure rates there on test day could have been even higher. Ranchers reported that 

fallout “snowed down” on local surfaces for days after the blast. A rancher whose house was 20 mi 

northeast of Trinity, reported that “for four or five days after [the blast], a white substance like flour 

settled on everything.” Because local ground water was not palatable to humans, many local residents 

collected rain water off their metal roofs into cisterns and used it for drinking water. It is documented that 

it rained the night after the test, so fresh fallout was likely consumed in collected water. Livestock were 

raised in the area, with most ranches having one or more dairy cows and a ranch near Hot Canyon 

maintaining a herd of 200 goats. 

Fallout from the world’s first nuclear test was measured in cardboard used by Kodak after they observed 

spotting on their film. The contamination was traced back to contaminated cardboard that had been 

caused by an Indiana paper mill’s use of river water that had been contaminated by the Trinity fallout. 

Airplanes equipped with filters followed the Trinity cloud across Kansas, Iowa, Indiana, upstate New 

York, New England, and out to sea. With modern monitoring methods, the contamination would likely 

have been detectable worldwide. 

All evaluations of public exposures from the Trinity blast that have been published to date have been 

incomplete in that they have not reflected the internal doses that were received by residents from intakes 

of airborne radioactivity and contaminated water and foods. Some unique characteristics of the Trinity 

event amplified the significance of those omissions. Because the Fat Man device was detonated so close 

to the ground, members of the public lived less than 20 mi downwind and were not relocated, terrain 

features and wind patterns caused “hot spots” of radioactive fallout, and lifestyles of local ranchers led to 

intakes of radioactivity via consumption of water, milk, and homegrown vegetables, it appears that 

internal radiation doses could have posed significant health risks for individuals exposed after the blast. 

The young health physics community had never faced the challenge of monitoring such an extensive 

environmental release of fission products, activation products, and unfissioned plutonium, and wartime 
ES- 30 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary

pressures to maintain secrecy and minimize legal claims led to decisions that would not likely have been 

made in later tests. Different standards of safety were applied to informed project workers than to 

uninformed members of the public. Project workers knew enough to evacuate areas when high exposure 

rates were measured, to wear respirators, to close their windows and breathe through a slice of bread, and 

to bury their contaminated food rather than eat it. But members of the public did not realize that changes 

in their behavior were prudent, and project staff did not call for evacuations or protective measures even 

though predetermined tolerances for exposure rate and projected total exposure had been exceeded. 

Too much remains undetermined about exposures from the Trinity test to put the event in perspective as a 

source of public radiation exposure or to defensibly address the extent to which people were harmed. 

Beyond omission of internal doses, all assessments released to date are based on monitoring data that 

have not been subjected to the processes used in modern dose reconstruction studies that include quality 

checking, cross-checking against other data sources, application of appropriate adjustments or corrections, 

and uncertainty analysis. 

Findings of the LAHDRA Project 

The LAHDRA project has significantly expanded the quantity of original documentation that is publicly 

available relevant to past operations at Los Alamos, activities by LANL personnel within New Mexico, 

and the potential for public health effects from past environmental releases. 

The gathered set of information is not perfect or complete. Some documents that were generated will 

never be found due to their loss or destruction, others are difficult to read because of their age and 

repeated photocopying, and most of the authors and participants from the periods of highest releases have 

passed away. In spite of these factors, the members of the LAHDRA study team believe that enough 

information exists to reconstruct public exposures from the most significant of LANL’s releases to a 

degree of certainty sufficient to allow health professionals to judge if significant elevations of health 

effects should be expected or measurable. For the latter part of the project, some documents containing 

certain categories of sensitive information were withheld from review by LAHDRA analysts. Because 

documents in these categories included nuclear weapon design details, foreign intelligence, and other 

types of information that are truly not relevant to studies of off-site releases or health effects, it does not 

appear that any information needed for dose reconstruction was withheld. And while text was redacted 

from many selected documents prior to public release, LAHDRA analysts had access to original and 

redacted copies and could verify that the redacted text did not contain information that would be needed 

for dose reconstruction. 

The information gathered by the LAHDRA team indicates that airborne releases to the environment from 

Los Alamos operations were significantly greater than has been officially reported or published to the 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary ES-31 

scientific community. The preliminary prioritization steps that have been performed within the LAHDRA 

project, while they have been quite simple, have provided information regarding the relative importance 

of past releases of airborne radionuclides, waterborne radionuclides, and chemicals. In general, it has 

been shown that early releases (1940s-1960s) were most important than those that followed, and that 

plutonium was the most important radionuclide in those early years. Airborne activation products from 

accelerator operations were most important after the mid-1970s, and gross alpha-emitting radioactivity 

was important for waterborne releases from the mid-1950s to the mid-1970s. Among chemicals, organic 

solvents as a class were likely most important, followed by TNT and uranium as a heavy metal. 

While prioritization analyses have provided relative rankings of contaminants within categories, the 

preliminary analyses described herein provided no estimates of concentrations to which members of the 

public were exposed, resulting intakes, or doses to members of the public that could be converted to 

estimated health risks or compared to toxicologic benchmarks or decision criteria. Priority Indices based 

on dilution volumes required to be in compliance with maximum allowable effluent concentrations do not 

reflect how uptake factors vary between radionuclides or the decay that occurs between release point and 

the location of potential public exposure. And because of the paucity of details regarding uses and 

releases of chemicals before the 1970s, the preliminary ranking process used for toxic chemicals did not 

incorporate estimates of the fractions of quantities of chemicals that were on-hand or used were available 

for release to the environment or were likely released. 

LAHDRA has been almost exclusively an information gathering effort. If estimates of historical 

exposures to members of the public are desired for the releases that have been identified and prioritized 

by the LAHDRA team, it will be necessary to delineate pathways of human exposure that were complete, 

to characterize environmental fate and transport, and to calculate doses and the subsequent health risks to 

groups who were exposed. Methods to perform these steps have been developed and applied for 

numerous other atomic weapons complex sites, but would have added dimensions to properly reflect the 

effects of the complex terrain in which LANL is set and to represent the transport of waterborne releases 

that often soak into dry stream beds before they travel very far, to be transported to a large part by 

occasional high flow events that wash contaminants toward the Rio Grande. 

A number of historical operations have been identified by LAHDRA analysts as areas that might have 

been particularly important in terms of off-site exposures. In addition, critical information gaps have 

been identified in several areas. 

• Early airborne releases of plutonium. Plutonium was processed in crude facilities in D Building 

during World War II, and many roof-top vents were unfiltered and unmonitored. After DP West Site 

took over production late in 1945, there was some filtering of releases, but poor monitoring practices 
ES- 32 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary

caused releases to be underestimated. DP West releases for 1948-1955 alone were over 100-times the 

total reported by the Lab for operations before 1973. A screening assessment of public exposures 

from peak releases from DP West Site in 1949 showed that airborne plutonium releases warrant 

further evaluation. 

• Airborne beryllium releases. Los Alamos used significant quantities of beryllium before the health 

hazards of the material were fully appreciated, and it was processed very close to residential areas. 

Preliminary screening indicated that early beryllium processing could have resulted in concentrations 

in residential areas that exceeded worker exposure limits, the USEPA reference concentration, and the 

National Emission Standard for beryllium. 

• Public exposures from the Trinity test. Residents of New Mexico were not warned before the 1945 

Trinity blast or informed of health hazards afterward, and no residents were evacuated. Exposure 

rates in public areas from the world’s first nuclear explosion were measured at levels 10,000-times 

higher than currently allowed. Residents reported that fallout “snowed down” for days after the blast, 

most had dairy cows, and most collected rain water off their roofs for drinking. All assessments of 

doses from the Trinity test issued to date have been incomplete in that they have not addressed 

internal doses received after intakes of radioactivity through inhalation or consumption of 

contaminated water or food products. 

• Airborne uranium releases. LANL has used uranium since its beginnings in enrichments ranging 

from depleted to highly enriched. It has been machined and fabricated into weapon and reactor 

components and large quantities have been expended in explosive testing. Preliminary screening 

assessments indicate that enriched uranium releases do not warrant high priority in terms of potential 

health risk, but show that releases of depleted uranium warrant further investigation. None of these 

evaluations, however, consider releases from LANL’s early operations. Early releases could have 

been much larger than those from the 1970s forward, for which effluent data have been summarized. 

Further investigation is needed before a conclusive assessment can be made of potential health risks 

from LANL’s airborne uranium releases. 

• Tritium releases before 1967. Los Alamos used tritium as early as 1944, and received it in 

increasing quantities in the decades that followed for use at ten or more areas of the Lab. In spite of 

this, LANL compilations of effluent data include no tritium releases before 1967. LAHDRA team 

members located scattered documents that describe numerous episodic releases within the 22-y period 

of tritium usage for which official reports of LANL releases include no data for the radionuclide. 

These documents call into question the release estimates reported by LANL for 1967 forward and 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary ES-33 

indicate that releases before 1967 constitute a data gap that must be addressed if the health 

significance of LANL tritium releases is to be evaluated. 

Based upon the findings of the LAHDRA project, CDC and other interested parties will judge if the 

available information indicates that past releases of any materials could have been sufficiently high that 

detailed investigation of past releases and public exposures is warranted, and if it appears that sufficient 

information exists to support detailed investigation if the requisite funding could be made available. 

Potential further investigations that could be undertaken for one or more contaminants of highest priority 

could range from screening level assessments of potential public exposures to more rigorous exposure 

assessments like those that have been conducted for other MED/AEC/DOE sites and have become known 

as dose reconstructions. Unlike the prioritization analyses performed to date, these assessments, if they 

are undertaken, would likely incorporate modeling of environmental transport, exposure pathway 

analysis, and reflection of the uncertainties and variability associated with input data, assumptions, and 

models so that the ranges of exposures received by likely members of the public can be specified at a 

stated level of confidence. Assessments of that type are often performed in an iterative fashion, with 

uncertainty analyses focusing research on components of the assessment that are contributing most to the 

overall uncertainty of results. Further refinement can be directed to those elements, and the process 

repeated until the uncertainty of results is acceptable or cannot be further reduced. 
ES- 34 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Executive Summary

This page intentionally left blank. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 1 1-1 

Chapter 1: Introduction to the LAHDRA Project 

The Los Alamos Historical Document Retrieval and Assessment (LAHDRA) project began in early 1999. 

It is being conducted by the Centers for Disease Control and Prevention (CDC), National Center for 

Environmental Health. Much of the work of the project was conducted by contractors to CDC, namely 

ChemRisk Inc. and subcontractors Shonka Research Associates Inc., ENSR Corporation, and Advanced 

Technologies and Laboratories International, Inc. 

Shortly after the Manhattan Engineer District (MED) was formed in 1942 to develop the world’s first 

atomic bombs, construction of major research and production facilities began near secret areas that are 

now known as Oak Ridge, Tennessee; Los Alamos, New Mexico; and Richland, Washington. After the 

Atomic Energy Commission (AEC) was established in 1947, a second wave of construction added 

facilities in Idaho, South Carolina, and Colorado. Starting with one uranium bomb and approximately 

four plutonium bombs produced at Los Alamos in 1945 (Wahl 1947) the nation’s nuclear warhead 

stockpile grew to a total explosive yield equivalent to approximately 20 billion tons of TNT by 1959 

(USDOE 1997). Because facilities of the nuclear weapons complex used a wide variety of toxic materials 

and operated for decades behind a “cloak of secrecy,” public concern about potential health risks from 

their operations grew as more was learned about past activities and events. 

Between 1979 and 1992, retrospective evaluations of historical releases and potential health effects were 

initiated for each of the major early MED/AEC sites except Los Alamos (Church et al. 1990, Ripple et al. 

1994, Shipler et al. 1996, HAP/CDPHE 1999, McGavran and Case 1999, Devine et al. 2000, Meyer et al. 

2002, Widner and Flack 2002, ATL International 2006). Because the first several assessments were 

carried out by the U.S. Department of Energy (DOE) or contractors closely associated with nuclear 

weapon production efforts, and many documents upon which these studies were based were classified or 

considered proprietary, a general distrust of the results of the studies developed (National Research 

Council 2006). Under a Memorandum of Understanding signed with DOE in December 1990 and 

updated in 1996 and 2000, the Department of Health and Human Services (HHS) accepted the 

responsibility for conducting analytic epidemiologic investigations of residents of communities in the 

vicinity of DOE facilities (National Research Council 2006). HHS delegated program responsibility to 

the Centers for Disease Control and Prevention (CDC). In response to requests from elected officials in 

New Mexico, CDC began exploratory investigations at Los Alamos National Laboratory (LANL) in 

1994. These investigations indicated that off-site releases had occurred and large repositories of records 

existed at the facility, many of which were classified. CDC noted major uncertainties at the time 

regarding the number of records requiring review at LANL and the extent to which they could be 
1-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 1 

effectively reviewed by outside investigators. CDC awarded a contract that allowed work to begin on the 

Los Alamos Historical Document Retrieval and Assessment (LAHDRA) project early in 1999, with a 

focus on identifying the information that is available concerning past releases of radionuclides and 

chemicals from the government complex at Los Alamos. 

The stated goals of the LAHDRA project were to: 

1) retrieve historical documents and evaluate their usefulness for off-site dose assessment, 

2) declassify (as necessary) relevant documents and release them to the public, 

3) enter relevant documents into a project information database, and 

4) develop a prioritized list of contaminant releases from the LANL site. 

The primary purpose of the LAHDRA project is to identify the information that is available concerning 

past releases of radionuclides and chemicals from the government complex at Los Alamos, New Mexico. 

Sited in northern New Mexico and owned by the Department of Energy, the Los Alamos facilities were 

managed by the University of California from 1943, when “Project Y” was born as part of the Manhattan 

Project to create the first atomic weapons, until a new team was put in a management role within the last 

several years. Project Y became known as Los Alamos Laboratory, and its name changed to Los Alamos 

Scientific Laboratory in 1947 and then to Los Alamos National Laboratory in 1981. For sake of 

simplicity in this document, we will in some cases refer to LANL for all time periods. LANL’s 

responsibilities have expanded since the wartime years, to include thermonuclear weapon design, high 

explosives and ordnance development and testing, weapons safety, nuclear reactor research, waste 

disposal or incineration, chemistry, criticality experimentation, tritium handling, biophysics, and 

radiobiology. 

LANL operations have not proceeded without health hazards or environmental impacts. Approximately 

30 people have been killed in incidents including criticality experiments and accidents with high 

explosives. Significant quantities of plutonium, uranium, and a wide variety of other toxic substances 

have been processed and released to the environment in quantities that in some cases are not well known. 

The project team investigated the materials used throughout LANL’s history of operations to identify and 

prioritize releases in terms of their apparent relative importance from the standpoint of potential off-site 

health effects. Based on the project’s findings, CDC will work with stakeholders to determine if moredetailed assessments of past releases are warranted. Should additional investigations be warranted, they 

might be in the form of screening-level evaluations, or could progress to detailed dose reconstruction for 

those releases of highest priority. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 1 1-3 

In more specific terms, CDC’s model of dose reconstruction involves a process that can be broken up into 

as many as five phases: 

• Retrieval and Assessment of Data 

• Initial Source Term Development and Pathway Analysis 

• Screening Dose and Exposure Calculations 

• Development of Methods for Assessing Environmental Doses 

• Calculation of Environmental Exposures, Doses, and Risks 

CDC has completed various stages of this process at INEEL, Savannah River, and Los Alamos. Various 

stages of the process may overlap in time, and stages may be performed iteratively. All stages may not be 

necessary at all sites. Each stage involves CDC staff, contractors, and the public. While CDC’s 

LAHDRA represented the information-gathering phase, some work advanced into prioritization of 

releases and simple, screening-level assessment of potential exposures for several operations that 

appeared to have been particularly important. 

The Products of the LAHDRA Project 

The products of the LAHDRA project include: 

• This Draft Final Report 

• A database that contains bibliographic information and summaries of the content of relevant 

documents that were located by the project team. 

• Sets of copies of the most relevant documents, to be made available by DOE in a reading room in 

Albuquerque. 

• A collection of electronic document images, as Portable Document Format (PDF) files, of all 

documents for which paper copies or electronic files were obtained. 

• A chronology of incidents and off-normal events identified in review of reports prepared by Los 

Alamos’ Health Division. 

The Project Information Database 

A Microsoft® Access database was created to store the information reviewed and collected during this 

project. The CDC defined the basic database structure and values of many of the fields at the onset of the 

project. A user-friendly front-end was developed for use by the project analysts for reviewing the 

information collected. The database includes a form created for entering the information from the 

document summary forms (DSFs) filled out by document analysts in the field, and also a form to perform 
1-4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 1 

searches on all the information that has been entered. In 

the search form, users can search on every field on the 

DSF. 

As each DSF was entered into the project database, it 

was assigned a unique sequential Repository Number. 

This designation was used to track the information 

throughout the remainder of the project. Most of the 

reference citations in this report include repository 

numbers, often abbreviated “Repos. No.” Note that a 

repository number may represent a number of related, 

individual documents. 

The project database has been made available to the public by placing it in three regional libraries: the 

Zimmerman Library at the University of New Mexico in Albuquerque, the Mesa Public Library in Los 

Alamos, and the Northern New Mexico Community College library in Española. 

The project repository contains paper copies of documents selected as relevant by the project team and 

released by LANL (see Fig. 1-1). This repository currently contains over 264,000 pages of documents. 

These documents, or sets of documents, are arranged sequentially under 8,372 Repository Numbers. A 

duplicate set of the project’s document repository is maintained at the Zimmerman Library at the 

University of New Mexico in Albuquerque. This location was selected by the U.S. Department of Energy 

as the official Public Reading Room for this Project. The Zimmerman Library is located on the 

University of New Mexico's (UNM's) main campus. The library’s Government Information Department is 

a regional depository for government documents. Documents can be requested at the information desk, 

and photocopies can be made at a nominal cost using copy machines in the immediate area. 

Document Images 

As the number of paper copies grew and scanning technology matured, it was decided that a better way 

to preserve and present the reference material being collected by the LAHDRA team would be as scanned 

images. Ultimately, all of the information was scanned in as PDF files and an Adobe Acrobat full text 

search capability was developed. A controlled-access, Internet-based application called DocSleuth was 

developed by the LAHDRA team to make the information collected for the project available to the project 

team, libraries, and trusted researchers. As described in Chapter 3, DocSleuth offers capabilities for 

filtered, full-text searching of bibliographic information and scanned text from collected documents. 

Fig. 1-1. One of several sets of copies of 

documents selected by the LAHDRA team
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 1 1-5 

Chronology of Incidents and Off-Normal Events 

As described in Chapter 13, progress reports issues by the Los Alamos Health Division (H Division) are 

particularly useful sources of information about operations, releases, episodic events, and accidents 

involving radionuclides and other toxic materials. The LAHDRA team made a concerted effort to obtain 

as many H-Division progress reports as possible. The project information database currently contains 

summary data for hundreds of Health Group and H-Division progress reports. At present, these reports 

cover a date range from 1943 to 1990. Most of the reports cover a one month period, though there are 

also annual reports and, in later years, quarterly reports. The monthly reports were discontinued around 

early 1965 in favor of quarterly reports. 

A chronology of episodic or off-normal events described in these reports will be a valuable resource for 

depicting historical release pathways, particularly in describing mechanisms for fugitive emissions and 

other unmonitored pathways that might otherwise go unaccounted for. And for hazardous chemicals, the 

anecdotal information contained in many H-Division reports makes up a large part of what we know 

about historical usage and actual or potential releases. The latest available version of a chronology of 

episodic or off-normal events, based on reports that have been reviewed as of the date of release of this 

report, is presented in Chapter 16. Each event is described briefly, and Repository Number and page 

number references are provided. 

The H-Division progress reports were compiled by the Division Leader and contained information 

submitted by the leaders of the individual groups that made up the Health Division at a given time. While 

the material they provide is largely of a summary nature, the reports are nonetheless detailed and provide 

an array of information. Collectively, the reports provide a chronology of laboratory operations with an 

emphasis on experience with hazardous materials. They cover the breadth of what are now known as 

health physics and industrial hygiene, and provide information in a number of areas of interest to the 

LAHDRA Project, including: 

• materials (contaminants) of concern (radionuclides, chemicals, and explosives) 

• instrumentation issues 

• monitoring/sampling of waste streams/effluents 

• monitoring of special (short-duration) programs and experiments 

• unmonitored releases and fugitive emissions 

• environmental monitoring 

• episodic events and incidents involving spread of materials to private property or residences 
1-6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 1 

• facility operations (including ventilation system issues, modifications, etc.) 

• waste disposal practices and issues 

Of particular note is the fact the reports provide information on various chemicals and compounds that 

were being utilized at various times, where the materials were being used, and what they were being used 

for. While this information is largely qualitative, it still provides a valuable resource for prioritization of 

non-radioactive hazardous materials for time periods for which such information is scarce. The reports 

also yield valuable information regarding sources of unmonitored releases and fugitive emissions that are 

always difficult to evaluate in retrospective assessments. 

 Beyond the specific information contained in the individual H-division progress reports, the continuity of 

the information they provide collectively (the monthly reports in particular) gives insight into chronic and 

recurring concerns that may not have been apparent at the time. Applied retrospectively, this information 

can be used to advance both the document search tasks and the evaluation of information obtained relative 

to off-site releases and potential effects. 

The Contents of this Report 

This report represents a summary of information that has been obtained by the LAHDRA project team 

regarding: 

• historical operations at Los Alamos, 

• the materials that were used, 

• the materials that were likely released off site, 

• development of residential areas around Los Alamos, and 

• the relative importance of identified releases in terms of potential health risks. 

The information in this report was obtained from records reviewed at Los Alamos by the project team, 

information from several off-site collections, some books and reports that are publicly available, and 

some interviews with past and current Los Alamos workers and members of the public. Preparation of 

LAHDRA project reports has been an open and iterative process. Interim reports have been issued at 

approximate one-year intervals so that interested parties could see the types of information the LAHDRA 

team was finding, be introduced to the approaches being taken to interpret the information that was found, 

and offer comments and criticism as to how the information gathering process and the report could be 

improved as work progressed. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 1 1-7 

Based on the findings of the ongoing information 

gathering process, which are summarized in this report and 

evidenced in the project information database, CDC will 

work with stake holders to evaluate whether historical 

releases for radionuclides or other toxic materials from Los 

Alamos operations warrant more detailed evaluation. 

References 

ATL International. Risk-based screening of radionuclide releases from the Savannah River Site. 

Germantown, MD: Advanced Technologies and Laboratories International, Inc.; 2006. 

Church BW, Wheeler DL, Campbell CM, Nutley RV, Anspaugh LR. Overview of the Department of 

Energy's off-site radiation exposure review project (ORERP). Health Phys 59: 503-10; 1990. 

Devine OJ, Qualters JR, Morrissey JL, Wall PA. Fernald risk assessment project Phase II screening level 

estimates of the lifetime risk of developing kidney cancer, female breast cancer, bone cancer, 

leukemia resulting from the maximum estimated exposure to radioactive materials released from 

the former Feed Materials Production Center (FMPC). Final report. Atlanta, GA: Centers for 

Disease Control and Prevention, National Center for Environmental Health; 2000. 

HAP/CDPHE. Summary of findings, historical public exposures studies on Rocky Flats. Denver, CO: 

Health Advisory Panel and the Colorado Department of Public Health and Environment; 1999. 

McGavran PD, Case MJ. Final report: The feasibility of performing a chemical dose reconstruction study 

at the INEEL. Neeses, SC: Risk Assessment Corporation; 1999. 

Meyer KR, Mohler HJ, Aanenson JW. Final report: Identification and prioritization of radionuclide 

releases from the Idaho National Engineering and Environmental Laboratory. Risk Assessment 

Corporation. 2002. 

National Research Council. Review of the Worker and Public Health Activities Program administered by 

the Department of Energy and the Department of Health and Human Services. Washington, DC: 

The National Academies Press; 2006. 

Fig. 1-2. An early photo of the main gate 

into Los Alamos 
1-8 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 1 

Ripple SR, Brorby GP, DiTommaso D, Ting D, Buddenbaum JE, Lee KH, Widner TE. Project Task 8 

report: Dose assessment for historical contaminant releases from Rocky Flats. Alameda, CA: 

ChemRisk, a Service of McLaren/Hart, Inc.; 1994. 

Shipler DB, Napier BA, Farris WT, Freshley MD. Hanford Environmental Dose Reconstruction project– 

an overview. Health Phys 71: 532-44; 1996. 

USDOE. Linking legacies - Connecting the cold war nuclear weapons production processes to their 

environmental consequences. Washington, DC: U.S. Department of Energy; DOE/EM-0319; 

1997. 

Wahl AC. Chemical purification of plutonium, Chapter 3 of Los Alamos Technical Series, Volume 8, 

Chemistry of uranium and plutonium. Los Alamos, NM: Los Alamos Scientific Laboratory; LA1016; 1947. Repos. No. 3084. 

Widner TE, Flack SM. Dose Reconstruction for Radionuclides and Chemicals: Case Study Involving 

Federal Facilities at Oak Ridge, Tennessee. Chapter 13. Human and ecological risk assessment 

theory and practice: 735-869; 2002. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 2 2-1

Chapter 2: Overview of Historical Operations 

 at Los Alamos 

When the Los Alamos facility was initiated, it had a single mission— perfection of the design and 

manufacture of the first atomic bombs. The initial plan for the first atomic weapon was for a “gun 

assembled” device that would use slow-burning propellants, as shown in concept in Fig. 2-1 (LANL 

1983). Gun-assembled weapons may be designed on the principle of using a propellant to drive a mass of 

fissile material at a target of the same material to attain a supercritical assembly. To develop and build 

gun-assembled weapons, Los Alamos personnel initially experimented with use of enriched uranium 

(

235U) and plutonium as the fissionable material. Other materials that were needed included the explosive 

propellant, a detonator to set off that propellant, and precision machined housings to support assembly of 

the critical mass in the necessary configuration within the required time frame. Part of the housings were 

cases of heavy metal (such as uranium), called “tampers,” that confined the explosion, reflected some 

neutrons that would otherwise escape, and thereby decreased the “critical mass” of fissile material 

required to give rise to an atomic explosion (Serber et al., 1992). 

Subcritical Masses

Explosive 

Propellant

Supercritical Mass

BEFORE FIRING IMMEDIATELY 

AFTER FIRING

THEN EXPLODES

Fig. 2-1. Concepts of a gun-assembled atomic weapon

Early development work centered on potential use of 235U or 239Pu in gun-assembled devices. Top 

priority was given to development of a plutonium-projectile gun device, with posed more problems than 

the uranium design due to tighter purity specifications and the need for a faster assembly velocity. In July 

1944, it was found that the plutonium that was being received at Los Alamos would not work in gunassembled weapons due to the presence of more of the 240Pu isotope than expected amidst the desired 

239Pu. The spontaneous neutron emission rate from that plutonium was several hundred times greater than 

allowable. As a result, while research on the “certain to work” uranium gun device continued, 

development of a plutonium device shifted to an implosion-assembled design. A second design was 
2-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 2 

needed because the delivery rate for enriched uranium would only support production of a single uranium 

weapon within the imposed schedule, and it was thought that more than one weapon would be necessary. 

Implosion-assembled weapons may be designed on the principle of squeezing (compressing) the fissile 

material to super-criticality by detonation of a high-explosive implosion system. The implosion type 

bomb is depicted conceptually in Fig. 2-2 (LANL 1983). 

Chemical 

Explosive

Subcritical Mass

BEFORE FIRING IMMEDIATELY 

AFTER FIRING

THEN EXPLODES

Compressed 

Supercritical Mass

Implosion

Fig. 2-2. Concepts of the implosion-assembled atomic weapon

To develop and build implosion-assembled devices, much experimentation had to be done with getting 

chemical high explosives to precisely assemble something with great symmetry, in contrast to their 

typical uses in blowing things up. Work on high explosives centered on achieving precise timing of 

detonations at the surface of the explosive and use of “lenses” of a different explosive to focus the 

resulting shock waves on the metal sphere in the center of the device (Serber et al. 1992). In addition to 

fissionable material, high explosives, detonators, and tamper material, work on implosion-assembled 

devices included development of “initiators” that acted as strong sources of neutrons at the precise time 

that the supercritical masses came into position, to make sure that the fission chain reaction started when 

it had to. These initiators used materials including radium, beryllium, and polonium (Serber et al. 1992). 

With the successful demonstration of fission devices, scientists were able to achieve the high 

temperatures necessary to bring about fusion of hydrogen nuclei for use in the “Super” bomb that had 

been studied for years as a theoretical possibility. Viewed by some as Los Alamos’ second historic 

mission, development of thermonuclear or “hydrogen” devices led to the first full-scale testing in the 

Mike shot in the Pacific in late 1952. Thermonuclear devices rely on a two-staged process, in which 

energy from a fission “primary” is contained and used to trigger a fusion or fusion-fission reaction in a 

physically-separate “secondary” portion of the device. These concepts of a staged thermonuclear weapon 

are shown in Fig. 2-3 (LANL, 1983). 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 2 2-3

Materials needed for thermonuclear devices included many of those needed for a gun-assembled or 

implosion-assembled device, plus fuel for the fusion reaction. The first thermonuclear devices used liquid 

fuel, such as deuterium, that required significant developments in cryogenics in order to keep the fuel 

below its boiling point of –250 Celsius. Later devices used lithium deuteride fuel, in solid form, which 

“breeds” tritium when exposed to neutrons. 

Reentry Body

Primary Secondary

Radiation Case

Fig. 2-3. Concepts of a staged nuclear weapon

After World War II, Los Alamos scientists and engineers were involved in development and testing of 

numerous designs of nuclear devices that were more and more powerful, compact, reliable, dependably 

deployable in the field, and contained in a variety of delivery vehicles suited to various combat objectives. 

They were involved in many tests of nuclear devices within the continental United States, in the Pacific, 

and in Alaska, including some that were part of the Plowshare program that aimed to develop peaceful 

applications for nuclear explosives. 

Los Alamos was the lead site for U.S. nuclear component fabrication until 1949, when the Hanford 

Plutonium Finishing Plant in Washington began making “pits,” the central cores of the primary stages of 

nuclear devices (USDOE 1997). In 1952, the Rocky Flats Plant near Denver began making pit 

components. After 1949, Los Alamos was a backup production facility and designed, developed, and 

fabricated nuclear components for test devices. Pit production stopped at the Hanford facility in 1965, 

and the Rocky Flats Plant ceased operations in 1989. From time to time, Los Alamos was called upon to 

perform special functions in its backup role. For example, because of an accident at the Hanford 

Plutonium Finishing Plant in 1984, plutonium was sent in oxide form to Los Alamos for conversion to 

metal (USDOE 1997). Special activity at Los Alamos might also have occurred after major fires in 

plutonium facilities at Rocky Flats in 1957 and 1969. 
2-4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 2 

Operations, facilities, and capabilities that were needed to support development and production of the 

various types of nuclear devices expanded in many cases to support other missions after World War II. 

Programs in chemistry, metallurgy, and low temperature physics expanded into nonmilitary development 

and fundamental research. For example, Los Alamos developed one of the largest experimental machine 

shops in the country. The Health Division grew significantly and expanded into many areas of health 

physics, industrial hygiene, medicine, safety, and biomedical research regarding people and radiation. 

Early reactors that were built to confirm critical masses for fissionable materials and to study properties of 

fission and the behavior of resulting neutrons, were the forerunners of a variety of reactors that were 

designed and in some cases built and operated at Los Alamos. While some of these reactors served as 

sources of neutrons for various types of nuclear research or for materials testing, other designs were 

pursued for potential applications in power generation and propulsion of nuclear rockets into deep space. 

Some of the first significant steps towards controlled nuclear fusion as a power source were taken at Los 

Alamos, and the plasma thermocouple program explored methods for direct conversion of fission energy 

to electricity for potential application in propulsion of spacecraft. 

 Operations at Los Alamos have taken place in land divisions called Technical Areas, or TAs. Table 2-1 

contains a listing of these Technical Areas, including some that have been abandoned, some that were 

combined with other TAs, and some that were cancelled before they ever became operational. Table 2-1 

also contains listings of some of the various radioactive materials that are documented to have been used 

at each technical area, based on information reviewed to date. A similar tabulation of chemicals used at 

each technical area has not yet been compiled. 

Figures 2-4 and 2-5 show the location of LANL within New Mexico and the layout of the modern-day 

Technical Areas, while Fig. 2-6 presents a timeline of some selected operations and activities at (or 

related to) Los Alamos. 

References 

LANL 1983. “Nuclear Weapon Illustrations”, Classification Bulletin No. 9. August. 

Serber et al. 1992. “The Los Alamos Primer– The First Lectures on How to Build An Atomic Bomb.” 

Contains an annotated version of report LA-1, “The Los Alamos Primer” (1943). University of California 

Press, Berkeley. 

USDOE 1997. “Linking Legacies– Connecting the Cold War Nuclear Weapons Production Processes To 

Their Environmental Consequences.” DOE/EM-0319. U.S. Department of Energy, Washington, DC. 

January. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 2 2-5

Table 2-1. Los Alamos Technical Areas past and present 

TA Name and Description Materials Involveda

TA-0 Los Alamos Townsite: leased space in Los Alamos and White Rock for training, 

support, unclassified research and development, community outreach, museum 

None 

TA-1 Original Main Technical Area (inactive): 1943-65 active; turned over to Los 

Alamos County or private interest in 1966; all contamination removed by 1975 

EU, DU, 238,239Pu, 241Am, 210Po, 140Ba, 140La 

TA-2 a.k.a.c Omega Site: Early critical assembly experiments. Water Boilers (1944-

1974); Pu Fast Reactor, a.k.a. Clementine (1946–1950); and Omega West Reactor 

(1956-1992); reactors used for critical experiments up until 1946 when experiments 

were moved to TA-18. Omega Site reactors operations were then centered around 

neutron experiments and isotope production 

235U; 239Pu; 131I; 88Rb; 137Cs; 131Xe; 125I; 41Ar, 3

H 

TA-3 Core Area (a.k.a. South Mesa Site; active 1949 to present): detonator 

manufacturing, metallurgy burn pit, firing sites from 1943-49. Listed below are 

brief descriptions of key TA-3 operations. 

238,239Pu, 235,238U, DU, 

NU, 210Po 

TA-3-29 Chemistry and Metallurgy Research: actinide chemistry and metallurgy research 

since 1952 to present 

239Pu; 238Pu; 235U; 238U, 

DU 

TA-3-66 Sigma: materials fabrication since 1958; also –141 Rolling Mill, -35 Press Bldg, 

-159 thorium storage 

235U; DU 

TA-3- 

1698 

Materials Science Laboratory: processing, mechanical research DU 

TA-3- 

39,102 

Machine shops: since 1953; Be in Bldg 39, DU in Bldg 102 DU 

TA-4 Alpha Site: firing site until 1956; Material Disposal Area C DU 

TA-5 Beta Site: former firing site used extensively in 1945 DU 

TA-6 Two-Mile Mesa Site: mostly undeveloped; detonator manufacturing and testing 

1944-50 

DU 

TA-7 Gomez Ranch Site: former firing site used from 1944-47 for small explosive 

experiments with short-lived radionuclides 

DU; unknown 

TA-8 GT Site (a.k.a. Anchor Site West): gun firing sites 1943-45; explosives processing 

1945-50; nondestructive X-ray testing 1950-present 

239Pu; 238Pu; 235U; DU; 60Co; 192Ir; 137Cs; X-rays 

TA-9 Anchor Site East (a.k.a. Anchor Ranch): firing areas; explosives research (active) DU; 3H 

TA-10 Bayo Canyon: Radioactive lanthanum test shots 1944-61; Radioactive lanthanum 

radiochemistry 1944-50; site removed in 1963 

90Sr; DU; NU; 140La 

TA-11 K Site (active): implosion studies; later drop and vibration tests, dates unknown at 

this time 

DU; 226Ra, betatron 

TA-12 L Site: explosives testing (1945-46); abandoned in mid-1950s DU 

TA-13 P Site: X-ray studies of explosives; later incorporated with TA-16, status unknown X-rays, DU, 210Po 

TA-14 Q Site (active): explosives testing 1944-present DU 

TA-15 R Site: explosives testing; eight inactive firing sites (A-H, R44, R45); Pulsed 

High-Energy Radiation Machine Emitting X-Rays (PHERMEX) 1962-present; 

Dual-Axis Radiographic Hydrodynamics Test (DARHT) Facility 

239Pu; DU; 3

H; X-rays 

TA-16 S Site (active): former explosives casting/machining operations; burning ground; 

Weapons Engineering Tritium Facility. Began in the 1950s 

239Pu; DU; 3

H; X-rays 

TA-17 X Site (canceled) None 

TA-18 Pajarito Laboratory: criticality testing 1946-present; Rover 1955-73; Hydro 

assembly 1957 

235U; 239Pu; 240Pu; 233U; 

MFP; 131I; polonium; 

neutron 

TA-19 East Gate Laboratory: released to U.S. Atomic Energy Commission in 1962 None 
2-6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 2 

Table 2-1: Los Alamos Technical Areas Past and Present (Continued) 

TA Name and Description Materials Involveda

TA-20 Sandia Canyon Site: former firing site abandoned in 1957 DU 

TA-21 DP Site: former plutonium operations (DP West); uranium/polonium operations (DP 

East); Material Disposal Areas A,B,T,U,V; Tritium Systems Test Assembly, 

Tritium Science and Fabrication Facility (1945 to 1978) 

239Pu; 238Pu; 240Pu; 241Pu; 241Am; 235U; 238U; 210Po; 227Ac; 3

H 

TA-22 TD (Trap Door) Site: detonator development; shops; disposal pits DU 

TA-23 NU Site: reduced firing load at TA-9 1945-50 Unknown 

TA-24 T Site: X-ray studies of explosives; later incorporated with TA-16 X-rays, DU 

TA-25 V Site: explosives assembly; later incorporated with TA-16 DU 

TA-26 D Site: storage vault and guard building 1946-48; removed in 1966 3H, 235U; 233U 

TA-27 Gamma Site: plutonium gun assembly 1945-47 239Pu, DU, thorium 

TA-28 Magazine Area A (active): firing site 1979; explosives storage area DU 

TA-29 Magazine Area B: explosives storage area; abandoned in 1957 DU 

TA-30 Electronics Test Area: electronics testing 1945-48 Unknown 

TA-31 East Receiving Yard: 1948-54 warehouses W of airport; removed 1954 Unknown 

TA-32 Medical Research Laboratory: bio-research facility; 1943-54; removed in 1954; 

incinerator use included 

Unknown 

TA-33 HP (Hot Point) Site: 1948-56 shaft experiments; High Pressure Tritium Laboratory 

1970s; Material Disposal Areas D, E, K 

3

H 

TA-34 New Laboratory Warehouse Area (canceled) None 

TA-35 Ten Site: Radioactive lanthanum 1951-63; Los Alamos Power Reactor Experiment 

(LAPRE) I/II 1950s; Los Alamos Molten Plutonium Reactor Experiment 

(LAMPRE) I 1960s; laser fusion research 1974 

3

H; 90Sr; 140Ba; 140La; 235U; DU; 237Np; Pu; Po; 

Co; VFP 

TA-36 Kappa Site: replaced TAs-9, 23, 12 in 1950; four active firing sites; nonnuclear 

ordnance and armor 

DU 

TA-37 Magazine Area C (active): explosives storage area DU 

TA-38 Monterey Site (canceled) None 

TA-39 Ancho Canyon Site: five firing points; incinerator 1955-60; photographic study of 

the behavior of nonnuclear weapons 

NU; DU; thorium 

TA-40 DF (Detonator Firing) Site: six firing points; detonator development 3H 

TA-41 W (Weapons Group WX) Site: engineering of nuclear components; fabrication of 

test materials 

3

H; plutonium; uranium; 

americium 

TA-42 Incinerator Site: for low-level Pu contaminated waste; abandoned 1970 All 

TA-43 Health Research Laboratory: biological research 1953-70; replaced TA-32 All 

TA-44 Los Angeles Shop: experimental machine shop in Los Angeles, CA 1949-58; 

abandoned in 1958 

Unknown 

TA-45 Radioactive Liquid Waste Treatment Plant (inactive): removed majority of 

plutonium before discharge to Acid Canyon 

238/239Pu, 235/238U 

TA-46 WA Site: Rover batteries 1950-74; U isotope separation 1976-early 1980s; 

photochemistry research; lasers 

235U, 238U thorium 

TA-47 BR Site (Bruns Railhead): shipped materials via a railhead near Bruns Hospital in 

Santa Fe, 1943-58; abandoned in 1958 

DU; unknown 

TA-48 Radiochemistry Site: actinide chemistry and hot cell isotope production, area used 

for analyzing samples from weapon test shots, 1950s to present 

U; TRU; MAP; MFP 

TA-49 Frijoles Mesa Site: underground hydronuclear experiments 1960-61; now 

Hazardous Devices Team Training 

3

H; plutonium; uranium 

TA-50 Waste Management Site: treated liquid wastes before discharge to Mortandad 

Canyon; replaced TA-45,-35; controlled air incinerator 1976 

All 

TA-51 Environmental Research Site: animal exposure facility 1962; now studies of impact 

of waste and waste storage on the environment 

60Co, strontium 

TA-52 Reactor Development: Ultra-High Temperature Reactor Experiment (UHTREX) 235U; 238Pu; 3H; VFP; Kr; 

Xe 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 2 2-7

Table 2-1: Los Alamos Technical Areas Past and Present (Continued) 

TA Name and Description Radioactive Materials 

Involveda

TA-53 Los Alamos Neutron Science Center (LANSCE) 3H; 41Ar; 7Be; 11C; 13N; 15O; U 

TA-54 Waste Disposal Site: solid wastes; Materials Disposal Areas G, H, J, L All 

TA-55 Plutonium Facility Site (active): replaced TA-21; SNM storage, 1978 to present 239Pu; 3H 

TA-56 Subterrene Basalt Site: melting basalt with electrically heated penetrator; 

abandoned in 1976 

Unknown 

TA-57 Fenton Hill Site: Hot Dry Rock geothermal project (inactive) Unknown 

TA-58 Two-Mile North Site: experimental sciences for TA-3 programs Unknown 

TA-59 Occupational Health Site: Office of Environment, Safety, and Health offices, 

emergency management 

None 

TA-60 Sigma Mesa: Test Fabrication Facility and Rack Assembly; Alignment Complex Unknown 

TA-61 East Jemez Road: physical support and sanitary landfill Unknown 

TA-62 Northwest Site: reserved for experiments, research, buffer zones Unknown 

TA-63 Pajarito Service Area: environmental and waste management functions Unknown 

TA-64 Central Guard Facility, Hazardous Materials Response Team None 

TA-65 Not currently active or never assigned None 

TA-66 Central Technical Support Site: industrial partnership activities Unknown 

TA-67 Pajarito Mesa: former TA-12; dynamic testing area; archeological sites DU 

TA-68 Water Canyon Site: dynamic testing area with study areas DU 

TA-69 Anchor North Site: undeveloped; buffer for the dynamic testing area Unknown 

TA-70 Rio Grande Site: undeveloped; buffer for the high-explosives test area Unknown 

TA-71 Southeast Site: undeveloped; buffer for the high-explosives test area Unknown 

TA-72 East Entry Site: Protective Forces Training Facility Unknown 

TA-73 Los Alamos Airport: on-site disposal area; incinerator 1950s All 

TA-74 Otowi Tract: water wells, archeological sites, endangered breeding area None 

Miscellaneous Locations of Activities that Involved Los Alamos Personnel

Pacific Nuclear tests: Marshall Islands (1945-51) All 

AK Nuclear tests: Amchitka (Long Shot, Milrow, Cannikin) 1965,1969,1971 All 

NV Nevada Test Site: nuclear tests, Rover nuclear rocket engine program 

Nuclear tests, non-NTS: Fallon (Shoal); Tonopah (Faultless) 1968 

All 

CO Nuclear tests: Grand Valley (Rulison) 1970; Rifle (Rio Blanco) 1973 All esp. 3H; 85Kr 

NM Nuclear tests: White Sands (Trinity) 1945; 

Carlsbad (Gnome) 1961; Farmington (Gasbuggy) 1967 

All esp. 131I; 133I; 135I; 137Cs; 140Ba/140La 

MS Nuclear tests: Hattiesburg (Salmon and Sterling) Unknown 

a Key for table entries:

All = 239Pu; 240Pu; 238Pu; 241Am; 235U; DU; 3

H; 210Po; 227Ac; 226Ra; 

DU = depleted uranium- 238U; 

MAP = mixed activation products (e.g., 41Ar; 7

Be; 11C; 13N; 15O); 

MFP = mixed fission products; 

NU = natural uranium; 

VFP = volatile fission products. 

Element names without number (e.g., plutonium, uranium) indicate isotope not specified. 

a.k.a. = also known as. 

SNM = Special Nuclear Material. 


2-10 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 2 

This page intentionally left blank
1943 1945 1947 1949 1951 1953 1955 1957 1959 1961 1963 1965 1967 1969 1971 1973 1975 1977 1979 1981 

1943 1945 1947 1949 1951 1953 1955 1957 1959 1961 1963 1965 1967 1969 1971 1973 1975 1977 1979 1981 

Figure 2-6: Timeline of Selected Los Alamos Oper

Anchor Site West casting room operational

D Building opens for use

Main Pu processing performed in D Building (mg quantities at first)

First gram-scale quantities of Pu arrived

2,500 experiments had been completed with 51 g of Pu

Water Boiler operated in LOPO mode at TA-2, Omega Site

S Site operational (high explosives casting and machining, burning g

Radioactive Lanthanum (RaLa) implosion tests in Bayo Canyon

Water Boiler operated in HYPO mode

Radioactive Lanthanum source preparation at TA-10 Bayo Canyon site

Firing Sites A & B operational

Untreated liquid radioactive waste discharged to Acid Canyon

Fire in C Shop at TA-1

First large quantity Pu shipment arrived

Pu for Trinity test purified

L Site operational (explosives testing)

Polonium contaminated liquid wastes to Area U beds

Area T adsorption beds used

Pu for Nagasaki bomb purifiedTrinity Test

Nagasaki bombingPu for second combat weapon purified

Pu for first composite weapon core purified

D Building remained in use for metallurgical R & D, analytical work, etc.

Pu production conducted at DP Site (TA-21)

"General's Tanks" used

R Site becomes main site for HE experiments

Firing Sites C, D, E, F added

Firing Sites G & H added

TA-33 tritium handling facility operational

RaLa Source prep at TA-35, "Ten Site"

TA-45 liquid waste plant operated, released to Acid Canyon

TA-21-35 treatment plant into operation

CMR Building operational at TA-3, includ

Rover program active

LAPRE I operated

Omega West reactor operated

Area G dispo

LAPRE II reactor operated

LANL Rover tests in Nevada

LAMPRE I reactor operated

Water Boiler operated in SUPO mode

PHERMEX 

TA-5

TA-21-257 treatment plant into operation

TA-55 authorized 

D Building in original

Technical Area

An S-Site

high explosives

work room

The Trinity Test
2-12 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 2 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-1

Chapter 3: Information Gathering at Los Alamos 

The goal of the information gathering process at Los Alamos was to identify and retrieve information 

relevant to off-site releases of chemicals or radionuclides, or potential health effects, associated with 

LANL-sponsored activities within the State of New Mexico. Information gathering began with a focus on 

centralized records repositories, then progressed to records held by individual groups or divisions. The 

latter were selected on a prioritized basis, that is, those 

most likely to include information of interest. 

The principal method employed for information gathering at 

Los Alamos was what is known as systematic document 

review (or searching). Systematic searching involves 

identifying the document collections that exist at a site or 

facility, both classified and unclassified, then progressing 

through those collections in an appropriate and orderly 

fashion until all potentially relevant documents have been 

reviewed. All reviews were conducted by analysts qualified 

to recognize information that a competent scientist would 

use to evaluate historical releases and/or the potential for 

off-site health hazards. This approach best supports the “leave no stone unturned” goal that best fosters 

public credibility in public dose reconstruction studies. Systematic document searching can be contrasted 

with “directed” document searching, where researchers have identified needs for specific types of 

information and go directly to the document locations or particular types of documents believed most 

likely to contain it. Systematic searching, directed searching, and combinations of the two approaches 

have been applied in dose reconstruction studies in the U.S. over the past 15 years. 

Some quasi-directed searching activities were conducted at Los Alamos as the information gathering 

process progressed. These consisted of re-visiting records collections that had been searched earlier in the 

project to capitalize on information that had been garnered from the initial searches. These subsequent 

search activities were not entirely directed in nature, as they still maintained characteristics of systematic 

searching. However, they were not entirely systematic either, as they had a narrower focus than the initial 

search activities. Another practice employed by the project team was focused systematic searching, in 

which subsets of records within a given collection were identified based on some defined criteria. These 

subsets were then subjected to systematic search. 

 Fig. 3-1. Two LAHDRA analysts 

 review records at Los Alamos 
3-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

Throughout this section the words “record” or “document” are used to describe a number of different 

types of information. In this context, records or documents are not limited to physical documents, but 

also include materials such as electronic databases of information, microfiche records, microfilm records, 

photographs, video, audio recordings, and engineering drawings. In addition to physical records, other 

sources of information explored by the project team included interviews with past and current LANL staff 

members and tours of LANL facilities. 

How Documents were Categorized, Summarized and Catalogued 

When a document relevant to off-site releases or health effects was identified by a LAHDRA analyst, a 

Document Summary Form (DSF) was completed. The DSF provided a bibliographic summary of the 

document and included information on where it was located so it could be retrieved again in the future if 

needed. Copies were requested of documents that were clearly relevant to the estimation of offsite 

releases or health effects. For other documents, such as those that contained supporting information or 

were otherwise not directly applicable, copies were sometimes, but not always requested. A DSF was 

completed for all relevant documents regardless of whether a copy was requested from LANL. 

Copies of documents requested by the project team, as well as all DSFs completed at Los Alamos, were 

required to go through a review process before they could be released. All DSFs and documents were 

reviewed by LANL to ensure they contained no classified information, personal information that was 

protected under the Privacy Act or information that was proprietary or legally privileged. If a document 

had been deemed Official Use Only (OUO) by its originator, the review process expanded further to 

include an effort to contact the originating author or organization and have the OUO designation 

removed. In all but a few cases this was accomplished and the documents were released to the public. 

One aim of the LAHDRA project was to place all of the material retrieved from Los Alamos in the public 

domain. However, there were a few cases where OUO restrictions could not be removed from documents 

desired by the project team. In these instances the documents were provided to the project team for its 

use, subject to appropriate controls for OUO material. 

After receipt from Los Alamos, each DSF and associated document (if any) was assigned a LAHDRA 

Repository Number, and the information from the DSF was entered into a project information database. 

The database fields reflected those from the DSF. The Repository Number was simply a sequential 

number used for indexing the database entries. Documents were scanned to Portable Document Format 

(PDF) files and indexed using Optical Character Recognition (OCR) software to provide a full-text 

searchable electronic version. The PDF files were linked to each database record so a user could access 

the document associated with an entry. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-3

The project information database, which will be described later, was provided to a limited number of 

public libraries in the northern New Mexico and Albuquerque. It was updated periodically as information 

was added. In addition, copies of documents retrieved from Los Alamos were made available to members 

of the public at the Zimmerman Library at the University of New Mexico in Albuquerque. 

The LAHDRA Document Summary Form 

The DSF was revised several times during the information gathering process. A copy of the latest 

version, Revision 7, is shown in Fig. 3-2. Most of the entries on the DSF are self-explanatory. However, 

two that are of particular interest are described here for completeness. 

Item Number/Other Identifier

This field was added later in the project to be used in conjunction with creation of the Document Request 

Log, which will be described later. A separate log was created for each document collection being 

searched. For each log sheet, entries were given a sequential item number. The item number was entered 

on the corresponding DSF so it and any associated copies could be tracked through the review process. 

The item number allowed copies of documents to be readily associated with the corresponding DSF if the 

two became separated. 

CDC Document Category

Analysts selected one of three categories for a document using the criteria below: 

Category 1. Documents that a competent scientist would use in estimating off-site releases or their 

health effects from operations at LANL or other LANL-sponsored operations within the State of New 

Mexico (such as the Trinity test). Examples of Category 1 documents include effluent monitoring 

data, accident reports with estimates of releases, release point information, or results of environmental 

monitoring performed near locations where people lived or recreated. 

Category 2. Documents that contained supporting or confirming information that could be useful in 

estimation of off-site releases or health effects from operations at LANL or other LANL-sponsored 

operations within the State of New Mexico. Examples of Category 2 documents included historical 

descriptions of site activities, notebooks for relevant operations, or process flow sheets. 

Category 3. Documents that could be used to estimate or confirm off-site releases or health effects 

from nuclear weapons complex sites outside of New Mexico or from operations sponsored by groups 

other than LANL at non-LANL sites within New Mexico (such as Sandia National Laboratory). 
3-4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

Item Number/Other Identifier

PUBLICATION DATE: DATA TIME PERIOD: START END ___________

Estimated?  Estimated?  

DOCUMENT TYPE:  Box  Document  Electronic  File Cabinet  Microform  Notebook  Photo/Dwg.

CDC DOCUMENT CATEGORY: 1 2 3 DOCUMENT REQUESTED?  Complete  Partial  None

ORIGINAL LOCATION OF DOCUMENT:  Litigation Support Database ________________________________

 LANL Records Center __________________________  LANL Archives ______________________________

 LANL Reports Library __________________________  Other ______________________________________

POINTS OF CONTACT FOR DOCUMENT

1. 2.

KEYWORDS:

Atmosphere Biological Chemical Chronic Release

Design Effluent Environmental Episodic Release

Ground Water Operational Radiation Radionuclide

Surface Water Terrestrial Uncertainty Waste Disposal

Other:

DOCUMENT ABSTRACT: Original? 

ANALYST COMMENTS

ANALYST: DATE REVIEWED:

ORGANIZATION(S) TECHNICAL AREA(S)

OFFICE USE ONLY

DOCUMENT TITLE

AUTHOR(S)

DOCUMENT NO. PROJECT

S7 Initials S7 Review Date Page Count Entry Date Initials Rep. No.

 

Fig. 3-2. The LAHDRA Document Summary Form (DSF) 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-5

In contrast, documents about activities by LANL personnel that occurred beyond LANL’s boundaries 

but within New Mexico (such as the Trinity test) would fall under Category 1 or 2. Documents 

concerning operations at foreign nuclear weapon sites or nuclear power plants (foreign or domestic) 

were not Category 3 material since such activities were not within the responsibility of the U.S. 

Department of Energy or its predecessor agencies. In general, copies were not requested for Category 

3 documents, but there were cases where copies of Category 3 material were obtained. 

Table 3-1 provides a summary of how documents were categorized based on the location and sponsorship 

of the activity they described. A document could only be assigned one category number. 

Table 3-1: Assignment of Document Category Based on Activity Sponsor and Location 

Location of Activity Activity's 

Sponsor At LANL Within New Mexico 

but not at LANL 

Weapons Complex Site 

Outside of New Mexico 

LANL Category 1 or 2 Category 1 or 2 Category 3 

Others Category 1 or 2 Category 3 Category 3 

The Document Request Log 

Toward the later stages of the project, the information gathering process was augmented to include the 

use of a log sheet called the document request log. Its purpose was to record information about each DSF 

and any associated document copies generated or requested by the project team. Individual log sheets 

were used for each specific LANL records facility or collection where review activities were performed. 

The document request log provided a formal record of material requested by the project team. It was used 

to track items (DSFs and documents) from the time they were requested until they were received. The 

request log became necessary because of significant delays that would sometimes occur between request 

and receipt. In some cases material would get lost in the review process, so the request log provided a 

means for identifying and retrieving missing material. 

A separate request log was created for each document collection or facility being searched. Each entry on 

a given log was assigned a unique item number. Item numbers were used as a reference when tracking 

the progress of material through the review process and for associating documents with DSFs in cases 

where they were not reviewed together. The fields on the log sheets varied somewhat depending on the 

records facility where they were used, but they all included fields for the document title, page count, 

location, accession numbers or other identifiers, and so forth. A request log entry was made for each DSF 
3-6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

regardless of whether the underlying document was copied so there was a complete record of everything 

the project team identified as relevant within a given document collection. The request log also included 

fields for use by the classification reviewers to indicate they had reviewed each document, and whether it 

had been declassified, redacted, etc. 

The Project Information Database 

As they were received from LANL, the bibliographic information from each DSF was entered into a 

Microsoft® Access database created for that purpose. The basic structure of the database was defined by 

the CDC at the outset of the project. As each DSF was entered into the database it was assigned a unique 

Repository Number. A Repository Number was simply a sequential number used for reference and 

indexing. Following data entry, the DSFs and associated documents were filed by Repository Number. 

As the size of the document collection grew and scanning technology matured, a decision was made to 

scan all of the documents received from LANL to PDF files. OCR software was used to create a full-text 

searchable image, within the constraints of the image quality of the original. The OCR process is not 

100% reliable given the poor quality of some of the documents. 

Fig. 3-3 depicts the progression of a document from a handwritten DSF through entry of the DSF 

information into the information database and the creation of a searchable PDF image file. 

The project database, including the searchable image files, was made available to the public at three 

regional libraries within New Mexico: the Zimmerman Library at the University of New Mexico in 

Albuquerque, the Mesa Public Library in Los Alamos, and the Northern New Mexico Community 

College library in Española. Users may search the bibliographic information from the DSFs and perform 

full-text searches of the document images. As mentioned above, the OCR process can miss words or text 

in poor quality originals, so it is recommended that users utilize both full-text searches and searches of the 

DSF information (i.e., fielded or filtered searches) to find information of interest. 

In addition to the Access-based database, the project team developed a Web-based application that is a 

versatile searching tool for the database and scanned documents. The application, called DocSleuth, is 

hosted by ChemRisk and is available over the Internet to project team members and other selected 

individuals. DocSleuth employs sophisticated indexing technology to a flat-fielded version of the project 

database. The database was re-indexed periodically as information was added. DocSleuth allows global 

or fielded searches, or combinations of these, and provides a comprehensive tool for garnering 

information from the large collection of material retrieved from Los Alamos. An image of the DocSleuth 

search screen in presented in Fig. 3-4.
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-7

 Fig. 3-3. Original DSF, DSF printed from DocSleuth, Original Document PDF 
3-8 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

Fig. 3-4. The Search Screen of the LAHDRA DocSleuth Database 

A full-text search of OCR-processed documents is performed for terms entered in this rectangular field. 

Documents are “filtered” to those whose bibliographic data (from DSFs) contain terms entered in these oval fields. More fields can be seen by scrolling to the right. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-9

Public Reading Room for Documents Obtained by the Project Team 

The LAHDRA document repository contains 

paper copies of documents obtained from LANL 

by the project team. As of this writing, the 

repository contains an estimated 264,000 pages 

of documents, filed under 8,370 Repository 

Numbers. A duplicate set of the documents is 

available at the Zimmerman Library at the 

University of New Mexico in Albuquerque 

(Fig. 3-5). This location was selected as the 

official Public Reading Room for the LAHDRA 

project. 

The Zimmerman Library is located on the 

University of New Mexico’s main campus. The library’s Government Information Department is a 

regional depository for government documents. Documents can be requested at the information desk, and 

photocopies can be made at a nominal cost using copiers located in the immediate area. 

Restrictions on the Project Team’s Access to Certain Categories of Information 

Accessing and reviewing documents at Los Alamos National Laboratory has been more difficult than in 

any similar project conducted at the other DOE sites that have been subjects of dose reconstruction 

investigations. The LAHDRA project was impacted by several events at LANL, unrelated to LAHDRA 

activities, that resulted in stand downs of Laboratory operations and the subsequent implementation of 

increasingly restrictive security measures. Initially, these developments severely impeded the team’s 

Directions to the Public Reading Room at the University of New Mexico: 

Head east from the Central Avenue exit from I-25. Continuing east on Central Avenue, pass through 

the signal at University Avenue. UNM will be on the left. The third light after University Avenue will 

be Stanford Drive. Take a left on Stanford Drive to enter the UNM campus. Take another left at the 

"T." On the right will be Visitor Parking. After parking, head north and slightly west across campus. 

Zimmerman Library is just northwest of the Student Union Building. The Government Information 

Department is located in the basement of the library. 

Contact: Dan Barkley, phone: (505) 277-7180; barkley@unm.edu

Fig. 3-5. Dan Barkley of UNM discusses project 

records at Zimmerman Library in Albuquerque with 

CDC project staff 
3-10 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

ability to complete its review, but over time solutions were put in place that allowed the team to complete 

its work in concert with increased information security measures. 

When the project began, project team members that held the requisite levels of security clearance were 

not restricted in their access to classified information in support of systematic search activities. However, 

a few years into the project, following some highly-publicized information security issues at LANL and a 

stand down of its operations, the Laboratory enacted new security practices that encumbered the project 

team’s access to classified documents. These new security practices included denying the project team 

access to specific types of information (discussed below) and requiring analysts to have permission from 

document owners before being allowed to review classified information. The latter constraint was a 

particular problem, especially in the classified reports collection, where many reports were issued by 

organizations other than LANL, many of which no longer existed. In an effort to accommodate this 

requirement, LANL requested that project team members review reports by their title alone. However, 

this was problematic because in many cases document titles are not a reliable means of identifying 

relevant content. Then, at one stage, the Lab determined it was not authorized to grant the project team 

“need to know” for documents issued by organizations other than LANL. This was a reversal from how 

LANL staff had been operating up until that time. Additional impediments were stricter limits on the 

number of project team members that could work in a given location at one time, and the requirement that 

documents be pre-screened for “deniable category information” before team members could review them. 

This presented two constraints. First, the requirement for pre-screening meant the project team could 

only work as fast the contractor LANL hired to do the screening. Second, the presence of the screeners 

counted against the total number of people the project team could have working in a given area. 

In February of 2005; after a number of iterations between DOE, LANL, CDC, and the project team; a 

number of the security restrictions that had been preventing the project team from conducting systematic 

review activities were relaxed. This left the excluded categories of information and the associated 

requirement for pre-screening in place as the mechanism for addressing concerns over “need to know” 

issues that had been raised during internal and external reviews of LANL’s security practices. 

Table 3-2 below summarizes the categories of information to which project team members were denied 

access. These restrictions meant classified information to be reviewed by the project team first had to be 

reviewed by an authorized individual to ensure that no deniable information was present. If deniable 

information was present, a general description of the contents was provided, to the extent practical, to 

allow the project team to make a judgment as to whether the material potentially contained relevant 

information. In general this proved to be a workable, though time-consuming, solution. In the event the 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-11

project team felt denied documents could contain relevant information, a process was available where an 

appropriately-cleared CDC employee could review the material. The reason for the distinction between 

CDC employees and its contractor (the project team) was unclear, since all of the pre-screening of 

classified material was performed by subcontractors hired by LANL. 

Table 3-2. Categories of Information Withheld from the LAHDRA Team by LANL

Summary of Information Gathering Activities for Specific Document Collections 

Document review activities began with an emphasis on the large, centralized records repositories at 

LANL. It then progressed to include records held within specific divisions or groups. Systematic 

searching was the predominant method used for all information gathering activities at LANL. For the 

larger, centralized repositories, systematic search activities generally occurred over multiple stages. After 

an initial systematic review, follow-up review activities were performed as needed to evaluate 

information accessioned since the initial review was completed. 

Nuclear Weapons Design Information– documents relating to nuclear weapon design, such as 

weapon component blue prints, drawings, or other schematic or graphical design information. 

Sigma 14 Information– concerns the vulnerability of nuclear weapons to deliberate, unauthorized 

nuclear detonation. 

Sigma 15 Information– concerns the design and function of nuclear weapons use control systems, 

features, and their components. This includes use control information for passive and active 

systems. 

Sensitive Compartmented Information (SCI)– includes information that has been determined 

pursuant to Executive Order 12958 or any predecessor order to require protection against 

unauthorized disclosure and that is so designated. Includes conventional weapons, security 

systems, foreign relations, and information regarding intelligence sources and methods. 

Special Access Program (SAP) Information– deals with programs that are judged to require access 

limitation beyond that of the three-tiered classification system (Confidential, Secret, and Top 

Secret). These include programs within the Departments of Energy, Defense, and State. For 

example, the Congressional Emergency Relocation Site located under the Greenbriar Hotel in West 

Virginia, built to house Congress and key staff in the event of a national emergency, was designed, 

constructed, and maintained as a SAP for over 30 years until declassified in 1994. 

Foreign Government Information (FGI)– includes information provided to the U. S. Government 

by a foreign government or governments, an international organization of government, or any 

element thereof, with the expectation that the information, the source of the information, or both, 

are to be held in confidence. 

Unclassified Sensitive Vendor Proprietary Information– includes information that is deemed 

sensitive unclassified and touches on areas such as trade secrets and privileged or confidential 

commercial or financial information. 
3-12 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

Centralized Repositories 

The LANL Records Center

A principal focus of the information gathering task at Los Alamos was the LANL Records Center. 

Initially this facility was housed in Building 1001 in Technical Area 21 (TA-21-1001). Later in the 

project the Records Center was relocated to the National Security Sciences Building (NSSB). The project 

team performed records review activities in both locations. In addition to the Records Center, the LANL 

Archives was also housed in Building TA-21-1001 until the time it too was relocated to the NSSB. The 

Archives collection was stored, maintained, and managed separately from the Records Center’s holdings, 

and review of that facility was conducted separately from that for the Records Center. The systematic 

review of the Archives is discussed later in this chapter. 

The original LANL Records Center was a 15,000 square foot building located at 180 6th Street in Los 

Alamos. The function of the Records Center is to receive and catalog records from the various LANL 

groups and divisions, place and maintain them in retrievable storage, and disposition them in accordance 

with DOE retention and disposition guidelines and other associated requirements (such as the moratorium 

on destruction of records deemed pertinent to epidemiological studies). 

Building TA-21-1001 (the original Records Center) was sub-divided into six “bays” denoted A through F. 

It also included a seventh bay, denoted G-Bay, located in a separate building (TA-21-1002) behind the 

primary facility. The primary facility, Building TA-21-1001, was a designated Vault-Type Room, and 

included classified holdings. The records stored in G-Bay were considered unclassified for access control 

purposes. The Records Center holdings were stored in bays B, C, E, F, and G. Each bay contained a 

number of rows consisting of either tall (10-drawer) filing cabinets or shelving. Shelving and file drawers 

from the original Records Center are shown in Fig. 3-6 through Fig. 3-9. The file drawers were used 

primarily to store paper records. The shelving was used to hold records contained in standard, one cubic 

foot storage boxes. There were also a number of mobile storage units used to house media such as 

microfiche and microfilm. Fig. 3-10 and Fig. 3-11 show storage and review of microfilm records in the 

original Records Center. Each bay typically contained a mix of different types (formats) of records and 

records storage media/containers. For example, the tops of the rows of file cabinets were used to store 

boxes and large-sized media such as drawings and blueprints. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-13

Fig. 3-6. Boxes of documents on shelves in the LANL Records Center in 2005 

 

Fig. 3-7. Document review in the LANL Records Center 
3-14 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

 

Fig. 3-8. File drawers used for document storage in the LANL Records Center in 2005 

Fig. 3-9. Review of notebooks in a Records Center drawer
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-15

Fig. 3-10. One of numerous drawers of microfilm in the LANL Records Center in 2005

Fig. 3-11. Review of microfilm in the LANL Records Center in 2005
3-16 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

9

All material accessioned by the LANL Records Center is assigned a Transfer Record (TR) Number. TR 

Numbers are assigned sequentially and are the principal means of identifying, locating, and tracking 

material in the center. Locations of records in the original Records Center were referenced using a “bayrow-shelf” nomenclature, where “shelf” could have been any number of storage locations, such as a file 

drawer or a specific box in a vertical stack of boxes. Thus, the location “B-1-2” would refer to material 

location in B-Bay, Row 1, Location 2. 

The LANL Records Center had been operating near its storage capacity for some time, and the space 

shortage resulted in records frequently being relocated, reconsolidated, transferred to Federal Records 

Centers, or otherwise dispositioned to free up space to accommodate newly-accessioned material. In 

2005 the Records Center began the process of relocating to the NSSB. Many of the records were 

relocated to the NSSB, and many others were transferred to Federal Records Centers. 

The layout of the Records Center in the NSSB is similar to that in the previous facility, though without 

the individual bays. Otherwise, the storage system is similar, and in fact the file drawer storage units 

were physically moved from the old facility to the new one. 

The systematic search of the Records Center may be described as having occurred in four distinct phases: 

initial search activities (up to the work stoppage in 2003 prompted by security issues at the Lab), an 

interim period, resumption of systematic search activities following the work stoppage, and follow-up 

review activities after the Records Center was relocated to the NSSB. 

Initial Systematic Searches of the Records Center: February 1999 – October 2003– The initial 

systematic search for relevant material in the LANL Records Center began in February of 1999 and 

continued until October of 2003. To facilitate identification of what had and had not been reviewed, 

records were marked with one of two rubber stamps. One stamp was used to identify records that contain 

no information pertinent to off-site releases or health effects (Fig. 3-12): 

CDC/NCEH 

REVIEWED 

(in green ink) 

The other stamp was used to identify boxes or drawers that did contain relevant information, that is at 

least one document deemed to be Category 1, 2, or 3 (Fig. 3-13): 

  CDC/NCEH 

DO NOT DESTROY 

(in red ink) 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-17

Fig. 3-12. A Records Center drawer with a green “CDC Reviewed” stamp affixed

Fig. 3-13. A Records Center box marked with red “Do Not Destroy” stamps 
3-18 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

For records stored in boxes, the outside of the box was stamped. For records stored in drawers, an 

adhesive label was stamped and affixed to the drawer. Originally a log entry was made identifying 

everything that was reviewed. These logs, referred to as “box logs”, included the document category 

assigned to the material (i.e., Category 1, 2, 3, or 4), its TR Number, location, the analyst that performed 

the review, and the review date. This information was recorded for all material, regardless of whether it 

contained relevant information. If material was selected for copying, an additional entry was made in a 

separate log identifying the material by its TR Number and location. The purpose of this “review log” as 

it was known was to provide the classification reviewers a current listing of what they needed to review 

and to aide them in locating it. This “review log” was a predecessor to the formal document request log 

initiated later in the project. Material to be copied was flagged using self-stick notes or equivalent to 

make it easier for the classification reviewers or others to find later. Once material was either confirmed 

to be unclassified or properly redacted, it was copied and forwarded for an additional series of reviews to 

confirm it could be released to the public. This purpose of this subsequent review was to screen for 

information that was protected under the Privacy Act, proprietary, attorney-client privileged, etc. The 

review log served as a tool to both identify material in need of classification review and that which had 

been forwarded for the second part of the review process or still needed to be copied. 

Early in the initial review it became apparent the tools and methods originally specified for tracking 

progress and identifying material that had and had not been reviewed were inappropriate for a facility like 

the Records Center. The large volume of the material coupled with its dynamic nature (i.e., high 

turnover) meant handwritten logs were of little use. Boxes and drawers that had been stamped by the 

project team were often re-used to store material that had not been reviewed. This meant the presence or 

lack of one of the stamps was of limited value. Further, the ever-changing number of storage locations 

and constant in-flux of new material made asserting a completion percentage problematic, and presented a 

task that was open-ended. Thus, a more reliable method was needed to keep track of the systematic 

review of the Records Center. 

An electronic database of the Record Center’s holdings was created to allow tracking of what had and had 

not been reviewed by TR Numbers. The project team adapted the database used by the Records Center 

staff to track its holdings. Tables, fields, and LAHDRA-specific search criteria were added as needed, 

including an electronic version of the box log. The box logs and accession/turnover information provided 

by the Records Center staff provided the two sources of data used to maintain the database. As long as 

the database was kept current in terms of records locations and TR Numbers, any discrepancies between it 

and the handwritten box logs gave an immediate indication of either an error in the log or material that 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-19

had been moved or otherwise dispositioned. This greatly simplified the task of tracking material that had 

and had not been reviewed, even for cases where the same locations required review multiple times 

because of records turnover. 

In conjunction with implementing the database for tracking progress, a cutoff accession date was 

established to define a fixed end point for the initial systematic review of the Records Center. The cutoff 

accession date chosen was December 31, 1999. The last Transfer Record assigned prior to this date was 

TR Number 13779. Thus, material in the Records Center having a TR Number 13779 or less was 

targeted for review under the initial systematic review. Records accessioned after January 1, 2000 were 

addressed in subsequent review activities. The cutoff accession date was only applied to hardcopy 

records. 

The database used to manage and track the initial systematic review of the LANL Records Center was not 

used for microform records (that is, microfilm or microfiche). These materials did not suffer from the 

turnover problems that hindered the review of the hardcopy records, so the review of the microform 

records was managed and tracked in a manner more consistent with what was originally conceived. 

Small red or green adhesive dots were applied to microfilm cassettes in lieu of the rubber stamps to 

indicate material that had been reviewed. For microfiche records, the rubber stamps were applied to 

either the sleeve the media was stored in (for individual microfiche records) or to the storage container 

(such as the front of a drawer) if it was a large volume of records. 

Interim Search and Retrieval Activities: September, 2004 to March, 2005– A work stoppage prompted 

by security issues at LANL halted systematic search activities at Los Alamos in October 2003. A large 

backlog of material selected by the project team for copying and release to the public had accumulated. 

An interim task to get this material copied, reviewed, and released began in September of 2004. 

A listing of outstanding material from the initial systematic review was compiled so it could be located 

and placed into the review process. By the end of March, 2005 all of this material had been located and 

submitted for review. By the middle of May, 2005 all of the outstanding material selected by the project 

team during its initial review activities in the LANL Records Center was in the project’s repository. 

In parallel with the task to close out the backlog material during this interim period, a CDC staff member 

made several trips to the LANL Records Center and the LANL Reports Library to close out some other 

outstanding items from the initial search activities. Specifically, the review of hardcopy (i.e., nonmicroform) records at the Records Center and a subset of classified reports in the Reports Library were 

completed. 
3-20 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

Resumption of Systematic Search Activities: February, 2005– Systematic search activities at the LANL 

Records Center (and for the project as a whole) resumed in February, 2005. Review of hardcopy records 

accessioned through 1999 had been completed, so the focus upon resumption of systematic searching was 

completion of the microform records (i.e., microfilm and microfiche). Time was of the essence given the 

pending relocation of the Records Center to the NSSB. 

When work resumed, there were approximately 4,100 cards of microfiche and 2,700 rolls of microfilm in 

the Records Center remaining to be reviewed. Systematic review of the microfiche was completed by 

mid-March of 2005. Systematic review of the microfilm (and thus the LANL Records Center itself for 

the time being) was completed in early June, 2005. 

The resumption of systematic review activities saw a significant improvement in throughput over that 

experienced previously. This was due to a number of important changes that were made to the document 

review and release process, including analysts being allowed to disposition non-relevant material by title 

alone and copy relevant documentation as it was identified. Being able to copy the material as it was 

identified and attach it to the DSF eliminated problems suffered previously with getting copies of what 

the analysts had selected. Another important, but unfortunately, short-lived change was the near-full-time 

availability of a contractor to perform the requisite classification reviews that was also authorized to 

declassify material when appropriate. These changes led to improved throughput of systematic review 

activities, including short turnaround times between when relevant material was identified and when it 

was received by the project team. Further, the adoption of the document request log during this time 

made it easier to confirm that everything the project team had requested was received and to resolve any 

discrepancies. 

Follow-up Reviews in the NSSB– Review of records accessioned after December 31, 1999 took place 

after the Records Center had completed its relocation to the NSSB. This review was performed by 

reviewing the information on the individual TRs and identifying records of interest. The scope of this 

review was limited to records that were stored at LANL, that is, it did not include records that had been 

transferred to the Federal Records Center. 

The LANL Archives

Initially, the LANL Archives was housed primarily in A-Bay of Building TA-21-1001. Some material 

(motion picture reels, for instance) was housed in B-Bay, and additional material (including some that had 

not yet been formally accessioned) was stored in G-Bay in Building TA-21-1002. These are where the 

Archives records were maintained when the project team completed its initial systematic review (with the 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-21

exception of film (motion picture) and video records) in early May of 2006. Subsequently, the Archives 

were relocated to the new National Security Sciences Building in TA-3. Once it was operating in its new 

location the project team performed follow-up activities there to revisit document collections previously 

reviewed and to review any records accessioned since the systematic review was completed. The second 

look at documents previously reviewed was prompted by insights gained from the study of the 

information from the initial review. 

In general, the Archives records were organized into individual folders, which were stored in boxes (see 

Fig. 3-14 through Fig. 3-17). The boxes and folders were constructed of acid-free paper, making them 

suitable for archival storage. Most of the boxes were of a clamshell design which allowed easy access to 

the folders inside. Other types and sizes of boxes were used for some large or odd-sized media, 

microform records, etc. Some non-paper records were stored in cases or cans on Archives shelves (see 

Fig. 3-18 and Fig. 3-19). 

Archives records were organized into collections, with a collection consisting of records covering a 

common subject area (e.g., an individual’s memoirs, the records of a particular facility or group, etc.). A 

collection could be one box or span hundreds of boxes. Each collection was assigned a unique collection 

number, consisting of the year the material was accessioned and a sequential number starting with 001 for 

each year. Boxes were numbered sequentially within each collection, and folders were numbered 

sequentially within each box. Each collection had an inventory listing that gave a brief description of the 

contents of each folder. 

The LANL Archives was a largely static, well-organized collection of records. That plus the availability 

of the inventory listings provided a framework for systematic document searching that did not exist at 

other centralized repositories. The project team began systematic review of records in the LANL 

Archives in June of 2005. The first step in the review process was to obtain the inventory listings for 

each collection. The Archives staff provided these listings to the LANL LAHDRA project office, which 

broke them up into “Pages.” The complete listings were broken up into 52 Pages, with a given Page 

consisting, generally, of hundreds of pages of inventory. (LANL’s choice of “Page” as its nomenclature 

for the inventory listings tended to be a source of confusion until one became familiar with it. A “Page” 

of inventory listings covered many different collections and was by no means a single page of 

information.) 
3-22 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

Fig. 3-14. Moveable shelving units in the LANL Archives in 2005 

Fig. 3-15. Boxes used to store LANL Archives materials
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-23

Fig. 3-16. Boxes used for storage of archived material

Fig. 3-17. A classification officer preparing to review documents selected by LAHDRA analysts
3-24 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

Fig. 3-18. The LANL Archives contain paper documents, audio tapes, video tapes, and microfilm 

 

Fig. 3-19. The LANL Archives includes classified and unclassified motion picture films and videos 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-25

The inventory listings were placed in three ring binders and provided to the project team. Project analysts 

then went through the listings and selected material for review based on the descriptions given. The detail 

in the inventory listings allowed this selection process to be performed at the folder level rather than the 

box level. The selection process was rather broad, as often it was not apparent from the description what 

the material actually was. In such cases the material was always selected for review. Once this selection 

process was completed, approximately 28,235 folders had been selected for review. This equated to 

approximately 25% of the total folders in the Archives at that time. 

In addition to the records selected by the project team for review, a random sampling of 1% of the folders 

in the Archives was also performed. The purpose of this sampling was to select material to be reviewed 

by the analysts to act as a check on both the project team’s document selection process and on the 

accuracy of the Archives inventory listings. The 1% sampling process did not indicate any problems with 

the material selection process or the Archives’ inventories. 

The review of the material selected by the project team, in general, proceeded one page at a time. A set of 

boxes from a given collection was pulled and each folder selected from within those boxes (either by the 

analysts or via the random selection process) was reviewed. Once the review was completed, the 

appropriate stamp (red or green) was applied to the box and the analyst indicated the material had been 

reviewed by initialing and dating the inventory listing for that folder. This process was continued until 

the Page was completed. Deviations from this process were made as needed, such as the advance review 

of excluded material (discussed below) or completing the review for all material in G-Bay (regardless of 

what Page it was under). In the latter case, a priority was made to complete the review of material stored 

in G-Bay under favorable weather conditions. G-Bay was a seldom-used facility with limited climate 

control, so both LANL and the project team wanted these reviews completed after the summer and before 

the winter. Review of Archives material in G-Bay (including that not yet accessioned) was completed 

around the middle of October, 2005. 

Prior to review by the project team, all of the material selected (either directly or through random 

sampling) had to be pre-screened for excluded categories of information by authorized individuals. For 

the Archives, information determined to be excluded by LANL’s reviewers was dispositioned by an 

interactive discussion between the reviewer and a project analyst. (Information was excluded at the folder 

level.) The reviewer gave the analyst a basic description of the contents of the folder and the reason he 

felt some of the material should be withheld from detailed review. This process gave the analysts enough 

information to make an informed decision on the relevance of the material for the LAHDRA project. 

Little of the material selected for review in the Archives was excluded and none of this material was 
3-26 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

thought to contain relevant information. Much of the excluded material came out of the random selection 

process and was not material selected by the project team. The project team went through and addressed 

most of the excluded material in advance so it did not impede the progress of the systematic review. 

As previously discussed, follow-up review activities were completed for hardcopy Archives records 

following its relocation to the NSSB. In 2007 the project team was provided a listing, several hundreds of 

pages in length, of films and video tapes held in the Archives collection. This listing was reviewed 

during 2007 and 2008 and potentially relevant titles were selected for review. In early 2009, a list of 84 

titles was submitted to LANL with a request that they be made available for review. It was determined 

that there was significant duplication within the list, some of the films were old and brittle, and viewing 

would be problematic for some of the requested titles, A plan was put in place to review as many as 

possible during remaining visits to LANL within 2009 as budget permits. 

The LANL Reports Collection and Research Library

Initially, the LANL Reports Collection was housed in a vault facility located beneath the LANL Research 

Library. Along with the Records Center, Archives, and other collections, it too was eventually relocated 

to the NSSB. However, since this move took place after the project team had completed its systematic 

review, this section describes the center as it existed prior to being relocated. 

The Reports Collection contained both classified and unclassified reports published by LANL and 

numerous other entities, in paper copy and on microfiche. The Reports Collection maintained its holdings 

in three principal collections: classified reports, unclassified reports, and unclassified microfiche. The 

project team’s systematic review of the Reports Collection approached each of these three collections 

individually. Fig. 3-20 through Fig. 3-23 show some of the stationary shelving, movable shelving units, 

and Lektriever units that were used in the Reports Collection. 

As with the other systematic document search activities that began early in the project, initially logs were 

kept of everything that was reviewed in the Reports Collection regardless of whether it contained relevant 

information. This practice of formally documenting everything that was reviewed was found to be 

unnecessary and thus was discontinued when document search activities resumed in February of 2005 

following the security stand down. This change, plus that of dispositioning material by title, greatly 

improved the efficiency of the systematic review of the Reports Collection without compromising its 

effectiveness. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-27

Fig. 3-20. Reports on stationary shelving in the LANL Reports Collection vault 

Fig. 3-21. Reports on moveable shelving in the LANL Reports Collection vault
3-28 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

Fig. 3-22. Review of technical reports in the LANL Reports Collection

 

Fig. 3-23. Microfiche copies of reports are stored in “Lektriever” units such as this in the LANL 

Report Collection vault 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-29

Since there were no complete or reliable finding aides for its holdings, the systematic review of the 

Reports Collection was performed by reviewing documents shelf by shelf. The largely static nature of the 

Reports Collection holdings made this an effective procedure. 

Review of the Classified Reports Collection– The classified reports collection consisted of reports that 

were classified at the time of publication. The reports were published by LANL and numerous other 

entities, including other weapons complex sites, military organizations, and contractors. The majority of 

the reports pertained to weapons program activities (testing in particular) and other large defense 

programs, such as Rover. The reports published by LANL included those in the LA-series and reports 

generated by various groups such as SS (material accountability), W-division, X-division, etc. The 

reports were stored on collapsible shelving in alphabetical order. 

The classified reports collection included approximately 3,000 classified report titles issued by LANL as 

LA- or LAMS- reports. Quantities are reported as titles rather than as individual documents since there 

can be multiple copies of a given report in the collection. In addition, the classified reports collection 

contained approximately 32,000 titles from organizations such as other weapons complex sites, other 

defense-related agencies, academic institutions, and private corporations that conducted research on 

behalf of DOE or its predecessor agencies. 

To address the issue of excluded material, ultimately classified reports were reviewed by a LAHDRA 

analyst working in tandem with a reviewer authorized by LANL to pre-screen material for excluded 

information. This arrangement worked well, and the systematic review of the classified reports collection 

was completed in June of 2005. Additional ad hoc reviews of some of the holdings in the classified 

reports collection were subsequently performed to follow-up on information learned from the earlier 

reviews. 

Review of the Unclassified Reports Collection– The unclassified reports collection was similar to the 

classified collection, but contained only unclassified documents. As such, the subject areas covered were 

more broad than those in the classified reports and tended to yield more material of interest to the 

LAHDRA project. 

The Reports Collection contained approximately 10,000 unclassified report titles issued by LANL as LAor LAMS- reports. In addition, images of approximately 25,000 unclassified LA-, LA-MS-, LA-UR, and 

LA-PR reports were available as PDF files in the LANL electronic library catalog. Unclassified reports 

with limited distribution categories, such as OUO (Official Use Only), were not available electronically 

and had to be reviewed in the vault. 
3-30 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

Prior to the heightening of security measures that followed the terrorist attacks of September 11, 2001, the 

unclassified “LA” reports were available to the public on LANL’s web site. Subsequently, those files 

could only be accessed from a computer with a LANL IP address or by certain other government 

computer users. The project team reviewed 100% of the unclassified “LA” reports that were formerly 

available without restriction on the Internet. Most of these reports were reviewed using LANL computers 

at an office made available to the project team at TA-35. 

In addition to those issued by LANL, there were approximately 90,000 unclassified reports in the Report 

Library vault issued by non-LANL entities, including: 

• DOE sites other than LANL, 

• academic institutions, 

• private corporations that conducted research on behalf of DOE, and 

• other defense-related agencies. 

Systematic review of the hard copy holdings of the unclassified reports collection was completed in 

November of 2006. 

Review of the Unclassified Microfiche Collection– Historically, LANL subscribed to multiple UC 

(University of California) distribution codes for DOE-related reports. When the Office of Scientific and 

Technical Information (OSTI) took over the distribution of DOE-related reports, they began distributing 

the reports on microfiche instead of paper. As a result, the LANL Reports Collection contained 

approximately 1.5 million documents on microfiche. In 1999 the LANL Research Library converted to 

an electronic subscription service, so documents were no longer added to the microfiche collection. 

Instead, library staff accessed reports via online databases (not hosted by LANL) upon request. 

All of the microfiche reports were unclassified, but some were marked for limited distribution. Journals 

were not included in the microfiche collection due to copyright laws. Many of the reports in the 

microfiche collection were conference proceedings. The fiche cards were stored in LektrieverTM power 

filing units in alphabetical order (by document number). The documents in this collection included 

approximately 22,225 LA reports, according to the Library Catalog. Duplicates of these reports existed 

between the paper and microfiche collections, so the reports on microfiche did not need to be reviewed 

again if a paper copy of the same report had already been reviewed. Of the non-LANL agencies 

represented in the microfiche collection, the three largest (in terms of number of reports) were DOE 

Energy (~500,000 reports from 1969 to the present), Nuclear Science Abstracts (NSA; ~100,000 reports 

from 1949 through 1976) and NASA (~20,000 reports). 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-31

The Research Library subscribed to two electronic databases, DOE Energy and NSA, and had until 

recently also subscribed to the NASA electronic database. A search of the DOE Energy and NSA 

databases showed that Los Alamos was the authoring institution for approximately 11,000 NSA reports 

and 53,000 DOE Energy reports, or about 10% of the titles in each database. 

Like the other collections in the LANL Reports Library, there was no complete finding aide available to 

allow searching the microfiche collection. The project team and LANL staff members therefore 

performed a cataloging (mapping) of the numerous entities represented in the millions of pages of reports 

contained in the microfiche collection. This produced an estimate of approximately 600,000 cards of 

microfiche in the six Lektrievers. The submitting organizations represented in these cards were 

differentiated into three broad categories to facilitate developing a search plan for this material. For each 

category of material, a fraction was reviewed for information relevant to the LAHDRA project. The 

categories of information and their associated review fractions are given in Table 3-3 below. 

Table 3-3. Review fractions for categories of unclassified microfiche in the LANL Report Collection 

Category Description Review Fraction 

A Reports from DOE or DOE sites, LANL-originated 

reports, and New Mexico-related documents. 100% 

B Reports from DOD, NASA, other U.S. Govt. 

organizations, U.S. businesses, or U.S. universities. 1% 

C Reports from foreign (non-U.S.) organizations. None beyond that performed 

in the mapping process 

The decision not to review the material from non-U.S. entities any further was based on the sampling of 

the documents in the microfiche collection intrinsic to the mapping process. Formal review of the 

microfiche collection was completed in March of 2006. All relevant material identified from the 

Lektriever collection was received from LANL and entered into the LAHDRA database. The majority of 

this material was Category 3 information, i.e., that pertinent to sites other than LANL. 

Review of the LANL Research Library– LANL’s central research library, in general, did not serve as a 

central repository for records. However, it did contain some public domain records such as those 

associated with the “human radiation experiments” initiative and LANL’s annual environmental summary 

reports. The project team searched these collections and retrieved a number of records from them. In 

particular, a number of Health Division records were obtained from the Research Library, as they were 

included among documents associated with DOE’s human radiation experiments project. 
3-32 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

The ES&H Records Center and Other ES&H Records

The initial systematic reviews of the holdings in the Environment, Safety, and Health (ES&H) Records 

Center were completed earlier in the LAHDRA project. More recently the holdings of the ES&H 

Records Center were relocated to the NSSB and housed in the same area as the primary Records Center. 

After the documents were relocated the project team completed follow-up review activities of those 

accessioned since the prior review activities were completed. In all, there were three systematic reviews 

of the holdings of the ES&H Records Center to ensure that material accessioned since the prior review 

was evaluated. 

This summary of document review activities for the ES&H Records Center reflects group and 

organization names that were in use at the time review activities began. Since that time LANL went 

through numerous organizational changes, making the group and organization designations below largely 

obsolete. However, the previous organizational designations have been retained to preserve the summary 

of the review activities in sufficient detail. 

Description of the ES&H Records Center– Prior to its relocation to the NSSB, the ES&H Records Center 

was located in Building 46 at TA-35. The center began operating in 1998. Its purpose was to receive 

records from the various ES&H Groups, catalogue and consolidate them, and eventually forward them to 

the LANL Records Center. Many of the records stored at the ES&H Records Center were recent, i.e., 

from the 1990s forward, but older records were found was well. 

In Building TA-35-46, the records were stored in a combination of 25 rows of shelving and 9 file 

cabinets. The shelving units were used to store standard one cubic foot boxes. The file cabinets were 

used to store a combination of boxes and other items or containers. Often there would also be numerous 

boxes staged in various areas of the center that had not yet been accessioned. Some of these unaccessioned records would also be placed in the shelving units. 

At the time, contents of records stored at the ES&H Records Center were described on CIC Form 170, the 

Records Transfer Request Form. This form defined a unique transfer record (TR) number for each set of 

records submitted to the center. The format of the TR numbers used for materials accessioned by the 

ES&H Records Center differed from those used by the primary Records Center. The ES&H format was 

TR-120-xxxx, where “xxxx” was a sequential number. The TR numbers were used to track records in a 

database maintained for that purpose. Hardcopies of the TR forms were kept in binders, with a different 

binder used for each group. Following its relocation to the NSSB, the holdings of the ES&H Records 

Center were stored on collapsible shelving units within the main Records Center. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-33

Other ES&H Records– Some ES&H groups held records that had not yet been sent to the ES&H Records 

Center or the main Records Center. For example, Group ESH-17 (Air Quality) kept records in file 

drawers that were organized by year. They kept records for the three most recent years and sent those for 

prior years to the ES&H Records Center. Group ESH-20 (Ecology) stored their records in files organized 

by topics such as Biology, Contaminate Monitoring, and Cultural Resources. In general, these types of 

record collections were considered to be active records rather than part of a formal collection. Table 3-4 

shows the groups that existed within the ES&H Division when systematic review activities began, and 

whether they held records independent of the ES&H Records Center. 

Table 3-4. Additional Records held within ES&H Groups 

ES&H Group Additional Records? 

ESH-1: Health Physics Operations No 

ESH-2: Occupational Medicine No 

ESH-3: Integrated Risk Analysis, Management and Communication No 

ESH-4: Health Physics Measurements No 

ESH-5: Industrial Hygiene and Safety Yes 

ESH-6: Nuclear Criticality Safety Yes 

ESH-7: Occurrence Investigation Yes 

ESH-10: Hazardous Materials Response No 

ESH-12: Radiation Protection Services Yes 

ESH-13: ES&H Training Yes 

ESH-14: Quality Management No 

ESH-17: Air Quality Yes 

ESH-18: Water Quality and Hydrology Yes 

ESH-19: Hazardous and Solid Waste No 

ESH-20: Ecology Yes 

Since these additional records were considered to be “active”, a detailed review was not performed as part 

of the initial systematic review for the ES&H Records Center. Instead, the project team generated 

descriptions of these additional records to identify those to be reviewed in the future. These reviews were 

performed under the review of records held by the ENV Division, described later in this chapter. These 

reviews took place following a number of reorganizations and consolidations within the Lab, so the 

groups described later in this report do not necessarily reflect those above. 

Review of the ES&H Records Center– The bulk of the systematic review of the ES&H Records Center 

took place between January and October of 2000. Records were reviewed at their storage location. 
3-34 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

Following review, they were marked using one of the two rubber stamps described earlier based on 

whether they contained any Category 1, 2, or 3 documents. A log entry was made identifying the material 

reviewed by its location and its TR number. The log entry included the document category assigned to 

the material, the analyst whom performed the review, and the review date. A DSF was completed for any 

document identified as Category 1, 2, or 3. 

On several occasions, records that had been reviewed were subsequently replaced with newly accessioned 

records. In general, these new records were also reviewed, meaning that several locations were reviewed 

two and even three times as new material displaced older material in the center. Since the ES&H Records 

Center was an active staging area for records, a cutoff accession date of October 31, 2000 was established 

as a stopping point for the initial review. The rationale for this date was the fact that all of the 

accessioned material in the Center had been reviewed by then and the rate at which new material was 

being accessioned was too slow to justify a continuing effort. Instead, material accessioned after October 

of 2000 would be reviewed at some point in the future. 

A total of 1,187 boxes were reviewed during the initial systematic review of the ES&H Records Center. 

Of these, 227 (19%) were found to contain relevant material. The majority of the relevant material was 

designated as Category 2, as it was primarily records from the 1990s that were already readily available in 

published reports. Examples include AIRNET (NESHAPS) data used in periodic reports required to 

document exposures to the public from LANL operations, and airborne effluent data reported in the 

annual environmental surveillance reports. 

One of the most useful finds from the initial systematic review of the ES&H Records Center were two 

notebooks of working notes and document excerpts that contained data on LANL’s historical, site-wide 

radionuclide releases (Andrews ca. 1973). The first notebook (Volume 1 – Repos. No. 1733) contained 

data from 1948 to 1972. The second (Volume 2 – Repos. No. 1734) contained data from 1972 to 1996. 

These compilations had been assembled by LANL as an element of its response to a request from 

headquarters to assess its historical radionuclide releases. 

In July of 2003 the ES&H Records Center was revisited to review material that had been accessioned 

since the initial systematic review. Copies of all Transfer Requests generated since October of 2000 [TR 

Numbers 120-186 (11/14/00) through 120-358 (6/20/2003) ] were obtained and the records descriptions 

were examined to identify any potentially relevant material. Ten boxes were selected for further review, 

but no additional relevant documents were identified. In early 2009, another follow-up review was 

performed for material accessioned by the ES&H Records Center since the previous review. This review 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-35

was carried out in the same manner as that in July of 2003 and generated the same result: no additional 

relevant material was identified. 

The Engineering Drawings Facility

In February of 2006 the project team began reviewing documents held by the LANL Engineering 

Drawings Facility at TA-63. This facility housed engineering drawings and associated documents 

(memos, letters, specifications, etc.) dating back to the 1940s. The documents, which were all on 

microfilm, included topics such as engineering studies and bases for facility modifications. Modifications 

were often performed to correct issues encountered after a facility began operating, such as ventilation 

problems. The documents in the TA-63 facility therefore included information on such problems and 

their impacts. They also included information such as radionuclide concentrations in soil in the vicinity 

of release points. 

The project team’s review of the TA-63 drawings facility was conducted in a focused, but still systematic, 

fashion. The goal was to obtain material to support the prioritization of radionuclide and chemical 

releases from the early LANL facilities. The initial searching, therefore, was for drawings pertinent to 

Original Technical Area buildings (especially D Building), Omega Site facilities and associated stacks, 

DP Site facilities and ventilation systems, and the Los Alamos town site. 

The TA-63 facility maintained a database of their drawings inventory. The database included fields for 

TA Number, keywords, titles, etc. Drawings were searched by reviewing titles to identify those of 

interest. The selected drawings were then physically reviewed, and copies were requested of those 

deemed relevant to the LAHDRA project. The database was also used to search for drawings by TA 

Numbers. This included residential areas, as these were designated as TA-0. Approximately 1,000 

historical drawings were selected as relevant to the LAHDRA project, obtained from LANL, and scanned 

to make them available via DocSleuth. 

The project team also completed systematic review of the TA-63 microfilm records. As for the drawings, 

this review was conducted in a focused, systematic fashion with emphasis on documents related to the 

original Technical Area, Omega Site, DP Site, or the Los Alamos town site. 
3-36 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

The TA-21 Library

The TA-21 library was a collection of material housed in a portable building at DP West. Its purpose was 

to act as a resource for individuals involved in decommissioning activities there. The facility included 

binders of memoranda, remediation investigation reports, and drawings. Much of this material had 

already been collected by the project team from its review activities in the Records Center and elsewhere. 

Nonetheless, a systematic review of this facility was completed and some documents and drawings of 

interest were retrieved. 

The Records Processing Facility

The Records Processing Facility (RPF) managed records of what was formerly the Environmental 

Restoration (ER) group at LANL. Most of the holdings of the LANL Records Processing Facility, 

located at the Pueblo School Complex, had been scanned to PDF files and were available through an 

electronic document management utility. Review of this material is discussed later in this report. In 

addition to these electronic records, the project team also reviewed some hardcopy records that existed at 

the RPF earlier in the project, and records that had recently been acquired and not yet scanned. 

Division or Group Records and Electronic Databases 

As the project team completed its systematic review activities for LANL’s centralized records collections 

it migrated its focus to records held within division or group offices. These were records that for 

whatever reason were maintained by their custodial organizations rather than one of the centralized 

records centers. These records included electronic databases. It was not the goal of the project team to 

review the records held by every LANL division or group. Rather, the project team selected a subset of 

LANL’s numerous divisions that it felt had the greatest potential for providing information of interest. In 

general this selection process focused on divisions responsible for core Laboratory functions, eliminating 

those that served in only administrative capacities. 

The initial focus of the review of division and group records was the Environmental Stewardship (ENV) 

Division. (As before, the discussions in this section reflect the organization of LANL’s divisions and 

groups that existed when records review activities took place. The division or group titles may not reflect 

the current organizational structure due to frequent reorganizations.) The ENV Division consisted of a 

large number of groups, many of which held records of interest to the project team. Review of these 

records was therefore a substantial part of the team’s activities once reviews at the centralized collections 

had largely drawn to an interim close. Review of records within the ENV Division is discussed later in 

this chapter. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-37

Beyond the ENV Division, project team members also met with representatives of a number of other 

LANL divisions and groups to inquire about their activities and any records they held. The groups and 

divisions represented included: 

• Associate Directorate for Security and Safeguards 

• Chemistry 

• Dynamic and Energetic Materials 

• Earth and Environmental Science 

• Environmental Protection 

• Hydrodynamic Experiments 

• Industrial Hygiene and Safety 

• Materials Science and Technology 

• Plutonium Manufacturing and Technology 

• Radiation Protection 

• Weapons Component Manufacturing 

• Weapons Engineering Technology 

Review activities that resulted from these discussions are described in the subsections that follow. 

ENV Division Records

In May of 2006 the project team obtained a summary of records and databases generated by the groups 

and programs within the LANL Environmental Stewardship (ENV) Division. There were approximately 

50 groups and programs listed, along with a number of electronic databases. The function of most of the 

groups and programs was to collect data needed to demonstrate compliance with state and federal 

regulations or that was otherwise required by the Compliance Order on Consent that was in place between 

LANL and the NMED. (At the time the Consent Order was the principal driver of the Laboratory’s 

environmental remediation and surveillance programs.) Numerous databases had been created within 

ENV Division to store and manage the data collected by these groups and programs. 

The project team met with numerous individuals representing various groups and programs within ENV 

Division. Team members spoke with these individuals about the types of information collected and 

maintained by the groups and programs they represented. These discussions were the basis for the team’s 

approach to selecting what the records to review within ENV Division and for prioritizing these reviews. 

The groups and programs represented in these discussions included: 

• Ambient air sampling 

• Cultural Resources 

• Direct Penetrating Radiation network (ambient monitoring) 

• Environmental surveillance 
3-38 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

• Geographic Information Systems 

• Meteorological monitoring and data 

• NEPA, Environmental Assessment, and Environmental Impact Statement records 

• NESHAP compliance (radioactive emissions) 

• Non-radioactive regulated air emissions and air quality permits (Clean Air Act) 

• NPDES, pesticides and sanitary waste 

• RCRA permits and records 

• Records Processing Facility (environmental restoration and related records) 

• Sample Management Office (sampling and analysis files) 

• Soil and biota monitoring program (including DARHT) 

• Storm water data (Clean Water Act) 

• TA-54 performance assessment 

• TSCA, PCBs, solid waste, and underground storage tanks 

The Domino and PRS Databases– Of the document collections and other information sources identified 

within the ENV Division, the largest by far was the Records Processing Facility’s Domino database. The 

Domino database was an electronic storehouse for historical and current RPF records, i.e., environmental 

restoration files. These included environmental project case files, remediation management records, 

regulatory compliance records, and decontamination and decommissioning records. The records were 

stored as PDF files and managed using the IBM Lotus Domino application. Domino is actually a 

business collaboration package rather than a database application, but as applied to management of the 

environmental restoration documents it functioned similar to a database and thus was referred to as such 

in the vernacular. The Domino application was accessed using a web-based front end that included 

provisions for searching. 

Records in the Domino application were indexed using a unique identifier known as an ERID number. 

The system contained approximately 100,000 ERIDs, amounting to approximately 250,000 documents. 

(A record could contain multiple documents.) Systematic review of the Domino records was performed 

by going through them sequentially by ERID number and reviewing those with titles that were either of 

interest or too ambiguous to allow a judgment. Documents deemed relevant to the LAHDRA project 

were printed and a DSF was completed. 

The RPF maintained another database called the Potential Release Sites (PRS) database. The PRS 

database contained documents related to historical activities at so-called “potential release sites”, i.e., 

solid waste management units or other areas of concern. This database contained far fewer records than 

the Domino database. Review was performed in the same manner as for the Domino database. A listing 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-39

of titles was reviewed to select records of interest for examination. Few records were selected, but some 

information of interest was obtained. 

Other ENV Division Records– Below are other records collection identified within ENV Division that 

were reviewed by the project team. 

NEPA Records: Records pertinent to compliance with the National Environmental Policy Act 

(NEPA) and associated environmental impact assessments were stored in boxes and file drawers at 

TA-59. These records included documents associated with LANL’s environmental impact 

statements and environmental assessments for LANL projects. They also included projects that were 

not required to have any NEPA documentation beyond a Department Environmental Checklist 

(DEC), or an Action Declaration Memorandum (ADM) upon which category exclusion declarations 

were based. 

MAQ Records: The LANL Meteorology and Air Quality (MAQ) group maintained air quality and 

related records at its offices in White Rock, NM. pertaining to open burning activities, beryllium 

operations, and other laboratory activities involving hazardous air pollutants. In general these were 

recent records, going back no more than 5 years. Nonetheless a number of relevant documents were 

identified and retrieved. The review of MAQ records also included meeting with LANL staff 

responsible for the RADAIR (radioactive air emissions), STACKS (stack parameters), and RMUS 

(radioactive material usage survey) databases to gain an understanding of the information these 

resources contained. 

Meteorological Data: Project team members met with LANL staff responsible for acquiring and 

managing meteorological data. Data were gathered from meteorological towers at several locations 

across the LANL site and from local weather monitors. Several reports were obtained by the project 

team, on subjects such as atmospheric dispersion modeling for the Los Alamos area, local 

precipitation data, and other local climatologic data. 

Cultural Resources Group Reports: Project team members met with representatives from the LANL 

Cultural Resources group and reviewed a collection of their reports. Copies were subsequently 

requested of a number of these, as they included historical information about operations at LANL 

facilities. 
3-40 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

The Litigation Support Database

In early 2000, the LAHDRA project team became aware of a number of small databases created for the 

Laboratory Counsel’s office. These databases were known collectively as the Legal Counsel Litigation 

Support Database (LCLSD). Creation of the LCLSD began around 1990 with the scanning of numerous 

historical documents to image files. The documents selected were those potentially pertinent to the 

LANL Lab Counsel’s activities. Many of the scanned documents were also subjected to Optical 

Character Recognition (OCR), creating a searchable file of the text. The database contained 

approximately 500,000 pages of documents. 

During the early stages of the LAHDRA project team members made several attempts to gain access to 

the LCLSD. While the database itself was not made available, in 2003 the LAHDRA team received a 

hardcopy listing of the scanned documents available in five of its sub-databases. For each document the 

listing provided a document number, subject (title), author, addressee, copyee, date, status, and page 

count. The five sub-databases and the number of scanned documents available in each was as follows: 

H-Division 1,442 documents 

Human Studies Project Team 4,767 documents 

Central Records Management 11,198 documents 

Others 10,395 documents 

Records Processing Facility 47,922 documents

Total 75,724 documents 

A description of the information contained in each of these five sub-databases is provided in the following 

section. 

Sub-databases within the Litigation Support Database– 

H-Division: The H-Division sub-database of the LCLSD primarily included monthly (1943-1944, 

1947-1964), quarterly (1965-1975, 1978-1990) and annual (1943, 1947, 1949-1953, 1957, 1987-

1990) Health Division progress reports. It also contained progress reports from groups within the 

former Health Division, such as H-1, Radiological Monitoring (formerly H-6 and CMR-12), and H4, Biological and Medical Research. Both of these groups were responsible for monitoring the use 

of radiological and non-radiological hazardous materials at LANL. Although the H-Division subdatabase contained 1,442 documents, this number was a bit inflated given that it typically included 

three versions of each H-Division progress report: a complete report, a version redacted for Privacy 

Act information, and an abstract of the complete report. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-41

Human Studies Project Team: The 4,767 documents listed in the Human Studies Project Team 

(HSPT) sub-database consisted primarily of weekly status reports, fact sheets, press releases, news 

articles, procedures, phone logs, and other administrative documents generated during the HSPT’s 

document review activities at LANL. The majority of these documents were generated between 

1991 and 1995; however, there were also some historical documents from the 1940s, 1950s, and 

1960s. There were also a large number of documents from the 1970s related to the Karen Silkwood 

case and pion radiotherapy studies, and from the 1958 Cecil Kelley fatality. 

Documents in the HSPT sub-database that were of interest to the LAHDRA project were the weekly 

bibliographies of documents released to the public, inventories of documents in LANL records 

collections, reports from the LANL autopsy tissue program, and H-Division monthly progress 

reports. The HSPT sub-database used a classification system for the H-Division reports it contained. 

The classification categories were 001, Bayo Canyon activities; 002, DOD-related activities; 003, 

human tissue studies; 004, non-Bayo Canyon releases; 005, other DOE contractor (human studies); 

006, tracer studies (plutonium, uranium, radioiodine, tritium, radium, other); 007, history/general; 

008, atmospheric testing programs; and 009, pion radiotherapy. 

Central Records Management: The 11,198 documents in the Central Records Management subdatabase covered the years 1943 to 1965. These documents included 

• Monthly hazard and accident reports for month/year (1946-1954) 

• Weekly health test data (1950-1956) 

• Neutron exposure reports (1946-1958) 

• Personnel exposure reports (1957-1958) 

• Monthly and weekly reports (1951-1958) 

• Monitoring results (1945-1957) 

• Minutes from weekly Section Head meetings (1945-1955) 

• Air Counts, pencil and ink originals (1950-1962) 

• Hand, head, shoe and nose counts (1944-1956) 

• Urinalysis/urine counts (1944-1957) 

• Film badge exposures (1957-1958) 

• Protective Equipment- respirators, clothing (1947-1962) 

• Safety meetings (1961-1962) 

• Experimental shots at TA-33 (1948-1955) 

• Tritium exposures at TA-33 

• SL-1 accident 

• DP Site explosion (1-14-1947) 

• Pajarito accident (1-8-1953) 
3-42 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

Others: The 10,395 “Other” documents were primarily administrative records covering the period 

from 1943 to 1989. Examples of these records are: 

• Contracts and contract modifications 

• Reimbursement authorizations 

• Personnel policies regarding overtime, moving expenses, employee benefits 

• Personnel administrative panel meetings 

• Organization charts (1945-1989) 

• Telephone directories (1944-1989) 

• The Atom (1964-1975) 

• Annual reports to Congress of the AEC (1948-1973) 

However, several other types of documents were also included, such as: 

• Annual environmental monitoring reports (1970-1992) 

• H-Division progress reports (1943-1980) 

• RFI work plans for operable units (1989-1990) 

• Glenn Neely Notes 

• Dept. of Labor log and summary of occupational injuries and illnesses (1989-1992) 

• Occurrence reports 

• Newspaper articles 

Records Processing Facility: As previously discussed, RPF documents were records from the 

Environmental Restoration program at LANL. The 47,922 documents in the LCLSD sub-database 

were also part of the Domino database discussed earlier in this chapter. The smaller number of 

documents reflects the fact the LCLSD sub-database only contained a subset of the total number of 

environmental restoration documents. The project team’s review of the RPF sub-database predated 

its review of the Domino collection. 

Review of the Litigation Support Database

Project team analysts reviewed the hardcopy listings of the document titles in each sub-database and 

selected documents for review. Ultimately, only 5% of the documents available in the five sub-databases 

were selected. The remainder were either clearly non-relevant or had already been captured by the 

project team from other collections. A breakdown of the number of documents selected from each subdatabase is shown below. 

H-Division 86 documents 

Human Studies Project Team 155 documents 

Central Records Management 1,706 documents 

Others 764 documents 

Records Processing Facility 1,102 documents

Total 3,813 documents 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-43

Project team analysts reviewed the selected documents electronically using commercial information 

retrieval and viewing software provided by LANL. The software allowed analysts to review the 

documents in a given sub-database one at a time, establish bookmarks where they left off, or jump to 

specific documents. Relevant documents were printed using a dedicated printer and attached to the 

corresponding DSF. Analysts also checked the LAHDRA project database to determine if a selected 

document had already been retrieved. 

Systematic review of the scanned documents in the five LCLSD sub-databases began in May 2005 and 

was completed in September 2005. Approximately 400 documents (10% of the 3,813 selected for 

review) were selected and retrieved. 

Weapons Engineering and Manufacturing and Weapons Physics Records

Systematic records reviews completed by the project team earlier in the project included a review of 

records held by the Weapons Engineering and Manufacturing (WEM) and Weapons Physics (WP) 

divisions. However, the nature of these records in conjunction with the information security restrictions 

imposed on project team analysts at that time meant only a limited review was possible. The reviews 

were conducted in accordance with a Special Security Plan that was issued in June of 2001. 

The reviews focused on the contents of the WEM and WP vault-type room (VTR) located in the 

Administration Building at TA-3. Most of the documents held by these two divisions were classified and 

contained nuclear weapon design and testing information. All of the classified documents reviewed in the 

VTR were published after 1962. Thus, per the Special Security Plan in place at that time, this meant the 

reviews had to be performed on a restricted-access basis. In other words, project team analysts had to 

review the documents by title alone. They were prohibited from reviewing the contents. 

At the time of the review, the WEM and WP division records consisted of approximately 18,876 

classified documents and 1126 classified photographs. There were also classified video media of various 

formats (e.g. VHS). The project team was not allowed to review the videos. Based on their titles, two 

documents were identified by the project team as potentially relevant. An appeal was made to DOE for a 

team member to be able to review the contents of these documents to determine of they were indeed 

relevant, but it was denied. 

Thirty-six classified safes were also reviewed for potentially relevant information. The safes contained 

7,056 classified documents. Review of these documents (by title alone) did not identify any relevant to 

LAHDRA. 
3-44 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

LANSCE Records

Earlier in the project team members performed a systematic review of records held at the Los Alamos 

Neutron Science Center (LANSCE), which is located within TA-53. The reviews focused on files within 

the Main Administration Building (TA-53-1) and the Radiological Air Monitoring Records Archive 

located in Sector R, Building 3, Room 3R-4 (TA-53-3). Approximately 10,000 documents were reviewed 

in the Main Administration Building. Of these, approximately 2,500 were identified as potentially 

relevant and underwent detailed review. Ultimately 36 of these documents were retrieved. They included 

shift supervisor logbooks that contained daily beam current and beam-hour data from as far back as 1971. 

Forty-five boxes of documents (3,375 documents) located at the Radiological Air Monitoring Records 

Archive (Building 3R) were reviewed. Approximately 20% of these were identified as duplicates. The 

documents contained detailed information on radiological monitoring techniques and results from 1971 to 

the present. Most of them pertained to airborne releases from LANSCE. 97 documents were retrieved by 

the project team. 

Beryllium-Related Records

The project team reviewed records held by the Industrial Hygiene and Safety (IH&S) group at TA-59. 

The focus of this review was older records from the former H-5 (industrial hygiene) group. H-5 was 

responsible for monitoring for beryllium and other hazardous materials used in Lab operations. A number 

of relevant documents were identified 

On several occasions project team members met with the LANL beryllium program coordinator to discuss 

beryllium operations, releases, and records. This individual provided the project team with a number of 

useful reports pertaining to beryllium operations and releases at LANL. 

On recommendation from other LANL staff members, the project team reviewed reference material used 

in preparing the environmental impact statement for the DARHT facility. Several documents were 

retrieved, addressing subjects including releases of aerosolized uranium and beryllium from dynamic 

experiments and concentrations of these materials in local soils. 

Hydrodynamic Testing Records

The project team visited a classified vault in TA-22 that contained records from hydrodynamic testing 

activities conducted by several LANL groups and divisions. At the time the vault contained 

approximately 10 rows of collapsible shelving plus a number of flat-file cabinets used to store drawings 

and radiographs. The hardcopy records stored on the collapsible shelves included chronological files 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-45

(sequential memos and reports by date), correspondence files, and shot folders. The shot folders included 

shot summary reports and other detailed information. Sometimes information on materials included in a 

shot were given in detail (e.g., the mass of a specific material), and in other cases only part numbers were 

given (along with their mass). 

It was not the goal of the project team to perform a systematic review of this material. Rather, the intent 

was to conduct a preliminary review of the types of information contained in the shot records and prepare 

a summary for future reference. Nonetheless, one document was selected for retrieval by the project team 

during its visit. It was redacted as required to make it unclassified and released. Several other documents 

that pertained to materials expended in shot activities in the early 1990s were noted. (By this time 

security restrictions had been relaxed such that appropriately cleared project team members were allowed 

to access the records in the TA-22 vault as long as they did not contain any Sigma 14 or Sigma 15 

information.) 

On several occasions project team members met with representatives from the LANL Hydrodynamic 

Experiments (HX) Division to discuss their activities and records. These discussions led to a box of 

documents describing materials expended in shot activities being compiled and sent to the LANL Records 

Center where it was reviewed by the project team. A number of useful documents, akin to some of those 

seen in the TA-22 vault, were identified and requested. These documents were unclassified, though 

several of them had to remain Official Use Only given their content. 

Other Sources of Information 

Project team members searched the photographic records of the Los Alamos Historical Society and 

obtained prints of photographs and maps of interest. More than 50 photographs were obtained, primarily 

aerial views of LANL facilities and surrounding areas from the 1940s and 1950s. The project team also 

obtained a title listing of photographic records held by the LANL Environmental Stewardship Division. 

Prints were obtained of numerous photographs from the early years of LANL operations at TA-1, TA-2, 

and TA-21. Numerous other photographs were also obtained through records review activities at LANL. 

The project team also obtained several videotape records from the Broadcast Media Gallery of the LANL 

Public Affairs Office. 

As the LAHDRA project progressed, CDC also supported and benefited from a series of interviews 

conducted by Peter Malmgren as part of his "Los Alamos Revisited" oral history project. Trained and 

experienced in anthropology and related fields, Mr. Malmgren has been involved in several oral history 

projects in New Mexico over a span of many years. In his "Los Alamos Revisited" project, the 30-year 
3-46 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

Chimayo, NM resident set out to offer a special perspective on the lives and concerns of retired Los 

Alamos workers. During the December 2000 to March 2003 period that CDC supported his project, Mr. 

Malmgren conducted over 100 interviews. Interviews numbered 1 thru 116 (the number 76 was skipped) 

are summarized briefly, with full names not identified, in Repos. No. 4081 of the LAHDRA document 

collection (Malmgren 2003). The interviews cover a very wide spectrum of jobs and life experiences of 

people who worked at Los Alamos and/or lived in the general area. Detailed transcripts were produced by 

Mr. Malmgren, and the interviews were audio taped. 

Interviews with Past and Current LANL Staff or Other Individuals 

Interviews of current and retired LANL workers and other individuals were conducted by the LAHDRA 

team to assist in the identification and description of operations possibly associated with off-site releases, 

identification of relevant collections of records, and development of an understanding of historical 

operations. Workers sometimes help the document analysts assemble the “big picture” with regard to site 

operations. Interviewees can also identify additional interview candidates with knowledge about specific 

subject areas, assist in the interpretation of information from documents or other interviews, and describe 

record-keeping practices of years gone by. 

Interview candidates can be identified from author or distribution lists from key documents, from division 

rosters or progress reports, or from other interviews. While interviews are typically conducted with 

individuals, group interviews allow participants to jog each others memories, yielding more information 

that would otherwise have been provided. All interviews are voluntary, and interviewees have the option 

to remain anonymous. In these cases, names are excluded from our records. In some cases, people who 

have held security clearances in the past can receive special authorization to speak freely during an 

interview, provided it is conducted in an appropriate facility and in accordance with all regulations and 

guidelines concerning handling of potentially sensitive content. 

Summaries of interviews conducted by the project team are included in the project’s information 

database. The database also includes transcripts and summaries of interviews with cognizant LANL staff 

that were performed by LANL. These records were obtained from the project team’s systematic search 

activities, from the Archives in particular. 

Some of the individuals who were interviewed by the LAHDRA team included: 

• Scott Hughes: graduate student doing research on the evolution of the ES&H program at LANL. 

• J. W. Nyhan: LANL staff member re: stack emissions from DP West. 

• Jim McInroy: LANL staff member re: human tissue analysis program. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-47

• John Miglio: LANL analytical chemist. 

• Jim Lawrence: LANL health physicist. 

• Bill Moss: LANL staff member (health physics and industrial hygiene) 

• Jay Wechsler: LANL staff member (radionuclides in soils) 

• Ron Stafford: LANL staff member re: plutonium handling and releases. 

• Scott Miller: LANL staff member (monitoring for airborne releases) 

• Gary Whitney: LANL beryllium program coordinator 

• Tom Newton: LANL chemist (retired, worked in D Building starting in 1949, then moved to 

CMR Building) 

• Helen Cowan: Former chemist at the Manhattan Project’s “Met Lab.” in D Building at Los 

Alamos during World War II, and later in LASL’s CMR Building. 

D Building Roundtable Discussion 

LAHDRA team members worked with LANL personnel to set up a roundtable meeting with current and 

former Los Alamos workers who were reported to have knowledge of operations and activities D 

Building. D Building, part of the original Technical Area, was the Lab’s original plutonium processing 

facility. The meeting was held on July 25, 2006 at LANL to coincide with key project team members 

being in Los Alamos for a public meeting the following day. Attendance was limited to individuals with 

the required level of security clearance so that classified information could be discussed freely. The 

meeting was videotaped, however, and an unclassified version has been made available to the public. 

Meeting attendees included: 

• Charles D. Blackwell, General Monitoring Section, H-1, retired 

• Carl W. Buckland, Leader, General Monitoring Section, H-1, retired 

• W. Clarence Courtwright, explosives safety engineer 1955-1991, retired 

• Raymond Garde, LANL, retired 

• Donald R. Gibbons, LANL, retired 

• Joe Vigil, LANL, retired 

• Jack Buddenbaum, LAHDRA team member 

• Bob Burns, LAHDRA team member 

• Joe Shonka, LAHDRA team member 

• Tom Widner, LAHDRA Project Director 

Plutonium release estimates were not located for D Building so the project team strived to learn as much 

as possible about the processing that was performed there. The goal was to determine methods for 

estimating how much plutonium could have been released. At the roundtable meeting, LAHDRA team 

members described what they had learned about D Building and the activities there. Attendees were 
3-48 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

asked if they could address specific questions that remained, such as details of key steps in early 

plutonium processing, generation of airborne contamination, design of ventilation systems and some 

filters that were added, and indicators of environmental contamination. Unfortunately the participants 

knew very little about D Building, but the project team did learn some useful information about other 

LASL operations. 

Summary Statistics 

Over the course of the LAHDRA project team members reviewed millions of pages of information 

resulting in the retrieval of approximately 264,000 pages of material relevant to the estimation of offsite 

releases of chemical or radionuclides from LANL or associated health effects. This information is 

summarized in the 8,372 records that make up the project’s information database. 

Table 3-5 through Table 3-7 below show the breakdown of documents retrieved by the LAHDRA project 

team by document category, by where the documents were found, and by decade of publication. It should 

be emphasized these statistics reflect the documents identified by the project team as relevant to the goals 

of the LAHDRA project during its review activities. By no means do they reflect the overall distribution 

of documents at LANL, especially where publication dates are concerned. 

Table 3-5. Breakdown of LAHDRA documents by assigned category

Document Category Fraction 

Category 1: information directly applicable to estimation of offsite releases or health 

effects from LANL operations within New Mexico. 44% 

Category 2: supporting or confirming information useful in estimation of offsite 

releases or health effects from LANL operations within New Mexico. 46% 

Category 3: information relevant to estimation of offsite releases or health effects for 

other DOE or predecessor agency sites 10% 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3 3-49

Table 3-6. Breakdown of LAHDRA documents by location of origin

Document Location Fraction 

LANL Records Center 37% 

LANL Reports Collection 19% 

LANL Archives 13% 

Domino Database 10% 

LANL Research Library 5% 

Litigation Support Database 4% 

ES&H Records Center 3% 

Engineering Drawings Facility 2% 

All other locations 6% 

Table 3-7. Breakdown of LAHDRA documents by publication date

Decade of Publication Fraction 

1940s 14% 

1950s 16% 

1960s 17% 

1970s 20% 

1980s 14% 

1990s 16% 

2000s 2% 

Unknown 0.1% 
3-50 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 3

References 

Andrews LL. Los Alamos National Laboratory site releases up to 1972. Los Alamos Scientific 

Laboratory. ca. 1973. Repos. Nos. 1733, 1734. 

Malmgren P. Brief Summaries of 115 Interviews Performed under the "Los Alamos Revisited" Oral 

History Project 2000-2003 2003. Repos. No. 4081. 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4 4-1 

Chapter 4: Plutonium Processing at Los Alamos 

One of the important early roles of the Los Alamos laboratory was the processing of the newly created 

and largely unknown material plutonium (Hammel 1998). The assignments taken on by Project Y 

scientists in the mid-1940s were to: 

• Perform the final purification of the plutonium received at Los Alamos, 

• Reduce the plutonium to its metallic state, 

• Determine the metal’s relevant physical and metallurgical properties, and 

• Develop the necessary weapon component fabrication technologies. 

Los Alamos was the first site in the world to receive quantities of plutonium large enough to manufacture 

weapon components. Initial plutonium processing was performed in the Original Technical Area, which 

was located near Ashley Pond and later became known as Technical Area 1 (TA-1) (see Fig. 4-1). 

 

Key to Selected Buildings: C- Shops U- Chemistry and Physics Labs 

 D- Plutonium Plant V- Shops 

 E- Theoretical Division Offices W- Van de Graaff Machines 

 G- Graphite Fabrication X- Cyclotron 

 J- Research Laboratories Y- Cryogenics Laboratory 

 Q- Medical Offices Z- Cockcroft-Walton Generator 

 R- Laboratories Gamma- Research for M Division 

 S- Stockroom Sigma- Metals, Plastics, Ceramic 

 Med Lab = Medical Laboratory Fabrication 

Fig. 4-1. Map of the Original Technical Area (later called TA-1)
4-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4

Early Plutonium Processing at D-Building 

The initial handling and processing of plutonium that took place at the original technical areas involved 

the following main facilities: 

• D Building- housed plutonium chemistry, metallurgy, and processing 

• D-2 Building- housed contaminated laundry and glassware decontamination 

• D-5 Sigma Vault- storage facility for 239Pu and 235U 

• ML Building- Housed the Medical laboratory, site of human uptake and excretion 

studies by H-4 and H-5 groups and urine assay 

D Building (see Fig. 4-2) in LANL’s Original Technical Area was the first site in the world in which 

plutonium was handled in visible quantities, purified, converted to metal, and used to fabricate atomic 

weapon parts. Because plutonium was a newly discovered element available only in milligram quantities, 

there was a great deal of pressure on scientists to perform the necessary metallurgical experiments as 

quickly as possible once gram-scale quantities of plutonium became available. At the time, impurities 

were of great concern, because α-particles are emitted from plutonium at a rate that is over 1,000 times 

greater than that of uranium. Upon colliding with light-element impurities, these α-particles release 

neutrons, greatly increasing the chance of a premature fission reaction occurring before much of the 

plutonium reaches a super-critical state. A premature ignition, known as a “fizzle”, would greatly 

diminish the explosive power of the weapon. 

Fig. 4-2. D Building in the original Technical Area on December 4, 1946 (looking north). Photo courtesy Los Alamos Historical Society (from LAHM-P1990-40-1-3029).
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4 4-3 

D-Building was constructed as an answer to this impurity problem in December 1943. To mitigate lightelement dust from settling onto experimental surfaces, D-Building was built with a state-of-the-art air 

conditioning and ventilation system that provided laboratory conditions that were as dust-free and clean 

as possible. The building’s air intakes were filtered, but its exhaust vents were not. Starting in late 1943, 

scientists and engineers in D Building used equipment and procedures that are considered extremely 

crude by modern-day standards to process the new and largely unknown element plutonium under 

demanding schedules and extreme wartime pressures. Progress reports indicate that D Building and its 

roof became highly contaminated, and about 85 rooftop vents released contaminated air without 

monitoring and for the most part with no filtration. A former Los Alamos plutonium worker wrote that 

“During the War years, partly because of ignorance and partly because of the stress of wartime 

conditions, operations with plutonium in D Building were conducted with greater laxity than has ever 

been tolerated since” and “D Building was known to be hotter than a firecracker” (Coffinberry 1961). 

There are no records or LANL estimates of airborne plutonium releases from D Building, which ceased 

main plutonium production functions when DP West site became operational in late 1945 but remained 

active until around 1953. 

Flow of Plutonium Operations within D Building 

Operations within D Building can be considered a chemical process with the key objective of converting 

plutonium nitrate into the highly purified metallic hemispheres used in the Trinity and Nagasaki devices. 

While many other supporting projects were conducted within D-Building, including uranium chemistry 

and metallurgy, design of tampers and polonium initiators, as well as the development of various 

refractory materials, this report focuses specifically on the numerous stages of plutonium processing. 

These stages are represented generally by the flow diagram shown in Fig. 4-3, which most accurately 

represents plutonium processing from about December 1944 until D-Building was decommissioned in 

September 1945. These production-scale processes, in operation for only about 9 mo, were refined from 

many months of prior chemical and metallurgical research starting in December 1943 when construction 

of D-Building was completed. It is most likely, however, that the vast majority of plutonium 

contamination was a direct result of these production-scale operations, as the first few milligrams of 

plutonium didn’t arrive on site until January 1944, and gram quantities until March 1944 (Hammel 1998). 

Moreover, by late April 1945, D-Building had produced only about 1 kg of plutonium (see Fig. 4-4), yet 

would receive about 26 kg of additional plutonium from Hanford Site in Washington (Site W) by the end 

of August 1945, as shown in Fig. 4-5 (Site Y 1945). Because of this trend, this report focuses mainly on 

the production-scale processes.
4-4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4

CM-10

Recovery

Pu → PuNO3

CM-11

Metallurgical

experiments

CM-8

Reduction

PuF4 → metallic Pu

CM-5

Fluorination

PuO2 → PuF4

CM-5

Purification

PuNO3 → Pu(III) oxalate

CM-5

Pu(III) oxalate → PuO2

PuNO3 paste 

from W

Pu(III) 

oxalate PuO2 PuF4

Slag, contaminated 

crucibles, etc.

PuNO3

syrup Supernatants containing Pu

“Dry Chemistry”

CM-11

Fabrication:

remelting, casting, cold 

forging, rolling, drilling, 

shearing

Combat hemispheres

Metallic Pu for 

research Used metallic Pu samples

Residues

(small)

Residues

(small)

CM-11

Surface protection, 

coating, electroplating, 

etc.

95-97%

3-5%

2 × 50,000 

gallon 

Waste tanks

at DP site

“Wet Chemistry”

95%

-99%

1-5%

Metallic Pu for 

research

Oxides, scrap metal

Various Pu solutions and suspensions

CM-10

Recovery

Pu → PuNO3

CM-11

Metallurgical

experiments

CM-8

Reduction

PuF4 → metallic Pu

CM-5

Fluorination

PuO2 → PuF4

CM-5

Purification

PuNO3 → Pu(III) oxalate

CM-5

Pu(III) oxalate → PuO2

PuNO3 paste 

from W

Pu(III) 

oxalate PuO2 PuF4

Slag, contaminated 

crucibles, etc.

PuNO3

syrup Supernatants containing Pu

“Dry Chemistry”

CM-11

Fabrication:

remelting, casting, cold 

forging, rolling, drilling, 

shearing

Combat hemispheres

Metallic Pu for 

research Used metallic Pu samples

Residues

(small)

Residues

(small)

CM-11

Surface protection, 

coating, electroplating, 

etc.

95-97%

3-5%

2 × 50,000 

gallon 

Waste tanks

at DP site

“Wet Chemistry”

95%

-99%

1-5%

Metallic Pu for 

research

Oxides, scrap metal

Various Pu solutions and suspensions

Fig. 4-3. Flow chart of plutonium operations in D Building
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4 4-5 

Fig. 4-4. Monthly amounts of plutonium produced from plutonium nitrate in D-Building. This graph is 

not cumulative− by 1 September 1945, purification operations were producing just over 9 kg of purified 

plutonium per month, roughly ten times what the rate had been on 1 April 1945 (Hammel 1998) 

Fig. 4-5. Cumulative amounts of plutonium received from Hanford in 1945 (Site Y 1945) 
4-6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4

The bulk of plutonium arrived at D Building in the form of relatively impure plutonium nitrate 

manufactured at the Hanford Site. Fig. 4-6 shows one of the shipping “bombs” that were used to 

transport the material known as “49” or “product.” A relatively small amount of the nitrate also arrived 

from the Clinton pile at Oak Ride, TN (Site X), though this material was used mainly for research 

purposes. As shown in Fig. 4-3, these nitrates were first converted into plutonium (III) oxalate by wet 

chemical techniques. This oxalate slurry was then sent to the dry chemistry, or dry conversion, processes 

in which the oxalate was first thermally converted into plutonium oxide (PuO2), and then fluorinated 

using a mixture of hydrogen fluoride (HF) and oxygen, forming plutonium tetrafluoride (PuF4). This 

plutonium halide was then reduced in the presence of a more electropositive metal such as calcium, 

resulting in the formation of plutonium metal. The metal was then remelted and fabricated into a variety 

of shapes for metallurgical experiments and coated to protect the surface from oxidation. After each 

metallurgical experiment, the plutonium specimen was returned to the recovery group, converted back to 

plutonium nitrate, and sent to purification, where it was repurified, re-reduced, remelted, recast, and 

refabricated. In this way, a very large amount of data was collected using the relatively small amounts of 

plutonium available at the time. A more detailed description of plutonium processing in D Building that 

was prepared by the LAHDRA team is available elsewhere (Knutsen and Widner 2007). 

By 31 August 1944, J. Robert Oppenheimer stated in a letter that a total of only 51 g of plutonium had 

been received at Site Y. Remarkably, he noted that this material had been used in “approximately 2500 

separate experiments,” and “the overall loss per experiment has been about one per cent” (Hammel 1998). 

An open hood that was used in D Building for production-scale purification is shown in Fig. 4-7. The 

associated apparatus, most of which was made of glass, is depicted in Fig. 4-8 (Wahl 1946). Irradiation 

of glassware caused it to become brittle, and the ether used in the processing was a recognized fire hazard. 

A furnace used for fluorination and oxidation reactions is shown in Fig. 4-9. The manual transfer of dry 

powders from one step to the next in platinum “boats” was problematic and led to some dispersal of 

material in the building. Stationary “bomb” reductions of plutonium tetrafluoride to plutonium metal 

were conducted in induction furnaces like the one shown in Fig. 4-10, and cylinders of plutonium metal 

were pressed into hemispheres using heated presses like the one shown in Fig. 4-11. 

Between each stage in the process, plutonium compounds were stored in vaults and monitored by the 

Quantity Control group to prevent critical masses of plutonium from accumulating. Fig. 4-12 documents 

the processing of plutonium for four weapon cores in D Building during 1945– one for the Trinity test, 

the first combat bomb (used in Nagasaki), a second combat bomb (not needed in Japan), and the first 

“composite” core that used active material in addition to plutonium (Wahl 1947). 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4 4-7 

Fig. 4-6. Plutonium was received from Hanford in 80 g and 160 g batches in "shipping bombs" (right) 

as a slurry of plutonium nitrate. Shipping bombs were transported in protective cases shown on the left. 

(Photo IM-9:1831 courtesy of LANL)

Fig. 4-7. Production-scale purification was conducted in hoods that could be flooded 

with carbon dioxide in the event of an ether fire. (Photo IM-9: 1829 courtesy of LANL)
4-8 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4

Fig. 4-8. Production-scale (160 g) purification apparatus (from Wahl 1946).
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4 4-9 

Fig. 4-10. This induction furnace powered by a 20 kW high frequency converter inside a fume hood 

was used to fire large-scale bomb reductions (from Baker 1946). (Photo IM-9:1824 courtesy of LANL)

Fig. 4-9. A furnace that was used for fluorination and 

oxidation reactions (Photo IM-9: 1832 courtesy of LANL)
4-10 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4

Fig. 4-12. Graph that documents purification of plutonium for four weapon cores in D Building during 

1945 (from Wahl 1947)

Fig. 4-11. Evacuated hot presses like this were used to form 

hemispheres of plutonium (Photo IM-9:5090 courtesy of LANL)
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4 4-11 

Release Estimates for D-Building Plutonium Processing 

Because of the lack of effluent measurements for operations in D Building during World War II, 

plutonium releases were estimated for each plutonium processing step using heuristics and experimental 

results compiled by the US Department of Energy in a document entitled “DOE Handbook – Airborne 

Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities” (USDOE 1994). 

Although the Handbook is primarily intended to characterize accidental airborne radionuclide releases, 

experimental results presented therein lend themselves well to the characterization of releases within D 

Building, as many plutonium processing operations were conducted in an open environment under similar 

conditions. The Handbook is broken into a number of sections characterizing releases of plutonium 

compounds through a number of mechanisms. To estimate plutonium releases from D Building, each 

processing step was divided into a number of conceptual release mechanisms based on process 

descriptions contained in original LASL documents. For each conceptual release mechanism, an 

analogous experiment was identified in the Handbook, which provides estimates of airborne release 

fractions (ARF) and respirable fractions (RF). These estimates were used to calculate the source term, 

which is the mass or activity of a radionuclide released during each conceptual release mechanism. While 

details of this assessment are documented elsewhere (Knutsen 2007), methods and results are summarized 

below. 

Within the release estimation process adopted by USDOE (1994), the source term is a product of a 

number of parameters: 

Source Term = MAR × DR × ARF × RF × LPF 

The material at risk, MAR, is defined as the mass of plutonium present at each conceptual release. For 

example, fluorination operations were carried out at a nominal scale of 160 g, which represents the MAR 

for this operation. The Handbook defines the damage ratio, DR, as the “fraction of the MAR impacted by 

the accident-generated conditions” and notes that a degree of interdependence exists between the DR and 

MAR, as some analysts choose to exclude radionuclides from the MAR that would not be affected by a 

given event. In this analysis, the MAR is defined to include only plutonium available for release in each 

process step, and DR is set to unity in all cases. The airborne release fraction, ARF, is the fraction of 

plutonium aerosolized during each conceptual release mechanism. This parameter is highly dependant on 

the release mechanism, and ranges in this analysis from 1.3×10-7 for air blowing slowly over a solution of 

plutonium nitrate to 2×10-3, representing a bounding estimate for liquid entrainment resulting from 

rapidly boiling solutions of plutonium nitrate. The respirable fraction, RF, represents the fraction of 
4-12 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4

particles in a released aerosol small enough to be inhaled into the human respiratory system. The RF also 

provides a method of estimating the fraction of aerosolized plutonium that could potentially reach the 

rooftop of D Building via its ventilation system. The leak-path factor, LPF, is the fraction of aerosolized 

particles that could be transported through a containment mechanism. 

In this analysis, the LPF is used as a means to estimate plutonium released from apparatuses with 

methods for containment in place. For example, production-scale purification and reduction processes 

were designed to mitigate aerosolized releases, and the LPFs for these processes were set to a small value 

based on professional judgment. The authors recognize that a high degree of uncertainty is associated 

with each of these parameters. Therefore, a Monte Carlo simulation was conducted to assess the 

sensitivity of each parameter to the overall D-Building source term. While the Handbook notes that 

estimated parameter ranges “should not be used as a basis for an ARF statistical distribution” and 

“specifically rejects citation as a defensible basis for such attempts,” a Monte Carlo approach was used in 

this analysis as a means to assess parameter sensitivity and to provide some context to the range and 

uncertainty associated with release estimates. 

Shown in Table 4-1 are source terms estimated for various plutonium processing steps including 

purification, dry chemistry, and reduction, in addition to the recovery of plutonium from residues 

generated by each process. Note that source terms presented in Table 4-1 are calculated from nominal 

values of ARF and RF for conceptual release mechanisms presented in the Handbook. Thus, the total 

estimated source term of roughly 0.3 Ci is a nominal estimate, and a distribution of estimates shown in 

Fig. 4-13 reveals a fairly large uncertainty, with a 95%-ile estimate of over 1 Ci. The details of release 

estimates from one of the main plutonium process, plutonium recovery, are discussed below to illustrate 

the process that was used. 

Releases from Plutonium Recovery 

Recovery operations (Recovery) involved some open-air processing steps, and it was one of the most 

contaminated groups in D Building (Duffy et al. 1945, Hemplemann et al. 1973). Recovery was 

conducted without effective containment mechanisms because of the large variety of plutoniumcontaining residues that Recovery received. This large variety of residues also makes it exceedingly 

difficult in this analysis to characterize releases from all Recovery operations. Instead, releases associated 

with more routine and well-documented recovery processes were focused on. As shown in Table 4-2, the 

bulk of the plutonium-containing residues received for recovery were purification supernatants, 

metallurgical samples (plutonium metal, alloy, skulls, scrap), and materials from reduction/remelting of 

crucibles and slag (Garner et al. 1945). 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4 4-13 

Table 4-1. Summary of conceptual release mechanisms and source terms for several plutonium processes conducted from 1943 through 1945 

Process / Conceptual release mechanism

Number

of runs

Mass of Pu 

entering 

each run (g)

Mass of Pu 

processed 

(kg)

Number of

releases per 

nominal run

Release 

Fraction

Release 

Fraction (ppm 

by mass)

Source term

(mg)

Purification processes (160 g nominal scale)1 207 151 31 6 6.4E-07 0.6 20

Transfer releases 5 6.4E-07 0.6 20Evaporation releases 1 4.2E-09 0.0 0.13

Recovery of process "A" purification supernatants2 130 16 2.1 18 5.6E-05 56.3 116

Transfer releases 12 2.2E-05 22.0 45Steam releases (simmering) 2 2.9E-06 2.9 6Liquid entrainment from sparging 1 2.5E-05 25.2 52Filtration releases 3 6.2E-06 6.2 13

Recovery of process "B" and "C" purification supernatants1,2 77 16 1.2 16 3.0E-05 30.4 37

Transfer releases 12 2.2E-05 21.7 27Steam releases (simmering) 1 2.6E-06 2.6 3Filtration releases 3 6.1E-06 6.1 7

Dry Chemistry and Reduction 29.16 7 2.9E-05 29.0 845

Dry ignition release 1 4.6E-07 0.5 13Transfer of plutonium oxide powder into fluorination reactor 1 2.8E-05 28.0 816Fluorination of plutonium oxide powder 1 3.9E-08 0.0 1Transfer of plutonium fluoride into glove box 1 3.9E-07 0.4 11Transfer of plutonium fluoride within glove box 2 7.8E-08 0.1 2Removal of plutonium button and transfer of MgO liner to Recovery 1 2.0E-08 0.0 1

Recovery of reduction crucibles 0.7 13 3.2E-05 31.6 22

Transfer of pulverized crucibles 1 3.9E-07 0.4 0Transfer of solutions 8 1.9E-05 19.1 13Steam releases (simmering) 2 5.8E-06 5.8 4Filtration releases 2 6.3E-06 6.3 4

Peroxide recovery step 7.6 8 6.1E-04 614.0 4680

Transfer Releases 5 1.3E-05 12.8 97Steam releases (simmering) 0 0.0E+00 0.0 0Steam releases (boiling) 2 6.0E-04 598.0 4559Filtration Releases 1 3.2E-06 3.2 24

Total source term: 5721Total source term (Curies): 0.35

1Processes combined due to similar release mechanisms2Not including peroxide recovery step
4-14 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4

0%

1%

2%

3%

4%

5%

6%

7%

8%

0 0.5 1 1.5

Source Term (Ci)

Fraction of Estimates .

Table 4-2. Types of residues submitted for recovery, April-September 1945 (Garner et al. 1945) 

Type of Residue Pu mass (g) Fraction of Total Pu

Purification supernatants 3297 43%

Reduction liners, slag and remelt crucibles 684 9%

Metal, alloy, skulls, scrap 3334 44%

Pickling and plating residues 130 2%

Analytical and misc. residues 178 2%

Total: 7623 100%

Fig. 4-13. A distribution of release estimates based on a sum of distributions 

associated with individual release mechanisms 

50th

percentile 

95th

percentile 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4 4-15 

As shown in Table 4-1 and depicted graphically in Fig. 4-14, the recovery of plutonium from the “A” 

purification supernatants consisted of 18 conceptual releases. Twelve of these releases consisted of 

“transfer” releases (Abbreviated “T”), which describe releases resulting from the entrainment of solutions 

into air while they are pumped from one process step to the next using a centrifugal pump or a steam jet 

(Duffy et al. 1945). For lack of more representative experimental data, this release was modeled as a 

liquid spill from a height of 1 m. ARF values for this release were based on experimental results (Sutter 

et al. 1981). In these experiments, ARF values from 1×10-6 to 1.6×10-5 were measured. For the purposes 

of this analysis, a log-normal distribution was selected with 1% and 99%-ile values set to represent the 

range of experimental values for ARF. The recommended RF value of 0.8 was chosen to reflect 

experimental results. 

As shown in Fig. 4-14, there were three filtration steps (abbreviated “F”), with release mechanisms 

assumed to be similar to transfer releases. Some of the most hazardous steps in Recovery involved 

adding solid sodium hydroxide to solutions of plutonium salts. Because the dissolution of sodium 

hydroxide is highly exothermic, “considerable steam was released during the neutralization, resulting in a 

contamination hazard” (Duffy et al. 1945) [p. 17]. This release mechanism (labeled “Simmer” on Fig. 4-

14) was modeled using data from experiments (Mishima et al. 1968) in which the fraction of boiling and 

simmering solutions entrained in flowing air was measured. Mishima et al. (1968) measured ARF values 

of 1.3×10-6 to 4.5×10-6. For this analysis, a uniform distribution across this range was chosen. An RF 

value of unity was selected based on experimental results published in 2003 that include measurements of 

size distributions of entrained liquid droplets above boiling solutions and found that over 99% of 

entrained droplets were smaller than 10 μm (Cosandey et al. 2003). 

A fourth release mechanism occurs when plutonium solutions were sparged with sulfur dioxide gas for 

15-20 minutes, labeled “Sparge” on Fig. 4-14. This release mechanism was modeled using experimental 

results published in 1986 that summarize liquid entrainment across a range of superficial gas velocities 

(Borkowski et al. 1986). The bulk of ARF measurements appear to be log-normally distributed and fall 

between 10-5 and 10-4. To capture these results qualitatively, a log-normal distribution with the 1%-ile 

and 99%-ile values of 2×10-6 and 1×10-3, respectively, was selected for this analysis. The conceptual 

release mechanisms for recovery of plutonium from residual supernatants from the “B” and “C” 

purification processes were similar, but contained only one “simmering” release and no releases from 

sparging, as the sulfur dioxide step was not needed for these residues. 
4-16 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4

As shown in Table 4-1 and Fig. 4-15, releases from the recovery of plutonium from reduction slag and 

crucibles are characterized by 13 release points, consisting of eight liquid transfer releases, two releases 

from simmering, two releases from filtration, and one release associated with the transfer of crushed 

crucibles and slag. A final step in all recovery processes, peroxide precipitation was used to separate 

plutonium from a number of rare earth elements. Release mechanisms in this processing step, shown in 

Fig. 4-16, are associated with five liquid transfer operations, one filtration, and two boilings. There were 

two significant release mechanisms that occurred during the peroxide process. The first occurred when a 

30% solution of hydrogen peroxide was added to a solution of plutonium nitrate. Upon addition, the 

hydrogen peroxide would effervesce, an effect that scientists tried to mitigate by cooling the mixture to 

4°C. It was documented in 1945 that “the spray from the ‘peroxiding’ operation as carried out in 

Building D was a major source of contamination” (Duffy et al. 1945)[p. 34]. An additional source of 

contamination presumably occurred in the final Recovery step, which involved boiling solutions of 

plutonium nitrate over a steam bath in 600 mL beakers, concentrating them into a “thick syrup” (Duffy et 

al. 1945)[p. 32]. 

Release Summary 

Heuristics and experimental results compiled by the USDOE that characterize the accidental release of 

plutonium compounds were used to estimate the source term associated with plutonium production 

operations within D Building from 1943-1945. The scope of this was limited to releases occurring from 

the Purification, Dry Chemistry, Reduction and Recovery groups during documented plutonium 

production operations. In agreement with anecdotal evidence in several LASL documents, this analysis 

suggests that the bulk of plutonium releases occurred from the Recovery group, a result of open-air 

processing with minimal protection. Emissions resulting from the addition of hydrogen peroxide and 

from boiling of plutonium nitrate solutions were likely to have been particularly severe. This work 

resulted in a preliminary source term estimate of about 0.4 Ci (median) from processes that were 

included. This estimate is associated with a high degree of uncertainty, and true releases may have been 

in excess of 1 to 1.5 Ci. The preliminary 95th percentile value is about 1.05 Ci. The uncertainty is these 

estimates is mainly due to the relatively sparse and marginally relevant experimental data. If further work 

on estimation of early airborne plutonium releases from Los Alamos operations is undertaken, a portion 

of the work should be aimed at obtaining additional experimental data to support this estimate and 

reducing its uncertainty. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4 4-17 

NaOH

Simmer

Purification

Supernatants

1,4,6 Hydroxide Precipitation

T T

To Waste

Tank

T

Purification

Supernatants

2,3

1. Sulfate Reduction2. Hydroxide Precipitation

T

NaOH

SO2

T

To Waste

Tank

T

F

F

Acetate

T

HNO

1. Dissolved in nitric acid2. Precipitated with acetate

3

T

Filtrate

Recycled

T

F

Simmer

Sparge

T

Acetate

Wash

Dissolved

in HNO3

T T

To PeroxideProcess

Acetate

HNO3

T

F

= “Transfer” Release= “Filtration” Release

NaOH

Simmer

Purification

Supernatants

1,4,6 Hydroxide Precipitation

T T

To Waste

Tank

T

Purification

Supernatants

2,3

1. Sulfate Reduction2. Hydroxide Precipitation

T

NaOH

SO2

T

To Waste

Tank

T

F

F

Acetate

T

HNO

1. Dissolved in nitric acid2. Precipitated with acetate

3

T

Filtrate

Recycled

T

F

Simmer

Sparge

T

Acetate

Wash

Dissolved

in HNO3

T T

To PeroxideProcess

Acetate

HNO3

T

F

= “Transfer” Release= “Filtration” Release

Fig. 4-14. Flow diagram of recovery release mechanisms during recovery of plutonium from residual purification supernatants 
4-18 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4

NH NO 4 3

NH OH 4

Crushed MgO

crucible and 

reduction slag

TS T

Simmer HNO3

Dissolved in 16 N 

refluxing nitric acid 

(no condenser for 

first 30 min)

Precipitation 

in two 30 L 

battery jars

T

To Waste

Tank

T

F

T

NaOH

1. Dissolved in HNO32. Precipitated with NaOH

HNO3 Simmer

T

To Waste

Tank

T

F

Dissolved

in HNO3

T T

HNO3 To

PeroxideProcess

NH NO 4 3

NH OH 4

Crushed MgO

crucible and 

reduction slag

TS T

Simmer HNO3

Dissolved in 16 N 

refluxing nitric acid 

(no condenser for 

first 30 min)

Precipitation 

in two 30 L 

battery jars

T

To Waste

Tank

T

F

T

NaOH

1. Dissolved in HNO32. Precipitated with NaOH

HNO3 Simmer

T

To Waste

Tank

T

F

Dissolved

in HNO3

T T

HNO3 To

PeroxideProcess

Plutonium nitrate 

solutions from all 

other recovery 

processes

T

To Waste

Tank

T

F

T

Peroxide 

Precipitation

(effervescence)

Dissolved

in HNO3

T T

HNO3

Plutonium nitrate solutions 

boiled over steam bath to 

reduce volume

Boiling

Concentrated 

plutonium nitrate 

“syrup” sent to 

Purification

30% HOOH Boiling

Plutonium nitrate 

solutions from all 

other recovery 

processes

T

To Waste

Tank

T

F

T

Peroxide 

Precipitation

(effervescence)

Dissolved

in HNO3

T T

HNO3

Plutonium nitrate solutions 

boiled over steam bath to 

reduce volume

Boiling

Concentrated 

plutonium nitrate 

“syrup” sent to 

Purification

30% HOOH Boiling

Fig. 4-15. Release mechanisms associated with plutonium recovery from reduction slag and crucibles. “T” = “Transfer” release mechanism 

(liquid); “TS” = “Transfer” release mechanism (solid powder); “F” = “Filtration” release mechanism; “Simmer” = “Simmering” release mechanism 

Fig. 4-16. Release mechanisms associated with the final recovery processes involving precipitation ofplutonium nitrate with hydrogen peroxide 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4 4-19 

Indoor Measurements of Airborne Radioactivity as a Source of Information about 

Plutonium Releases from D Building during World War II 

One of the major operational areas from which plutonium releases were unmonitored was D-Building 

operations from 1943 until 1954. D Building was the site of the process development, production of the 

plutonium components of the early nuclear weapons, analytical chemistry operations, and metallurgical 

research and development. Although major plutonium component production activities were transferred 

to new processing facilities at DP West Site in late 1945, D Building continued to be an active and 

expanding facility until the Chemistry and Metallurgical Research (CMR) Building at TA-3 became 

operational around 1953. 

As D Building was the first facility to process plutonium in visible quantities and fabricate weapon 

components, many environmental safety and health practices considered routine today had not been 

developed. Work that today would be carried out in glove boxes with multiple stages of HEPA filtration 

on the exhaust was instead conducted in open hoods or on laboratory benches. Working conditions 

experienced after multi-gram quantities of plutonium began to arrive at Los Alamos in late 1944 rapidly 

deteriorated. In May of 1945, Wright Langham made a trip to Chicago to describe what steps were being 

taken at Los Alamos to protect the workers, including the recently developed monitoring methods 

utilizing bioassay. The push to develop and test the implosion device was considerable until the war was 

successfully concluded. 

Although LAHDRA team members were unable to locate any stack monitoring records for D Building for 

any portions of its operational period, workers at Los Alamos frequently took measurements of the 

airborne concentrations of plutonium in various rooms and locations around D Building. From these 

concentrations, estimated room volumes, ventilation rates and some other assumptions, a lower bound 

estimate of plutonium releases can be made. This estimate must be considered a lower bound for several 

reasons. A large portion of releases apparently occurred from operational activities conducted in hoods, 

glove boxes, and other enclosures. Releases of the contaminated air in laboratories would be expected to 

be small compared to the unmonitored releases from work performed in laboratory hoods and other 

primitive confinement devices that exhausted directly to the environment via roof-top vents. Those 

releases are the subject of a separate analysis. Also, there were no measurements made during the highly 

problematic startup period with larger quantities of plutonium, roughly from December 1944 to August 

1945. The measurements that were reported were made after the end of the war and after efforts were 

made to improve operational conditions within D Building. Finally, the rooms that had plutonium 
4-20 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4

measurements reported had results for less than 14% of all months. Many had only a few measurements 

during the entire period. 

The monthly reports listed average (and at times, maximum) values recorded over the month. The 

reporting of data clearly separated rooms that housed enriched uranium activities from those that housed 

plutonium operations, and the room assignments do not appear to have been interchanged significantly 

over time. This separation of uranium and plutonium operations must have been intended to simplify the 

control and measurement of contamination and was later continued at DP Site. 

Measurements were made in 116 unique areas within D Building. Some were rooms with the same 

number but differing letters (such as D-116 and D-116A) and other areas were hallways, change rooms, 

attics, and conference rooms. One might have had a total of 11,832 room-months of measurements (102 

months times 116 rooms); however, a total of only 1,616 monthly measurements were reported for the 

entire time period that started in August 1945. 

The release of plutonium over time for the room air exhausted was calculated by the LAHDRA team 

using the following assumptions: 

• 25% of room air volume is contaminated (heuristic estimate) 

• 30 air changes per h (based on interview with LANL staff) 

• Room Height = 10 ft for all rooms 

• Detector intrinsic efficiency of 80% 

• Filter Burial Factor of 1.602 (LANL has suggested a value of 2, not yet incorporated into this part 

of the study) 

• Counting Geometry Factor of 2 

The last three assumptions result in a total factor of 4.005 for the conversion of air sample counting 

results from counts per minute per liter (“c/m/l” or c/min/L) to disintegrations per minute per liter 

(“d/m/l” or d/min/L). 

The following equations were used to estimate the total release in a month for a given room: 

(d/min/L) = (c/min/L) × 4.005 

(d/min/h) = (d/min/L) × (room volume) × 0.25 of room air contaminated × 30 air changes h-1

(d/min released in a month) = (d/min/h) ×(d/month) × 24 h d-1

(Ci released) = (d/min released) / (3.7×1010 d s-1 Ci-1 × 60 s min-1) 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4 4-21 

Room air concentration data were compiled from the CMR-12 monthly reports into a spreadsheet. Room 

volumes were calculated based on LANL drawings of D Building. For areas with no defined volume, 

such as hallways, the volume of the section of hallway immediately adjacent to a laboratory was used 

(with a further reduction associated with the assumption that only 25% of that volume is contaminated). 

At present, the limitation of the contamination to 25% of the room air and also to a small section of 

hallway is felt to be non-conservative and produces a lower bound for the calculated releases. 

To emphasize the degree of non-conservatism in this estimate, in 1948, LANL began to better understand 

the nature of releases from D Building and glove boxes. In a study published in 1948, three rooms in D 

Building were subjected to air sampling for a little more than one year (Kennedy 1948). These rooms 

were used for processes that are not considered in the earlier section of this Chapter entitled “Release 

Estimates for D-Building Plutonium Processing.” They included Room 134, which was used in 1947 for 

preparation of plutonium alloys and samples. The air in this room would have released 1.5 mCi of 

plutonium in 1947 with the room air model assumptions given above. The releases to room air comprise 

a small fraction of the total plutonium released, since many of the operations were conducted in dryboxes. 

The plutonium released to room air largely came from transfers of material through the room to other 

boxes and from handling the material in the open. Releases from the dryboxes during grinding and 

polishing to prepare metallurgical samples for analysis were unmeasured and were another significant 

source of releases. 

As mentioned above, the monthly reports yielded a total of 1,616 data points from 116 rooms over 102 

months. This means that over 14% of the cells in the spreadsheet have values. All the data in a given 

year was compiled into a distribution and tested. The data for each year followed a log-normal 

distribution, with no year showing a smaller residual than 0.93. These distributions could be used, if 

further evaluation of D-Building releases is undertaken, to stochastically estimate air concentrations for 

rooms each month for which no measurements were reported. 

The sum of estimated releases over all months with reported measurements is 0.0109 Ci of alpha emitting 

radioactivity. Recall that this calculation is a partial representation of D-Building releases. In order to 

account for the rooms each month that have no results reported, additional assumptions must be made. 

This memo considers two possible approaches: 

• One method would be to simply assume that the unmeasured rooms have the same average 

contamination as the average measured room. Using this assumption, a value of 0.08 Ci is obtained. 

This method essentially increases the total estimated for sampled rooms by a factor of the total of 

11,832 room-months divided by 1,616 reported room-months. 
4-22 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4

• Many rooms have low concentrations reported. An alternate approach is to assume that the average 

measured concentration in a given room is constant for that room. Under this assumption, a total room 

air release of 6.12 Ci is obtained. There are rooms with high concentrations and few measurements 

that result in the larger release estimate under this approach, which assigns higher values to 

unmeasured periods than the average of measurements across all rooms. 

This range of estimates (from 0.08 to 6.12 Ci) does not include the troublesome startup period of DBuilding operations. Although this startup period represented 8% of the 102 months for which limited 

monitoring data are available, improvements in confinement devices might easily have afforded a factor 

of 10 reduction in air concentrations in a given laboratory by the time monitoring began. Thus, the early 

8-month period during which multi-gram quantities of plutonium was being processed might have been 

an important period for environmental releases that this preliminary assessment does not address. 

TA-21 (DP Site) Historical Plutonium Processing— DP West 

In January 1945, a serious fire that broke out in C Building within the Original Technical Area raised 

concerns about the possibility of a fire in D Building. This, plus a dramatic increase in the amounts of 

plutonium handled in D Building and concerns about the need to house plutonium and polonium safely, 

led to planning of new facility to be called DP Site and later TA-21. DP West took over the plutonium 

production functions of D Building. Most DP Site facilities were constructed in 1944-1945, and the 

necessary process equipment was installed during this time as well. Operations appeared to have started 

near the end of November 1945 (Meyer and Schulte 1944-1956). 

The primary functions of DP West were to: 1) produce metal and alloys of plutonium and other 

transuranic elements from nitrate solution feedstock; 2) fabricate these metals into precision shapes; 3) 

provide and install protective claddings; 4) measure the chemical and physical properties of these metals 

and alloys; and 5) recycle scrap or materials used in experiments (Valentine et al. 1982). 

Fig. 4-17 shows the early layout of DP West (Christenson and Maraman 1969). Photos of DP West are 

shown as Fig. 4-18 and Fig. 4-19. Buildings 2 and 3 housed wet chemistry processes, and Buildings 4 

and 5 housed dry chemistry processes. Building 12 was the main filter building for exhausted air. 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4 4-23 

1 2 3

5

Los Alamos Canyon 

DP Canyon

Building 12 

Exhaust (filter building) 

ductwork Manifold 

Main stacks (4) 

4 

East entrance road, to Los Alamos townsite 

Fig. 4-17. Early DP West Site Building Layout and Main Functions

Fig. 4-18. DP West site, looking north, date unknown. Plutonium process buildings 2, 3, 4, and 5 are labeled, as are

the filter building (12) and associated ductwork, manifold, and stacks. From photo IM-9:15926 courtesy of LANL.
4-24 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4

Fig. 4-20 presents a flow diagram of process used in early DP West Site operations in processing of 

plutonium and production of atomic weapon components (Kennedy 1947). 

Following are summaries of the activities performed in each major building at DP West: 

• Building 2 (TA-21-2)– housed gloveboxes for dissolution and recovery of plutonium and storage of 

241Am wastes. The building housed a scrap incinerator, solvent extraction columns, and a liquidwaste loading area. On 30 December 1958, a criticality accident occurred in Building 2 South 

involving separated phases in a plutonium process tank. The operator (Cecil Kelley) died 36 hours 

later. 

• Building 3 (TA-21-3)– housed the oxalate precipitation operations. 

• Building 4 (TA-21-4)– housed some development laboratories for plutonium research from 1945 to 

1948 at which point the laboratories were converted to production areas for enriched uranium 

hydride. In 1960, the hydride equipment was removed so that a hot cell could be added for the 

examination of irradiated plutonium and enriched uranium fuel elements. In 1965, two glovebox 

lines were added to support the 238Pu metal production. The above programs were part of Rooms 401 

and 401E on the north end of the building (Valentine et al. 1982). Rooms 403, 404, 405, 406, and 

407 also had gloveboxes that were used for 239Pu and 238Pu metal preparation during these early years. 

Fig. 4-19. Primary buildings of DP West on 16 May 1947. Photo courtesy of LANL (IM-9: 05426)
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4 4-25 

Fig. 4-20. A flowchart of early plutonium processing operations at DP West Site (from Kennedy 1947)
4-26 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4

• Building 21 (TA-21-21) – was a vault for storage of uranium and plutonium metal. 

• Building 33 (TA-21-33) – housed research efforts into collecting additional plutonium from waste 

streams. 

• Building 150 (TA-21-150) – was built in 1963 as a plutonium fuels development building (Repos. 

No. 2344). This building was built next to Building 5. Some of the programs the building supported 

included: 1) the development of 238Pu heat sources for space electric power applications; 2) 

investigations of various ceramic materials containing plutonium for use in the Liquid Metal Fast 

Breeder Reactor (LMFBR) program; and 3) the development of 238Pu fuels for isotopic powered heat 

sources for powering artificial organs (Valentine et al. 1982). 

In an incident in DP West Building 150 on 7 October 1970, a sealed capillary broke, resulting in the 

release of a reported 10 ug of 238Pu up a vent. Resulting concentrations were estimated to be 2,800 

times the AEC maximum permissible concentration (MPC) for insoluble 238Pu. Air samples were 

analyzed from the DP fence line, near private housing just west of the west end of the airport runway, 

and at the airport terminal air particulate sampler. Maximum reported air concentrations were 

1.27×10-14

μCi mL-1 238Pu at housing near the airport runway and 0.29×10-14μCi mL-1 239Pu at the DP 

Site fence (Kennedy 1970, Meyer 1970). 

• Building 210 (TA-21-210) – housed additional research activities on the properties and uses of 

plutonium. 

DP West Air Handling and Stack Air Sampling 

Buildings 2, 3, 4, and 5 each had an intake air fan. The air was filtered and then distributed by a system 

of ducts that entered the rooms of the buildings at the ceiling. The exhaust air left the rooms by another 

system of ducts that lead into a large common duct located on the roof of each building. All dryboxes and 

hoods for each building were vented into this common exhaust duct (LAB-CMR-12-60). 

These common ducts converged into a large manifold in Building 12, where the air was supposed to mix 

to a uniform concentration. The air then passed through the precipitrons. The precipitrons were 

electrostatic units that used electric fields to ionize and capture particles. The air then passed through a 

single bank of American Air Filter Company type PL-24 filters (Christensen et al. 1975). The air was 

finally discharged by exhaust fans out of four stacks that were approximately 57 feet tall. In the early 

days of DP West, the exhaust air was sampled in the common exhaust ducts, the Building 12 manifold, 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4 4-27 

and in each stack. Modified “Filter Queen” vacuum cleaners were used to sample the exhaust air at these 

locations (Maraman et al. 1975). 

The DP West Site exhaust treatment systems were improved over the decades of site operations 

(Maraman et al. 1975). A single bank of HEPA filters was installed in the DP West Site’s combined 

process exhaust system in 1959. The process exhaust system was separated from the plant exhaust 

system at that time. As part of the work during 1959, a cleaning of the room exhaust plenum resulted in a 

spike in measured airborne releases. The room exhaust plenum was again cleaned in 1973, leading to 

another spike in releases. Two banks of HEPA filters were installed in the process exhaust system in 

1973, the same year in which a single bank of HEPA filters was installed in the room air exhaust system. 

More Recent Plutonium Processing 

In 1969, the decision was made to build a new facility, TA-55, the Plutonium Facility Site. Processing of 

plutonium and research on plutonium metallurgy are done at this site, which is also known as “PF Site.” 

Operations at TA-55 include processing and recovery of 239Pu from scrap materials, recycle, metal 

production, metal fabrication, and research & development. This was also the site of special isotope 

separation research. The SIS-III was designed to provide special plutonium isotopes for LANL weapons 

research. The site also has responsibility for manufacturing heat sources for weapons-related programs 

(Cochran et al. 1987). 

Plutonium has also been processed at TA-3, the new Core Area: [a.k.a. “South Mesa Site”]. The Lab’s 

main technical facilities moved here from TA-1 in 1953. Areas at TA-3 that likely involved plutonium 

processing include: 

• TA-3-29 Chemical and Metallurgical Research (SM-29) (has Wings 1-9). 

• TA-3-32 Cryogenics 

• TA-3-34 Cryogenics 

• TA-3-35 Press Building 

• TA-3-39 Technical Shops 

• TA-3-40 Physics 

• TA-3-65 Source Storage (SM-65) 

• TA-3-66 Sigma Complex 

• TA-3-102 Tech Shops (handles beryllium, uranium, lithium per Repos. No. 225) 

• TA-3-141 Rolling Mill 

• TA-3-184 Occupational Health 

• TA-3-216 Weapons Test Support 

• TA-3-700 Acid Neutralization and Pump Bldg (also known as SM-700). 
4-28 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4

As of 1969, the CMR Bldg, except for its Wing 9, was used for laboratory work on small quantities of 

uranium and plutonium. Effluents were filtered through Aerosolve 95 filters. Wing 9 contained hot cells 

handling irradiated uranium and sometimes plutonium. Effluents may also have contained mixed fission 

products including iodine. HEPA and charcoal filters were reportedly used for treatment. Filters were 

counted for both alpha and beta radiation. 

Stack FE-19 of the CMR Building serves the glove box processes and rooms on the south side of Wing 3. 

As of March 1980, the exhaust treatment system had a demister, one stage of M-80 prefilters, and one 

stage of American Air Filter Continental 2000 filters (that is, bag filters with published 85% efficiency for 

0.3 μm DOP). Prior to July 1976, the system included Aerosolve 95 filters. 

Since early 1974, FE-19 has been major source of plutonium at LASL (up to 99% of the total in 1980). 

Releases from FE-19 began to increase during Feb 1979, when two filters tore. During filter change-out, 

flow reversal sent 143 μCi of Pu up FE-20 stack (Stafford et al. 1979-1982). February 1980 testing 

showed FE-19 filters were only 29.3% efficient. The release from FE-19 from Jan 19 – Jan 26, 1979 was 

91 μCi, which was greater than the total release for this stack in 1978. 

Alpha activity in liquids flowing into the TA-50 waste treatment plant rose sharply in the years leading up 

to 1973 because of increased use of 238Pu at the SM 29 building in TA-3. Concentrations at times reached 

0.001 μCi/cc [pages from microfiche: TR7831, Envelope 51, dated 5/9/73]. 

References 

Borkowski R, Bunz H, Schoeck W. Resuspension of Fission Products During Severe Accidents in LightWater Reactors, KfK 3987. Karlsruhe, Germany: Kernforschungszentrum; EUR 10391 EN; 1986. 

Repos. No. 1584. 

Christensen E, Garde R, Valentine A. Demolition of Building 12, an old plutonium filter facility. Los 

Alamos, NM: Los Alamos National Laboratory; LA-5755; 1975. Repos. No. 2349. 

Christenson CW, Maraman WJ. Plutonium Processing at the Los Alamos Scientific Laboratory. Los 

Alamos, NM: Los Alamos National Laboratory; LA-3542; 1969. Repos. No. 2346. 

Cochran TB, Arkin WM, Norris RS, Hoenig MM. Nuclear Weapons Databook Series, Volume III: U.S. 

Nuclear Warhead Facility Profiles. New York, NY: National Resources Defense Council; 1987. 

Coffinberry AS. Later plutonium metallurgical research at Los Alamos. The Metal Plutonium; 1961. 

Cosandey JO, Gunther A, von Rohr R. Transport of salts and micron-sized particles entrained form a 

boiling water pool. Experimental Thermal and Fluid Science 27: 877-889; 2003. 

Duffy D, Fleming GB, Garner CS, Wolfe DL. Building D Plutonium Recovery Processes 11/2/1945. Los 

Alamos, NM: Los Alamos Scientific Laboratory; LA-443; 1945. Repos. No. 1574 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4 4-29 

Garner CS, Duffy D, Wolfe DL, Fleming GB. D-Building Plutonium Recovery Processes Los Alamos, 

NM: Project Y; LA-443; 1945. Repos. No. 1574. 

Hammel EF. Plutonium metallurgy at Los Alamos, 1943-1945: Recollections of Edward. F. Hammel. Los 

Alamos, NM: Los Alamos Historical Society; 1998. 

Hemplemann LH, Richmond CR, Voelz GL. A Twenty-Seven Year Study of Selected Los Alamos 

Plutonium Workers 1/01/1973. Los Alamos, NM: Los Alamos Scientific Laboratory; LA-5148-

MS; 1973. Repos. No. 4052. 

Kennedy J. Volume 8, Chemistry of Uranium and Plutonium. Chapters 5 through 7, Section B. Los 

Alamos, NM: Los Alamos Scientific Laboratory; LA-1017; 1947. Repos. No. 3085. 

Kennedy WR. Studies of Air-borne Contamination Resulting from Operations Handling Plutonium Metal 

and Plutonium Alloys Los Alamos, NM: Los Alamos Scientific Laboratory; LAMS-725; 1948. 

Repos. No. 1591. 

Kennedy WR. Memo dated 14 October 1970 Detailing Incident at DP West on 7 October 1970. Los 

Alamos Scientific Laboratory. 1970. Repos. No. 246. 

Knutsen JS. Release Estimates for D-Building Plutonium Processing. LAHDRA project draft work 

product. ChemRisk, Inc. 2007. 

Knutsen JS, Widner TE. Description of Plutonium Processing Apparatus and Procedures in D Building 

during World War II LAHDRA project draft work product. ChemRisk, Inc. 2007. 

Maraman WJ, McNeese WD, Stafford RG. Plutonium– health implications for man. Confinement 

facilities for handling plutonium. Health Phys 29: 469-80; 1975. 

Meyer DD. Memorandum dated 16 October 1970 entitled Report on Radioactivity Release, October 7, 

1970, at DP West 1970. Repos. No. 267. 

Meyer DD, Schulte HF. CMR-12 Monthly Reports. Los Alamos Scientific Laboratory. 1944-1956. 

Repos. No. 139. 

Mishima J, Schwendiman LC, Radasch CA. Plutonium Release Studies III: Release from Heated 

Plutonium Bearing Powders. Richland, WA: Pacific Northwewst Laboratory; BNWL-931; 1968. 

Site Y. 49 Interim Processing Program Reports 9/11/1945. Los Alamos, NM: Site Y; 1945. Repos. No. 

4662. 

Stafford RG, Ahlquist AJ, Dummer JE, Ortiz J, Cucchiara AL, Stoker AK. Information on plutonium 

emissions from CMR Building FE-19 stack, ambient concentrations, and resulting doses. 

Memoranda. Los Alamos Scientific Laboratory. 1979-1982. Repos. No. 512. 

Sutter SL, Johnson LJ, Mishima J. Aerosols Generated by Free Fall Spills of Powders and Solutions in 

Static Air. Richland, WA: Pacific Northwest Laboratories; NUREG/CR-2139 (PNL-3786); 1981. 

USDOE. DOE Handbook - Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor 

Nuclear Facilities; Volumes I and II. Washington, DC: U.S. Department of Energy; DOE-HDBK3010-94; 1994. 

Valentine AM, Garde R, Cox EJ. Los Alamos DP West Plutonium Facility Decontamination Project, 

1978-1981 Los Alamos, NM: Los Alamos Scientific Laboratory; LA-9513-MS 1982. Repos. No. 

2344. 

Wahl AC. Plutonium Purification in D-Building 2/22/1946. Los Alamos, CA: Los Alamos Scientific 

Laboratory; 1946. Repos. No. 1583. 
4-30 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 4

Wahl AC. Chemical purification of plutonium, Chapter 3 of Los Alamos Technical Series, Volume 8, 

Chemistry of uranium and plutonium. Los Alamos, NM: Los Alamos Scientific Laboratory; LA1016; 1947. Repos. No. 3084. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 5 5-1

Chapter 5: Reactor Development and 

Operations at Los Alamos 

When it was first established, Technical Area 2 (TA-2), also known as Omega Site, was used for both 

nuclear criticality experiments and as the location for the Water Boiler reactor. Assembly of the first 

Water Boiler (the LOPO model) began in late 1943. In April of 1946, nuclear criticality experimentation 

was relocated from TA-2 to TA-18 (Pajarito Site). Construction of the plutonium fast reactor 

(Clementine) began in August of that year, and from then on Omega Site was used primarily as the 

location for reactors for neutronics experiments and isotope production. Over its history, three reactors 

have operated at TA-2: the Water Boilers (three different versions), the plutonium fast reactor 

(Clementine), and the Omega West Reactor (OWR). No reactors have operated at TA-2 since the 

shutdown of the OWR in December of 1992. The Water Boiler was deactivated in June of 1974, and the 

Clementine reactor was deactivated in December of 1950 following four years of problematic operation. 

The Water Boiler Reactors 

[Much of the following was adapted from “Early Reactors” by Merle E. Bunker (Los Alamos Science, 

Winter/Spring 1983). Other references are as cited.] 

During the Manhattan Project, a reactor 

was needed for confirming critical mass 

calculations, measuring fission crosssections, and determining the neutron 

scattering and absorption properties for 

materials being considered for moderators 

and reflectors in the first atomic bombs. 

Enrico Fermi advocated the construction 

of a homogeneous, liquid-fueled reactor, 

using enriched uranium. Three versions 

were eventually built, all based on this concept. For security reasons, these reactors were all referred to as 

“water boilers.” The name was appropriate, since dissociation of the fuel solution would occur in the 

higher-power versions, giving an appearance of boiling. 

The first water boiler was assembled in late 1943 at Omega Site. At that time, the fuel for this reactor 

(14%-enriched uranium) consumed the Nation’s total supply of enriched uranium. Two machine gun 

posts were therefore placed at the site to ensure its security. The first water boiler was called LOPO (for 

Fig. 5-1. A view of Omega Site, TA-2, from above
5-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 5

low-power) because its power output was virtually zero. This allowed for a simple design and eliminated 

the need for shielding. The fuel for the LOPO was an aqueous solution of enriched uranyl sulfate. The 

fuel was contained in a one-foot diameter spherical shell of stainless steel, surrounded by a reflector 

consisting of beryllium blocks on a graphite base. Control and safety rods passed through the reflector 

assembly. The fuel solution (known as the “soup”) was pumped into the steel shell from a conical storage 

basin located beneath it. Since the system was intended for low power, no provisions for cooling were 

included. The LOPO achieved initial criticality in May of 1944. 

The purpose of the LOPO was to determine the critical mass of a simple fuel configuration and to test the 

water boiler concept. With these goals met, the LOPO was dismantled to make way for a second design 

that could be operated at a power level of up to 5.5 kW and thus serve as a neutron source needed for 

cross-section measurements and other studies. This second version was called the HYPO (for high 

power). The fuel solution was changed from uranyl sulfate to uranyl nitrate, and cooling coils were added 

within the shell. A tube passing through the shell (called the Glory Hole) was also added to allow for 

placing samples in the region of maximum neutron flux. The reactor was surrounded with a concrete 

shield. The HYPO began operation in December of 1944, and was used for many of the key neutron 

measurements needed in the early days of atomic bomb design. 

In March of 1951, significant modifications to the HYPO were completed in response to demands for 

higher neutron flux and more research capability. These modifications allowed the water boiler to operate 

at power levels up to 35 kW. This modified version of the HYPO was dubbed the SUPO. Modifications 

made in the conversion of the HYPO to the SUPO included: 

• Installation of additional cooling coils within the fuel vessel for greater cooling capacity. 

• A significant increase in the enrichment of the uranyl nitrate fuel solution, from 14% 235U to 

88.7% 235U. 

• The beryllium oxide portion of the reflector was replaced with graphite to allow for more rapid 

shutdown. 

• A gas recombination system was connected to the reactor vessel to eliminate the explosion hazard 

posed by the radiolytic dissociation of hydrogen and oxygen from the fuel solution. The water 

formed in the recombination chamber of this system was returned to the fuel vessel. 

To reduce the emission of short-lived radioactive gasses from the Water Boiler, a delay line was installed. 

Before the installation of the delay line, it reportedly could not be determined how much 131I was present 

because of masking by Rb-88. Charcoal samples reportedly showed that essentially no 131I was present 

before or after the delay line was installed [3/98 memo J. Margo Clark to Ken Silver]. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 5 5-3

The SUPO Water Boiler experienced a water leak into its moderator shield, and had to shut down in 1973. 

Its stack was found to be contaminated with 137Cs (Site Tour, 1998). Contamination in the reactor had 

migrated to the bioshield. SUPO was operated almost daily until its deactivation in 1974. Like its 

predecessors, it was used extensively for cross-section studies and other neutron measurements. 

However, it was also used for studying reactor physics (perturbation effects) and for biological research. 

Planning for Decontamination and Decommissioning (D&D) of the SUPO facility began in July of 1988. 

The physical decommissioning process was completed in April of 1990, with the facility (TA-2-1-122) 

subsequently being released to the Isotope and Nuclear Chemistry division (Montoya, 1991; LA-12049). 

The Plutonium Fast Reactor (Clementine) 

[Much of the following was adapted from “Early Reactors” by Merle E. Bunker (Los Alamos Science, 

Winter/Spring 1983). Other references are as cited.] 

The plutonium fast reactor was proposed and approved in 1945 as a high-intensity fission neutron source 

that could also be used to assess the suitability of plutonium as a reactor fuel. Since a fast reactor requires 

no moderating material, the reactor could be of small size. The site chosen for the fast reactor was 

adjacent to the water boiler building at Omega Site. Construction began in August of 1946, during which 

time the reactor was dubbed Clementine, after the song “My Darling Clementine.” The fuel for the fast 

reactor was in the form of small rods clad in steel jackets. The rods were installed in a steel cage through 

which the coolant, liquid mercury, flowed at a rate of approximately 9 liters per minute. Flow was 

maintained via an electromagnetic pump. The fuel cage was surrounded with a 6-inch thick natural 

uranium reflector, most of which was plated with silver to reduce corrosion. The uranium reflector was 

surrounded by an additional steel reflector 6 in thick, and finally by a 4-in thick lead shield. Reactor 

(reactivity) control was effected via insertion of uranium fuel rods into the cage – a positive reactivity 

control method as opposed to the negative reactivity control method typically used in reactors. 

Initial criticality of the fast reactor was achieved in late 1946, though its design power of 25 kW was not 

reached until March of 1949. During this interim period, measurements were made at low power, 

including determination of the neutron energy spectrum, reactivity effects, cross sections, etc. Changes in 

the control system were also made during this time as experience in the operation of a fast reactor was 

gained. In March of 1950, following nearly a full year of operation, the fast reactor was shut down to 

correct a malfunction in the operation of the control and shim rods. During this shutdown, a ruptured 

uranium rod was discovered and replaced. Operation resumed in September of 1950, and continued until 

late in December of that year when it was determined that a plutonium fuel rod had ruptured and released 

plutonium into the mercury coolant. The hazard created by this condition and the identification of serious 
5-4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 5

abnormalities in the uranium reflector prompted the decision to permanently shut down and disassemble 

the reactor. One of the lessons learned from experience with the fast reactor was that mercury was 

unacceptable as a coolant due to its poor heat transfer properties and other concerns. 

When Clementine was decommissioned, its parts were stored in a hutment at Area C, and are believed to 

have been subsequently buried there (Repos. No. 525). The disposal location of the mercury coolant is 

not known (per Repos. No. 525). 

The Omega West Reactor (OWR) 

[Much of the following was adapted from “Early Reactors” by Merle E. Bunker (Los Alamos Science, 

Winter/Spring 1983). Other references are as cited.] 

 

With the early demise of the plutonium fast reactor, a replacement was needed to meet the needs for 

neutron measurements for various laboratory activities. Evaluation of the options available at that time 

led to a conclusion that a design patterned after the Materials Test Reactor (MTR) at the Idaho National 

Laboratory was the most attractive. A reactor designed to use the MTR’s plate-type fuel elements, which 

had already undergone extensive testing, meant core design and licensing could be expedited. The 

conceptual design for the new reactor was completed by the end of 1953. The core was to sit at the 

bottom of a water tank 8 feet in diameter and 24 feet high. The reactor would be cooled by water flowing 

at 3500 gpm. The proposed power level was 5 MW, but the shield was designed so that a power level of 

10 MW could be tolerated. To save time and money, the reactor was built in the same room that had 

housed the plutonium fast reactor. 

The OWR reportedly got an exemption from 10 CFR 100 reactor-siting criteria. The OWR was a small, 

low pressure, low temperature research reactor. Natural convective circulation of the reactor pool water 

was reportedly sufficient to cool the reactor. The maximum credible accident that was assessed would 

release 822 Ci of 131I to the air, along with 10,900 Ci of other iodines, 168 Ci of 131Xe, and 153,000 Ci of 

other rare gases. Doses were calculated at a Residential Area (0.4 mi cross canyon), Skating Rink (1.9 mi 

up canyon), and State Road 4 (4.0 mi Down Canyon). Maximum doses calculated by LANL personnel 

for this accident were reportedly 57 rem to thyroid and 22 rem whole body at State Road 4. [”Potential 

Environmental Issues at Los Alamos Scientific Laboratory” c. Oct. 1979, Repos. No. 615]. 

Construction of the new reactor began in mid 1954. Initial criticality was achieved in July of 1956, and a 

few months later the Omega West Reactor (as it became known) was operating at 1 to 2 megawatts. 

[Repos. No. 2387 states that the OWR achieved initial criticality on June 29, 1956.] In May of 1966, new 

operating limits were established that allowed the maximum operating power level to be increased to 6.5 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 5 5-5

MW (LA-UR-93-579). A modification to the OWR’s cooling system allowed its maximum operating 

power level to be increased to 8 megawatts in August of 1967. The technical specifications for the OWR 

prescribed a Limiting Safety System Setting (LSSS) of 11 MW. The OWR’s safety limit was 14 MW 

(LA-UR-93-579). 

The OWR reportedly had an iodine-125 production loop, and at times the reactor was operated essentially 

around the clock on an “Iodine Production Loop schedule.” “OWREX” capsules were placed in the 

reactor (e.g., OWREX-5 insert, OWREX-8 insert around 1966). These capsules evidently contained fuel 

and sodium. Fission gas traps and sweep-gas monitor detected leaks of capsules on several occasions 

[e.g., LA-3582-MS]. 

The combination of an unusual occurrence that resulted in a challenge to a safety system and the 

discovery of coolant leaks in underground piping prompted the shutdown of the OWR in December of 

1992. The unusual occurrence took place on December 11, 1992 when human error resulted in the 

reactor power rising to an administrative control limit of 9.6 MW, prompting an automatic shutdown of 

the reactor. The investigation report compiled for this event identified three root causes for the incident, 

but drew an overall conclusion that conduct of operations at the OWR facility was inadequate (LA-UR93-579). The three root causes specifically identified in the report were task performance errors on the 

part of various personnel, inadequate procedures for removal of samples from the reactor, and inadequate 

procedures and policies for ensuring reactor control is not compromised in the event of off-normal 

conditions (LA-UR-93-579). 

In 1994, all of the fuel and control blades were removed from the OWR and the facility was placed in a 

safe shutdown mode (Burns et al., 1993; LA-UR-95-4294). Inspection of the fuel elements conducted 

during the defueling operation showed that no fuel damage had occurred. All coolant was drained from 

the reactor vessel. A preliminary characterization in support of planning decommissioning activities was 

conducted in 1995 (Burns et al., 1993; LA-UR-95-4294). 

The Omega West Reactor (OWR) operated routinely operated 120 hours a week during its first 16 years. 

Usage dropped off to around 40 hours per week thereafter until the reactor was permanently shut down. 

Research conducted at the OWR included: cross-section studies, measurement of weapon yields (via 

comparison fission counting), neutron radiography, condensed matter studies (via neutron scattering), 

testing of power reactor components, testing of power reactor fuels, tests of plasma thermocouples, 

neutron activation analyses, and radioisotope production. 
5-6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 5

The Omega Stack 

A memo from Hornberger to Hoffman dated 25 May 1945 (Repos. No. 510) describes the off-gas line 

from the Water Boiler (HYPO) and reports exposure rate readings made beneath and to the sides of the 

line. These readings are given in terms of the time in hours one would need to be at a location to receive 

an exposure equal to the daily limit at that time. The first part of the line (see Figure 5-2) is described as 

being hung on tree supports and ascending the canyon wall. The last half of the line had four points 

where it sagged to the ground. Breaks in the line were noted at 75 yards and 25 yards from its exhaust 

end. There is no mention of a stack. The memo includes a hand-drawn figure (Figure 5-2) showing the 

off-gas line relative to the Water Boiler building and the mesas north and south of Los Alamos Canyon. 

Los Alamos document LAMD-155-I, “Manhattan District History, Volume II,” states that 

“External radiation hazards [at LANL] were, for the most part, well controlled. However, arrangements 

for discharge of fission products from the Water Boiler were most unsatisfactory and represented a 

potential and serious health hazard. The gaseous materials were merely discharged near ground level at 

the top of the mesa just to the south of Los Alamos Canyon. Warning signs were inadequate and the area 

was accessible to any casual visitor. Intensities in excess of 50 r/hr were repeatedly measured near the 

discharge point when the boiler was in operation.” 

Fig. 5-2. Sketch of the Omega Site off-gas line 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 5 5-7

Repos. No. 510 includes a memo from Blackwell and Littlejohn to Hempelmann dated April 24, 1947 

reporting their discovery that the offgas line from the Water Boiler (HYPO) was “shattered” at about 100 

feet prior to the “outlet” (stack), which was located in the top of a pine tree. It is surmised that the line 

became brittle from the off- gas and was broken due to swinging caused by recent high winds. 

In later years, a 150-ft tall stack on South Mesa was used to ventilate the OWR thermal column region 

and experiment. The flow rate in this stack was reportedly 880 ft3 min-1. Approximately 600 Ci of 41Ar 

was reportedly discharged per year [Repos. No. 645]. In 1968, a charcoal filter was added in the vent line 

from the OWR surge talk to the 150-ft stack [Repos. No. 648]. 

The original stack for OWR effluents was also described as a “flexible pipeline” that ran up the mesa and 

was attached to a tree. Exposures to a nearby “Trailer Village” were a concern [Repos. No. 510]. This 

original effluent line was Tygon tubing that was laid on the ground or draped on trees. It led to a pipe that 

was fastened to a pine tree. Eventually a buried stainless steel line and a stack were put into place. 

Repos. No. 177 includes a memo from D. D. Meyer to D. Ritter (ENG-4) dated June 11, 1957 that 

requests removal of the barbed wire exclusion fence that kept people 50 feet or so away from the Omega 

stack. It also states that the “old” Omega stack is still located in the top of a dead tree just outside the 

fence surrounding the current stack. It is requested that the old stack be taken down and sent to the 

“contaminated waste pit.” A second memo included in Repos. No. 177 (from D. D Meyer to Carl 

Buckland), also dated June 11, 1957; states that P-2 plans to connect the off-gas system for the OWR to 

the existing system for the Water Boiler (SUPO). Per Repos. No. 2414, this action was completed 

between September 20, 1957 and October 20, 1957. 

A charcoal filter was installed in the vent line for the OWR surge tank air space in 1968 (Repos. No. 648). 

The filter was installed as a precaution against a large radioiodine release that might otherwise have 

occurred in the event of a fuel element or experiment failure. 

Hankins (1963) describes the Omega stack as being 150 feet long and having an inside diameter of 8 in. 

The 2 inch (inside) diameter vent pipe from the reactor to the stack was 1100 ft long. The vent pipe 

included a settling tank and two water traps to collect water that condensed out of the effluent. The delay 

time of gas in the vent pipe was originally 2.3 d, but the addition of the vent line from the OWR cut this 

time to about 8 to 10 hours. The effluent in the vent pipe flowed to the stack at a rate of about 100 to 200 

cm3

 min-1, resulting in a dilution factor of about 100,000 in the stack. The stack flow rate was measured 

to be 845 ft3

 min-1 at a velocity of 2400 ft min-1. 
5-8 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 5

Per Hankins (1963), the combination of the recombiner, the long length of the vent pipe, and the low flow 

rates resulted in the particulate component of the effluent consisting of very small particles. It is reported 

that 65% were less than 0.05 μm, 93% were less than 0.1 μm, and none were larger than 1.0 μm. 

A timeline of events of operational significance for Omega Site reactors is presented as Figure 5-3. 

LAPRE I and LAPRE II

The Los Alamos Power Reactor Experiment (LAPRE) explored the use of a homogeneous reactor fuel 

consisting of highly-enriched UO2 (93.5% 235U) dissolved in 95% phosphoric acid. Such a reactor system 

was thought to show promise for portable power sources for military applications if a method for 

containing the highly-corrosive fuel solution could be found. Consequently, two test reactors (LAPRE I 

and LAPRE II) were constructed and operated at Ten Site (TA-35) by K-division personnel between 1955 

and 1960. LAPRE I was located in one of the hot cells of the main laboratory building. LAPRE II was 

located outside the main building in an underground enclosure tank. The purpose of the LAPRE I reactor 

experiment was to study the use of phosphoric acid solutions of uranium for a high-temperature reactor 

fuel in a simple, compact design in which the reactor core and the heat exchanger were contained in a 

single vessel (LA-2292). Protection of the reactor internals from the highly-corrosive fuel solution was 

supposed to have been achieved by coating the exposed surfaces with a thin layer of gold. While it was 

known that the problem of pinholes in the gold plating could not be completely eliminated (despite the 

use of multiple layers of gold), it was thought that the corrosion rate of the stainless steel under a pinhole 

in the plating would be tolerable (LA-2292).

The first critical experiments with LAPRE I began on February 15, 1956 (LA-2292). The reactor power 

was raised to a level of 20 kW and held there for five hours. Radioactivity was then detected in the steam 

line, and shortly thereafter criticality could not be maintained without dropping the temperature. The 

experiment was terminated with the fuel being transferred to an external tank. After nine days, the reactor 

was disassembled to determine the cause of the failure. It was found that some of the gold plating on the 

heat exchanger tubes had been damaged during assembly of the reactor, which allowed the hot fuel 

solution to come into direct contact with the stainless steel tubing. The fuel solution corroded several of 

the tubes, prompting failure. The corrosion rate observed was unexpectedly high relative to what had 

been predicted on the basis of laboratory tests (LA-2292). Chemical attack was also noted at 

imperfections in the plating of the vessel and the boron poison can (LA-2292). 
DRAFT FINAL REPORT OF CDC’s LAHDRA Project- Chapter 5 

Figure 5-3: Timeline of Operational Events for Omega Site Reactors

January 1943 January 1960

May 1944

LOPO initial

criticality

Dec 1944

HYPO begins

operation

(max. power = 5.5 kW)

Mar 1951

SUPO begins

operation

(max. power = 35 kW)

January 1960 January 1977January 1977 January 1994

Jun 1974

SUPO

deactivated

Dec 1946

Clementine initial

criticality

Mar 1949

Clementine reaches

design power (25

kW)

Dec 1950

Clementine

deactivated

Jul 1956

OWR initial

criticality

May 1966

OWR max.

operating

power raised from

5 MW to 6.5 MW

Aug 1967

OWR max. operating

power raised to 8

MW

Dec 1992

OWR scram

prompts

deactivation

Apr 1990

SUPO D&D

completed
5-10 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 5

Since the failure of LAPRE I was not due to the reactor itself, components were repaired or replaced as 

thought necessary and a second attempt at operating the reactor was made (LA-2292). This second 

experiment was conducted on 15 October 1956. The reactor reached a power level of 160 kW and had 

been held there for approximately 2 hours when radioactivity was detected in the feed water and steam 

systems, prompting a shutdown. Activity in the steam line rose rapidly, resulting in dose rates of 300 mR 

h-1 in the control room (LA-2292). This was thought to be due to gaseous activity released from the end 

of the steam line and drawn into the building ventilation system (LA-2292). Post-mortem inspection of 

the reactor determined the failure was again due to the heat exchanger tubes having been eaten away by 

the fuel solution. Since construction of LAPRE II was already underway at this time, further work with 

LAPRE I was abandoned (LA-2292). 

LAPRE II utilized a different fuel solution than LAPRE I. This new solution had a lower vapor pressure 

than the LAPRE I fuel, at the expenses of less uranium solubility and thus the requirement for a larger 

vessel to achieve a critical mass. LAPRE II was also to make use of bonded components, in hopes of 

solving the failures associated with the protective gold plating. Construction of LAPRE II was begun in 

February of 1956 (Clark, 1960; LA-2465). The reactor was located in an underground enclosure tank on 

the south side of the main laboratory building at TA-35. This arrangement provided a prudent means by 

which to provide the necessary radiation shielding. The design thermal power of the reactor was 800 kW. 

The primary purpose of the LAPRE II experiment was to demonstrate containment of phosphate fuels 

through suitable corrosion protection techniques. 

Operation of LAPRE II was begun in February of 1959 and continued into May of 1959 (Clark, 1960; 

LA-2465). Full power operation was achieved on April 22, 1959. The fuel solution was kept in the 

reactor vessel at a temperature above 200 F for 46 days. A maximum temperature of 826 F was achieved. 

Like LAPRE I, LAPRE II experienced problems with the leakage of volatile fission products into the 

steam system. At full power, dose rates of several thousand R h-1 were present adjacent to the feed water 

heater (Clark, 1960; LA-2465). Though it could never be determined for certain, it was suspected that the 

leakage occurred via containment problems with the heat exchanger, ala LAMPRE I. Dismantlement of 

LAPRE II began on May 8, 1959 with the transfer of the fuel solution back to the storage tanks (Clark, 

1960; LA-2465). The LAPRE program was terminated in 1960. 

LAMPRE I 

The following was adapted from “Early Reactors” by Merle E. Bunker (Los Alamos Science, 

Winter/Spring 1983) except where otherwise noted: 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 5 5-11

The purpose of the Los Alamos Molten Plutonium Reactor Experiment (LAMPRE) program was to 

explore the issues associated with using plutonium fuel in fast breeder reactors using a reactor fueled with 

molten plutonium and cooled by molten sodium. While the original design of the LAMPRE I reactor 

called for a design power level of 20 MW, the researchers concluded that the knowledge base required to 

develop such a system was not yet sufficient. The design of the LAMPRE I therefore underwent 

substantial changes, going from a 20 megawatt system down to a 1 megawatt test reactor. The LAMPRE 

I core matrix was such that it could accommodate up to 199 separate fuel elements. Each element 

consisted of plutonium-iron fuel material in a tantalum thimble. The core matrix allowed several fuel 

element designs to be tested simultaneously. 

The 1 megawatt design power for the LAMPRE I allowed it to be placed in an existing building at Ten 

Site (TA-35). A gas-fired 2-megawatt sodium cooling loop was also included to gain experience with 

high-temperature sodium-to-water heat exchangers. LAMPRE I achieved initial criticality in early 1961 

and operated for several thousand hours thereafter. One of the problems encountered was corrosion of the 

tantalum fuel thimbles by both the fuel and the coolant. 

By mid 1963 LAMPRE I had achieved its intended purpose and was shut down. LAMPRE II, which was 

to be the 20 megawatt system first conceptualized for LAMPRE I, was never funded, with the AEC 

instead opting to pursue uranium-oxide-fueled reactors rather than plutonium-fueled systems. LAMPRE 

was in the Ten-Site cell adjacent to the one used for 140La separation. It used molten plutonium contained 

within dozens of tantalum capsules, located within a sodium-cooled cylindrical core region about 40 cm 

high by 44 cm diameter. The LAMPRE fuel was transferred to Wing 9 at TA-3 (LA-UR-79-3091). 

LAMPRE experienced three separate fuel failures during operation; official reports say that these fuel 

failures did not cause any operational problems. [LADC-5936, CONF-258-1 by Robert A. Clark and 

Review of LAMPP by Argonne NL (PRO-P-1; 4/20/66)] 

The Rover Program 

In 1955, the United States initiated a program to develop a nuclear rocket engine to be used in defense 

systems and space exploration (Koenig, 1986; LA-10062-H). The plan was to carry large payloads into 

deep space, by essentially passing hydrogen through a very high temperature nuclear reactor, where it 

would expand and be blasted out of the reactor at high velocity. Conducted with NASA, this program 

was called Project Rover. Los Alamos was given the roles of establishing the basic reactor design and 

leading the fuel development effort (Koenig, 1986; LA-10062-H). A series of test reactors were designed 

and built at Los Alamos prior to being tested at the Nevada Test Site. These reactors were intended to 
5-12 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 5

first demonstrate proof of principle, then to establish and test the requisite design considerations. In 1962, 

Rover was the second largest program at LASL. The Rover program was cancelled in January of 1973. 

The Rover reactors were developed by the Los Alamos Critical Experiments Group using the facilities of 

the Pajarito Site (TA-18). In general, each new Rover reactor was developed following the same basic 

progression. First, parametric studies were performed using the Honeycomb assembly to establish the 

appropriate dimensions. The design then proceeded to the mockup phase, where details for controls and 

internal structures were worked out. Finally, the completed reactors were assembled and checked out 

prior to being sent to NTS for testing. Adjustments were made if any deviations from specifications were 

noted during checkout (Paternoster and Kirk, 1991; LA-UR-91-2434). Each Rover program reactor 

developed at Los Alamos is listed in Table 5-1 below, along with the date the reactor was tested at NTS 

(Paxton, 1983; LA-9685-H). 

Table 5-1. Rover Program Reactors Developed at Los Alamos 

Reactor Date(s) Tested at Nevada Test Site 

Kiwi-A July 1, 1959 

Kiwi-A′ July 8, 1960 

Kiwi-A3 October 19, 1960 

Kiwi-B1A December 7, 1961 

Kiwi-B1B September 1, 1962 

Kiwi-B2A test cancelled 

Kiwi-B4A November 30, 1962 

Kiwi-B4D May13, 1964 

Kiwi-B4E August 28 and September 11, 1964 

Kiwi-TNT January 13, 1965 

Phoebus-1A June 25, 1965 

Phoebus-1B June 26, 1968 

Phoebus-2A June 26, 1968 

Pewee-1 November 21, 1968 

Pewee-2 test cancelled 

NF-1 (Nuclear Fuel Furnace) June 29 and July 12, 21, and 27, 1972 

Before shipment to NTS, the Kiwi-TNT reactor was operated at Pajarito Site beside the PARKA reactor 

(essentially a Phoebus 1 reactor set up as a critical assembly) to measure their interactions at various 

separating distances. A 1969 waste management plan says that the DP East facility processed new Rover 

fuel elements containing enriched uranium. Air from the exhaust systems handling radioactive materials 

was reportedly passed through HEPA filters. All four stacks from these systems were monitored but 

concentrations were below detectable levels [Repos. No. 113]. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 5 5-13

UHTREX 

The Ultra-High Temperature Reactor Experiment (UHTREX) involved the construction and operation of 

a test reactor to advance the technology of high-temperature, graphite-moderated, gas-cooled reactors. 

The reactor was constructed in the late 1960s at Technical Area 52, and operated for approximately one 

year before being shut down in February of 1970 (Salazar and Elder, 1993; LA-12356). The UHTREX 

was cooled by helium gas in a system consisting of a primary and a secondary loop, and a single heat 

exchanger. Gas pressure in the two loops ranged from 475 psi to 545 psi, with the secondary loop kept at 

higher pressure than the primary in case leakage occurred within the main heat exchanger (K-Division, 

1967; LA-3556 Revised). Under maximum conditions, the gas temperature at the core inlet was 1600 F, 

and the exit temperature was 2400 F (Salazar and Elder, 1993; LA-12356). The secondary loop coolant 

entered the heat exchanger at 200 F and exited at 1000 F (Salazar and Elder, 1993; LA-12356). A 

regenerative heat exchanger called the recuperator was used to re-heat the primary coolant on its way 

back to the core. The recuperator also served to lower the primary coolant temperature from 2400 F to 

1400 F prior to it reaching the main heat exchanger. The secondary loop rejected heat to the atmosphere 

in a building outside the main reactor building. This heat dump building housed finned tubes cooled by 

large fans. The reactor produced no power. The UHTREX utilized 93%-enriched uranium fuel in the 

form of small spheres of UO2 coated with 3 layers of pyrolytic carbon and bound in a graphite matrix (KDivision, 1967; LA-3556 Revised). Fuel for the UHTREX was fabricated at the CMR Building (KDivision, 1967; LA-3556 Revised). The UHTREX was designed with a rotating core that allowed the 

reactor to be fueled while operating. The design thermal power for the UHTREX was 3 MW. 

The UHTREX utilized a gas cleanup system on the primary coolant loop to remove fission products and 

outgases from the (unclad) fuel. The UHTREX reactor, primary cooling system, and the gas cleanup 

system were contained in a gas-tight secondary containment provided by the main reactor building 

(Salazar and Elder, 1993; LA-12356). The gas cleanup system consisted of metallic filters (to remove 

particulate matter), a copper oxide bed (to oxidize reducing agents), molecular sieve beds (to adsorb 

carbon dioxide and water), and water-cooled beds of activated carbon (to either trap volatile fission 

products or to delay fission gases to allow for radioactive decay) (K-Division, 1967; LA-3556 Revised). 

Delay times for the carbon bed were 1.2 h for krypton and 20 h for xenon. Under maximum conditions, 

13 kW of decay heat were produced in the charcoal bed. Tritium produced in the primary coolant via the 

3

He (n,p) 3H reaction accumulated in the cleanup system in the copper oxide bed and in the molecular 

sieve beds. This tritium was eventually discharged up the 100 ft high main stack during regeneration of 

the sieve beds (K-division, 1967; LA-3556 Revised). This process also resulted in the discharge of 

entrained fission gases (K-Division, 1967; LA-3556 Revised). 
5-14 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 5

Air from the secondary containment, the fuel handling and gas sampling areas, and the change rooms and 

other such potentially contaminated areas passed through absolute (HEPA) and activated charcoal filters 

prior to being exhausted up the main stack (K-Division, 1967; LA-3556 Revised). Stack releases were 

monitored via a Tracerlab model MAP-1B/MGP-1A combination gas and particulate monitor (KDivision, 1967; LA-3556 Revised). The particulate monitor utilized a moving filter and a plastic 

scintillation detector. The gas monitor utilized a sodium-iodide detector. A removable charcoal filter was 

located between the particulate and gas monitors to allow for periodic assay of radioiodine concentrations 

via gamma-ray spectrometry. The stack monitor did not provide for “real-time” radioiodine monitoring. 

Air from the control room, offices, laboratories, equipment rooms, and other such “clean” areas was 

exhausted through rooftop vents. The UHTREX facility was designed so that air flowed from clean areas 

to potentially contaminated areas. 

Spent fuel from the UHTREX was loaded into casks and transported by truck to Wing 9 of the CMR 

Building where it could be evaluated utilizing the hot cell facilities there (K-Division, 1967; LA-3556 

Revised). Liquid radioactive wastes were carried by contaminated waste lines to the TA-50 treatment 

facility. Decontamination and Decontamination (D&D) of the UHTREX site and facilities began in the 

late 1980s. All radioactively-contaminated solid waste was buried at the laboratory’s central waste 

disposal facility (TA-54) (Salazar and Elder, 1993; LA-12356). 

References 

Bunker, 1983. M. E. Bunker. “Early Reactors” In: Los Alamos Science, Winter/Spring 1983. 

Burns et al., 1993. Burns, M. L.; Hartnett, S. L.; Seguin, N. R. “Waste Minimization Value Engineering 

Workshop for the Los Alamos National Laboratory Omega West Reactor Decommissioning Project”, 

LA-UR-95-4294, February, 1996. 

Clark, 1960. R.A. Clark, “Los Alamos Power Reactor Experiment No. II: LAPRE II”, LA-2465, 1960. 

K-Division, 1967. “Ultra-High Temperature Reactor Experiment (UHTREX) Facility Description and 

Safety Analysis Report”, LA-3556 Revised, April, 1967. 

Koenig, 1986. Koenig, D. R. “Experience Gained from the Space Nuclear Rocket Program (Rover)”, 

LA-100062-H, May, 1986. 

LA-2292. “Los Alamos Power Reactor Experiment Number One: LAPRE I”, LA-2292, 1959. 

LA-UR-93-579. “Investigation Report: Investigation of the Omega West Reactor Scram, December 11, 

1992”, LA-UR-93-579, February, 1993. 

Montoya, 1991. Montoya, G. M. “Final Project Report TA-2 Water Boiler Reactor Decommissioning 

Project”, LA-12049, 1991. 

Paternoster and Kirk, 1991. Paternoster, R. R.; Kirk, W. L. “Critical Experiments and Reactor Testing in 

Support of the Rover Program”, LA-UR-91-2434, September, 1991. 

Paxton, 1983. Paxton, H. C. “A History of Critical Experiments at Pajarito Site”, LA-9685-H, March. 

Salazar and Elder, 1993, Salazar, M. and Elder, J. “Decommissioning the UHTREX Reactor Facility at 

Los Alamos, New Mexico”, LA-12356, 1993. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 6 6-1

Chapter 6: Accelerator Operations at Los Alamos 

During World War II, accelerators were used to determine the critical masses for each proposed atomic 

bomb design. Two Van de Graaff accelerators were acquired from the University of Wisconsin, a 

Cockcroft-Walton accelerator was “borrowed” from the University of Illinois, and a cyclotron was 

purchased from Harvard (Hoddeson et al., 1993). 

The machines supplied neutrons for studying the neutron interactions involved in an explosive fission 

chain reaction. This was important because these interactions had not been studied at all of the neutron 

energies relevant to a nuclear explosion., from which fast neutrons are emitted with no slowing down or 

“moderation” as had been the case in the early graphite reactors. The accelerators also supported the 

effort to find a way of preventing a “fizzle,” or predetonation, in the gun-assembled plutonium bomb. A 

circular electron accelerator called a betatron was later procured to obtain sequences of images of spheres 

of mock fission fuel as they were being imploded by surrounding high explosives (Reichelt, 1993, Los 

Alamos Science No. 21). 

During the postwar years, the emphasis was on building a foundation of basic scientific research with 

weapons applications. Three wartime accelerators were purchased and retained by the government– the 

Short Tank, the Cockroft-Walton, and the cyclotron. The Long Tank was returned to the University of 

Wisconsin, but was replaced by a high-energy Van de Graaff accelerator with a vertical configuration. 

The neutrons from that device and those provided by the Cockroft-Walton were used to study neutron 

interactions relevant to nuclear fusion. The old Harvard cyclotron was upgraded into a variable-energy 

cyclotron that was used to study the angular distributions of accelerated particles after they scattered off 

the nuclear of various target elements. (Reichelt, 1993, Los Alamos Science No. 21). 

Two electron linear accelerators (linacs) were later built to provide radiographs of the implosion process, 

in work that led to the 1963 construction of PHERMEX (pulsed high-energy radiographic machine 

emitting x rays). PHERMEX generates x rays by accelerating an electron beam onto a tungsten target, 

and the x-ray bursts are sent through model weapons at a remote blasting site to provide threedimensional images of imploding spheres. (Reichelt, 1993, Los Alamos Science No. 21). 

Relatively small accelerators that have been used at Los Alamos include: 

• W Building at TA-1 housed a Van de Graaff accelerator. Building W had 2 high-voltage 

electrostatic generators used to produce variable energy neutrons for cross-section measurements. 
6-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 6

Protons were accelerated, hit a target (usually lithium), producing neutrons. Some X rays were 

also produced. There were also hazards from neutrons and X rays. 

• TA-3 Building 16 housed a Van de Graaff accelerator (a.k.a. SM-16). On 24 May 1977, there 

was a release of up to 800 Ci of tritium from the Van De Graaff accelerator. [Repository Nos. 

593, 829] 

Accelerator Operations at Technical Area 53 

The largest accelerator facility at Los Alamos is the one that is housed at TA-53. Following is a list of 

acronyms that are used in the discussion of TA-53: 

LAMPF = Los Alamos Meson Physics Facility; WNR = Weapons Neutron Research Facility; LANSCE = 

Los Alamos Neutron Science Center; PSR = Proton Storage Ring; MeV = Million Electron Volt (energy 

unit); MAP = Mixed Activation Products 

The primary facility at TA-53 is a large accelerator complex originally called the Los Alamos Meson 

Physics Facility (LAMPF). The original sections of LAMPF were later renamed the Clinton P. Anderson 

Meson Physics Facility. LAMPF is a nominal 800 million electron volt (MeV), 1-milliampere intensity 

proton linear accelerator. Construction was started on LAMPF in 1968. On June 12, 1972, LAMPF first 

obtained a full energy beam. Originally constructed to study sub-atomic particles, today LAMPF serves 

as an accelerator generating intense pulses of neutrons (by sending the protons into targets of high atomic 

number such as uranium) for scattering research at the WNR and LANSCE facilities. The Proton Storage 

Ring is used to accumulate protons and provide a short duration pulse of protons for targeting onto 

uranium and other high atomic number targets for neutron production at WNR. 

Today, the complex is called the Los Alamos Neutron Science Center, and includes the linear proton 

accelerator, the Manuel Lujan Jr. Neutron Scattering Center, and a medical isotope production facility. In 

addition, the Accelerator Production of Tritium Project Office, including the Low-Energy Demonstration 

Accelerator, and R&D activities in accelerator technology and high-power microwaves are located at TA53. 

LANSCE Release Summary 

LANSCE airborne radionuclide releases consist of short-lived radioactive materials that have been 

activated from air. These radioactive materials are composed of particulates from activated dust in air 

and gaseous activation products from air constituent gases. Another source of LANSCE radionuclide 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 6 6-3

releases is the cooling water used for cooling accelerator components. Non-radioactive releases at 

accelerators include solvents, which are used in large volumes for cleaning vacuum components. 

LANL documents refer to the mix of short-lived materials as Mixed Activation Products (MAP). Some 

other acronyms seen in documents are G/MAP for Gaseous Mixed Activation Products and P/VAP which 

are Particulate Various Activation Products. These radioactive materials are produced when the proton 

beam from LAMPF is sent through air, or when a fraction of the proton beam is lost through interactions 

with accelerator components (such as targets). These interactions generate neutrons, which subsequently 

activate the air gases and the dust in air. 

Radionuclide releases from LANSCE occur in two ways 1) from the four stacks located in the facility 

which are monitored for both particulates with filters, and for gases with Kanne chambers and 2) via 

unintentional pathways of diffuse release via doors and other exit points. For some periods of time, these 

combined emissions are the source of the highest priority releases to the environment. The radionuclide 

releases reported at LANSCE are among the highest of all DOE operations nation-wide. The amount of 

radioactivity released from LANSCE increases proportionally as the power levels and beam-on time 

increase. Principal gaseous radionuclides constituents released were 11C (20 min), 13N (10 min), 

15O (2 min). A trace amount of 41Ar (1.8 h) was also released. The particulate releases are too numerous 

to mention and are only present in trace levels since these consist of activation products from dust in air 

or disintegrated target material. 

Cooling water that services accelerator components, including targets, also becomes radioactive, and also 

accumulates corrosion products from the target and magnet systems. This water has been released by the 

site after decay in concrete walled cooling water ponds that have bentonite clay on the bottom. The 

cooling water is held until no short-lived radionuclides are observed in the water, after confirmation 

measurements, the cooling water from these ponds is then released and becomes surface water. 

Prioritization of LANSCE Releases 

The releases from LANSCE are cataloged in detail by the LAHDRA team in a two calculations (O’Brien 

2003a and O’Brien 2003b). Results of the prioritization assessment for airborne radionuclides are 

presented in Chapter 17. The calculation of Priority Indices (PI) involves dividing the reported annual 

release by the maximum effluent concentration from 10 CFR Part 20. The result represents the volume of 

air required to dilute the releases to the maximum permitted value, and therefore permits comparisons for 

varying amounts of radioactive material from year to year based on the total quantities of air required to 

dilute the effluent. The maximum effluent concentration value used for MAP is from the International 
6-4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 6

Atomic Energy Agency (IAEA 1979) and was 2.0×10-7 μCi mL-1. The prioritization shows that LAMPF 

dominates site releases to air since the mid-1970s. 

 Detailed LANSCE Release Data 

The LAHDRA project team has spent many hours finding and reviewing LANSCE records. The project 

team has identified two key document resource centers within TA-53 that provide substantial quantities of 

historical effluent monitoring data for LANSCE. Those records cover operations from the early 1970s to 

the present. The locations are: 

• Building 3, Room 3R-4 (TA-53-3) - Radiological records that contain mostly exhaust stack and 

water monitoring data for radionuclides. 

• Another location for useful records is the operations group in Building 53. Management staff at 

the accelerator facility generally opted to retain large portions of their records for historical and 

operational purposes and has stored these records on-site at TA-53. 

Monthly and annual air emission reports from 1976 to the present have been located by the LAHDRA 

team. These reports also present backup information pertaining to how LANL staff performed and 

collected stack monitoring data and calculated air releases. In related reports, methods for calibration of 

Kanne “flow-through” ionization chambers and for stack measurements are presented. 

Probably the most appropriate method of estimating releases is to use the accelerator operation logs to 

obtain the milliampere-hours (mA-h) of beam operation, then to use the LAHDRA team’s Off-Site 

Releases (OSR) Database to obtain the curies released annually at TA-53. The accelerator logs were 

found by LAHDRA analysts and entered into a spreadsheet (LANSCE Effluents.xls) for 1976 to 1992. 

Periods of accelerator operation are called “cycles” and each cycle is given a sequence number. These 

data included operations during cycles 3 through 61. Data for cycle 1 and 2 were not found. Data for 

cycles above 61 are available, but were not captured. In the LANSCE Effluents spreadsheet, beam 

current was multiplied by beam-on time to calculate mA-hrs for the beam. These values were summed to 

yield annual values of beam time in mA-h (see Table 6-1). Curies per mA-h are plotted in Fig. 6-1. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 6 6-5

0.00E+00

5.00E+01

1.00E+02

1.50E+02

2.00E+02

2.50E+02

3.00E+02

3.50E+02

4.00E+02

1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993

Ci/m A -hr

Table 6-1. Compiled Annual Beam Current Data for LANSCE 

Year mA-h 

(from log books) 

Annual Activity in Curies 

(from OSR Database) Curies per mA-h 

1974 1.00E-08 

1975 1.00E-08 

1976 202.66 6.06E+03 2.99E+01 

1977 702.27 4.79E+04 6.82E+01 

1978 1,259.80 1.17E+05 9.29E+01 

1979 1,834.57 1.19E+05 6.49E+01 

1980 2,180.00 1.46E+05 6.70E+01 

1981 1,010.79 3.53E+05 3.49E+02 

1982 2,151.52 2.51E+05 1.17E+02 

1983 1,593.71 4.64E+05 2.91E+02 

1984 2,420.37 7.37E+05 3.04E+02 

1985 3,004.61 1.26E+05 4.19E+01 

1986 2,600.06 1.12E+05 4.31E+01 

1987 2,534.84 1.50E+05 5.92E+01 

1988 1,929.32 1.21E+05 6.27E+01 

1989 2,128.43 1.56E+05 7.33E+01 

1990 1,966.90 5.00E+02 2.54E-01 

1991 721.56 5.75E+04 7.97E+01 

1992 744.83 7.19E+04 9.65E+01 

1993 2.11E+02 

1994 5.04E+04 

1995 4.37E+04 

1996 1.14E+04 

Fig, 6-1. Ci/mA-h for LANSCE operations 1975-1993
6-6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 6

There were some columns in the beam operation logs that were not used in these informal calculations 

since it was not known how to apply them. One column was for “Duty Factor” and two contained 

additional beam information “Beam Current 2” and “Beam Hours 2”. From verbal conversations with 

LANL employees it was found that the “Beam Current 2” and “Beam Hours 2” were used only when the 

beam was run at one current for a certain amount of time and then was run for a second amount of time at 

a different beam current. Since there were not many times this information was supplied it was ignored 

for this informal calculation. “Duty Factor” was explained as having something to do with the pulsed 

nature of the output used sometimes during the operation. Since it was not know how to apply a 

correction factor for “Duty Factor”, the column was not used. 

In addition to point release estimates (i.e., exhaust stack releases) LANL began estimating non-point 

(diffuse) emissions in their annual release and dose estimates. Documents were found for 1993, 1995, 

1996, and 1997. The estimates of diffuse releases were 1,418 Ci, 716 Ci, 221 Ci, and 866 Ci for the years 

listed respectively. These quantities are approximately less than 10% of the annual airborne release 

values as shown in Table 6-1. The vast majority of these releases were estimated to be 11C. 

Repos. No. 1071 mentions that short-lived activation gases were not reported at LAMPF for the 1974 to 

1978 time frame. One of the documents abstracted (Repos. No. 441) refers to a letter to the AEC 

concerning LAMPF airborne emission in 1970, so limited operations may also have occurred prior to 

1972. 

The TA-53 data suggest that there are at least four stacks for which data are available. These stack 

designations include: FE-3 (North Stack, also called main stack in 1981); FE-4 (South Stack); FE-16; and, 

FE-2. The FE-3 fan serviced the main accelerator tunnel, and was terminated in 1980. The FE-4 fan was 

added in 1977. FE-3 and FE-4 have reported emissions primarily of short-lived air activation products 

such as: 11C, 13N, 15O, 41Ar, and 7

Be. FE-2 services the WNR, and was added in 1981. FE-16 services 

TA-53-1 D-wing, with releases reported for other longer-lived radionuclides such as 7

Be. 

Cooling water was released to floor drains that fed two 2,500-gal carbon steel tanks. These tanks were 

discharged to the cooling water ponds (Repos. No. 503). The magnitude of releases at LANSCE resulted 

in continuing studies to estimate the off-site impact. One such study was LA-11150-MS, which 

documented the releases and modeling of the releases for 1985 (Repos. No. 2145). Laboratory 

measurements have been found for lagoon and cooling pond waters, and for long-lived activity that can 

be collected on filtering media. The short-lived MAP was assessed with on-line monitoring and through 

TLDs located at various locations. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 6 6-7

Repos. No. 1556 discusses the diffuse releases from LAMPF for 1990, which were 0.21 Ci, a small 

fraction of the 120,000 Ci of short-lived gases that were reported. The diffuse emissions were comprised 

of longer lived nuclides (since the diffuse emissions are completely unfiltered) and a comparison of curies 

alone might be misleading, but the magnitude of diffuse emissions is clearly less significant than that of 

the primary release points. 

The LANL assessment of the impact of radioactive releases from TA-53 has changed in many ways over the years. 

Prior to 1991, the site assessed the releases taking credit for estimated occupancy and the inherent shielding 

provided by residences. In 1992, LANL was told by the USEPA that no credit should be taken for shielding and 

residency time factors (Repos. No. 713). This resulted in a change in methodology for projecting impacts from the 

releases. Care should be taken when comparing assessments reported by LANL for different periods. 

Conclusions Regarding LANSCE Operations 

LANSCE is an important major scientific system at LANL. Its operation is important to scientists and researchers 

from LANL and visiting organizations. Since its inception, LANSCE has been one of the major contributors to 

airborne releases to the environment. Fortunately, the radionuclides released are short-lived gases or trace amounts 

of particulates from diffuse emissions. Future iterations that are attempting to create an accurate source term for 

LANSCE should concentrate on applying the additional beam time corrections, applying the duty factor corrections, 

locating early operation info (cycle 1 and 2), and ensuring that the curie quantities in the OSR Database are 

complete and accurate so that Ci/mA-h can be calculated accurately for LANSCE. 
6-8 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 6

This page intentionally left blank. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 7 7-1

Chapter 7: Tritium Processing at Los Alamos and a 

 Screening Assessment of Public Exposures 

The benefits of incorporating tritium into nuclear weapons design was recognized early in the Manhattan 

Project. Facilities and processes for tritium production were a topic of discussion at LANL at least as 

early as 1944 (Allison 1944). By this time, tritium production efforts had already begun at the X-10 site 

(now the Oak Ridge National Laboratory) and there were discussions about large-scale tritium production 

taking place at Hanford. As of late 1945, LANL had installed equipment for the purification and assaying 

of tritium. The Lab’s CMR Division began using this equipment to supply tritium to groups within P 

Division and M Division in early 1946. A tritium collection system was being installed in the 

laboratories of Group P-4 as of March of 1946 (LASL 1946). It is unclear where these operations took 

place, but small quantities of tritium are reported to have been used in Buildings U, W, and Z in the 

Original Technical Area (TA-1). As Laboratory operations matured, significant quantities of tritium were 

released to the atmosphere from facilities in TAs 3, 21, 33, 35, and 41. In addition, tritium was used in 

some firing site (dynamic testing) activities, at TA-15 for example. 

Tritium Facilities at TA-3 

The three facilities responsible for the majority of atmospheric tritium releases from TA-3 were the 

Cryogenics Laboratory (Building SM-34), the Ion Beam Facility (Building SM-16), and the CMR 

Building (Building SM-29). Both the Cryogenics Laboratory and the IBF used tritium gas generated 

from uranium tritidea

 beds. 

The LANL Cryogenics Laboratory opened in 1955 and is reported to have released 28,000 Ci of tritium 

from 1976 to 1985 (Morgenstern and Hueske 1995). The Ion Beam Facility (IBF), which housed two 

Van de Graaff accelerators, began operating in 1951 (Loomis et al. 2005). The accelerators produced 

neutrons by bombarding tritium gas targets with charged particles. Atmospheric tritium releases for the 

IBF are reported to have been 14,000 Ci from the 1960s through 1992 (Morgenstern and Hueske 1995). 

The same reference reports a release of 11,000 Ci of tritium from the CMR Building from when it began 

operations in 1953. The asserted releases for these three facilities total 53,000 Ci. 

 

a A tritide is a hydride (a binary compound formed by the union of hydrogen and one other element) in which hydrogen is in the 

form of its 3

H isotope.
7-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 7

Tritium Facilities at TA-21

TA-21 has housed the LANL Tritium Handling Facility (THF) and the Tritium Systems Test Assembly 

(TSTA), as well as earlier tritium operations. The THF was also known as the Tritium Salt Facility 

(TSF). It was expanded in 1984, and subsequently became known as the Tritium Science Fabrication 

Facility (TSFF). The THF was activated December 5, 1974 as a replacement for obsolete tritide salt 

processing facilities at TA-35. It was located at DP East Site in Building TA-21-209. The THF consisted 

of a large dry box system and a gas purification system. Its purpose was to house processes involving 

metal tritides, specifically, tritium-bearing lithium salts. As of December 12, 1979 the THF had 

reportedly processed 3.8 million curies of tritium and had released 704.5 Ci to the atmosphere via its local 

stack (Nasise 1980). 

TSTA was a facility for the integrated testing, in full scale, of the processes and safety systems required 

for the reprocessing and recycling of plasma exhaust gas from a tokamak fusion reactor. The primary 

material handled was deuterium-tritium (DT) gas. Tritium was first introduced at TSTA on June 25, 1984 

(Jalbert 1985). 

Tritium appears to have been in use at DP West since at least the early 1950s. In 1952, J. B. Webber of 

LASL described sampling of effluent streams for tritium oxide from a beaker of tritiated water placed in 

various locations in DP West Room 326 (Webber 1952). By 1971, a tritium stack monitor had been 

installed for DP West Room 513 (Johnson 1971). 

Tritium Facilities at TA-33

TA-33 was established in 1947 as primarily a test site for atomic bomb initiators (Garcia et al. 2004). 

Dynamic testing activities took place there involving polonium and other materials. Shots were fired in 

underground chambers and at the surface. Large guns were used to fire test projectiles into berms. In the 

early 1950s, facilities were designed and built at TA-33 for the processing of tritium gas (Coffin 1971). 

The high pressure tritium gas facilities were housed in Building HP-86 and operated there until late 1990 

(Garcia et al. 2004). In addition to its function as a high pressure tritium pumping station, HP-86 also had 

laboratory areas for conducting tests of tritium gas systems and for material compatibility studies (Tuggle 

1983). HP-86 had a 75-foot stack as of late 1962, though apparently the stack height had increased from 

its original design (Deinken 1962). 

On an activity basis, HP-86 is believed to be the largest source of atmospheric releases of tritium at 

LANL. Coffin (1971) stated routine releases to the atmosphere were 2,000 to 6,000 Ci annually and that 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 7 7-3

60,000 Ci of gas had been released in ten separate incidents dating back 15 years. These accidental 

releases were in addition to routine releases associated with the evacuation of lines and vessels containing 

tritium gas and leakage from the gas system overall. The gas system consisted of a process system and a 

filling system, with the former used to mix and prepare gases for introduction into the latter (Holmes 

1965). The filling system was used to fill a desired container with tritium gas at a desired pressure. 

Coffin (1971) estimated the contributions from routine and accidental releases to the total atmospheric 

source term to be approximately equal. The LAHDRA document collection contains numerous 

references documenting accidental releases of large quantities of tritium gas at TA-33. 

Tritium Facilities at TA-35

The original tritium salt facility was located in the basement of Building 2 at TA-35. It was constructed 

in 1953 (Harper and Garde 1981) and was in use until 1974 when the tritium salt operations moved to DP 

East Site. The TA-35 tritium salt facility was decommissioned in 1979. The facility was used to handle 

lithium tritide salts containing kilocurie quantities of tritium. It consisted of two glovebox lines and 

associated equipment, and had its own exhaust stack (Harper and Garde 1981). Tritium operations began 

in 1955 (Storm 1972) and ended in 1979 with the decommissioning of the facility. Tritium releases from 

the TA-35-2 facility did not end when operations were relocated to DP East Site. Releases continued to 

be monitored and reported through the decommissioning process. 

The lithium tritide salts were received from Mound Laboratory in a powdered form and were processed 

and packaged at TA-35 for transfer to Group W-1 (Storm 1972). As of 1972, the frequency of the 

operation was 6 to 24 weeks per year. Water reacting with the salt compound would result in the release 

of tritium. This condition was exacerbated by the high moisture content of the glovebox cover gas and 

the use of water to clean some of the process equipment (Storm 1972). The fact the tritium was released 

through the water-salt reaction prompted Ellery Storm of LASL to conclude it was probably released in 

the oxide form. 

Tritium Facilities at TA-41

TA-41 was constructed in the early 1950s for weapons development activities (LANL 1988). It was built 

at the bottom of Los Alamos Canyon, approximately 300 feet below the mesa tops. A central exhaust 

system and stack were added in 1962. Prior to that time, process effluents were ventilated by local stacks 

and exhausts serving individual laboratories. TA-41 consists of a number of structures, including an 

underground vault for the storage of explosives and special nuclear material. The vault, designated 

Building W-1, is a reinforced concrete structure constructed by tunneling into the north wall of Los 
7-4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 7

Alamos Canyon. It was built in May, 1949 (LANL 1991). Materials stored in the W-1 vault included 

pressure vessels containing tritium gas. 

It is unclear when tritium operations first began at TA-41. LANL’s 1973 estimates of atmospheric tritium 

releases included estimates for TA-41 dating back to 1967 (LASL 1973). In 1976, LANL was evaluating 

locating a new tritium handling facility at TA-41 (Barnes 1976) to replace operations at the HP-86 facility 

at TA-33. It is not clear when these activities began, but it appears they continued until approximately the 

early 1990s. As of 1983, one of the primary activities at TA-41 was the building and testing of equipment 

and systems for the storage and transfer of high pressure gases, including tritium (Tuggle 1983). In 1992 

the Laboratory determined the cost associated with upgrading the TA-41 facilities to allow resumption of 

programmatic tritium operations involving quantities greater than 1,000 Ci was not justified (Erickson 

1993). Those operations were to be transferred to the Weapons Engineering Tritium Facility at TA-16. 

TA-41 was also used for plutonium operations, dating back to at least 1957 (Buckland 1957), and 

uranium. As of 1983 plutonium and uranium were handled only in sealed containers. Experiments with 

the containers were conducted inside double containment (Tuggle 1983). 

Other Tritium Facilities

As of 2001 the largest tritium inventory at LANL was held at the Weapons Engineering Tritium Facility 

(WETF) at TA-16. Originally constructed as a replacement for the tritium gas facilities at TA-33 (LANL 

1990), WETF houses research and development activities in support of nuclear weapons programs and 

inertial confinement fusion (DNFSB 2001). Consolidation efforts were at that time underway to relocate 

all of LANL’s tritium processing operations to WETF. WETF is a more modern facility than its 

predecessors and its tritium releases to the atmosphere are relatively small. Other LANL facilities that 

contribute to atmospheric tritium releases are waste treatment operations at TA-50 and operations 

involving tritium-contaminated weapons components at TA-55. There have also been limited tritium 

operations conducted at a gas boosting test facility housed at TA-9 (Tuggle 1983). With respect to 

environmental levels, a significant source of atmospheric releases of tritium oxide has been the Lab’s 

central waste disposal facility at TA-54. Buried, tritium-bearing waste materials result in atmospheric 

releases of tritiated water vapor via evaporation from the soil. These releases are evident on the local 

ambient air monitoring stations. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 7 7-5

Atmospheric Effluent Data for Tritium

LANL did not begin monitoring tritium stack releases until 1971. In 1973, the Lab prepared estimates of 

atmospheric releases for 1967 through 1970 based on accountability data (LASL 1973). There are no 

formal estimates of total tritium releases prior to 1967, though the LAHDRA document collection 

contains effluent monitoring and other tritium release data for some tritium facilities prior to 1967. How 

complete a picture this information might represent with regard to LANL’s total atmospheric tritium 

releases for the pre-1967 period is currently unknown. 

Earlier in the project, the LAHDRA team made a limited effort to compile tritium effluent data from its 

document collection into a database. Specifically, the focus was on the Lab’s formally reported tritium 

releases for the period from 1967 forward. These data were entered into a database known as the Off-Site 

Releases (OSR) database. The OSR database was an internal tool used by the LAHDRA project team to 

support prioritization of historical radionuclide releases from LANL. 

Table 7-1 summarizes the atmospheric release data for tritium in the OSR database for TAs 3, 15, 21, 33, 

35, and 41 for 1967 through 1991. After 1991, the tritium effluent records used to populate the OSR 

database began reporting releases on a consolidated basis, that is, releases from multiple TA were 

combined and reported as a single value. Regardless, the data for the years included in Table 7-1 are 

believed to encompass the periods of the largest airborne tritium releases from the selected TAs since 

1967. In addition, the documents that have been reviewed indicate that these facilities represented the 

largest contributors to atmospheric tritium releases. In Table 7-1, years for which no data were reported 

are denoted by “– ”. This notation differentiates from the values of 0 for several years for which the 

database currently shows a release of zero curies. 

As the primary charge of the LAHDRA project was information gathering, only limited resources could 

be dedicated to source term evaluation in support of screening for potential health risks. Thus, the data in 

the OSR database are known to be incomplete with respect to the totality of tritium release data embedded 

in the LAHDRA document collection. As an example of the possible magnitude of data not yet captured 

in the OSR database, compare the total release for TA-3 shown in Table 7-1 (35,414 Ci) with that asserted 

in 1995 by Morgenstern and Hueske (53, 000 Ci). The latter, which includes releases for the period prior 

to 1967, exceeds the total from the OSR database by a factor of about 1.5. It should be noted than none of 

the release totals cited here have been independently verified by the LAHDRA team. All values have 

been used as reported in the available reference material, without adjustment. 

 
7-6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 7

Table 7-1. Airborne Tritium Release Data for Selected TAs from the OSR Database (Ci) 

Year TA-3 TA-15 TA-21 TA-33 TA-35 TA-41 Total 

1967 872 3,590 - 11,284 - 12,168 27,914

1968 10,382 - 23 5,512 - 15,782 31,699

1969 172 4,500 3 20,098 - 9,750 34,523

1970 - 11,000 - 670 25,000 438 37,108

1971 - 2,660 - 4,100 3,100 320 10,180

1972 - 1,796 - 2,100 2,500 110 6,506

1973 - - 4 3,880 2,464 118 6,466

1974 - - - 5,916 1,400 - 7,316

1975 22 - 306 3,478 2,394 - 6,200

1976 - - 95 1,349 1,657 - 3,101

1977 400 - 133 36,950 786 - 38,269

1978 100 - 72 17,780 676 - 18,627

1979 3,015 - 95 10,470 1,300 143 15,024

1980 5 - 106 6,965 25 414 7,515

1981 899 - 108 6,085 - 126 7,218

1982 1,938 - 169 13,600 - 130 15,837

1983 2,277 - 180 4,410 6 974 7,847

1984 1,793 - 802 7,110 206 4,780 14,691

1985 2,119 - 367 4,870 5 1,270 8,631

1986 1,228 - 448 6,660 48 1,320 9,704

1987 851 - 596 1,000 155 470 3,072

1988 8,350 - 528 - 118 1,730 10,726

1989 291 - 455 1,770 18 11,600 14,134

1990 496 - 439 854 0 4,440 6,229

1991 205 - 334 254 0 3,840 4,633

Total 35,414 23,546 5,262 177,165 41,858 69,923 353,168

To ensure a conservative approach to screening, and to account for the fact the tritium release data in the 

OSR database were incomplete, the maximum annual atmospheric tritium releases for each of the selected 

TAs were compiled. These are shown in Table 7-2. 

Table 7-2. Maximum reported airborne tritium releases from LANL

Technical Area Maximum Release (Ci) Year 

3 10,382 1968 

15 11,000 1970 

21 802 1984 

33 36,950 1977 

35 25,000 1970 

41 15,782 1968 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 7 7-7

For screening purposes, the maximum values should at a minimum be representative of LANL’s 

atmospheric tritium releases for the period 1967 forward, if not bounding in the case of the earlier data 

derived from accountability data. For the principal contributors to atmospheric tritium releases, all but 

two of the maximum values were from the period prior to the onset of stack monitoring, that is, they were 

derived from accountability data. Such estimates are typically conservative with respect to the true 

release, though it is reiterated that none of the data used in this evaluation have been independently 

verified. 

Chemical Forms of Tritium

One of the most important factors to consider in evaluating atmospheric releases of tritium for potential 

health risks is the chemical composition of the release. Specifically, one needs to know if the release was 

in the form of tritium gas or if it was partially or completely in the form of tritium oxide. Tritium is a 

radioactive isotope of hydrogen. Tritium gas refers to tritium in the form of diatomic HT or T2 gas, where 

T is used in place of H to differentiate between atoms of tritium and protium (normal hydrogen). Tritium 

oxide refers to molecules of water (normally H2O) in which a tritium atom has been substituted for one or 

both of the hydrogen atoms to form HTO or T2O. The difference between tritium gas and tritium oxide is 

enormous in terms of radiation dose to a human receiver. If inhaled, tritium gas is not incorporated into 

the body to any appreciable degree, and the only dose consequence is the direct exposure to lung tissue. 

Tritium oxide, in contrast, behaves as water and is readily incorporated into body tissues. In terms of 

radiation dose per unit intake, the dose from tritium oxide exceeds that from tritium gas by four orders of 

magnitude (ICRP 1996). Dose from tritium gas, therefore, is typically negligible. There is no external 

dose consequence from tritium in either form, but intakes of tritium oxide can result from absorption 

through exposed skin in addition to inhalation. 

Given its application in the weapons program and accelerator operations, tritium at Los Alamos has 

primarily been used in the form of tritium gas. However, there are some circumstances where an 

assumption of the oxide form is appropriate, at least for purposes of initial screening. In addition, as of 

the late 1970s, LANL had installed catalytic converters on its tritium stacks to convert the gaseous 

effluent to oxide. This allowed the tritium to be efficiently collected on molecular sieves and thus 

significantly reduce the overall release. However, anything not captured by the sieve system had taken 

the oxide form. This system for reducing tritium emissions was described in 1973 by R. R. Dube of 

LASL’s GMX-4 group and his colleagues (Dube et al. 1973). 
7-8 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 7

There are other chemical forms of tritium possible in addition to gas and oxide. With respect to tritium 

operations at LANL, tritium could historically be found in the form of metal (uranium) tritides or lithium 

tritide salts. Unlike gases, any atmospheric emissions of these materials would be in a particulate form 

and absorption and retention in the body would depend on the characteristic biokinetic behavior for the 

specific tritide compound. No information has been noted in the LAHDRA document collection 

regarding the atmospheric release of tritide compounds, and it is believed to be unlikely that tritides 

would have been a significant component of LANL’s atmospheric tritium releases. From a radiation dose 

perspective, tritides can represent more dose per unit activity than tritium oxide because they are retained 

in the body longer. In the case of tritide particulates, with the longer retention characteristics, the dose 

per unit intake exceeds that for tritium oxide by a factor of 14 (ICRP 1996). 

Screening LANL’s Atmospheric Tritium Releases for Potential Health Risks

The NCRP Report No. 123 (NCRP 1996) screening method for radionuclide releases to the environment 

was used to evaluate atmospheric tritium releases from LANL in terms of their potential risk to local 

residents. The source term used was the maximum release reported for each of the six TAs that 

represented the largest contributors to LANL’s atmospheric tritium releases. These maximum values, 

shown in Table 7-2, were converted to units of becquerels for input into the NCRP Report No. 123 

screening models. The converted values are shown in Table 7-3. 

Table 7-3. Maximum reported airborne tritium releases from LANL 

Technical Area Maximum Release (Bq) Year 

3 3.84×10+14 1968 

15 4.07×10+14 1970 

21 2.97×10+13 1984 

33 1.37×10+15 1977 

35 9.25×10+14 1970 

41 5.84×10+14 1968 

The values in Table 7-3 reflect total amounts of tritium released. To ensure a meaningful screening 

result, they were re-stated in terms of the corresponding tritium oxide activity for each total value. An 

upper bound for the fraction of a tritium gas source that has converted to an oxide form is 1% (Pan and 

Rigdon 1996, Mishima and Steele 2002). The small amount of oxide is formed by interactions between 

residual air in the storage vessel and beta radiation from the tritium. Following a release of tritium gas, 

additional oxidation occurs slowly, resulting from either additional radiolytic reactions with air (in the 

case of high activity concentrations) or from photochemical reactions with ultraviolet light. These 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 7 7-9

secondary oxidation mechanisms result in a conversion rates ranging from approximately 1% per hour, in 

the case of high activity concentrations, falling off to less than 1% per day as the gas diffuses following 

release (Mishima and Steele 2002). Tritium gas does not react strongly with water vapor. If there is an 

ignition, explosion, or similar event involving tritium gas, then an assumption of complete (100%) 

oxidation is appropriate. 

Based on what was known about the processes associated with the maximum atmospheric tritium releases 

in Table 7-3, conservative assumptions were applied to determine the chemical form of the tritium to be 

assumed for screening. These are documented in Table 7-4, with tritium oxide being designated HTO. 

Table 7-4. Activity and chemical forms of tritium used for screening 

Technical 

Area 

Maximum 

Release (Bq) Assumed Chemical Form and Basis Maximum Release as Oxide (Bq) 

3 3.84×10+14 1% HTO: principal sources were tritium 

gas. 

3.84×10+12

15 4.07×10+14 100% HTO: assume tritium was expended 

in detonation events. 4.07×10+14

21 2.97×10+13

100% HTO: assumed releases were the 

result of water reactions with tritiumbearing salts resulting in an oxide form. 2.97×10+13

33 1.37×10+15 1% HTO: HP-86 was a tritium gas facility. 1.37×10+13

35 9.25×10+14

100% HTO: assumed releases were the 

result of water reactions with tritiumbearing salts resulting in an oxide form. 9.25×10+14

41 5.84×10+14 1% HTO: operations were similar to those 

at TA-33. 5.84×10+12

Total 3.70×10+15 -- 1.39×10+15

For screening, the maximum release values in Table 7-4 were considered both on an individual and on an 

aggregate basis (the six values added). Summing the maximum values, which occurred in different 

calendar years, is believed to provide a source term that is at worst representative of any specific year and 

is likely bounding. It is reiterated that the maximum release data for TAs 3, 15, 35, and 41 are based on 

LANL’s examination of accountability records, and such assessments are typically conservative with 

respect to actual releases. On an aggregate basis, the source term in Table 7-4 represents 3.70×10+15 Bq 

(100,000 Ci) of tritium and 1.39×10+15 Bq (37,600 Ci) of tritium oxide. The effective oxide fraction for 

the aggregate source term is 38%. 

Screening was performed against a criterion of a 1 in 100,000 added risk of fatal or non-fatal cancer, 

assuming a risk factor of 6% per sievert (Sv) (ICRP 1990). This corresponds to a dose equivalent of 
7-10 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 7

1.67×10-4 Sv. The exposed population selected for each screening assessment was the residential 

population nearest each release point. The pathways considered for each residential location were 

inhalation of contaminated air and consumption of contaminated soil and vegetables. Consumption of 

locally raised meat or milk were not considered. 

The first step of the NCRP Report No. 123 screening process is to perform a Level I screening evaluation, 

which is the simplest and most conservative type of evaluation. The Level I screen does not account for 

distance from the source to the receiver or the associated atmospheric dispersion. If the Level I screening 

result exceeds the screening criterion, then one progresses to a Level II approach in which distance to the 

receiver and atmospheric dispersion are considered. Also, in the Level II screen, the screening criterion is 

reduced by an order of magnitude to account for uncertainties. If the Level II screening result exceeds the 

criterion, then a Level III screen is performed. In general, the Level III screen only differs from the Level 

II in how dose pathways are considered. The approach used here for screening LANL’s atmospheric 

tritium releases was hybridized in that the appropriate pathways were accounted for from the outset, 

rather than first screening for all pathways and then removing the non-applicable pathways afterward. 

A Level I screen was performed for the TA-3 release first, since it was the smallest contributor to the 

tritium oxide source term. If the Level I screening evaluation for the TA-3 release exceeded the screening 

criterion, there would be no need to continue with Level I screening for the other releases. As shown in 

Table 7-5, the Level I screening evaluation for the TA-3 source term exceeded the screening criterion by a 

substantial margin. Screening therefore proceeded to Level II/III. 

Table 7-5. Level I screening for the maximum HTO release from TA-3 

Basis

Total Release = 3.84E+12 Bq HTO OSR database Rev. 7, 1% HTO

Seconds per year = 3.2E+07 NCRP 123 I-A-2

Annualized Release Rate = 1.2E+05 Bq/sec (calculated)

Volumetric Flow Rate = 0.3 m3

/sec NCRP 123 I-A-3

Exhaust vent concentration = 4.0E+05 Bq/m3 (calculated)

Receiver concentration = 1.0E+05 Bq/m3 calculated via NCRP 123 I-A-5

Screening Factor = 7.20E-07 Sv per Bq/m3 NCRP 123 Table B.1 (inhalation + vegetables + soil)

Screening Value = 7.2E-02 Sv (calculated)

Screening Criterion = 1.67E-04 Sv 1E-05 excess risk at 6% per Sv

Screening criterion exceeded? YES
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 7 7-11

To proceed to Level II screening, the distance from each release point (Technical Area) to the nearest 

residential area was estimated. Table 7-6 shows the location of the nearest residential area and the 

approximate distance in meters from each TA. 

Table 7-6. Approximate distances from tritium release points to the nearest residents 

Technical Area Nearest Residents 

Approximate 

Distance (m) 

3 Western Area 1,740 

15 Royal Crest Trailer Park 3,050 

21 Town Site Apartments 1,460 

33 White Rock 3,750 

35 Royal Crest Trailer Park 1,740 

41 Town Site Apartments 490 

In the Level II screening process, the estimated distances from the release points to the nearest residential 

locations are used to determine a plume diffusion factor. These factors are determined from plots 

provided in NCRP Report No. 123. To simplify the process, the bounding value of the diffusion factor 

was selected for each source-receiver distance. This eliminated the need to account for effective release 

heights and the possibility of building wake effects. It also added a further degree of conservatism. 

Tables 7-7 through 7-12 below show the Level IIb

 screening calculations for TAs 3, 15, 21, 33, 35, and 

41, respectively. In each of the six Level II screening calculations, the screening criterion has been 

reduced by an order of magnitude (factor of ten) for an additional degree of conservatism per NCRP 

Report No. 123. Thus, the judgments as to whether the screening criterion has been exceeded are made 

against the adjusted, rather than the actual, screening criterion. 

The screening evaluations show that only in the case of TA-35, for which the maximum release was 

treated as 100% HTO, was the adjusted screening criterion exceeded. In no case was the actual 

(unadjusted) screening criterion exceeded. If all of the screening results are summed, the result 

(8.17×10-5 Sv) is still less than half of the screening criterion of 1.67×10-4 Sv. Note that, in addition to the 

fact the maximum release values are being treated as if they all occurred in the same time span, summing 

the individual screening values represents the physical impossibility of a hypothetical population of 

residents simultaneously living at a location nearest each of the individual release points. The screening 

dose for the aggregate releases would be much lower for any of the individual residential areas. 

 

b

 In reality the Level II screening assessments may be thought of as Level III since only the applicable pathways are 

being considered. 
7-12 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 7

Table 7-7. Level II screening for the maximum tritium release from TA-3 

Total Release = 3.84E+12 Bq HTO OSR database Rev. 7, 1% HTO

Seconds per year = 3.2E+07 sec NCRP 123 I-A-2

Annualized Release Rate = 1.20E+05 Bq/sec (calculated)

Wind Speed = 2 m/sec NCRP 123 II-bi-7

Distance to receiver = 1740 m estimated from LAHDRA project map

Dispersion factor = 2.5E-05 m-2 NCRP 123 Fig. 1.4 (limiting value)

Receiver concentration = 3.75E-01 Bq/m3

Screening Factor = 7.20E-07 Sv per Bq/m3 NCRP 123 Table B.1 (inhalation + vegetables + soil)

Screening Value = 2.70E-07 Sv

Adjusted Screening Criterion = 1.67E-05 Sv 1E-05 excess risk at 6% per Sv, divided by 10 to

account for uncertainties per NCRP 123 II-F-5

Screening criterion exceeded? NO

Table 7-8. Level II screening for the maximum tritium release from TA-15 

Total Release = 4.07E+14 Bq OSR database Rev. 7, 100% HTO

Seconds per year = 3.2E+07 sec NCRP 123 I-A-2

Annualized Release Rate = 1.27E+07 Bq/sec (calculated)

Wind Speed = 2 m/sec NCRP 123 II-bi-7

Distance to receiver = 3050 m estimated from LAHDRA project map

Dispersion factor = 9E-06 m-2 NCRP 123 Fig. 1.4 (limiting value)

Receiver concentration = 1.43E+01 Bq/m3

Screening Factor = 7.20E-07 Sv per Bq/m3 NCRP 123 Table B.1 (inhalation + vegetables + soil)

Screening Value = 1.03E-05 Sv

Adjusted Screening Criterion = 1.67E-05 Sv 1E-05 excess risk at 6% per Sv, divided by 10 to

account for uncertainties per NCRP 123 II-F-5

Screening criterion exceeded? NO

Table 7-9. Level II screening for the maximum tritium release from TA-21 

Total Release = 2.97E+13 Bq HTO OSR database Rev. 7, 100% HTO

Seconds per year = 3.2E+07 sec NCRP 123 I-A-2

Annualized Release Rate = 9.28E+05 Bq/sec (calculated)

Wind Speed = 2 m/sec NCRP 123 II-bi-7

Distance to receiver = 1460 m estimated from LAHDRA project map

Dispersion factor = 3E-05 m-2 NCRP 123 Fig. 1.4 (limiting value)

Receiver concentration = 3.48E+00 Bq/m3

Screening Factor = 7.20E-07 Sv per Bq/m3 NCRP 123 Table B.1 (inhalation + vegetables + soil)

Screening Value = 2.51E-06 Sv

Adjusted Screening Criterion = 1.67E-05 Sv 1E-05 excess risk at 6% per Sv, divided by 10 to

account for uncertainties per NCRP 123 II-F-5

Screening criterion exceeded? NO
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 7 7-13

Table 7-10. Level II screening for the maximum tritium release from TA-33 

Total Release = 1.37E+13 Bq HTO OSR database Rev. 7, 1% HTO

Seconds per year = 3.2E+07 sec NCRP 123 I-A-2

Annualized Release Rate = 4.28E+05 Bq/sec (calculated)

Wind Speed = 2 m/sec NCRP 123 II-bi-7

Distance to receiver = 3750 m estimated from LAHDRA project map

Dispersion factor = 7E-06 m-2 NCRP 123 Fig. 1.4 (limiting value)

Receiver concentration = 3.75E-01 Bq/m3

Screening Factor = 7.20E-07 Sv per Bq/m3 NCRP 123 Table B.1 (inhalation + vegetables + soil)

Screening Value = 2.70E-07 Sv

Adjusted Screening Criterion = 1.67E-05 Sv 1E-05 excess risk at 6% per Sv, divided by 10 to

account for uncertainties per NCRP 123 II-F-5

Screening criterion exceeded? NO

Table 7-11. Level II screening for the maximum tritium release from TA-35 

Total Release = 9.25E+14 Bq HTO OSR database Rev. 7, 100% HTO

Seconds per year = 3.2E+07 sec NCRP 123 I-A-2

Annualized Release Rate = 2.89E+07 Bq/sec (calculated)

Wind Speed = 2 m/sec NCRP 123 II-bi-7

Distance to receiver = 1740 m estimated from LAHDRA project map

Dispersion factor = 2.5E-05 m-2 NCRP 123 Fig. 1.4 (limiting value)

Receiver concentration = 9.03E+01 Bq/m3

Screening Factor = 7.20E-07 Sv per Bq/m3 NCRP 123 Table B.1 (inhalation + vegetables + soil)

Screening Value = 6.50E-05 Sv

Adjusted Screening Criterion = 1.67E-05 Sv 1E-05 excess risk at 6% per Sv, divided by 10 to

account for uncertainties per NCRP 123 II-F-5

Screening criterion exceeded? YES

Table 7-12. Level II screening for the maximum tritium release from TA-41 

Total Release = 5.84E+12 Bq HTO OSR database Rev. 7, 1% HTO

Seconds per year = 3.2E+07 sec NCRP 123 I-A-2

Annualized Release Rate = 1.83E+05 Bq/sec (calculated)

Wind Speed = 2 m/sec NCRP 123 II-bi-7

Distance to receiver = 490 m estimated from LAHDRA project map

Dispersion factor = 2E-04 m-2 NCRP 123 Fig. 1.5 (limiting value)

Receiver concentration = 4.56E+00 Bq/m3

Screening Factor = 7.20E-07 Sv per Bq/m3 NCRP 123 Table B.1 (inhalation + vegetables + soil)

Screening Value = 3.29E-06 Sv

Adjusted Screening Criterion = 1.67E-05 Sv 1E-05 excess risk at 6% per Sv, divided by 10 to

account for uncertainties per NCRP 123 II-F-5

Screening criterion exceeded? NO
7-14 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 7

The NCRP Report No. 123 screening evaluation suggests airborne tritium releases from LANL were 

unlikely to have been a source of adverse health risks to local residents around Los Alamos. The 

possibility cannot be ruled out entirely, however, in light of the screening result for TA-35. Further, there 

are caveats to consider, including the possibility that larger releases could have occurred prior to 1967 

(when atmospheric tritium releases were first estimated by LANL) or that some of the releases consisted 

of a greater fraction as tritium oxide (HTO) than has been considered here. But given the degree of 

conservatism used in the screening method, it appears the impacts of such effects would have to be 

substantial before atmospheric tritium releases would have posed a significant health risk. 

As a check on the intended conservatism in the screening approach used for atmospheric tritium releases, 

local environmental monitoring data for tritium oxide (HTO) were compiled for the period July 1970 

through December 1979. This period was expected to encompass the largest airborne tritium releases 

from LANL for the era when environmental monitoring data are available. Table 7-13 shows the 

maximum annual average concentrations for the on-site and off-site environmental tritium monitoring 

stations on and around the LANL site for July 1970 to December 1979. The on-site data were included in 

this evaluation to both be conservative and to allow for the fact that the public historically has had access 

to many “on-site” locations at LANL. 

Table 7-13. Maximum tritium oxide concentrations from the LANL environmental air monitoring 

stations 1970 – 1979 

Maximum On-Site Average Maximum Off-Site Average 

Year 

Concentration 

(μCi mL-1) Location Concentration 

(μCi mL-1) Location 

LAHDRA 

Reference 

(Repos. No) 

1970* 1.80×10-11 unknown 3.50×10-12 “Community” 2178 

1971 2.40 ×10-10 Array 156-9.4 1.20×10-10 Array 42-3.1 2155 

1972 1.80×10-10 Array 156-9.4 4.40×10-11 Array 164-8.5 887 

1973 1.51×10-10 TA-21 2.70×10-11 Fuller Lodge 2161 

1974 1.41×10-10 TA-33 3.60×10-11 Fuller Lodge 2157 

1975 1.74×10-10 TA-52 9.30×10-11 Fuller Lodge 2158 

1976 3.30×10-10 TA-54 5.10×10-11 Los Alamos airport 2159 

1977 1.87×10-10 TA-54 5.10×10-11 Los Alamos airport 2069 

1978 5.70×10-11 TA-54 2.60×10-11 Los Alamos airport 953 

1979 4.00×10-11 TA-33 6.70×10-12 Royal Crest Trailer Park 2190 

*July – December 1970 

The elevated HTO concentrations at TA-54 are the result of evaporative losses from soil containing 

buried, tritium-contaminated wastes. Tritium oxidizes slowly in the environment at a rate of less than 1% 

per day (Mishima and Steele 2002). The fact the TA-54 sampling station is the location of the maximum 

measured on-site HTO concentrations for some years shows the importance of TA-54 as a source of 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 7 7-15

airborne releases of tritium oxide relative to other sources. The tritium oxide concentration for the TA-54 

environmental monitoring station for 1976 was the largest of all of the on-site annual averages for July 

1970 through December 1979. The largest off-site annual average for this period was at the location 

designated Array 42-3.1 for 1971. It is difficult to discern the precise location of this monitoring station 

in the reference, but it appears that it might be at or near the Fuller Lodge location. 

From Table 7-13, the maximum annual average airborne tritium oxide concentrations reported by the 

LANL environmental air monitoring network for July 1970 through December 1979 were 3.3×10-10 μCi 

mL-1 (12.2 Bq m-3) and 1.2×10-10 μCi mL-1 (4.4 Bq m-3) for on-site and off-site locations, respectively. 

One can gauge what these concentrations imply in terms of dose to human receivers by applying 

screening factors for tritium oxide from NCRP Report No. 123. For the on-site locations, the appropriate 

factor to use is that for inhalation alone. The combined factors for inhalation and consumption of 

contaminated vegetables and soil are appropriate for the off-site locations. These screening factors are 

1.4×10-7 Sv per Bq m-3 for inhalation and 7.2×10-7 Sv per Bq m-3 for the combination of inhalation and 

consumption of contaminated vegetables and soil. 

Multiplying the inhalation screening factor by the maximum on-site concentration value (in consistent 

units) gives a screening dose equivalent value of 1.7×10-6 Sv, or 0.17 mrem. Note this calculation 

requires the extremely conservative assumption of 100% occupancy at the on-site location. The same 

calculation for maximum average off-site concentration, using the combined factor for inhalation and 

vegetables, gives a screening dose equivalent of 3.2×10-6 Sv, or 0.3 mrem. Including the vegetation 

pathway results in a higher screening dose than the on-site location despite the lower average air 

concentration. Nonetheless, both of these values are well below the screening criterion of 1.67×10-4 Sv 

(16.7 mrem). 

As with the screening assessment performed using atmospheric release data for tritium, measured values 

of tritium oxide concentrations in the local environment around Los Alamos also suggests that airborne 

releases of tritium from Los Alamos are unlikely to have resulted in any adverse health risks to the local 

residents. However, as with the effluent data, the environmental monitoring data have been used as 

reported without any adjustments or verification, and they do not consider the period prior to 1970. 
7-16 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 7

References 

Allison SK. April 10, 1944 letter from the Metallurgical Laboratory to X-10 Site concerning tritium 

production at Oak Ridge. 1944. Repos. No. 3315. 

Barnes JW. TA-41 Tritium Release Analysis; memorandum to LJ Johnson dated 15 September 1976 

(WX-4-445). Los Alamos Scientific Laboratory. 1976. Repos. No. 3389. 

Buckland CW. Spread of Plutonium in TA-41 W-7 Area; memorandum to distribution dated 23 January 

1957. Los Alamos Scientific Laboratory. 1957. Repos. No. 4677. 

Coffin DO. Environmental Impact of HP-86 Operations; memorandum to JE Dougherty dated 2 June 

1971 (W-3-71-4619). Los Alamos Scientific Laboratory. 1971. Repos. No. 6860. 

Deinken HP. Report on Outer Perimeter Safety Survey for TA-33; memorandum to Roy Reider dated 15 

November 1962 (W-3-1896). Los Alamos Scientific Laboratory. 1962. Repos. No. 1829. 

DNFSB. Review of Tritium Operations and Emergency Hazard Assessment at Los Alamos National 

Laboratory. Defense Nuclear Facilities Safety Board; 2001. 

Dube CM, Coffin DO, Stoll RD. An Apparatus for the Reduction of Tritium Emissions into the 

Atmosphere. Los Alamos, NM: Los Alamos Scientific Laboratory; LA-5303-MS; 1973. 

Erickson DJ. Letter to J.L. Bellows dated 4 February 1993 (ADNWT 93-050). Los Alamos National 

Laboratory. 1993. Repos. No. 6158. 

Garcia KLM, McGehee ED, Ronquillo J, Isaacson J. Upgrades to TA-33-87, -88, and -89. Los Alamos, 

NM: Los Alamos National Laboratory; LA-UR-04-6061; 2004. Repos. No. 7846. 

Harper JR, Garde R. The Decommissioning of a Tritium-Contaminated Laboratory. Los Alamos, NM: 

Los Alamos National Laboratory; LA-9056-MS; 1981. Repos. No. 6372. 

Holmes V. An Accidental Release of Radioactive Tritium Gas to the Atmosphere at TA-33 on February 

16, 1965; memorandum to Dean Meyer dated 4 March 1965 (H-1-M-252). Los Alamos Scientific 

Laboratory. 1965. Repos. No. 4173. 

ICRP. 1990 Recommendations of the International Commission on Radiological Protection. New York; 

ICRP Publication 60; 1990. 

ICRP. Age-Dependent Doses to The Members of the Public from Intake of Radionuclides Part 5, 

Compilation Of Ingestion And Inhalation Coefficients. Vienna, Austria: International 

Commission on Radiological Protection; ICRP Publication No. 72; 1996. 

Jalbert RA. Tritium Stack Releases from TSTA; memorandum to F. Guevara dated 19 February 1985 

(MST-3/TSTA-20-85) Los Alamos National Laboratory. 1985. Repos. No. 397. 

Johnson LJ. Calibration Check of DP513 Tritium Monitor; memorandum to J.W. Anderson dated 4 June 

1971. Los Alamos Scientific Laboratory. 1971. Repos. No. 6106. 

LANL. TA-41 Unit Information. Los Alamos National Laboratory. 1988. Repos. No. 6498. 

LANL. Environmental Assessment for the Weapons Engineering Tritium Facility Building 205, TA-16. 

Los Alamos, NM: Los Alamos National Laboratory.; 1990. Repos. No. 3602. 

LANL. TA-41 Facility Description. Los Alamos National Laboratory. 1991. Repos. No. 2660. 

LASL. Monthly Progress Report of the Chemistry and Metallurgy Division Los Alamos, NM: Los 

Alamos Scientific Laboratory; LAMS-357 1946. Repos. No. 1950. 

LASL. Tritium Release Data 1967 – 1972. Los Alamos Scientific Laboratory. . 1973. Repos. No. 1810. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 7 7-17

Loomis E, McGehee ED, Garcia KM, Towery K, Ronquillo J. The Decommissioning of TA-3-16, the Ion 

Beam Facility (IBF). Los Alamos. NM: Los Alamos National Laboratory; 2005. Repos No. 7840. 

Mishima J, Steele CM. Oxidation of Tritium Gas Under Accident and Transport Conditions. Los Alamos, 

NM: Los Alamos National Laboratory; LA-UR-02-3803; 2002. Repos. No. 4800. 

Morgenstern M, Hueske K. Air Modeling as an Alternative to Sampling for Low-Level Radioactive 

Airborne Releases. 50th Purdue University Industrial Waste Conference; 1995. 

Nasise JE. Performance and Improvements of the Tritium Handling Facility at the Los Alamos Scientific 

Laboratory (LA-UR-80-1265). American Nuclear Society Topical Meeting on Tritium 

Technology in Fission, Fusion, and Isotopic Applications; 1980. 

NCRP. Screening Models for Release of Radionuclides to Atmosphere, Surface Water, and Ground. 

Bethesda, MD: National Council on Radiation Protection and Measurements; NCRP Report No. 

123; 1996. 

Pan PY, Rigdon LD. Tritium Oxidation in Atmospheric Transport. Los Alamos, NM: Los Alamos 

National Laboratory; LA-UR-96-2953; 1996. 

Storm E. Appraisal of TA-35 (Ten Site); memorandum to Dean Meyer and JNP Lawrence dated 18 May 

1972. Los Alamos Scientific Laboratory. 1972. Repos. No. 1417. 

Tuggle DG. Weapons Subsystems Laboratory [construction proposal from LANL Archives Collection A2007-002-668-1]. Los Alamos National Laboratory. 1983. 

Webber JB. Tritium Results on Water Samples, Room 326, DP West; memorandum to Dean Meyer dated 

15 May 1952. Los Alamos Scientific Laboratory. 1952. Repos. No. 4881. 
7-18 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 7

This page intentionally left blank 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 8 8-1

Chapter 8: Hot Cell Facilities and Operations at LANL 

Beginning with early operations, LANL processed highly radioactive material, such as fission products, to 

meet the production and research needs of the Lab and the federal government. Much of the work on 

radioactive materials at the laboratory was carried out in specialized, shielded enclosures called “hot 

cells” that provided protection for the workers by reducing their radiation exposures. Remote 

manipulators, also called mechanical hands, were used to handle the isolated radioactive materials inside 

the hot cells. The hot cells also provided some level of control in helping to reduce releases of radioactive 

material to the environment. 

In 1944, LANL began receiving its first shipments of multiple curies of 140Ba for use in extracting 140La, a 

radionuclide used as a tracer for hydrodynamic explosive tests conducted during the Radioactive 

Lanthanum (“RaLa”) program. Due to the high gamma energy and radiation fields associated with these 

materials, LANL designed and built its first hot cell facility in order to safely extract the 140La for further 

processing. Over the course of many years, LANL built several additional hot cell facilities to meet the 

growing needs of the federal government and other customers and by the early 1980s had approximately 

36 hot cells in operation. 

In addition to 140Ba/140La operations, hot cells were used for (Wilson et al. 1979): 

 handling and manufacturing of nuclear reactor fuels and fuel assemblies, 

 chemical separation and analysis of irradiated reactor fuels, 

 radionuclide analyses, such as with fission products, supporting nuclear weapon tests, 

 accelerator-based production of radionuclides for medical and research applications, 

 fabrication and testing of fuels associated with the Rover nuclear propulsion and the Ultra HighTemperature Reactor Experiment (UHTREX) projects, 

 storage and processing of materials with high tritium concentrations, and 

 chemical separation, isotopic analysis, treatment and volume reduction, and storage of high-level 

radioactive waste in support of a variety of laboratory and other governmental programs. 

LANL’s hot cell facilities were used in the handling of large quantities of fission products, and to a lesser 

extent plutonium, uranium, and other heavy elements. Because of the higher radioactivity handled in 

these facilities, the project team collected information on hot cell operations to support potential 

prioritization of associated releases in the future. This chapter is intended to provide an overview of 

LANL’s hot cell operations and highlight those that may warrant further investigation. In the preliminary 
8-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 8

prioritization analyses that have been performed, fission products were found to be less important than 

several other classes of other radionuclides. However, the analyses performed to date have been largely 

dependent on release estimates put forward by LANL, and waste streams associated with hot cell 

operations appear to have not always been among the top priorities within programs for monitoring and 

estimation of releases to the environment. Several comments have been made during past LAHDRA 

public meetings that indicate a belief among some members of the public that releases from hot cell 

operations have not been adequately disclosed, characterized, or quantified. Some believe that releases 

of radioiodine and other fission products could have been significantly larger than has been disclosed, and 

that an independent evaluation of associated historical activities is warranted. A summary of LANL hot 

cell operations is presented in Table 8-1 at the end of this chapter. 

Over 8,000 documents or sets of documents that are included in the LAHDRA project information 

database were searched by team members for information pertaining to hot cell and associated operations. 

A summary of related information that has been extracted is presented below. 

The RaLa Program 

Chemical extractions of lanthanum during the initial years of the program for testing the implosion 

process (1944-1950) were performed using 1.5- to 2- m high, shielded shipping casks and were carried 

out in a wooden building located in Bayo Canyon, TA-10 (Wilson 1979). Operators located 

approximately 27 m from the casks using electric cranks, cabling, and remote tongs, along with telescopes 

and mirrors for viewing, lowered reagents into casks to complete the chemical separation of barium and 

lanthanum. One hundred and fifty sources of 140La ranging in source strength from 40 to over 3,000 Ci 

were prepared and used in explosives tests from September 1944 to July 1950. The crude remote 

handling facility that was used at TA-10 was modest by today’s standards for hot cell design and 

performance, but it served its purpose until it was phased out of operations in the early 1950s. 

In 1947, LANL began construction of a new hot cell facility at Ten Site (TA-35) to process the barium 

and lanthanum. Completed in 1951 at a cost of nearly $3 million, the facility consisted of two 3-m by 

6-m by 2.5-m high hot cells. A crane and trolley system was used to move radioactive materials in and 

out of the cells. The trolley housed a rotatable spindle with pins on one end to mate with bayonet slots of 

various tools, vessels, and equipment components inside the hot cells for handling and processing of 

materials. An operator’s view inside a hot cell was accomplished through shielded glass windows (such 

as leaded glass) and a series of mirrors and retractable periscopes. A large auxiliary building was used to 

handle and purify air and house liquid filtration and treatment equipment. Believed to have been the first 

modern hot cell design to handle high-level radioactive materials, the TA-35 facility contained innovative 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 8 8-3

features such as exterior, contamination–free lighting, cell wash-down sprays, collimated ports for 

experiments, and hydraulic rams for opening and handling shipping casks. LANL later added concrete 

caves with a zinc bromide window above the hot cells to provide flexibility in packaging lanthanum 

sources. In 1963, these operations terminated after processing about 2 million curies from the Chemical 

Processing Plant at the Idaho Falls (Wilson 1979). 

Hot Cells Associated with LANL Reactors

A series of research and production reactors were operated at Los Alamos dating back to 1943. These 

reactors were largely used in fuel and neutron experimentation and for research and production of fission 

products and activation products (Wilson, 1979). The first of these reactors were the Water Boiler series 

reactors– LOPO, HYPO, and SUPO– as described in Chapter 5. The Clementine reactor, located at 

Omega Site (TA-2) at the bottom of Los Alamos Canyon, was commissioned in November 1946 and was 

the first reactor to use 239Pu as its fuel. Hot cells were used to test the fuel and reactor components 

following neutron irradiation experiments. Corrosion of steel cladding began to release considerable 

alpha contamination into the mercury coolant which led to the shutdown and decommissioning of the 

reactor in 1952. According to LANL employees at the time, no detectable radioactivity was released to 

the environment during these fuel rod failures (Wilson 1979). 

The Omega West Reactor was built at the same location where Clementine existed and was operated from 

1956 to 1994 to support a variety of research programs. Irradiated fuel from Omega West was transferred 

to hot cells for chemical processing and testing. In some cases, isotopes were extracted to support or 

research programs. 

LANL used a series of compact reactors that were assembled and tested at Ten Site in the 1950s and 

1960s to test new technologies used in reactor and fuel assembly designs. These were called the Los 

Alamos Power Reactor Experiment (LAPRE) and used plutonium dissolved in phosphoric acid. LAPRE 

I was a forced-convection, high pressure, water-cooled reactor that was later drained and 

decommissioned. LAPRE II used natural convection. This operated for short time and then shut down. 

Irradiated fuel and reactors components and equipment were tested inside the TA-35 hot cells. Typical 

processes involved chemical separation, analytical measurements of radionuclides, and preparation for 

waste disposal. A third reactor known as the Los Alamos Molten Plutonium Reactor Experiment 

(LAMPRE) was operated within the Ten Site hot cell adjacent to the one used to extract 140La in the RaLa 

program. The fuels from these reactors were eventually transferred for storage to the CMR Wing 9 hot 

cell facility at TA-3 for further processing and waste disposal (Wilson 1979). 
8-4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 8

General Purpose Hot Cells

Since 1951, LANL has operated 36 general purpose hot cells in four separate on-site facilities. These are 

described as general purpose cells because their designs permitted considerable flexibility for storage, 

processing, and handling of radioactive materials. This section presents a description for each of these 

facilities. Hot cell operations are active, or have been active, at the following LANL facilities: 

• TA-3, CMR Building, Wing 9 Operations, 

• TA-21, DP West Site, Building 4, Room 401, 

• TA-48, Radiochemistry Laboratory, 

• TA-50, Contaminated Waste Treatment Facility, 

• TA-52, UHTREX Facility, and 

• TA-53, LAMPF/LANSCE Facility. 

TA-3; CMR Building Wing 9 Hot Cells 

The CMR Wing 9 hot cell facility began operations in December 1961. The facility was used to support 

the civilian power reactor program from 1961 to 1967, the Rover Nuclear Propulsion Project from 1961 

to 1973, and the Liquid Metal Fast Breeder Reactor (LMFBR) from 1967 to the early 1980s. The facility 

has also provided assistance to numerous LANL programs by performing various experiments involving 

high levels of gamma radiation associated with irradiated fuel and fission product samples. The facility 

still supports a variety of LANL programs, including transuranic (TRU) waste treatment and packaging 

for disposal at the DOE WIPP site 

in Carlsbad, New Mexico (LANL 

1999). 

The Wing 9 hot cell facility consists 

of sixteen 2-m by 2-m by 3.6-m 

high hot cells arranged in two 

groups of eight cells separated by 

shielded corridors. Fig. 8-1 

represents a cutaway drawing of the 

Wing 9 hot cell facility. The ferrophosphorus walls and leaded-glass 

windows shield up to 30,000 Ci of 

mixed fission products or 50,000 Ci 

Fig. 8-1. Wing 9 hot cell facility at TA-3’s CMR Building 

(LANL 1999) 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 8 8-5

of 1 MeV gamma radioactivity (Wilson 1979; Valentine et 

al. 1968). A storage area consists of 364 shielded holes that 

are cooled and maintained at negative pressure. Areas 

within the facility are designed for decontamination 

activities, mock-up runs, machine shop, manipulator repair, 

cold laboratory, dark room, and staff offices. Fig. 8-2 is a 

photograph that shows the exterior work stations and the 

shielded glass viewing windows, manipulator arms, and 

control panels for a group of four Wing 9 hot cells located in 

the CMR Building. 

Airborne effluents from the CMR Wing 9 hot cells are 

filtered and monitored for particulates and radioiodine with 

fiber and charcoal filters, respectively. Air from three 

monitored compartments is discharged at a rate of 176,840 

ft3

 min-1 through a 56 ft tall stack. Air samples are collected on a 24-h basis and analyzed for 235U, 238U, 

239Pu, 241Am, fission products, and 131I. Sampling results and details of the sampling program are reported 

in LANL reports and were reviewed by the LAHDRA team. Early effluent monitoring results are 

published in monthly Health Division reports and special reports that present monitoring results for nonroutine releases and discussion of general issues related to stack monitoring and airborne emissions and 

their impact in the environment. Monitoring results are also published in LANL’s Annual Environmental 

Surveillance reports for the years 1970 to the present. 

Stack sampling and filtering of effluents for the Wing 9 hot cells began at the start of operations and 

underwent of number of changes and improvements over the years. In a 1970 memorandum, LANL 

reports that the CMR stack sampling was not isokinetic, results were therefore not representative of 

quantities actually discharged, and improvements were needed in order to generate reliable release 

estimates (Meyer 1970, Enders 1970). Upgrades and new procedures were implemented to improve the 

exhaust filtration and monitoring program as highlighted in numerous Health Division reports and 

memorandums (Lawrence 1970). Efforts to reduce emissions were also being emphasized during this 

period because of the forthcoming reductions in AEC release limits for radioactive isotopes. Other 

reports also depict LANL’s efforts to improve monitoring and control of airborne releases from other 

CMR wings and exhaust stacks (LASL 1975). 

Fig. 8-2. CMR Building Wing 9 hot cells
8-6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 8

Solid radioactive waste from these and other hot cell operations were disposed of at the former TA-21 and 

TA-54 burials grounds. Waste was often treated or consolidated and packaged into a variety of containers 

(such as 55-gallon metals drums) and transported to the burial grounds for shallow-land burial. Land 

burial at LANL began during the 1940s and continued up through recent years. 

Small volumes of liquid waste from hot cell operations that contain plutonium, americium, uranium, and 

fission products along with reacted sodium and sodium potassium solutions were placed in 3.8 L or 

smaller containers and then packed in 7.8 L cans with dry vermiculite for shaft burial at the burial 

grounds. Other waste containing higher levels of radioactivity were transported to TA-50 for treatment 

(LASL 1975). 

 

T-21; DP West Site Room 401 Hot Cells 

Construction of four hot cells began in 1958 in Building 4 at TA-21. These cells were designed to handle 

kilogram quantities of irradiated plutonium that possessed kilocuries of gamma activity and to support 

evaluation of plutonium fuel reprocessing schemes up through 1967. The facility then remained idle for 

the next three years until the cells were used to perform in-depth, post-irradiation examinations of reactor 

fuel elements. The 2-m by 2-m by 6.5-m high cells were interconnected by a 3-m by 10-m, shielded 

corridor with rolling steel doors and 22 storage wells located on the floor that are 1.5 m deep. The cells 

were equipped with manipulators for remote processing, and radioactive material was moved in and out 

via a transfer can system. This facility was partially decommissioned in the 1980s and has been under a 

maintenance and preservation program since. The future plans for many of the buildings at TA-21 are 

currently under review by the laboratory. 

The Room 401 hot cells were designed with a negative pressure water circulating system. If there was a 

breach in the system, air would leak into the system rather than letting water leak into the cells. This 

minimized the chances of a nuclear criticality accident and reduced the potential for a large of amount of 

contaminated water that would have otherwise flooded the cells. This design did, however, create 

airborne emission concerns. 

As reported in two 1961 Health Division memos regarding the DP West Room 401 Hot Cells, LANL 

recognized that process air concentrations and releases of 131I had become a concern and needed to be 

addressed through the use of improved source control and exhaust vent and stack filtration (Dummer 

1961). Fig. 8-3 provides an example report of air concentrations above the maximum permissible 

concentrations (MPCs) that highlighted those concerns. The elevated air concentrations were due to 

dissolution and analysis processing of an 82-g plutonium foil that had been irradiated in the Omega West 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 8 8-7

Reactor. The reports suggest that this was not a one time occurrence and that greater attention was 

required to reduce these airborne emissions in the future. 

LANL also stated in memos that, before another sample was run, some effort to prevent iodine dispersal 

should be made– that is, charcoal filters should be installed at the drybox exhaust ports (Dummer 1961). 

Fig. 8-4 depicts the layout of the DP West, Room 401 hot cell facility and represents the sequence of air 

samplers and exhaust air filters in relation to the exhaust stack. 

TA-48 Radiochemistry Hot Cell Facility 

The TA-48 Radiochemistry Hot Cell Facility became operational in 1959 and was designed for 

evaluations and experiments with irradiated fuel and fission products. The facility was also used for other 

programs such as actinide chemistry experiments, isotope separation and production for medical and 

research uses, in-depth fuel analyses, and fission product and fuel testing of samples collected following 

nuclear weapon detonation tests (Wilson et al 1979). The first cell utilized three work stations and was 

design to store and handle hundreds of curies of radioactivity. TA-48 hot cells are still in use today for 

processing, testing, and storage of radioactive materials (Hyder 1992). 

Fig. 8-3. DP West hot cell 131I air sample results (from Dummer 1961) 
8-8 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 8

In 1963, twelve more cells were built in an adjacent building at TA-48 for dissolution and evaluation of 

graphite fuel used in the Rover program. The cells are 1.5-m by 1.7-m by 2.7-m high and arranged in two 

rows of six separated by a shielded corridor. The Rover project ended in 1973, and some of the cells were 

later modified to handle uranium, plutonium, transuranics, and fission products. Releases of 131I and other 

fission products gained the attention of LANL staff. While it is unclear how rapid LANL’s response to 

the issue was, it is clear that Health Division staff published their concerns about the issue during early 

operations. 

Fig. 8-5 presents an example of a LANL document that highlights radioiodine releases and concerns 

about off-site emissions from the TA-48 hot cells. Much of their concerns focused on residents living in a 

nearby trailer court (Royal Crest Trailer Park) located approximately 1000 m from the TA-48 exhaust 

stack. Hot cells at TA-48 were used to experiment with a variety of less commonly used radionuclides 

such 227Ac, 76Br, 77Br, 82Br, and 237U (Dummer 1979a, b). 

Fig. 8-4. DP West hot cell layout showing monitoring and filters (Dummer 1961) 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 8 8-9

Fig. 8-5. 1964 H-Division memo addressing airborne iodine releases at TA-48 (Buckland 1964) 
8-10 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 8

LANL took steps to reduce these iodine releases by adding additional charcoal filters to exhaust air 

systems. They also improved their stack sampling and monitoring systems and practices over time so that 

results more accurately quantified releases to the environment (Maestas 1967). 

Process air from TA-48 hot cells and surrounding areas was consolidated and exhausted through two 

main exhaust plenums, designated as FE-38 and FE-48, and then vented to the outdoor atmosphere 

through an elevated stack (Maestas 1969; Maestas 1970; Maestas 1971). The Maestas references cited 

here are sample reports selected from a series of weekly Health Division reports located in the LAHDRA 

database. 

TA-50 Contaminated Waste Treatment Plant Hot Cell Facility 

As part of the Chemical Waste Treatment Plant at TA-50, a hot cell facility became operational in 1963 to 

handle high levels of beta-gamma emitting radioactive material. The hot cell facility was primarily used 

to neutralize liquid waste and package the treated and consolidated waste for long-term storage and 

disposal. The facility consisted of a cask unloading dock, transfer and storage area, and one 2-m by 3-m 

by 4-m high hot cell. 

TA-52 UHTREX Hot Cell 

This hot cell was built in 1965 to provide a properly-shielded place to exchange fuel assemblies and 

perform testing of irradiated fuel. The facility was shut down in 1968 along with the UHTREX project. 

Fast Reactor Core Test Facility 

Construction of this facility began in 1963 and was completed in 1966. The project and associated use of 

the hot cell facility for handling plutonium fuel was terminated before any of the systems or structures 

were tested or used. 

TA-53 LAMPF/LANSCE 

The accelerator complex at TA-53 contains two hot cells with four work stations. These hot cells have 

been in operation since 1976. The cells are used for radiochemical experiments and medical and research 

isotope production and separation. Isotope separation was also performed inside the hot cells at Wing 9, 

CMR Building at TA-3. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 8 8-11

Hot Cell Decontamination and Waste Disposal

The largest amount of radioactive waste generated by hot cell operations came from the hot cells located 

at TA-3 (Wing 9), TA-21 (Room 401), TA-35 (Ten Site Laboratory), TA-48 (Radiochemistry 

Laboratory), and TA-50 (Waste Treatment Plant). Methods used to decontaminate, treat, and dispose of 

liquid and solid waste from LANL’s hot cell operations varied according to the levels of radioactivity and 

types of radioactive materials processed in a given project. Much of the removal, treatment, 

consolidation, and disposal of highly radioactive residues and wastes generated inside hot cells involved 

the use of remotely-operated, jet spray washing and dry and wet vacuum systems (Dummer, 1965; LANL 

1974). Treatment of highly radioactive liquid waste was performed at the Contaminated Waste Hot Cell 

facility located at TA-50 

Removal and collection of contamination and subsequent treatment of the radioactive waste for on-site 

disposal for a typical LANL hot cell involved the following procedures: 

• Removable contamination was spray-washed from containment structures, such as bench tops and 

laboratory exhaust hoods, and from equipment and tools and then vacuumed into holding 

containers. 

• Spray washing to remove loose contamination was repeated until levels allowed personnel to 

enter the hot cells for short periods to apply more aggressive measures such as acid washing and 

scrubbing to lower contamination to acceptable levels. 

• Soaking highly contaminated, smaller equipment and tools in containers filled with a mixture of 

CH2Cl2 (dichloromethane or methylene chloride), detergents, and hot water. This was an 

effective means of removing radioactive residues. The foaming action of the mixture carried off 

much contamination in precipitates that were collected for treatment and/or disposal. 

• Dry solid residues and debris were vacuumed with in-cell vacuum systems and collected in 

containers. Recovered material considered to be of value was sent for further separation, 

analysis, and recycle. 

• At Ten Site (TA-35 hot cells), highly radioactive residues were evaporated to dryness, placed in a 

pressure-sealed, aluminum containers, and loaded into uranium casks. The casks were then 

loaded on trucks and transported to the TA-21 disposal area for burial in 2-ft diameter by 15 ft 
8-12 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 8

deep holes in the ground. When burial activities at TA-21 ceased, LANL began using the burial 

grounds at TA-54 to meet their disposal requirements for these wastes. 

• Highly radioactive solid waste was loaded into aluminum or stainless steel containers and placed 

in uranium casks for burial at the TA-21 disposal area. In later years, these wastes were 

transported to the burial grounds at TA-54. During the early period of the 1950s and 1960s, 

liquid wastes were mixed with concrete and vermiculite and buried as solid waste. 

• At the Wing 9 facility (TA-3 hot cells), cells dedicated to uranium and plutonium fuel work used 

open containers inside the hot cells. Dry debris and dust generated from cutting, crushing, and 

drilling the fuel were collected with an in-cell vacuum system equipped with a cyclone separator, 

a CWS filter, and a charcoal adsorption bed. Liquid and solid wastes were collected, treated, and 

consolidated for land burial using similar methods as those described above. 

• By the 1970s, liquid wastes with recoverable amounts of radioactive materials were sent to hot 

cells at TA-50 for separation (such as cation exchange processing), analyzed, and returned to Lab 

generators for reuse and/or further analyses. Waste contents with 10-3 μCi mL-1 alpha and/or 10-2

μCi mL-1 beta concentrations were disposed of as low-level radioactive waste. If concentrations 

were above these values, the waste was placed in portable stainless steel tanks and delivered to 

the TA-50 Waste Treatment facility for recovery and consolidation (LANL, 1974). 

References 

Buckland C., 1964. “Summary of 131I Concentrations In and From New Cell Addition at TA-48.” 

memorandum. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. October 14, 1964. 

Repos. No. 1181. 

Dummer J.E. 1961. “Iodine Activity from DP West Hot Cells”, memorandum, H-1-D-12), Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. July 25, 1961. Repos. No. 811. 

Dummer J.E. 1965. “Hot Cell Decontamination Procedure at the Los Alamos Scientific Laboratory”, 

memorandum. . Los Alamos Scientific Laboratory, Los Alamos, New Mexico. January 5, 1965. 

Repos No. 4543. 

Dummer J.E., A.M. Valentine 1979a. Monthly Progress Report Area Health Physics, February 1979. 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. March 1, 1979. Repos. No. 5473. 

Dummer J.E., A.M. Valentine 1979b. Monthly Progress Report Area Health Physics, May 1979 . Los 

Alamos Scientific Laboratory, Los Alamos, New Mexico. June 1979. Repos. No. 5477. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 88-13

Table 8-1. Hot Cell Operations at Los Alamos National Laboratory (Wilson et al. 1979) 

TA Purpose Dates Radionuclides/Chemicals 

1 Radiochemical and radiotracer separation (including RaLa operations) and neutron source preparation. Most of these operations took place in H Building. 1944 -1957 140Ba, 140La, 90Sr,. 210Po, 226Ra, Be 3 

CMR Building Wing 9 Hot Cell Facility. Used to evaluate irradiated plutonium and uranium fuel and fission products testing and separation and post detonation debris radiochemical analyses. Operations occurred largely in Wing 9 of CMR Building. The facility contained 16 general purpose cells 2m by 2m by 3.6m high.

1961-present 

239,238Pu, 234,235,238U, mixed 

fission products, mixed 

activation products, TRU 

10 

Early RaLa sources were prepared in Bayo Canyon and later in facilities at Ten Site (TA-35). RaLa explosive experiments were completed in Bayo canyon. Remote handling, telescopes, and mirrors were used to aid in the separation and preparation of the 140La. A few hundred thousands curies were handled during 

almost 20 y of RaLa explosive testing. Some batches of La reached upwards to 5,000 Ci. Single sources for test shots ranged from 40 to over 3,000 Ci. 

1944-1951 

140Ba, 140La, 90Sr,. 210Po, 

226Ra, Be 

18 Rover Program - Hot Cell facility 1955-1973 Pu, U, and fission products21 

Examination of irradiated Pu and enriched uranium from Omega reactor (such as 235U impregnated with 

graphite and 239Pu in stainless steel casing and a tantalum sheath) and separation of irradiated fuel and fission 

products. The facility had four primary hot cells that were designed primarily to evaluate plutonium reprocessing schemes. Fuel reprocessing experiments and tests were discontinued in 1967. In the 1970s, the hot cells were used to evaluate irradiated fuel elements associated with the LMFBR program. Operations 

occurred largely in Bldg 4, Room 401. Rooms 403 through 407 contained gloveboxes used for metal preparation of 238,239Pu. High exposure rates during material transfers to hot cells. After tests were 

completed, irradiated fuel was transferred from hot cells to the “hot dump.” On 26 May 1961, special fiberglass filter papers were placed in cell, corridor, and stack exhaust lines in Room 401 to sample air for fission products. 

1958 - 1978 

3H, 239,238Pu, 234,235,238U, 

mixed fission products 

33 Tritium handling facilities that contained hot cells for source handling and processing. 3H 35 

Radiochemical and radiotracer separation (RaLa operations), neutron source preparation, and fuel separation. Starting in 1956, the Chemical Processing Plant at Idaho Falls provided purified 140Ba. Almost 2 million Ci 

were processed at Ten Site by 1963 when the RaLa program was terminated. Irradiated fuels from the 

LAPRE I and II and LAMPRE reactors were also evaluated in hot cells located at Ten Site. First hot cell design after WWII for handling high-level radioactive materials. 

1951-1963 

140Ba, 140La, 90Sr,. 210Po, 

226Ra, mixed fission 

products, Be 

48 

Radiochemistry Hot Cell Facility. Used to perform actinide chemistry and isotope production/separation. Facility also used to analyze samples collected from nuclear weapon test shots. In 1963, another hot cell facility was built in an adjacent structure to evaluate and dissolve samples of graphite fuel from the Rover Program. The Rover Program ended in 1973. 

1959-present 

Pu, U, TRU, mixed fission 

products, and mixed 

activation products 

50 

Contaminated Hot Cell facility. This facility was designed to handle high-level beta and gamma emitting wastes from several groups at LANL. The hot cells were part of the Contaminated Waste Treatment Plant. The cell was primarily used to neutralize liquid waste and package it for permanent storage. 

1963-present 

Pu, U, TRU, mixed fission 

products, andmixed 

activation products 

52 UHTREX high-level remote handling area consisted of one hot cell for fuel element changing and examination. 1961-1968 Pu and U 53 LAMPF and LANSCE facilities contain two hot cells used for radiochemical experiments of irradiated targets, isotope production, and mixed activation products. 1976-present 3H, mixed activation products 
8-14 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 8

Enders J. 1970. “Additional Information to Report on CMR Building Stack Discharge for 1967, 1968, 

and 1969”, memorandum. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. April 6, 

1970. Repos. No. 1051a. 

Hyder J.W. 1992. LANL memorandum regarding T-48 hot cell contamination and effluent and filtration 

methods. Los Alamos National Laboratory, Los Alamos, New Mexico. 1992. Repos. No. 

1214a. 

LANL 1999. Wing 9 Hot Cell Support Work Involving Highly Radioactive Materials. The Actinide 

Research Quarterly, Nuclear Materials Research and Technology. Los Alamos National 

Laboratory, Los Alamos, New Mexico. First quarter 1999. Repos. No. 7675.

LANL 1974. Radioactive Waste Management Site Plan. Los Alamos Scientific Laboratory, Los Alamos, 

New Mexico. June 1974. Repos. No. 2003. 

LASL 1975. Radioactive Waste Management Site Plan. Los Alamos Scientific Laboratory, Los Alamos, 

New Mexico. June 1974. Repos. No. 5553. 

Lawrence J.N.P. 1970. “Evaluation of Air Sample for 131I”, memorandum. Los Alamos Scientific 

Laboratory, Los Alamos, New Mexico. January 14, 1970. Repos. No. 1051a. 

Maestas S. 1967. “TA-48 Contamination Survey, Week of May 1-5, 1967” memorandum, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. May 11, 1967 Repos. No. 1174. 

Maestas S. 1969. “H-1 Weekly Report of Radioactive Contamination for TA-48.” Memorandum. Los 

Alamos Scientific Laboratory, Los Alamos, New Mexico. January 7, 1971. Repos. No. 1219. 

Maestas S. 1970. “H-1 Weekly Report of Radioactive Contamination for TA-48.” Memorandum. Los 

Alamos Scientific Laboratory, Los Alamos, New Mexico. January 7, 1971. Repos. No. 1219. 

Maestas S. 1971. “H-1 Weekly Report of Radioactive Contamination for TA-48.” Memorandum. Los 

Alamos Scientific Laboratory, Los Alamos, New Mexico. January 7, 1971. Repos. No. 1219. 

Meyer, D. 1970. “Exhaust System Activity, CMR Building.” memorandum. Los Alamos Scientific 

Laboratory, Los Alamos, New Mexico. February 19, 1970. Repos. No. 1051a. 

Valentine A. F., L. Fitzgibbon, L. Martinez. 1968. Health Physics at the Los Alamos Wing 9 Hot Cell 

Facility. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. LA-4074, December 

1968. Repos. No. 2063. 

Wilson M.T., W.T. Wood, J.W. Barnes 1979. “History of Remote Handling at the Los Alamos Scientific 

Laboratory.” Los Alamos Scientific Laboratory Report LA-UR-79-3091. Los Alamos, New 

Mexico. Repos. No. 7674. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 9 9-1

Chapter 9: Operations with Other Radionuclides 

Uranium 

As discussed in numerous places in this report, uranium, at various levels of 235U enrichment, has been 

used in a wide variety of applications at Los Alamos. 

Uses of Uranium in Weapons 

To develop and build gun-assembled weapons, Los Alamos personnel initially experimented with use of 

enriched uranium (235U) and plutonium as the fissionable material. The gun-assembled uranium weapon 

was carried into production, and some implosion-assembled weapons that came along later included 

uranium as a fissile material. In addition, heavy metals such as uranium were used as “tampers” that 

confined the explosion, reflected some neutrons that would otherwise escape, and thereby decreased the 

“critical mass” of fissile material required to achieve an atomic explosion (Serber et al. 1992). 

Uses of Uranium in Reactors 

Uranium was also used in liquid and solid forms as fuel in various forms of nuclear reactors. More details 

can be found in Chapter 5. The first Water Boiler reactor was assembled in late 1943 at Omega Site (TA2), using the nation’s total supply enriched uranium as its fuel in the form of 14%-enriched uranyl sulfate. 

The Plutonium Fast Reactor (Clementine) used plutonium fuel that was surrounded with a 6-inch thick 

natural uranium reflector, and reactivity control was achieved via insertion of uranium fuel rods. The 

LAPRE I reactor experiment studied the use of phosphoric acid solutions of high-enriched uranium in a 

high-temperature reactor fuel, as did LAPRE II. The Ultra High Temperature Reactor Experiment 

(UHTREX) used 93%-enriched uranium fuel in the form of small spheres of UO2 coated with pyrolytic 

carbon and bound in a graphite matrix. That fuel was fabricated at the CMR Building in TA-3. A 1969 

waste management plan says that the DP East facility processed new Rover fuel elements containing 

enriched uranium. 

Facilities that Handled Uranium 

From 1948 to 1960, DP West Site’s Building 4 housed laboratories for production of enriched uranium 

hydride. In 1960, the hydride equipment was removed so that a hot cell could be added for the 

examination of irradiated plutonium and enriched uranium fuel elements. 

Facilities at the Original Technical Area (TA-1) that housed uranium operations included:
9-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 9

• C Building– housed a normal machine shop with a uranium machine shop in southeast section. 

Became operational in October 1943. 

• D-Building– a facility designed to carry out chemistry and metallurgical experiments on 

plutonium and uranium. Other activities included design of tampers and polonium initiators and 

development of various refractory materials. 

• G Building– housed the uranium and graphite “Sigma Pile”, plus leak-testing of radium sources. 

Removed 6/59. 

• HT Building– heat treatment and machining of normal and enriched uranium. 

• HT Barrel House– contained storage areas for 239Pu and 235U. 

• M Building– housed processing, metallurgy, and recovery of enriched uranium. 

• Sigma Bldg– housed casting, machining, powder metallurgy of normal and enriched uranium, 

thorium (eastern part was normal; western part was enriched). 

• TU Building– housed machining of normal uranium (“tuballoy”). 

• TU-1 Building– housed recovery of enriched uranium. 

• V Building– contained the original machine shop; uranium and beryllium were machined there. 

The Sigma Complex in TA-3, built in the 1950s and 1960s, has housed extensive laboratory areas for 

materials synthesis, and processing, characterization, and fabrication of materials such as beryllium, 

uranium, thallium, and aluminum alloys. These activities have included large-scale metallurgy and 

fabrication of normal and fully enriched uranium. As of 1969, the CMR Bldg, except for its Wing 9, was 

used for laboratory work on small quantities of uranium and plutonium. Wing 9 contained hot cells for 

handling of irradiated uranium and sometimes plutonium (see Chapter 8). 

Uses of Uranium in Explosive Testing 

LASL staff estimated in 1971 that between 75,000 and 95,000 kg of uranium had been expended in 

experimental shots at the Lab from 1949 through 1970 (Drake and Eyster 1971). Normal uranium was 

used until 1954, after which depleted uranium was used exclusively. A 1952 AEC report states that test 

shots at LASL routinely dispersed 300 lbs of uranium per month and 200 lbs of barium per month 

(English 1952). Between 1944 and 1948, eight firing sites (A-H) were established at TA-15 (R-Site). 

Experiments using from 50 lb up to 2 tons of HE were conducted at these firing points. Firing points E 

and F were the most active. Up to 65,000 kg of uranium and 350 kg of beryllium were expended at these 

two firing sites. Hazardous materials, including uranium, beryllium and lead, were largely left in place at 

these sites where after they were deposited by the explosion (LANL 1992). 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 9 9-3

The Bayo Canyon Site (TA-10) was used between 1944 and 1962 for experiments using conventional 

high explosives, radioactive lanthanum (RaLa), and in some cases depleted or natural uranium. The 

explosions resulted in the dispersion of uranium, 140La and 90Sr in the form of aerosols and debris to the 

atmosphere and onto the ground. 

Use of Uranium at LAMPF / LANSCE 

Originally constructed to study sub-atomic particles, the Los Alamos Meson Physics facility (LAMPF) 

includes an accelerator that has been used to generate intense pulses of neutrons by sending protons into 

targets of high atomic number such as uranium. 

Accidents and Incidents Involving Uranium 

In addition to routine, operational releases of uranium, some of the accidents and incidents that are 

described in LANL documents involved uranium and could have been associated with airborne and/or 

waterborne releases to the environment. Some of the documented accidents that that have involved 

uranium are summarized in Table 9-1. 

Evaluation of Potential Health Risks from Atmospheric Releases of Uranium 

As summarized above, the main areas where uranium has been used in machining or fabrication include 

the original technical area (TA-1), TA-3, and TA-21. Considerable quantities of uranium have also been 

expended in firing site activities conducted at TA-15, TA-36, and others. LANL’s operations have 

involved a wide range of uranium enrichment, from depleted (primarily 238U, with very little 235U) to 

highly enriched (primarily 235U). 

To gauge what impact LANL’s atmospheric uranium releases may have had in terms of human health 

risk, the NCRP Report No. 123 screening model was applied to airborne uranium source term information 

for a given year (NCRP 1996). The year selected was 1972, for which LANL reported a relatively large 

release of 1,200 μCi of U-234/U-235 from TA-21 (LASL 1973). 

The 1972 uranium release was screened against a criterion of a 1 in 100,000 added risk of fatal or nonfatal cancer, assuming a risk factor of 6% per sievert (Sv). This corresponds to a dose equivalent of 

1.67×10-04 Sv (16.7 mrem). The exposed population selected was the residential area nearest the release 

point. In the case of TA-21 this was the residential apartments within the townsite, at an estimated 

distance of 1,460 m. The pathways considered for the residential location were inhalation of 

contaminated air, plume immersion, irradiation from contaminated ground, and consumption of 
9-4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 9

Table 9-1. Some accidents and incidents at LANL that involved uranium 

Date Description Repos. 

No. 

2/1/1951 

On February 1, 1951 there was a criticality incident involving 2 cylinders of U-235. The cylinders 

weighted 24.4 kg and 38.5 kg of 93% U-235. The 2 cylinders were in a water reflected system. 

There was slight oxidation of the uranium. 1017 total fissions were involved. 

6206 

12/9/1952 On December 9, 1952 in S-104 uranium in a furnace caught fire and was contained in the furnace. 

Clean-up of S-104 was conducted on December 11 and 12. 3495 

6/26/1953 On June 26, 1953 there was a small fire in a flask containing uranium hydride in D-151. 3491 

12/5/1953 On December 5, 1953 a glass furnace in a vacuum hood exploded releasing 40g of uranium. 3491 

3/9/1955 Uranium was released into the hood of Room 121 at TA-46 on March 9, 1954. 2383 

5/12/1955 On May 12, 1955 a small furnace erupted releasing an unknown quantity estimated at less than one 

kilogram of uranium in Room 102 of Sigma Building. 2374 

7/21/1955 On July 21, 1955 some normal uranium caught fire in Room 1131. 1184 

8/19/1955 On August 19, 1955 an employee dropped a test tube containing one gram of normal uranium in 

Wing 2 of CMR Building. 3489 

3/9/1956 On March 9, 1956 a spill of uranium flowed into the bottom of the furnace in Room 21 of the Sigma 

Building. 2383 

9/27/1957 On September 27, 1957 rags contaminated with sodium and uranium caught fire in Room 133 at Ten 

Site. Fire was quickly extinguished with CO2. 2414 

4/1/1959 During processing of irradiated U-235 at TA-48 uranium oxide was blown out of the hood when a 

sample can was opened. 2514 

12/3/1959 On December 3, 1959, a fire broke out in the duct work of Room 313 of DP West where uranium 

materials are incinerated. The damage was limited to the duct work. 2494 

6/17/1960 

On June 17, 1960 there was a criticality incident involving ~48 kg U-235. Uranium cylinders in thick 

graphite (9-in.) reflected before complete assembly, resulting in trivial damage. 6 x 1016 total fissions 

were involved. 

6206 

8/7/1961 On August 7, 1961 a container with a uranium fuel element leaked. Contamination products were 

detected in the parking lot and around the building. No decontamination was done. 2524 

4/8/1963 On April 8, 1963 there was a uranium spill at TA-46. 2536 

1/10/1964 On January 10, 1964 in SM-66 depleted uranium residue ignited in a drum. The material was allowed 

to burn out. 2812 

4/22/1964 An explosion occurred following a fire in Room 313 DP West from uranium contaminated rags on 

April 22, 1964. The fire spread from the drybox to the adjoining hood. 2505 

6/1/1965 

At DP East the gas purge line to a recovery furnace became plugged. The operator in charge removed 

a rubber hose connected to the unit, and uranium-containing dust was blown out into his face and onto 

his clothing. 

NA 

11/16/1966 The air cleaner at one of the enriched uranium shops developed a pin-hole leak, which resulted in 

high surface contamination of the surrounding area. NA 

1/15/1969 A glovebox explosion occurred in the uranium recovery operation at DP West, during the incineration 

of U-235 metal turnings. NA 

4/3/1970 On April 3, 1970 a furnace containing uranium exploded releasing dust in SM-35 Room 104. 4261 

11/2/1971 On November 2, 1971 an explosion in test cell furnace blew uranium contamination onto floor. 1417 

5/4/1979 

A stainless steel pot containing uranium tritide was overheated in a laboratory at the Cryogenics 

Building and ruptured on May 4, 1979. tritiated water escaped into the laboratory because of 

inadequate air flow in the hood. Some tritium was released to the atmosphere. 

4484 

11/2/1982 

On November 2, 1982 approximately 50-100 L of waste liquid escaped from a tank vent at TA-21-

257 contaminating the building roof, walls, and surrounding area with low levels of plutonium, 

americium, and uranium. 

NA 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 9 9-5

contaminated soil and vegetables. Consumption of locally raised meat or milk were not considered. The 

applicable NCRP 123 screening factors for the selected pathways were 0.31 Sv per Bq per m3

 and 0.33 Sv 

per Bq per m3

 for 234U and 235U, respectively. Inhalation is the dominant contributor to both factors, being 

93% of the total for 234U and 80% for 235U. For simplicity the release was screened as 100% 235U. A 

bounding value for the air diffusion factor was selected based on the source-receiver difference. This was 

conservative and avoided the need to account for effective release height and building wake effects. 

The NCRP Report No. 123 screening evaluation for the 1972 airborne uranium release from TA-21 gave 

a screening value of 1.7×10-6 Sv (0.17 mrem), much smaller than the screening criterion. The screening 

dose was also compared against screening criterion reduced by a factor of ten, as recommended by NCRP 

123 to account for uncertainties. This gives an adjusted screening value of 1.67×10-5 Sv (1.67 mrem), 

still much larger than the screening dose. Thus, a significant human health risk (relative to the selected 

risk criterion) is not indicated for the relatively large uranium release reported for TA-21 for 1972. It 

should be noted the release value was used as reported by LANL and has not been adjusted in any way or 

independently verified. Adjustments for biases such as sample line losses or counting losses from the 

material being buried in the collection media would increase the amount of material released, but not by 

enough in this case to exceed the screening criteria. 

A screening evaluation was also performed for depleted uranium (DU). The effluent data for 1973 were 

used, with a release of 640 kg of DU from TA-3 (LASL 1974). On an activity basis, this equates to a 

release of 2.11×105

 μCi, assuming the material was 100% 238U (specific activity = 0.33 μCi/g). The 

airborne DU release reported for TA-3 was assumed to have originated from the Sigma Complex. The 

Sigma Complex consists of the Sigma Building (SM-66) and other facilities involved in uranium 

operations. The nearest residential area was determined to be the Western Area at a distance of about 

1,040 m. As with the screening for TA-21, a bounding value of the diffusion factor at that distance was 

used for simplicity. The NCRP 123 screening factor for 238U for the applicable pathways is 0.29 Sv per 

Bq per m3

. 

The NCRP 123 screening evaluation for the 1973 airborne DU release from TA-3 gave a screening value 

of 4.4×10-4 Sv (44 mrem). This value exceeds the screening criterion without adjusting it to account for 

uncertainties, indicating further investigation into potential health risks is warranted. As with the 

evaluation for TA-21, the release value was used as reported by LANL and has not been adjusted in any 

way or independently verified. 
9-6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 9

It seems counterintuitive that DU releases would screen so much higher than 235U, but that result reflects 

the large quantities of DU processed at Los Alamos over its history. DU was also expended in substantial 

quantities in dynamic experiments at firing sites such as TA-15 and TA-36. 

To follow-up on the result of the DU screening, the maximum average air concentration values reported 

by LANL’s ambient environmental air monitoring network for 1973 were evaluated in terms of the 

screening dose they represented. The maximum annual average reported for offsite locations was 0.2 ng 

m-3 (LASL 1974). This value was seen at three of the 26 off-site and perimeter monitoring stations: 

Acorn Street, Bandelier headquarters, and White Rock. The maximum annual average for the on-site 

monitors was 0.3 ng m-3, measured at TA-52 (LASL 1974). Assuming the measured air concentration 

values reflected 235U activity (the conservative choice), applying the NCRP Report No. 123 screening 

factor for 235U to the maximum offsite average for 1973 (in consistent units) gave a screening dose of 

5.4×10-6 Sv (0.54 mrem). This is well below the screening criterion of 1.67×10-4 Sv even if the order of 

magnitude adjustment is applied to account for uncertainties. Treating the measured concentration as 238U 

would give an even lower screening dose. 

The above evaluations do not paint a clear picture of the potential for health risks to Los Alamos residents 

from historical atmospheric releases of uranium. NCRP Report No. 123 screening evaluations have 

indicated enriched uranium releases were not significant in terms of potential risk relative to the 1 in 

100,000 criterion selected, and showed releases of depleted uranium warranted further investigation. The 

ambient air monitoring data for 1973 did not suggest significant risk. None of these evaluations, 

however, consider releases from earlier in LANL’s history. Earlier releases may have been much larger 

than those from the 1970s forward for which atmospheric effluent data are conveniently summarized. 

Beyond the need to compile data from a large volume of individual references, asserting uranium releases 

from the earlier years is further complicated by the fact much of the available effluent data were reported 

in terms of gross alpha or beta activity, rather than for specific isotopes. These data would need to be 

evaluated using process knowledge to assign the gross measurements to specific isotopes. Further, the 

fact uranium releases were a chronic source of exposure involving a material strongly retained in the 

human body may warrant a more detailed evaluation than can be achieved through the screening methods 

used here. Thus, further investigation would be needed before a more conclusive assessment could be 

made of the potential for health risks to local residents from atmospheric uranium releases from Los 

Alamos. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 9 9-7

Radioactive Lanthanum (RaLa) Operations 

Barium/lanthanum is a mixture of 140Ba and its daughter product 140La . 140La is the isotope that was used 

by LANL in the years between 1944 and 1962 as an aid in “hydrodynamic tests” conducted primarily to 

perfect the implosion process. 140La has a 40-h half-life, a strong gamma emission, and “grew into” the 

140Ba that was produced in large quantities in the Clinton Pile at X-10 Site in Oak Ridge (Widner 2000, 

Widner and Flack 2002) and later at the Idaho National Engineering Laboratory. RaLa was used in 

implosion testing from 21 September 1944 through 6 March 1962 (Dummer et al. 1996). All RaLa 

implosion tests were conducted in Bayo Canyon (TA-10), which is shown in Fig. 9-1. Fig. 9-2 depicts 

the location of the buildings and firing points within TA-10. 

Fig. 9-1 . Bayo Canyon Site, TA-10, in 1950. View is toward the west. 

Photo ERID-018982 courtesy of LANL 
9-8 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 9

Fig. 9-2. Layout of TA-10, Bayo Canyon

From 1944 to 1950, the RaLa sources were prepared at the TA-10 Chemical Processing Building. 

Preparation of the RaLa sources was moved to TA-35 (“Ten Site”) for the period of 1951 through 1963 

and operated by group CMR-10. The 140La sources were placed in shielded containers and trucked to the 

firing site where they were remotely loaded to the explosive test assemblies. 

In order to obtain data on implosions, laboratory personnel had previously conceived a procedure by 

placing a gamma ray source at the center of a spherical implosion assembly. The emitted gamma rays 

would travel outward radially, through both the collapsing shell and the high explosive. The increased 

compression of the metallic shell during implosion would cause the gamma rays to be increasingly 

absorbed. The gamma rays would monitored by detectors set around the high explosives. The monitored 

data would provide data on the density changes in the collapsing shell, the time of collapse, the degree of 

compression, and symmetry by comparing the gamma rays intensity in different directions. A mixture of 

140Ba and 140La would be used as the gamma ray source. Due to the potential post-experiment radioactive 

problems, 140Ba was removed from the mixture. 

140La was initially provided by Oak Ridge as a mixture of 140Ba and 140La. Chemists at the TA-10 

Chemical Process Building prepared RaLa sources by separating a solution containing the parent barium-
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 9 9-9

140 and other impurities such as 89Sr and 90Sr. The separated RaLa, along with unavoidable small amount 

of barium and strontium, was then encapsulated as specified by each experiment—sometimes in a metal 

sphere no larger than a match head (a pure 1,000-Ci 140La source weighs 0.8 mg). 

The explosive test assemblies used surrogate materials with mechanical properties similar to plutonium. 

Uranium, although used, had the disadvantage of being a strong gamma-ray absorber. Metals such as 

iron, copper, or cadmium were used, and most of the early shots employed cadmium (Dummer et al. 

1996). The implosion assembly was surrounded initially by a number of ionization chambers (see Fig. 9-

3) and later by scintillation detectors. 

Fig. 9-3. Ionization chambers surrounding a RaLa shot on 13 May 1947 

Table 9-2 lists, by year, the number of test shots and the amount of RaLa involved. A total of 254 tests 

were conducted between 1944 and 1962, with RaLa sources ranging in size from about 25 Ci to 7,090 Ci. 

The explosions resulted in the dispersion of the metallic shell (uranium or other material such as 

cadmium) and the radioactive RaLa and residual impurities such as 140Ba and 90Sr, in the form of aerosols 

and debris to the atmosphere and onto the ground. 

The preparation of the RaLa conducted at TA-10 generated liquid and radioactive wastes which were 

disposed of in subsurface pits and leaching fields at the site. Almost 2 million curies of 140Ba had been 

handled at TA-10 and TA-35 by the time the RaLa program was terminated in 1963. The TA-10 site was 

decommissioned by 1963 and transferred to Los Alamos County on July 1, 1967 (Mayfield et al. 1979). 

In addition to the release of RaLa, about 226 mCi of Strontium-90 was reported released; over 80% of the 

226 mCi was released in seven shots in 1945 (Dummer et al. 1996). In a dose assessment conducted by 

LANL personnel, the highest annual dose from the RaLa shots (17 mrem) was calculated to have 
9-10 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 9

occurred in 1955. The calculated dose for those who were in Los Alamos during the experiments ranges 

from 110 mrem to 450 mrem (Mayfield et al. 1979, Dummer et al. 1996, Kraig 1997). None of these 

dose assessments have been independently critiqued by the LAHDRA team. 

Table 9-2. Annual quantities of radioactive lanthanum used in RaLa shots at Bayo Canyon

Year Quantity of RaLa Used (Ci) Number of Shots 

1944 1,112 10

1945 18,363 36

1946 20,556 24

1947 22,734 27

1948 12,236 19

1949 28,255 26

1950 19,788 12

1951 0 0

1952 6,370 4

1953 1,065 4

1954 15,580 13

1955 40,763 21

1956 35,976 21

1957 17,358 9

1958 9,845 7

1959 8,322 8

1960 5,560 5

1961 24,312 5

1962 13,607 3

Totals 301,802 254 

During March and early April 1950, the Air Force sought to conduct independent studies of airborne 

radioactivity (Dummer et al. 1996). They selected three of the 254 RaLa experiments (Shots 147, 148, 

and 149) and used a B-17 aircraft to track and measure radioactivity in the cloud resulting from them. In 

July 1950, LANL provided the Air Force with a static 400 Ci RaLa source for additional analysis. The 

source was transported to an area near Abiquiu, about 22 air miles north of Los Alamos, and seven passes 

were made by an airplane over the stationary source (Dummer et al. 1996). 

Polonium Operations 

Polonium was used in atomic bomb initiators, utilizing the (α,n) reaction of 210Po and 9Be to generate 

neutrons. In February 1945, schedule for polonium delivery from Monsanto to the Original Technical 

Area was increased to 100 Ci per month by June and 500 Ci per month by December (Hoddeson et al. 

2004). At TA-1, polonium was handled in D Building, H Building, and Gamma Building. DP East Site 

began operation in September 1945 and contained Buildings 151, 152, and 153. Building 155 was 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 9 9-11

completed in December 1949. It is reported that “the well-designed DP polonium plant went into 

operation sooner than did the plutonium plant” [DP West site; TR 6704, Box 6 of 8]. The DP East Site 

facilities were used to process polonium and actinium and to produce initiators. 

At DP East, Building 21-153 exhausted air from the main buildings at DP East, was constructed similarly 

to Building 12, and was in service until March 1970. The primary radioactive contaminant of this filter 

house was 227Ac. Bldg. 153 had transitional plenums and filter housings for electromatic filters, two 

blowers, and two stacks. Stack monitoring data for DP East Site have been located in CMR-12 monthly 

progress reports starting in August 1945. The data are presented as average counts per minute per liter 

over each month for DP East Stack 1 and Stack 2. These data are for alpha-emitting radioactivity, with 

no isotopic composition indicated through at least 1949 (CMR-12 Progress Reports 1945-1949). 

Polonium was also expended in explosive testing at Los Alamos. For example, TA-33 (Hot Point or HP) 

Site was developed in 1947 for the Laboratory’s weapons testing group as a substitute test site for 

experiments that were being conducted at Trinity Site in southern New Mexico (McLain et al. 2001). 

These tests used conventional high explosives as well as uranium, beryllium, and polonium radiation 

sources. Experiments that were conducted primarily to verify designs of nuclear weapon initiators were 

performed in underground chambers and on surface firing pads. Additional tests were carried out at TA33 firing sites equipped with large guns that fired projectiles into earthen berms. The documents 

associated with LAHDRA Repository Numbers 2375, 4519, 6523, and 7021 provide details of events at 

TA-33 that resulted in releases of polonium from tests at TA-33 in the 1950s. 

On 8 January 1953, it was discovered that a mock fission source containing polonium and beryllium had 

ruptured at Pajarito Site (TA-18) and contamination had spread to the housing area (Shipman 1953). 

Possibly as much as 2 Ci of polonium was lost, that greater part of which was thought to have remained in 

and around the laboratory at Pajarito Site. However, “significant amounts [of polonium] were found in a 

number of homes.” Among the items found to be contaminated in a “large number” of homes were shoes, 

clothing, floor coverings, vacuum cleaners, children’s toys, and baby diapers. Rugs and upholstered 

furniture presented serious problems with decontamination.

On 3 August 1955 a Po:Be neutron source ruptured, resulting in the contamination of 150 staff members 

in Building SM-40 (Shipman 1955). A mock fission polonium source containing 25.2 Ci of polonium 

exploded in the basement of the Physics Building, and contamination was spread through out the 

building. It was 5 days or more before most personnel could return to work. The report states that air 
9-12 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 9

samples for the area never exceeded "3 times tolerance." Although it was said that no activity reached 

homes or personal vehicles, a "few" government vehicles were contaminated. 

References 

Drake RW, Eyster EH. Memorandum from E.H. Eyster to G.L. Voelz: Uranium dispersed by 

experimental test shots at Los Alamos. 1971. Repos. No. 1412. 

Dummer JE, Taschner JC, Courtwright CC. The Bayo Canyon radioactive lanthanum (RaLa) program. 

Los Alamos, NM: Los Alamos National Laboratory; LA-13044-H; 1996. Repos. No. 0002. 

English SG. Project Crave: Survey of the U.S. Atomic Energy Commission Operations and Facilities. 

Brookhaven, NY: Brookhaven National Laboratory; BNL-157; 1952. Repos. No. 611. 

Hoddeson L, Henriksen PW, Meade RA, Westfall CL, Baym G, Hewlett R, Kerr A, Penneman R, 

Redman L, Seidel R. Critical Assembly: A Technical History of Los Alamos During the 

Oppenheimer Years, 1943-1945. New ed. Cambridge University Press; 2004. 

Kraig DH. Dose reconstruction for weapons experiments involving 140La at Los Alamos National 

Laboratory, 1944-1962. Health Phys 73: 620-8; 1997. 

LANL. RFI Work Plan for Operable Unit 1086. Los Alamos, NM: Environmental Restoration Program, 

Los Alamos National Laboratory; LA-UR-92-3986; 1992. Repos. No. 4387. 

LASL. Environmental Monitoring in the Vicinity of the Los Alamos Scientific Laboratory. Los Alamos, 

NM: Los Alamos Scientific Laboratory; LA-5184; 1973. Repos. No. 887. 

LASL. Environmental Surveillance at Los Alamos During 1973. Los Alamos, NM: Los Alamos National 

Laboratory; LA-5586; 1974. Repos. No. 2161 

Mayfield DL, Stoker AK, Ahlquist AJ. Formerly Utilized MED/AEC Site Remedial Action Program, 

Radiological Survey of the Bayo Canyon, Los Alamos, NM. Washington, DC: U.S. Department 

of Energy; DOE/EV-0005/15, UC-71; 1979. Repos. No. 2247. 

McLain AD, McHehee ED, Garcia KM. Decontamination and Decommissioning of Buildings 1, 2 and 40 

at Technical Area 33. LA-UR-01-5308; 2001. Repos. No. 7858. 

NCRP. Screening Models for Release of Radionuclides to Atmosphere, Surface Water, and Ground. 

Bethesda, MD: National Council on Radiation Protection and Measurements; NCRP Report No. 

123; 1996. 

Serber et al. The Los Alamos Primer - The First Lectures on How to Build a Bomb; Contains an 

annotated version of report LA-1, "The Los Alamos Primer" (1943). Berkeley, CA: University of 

California Press; 1992. 

Shipman TL. H Division Monthly Progress Report, December 20, 1952 - January 20, 1953. Los Alamos, 

NM: Los Alamos National Laboratory; 1953. Repos. No. 2276. 

Shipman TL. H-Division Progress Report, July 20, 1955- August 20, 1955. Los Alamos, NM: Los 

Alamos Scientific Laboratory; 1955. Repos. No. 2377. 

Widner TE. Oak Ridge Dose Reconstruction project summary report. Alameda, CA: ChemRisk, a Service 

of McLaren/Hart, Inc.; 2000. 

Widner TE, Flack SM. Dose Reconstruction for Radionuclides and Chemicals: Case Study Involving 

Federal Facilities at Oak Ridge, Tennessee. Chapter 13. Human and ecological risk assessment 

theory and practice: 735-869; 2002. 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-1

Chapter 10: The Trinity Test 

During the first six months of development work at the Laboratory, the gun method of assembly was the 

focus of the ordnance program. Up to August 1944, the main focus of activity was the plutonium gun. 

By August 1944, the high velocity uranium gun had been thoroughly proved in principle but the 

plutonium gun assembly program was abandoned. The main effort of the Laboratory was now directed to 

the mounting difficulties of the implosion program. The proposal for implosion assembly was to use a 

plastic flow tamper and active material under high-explosive impact. The first advantage of the implosion 

weapon over the gun weapon was its much shorter time of assembly. This was of special importance for 

the assembly of plutonium due to its expected high neutron background, which would make predetonation 

a serious danger (Hawkins 1961). The implosion-assembled, plutonium-based designi

 was by far the 

more complicated than the gun-assembled design. A test of that device was considered necessary because 

of the “enormous step” from theory and experiments to production of a combat weapon and the 

realization that, if the device failed over enemy territory, “the surprise factor would be lost and the enemy 

would be presented with a large amount of active material in recoverable form.”ii

 

Document Review 

Internal Los Alamos technical reports (many with LA- and LAMS- prefixes) in the LANL Reports 

Collection and the document holdings of the LANL Records Center and Archives were the primary 

sources of information about the development of the implosion weapon and the Trinity test program. 

These collections were reviewed and copies of relevant documents were requested for public release. 

Information from interviews with Trinity participants, Web sites, the Nuclear Testing Archives in Las 

Vegas, news archives, and books available from the popular press were also incorporated into this 

summary of information regarding the Trinity test. 

Preparations for the Test 

Test Organization 

A test of the implosion bomb was considered essential by the director and most of the group and division 

leaders of the Laboratory. The first preparations for a test were made in March 1944, when Group X-2 

was formed in the Explosives Division headed by George Kistiakowsky. The duties of the X-2 group 

under Kenneth Bainbridge included making preparations for a field test in which blast, earth shock, 

 

i

Implosion-assembled weapons were designed on the principle of compressing the fissile material to super-criticality by 

detonation of a high-explosive implosion system.

ii “The July 16, 1945 Trinity Bomb Test,” September 1945. LANL Archives Collection A-1984-019.
10-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

neutron, and gamma radiations would be studied and complete photographic records would be made of 

the explosion and any atmospheric phenomena associated with it. This work was initially set up under 

Section X-2C, with L. Fussell Jr. in charge. 

In May 1945, a temporary organization was formed consisting of seven groups designated TR-1 through 

TR-7 (TR for Trinity). Organizationally, the test was called Project TR, and for reasons of secrecy the 

test site was referred to as T Site prior to the test. Personnel from R, G, O, F, and X Divisions and 

military men from the SED (Special Engineering Detachment) were reassigned to this “division” until the 

test was completed (Bainbridge 1976). Project Trinity was led by K. T. Bainbridge, with Frank 

Oppenheimer (brother of J. Robert Oppenheimer) serving as his Aide. Responsibilities of the TR groups 

were as follows: 

• TR-1, headed by John H. Williams: 

construction, procurement, transportation, timing, communications 

• TR-2, headed by J. H. Manley: 

measurements of air blast and earth shock 

• TR-3, headed by R. R. Wilson: 

physics measurements: prompt alpha, delayed neutron and gamma radiation 

• TR-4, headed by J. M. Hubbard: 

meteorology 

• TR-5, headed by J. E. Mack: 

spectrographic and photographic measurements 

• TR-6, headed by B. Waldman: 

air blast airborne measurements 

• TR-7, headed by L. H. Hempelmann: 

medical, including instruments, the monitoring group, and first aid 

• Special Assignments: 

four searchlight crews, an announcer, and weather advisers 

J. Robert Oppenheimer and George Kistiakowsky stated in a 1944 memo that “if we do not have accurate 

test data from Trinity, the planning of the use of the gadget over the enemy territory will have to be done 

substantially blindly” (Jones 1985). 

Site Selection and Construction 

Bainbridge’s group considered eight sitesi

 for testing the first implosion weapon— three in New Mexico, 

two in California, one in Texas, and one in Colorado. The Los Alamos scientists established the 

following criteria for the site: 

 

i

 Besides the Jornada del Muerto, the other sites in New Mexico were the Tularosa Basin near Alamogordo, the lava beds (now 

the El Malpais National Monument) south of Grants, and an area southwest of Cuba and north of Thoreau. Possible sites outside 

New Mexico were: an Army training area north of Blythe, California, in the Mojave Desert; San Nicolas Island (one of the 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-3

• flat terrain to minimize effects of the blast and to facilitate easy construction of roads and 

communication lines; 

• sufficient distance from populated areas but close to Los Alamos to minimize travel between the 

two sites; 

• clear and sunny weather on average to permit the extensive collection of optical data; 

• and convenience to good rail transportation. 

The Manhattan Project’s military head, Major General Leslie R. Groves, added conditions that the area be 

about 17 by 24 mi in size and that it have no Indians on it, the latter being so that he would not have to 

deal with Secretary of the Interior Harold Ickes, whom he thought would cause difficulties (Groves 1962). 

The final site selection was made in late August 1944 by Groves. When Groves discovered that in order 

to use a California location he favored he would need the permission of its commander, General George 

Patton, Groves quickly decided on the second choice, the Jornada del Muertoi

. This was because General 

Groves did not want anything to do with the flamboyant Patton, who Groves had once described as "the 

most disagreeable man I had ever met" (Szasz 1984). 

Bainbridge, a Harvard physicist assigned by J. Robert Oppenheimer to oversee preparations for the bomb 

test and base camp, chose the 18- by 24-mi tract of land in the northwest corner of the Jornada del 

Muerto (Journey of Death) valley east of the Rio Grande in the New Mexico desert (Bainbridge 1976, 

Jones 1985). As soon as the Air Force’s commanding general for the New Mexico district approved 

Bainbridge’s request to have a section of the Alamogordo Bombing and Gunnery Range turned over to 

the Manhattan Project, Bainbridge called Oppenheimer to tell him the good news and urged that they pick 

a code name for the site as soon as possible. Oppenheimer was familiar with a book of John Donne’s 

poems, and the opening line of the one he recalled was “Batter my heart, three-person’d God; for, you as 

yet but knock, breathe, shine, and seek to mend...” One theory is that Oppenheimer said “we’ll call it 

Trinity” based on that poem (Lamont 1965). 

Another theory is that Oppenheimer selected the name with reference to the divine Hindu trinity of 

Brahma (the Creator), Vishnu (the Preserver), and Shiva (the Destroyer). Oppenheimer had an avid 

interest in Sanskrit literature (which he had taught himself to read), and following the Trinity test is 

reported to have recited a passage from the Bhagavad-Gita (Radiochemistry Society 2007). 

A great deal of time was initially wasted in land surveys due to inadequate maps. Maps were requested 

through the Security Office in June 1944 but many were never received. The maps that were eventually 

 Channel Islands) off the coast of Southern California; on Padre Island south of Corpus Christi, Texas, in the Gulf of Mexico; and 

in the San Luis Valley of south central Colorado, near today's Great Sand Dunes National Monument (USDOE 1994). 

i

 This area was a short cut on the Camino Real, the King’s Highway that linked Mexico to Santa Fe, used to avoid a valley that 

was too narrow for supply wagons. Sixty miles of desert, with very little water and numerous hostile Apaches, led the Spanish 

conquerors of New Mexico to assign the name. 
10-4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

used were obtained by ordering all the geodetic survey maps and most of the grazing service and county 

maps for the state of New Mexico; aerial mosaics and land status maps had to be “scrounged”. Aerial 

photographs of the northwest corner of the Alamogordo Air Base were obtained from the Air Force and 

assembled into a photo mosaic that was used with a transparent overlay to determine locations for the 

main instrument shelters that would not be in washes. The selected land tract permitted separation from 

nearest habitation by a minimum of 12 mi to the north and west. Moreover, the government controlled 

the land out to 18 miles on the east. The nearest towns in any direction were 27-30 miles away and the 

prevalent winds were from the west (Bainbridge 1976). A memorandum providing justification for the 

construction and equipment requirements for the proposed scientific measurements was given to 

Oppenheimer in October 1944. A construction company contracted by the Army [J. D. Leftwich 

Company of El Paso, TX] completed the first facilities at the camp by the end of December 1944, and a 

small Military Police detachment under Lt. Bush arrived from Los Alamos to provide security for the site 

(Bainbridge 1976). Shortly after, a much larger group of scientists, technicians, medics, civil service 

personnel, and construction workers arrived. 

There was a maze of roads to be built, hundreds of miles of wire to be strung over and under the ground, a 

complete communication system to be installed, buildings to be erected, supplies, equipment, and 

personnel to be transported between Los Alamos and Trinity, all under the cloak of extreme secrecy 

(LASL 1979). By early 1945, there were more than 200 residents at the Trinity Base Camp. Civilian 

construction crews aided by construction personnel from Los Alamos built additional facilities in the 

spring of 1945 to ready the site for the bomb test, which was scheduled for early summer (Jones 1985). 

As depicted in Fig. 10-1 through Fig. 10-3, facilities at the test site included: 

• A Shot Tower (located at “Ground Zero,” the central reference point) 

• Base Camp (located 10 miles to the south-southwest) 

• South Shelter (located 10,000 yd (about 6 mi) to the south; housed VIPs and the control center for 

the test) 

• North Shelter (located 10,000 yd to the north; housed personnel, instruments, and searchlight crews) 

• West Shelter (located 10,000 yd to the west; housed personnel, cameras, and searchlight crews) 

The three shelters, which were heavily-built wooden bunkers reinforced with concrete and covered with 

earth, were code named Able, Baker, and Pittsburgh (National Atomic Museum 2007). Test personnel 

made use of the McDonald Ranch House for final assembly of the bomb’s plutonium core. Trinity Base 

Camp included stables, a blacksmith shop, water storage tanks, a hay barn, officers’ quarters, a supply 

room, mess hall, barracks, latrine, P.X. and day room, coal storage, infirmary, laboratory, technical 

warehouse, office, garage, gasoline storage tanks, fire station, engineering office, plumbing shop, 

electrical shop, carpentry shop, and drinking water tanks (Merlan 2001). 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-5

Fig. 10-1. Map of facilities at the Trinity Test Site (based on Lamont 1965)

The 100-Ton Test 

In the summer of 1944, a “100-ton test shot” using conventional high explosives (HE) was proposed to 

calibrate the blast and earth shock measuring equipment at the Trinity site and to serve as a dress 

rehearsal for the summer 1945 test. The “first” Trinity test occurred on May 7, 1945 at the New Mexico 

site 800 yd south of what would be ground zero for the July 16 test. It was the first chance to test 

experimental data under explosion conditions. Since explosions of more than a few tons of TNT have 

different characteristics than lesser amounts, 108 tons of HE (Composition B, a mixture of TNT and the 

explosive RDX) brought in from Fort Wingatei

 and a small volume of radioactive solution (to simulate 

the radioactive products of the nuclear test) were detonated atop a 20-foot platform (Fig. 10-4) so that 

dispersion could be characterized and instruments could be calibrated (LASL 1979, Jones 1985, 

Radiochemistry Society 2007). 

 

i

 Erickson (1946) described the explosive charge for the 100-Ton Test as 3590 wooden boxes (179,500 lbs) of flaked TNT and 

744 boxes (32,044 lbs) of pelletized Composition B. 
10-6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

Fig. 10-2. Location of the Trinity Test Site and Nearby Towns (from Jones 1985)
San Antonio

PEDRO

ARMENDARIS

GRANT

NO 34

C H U P A D E R A

M O U N T A I N S

Nogal Canyon

Rio

Grande

PEDRO

ARMENDARIS

GRANT

NO 33

San Andres Mountains

TELEPHONE LINE

TELEPHONE LINE

TELEPHONE LINE

TELEPHONE LINE

Naulda

C I B O L A N AT I O N A L F O R E S T

L

NATIO

AQUEDUCT

AQUEDUCT

NEW MEXICO

PRINCIAPL MERIDIAN

SOCORRO CO.

LINCOLN CO.

SOCORRO CO.

LINCOLN CO.

Vatican Road (West Rd)

Broadway

North Shelter Road

Pennsylvania Ave.

McDonald Ranch Road

Government Road

5 mi

5 km

10,000 ft

S I E R R A

T H E

M A L P A I S

C H U P A D E R A M E S A

O S C U R A 

M O U N T A I N S

Fite tank

Fite Well 

Coane

San Pedro

San Antonito

Laborcita

Escondida

Florida

Lemitar

Bosquecito

San

Marcial

Tiffany

Hard

Luck

Crossing

Kinney Wells

Tokay

Estes City

Ruins

Lovelace

Robsart

Polly

Coyote

Gallegos

Well

Chupadera Spring

Miera Tank

Padilla

Well

Vigil Bros.

Well

Oil

tank

North Well 

Shorty Tank

Olquin Well 

North Well 

Harriet Well 

Water Tank

Lambing Lake

Lambing Lake

Crater Well

Hackberry Well

Santa Fe Well

Antelope Well

Lambing Tank

Harriet Well 

Araya Well

Red

Tank

Gonzales Well

Tomas Silva Well

Apodaca Well

Field Well

Widen Well

Green Well

Hunter

Long

Well

Romero Well

Miera

Well

Gonzales Well

Jones Tank

Prarie

Spring

San Antonio Well

Fernandez

Tank

Max Well

Bruton Well

Bruton Tank

Bruton Well

Baber Well

Green Tank

Greens

Baber Well

Foster

Well

Story Well

Lewis Tank

Sec 21 Well

Hard Luck Well

Tank

Tank

Cain Well

Blakemore Well

Granjean Well

Bole Russell Tank

Chamise Well

Little Well

White Well Sanchez Well

West Well

Morten Well

South Well

Foster Tank

Torres Well

Rysinger

Well

Adobe

Well

Hale

Well

Larrimore

Tank

Moon

Tank

Hefner Tank

Ozane Well

Cooper Tanks

Bruton Tank

Brush Tank

Baca Tank

Smith Tank

Cornet Tank

Smith Well

South Well

Rabbit Spring

Burrego

Spring

Council Spring

Deep

Spring

Little Hefner Tank

Griffin

Tank

Rock Tank

Julian Tanks

Bulldog Tank

Sullivan Well

Bence Tank

Pinto Tank

Washboard

Tank

East Well

Rock Tank Well

Dean

Well

Pino Well

Jinks Well

Torres Tank

McDougal

Tank

O’Neal Tank

G Lucero

Tank

G Lucero Well

Morten Tank

Glover

Well Glover Tank

Little Red Tank

Story Tank

Story East

Tank

Selso Martinez Tank

Mesa Tank

Withers Tank Yates Tank

Gwinn Tank

Rabers Tank

Smith Tank

Murry Tank

Aquago Tank

Helm Tank

DillardWhitmore

Well

Yates Spring

Hog Sup Spring

Dripping

Spring

Oak Spring

Del Cuerto Spring

Palomas

Moonshine

Spring

Cottonwood

Spring

Kidd & Duffy

Spring

Hoffman Spring

Woods Tank

McDonald Tank

Red Tank (Dry) Mountain Tanks

Mockingbird Gap Well

McDonald Well

Scholle Well

Old Mills Well

Keller Spring

Nabors Tank

Moya Spring Trail

Canyon

Well

Red Tank Well

Red Tank

Forest Well Tank

Forest Well

Powder

River

Tank

Berry Tank

Frog Tank

Antelope Tank

Line Tank

Corona Tank

Gyp Tank

Long

Waterhole

Lake Tank

Malpais Tank

Hobbs Tank

Lemons Tank

Black Montain Tank

Shorty Tank

School Section Tank

Marcos

Tank

Roman Tank

Ortiz Tank

Highway Tank

Big Antelope Tank

Crater Tank

Little Antelope Tank

New Well

Monk Well

Taylor Tank

Taylor Well

North Well

South

Tank

Big

Tank

Cooper Tank Mesa Tank

New Mesa Tank

Lake Tank

Mesa Wells

School Section Well

School Section Tank

Script Tank

Lobo Tank

Hill Well

Nolda

Tank

No. 1

Butler Tank

Stevens Tank

Double

Tank

White

Tank

Stark

Tank

Pop Jackson Tank

Craven

Tank

AAA Tank Dillard Tan999k

J G Tank Rentfro Tank No. 2

Jaun Farmer Tank

Panther Tank Butler Tank

Sand Tank

Sandy

Tank

Rentfro Jr Tank

Rentfro Well

Murray Well

Sixshooter Quail Tank

Tank

M S Crockett Tank

Craven

Well

Pipe Line Well

Branum

Well

George McDonald

Well

Rim Rook Well

Clark Well

AAA Tank

Newmill Well

J S Dillard Tank

Sam Dillard Tank

Dalton Spring

Root

Spring

Bull Gap Tank

Twin Tanks Highway Tank

Bull Gap Spring

Cattle Guard Well

Willow spring

Walker Tank

W H Shrum Tank

School Section Tank

Little Red Tank

R C Withers Tanks

Brown Tank

Frenchman Tank

Red Canyon

Spring

Anchor Spring

Scott Spring

Coyote Spring

Bush Spring

Shady Spring

Fite Ranch

Fite

Ranch

Bruton Ranch

Bursom

Ranch

McDonald Ranch

Hdqtrs

Coker Hdqtrs

Sedillo

Lucero

Ranch

Dean Ranch

McDonald

Ranch (abandoned)

Ratliff Ranch

Nolda Ranch

Bursum

L A V A

Carrizozo

POP. 1546

BOSQUE DEL APACHE

NATIONAL WILDLIFE REFUGE J O R N A D A D E L M U E R T O 

North

Oscuro

Cedar Pass

Bat

Caves

Crater

Black

Mesa

LAVA

Little San

Pasqual Mtn

San

Marcial

Lake

Campana

Hill

Sand

Mtn

Mockingbird

Gap

Little Burro

Pk

Oscuro

Pk

South

Oscuro

Pk

Millers-Watch

Atom

Bug Pk

Broken

Back

Crater

Hughes

Hill

Cub

Mtn

Chaves

Mtn

Willow

Hill

LAVA

LAVA

Little Black

Peak

Red

Lake

TRINITY

SITE

Guard

Post 1

Guard

Post 6

Chamber

No. 3 Chamber No. 2

Chamber No. 1

GROUND ZERO

Guard

Post 5

Guard Post 3

Guard Post 7

Guard

Post 2

Guard

Post 4

South

Shelter

West

Shelter

North Shelter

(South Rd)

20 miles

10 miles

161

146

146

Searchlight

Station L-8

“HOT CANYON”

Claunch

41

Ojo de la Parida

Hightower

Harvey

Hooker

Mesa

Gaines

Hill

Sloan

Monte Prieto

Maxwell

41

30 miles

10

41

AIR

STRIP

Mesa Camp

Harriet

Ranch

Hdqtrs

RED BUTTE INST.

CRATER N. BASE

Baca House

Duncan

Farms

Ray Hunter

Ranch 

Nogal Ranch 

Padilla Ranch 

Station

Elmendorf Siding

Refuge

Hdqtrs

Jacobo

Sedillo

Ranch

Gilmore

Coal Mine

Hart

Coal Mine

Fernandez

Ranch

Padilla Ranch

Muncy

Ranch

Hills Home

Ranch

Williams Ranch

Gallegos

 Ranch

Romero

Ranch

Padilla

Ranch

Nep Chavez

Ranch

Chavez Ranch

Jones Ranch

Hdqtrs

Muncy

Ranch Hdqtrs

Green Ranch

Story

Ranch

Foster

Ranch

Hdqtrs

Arrieta

Ranch

Williams Ranch

Hdqtrs Wyre Hdqtrs

(Karo)

Romero

Ranch

Pearson

Ranch

F Thurman Ranch

Hansenburg Ranch

Withers

Ranch

A D Helm Ranch

H B Helm Ranch

Harvey Ranch

Hdqtrs

Kiloore Ranch

Gallagher Ranch

Oscura

Coal Mine

Barnes Ranch

Sprole Ranch

Chihuahua

Ranch

Withers

Ranch

Oscura

Range

Camp

Airport

Dunning

I-Bar-X

Cornett

Nickeles

Walker

Harkey

Gallacher

Shaeffer

Richard

Bond

Knight

Stral

Harkey 

TOPEKA

AND

SANTA FE

SOUTHERN PACIFIC

SOUTHERN PACIFIC

ATCHISON

W H I T E S A N D S P R O V I N G G R O U N D

A L A M O G O R D O B O M B I N G R A N G E

Socorro

Pk

7243’

Valverde

Pope

Siding

Carthage

Carthage P.O.

Bingham

Adobe

Hansonburg

Mining District White Store

Bingham

P.O.

T4S

T3S

T2S

T5S

T7S

T6S

T9S

 T8S

R1E R2E R3E R4E R5E R6E R9E R7E R8 E R10E 

Socorro

POP. 4334

“Red and Gray Hills”

“ R e d a n d G r a y H i l l s ”

52

85

85

1 10

380

380

54

54

10

10

10

60 Image generated by R. E. Kelley, LANL GISLab from data 

obtained at U.S.Geological Survey Seamless Data Distribution

website: http://gisdata.usgs.net/website/seamless/viewer.php.

National Elevation Data shaded relief (1/9 arc second resolution).

Map produced by cARTography by Andrea Kron 4/26/07

Shonka Research Associates, Inc.Figure 2: 

 Figure 10-3: Trinity Test Reference Map 10

10

10

10

106°45’

106°30’

106°15’

106°00’

34°00’

33°45’

33°30’

National Forest

Wildlife refuge

US military reservation

County boundary

Township and Range

Land grant

Hard surface, heavy-duty road

Hard surface, medium-duty road

Improved light-duty road

Unimproved, dirt road

Railroad

Telephone line

Aqueduct

Vegetated area

Lava

Building, occupied

Building, unoccupied

Mine

Cattle tank

Water tank

Well

Spring

Water body

Peak

Benchmark
10-8 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-9

Box after wooden box of HE were stacked until approximately 100 tons were in the pile. An irradiated 

uranium fuel slug from a Hanford reactor was dissolved using the apparatus shown in Fig. 10-5 and 

poured into flexible tubing threaded through the high explosive (Sugarman 1945). The solution 

introduced into the pile had beta activity of 1,000 Ci and gamma activity of 400 Ci. 

Fig. 10-4. Boxes of High Explosives Stacked for the "100-Ton Test"

Fig. 10-5. Diagram of the equipment used to dissolve an irradiated uranium fuel slug from a Hanford 

reactor for dispersion in the 100-Ton Test at Trinity Site (Sugarman 1945). The fuel slug entered the 

dissolver via the pipe from the left, by which off-gases were also exhausted. The radioactive solution 

exited via the tubing to the right, into the stack of boxed high explosives. 
10-10 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

The blast (Fig. 10-6) compressed and blew the surrounding earth into a saucer-shaped crater, expelling 

about 40% of the dirt. A scaling up the RaLa shots suggested that 10% of the activity would remain in 

the soil within a 300-ft radius. However, only 2% of the activity of the dissolved radioactive material was 

deposited in the crater out to a distance of 450 ft from the center. This indicated that simple scaling didn’t 

account for the increase in updraft with increased explosive charge. 

According to Richard C. Tolman, a physicist who has an advisor to General Leslie Groves, the explosion 

of the “100-ton test” aroused little comment in neighboring towns, but the illumination and sound were 

detected at the Alamogordo Air Base 60 mi away by a pre-warned observer. According to Hempelmann, 

the level of activity in the crater was low enough to be safe for several hours of exposure. The dissolving 

unit was covered with dirt and surrounded by a guard fence. Suggestions for improvement in facilities and 

procedure included paved roads to protect personnel and instruments from dust, more vehicles, more 

vehicle repairmen, and more telephone lines (Bainbridge 1976, Hoddeson et al. 1993). 

Fig. 10-6. Views of the “100-Ton Test” Blast at 1, 2, and 3 seconds after detonation. 

(photos obtained at nuclearweaponarchive.org/Usa/Tests/Trinity.html) 

Date Selection and Meteorology 

July 4 was the original target date for the second test at Trinity, the nuclear test. In mid- June, 

Oppenheimer said that July 13 was the earliest possible date for the test, however, the laboratory’s 

“Cowpuncher Committee” had primary responsibility for coordination and scheduling for Trinity. The 

committee was composed of S. K. Allison, former Director of the Metallurgical Laboratory, 

Kistiakowsky, Captain Parsons, C. C. Lauritsen, Bacher, and Hartley Rowe, a former Technical Advisor 

to General Eisenhower. It was organized “to ride herd” on the implosion program. 

After a review of developments on June 30, the Committee advanced the test date to July 16 to permit 

inclusion of certain additional vital experiments. The committee held its first meeting in early March 

1945. This group met often and published a semimonthly report called “The Los Alamos Implosion 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-11

Program” that presented in detail the current status of the work. Since Secretary of War Henry Stimson 

would be attending the Potsdam Conference starting on July 16, a test date of July 14 was requested by 

Groves so the results of the test would be known. The bomb test team, however, insisted on a test date of 

July 17. On July 7, Oppenheimer told Groves the test could take place on the 16th, but no earlier, since all 

parts of the Gadget (code name for the Fat Man implosion bomb) would not be ready before July 16 

(Jones 1985). 

The date of the Trinity test depended on the availability of components and on the weather. Haze, dust, 

and mirage effects would interfere with photographic measurements. Overcast skies would make flying 

more difficult for the airplanes to drop instruments. Winds had to be favorable to keep the radioactive 

cloud away from inhabited areas to the east and north. Each group was asked to specify the best weather 

conditions for their experiment, and meteorologist Jack Hubbard tried to find a date to match their 

requirements. Hubbard initially projected that the best dates for the Trinity test would be between July 18 

and 21, with July 12 through 14 as second best. The preferred time was several hours before dawn 

(Hoddeson et al. 1993). 

Meeting the weather needs of all groups proved impossible, and the groups had to compromise. Optimum 

winds would draw the radioactive cloud away from the nearby towns and break it up rapidly. Winds from 

the northwest through southwest were judged best and were typically the driest, therefore keeping 

thunderstorms from washing additional radioactivity down to the earth’s surface. No one was sure how 

high the radioactive cloud would go. An inversion layer over nearby towns, which were 27-30 miles 

away, would prevent material from touching down in those areas. Although thunderstorms were expected 

for July 16, Hubbard agreed that the shot could be made, even if conditions would not be optimal for all 

the planned experiments (Hoddeson et al. 1993). 

Scheduling Impacts on Planning of Protective Actions 

After the date for the Trinity test was set at 16 July 1945, Dr. Louis Hempelmann recalled that “there was 

feverish activity on our part to make the town monitoring program flexible enough to adapt itself to 

whatever wind conditions prevailed when the test was ready” (Hacker 1987). In anticipation that the 

people living in towns and on ranches in the immediate vicinity might have to be evacuated to avoid 

radioactive fallout, army intelligence agents led by Maj. T. O. Palmer searched the countryside trying to 

locate, list, and map every person living within a 40-mi radius of ground zero in case evacuation became 

necessary (Hoffman 1947, Bainbridge 1976, Hacker 1987). The Army stationed a detachment of 160 

enlisted men with vehicles at Socorro and other strategic points along main highways a few miles north of 

the site. The Army also detailed 25 Counterintelligence Corps (CIC) members to towns and cities up to 
10-12 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

100 mi from the site with instructions to summon evacuation troops if they were needed, and to help 

manage public reaction to the blast (Jones 1985). 

Instrumentation, Experiments, and Cameras Put into Place 

At a conference in Oppenheimer’s office on December 23, 1944, diagnostic experiments for the Trinity 

test were categorized as essential, desirable, or unnecessary. Essential experiments include the pressure of 

the blast wave and the time spread in the firing of the detonators. Desirable experiments included 

photographic and spectrographic analyses of the fireball, and measurement of the earth’s motion during 

the explosion in case any lawsuits were brought against the laboratory for blast damage. All other 

experiments were deemed unnecessary (Hoddeson et al. 1993). 

Much emphasis was placed on measuring the energy in the blast wave. This was achieved by using a pair 

of beryllium-copper diaphragm microphones to record the peak pressure following the explosion because 

it was suggested that the change in pressure generated by the blast wave was the only quantity that could 

be measured accurately from 20 miles away during combat use. A more sophisticated method was also 

used, which consisted of making a precise measurement of the velocity of sound at the site of explosion 

and comparing it to the velocity of the blast wave. Spring-loaded piston gauges, water-filled pistons, 

diaphragm box gauges, and ball and cylinder gauges were calibrated to record a range of peak pressures 

from the blast. The mechanical gauges were insensitive to electrical disturbances and acted as backup to 

the electrical methods (Hoddeson et al. 1993). 

Plans were made to estimate the energy of the bomb in several ways, including determination of the 

number of fissions by measuring the number and intensity of the gamma rays emitted. Prompt and 

delayed gamma rays could be measured separately. Ionization chambers were used to measure the 

prompt gamma rays. The ionization from the delayed gamma rays was measured by “suitable devices” 

placed within 10 or 20 miles of the gadget. The number and energy of the gamma rays could be used to 

derive the number of fissions and calculate the efficiency and yield of the bomb (Hoddeson et al. 1993). 

The energies and distribution of neutrons from the blast provided another method for calculating yield, 

but they were difficult to measure since they were more likely to be degraded or absorbed. Plans were 

made to measure time-integrated neutron flux using gold foils in protective tubes placed between 300 and 

1000 meters from ground zero that would be activated by slow neutrons from the blast. Arrangements 

were also made to perform direct examinations of the soil from the area near the blast for plutonium and 

fission products to support estimation of the efficiency of the explosion. Two lead-lined tanks (Fig. 10-7) 

with trap doors on their undersides were equipped to recover soil samples from the Trinity site crater 

(Hoddeson et al. 1993). 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-13

Another essential measurement was the time interval between the detonation of high explosives and the 

beginning of the chain reaction to determine if the nuclear reaction was started by the initiator or began 

prematurely. The degree of simultaneity of the detonators required for an efficient implosion was 

unknown at the time. The presence of an informer switch at each detonator superseded the requirement 

for the test to be an exact duplicate of the gadget as it would be used in combat (Hoddeson et al. 1993). 

A variety of instruments were put into place to measure earth motion, including the change in position of 

stakes, geophones, and seismographs. Seismograph measurements were made on site at the North Shelter 

(10,000 yards from ground zero) and at Base Camp and off site at Tularosa, Carrizozo, and San Antonio 

(Hoddeson et al. 1993). 

Fig. 10-7. One of two lead-lined tanks prepared to recover soil samples from near ground zero 

The primary purpose of the photography effort was to have a good photographic record for spectrographic 

and yield analysis. Different stages of the explosion required different film speeds, lenses and exposures, 

and no one knew the amount or kind of light that would be emitted during the explosion. Fastax cameras 

taking 10,000 frames per second were put into place to record minute details of the beginning of the 

explosion. Fastax cameras placed 800 yd from the blast were protected by a steel and glass bunker and 

were mounted on a sled that could be pulled out of the contaminated area by a chain attached to one of the 

lead-lined tanks. They would exhaust their film supplies in several hundredths of a second. Rotating-drum 

spectrograph cameras were positioned to monitor light wavelengths emitted by the fire ball, and pinhole 

cameras were put into place to recorded gamma rays. The only available well-exposed color photograph 

of the explosion was taken by Jack Aeby, a 21-year old Los Alamos scientist and amateur photographer 

(Hoddeson et al. 1993) using his own camera, which Italian physicist Emilio Segre had secured 

permission for him to carry on site to record the activities of Segre’s group as they studied delayed 

gamma rays (Savage and Storm 1965). 
10-14 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

The “Jumbo” Containment Vessel

The construction of a large pressure vessel to contain the rare and valuable plutonium if the first atomic 

bomb was a dud was considered in the winter and spring of 1944. Other recovery methods considered 

included a below-ground sand cone (sand to high explosive weight ratio 15,000:1) and a cylindrical tank 

of water (water to high explosive weight ratio 50:1 or 100:1). Although a container could possibly allow 

scientists to recover the plutonium, all proposed blast, earth shock, and optical measurements would be 

rendered useless by the presence of the vessel, so this idea was not popular with the scientists. The final 

design for Jumbo was a 25 ft by 12 ft cylinder with hemispherical ends that weighed 214 tons. It was 

built by Babcock and Wilcox Corporation in Barberton, Ohio and shipped in early April 1945 on a 

specially fabricated railcar to a railroad siding at Pope, New Mexico (Fig. 10-8). A 64-wheeled trailer 

pulled by two tractors was used to move the vessel the 25 miles from Pope to the test site (Jones 1985). 

By March 1945, all recovery methods were abandoned because sufficient plutonium for a second test 

would be available from Hanford, and Jumbo was never used. However, it was erected 800 yards from 

ground zero in case it was needed for a second test (Hoddeson et al. 1993). 

Fig. 10-8. The "Jumbo" containment vessel being loaded on a specially made, 64-wheel trailer at the 

Pope, NM railroad siding (left) and making its 25-mi trip to the Trinity site on a road constructed for that 

purpose (right). 

. 

Final Preparations 

Two complete sets of high explosive castings were available on July 10. Prior to July 7, there had not 

been enough lens castings to make a complete charge. Kistiakowsky and Bradbury picked the best 

looking pieces for the Trinity assembly and designated the rest for the full-scale magnetic Creutz test of 

the gadget to be conducted at Pajarito Canyon without active material. The Trinity charge was assembled 

on July 12 at V Site in Los Alamos and started on its journey to the Trinity site at midnight, arriving just 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-15

before noon on the 13th (Bainbridge 1976). Kistiakowsky wrote that he chose to leave just after midnight 

on Friday the 13th because he “believed in unorthodox luck” (Kistiakowsky 1980). 

On July 12, two scientists arrived from Los Alamos in an army sedan with the 239Pu core for the 

implosion device. An interview with Phillip Morrison revealed that he rode down to Trinity with the 

weapon core. He and Marshall Holloway, both G Division engineers, were designated as the Pit 

Assembly team in April 1945 and were responsible for placing the core into the gadget during final 

assembly. Morrison didn’t remember a great deal about the ride to the Trinity site, but did recall that he 

was “rather afraid of the fast driving young woman who drove us down there with the convoy, who was 

really a high-speed... pedal to the floor all the way. That driver was the scariest thing” (Morrison 1999). 

General Farrell signed a receipt for the active material, formally completing the transfer from the 

scientists to the Army (Jones 1985). All components were in place except the detonating system at 5:45 

pm on July 13. The device was hoisted to a metal shed on a platform atop a 100-ft steel shot tower, a 

surplus Forest Service fire-watch tower (Fig. 10-9 and Fig. 10-10) (National Atomic Museum 2007). 

Fig. 10-9. The steel shot tower used for the Trinity test 
10-16 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

Fig. 10-10. The assembled "Gadget" sits in the metal shed atop the 100-ft metal test tower. To the right 

in this photo is Norris Bradbury, who would follow Oppenheimer as LASL Director

A truckload of mattresses were piled up under the Gadget in case it fell (Hoddeson et al. 1993). The 

detonator group completed the firing circuit and technicians added an apparatus for experiments. By 5:00 

pm on July 14, the device was ready for the test. 

Observers including Office of Scientific Research and Development (OSRD) Director Vannevar Bush 

and National Defense Research Committee Chairman James Conant arrived with General Groves on 

Sunday, July 15. The large contingent from Los Alamos arrived in three buses around 3:00 am on the 

morning of July 16, just before the scheduled test time of 4:00 am. The weather was rainy and there were 

occasional flashes of lightning. General Groves and Oppenheimer decided to delay the shot for an hour 

and a half. The rain stopped at 4:00 am. Shortly before 5:00 am, with the wind still blowing in the “right” 

direction, they gave the go-ahead signal for the test (Jones 1985). 

Health and monitoring organization preparations addressed issues of cloud and trail contamination. 

According to Hempelmann, the activity of the cloud would vary with the efficiency of the explosion and 

it would need to be monitored until it was dispersed since it was a potential hazard to the local population. 

If loose dust from the crater and the surrounding area rose to 10,000 feet and fell at a normal rate there 

might be danger to towns 30 miles away, due to a prediction of 7 R h-1 from fission products and the 239Pu 

tolerance dose being exceeded in 22 h. Hubbard assured all concerned that the meteorological conditions 

that could affect the cloud were predictable, including low humidity, temperature inversion, winds above 

the inversion, atmospheric lapse rate, and heating of the earth. Low humidity would exclude a 

thunderstorm created by the blast and heat effects that could cause precipitation of the active material 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-17

over a small area. The inversion layer would retard particles from falling until the morning thermals 

mixed the active material more thoroughly. A 30 mph wind to the SE above the inversion layer would 

carry the cloud beyond the nearby towns. A stable lapse rate would allow the fire ball to ascend until it 

reached a higher inversion at 20,000 ft and preclude heavy active particles from falling on a small area. 

The usual heating of the earth would break the inversion layer and move air in an ascending manner. 

Hubbard predicted that contaminated material thrown into the air could be suspended for weeks 

(Bainbridge 1976). 

A betting pool was started by Los Alamos scientists on what the yield of the Trinity device would be 

(National Atomic Museum 2007). Yields from zero to 45,000 tons of TNT (45 kilotons) were selected. 

Bainbridge was furious when he heard discussions of the possibility that the blast would be hot enough to 

ignite the nitrogen in the atmosphere and would annihilate the human race (Hacker 1987). This possible 

outcome had been suggested by Edward Teller, but fears were quashed by intensive studies by Hans 

Bethe and others that were documented by Teller and Emil Konopinski in December 1943. These studies 

concluded that the safety factor was “at least a factor of 60” (Rosen 2002). 

Bus loads of visitors from Los Alamos and elsewhere started arriving near the Trinity Site around 2:00 

a.m. on July 16. Many of them who had no duties for the test set up on Campaña Hilli

 (about 32 km to 

the northwest of ground zero) to watch the event. This included Ernest O. Lawrence, Hans Bethe, 

Edward Teller, Robert Serber, Edward McMillan, James Chadwick, and Richard Feynman (Merlan 

2001). 

At the time of the detonation, 99 project personnel (about 76 civilian and 23 military) were in the three 

shelters: 29 at North, 37 at West, and 33 at South. Harvard president James Conant, General Groves, and 

Vannevar Bush observed the test from a slit trench at Base Camp; J.R. Oppenheimer, Kenneth 

Bainbridge, George Kistiakowsky, Thomas Farrell, Donald Hornig, and Samuel Allison watched from the 

South 10,000 Shelter, which served as the control point (Maag and Rohrer 1982, Merlan 2001). Groves 

and Oppenheimer purposefully watched the test from different locations, separated by some distance, so 

that if one were killed, the other could likely continue to manage the project. 

The Trinity Test 

The Trinity “Gadget” was detonated on Monday, 16 July 1945 at 5:29 a.m. Mountain War Time at 

latitude 33°28’- 33°50’, longitude 106°22’- 106°41’, UTM coordinates 630266 on the Alamogordo 

Bombing Range, New Mexico. The time is not known with certainty, because scientists experienced 

difficulty in picking up station WWV for a time check (Bainbridge 1976, Maag and Rohrer 1982). 

 

i

 “Campaña” also appears as “Campania,” “Campagne,” or “Campagna” in various sources. These spellings might have been 

adopted to help those with little knowledge of the Spanish language pronounce the word. 
10-18 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

Observations/Descriptions 

The nuclear blast (Fig. 10-11) created a flash of light brighter than a dozen suns (National Atomic 

Museum 2007). The light was seen over the entire state of New Mexico and in parts of Arizona, Texas, 

and Mexico. The resultant mushroom cloud rose to over 38,000 ft within minutes, and the heat of the 

explosion was 10,000 times hotter than the surface of the sun. At 10 mi away, this heat was described as 

like standing directly in front of a roaring fireplace. Data from hundreds of instruments recorded what 

occurred that morning. The blast was more powerful than expected, however, and many instruments and 

experimental devices were ruined (Lamont 1965). A brilliant yellow light was seen as far away as 

Albuquerque and Los Alamos to the north, Silver City New Mexico to the west, and El Paso Texas to the 

south. A sensation of heat persisted as a huge ball of fire took shape and transformed into a moving 

orange and red column. Out of this spectrum rose a narrower column that rapidly spilled over to form a 

giant white mushroom cloud surrounded by a blue glow. As the glow began to fade, observers at the base 

camp felt the pressure of the shock wave and its rumble reverberated for more than five minutes in the 

surrounding hills (Jones 1985). General Thomas Farrell, Deputy to Gen. Leslie Groves, said that “The 

effects could well be called unprecedented, magnificent, beautiful, stupendous and terrifying. No manmade phenomenon of such tremendous power had ever occurred before.” “I am become Death, the 

Destroyer of Worlds” was reportedly said by J. Robert Oppenheimer. Dr. Kenneth Bainbridge, Director 

of Trinity Test, said “Now we are all sons-of-bitches.” 

Fig. 10-11. Two images from the only well-exposed color photograph available for the Trinity blast, 

taken by Los Alamos scientist and amateur photographer Jack Aeby from near Base Camp. As Aeby later 

said, “It was there so I shot it.” 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-19

The crew sent to Searchlight Station L-8 to illuminate and observe the cloud from the blast recorded that, 

at t + 15 minutes, the cloud was divided into three parts—a dense white mushroom cloud, a flat, fairly 

long red dust cloud, and a reddish-brown column that seemed to come from ground zero (Blair et al. 

1945b). The three-man crew was located 19.5 miles from ground zero, to the northeast, as shown in Fig. 

10-12. At t + 30 minutes, the high mushroom cloud had moved directly toward their position, and had 

“taken on the shape of the North American part of the western hemisphere” while the “lower red-brown 

cloud and column took on the shape of a question mark, while the brown dust seemed to be still 

emanating from position 0.” Radioactive material started to descend upon Searchlight Station L-8 

between t + 90 minutes and t + 120 minutes (Blair et al. 1945b). The radiation level peaked at its highest 

level at 8:25 a.m., and remained constant through 9:15 a.m., after which it started to decline (Blair et al. 

1945b). 

Physicist Otto Frisch had been taken to a spot about 32 km from ground zero (probably on Compaña 

Hill). Because he couldn’t find his assigned dark glasses as the countdown progressed in the dark that 

early morning, Frisch initially turned away from ground zero but later recorded the following 

observations (Frisch 1979): 

“And then, without a sound, the sun was shining; or so it looked. The sand hills on the edge of 

the desert were shimmering in a very bright light, almost colourless and shapeless. The light 

did not seem to change for a couple of seconds and then began to dim. I turned round, but that 

object on the horizon which looked like a small sun was still too bright to look at. I kept 

blinking and trying to take looks, and after another ten seconds or so it had grown and dimmed 

into something more like a huge oil fire, with a structure that made it look a bit like a 

strawberry. It was slowly rising into the sky from the ground, with which it remained connected 

by the lengthening grey stem of swirling dust; incongruously, I thought of a red-hot elephant 

standing balanced on its trunk. Then, as the cloud of hot gas cooled and became less red, one 

could see a blue glow surrounding it, a glow of ionized air; a huge replica of what Harry 

Daghlian ... [saw just over five weeks later at Omega Site in Los Alamos] when his assembly 

went critical and signaled his death sentence. The object, now clearly what has become so well 

known as the mushroom cloud, ceased to rise but a second mushroom started to grow from its 

top; the inner layers of the gas were kept hot by their radioactivity and. Being hotter than the 

rest, broke through the top and rose to even greater height. It was an awesome spectacle; 

anybody who has ever seen an atomic explosion will never forget it. And all in complete 

silence; the bang came minutes later, quite loud though I had plugged my ears, and followed by 

a long rumble like heavy traffic far away. I can still hear it.” 
10-20 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

Fig. 10-12. Map of areas to the northeast of the Trinity Site where highest off-site radiation levels 

were measured after the July 1945 shot.
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-21

Less than a half hour after the test shot, General Groves called his secretary in Washington, D.C. to 

pass on word of the test to Secretary Stimson. He reported that the strength of the explosion was at 

least “satisfactory plus and perhaps far greater than estimated” (Lamont 1965). 

Trajectory of the Cloud and Observations of Fallout 

Up to the time of the shot and for the first half hour after the shot, information about the direction of 

travel of the cloud was vague. A 20 mi h-1 wind was blowing from the southeast toward Guard Gate 2i

 to 

the northeast of ground zero. It was thought that the radioactive cloud would move in a line toward the 

northwest from ground zero, but the cloud did not travel in that direction (Hoffman 1947). 

Col. Stafford Warren, Chief of the Manhattan Project’s Medical Section, documented the following in a 

July 21, 1945 report to Gen. Groves (Warren 1945): 

“The energy developed in the test was several times greater than that expected by scientific 

group. The cloud column mass and top reached a phenomenal height, variously estimated as 

50,000 to 70,000 feet. It remained towering over the northeast corner of the site for several 

hours. This was sufficient time for the majority of the largest particles to fall out. Various 

levels were seen to move in different directions. In general the lower one-third drifted 

eastward, the middle portion to the West and northwest, while the upper third moved 

northeast. Many small sheets of dust moved independently at all levels and large sheets 

remained practically in situ. By zero plus 2 hours, the main masses were no longer 

identifiable except for the very high white mass presumably in the stratosphere. 

 By 0800 hours the monitors reported an area of high intensity in a canyon 20 miles 

northeast of zero. ... Intensities in the deserted canyon were high enough to cause serious 

physiological effects. 

 The distribution over the countryside was spotty and subject to local winds and contour. 

It skipped the nearby highway #380 (20 mi. N.E.) except for low intensities which were 

equaled at twice and three times the distance. It is presumed that the largest outfall occurred 

in the N.E. quadrant of the site. This can only be explored by horseback at a later date.” 

Between 6:00 and 7:00 am, the wind direction changed from southeasterly to southwesterlyii, and the 

cloud was traveling northeast at 15 mi h-1, at altitude 35,000 ft, and rising about 14,000 ft h-1. Monitors 

found readable gamma radiation 1.7 h after the shot 19 mi from ground zero. This indicated that the active 

 

i

 Guard Gates or Guard Posts were typically just tents or parked trucks along the roadside used to provide shelter for security 

guards that controlled access to the various areas of the Trinity Site. 

ii Although not adhered to in many historical reports, this summary follows the convention of describing wind directions as the 

directions that the wind is blowing from. 
10-22 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

dust falling from high altitudes had been caught by the northwesterly wind near the ground and blown in 

the direction of Socorro (Hoffman 1947). 

The cloud drifted northeastward at about 10 mi h-1, dropping its trail of fission products across a region 

measuring 100 mi long and 30 mi wide (Lamont 1965). In the deep ravines northeast of the Trinity site, 

where cattle grazed, the radioactivity settled in a white mist (Lamont 1965). The off-site monitors feared 

inversions and solar heating of air in the canyons, which could cause thermal updrafts that can lead to 

sudden wind shifts and carry airborne contamination beyond the expected limits, possibly dumping it in 

some remote area unknown to the monitors (Lamont 1965). 

William Wrye, whose house was 20 mi northeast of Trinity, tells that “for four or five days after that, a 

white substance like flour settled on everything” (Albuquerque Journal News 1995). And rancher M. C. 

Ratliff said that “the ground immediately after the shot appeared covered with light snow,” adding that for 

several days afterward, especially at dawn and dusk, “the ground and fence posts had the appearance . . . 

of being frosted” (Hacker 1987). 

As the cloud drifted beyond Carrizozo, with monitoring teams in full chase, scientists realized that the 

monitors had overreached the limits of their radio contact with base camp. As fallout was dropping on 

northern communities like Coyote, Ancho, and Tecolote, the monitors were unable to relay the results to 

Stafford Warren at Base Camp (Lamont 1965). Even as officials at base camp were advising Washington 

that the fallout danger was diminishing, the monitors were racing back toward Trinity with reports that 

fallout had reached a number of areas beyond their jurisdiction, such as Vaughn (Lamont 1965). 

The [visible] cloud from the Trinity blast appears to have dissipated over the vicinity of Vaughn, 96 mi 

from ground zero. It appears that the main cloud wrapped itself around Gallinas Peak, 65 mi north of the 

site, and broke up (Lamont 1965). There is evidence that fallout from the Trinity test traveled as far as 

Indiana. In the fall of 1945, the Kodak Company observed some spotting on their film and they traced it 

back to contamination in their cardboard. Dr. J.H. Webb, a Kodak employee, studied the matter and 

concluded that the 141Ce contamination must have come from a nuclear explosion somewhere in the U.S. 

In fact, it came from the Trinity Test (Webb 1949).i

 Fallout from the explosion had contaminated the 

river water that the paper mill in Indiana had used to manufacture the cardboard pulp. Recognizing the 

sensitivity of this information, Dr. Webb kept his discovery secret until 1949 (Webb 1949). Airplanes 

equipped with filters followed the Trinity cloud across Kansas, Iowa, Indiana, upstate New York, New 

England, and out to sea (Blair et al. 1945a). 

 

i

 Memorandum by Julius H. Webb, “Fogging of film by radioactive contaminants at Eastman Kodak Company,” 15 March 1949. 

In: LANL Archives Collection A-1999-019, Box 69, Folder 14. 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-23

Witnesses from Outside the Project 

Due to the intense secrecy surrounding the test, accurate information of what happened was not released 

to the public until after the second atomic bomb had been dropped on Japan three weeks later. Without 

being officially informed, many people in New Mexico were well aware that something extraordinary had 

happened the morning of July 16, 1945. The blinding flash of light, followed by the shock wave, had 

made a distinct impression on people who lived within a radius of 160 miles of ground zero. Windows 

were shattered 120 miles away in Silver City, and residents of Albuquerque saw the bright light of the 

explosion on the southern horizon and felt the tremor of the shock waves moments later (National Atomic 

Museum 2007). 

In spite of the “no fly” order, pilot John Ellison, a flight engineer, and four trainees took off from Roswell 

Air Field in a B-29 just before 5 am on July 16, 1945. They were on a training mission for the 9- to 12-h 

bombing missions planned over Japan, and had been cleared to fly to California. About 42 min into the 

flight, they were 18,000 ft over the northern part of the Sacramento Mountains bordering the White Sands 

Missile Range when they saw a searing light and the red fireball of the first atomic bomb test. Ellison 

estimated that he and his crew were 15-20 mi from ground zero and may have been the closest persons to 

witness the test from the air. This is likely to be true, as the two B-29 observation planes were unable to 

take off from Kirtland Field due to bad weather, including heavy clouds and thunder storms (Groves 

1945). Ellison radioed the tower in Roswell and they told him to get the plane back. Later he learned that 

authorities associated with the atomic test overheard his radio transmission and ordered the base to call in 

the planes (Santa Fe New Mexican 2005). 

The “Cover Story” 

An officer from General Grove’s headquarters gave the cover story to the commander of the Alamogordo 

Air Base to be issued as soon as the test had occurred. Another officer was stationed in the Associated 

Press office in Albuquerque to suppress any stories that might alarm the public. Groves also arranged 

with the Office of Censorship in Washington, D.C. to keep news of the explosion from getting into 

newspapers in other parts of the country. The Army issued an order grounding all commercial planes and 

suspending all flights from nearby military installations (Jones 1985). Groves modified the cover story to 

fit the exact circumstances of the test and gave permission to the Associated Press at Albuquerque to 

release it as follows: 

“Alamogordo, N.M., July 16. The commanding officer of the Alamogordo Air Base made the 

following statement today: Several inquiries have been received concerning a heavy explosion which 

occurred on the Alamogordo Air Base reservation this morning. A remotely located ammunition 

magazine containing a considerable amount of high explosives and pyrotechnics exploded. There 
10-24 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

was no loss of life or injury to anyone, and the property damage 

outside of the explosive magazine itself was negligible. Weather 

conditions affecting the content of the gas shells exploded by the 

blast may make it desirable for the Army to temporarily evacuate a 

few civilians from their homes” (Jones 1985). 

Fig. 10-13 shows an article that resulted from release of the cover story. 

Experimental Results 

Immediately after the test, Sherman M-4 tanks, painted white, equipped 

with their own air supplies, and lined with two inches of lead went out to 

explore the crater area. The lead added 12 tons to each tank's 

weight, but was considered necessary to protect the tanks’ occupants 

from the radiation levels at ground zero. The tank's passengers found that 

the 100-foot steel tower had virtually disappeared, with only the metal 

stumps of its legs imbedded in concrete remaining (USDOE 1994). 

The most important result was that the implosion device worked. The 

yield was three times larger than predicted. T-Division’s predictions 

were between 5 and 10 kilotons. Radiochemical analysis of the soil 

samples gave an estimated yield of 18,600 tons of TNT, quite close to 

the currently accepted value of 20 to 22 kilotons. Some of the observers 

tried to estimate the yield while watching the test. Enrico Fermi 

performed a fairly simple experiment, in which he tore a sheet of paper 

into pieces and dropped them as the blast wave passed his location. They 

moved about 2.5 ft, which Fermi calculated to be equivalent to 10,000 

tons of TNT. 

The Socorro Chieftain carried the following item after the Trinity Test, 

but before the true story of what had happened was released: 

“An explosives magazine at the Alamogordo air base blew up 

Monday morning [see ‘The Cover Story,’ below], and the flash, 

sound and shock were seen, heard and felt in Socorro, more than 100 

miles away . . . The flash was intensely white and seemed to fill the 

entire world. It was followed by a large crimson glow. The flash 

lasted only a second or so. It was so bright that Miss Georgia Green 

Fig. 10-13. An Associated 

Press article that resulted 

from the Trinity cover story
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-25

of Socorro, blind student at the University of New Mexico, being driven to Albuquerque by her 

brother-in-law, Lieutenant Joe Wills, asked, "What's that?" 

The blast measuring devices performed well, but the gamma ray measuring devices were overloaded. 

The higher gamma radiation fogged the motion picture films slightly and ruined the measurements of 

detonator simultaneity. Few neutron detectors survived the blast. Seven of the gold foils were recovered. 

No gauges with 200 ft of ground zero survived. The seismographs detected a tremor at the North Shelter 

and at San Antonio 28 mi away. The yield and size of the fire ball prompted scientists to specify the 

height of the Hiroshima and Nagasaki bombs at 1,850 ft (Hoddeson et al. 1993). According to 

Bainbridge, 1% of the fission products were left in the crater and its vicinity (Bainbridge 1976). Due to 

the presence of dust around ground zero “a large region of the countryside was contaminated by fission 

products.” This is discussed in more detail in a LASL report (Hirschfelder et al. 1945). 

Because of the storm conditions on the morning of the 16th, Oppenheimer asked Waldman and Alvarez 

not to fly over ground zero to drop the gauges that would radio data back to the B-29s because the flight 

would be too dangerous (Hoddeson et al. 1993). 

Local Conditions 

 

Fig. 10-14 shows an aerial photograph of the area around ground zero at 28 h after the test. The 

blackened area shows the radius of intense heat that burned off all the vegetation. The blast effect in this 

area and resulting updraft of hot gases removed a thin layer of soil and burned debris from the blast area. 

Fig. 10-14. Aerial view of the Trinity ground zero (center) at 28 h after the shot. The circle 

to the lower right is from the 100-Ton test, with its detonation point exactly 1 mi distant. 
10-26 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

Measurement and Management of Off-site Consequences 

While not much was said publicly about measurements of off-site fallout from the Trinity test for years 

after the shot, advance planning and preparation did take place before the test to establish the ability to 

measure off-site radioactivity and promote public safety to the extent allowed during war time, when 

many other objectives were competing. 

Competing Priorities for Secrecy, Security, Safety, and Avoidance of Litigation 

Writing 25 y after the Trinity test, General Groves described what had been six immediate military 

requirements for adequate Project Trinity security (Hacker 1987). While Groves’ recollections might 

have reflected 1970 as well as 1945 views, the list of requirements for security is informative: 

• Barring strangers from the test site; 

• Preventing harm to project members; 

• Reducing chances that outsiders could learn of the explosion; 

• Safeguarding the public from fallout; 

• Planning for emergency evacuation; and 

• Forestalling any national press reports that might alert Japan. 

Testing an atomic bomb on American soil, no matter how remote the site, clearly threatened the secret of 

the atomic bomb project— the most violent man-made explosion in history could hardly pass unseen. It 

was important that the Japanese not be alerted, and elaborate public safety precautions seemed likely only 

make the event more noticeable (Hacker 1987). But fortunately, it was thought, to some degree the same 

measures that kept Trinity safe from prying eyes could also help keep the public safe from the test and 

testers safe from lawsuits (Hacker 1987). 

When general Groves visited Los Alamos in April 1945 for a briefing on Trinity plans, his first questions 

were about legal matters (Hacker 1987). He was concerned about damage or harm from earth shock, air 

blast, and toxic effects, and felt that valid records would help secure the army against damage claims. 

This is why, for example, 20 government agents were stationed in towns up to 100 miles from ground 

zero on shot day, equipped with recording barographs, seismographs, and recording radiation meters to 

measure remote shock, blast, and radiation (Hoffman 1947, Bainbridge 1976, Hacker 1987). 

Until just weeks before the test, fallout simply appeared to be a minor problem. Los Alamos “plans to 

send out radio equipped cars provided with instruments for measuring alpha particle and gamma ray 

intensities in outlying areas” met Groves’ approval (Hacker 1987). “On the basis of these measurements, 

evacuation of inhabitants could be carried out if necessary.” Groves dismissed any thoughts of advance 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-27

warning to nearby ranchers and townsfolk, because “the danger seemed modest given the proper weather” 

(Hacker 1987). Keeping the secret forced some compromises with safety (Stannard 1988). 

Shortly before the field test, updated calculations provided indication that fallout could be more 

substantial and widespread than originally thought (Hacker 1987, Stannard 1988). While there was 

considerable discussion regarding whether assumptions on which those calculations were based were 

overly pessimistic, the fallout calculations completed shortly before June 23, 1945, provided predictions 

that were sobering, and establishment of monitoring and evacuation plans seemed more prudent (Hacker 

1987). 

Figure 10-15 shows the locations of ranches, farms, towns, camps, and towns within approximately 40 

miles of Trinity ground zero that are labeled on USGS 1:250,000 maps issued in 1954. 

General Groves and the Manhattan Project’s Medical Director, Stafford Warren, are said to have known 

that the Army was not eager to pursue too diligently the possibilities of widespread fallout (Lamont 

1965). The specter of endless lawsuits haunted the military, and most of the authorities simply wanted to 

put the whole test and its aftereffects out of sight and mind (Lamont 1965). 

Potential Pathways of Public Exposure 

Members of the public could have been exposed to radiation and radioactive materials from the Trinity 

event by a number of pathways, including: 

1. Direct, prompt radiation from the blast itself 

2. Direct, external irradiation from the cloud passing overhead or near by 

3. Direct, external irradiation from being immersed in the cloud 

4. Direct, external irradiation from contamination deposited on the ground 

5. Direct, external irradiation from contamination deposited on the skin, hair, or clothing 

6. Internal dose from inhalation of airborne contamination 

7. Internal dose from inhalation of resuspended fallout particles 

8. Internal dose from ingestion of contaminated food products 

Initial radiation from fission and other processes in the explosion ceased in less than a minute, as delayed 

neutrons lasted only seconds; radiation from the fireball, although substantial, decreased as the square of 

distance and was further attenuated by air. Ten thousand feet from ground zero, well within site 

boundaries, radiation was too low to detect (Hacker 1987). 

 
10-28 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

Fig. 10-15. Locations of ranches, farms, camps, and towns within about 40 mi of Trinity Site ground zero 

based on USGS 1:250,000 maps issued in 1954. Circles are at radii of 10, 20, and 30 mi.

Pathway 1 was apparently relatively insignificant to members of the public. Had it been significant, it 

would have shown up on the “remote sentinel robot ionization chambers” that spotted the main access 

roads at distances between 400 and 10,000 yd (Hoffman 1947, Hacker 1987) and the recording gamma 

meters that were stationed in local towns. 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-29

The post-shot radiological monitoring program conducted by Los Alamos scientists with the assistance of 

military personnel addressed, to the extent possible with the equipment available at the time, pathways 2, 

3, and 4 dealing with direct exposure from radioactivity in the cloud or deposited on the ground. This 

was accomplished by the collection of data by field monitoring crews, which were analyzed and reported 

in documents assembled by Hoffman and others. 

The post-shot radiological monitoring program, however, did not focus on assessment of pathways 5 

through 8. No monitoring for contamination on the bodies of members of the public was performed (such 

as frisking or collection of wipe or wash samples). This pathway was found to be important for livestock, 

because they stay mostly outdoors, do not wear clothes, and do not bathe. It was reported that cattle that 

grazed on Chupadera mesa suffered local beta burns and temporary loss of dorsal hair (Hempelmann 

1947, Hacker 1987, Stannard 1988). Patches of hair grew back discolored. The Army bought 75 head in 

all from ranchers; the 17 most significantly marked were kept at Los Alamos, while the rest were shipped 

to Oak Ridge for long term observation. It was estimated that the doses required to produce such effects 

were between 4,000 and 50,000 R, most likely around 20,000 R (Hacker 1987). 

While there is documentation that samples of airborne particles were taken using ten Filter Queen air 

samplers (modified vacuum cleaners), and soil samples were reportedly taken using large-mouthed jars 

provided to monitoring crew members (Hoffman 1947), we have located no analyses of subsequent 

radiometric or radiochemical analyses of these samples, nor have we located risk assessments that address 

exposures to Trinity workers or to members of the public from internally deposited radioactivity 

following inhalation or ingestion of radioactivity from the Trinity blast. 

Dose Limits and Action Levels for Public Evacuation 

The recovery of data from the Trinity test took precedence over general safety standards (Hacker 1987). 

The 0.1 R d-1 standard for workers in day to day operations at Los Alamos was replaced for Trinity by a 

statement that “no person should (of his own will) receive more than five (5) r at one exposure” (Hacker 

1987). When pressed to decide how high of a radiation exposure to call safe for those with no part in, or 

knowledge of, the Trinity test (that is, members of the public), Hempelmann and Nolan assured 

Bainbridge that a total dose of 68 R spread over two weeks “would certainly not result in permanent 

injury to a person with no previous exposure . . . It would probably not even cause radiation sickness. A 

normal person could probably stand two to three times this amount without sustaining permanent bodily 

damage. Fatalities would not result unless ten or more times this dose were delivered” (Hacker 1987, 

Stannard 1988). Concern focused on immediate hazards, as within the health physics community “the 

thinking had not yet focused on possible long-term effects” (Stannard 1988).It was clear that evacuation 

would require an “extreme emergency” (Hacker 1987). Stafford Warren stated that he would begin to 

worry only if peak exposure rates reached 10 R h-1 , and said that the best approach would be to take 
10-30 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

“measurements for several hours and consider evacuation if total dose reached final total of 60-100 r” 

(Hacker 1987). 

Two days before the test, Warren and Hempelmann agreed to “set the upper limit of integrated gamma 

ray dose for the entire body over a period of two weeks (336 hours) as 75 roentgens” and also agreed on 

an “upper safe limit of radiation ... [of] 15 r/hr at peak of curve” (Hacker 1987). 

Off-Site Monitoring Team Staffing and Positioning 

Four two-man, off-site monitoring teams and one five-man team supervised by the chief off-site monitor 

constituted the off-site monitoring crew led by Joseph Hoffman ( 

Fig. 10-16). The teams were manned as follows, with initial placement as indicated (Hoffman 1947, 

Maag and Rohrer 1982): 

• Alfred Anderson was with Julian Bernacci at Nogal, NM (about 55 mi ESE) 

• Joel Greene was with Charles Nally at Roswell, NM (about 110 mi ESE) 

• Carl Hornberger was with Richard Foley at Fort Sumner (about 140 mi NE) 

• Robert Leonard was with William McElwreath at Socorro, NM (about 30 mi NW) 

• Wright Langham, Phillip Levine, John Magee, Joseph Hirschfelder, and Joseph Hoffman (the 

chief monitor) were at Guard Gate 2. 

The five-man team remained at Guard Gate 2 to assist in evacuation of nearby residents if the cloud from 

the shot drifted toward the northwest. These residents, specifically the Fite Ranch house and the homes in 

the town of Tokay, were roughly 15 and 20 mi northwest of ground zero, respectively (Maag and Rohrer 

1982). From Guard Gate 2, those monitors could also be dispatched toward Carthage, Bingham, Claunch 

(about 50 mi NE), and Carrizozo. 

Fig. 10-16. Recovery team and radiation monitoring crew members after the Trinity blast 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-31

Equipment Used for Off-Site Monitoring

Each off-site monitoring team was provided with the following equipment (Hoffman 1947): 

• A methane filled proportional counter for detecting alpha particle radiation in the presence of 

beta and gamma radiation. 

• A Victoreen Model 247 portable gamma ray survey meter with three ranges. 

• A Hallicrafter Model 5 portable Geiger-Mueller survey meter for gamma radiation and 

mixtures of gamma and beta. 

• Large-mouthed bottles for collecting soil samples. 

• A map showing names and locations of residents within a radius of 40 mi of ground zero. 

Landsverk and Wollan quartz-fiber electrometers (“L & W meters”) were also used, at least at Searchlight 

Station L-8, as were “meters obtained from R. Watts, ” also known as Watts-type meters (Blair et al. 

1945b, Hacker 1987). All off-site monitoring teams were intended to be in radio or telephone contact 

with personnel at Base Camp, but communications were problematic and information could not always be 

shared (Hoffman 1947, Lamont 1965, Maag and Rohrer 1982). 

In addition to the instruments carried in automobiles, the following stationary equipment was used 

(Hoffman 1947): 

• The three shelters (North, South, and West) were equipped with an alpha meter, a betagamma GM meter, and a survey meter. 

• At the Base Camp, a Filter Queen airborne particulate sampler, and a GM recording meter 

were used. 

• At the towns of Tularosa, Hot Springs, San Antonio, and Carrizozo, a Filter Queen, a 

recording beta-gamma meter, and a seismograph were set up. 

Where Off-Site Monitoring Teams Traveled 

Based on observed surface winds, it was thought that contamination was blowing in a line toward the 

northwest from ground zero during the first half hour after the shot. As a result, an early attempt was 

made to monitor around Fite’s Farm just past Guard Gate 2 (see Fig. 10-3). A Military Police officer 

refused to allow the monitoring team to enter that area, however, until permission was received from Base 

Camp. That permission came after it was thought that the cloud had passed, so attention was diverted 

elsewhere. Around 7:11 am, a monitoring team found detectable gamma radiation 19 mi from ground 

zero in the direction of Socorro (toward the northwest) (Hoffman 1947). 

After the path of the cloud appeared to shift toward the northeast, monitors focused on areas along, or 

near, Route 380 past Carthage and between Bingham and Carrizozo (see Fig. 10-12). Monitoring teams 
10-32 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

visited Adobe and White Store to the east along Route 380, and some traveled all the way to Carrizozo. 

Teams traveled north from Bingham on Road 146 to monitor ranches in that area, such as the Coker, 

Lucero, and Sedillo ranches. Just east of Bingham, the highest levels of elevated radioactivity were found 

around Searchlight Station L-8 and rugged areas to its southeast. About 2 mi east of the 146/161 

junction, Road 146 runs through a steep gorge. The highest exposure rates were found there, which led to 

it being called “Hot Canyon” (see Fig. 10-12 and Fig. 10-17). Hoffman wrote “since the canyon was hot, 

extensive measurements could not be made there on account of instrument contamination.” (Hoffman 

1947) 

Puzzled by the high readings reported from Hot Canyon, Drs. Hempelmann and Friedell went to the area 

on July 17, the day after the shot, and discovered an adobe house hidden from the road, about a mile east 

of where the highest readings had been taken (Hacker 1987). An elderly couple lived there with a young 

grandson, several dogs, and assorted livestock (Hoffman 1947, Hacker 1987). The Ratliff ranch had been 

overlooked by the Army, and it was not on the copies of “Palmer’s map of inhabited localities” that 

monitoring crews were given. A second ranch unknown to the army was discovered later. As it turned 

out, a couple with the last name of Wilson lived near the Ratliffs, and early reports confused the two 

residences (Hemplemann 1947, Hoffman 1947, Hacker 1987). 

While there is no record of what the exposure rates were at the Ratliff ranch on shot day, since the 

exposure rates there on the 17th, the doctors decided, were not high enough to warrant “hasty evacuation” 

(Hacker 1987). As mentioned earlier, rancher M. C. Ratliff said that “the ground immediately after the 

shot appeared covered with light snow,” adding that for several days afterward, especially at dawn and 

dusk, “the ground and fence posts had the appearance . . . of being frosted” (Hemplemann 1947, Hacker 

1987). 

Fig. 10-17. USGS Topographic map excerpt showing the area around the Ratliff Ranch 

 (Broken Back Crater, N. Mex., 15-min.series, 1948. Contour interval = 25 ft)

ROAD

146
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-33

Results of Off-Site Monitoring

Results of the off-site monitoring conducted by 44 individuals after the Trinity test are documented in 

handwritten notes, typed transcripts of these notes, and in summary forms (NTA 1946, Hempelmann 

1947, Hoffman 1947, Lamont 1965, Maag and Rohrer 1982, Quinn 1987). Table 10-1 contains a 

summary of field team monitoring results recorded on 16-17 July 1945 that reached intensities of 100 mR 

h-1 or higher. After the trajectory of the cloud shifted toward the northeast, monitors focused mostly on 

areas along, or near, U. S. Route 380 to the east of Carthage and between Bingham and Carrizozo. 

Measured exposure rates first reached 100 mR h-1 at Searchlight Station L-8 around 7:30 a.m. 

Measurements in Bingham (30 km northeast of ground zero) reached 1.5 R h-1 by 8:25 a.m. and peaked at 

3.3 R h-1 at 8:49 a.m. Gamma radiation levels in Adobe (5.4 km southeast of Bingham) were 6.5 R h-1 at 

8:49 a.m. and fell to 1.6 R h-1 by 10:18 a.m. About 3 km farther southeast, in White Store, the highest 

recorded result was 3 R h-1 at 10:30 a.m. 

The highest gamma intensities were found in the “Hot Canyon” area. Monitoring in the area of the 

canyon found gamma intensities up to “the vicinity of 20 R/hr” at 8:30 a.m. that dropped off to 6.0 R h-1

by 1:30 p.m. and 3.8 R h-1 by 1:57 p.m. (Hoffman 1946, NTA 1946, Hoffman 1947). Teams traveled 

north from the Bingham/L-8 area on Route 146 to monitor the Coker, Lucero, and Sedillo ranches. 

Gamma radiation above background was measured in the school yard at Vaughn [96 mi to the northeast 

of ground zero] 7.6 h after the blast, indicating that the cloud traveled no slower than 12.9 mi h-1

(Hoffman 1947). On the day after the blast, exposure rates as high as 300 mR h-1 were measured near 

Corona and Claunch, while exposure rates from 3 to 11 mi north of Vaughn ranged between 0.1 R h-1 and 

“>> 0.1” R h-1 shortly after 3:00 p.m.. At no location greater than 10 mi distant from ground zero was an 

alpha particle count obtained that could easily be distinguished from background with the instruments the 

monitors were using (Hoffman 1947). 

At about 3:30 p.m. on the day of the blast, the recording G-M counter at Carrizozo began to track upward. 

About 15 min later, that meter went off scale on its least sensitive scale, and the monitor notified Base 

Camp by telephone (Hoffman 1946, Lamont 1965). Full scale on that recorder corresponded to 10,000 

counts per minute (“cpm”)(Hoffman 1947). After 1 h, the gamma intensity at Carrizozo was measurable 

on a single-scale Victoreen survey meter that indicated an intensity of 1.5 mR h-1 until the following 

morning (Hoffman 1946, NTA 1946). By 10:00 a.m., the G-M counter reading had decreased to 3,000 

cpm. 
10-34 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

Table 10-1. Exposure rates 0.1 R h-1 or greater measured 16-17 July 1945 near Trinity Site 

Date and Time Off-Site Locationa

Recorded Exposure 

Rate (R h-1) 

7:30 a.m. Searchlight Station L-8 0.1 

7:45 a.m. 11-16 km W of Carthage on US 380 0.2 

8:00 a.m. Searchlight Station L-8 0.5 

8:25 a.m. Bingham 1.5 

8:25 to 9:15 a.m. Searchlight Station L-8 2.0 

8:29 a.m. 0.4 km W of Hansenburg Ranch 0.25 

8:30 a.m. Searchlight Station L-8 0.1 

8:30 a.m. 5.6 km SE of L-8 ("Hot Canyon" area) "vicinity of 20" 

8:35 a.m. Searchlight Station L-8 2 

8:42 a.m. 1.6 km E of Bingham along US 380 1.0 

8:45 a.m. 3.3 km W of Bingham 1.6 

8:45 a.m.c "Cooler spot" retreated to from 8:30 spot in canyon 15 

8:46 a.m. 3.2 km E of Bingham along US 380 2.2 

8:47 to 8:56 a.m. From Searchlight Station L-8 to Hot Canyon 1.2 to 14.5 

8:49 a.m. Bingham 3.3 

8:49 a.m. 6.4 km E of Bingham along US 380 (Adobe) 6.5 

8:50 a.m. 4.8 km E of Searchlight Station L-8 15.0 

8:50 a.m. Hansenburg Ranch 0.45 

8:56 to 9:40 a.m. From Hot Canyon to Searchlight Station L-8 1.5 to 6.5 

9:05 a.m. 4.8 E of Searchlight Station L-8 15.0 

9:30 a.m. Searchlight Station L-8 1.0 

9:40 to 10:15 a.m. N from L-8 to Rte. 41 cutoff to Maxwell Ranch 1.1 to 6.0 

10:00 a.m. 0.8 km S of Hansenburg Ranch 0.8 

10:15 to 10:50 a.m. From Rte. 41 near Maxwell Ranch back to L-8 1.5 to 4.8 

10:18 a.m. 6.4 km E of Bingham (Adobe) 1.6 

10:22 a.m. 6.4 km E of Bingham along US 380 1.5 

10:25 a.m. 9.7 km E of Bingham along US 380 3.0 

10:25 a.m. White Store 2.5 

10:30 a.m. White Store 3 

10:30 to 11:30 a.m. White Store 2.0 

10:33 a.m. 8 km N of Bingham 0.5 

10:40 a.m. Just W of White Store on US 380 3.3 

10:45 a.m. 8 km N of Bingham and 0.25 mi E (Wrye Ranch) 0.2 

10:49 a.m. Just W of White Store on US 380 3.2 

10:54 a.m. 14 km E of Bingham along US 380 0.7 

10:55 a.m. 0.8 km E of Bingham 1.3 

11:00 a.m. Bingham 1.55 

11:00 a.m. 8 km E of Bingham 2.5 

11:00 a.m. 6.4 km E of Bingham 2.0 

11:00 a.m. Bingham 0.5 

11:30 a.m. Bingham 1.7 

11:40 a.m. Bingham 0.65 

11:50 a.m. 6.4 km W of Bingham 0.25 

11:58 a.m.c 1.6 km W of Bingham 0.25 

12:00 p.m. Bingham 0.25 

12:02 p.m.c 1.6 km E of Bingham along US 380 0.15 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-35

Date and Time Off-Site Locationa As recordedb (R h-1) 

Monday, July 16, 1945, continued (after blast at 5:30 a.m)

1:00 p.m. Bingham 1.5 

1:27 p.m. 6.4 km E of Bingham along US 380 0.95 

1:28 p.m. 0.2 km E of White Store on US 380 2.8 

1:30 p.m. White Store 0.15 

1:30 p.m. "Hot Canyon" 6.0 

1:35 to 1:57 p.m. 1.6 to 4.8 km E of Searchlight Station L-8 0.5 to 3.8 

1:47 p.m. 11 km E of Bingham along US 380 1.6 

1:54 p.m. 2.4 km E of Bingham on US 380 1.5 

2:00 p.m. At Bingham 0.5 

2:00 p.m. Rte. 146 just E of junction with Rte. 161 6.0 

2:13 p.m. 8 km N on Rte. 146 from junction Rte. 161 2 

2:30 p.m. 6.4 km W of Bingham along US 380 0.16 

2:30 p.m. 0.27 km E of Sedillo 0.27 

2:30 p.m. Coker Ranch 0.22 

2:40 p.m. 9.7 km NE of Bingham on Rte. 161 3.5 

2:46 p.m. 13 km NE of Bingham on Rte. 161 7 

2:47 p.m. 0.27 km W of Coker Ranch 0.26 

2:50 p.m. Lucero Ranch 0.24 

3:00 p.m. S side of Rte. 161 near junction with Rte. 146 7.0 

3:42 to 3:50 p.m. 11 to 21 km W of Vaughn on Rte. 60 "off scale" 

4:30 p.m. Cedarvale 0.11 

4:48 p.m.c 1.6 km W of Cedarvale on Rte. 42 0.11 

4:53 p.m.c 4 km mi W of Cedarvale on Rte. 42 0.15 

4:59 p.m.c 7.2 km mi W of Cedarvale on Rte. 42 0.13 

7:01 p.m.c 1.6 km E of Willard on Rte. 60 0.11 

10:30 p.m. White Store 0.25 

Tuesday, July 17, 1945 (the day after the blast) 

11:39 to 11:54 a.m.c 25 to 39 km W of Corona toward Claunch 0.10 to 0.15 

12:01 to 12:10 p.m.c 8 to 0 km E of Claunch on Rte. 42 0.11 to 0.18 

12:14 to 12:21 p.m.c 3.2 to 9.7 km S of Claunch 0.11 to 0.19 

12:26 to 12:54 p.m.c 14 to 40 km S of Claunch 0.11 to 0.30 

1:05 to 1:09 p.m.c 9.7 to 5.6 km N of Bingham 0.11 to 0.18 

2:00 p.m. Bingham 0.10 

3:00 p.m. White Store 0.10 

3:10 to 3:30 p.m. 4.8 to 18 km N of Vaughn on Rte. 285 0.1 to ">> 0.1" 

3:30 p.m. 8 km N of Bingham on Rte. 41 toward Monte Prieto 0.19 

3:30 to 4:02 p.m. 1.6 to 26 km N of Vaughn toward Encino > 0.1 

4:30 to 6:00 p.m. 24-40 km N of Bingham on Rte. 41 to Monte Prieto 0.19 to 0.30 

5:50 to 6:36 p.m. 42-47 km E of Broadway (Trinity access) on US 380 0.11 to 0.5 

6:30 p.m. "Hot Canyon" 0.5 

7:30 to 8:00 p.m. 8 to 0 km N of Claunch on road from Gran Quivira 0.10 to 0.19 

 

 c Measurement time estimated based on odometer readings and times specified for nearby measurements. 
10-36 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

Evacuation Policy and Decision Making 

Shortly before the Trinity blast, surface winds were blowing toward the North Shelter (Hoffman 1946). 

About 12 min after the shot, a “Watts’ meter” at North Shelter indicated a rapid increase in radiation 

intensity because of a faulty zero setting (Hoffman 1946, Hoffman 1947, Maag and Rohrer 1982). When 

a remote ionization “sentinel” indicated a rapid increase in radiation, immediate evacuation of all 

personnel at that shelter was advised. Some personnel evacuated with such urgency that their cars were 

riding their hubs when they reached Base Camp 25 km south (Lamont 1965) While film badges worn by 

personnel in the shelter showed no exposures over 100 mR, the subsequent detection of radioactivity in 

the area was seen as evidence that part of the cloud had passed over but deposited little radioactivity on 

the ground (Maag and Rohrer 1982, Hacker 1987). Gamma intensities of 10 to 20 mR h-1 were measured 

around North Shelter 2 h after evacuation (Bainbridge 1976). 

Most of the Army evacuation detachment and five radiological safety monitors that were stationed near 

Guard Post 2 northwest of ground zero remained there until a platoon was sent to Bingham while 

monitors surveyed that area (Maag and Rohrer 1982). When the chief monitor learned of the exposure 

rates as high as 3.3 R h-1 at Bingham, Adobe, and White Store, he projected that total exposures in that 

region might approach the allowed limit. The exposure rate of 6.5 R h-1 taken 4 mi east of Bingham at 

8:49 a.m. was judged to be “getting close to the evacuation limit.”i

 A message was sent by courier to 

Base Camp that integrated gamma doses had been projected at 90% of tolerance (Hoffman 1947, Hacker 

1987). Medical experts were summoned, exposure rates decreased as the dust dispersed and settled, and 

no evacuation of the area was conducted. The evacuation detachment was dismissed at 1:00 p.m. on shot 

day “when it became evident that evacuations would not be undertaken” (Maag and Rohrer 1982). 

After the recording beta-gamma meter at Carrizozo went off scale around 4:20 p.m. on test day, scientists 

and military officials considered whether Carrizozo should be evacuated. They held off taking that action 

for some additional monitoring and within an hour, fallout readings dropped, it was concluded that the 

radioactive cloud had passed over, and no evacuation was ordered (Hoffman 1946, NTA 1946, Lamont 

1965, Hacker 1987). As the cloud drifted beyond the 15 mi radius, such as north of Bingham and around 

Carrizozo, monitors often overreached the limits of radio communication with Base Camp (Bainbridge 

1976). As officials at Base Camp were advising Washington that the danger from radioactive fallout was 

diminishing, they were out of communication with monitors that were measuring fallout in areas as 

distant as 112 mi to the north (Lamont 1965). 

 

i

Notes taken by radiation monitors Robert R. Leonard and W.J. McElwreath, 16 July 1945. LANL Archives Collection A-84-

019, Box 8 Folder 1.
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-37

Historical records indicate that pressures to maintain secrecy and avoid legal claims led to decisions that 

would not likely have been made in later tests. Even though exposure rates, total exposures, and alpha 

count rates exceeding pre-established limits were measured and projected; a “cover story” was in place 

that would have provided an avenue for relatively inconspicuous evacuation of selected residents; and 

evacuation personnel, vehicles, shelters, and supplies were on standby, no evacuations of members of the 

public were conducted. 

In a July 31, 1945 War Department memorandum to Dr. Louis Hempelmann (reproduced in Hempelmann 

1947), Lt. Daniel Dailey of the Corps of Engineers refers to requests from Hempelmann that “the health 

of persons in a certain house near Bingham, N.M. be discretely investigated.” Over the 2 y following 

Trinity, at least seven visits were made to the Ratliff ranch by LANL and MED medical personnel, health 

physicists, and Army Intelligence agents, “under suitable pretext,” to check on the visible condition of the 

residents (Hempelmann 1947, Hoffman 1947). Even after the atomic bombs were dropped, the atomic 

bomb project and the roles of Los Alamos and Trinity were described publicly, and the need for secrecy 

diminished, the reasons for these visits were not disclosed to the residents. 

Monitoring practices and protective action decision processes after the Trinity blast were clearly focused 

on the immediate hazards of radiation exposure. In the health physics community of the MED “the 

thinking had not yet focused on possible long-term effects” (Pierre 1972, Hacker 1987, Stannard 1988). 

Medical surveillance of ranchers was limited to casual observation of external appearances and veiled, 

nonspecific questioning regarding any health complaints. Although concern was voiced for the health 

status of at least one family, no evidence was found of steps being taken to reduce exposures to ranchers 

who continued to live in the fallout zone after July 1945. This was in spite of the fact that soil and the 

grasses eaten by grazing livestock were particularly radioactive in the area of Hot Canyon. In retrospect, 

Hempelmann acknowledged that “a few people were probably overexposed, but they couldn’t prove it 

and we couldn’t prove it. So we just assumed we got away with it.” (Hempelmann and Henrickson 1986) 

After the Trinity test, Los Alamos scientists estimated effective rates of decay and total (external) doses 

delivered for several public areas (Hoffman 1947). LASL scientists defined the “geometrical dose” as the 

integrated dose under the maximum exposure rate that preceded the steady decay (Hoffman 1947). The 

geometrical dose was seen to represent “high intensity, short duration dose” that “can be a severe health 

hazard because it is delivered in a short time interval.” The integrated dose used by Los Alamos scientists 

in 1945 did not include the area under the maximum, but corresponded to the “long, low intensity decay 

that follows [the maximum]” out to a point in time 14 d after the blast (Hoffman 1947). The maximum 

tolerable values of geometrical dose and integrated gamma ray dose for the entire body over a period of 

14 d were 50 and 75 R, respectively (Hoffman 1947). 
10-38 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

Table 10-2 shows the geometrical doses, integrated doses, and total doses (geometrical plus integrated) 

that were reported by Hoffman (1947) for Hot Canyon, White Store, and Bingham. Correction factors for 

shielding by house structures were based on measurements in Los Alamos (wooden frame) and Bingham 

(adobe) houses on 19 July and 17 August 1945, respectively (Hoffman 1947). Based on monitoring done 

on and beyond the day after the blast, Los Alamos scientists estimated doses at the Ratliff residence 

(Hempelmann 1947). For the first 14 d after the blast, the geometrical dose was estimated to be 15 R, the 

dose from the ground 32 R, and the total accumulated dose (waist high) 47 R– said to be a factor of 33 

above the tolerance. Radioactivity at the nearby Wilson ranch was estimated to be 75% of that at the 

Ratliff ranch (Hempelmann 1947). 

Table 10-2. External gamma ray exposure values calculated for several public areas 

after the Trinity test by Los Alamos scientists (Hoffman 1947) 

Location “Geometrical 

Dose” (R) 

“Integrated 

Dose” (R) 

“Total Dose” 

after 14 d (R) 

“Hot Canyon” 

 On the grounda

 Corrected for house shieldingb

 Corrected to torso levelc

 24 

 24 

 15 

115 

 62 

 41 

139 

 88 

 56 

Torso level, no house shieldingd 28 76 100 

White Store

 On the ground 

 Corrected for house shielding 

 Corrected to torso level 

 8.4 

 8.4 

 4.2 

21.8 

11.8 

 5.8 

30.2 

20.2 

10 

Torso level, no house shielding 7.8 10.7 19 

Bingham

 On the ground 

 Corrected for house shielding 

 Corrected to torso level 

 3.3 

 3.3 

 1.7 

24 

 0.3 

 6.5 

27.3 

17.3 

 8.1 

Torso level, no house shielding 3.1 12 15 

a Estimated at 10 cm above the ground surface. 

b

 Gamma dose reduced by 46% to account for shielding by an adobe house. 

 c

 Dose at torso level estimated to 50% of the dose at 10 cm above ground level during the 2 weeks. 

d

 “Corrected to torso level” values divided by 0.54 to estimate torso level with no house shielding.. 

Assessments of Trinity Fallout Performed by Others 

Exposure rate contour lines based on the data collected by the town monitoring crews in 1945 based on 

modeling by the Weather Service Nuclear Support Office (Quinn 1987) and extended by Lawrence 

Livermore National laboratory (Cederwall and Peterson 1990) are presented in Figures 10-18 and 10-19. 

The lines in Fig. 10-18 that extend roughly east-west at five distances from ground zero indicate 

approximate locations of the edge of the cloud at times from 2 to 14 h after the shot. The extensions of 

the fallout contours in Fig. 10-19 show the contamination leaving New Mexico into Colorado and the 

northwest portion of Oklahoma. 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-39

Fig. 10-18. The 0.01, 0.1, 2, and 10 R h-1 contours from the Trinity test at t + 1h, as analyzed by the 

Weather Service Nuclear Support Office (WSNSO, Quinn 1987). BGZ = ground zero. 

Fig. 10-19. Extension of Trinity fallout pattern as exposure rate, mR h-1 at t + 12 h, based on WSNSO 

analysis (Quinn 1987) extended (dotted lines) with LLNL modeling (Cederwall and Peterson 1990) 
10-40 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

A source term for the Trinity event was calculated by scientists at Lawrence Livermore National 

Laboratory (Hicks 1985), and fallout patterns were reconstructed on behalf of the USDOE’s Off-Site 

Radiation Exposure and Review Project (ORERP) (Quinn 1987). Unlike for the nuclear explosions at the 

Nevada Test Site, doses have not been reconstructed for the Trinity event, due primarily to scarcity of 

data (Anspaugh 2000). 

All evaluations of public exposures from the Trinity blast that have been published to date have been 

incomplete in that they have not reflected the internal doses that were received by residents from intakes 

of airborne radioactivity and contaminated water and foods. Some unique characteristics of the Trinity 

event amplified the significance of those omissions. Because the Gadget was detonated so close to the 

ground, members of the public lived less than 20 mi downwind and were not relocated, terrain features 

and wind patterns caused “hot spots” of radioactive fallout, and lifestyles of local ranchers led to intakes 

of radioactivity via consumption of water, milk, and homegrown vegetables, it appears that internal 

radiation doses could have posed significant health risks for individuals exposed after the blast. 

Gaps in Information about the Trinity Test 

In retrospect, pioneer health physicist J. Newell Stannard identified two main gaps in the description of 

Trinity event (Stannard 1988). The first deals with the characterization of residual plutonium, which was 

present due to the fact that the efficiency of the device was not 100 percent. The Trinity “Gadget” 

contained 6 kg of 239Pu as its sole fissile material (USDOE 2001). The 21 kt yield of the blast (USDOE 

2000) corresponds, at 1.45×1023 fissions per kt (Glasstone and Dolan 1977), to 3.05×1024 atoms or 1.21 

kg of 239Pu fissioned. That indicates that approximately 4.8 kg of 239Pu remained unfissioned and was 

dispersed in the environment. It was present in the crater and partly scattered around the environment in 

the fallout. Monitors did find some plutonium─ it was not measured very carefully near shot time, but its 

presence was hinted at in the initial surveys (Stannard 1988). The instruments used by field monitoring 

teams were acknowledged to be incapable of measuring alpha contamination in the environment to the 

desired sensitivities (Hoffman 1947). A full-scale survey of the Trinity site was not conducted until three 

years later, by a group from the UCLA medical school. 

The second gap is the lack of any measures for detection of internally deposited radionuclides, such as 

bioassay, nose swabs, etc. At the time, nose swab collection and analysis was the main technique at Los 

Alamos of monitoring for inhalation of radioactive material, including in D Building where the plutonium 

hemispheres for the Trinity device were manufactured (Hempelmann and Langham 1953). There 

certainly were instances of inhalation of airborne radioactivity by members of the public who were in the 

path of the Trinity cloud or were near deposited radioactivity that was resuspended, and water and food 

products were also contaminated. For example, the Ratliff home in Hot Canyon used its tin roof to collect 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-41

water into a cistern that served as the family’s drinking water supply. This was a common practice in the 

area (Allen 2008). There was rain in the area the night after the shot, which means that deposited 

radioactivity was likely carried into their drinking water (Appendix II in Hoffman 1947). 

Some Lessons about Off-site Impacts Learned from the Trinity Test 

From the Trinity test, it was learned that detonating a nuclear explosive device close to the ground 

increases the radioactive fallout from the event. Detonating devices at higher elevations results in the 

dispersion of less radioactivity, while yielding more blast power. Based on experience with the Trinity 

event, and expanded upon in test series conducted in the Pacific during 1946 and 1948, the potential for 

exposure of workers and members of the public to fallout became known and appreciated (Anspaugh 

2000). 

It was also learned that “hot spots” are important phenomena when radioactive clouds disperse, and their 

occurrence can be influenced by local terrain features and air flow patterns. 

The Trinity Site was judged to be too small for additional atomic tests to be conducted there. General 

Groves concluded that the Trinity test site “is too small for a repetition of a similar test of this magnitude 

except under very special conditions” (Hacker 1987). He proposed finding a larger site, “preferably with 

a radius of at least 150 miles without population” [compared to about 15 miles at Trinity] for any future 

test. 

Follow-Up Studies of Trinity Fallout 

After the Trinity blast, several monitoring teams continued through the remainder of 1945 to periodically 

traverse roads to the northeast of the site to measure and record exposure rates. Records of survey trips 

were found for excursions on 12 additional days in July, eight in August, two in November, and four in 

December (Hoffman 1946, NTA 1946, Hoffman 1947). 

In August 1947, scientists from the University of California, working with Wright Langham from LANL, 

conducted a limited survey of a 26,000 ha (100 mi2

) area near the Trinity Site (Overstreet et al. 1947). 

Between 1949 and 1978, teams from UCLA and the U.S. Environmental Protection Agency (USEPA) 

published reports of studies of larger zones of local Trinity fallout (Warren and Bellamy 1949, Bellamy et 

al. 1951, Gillcoly et al. 1951, Leitch 1951, Nishita et al. 1957, Douglas 1978). The earliest UCLA 

surveys were limited to beta-gamma measurements. Measurements of gross alpha radioactivity in 

airborne particles (assumed to be plutonium) were first reported in 1951, as were alpha measurements of 

chemically separated plutonium from plants and soil. The first of these studies to include isotopic 

analyses of plutonium in environmental media (soil and air) was published by Douglas (1978) for samples 

collected in 1973 and 1974, over 28 y after the detonation. 
10-42 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

Characteristics of members of the public near the Trinity Site

Population, ethnicity, diet, housing, and lifestyle characteristics of residents near the Trinity test site 

around 1945 were described based on, except where noted otherwise, interviews of current residents and 

historians (Allen 2008) and information from reviewed documents. Based on interviews of local 

residents and historians, the typical ethnic compositions of ranchers, sheepherders, and cowboys near the 

Trinity Site around 1945 were estimated to be as shown in Table 10-3. Both ranchers and people who 

lived in towns used the most readily available construction materials. As shown in Table 10-4, adobe was 

by the far the most common building material for homes and work places. Barn roofs were typically mud 

while home roofs were usually metal to facilitate water collection. In towns such as Carrizozo, most 

buildings were adobe, but homes made of wood frame construction and bricks were also present. 

. 

Table 10-3. Estimated distribution of ethnicities for residents near the 

Trinity Site circa 1945 based on LAHDRA interviews (percentages) 

Class of Persons Angloa Spanish Native 

American 

Ranchers 90 10 0 

Sheepherders 0 100 0 

Cowboys 80 20 0 

 aNon-Hispanic white persons 

Table 10-4. Estimated distribution of construction types for buildings 

near the Trinity Site circa 1945 based on LAHDRA interviews 

(percentages) 

Building Type and Setting Adobe Wood Stone Brick 

Ranch homes 85 10 10 0 

Homes in towns 75 22 1 2 

Ranch workplaces 80 15 5 0 

Workplaces in towns 75 23 0 2 

If it was daylight, ranchers and their hired hands were typically outside working. Breakfast would 

typically be eaten while it was still dark so work could begin at first light. Meals would have been eaten 

inside. Since the Trinity test occurred during the summer, children would also have been outside during 

daylight hours either working or playing. While ranch wives spent the bulk of their time outdoors tending 

to laundry, gardening, or helping with the livestock, wives typically spent more time inside than men 

preparing meals, canning food, and processing milk. 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-43

Cattle and sheep were commonly raised by ranchers in the area, and each ranch typically had horses, 

chickens, and a garden. Some ranchers also had hogs for their personal use. The Ratliff ranch maintained 

a herd of 200 goats and some turkeys and donkeys (Hempelmann 1947, Hoffman 1947). A long-time 

resident of the area indicated that these goats were raised for their hair, not their milk. If drought caused 

lack of forage, livestock was sold. 

Ranchers and their hired hands had similar diets. Ranchers in the area typically collected rain water off 

metal roofs into cisterns, like shown in Fig.10-20, as their source of drinking water. Local ground water 

contained excessive mineral content that made it unsuitable for human consumption, but it was used to 

water livestock. Beans and potatoes were grown in vegetable gardens, but were often supplemented with 

purchases made in town. Flour, sugar, and other staples were bought in town. Produce, including peas, 

root crops, squash, and corn, was grown in gardens. Moreover, some ranchers had fruit trees. Produce 

that was not eaten fresh was canned in glass jars, with the goal to put up enough to take the family 

through to the next harvest. The primary fresh meat sources were deer and chickens, which also provided 

eggs. If the ranchers ate any beef, it was most likely from the grown calf from their dairy cow. 

Essentially all ranchers had a dairy cow, and ranch wives processed the milk to make other dairy products 

used on the ranches. 

Fig. 10-20. A system for collection of water off the roof of a residence on the Black Hills 

Ranch, formerly the Nalda Ranch, east-northeast of the Trinity Site. The cistern to the 

left, which was damaged by the Trinity blast then repaired, is still in use today. 
10-44 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

The ranches near the Trinity Site did not have electricity until after the war, but most had an icebox. Ice 

was purchased in town and stored underground at the ranch houses. Some ranchers might have had 

butane-powered refrigerators or coal-oil-powered refrigerators and stoves. Town dwellers bought their 

groceries, including milk products, from grocery stores. Town residents had electricity and refrigerators, 

and water was piped to their homes. Ranchers and historians have little knowledge of local ranchers who 

drank goat milk, except for one man who reportedly purchased goat milk in Belen, New Mexico. There 

has been no specific evidence found that indicates that the Ratliff family drank, sold, or shared goat milk. 

References 

Albuquerque Journal News. Trinity: 50 Years Later, An Albuquerque Journal Special Reprint. 

Albuquerque Publishing Company; 1995. 

Allen CA. Trinity test residence history/interviews. San Francisco, CA: ChemRisk, Inc.; 2008. 

Anspaugh LR. Radiation Doses to the Population of the Continental United States from the Ingestion of 

Food Contaminated with Radionuclides from Nuclear Tests at the Nevada Test Site, February 

4th, 2000. Rockville, MD: Report from the National Cancer Institute 2000. 

Bainbridge KT. Trinity. Los Alamos, New Mexico: Los Alamos Scientific Laboratory; LA-6300-H; 

1976. Repos. No. 3173. 

Bellamy A, Held E, Taylor J, Olafson J, Leitch J, Neel J, Larson K, Dunn W, Gross W. Alpha activity 

due to the atomic bomb detonation at Trinity, Alamogordo, New Mexico. Los Angeles, 

California: University of California at Los Angeles; UCLA-108; 1951. 

Blair J, Frisch D, Katcoff S. Detection of Nuclear-Explosion Dust in the Atmosphere. Los Alamos, New 

Mexico: Los Alamos Scientific Laboratory; LA-418; 1945a. 

Blair J, Kupferberg M, Nedzel A. Section L-8 Searchlight Detachment Cloud Observations and Radiation 

Measurements; Memorandum to Joseph G. Hoffman. Los Alamos, NM: Los Alamos Scientific 

Laboratory; 1945b. Repos. No. 5686. 

Cederwall RT, Peterson KR. Meteorological modeling of arrival and deposition of fallout at intermediate 

distances downwind of the Nevada Test Site. Health Phys 59: 593-601; 1990. 

Douglas RL. Levels and Distribution of Environmental Plutonium Around the Trinity Site. Los Alamos, 

NM: Los Alamos National Laboratory; ORP/LV-78-3 1978. Repos. No. 5991. 

Frisch O. What little I remember. New York, New York: Cambridge University Press; 1979. 

Gillcoly B, Olafson J, Neel J, Larson K, Gordon S, Dunn WF. The 1949 and 1950 radiological soil survey 

of fission product contamination and soil plant Interrelationships of areas in New Mexico affected 

by the first atomic bomb detonation Los Angeles, California: University of California at Los 

Angeles; UCLA-140; 1951. 

Glasstone S, Dolan PJ. The Effects of Nuclear Weapons. Third ed. Washington, DC: U.S. Department of 

Defense, U.S. Energy Research and Development Agency; 1977. 

Groves LR. Memorandum for the Secretary of War (Stimson) from the Commanding General July 18th, 

1945. Manhattan District Project. 1945. 

Groves LR. Now It Can Be Told: The Story of the Manhattan Project. New York, NY: Da Capo Press; 

1962. 

Hacker BC. The Dragon's tail: Radiation Safety in the Manhattan Project, 1942-1946. Berkeley, 

California: University of California Press; 1987. 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 10-45

Hawkins D. Manhattan District History, Project Y - The Los Alamos Project, Vol. 1 - Inception Until 

August 1945. Los Alamos, NM: Los Alamos Scientific Laboratory; LAMS-2532 (Vol. 1); 1961. 

Repos. No. 5680. 

Hempelmann LH. Nuclear Explosion 16 July 1945, Health Physics Report on Radioactive Contamination 

throughout New Mexico, Part B: Biological Effects. Los Alamos, New Mexico: Los Alamos 

Scientific Laboratory; LA-638; 1947. Repos. No. 2257. 

Hempelmann LH, Henrickson PW. Transcript of an oral history interview of Dr. Louis Hempelmann 

conducted by Paul Henrickson on 31 January 1986; LANL Archives Collection A-2006-006. 

1986. Repos. No. 8008. 

Hempelmann LH, Langham W. Determination of systemically deposited plutonium in laboratory 

personnel and a simple qualitative test for exposure to airborne radioactive material. Los Alamos, 

New Mexico: Los Alamos National Laboratory; AECU-2663; 1953. 

Hemplemann LH. Nuclear Explosion 16 July 1945: Health Physics Report on Radioactive Contamination 

Throughout New Mexico, Part B: Biological Effects Los Alamos, NM: Los Alamos Scientific 

Laboratory; 1947. Repos. No. 2741. 

Hicks HG. Results of Calculations of External Gamma Radiation Exposure Rates from Fallout and the 

Related Radionuclide Compositions - The Trinity Event. Livermore, California: Lawrence 

Livermore National Laboratory; UCRL-53705; 1985. 

Hirschfelder JO, Kamm R, Magee J, Sugarman N. Fate of the Active Material After a Nuclear Explosion 

August 20th, 1945. Los Alamos, NM: Los Alamos National Laboratory; LAMS-277; 1945. 

Repos. No. 1613. 

Hoddeson L, P.W. H, Meade R, Westfall C. Critical assembly - A technical history of Los Alamos during 

the Oppenheimer years, 1943-1945. Cambridge University Press; 1993. 

Hoffman JG. Nuclear explosion 16 July 1945: health physics report on radioactive contamination 

throughout New Mexico following the nuclear explosion. Part C: Transcript of radiation 

monitor's field notes, film badge data on town monitoring. Los Alamos, NM: Los Alamos 

Scientific Laboratory; 1946. Repos. No. 5686. 

Hoffman JG. Nuclear explosion 16 July 1945: health physics report on radioactive contamination 

throughout New Mexico following the nuclear explosion, Part A: Physics. Los Alamos, NM: Los 

Alamos Scientific Laboratory; LA-616; 1947. Repos. No. 1580. 

Jones WC. Manhattan: The Army and the Atomic Bomb. Washington, DC: Center of Military History, 

United States Army; 1985. 

Kistiakowsky G. Reminiscences of Wartime Los Alamos. Reminiscences of Los Alamos; 1980. 

Lamont L. Day of Trinity: The Dramatic Story of the Los Alamos Atomic Explosion and the Men Who, 

in July 1945, Opened the Nuclear Age. New York: Atheneum; 1965. 

LASL. Los Alamos 1943-1945; The Beginning of an Era. Los Alamos, NM: Los Alamos Scientific 

Laboratory; LASL-79-78; 1979. Repos. No. 4048. 

Leitch JL. Summary of Radiological Findings in Animals from Biological Surveys in 1947, 1948, 1949, 

1950; February 14. Los Angeles, CA: University of California, Los Angeles; UCLA-111; 1951. 

Repos. No. 5995. 

Maag C, Rohrer S. Project Trinity 1945-1946, final report. Washington, DC: U. S. Defense Nuclear 

Agency, United States Atmospheric Nuclear Weapons Tests, Nuclear Test Personnel Review; 

DNA Report 6028F; 1982. Repos. No. 6416. 

Merlan T. Life at Trinity Base Camp. Prepared for the White Sands Missile Range by Human Systems 

Research, Inc; White Sands Missile Range Archaeological Research Report No. 01-07; 2001. 

Morrison P. Former Worker Pit Assembly (G-1) for Project Trinity; Transcript of Videotaped Interview 

with Phillip Morrison on November 30th, 1999. Los Alamos, NM: Public Affairs Office, Los 

Alamos National Laboratory; 1999. 
10-46 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 10 

National Atomic Museum. The First Atomic Test; Chapter 1 [online]. Available at: 

http://www.worldwideschool.org/library/books/hst/northamerican/TrinitySite-I/chap1.html. 

Nishita H, Olafson J, Larson K. The distribution of plutonium in the soils of central and northeastern New 

Mexico as a result of the atomic bomb test of July 16, 1945 West Los Angeles, California: 

University of California at Los Angeles; UCLA-406; 1957. 

NTA. Hand written field notes taken by field monitoring teams after the Trinity explosion. Las Vegas, 

NV: Nuclear Testing Archives; NVO-59707; 1946. 

Overstreet R, Jacobson L, Larson K, Huntington G. Trinity survey program. Los Angeles, California: 

University of California; AM-2843; 1947. 

Pierre AJ. Nuclear Politics: The British Experience with an Independent Strategic Force, 1939-1970. New 

York, New York: Oxford University Press; 1972. 

Quinn VE. Analysis of nuclear test Trinity radiological and meteorological data. Las Vegas, NV: National 

Oceanic and Atmospheric Administration, Weather Service Nuclear Support Office; 1987. 

Radiochemistry Society. Nuke Tests, Trinity Test - July 16th, 1945 [online]. Available at: 

http://www.radiochemistry.org/history/nuke_tets/trinity/index.html. 

Rosen TL. The Atomic City - A Firsthand Account by a Son of Los Alamos. Austin, TX: Sunbelt Eakin; 

2002. 

Santa Fe New Mexican. History in the Making: Pilot Accidentally Witnessed First A-Bomb Explosion 

Santa Fe New Mexican News; 2005. 

Savage J, Storm B. Reach to the unknown, The Trinity story. The Atom 2; 1965. 

Stannard JN. Radioactivity and Health, a History. Office of Scientific and Technical Information; 1988. 

Sugarman N. 100-Ton Test: Radiochemistry. Appendix 61 to LA-1027 (originally published as LA290). 

LA-290; 1945. Repos. No. 1613. 

Szasz F. The day the sun rose twice. University of New Mexico Press; 1984. 

USDOE. “Trinity Site” visitor brochure. U.S. Department of Energy, National Atomic Museum; 1994. 

USDOE. United States Nuclear Tests July 1945 through September 1992. Las Vegas, NV: U.S. 

Department of Energy, Nevada Operations Office; DOE/NV--209-REV 15; 2000. 

USDOE. Restricted data declassification decisions 1946 to the present (RDD-7). U.S. Department of 

Energy; 2001. 

Warren S, Bellamy A. The 1948 Radiological and Biological Survey of Areas in New Mexico Affected 

by the First Atomic bomb Detonation. Los Angeles, California: University of California at Los 

Angeles; UCLA-32; 1949. 

Warren SL. Report on Test II at Trinity, July 16th, 1945, to the Attention of Major Gen. Groves. 1945. 

Webb JH. The fogging of photographic film by radioactive contaminants in cardboard packaging 

materials. Physical Review 76: 375; 1949. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11 11-1

Chapter 11: Beryllium Use at Los Alamos 

Beryllium has been used at Los Alamos since 1943 in various operations related to nuclear reactors and 

weapons production, including machining, fabrication and testing of components. The discovery of 

beryllium in 1798 was credited to the French chemist Louis Nicolas Vauquelin upon formulation of 

beryllium hydroxide. Elemental beryllium, however, was not isolated prior to two independent 

experiments in 1828. Beryllium occurs naturally only as the 9

Be isotope, although five additional isotopes 

are produced artificially, 6

Be to 11Be (IPCS 1990). 

Beryllium is the lightest of all solid and chemically-stable substances and has an unusually high melting 

point of 1287 C (HSDB 2005). The metal has a number of chemical properties in common with 

aluminum, including a very high affinity for oxygen. On exposure with air, a thin film of beryllium 

oxide forms on the surface of bare metal, providing the metal with high resistance to corrosion. This film 

also renders beryllium resistant to water and cold oxidizing acids (IPCS 1990). 

Neutron emission upon alpha-bombardment is the most important of the nuclear physical properties 

associated with beryllium. Its low neutron absorption properties and its high-scattering cross-section 

distinguish beryllium as a suitable moderator and reflector of structural material in nuclear facilities. 

While most other metals absorb neutrons from the fission of nuclear fuel, beryllium atoms only reduce the 

energy of such neutrons and reflect them back into the fission zone (IPCS 1990). 

Industrial Uses of Beryllium 

Interest in and application of beryllium grew after the discovery in the 1920s that addition of only two 

percent beryllium to copper resulted in an alloy that was six times stronger than copper alone (IPCS 1990, 

Becker and Vigil 1999). Metallic beryllium was examined as a possible tamper material as early as 1943 

in the U.S. nuclear weapons program. Enough beryllium had been accumulated at Los Alamos by May 

1946 to allow for critical mass experiments (Hanson 1995). However, use of large quantities in the 

nuclear weapons program in the 1940s would have exhausted the entire U.S. supply of the metal. 

Beryllium was used as a substitute for gold or natural uranium reflectors in early atomic weapons, thereby 

saving much weight and money (Hanson 1995). 

Beryllium metal did not become readily available to American industry until 1957. Since that time, 

beryllium use has been widespread as an additive to glass, ceramics and plastics; in camera shutters, 

submarine cable housings, and dental prostheses; and in beryllium-copper alloys in products such as golf 
11-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11

clubs, springs, pivots, and pinions. Beryllium is additionally used in the semiconductor, precision 

electronics, spacecraft, and missile manufacturing industries (IPCS 1990). 

A timeline depicting events of importance regarding uses of beryllium in general and at AEC/DOE 

facilities, uses at Los Alamos, states of knowledge regarding health effects, and promulgation of 

guidelines and regulatory limits is presented in Table 11-1. 

Records Searches for Beryllium Information 

The project team has identified few reports written during the period of historical beryllium operations at 

LANL other than H-Division Progress Reports. Most of the early H-Division reports mention beryllium 

air sampling in specific LANL buildings, but no details regarding the associated beryllium operations are 

provided. Several documents were located in the LANL Records Center and Report Collection that 

provide summaries of historical monitoring activities associated with beryllium metal machining and 

firing site operations (Mitchell and Hyatt 1957, Becker and Vigil 1999). A Johns Hopkins report 

(JHSPH 1999) was recommended to the project team by a former LANL worker, and a copy was 

provided by M. Cadorette, Project Coordinator, after initial contact with the Energy Employees 

Occupational Illness Compensation Program Act (EEOICPA) office in Española, NM. 

Very little historical stack monitoring data for beryllium have been located by the project team. If stack 

releases of beryllium were not routinely monitored, indoor air monitoring data might be useful for 

estimating source terms for beryllium releases to the environment. 

Operations Involving Beryllium Release to the Environment 

Two types of operations at LANL, machining and firing tests, have resulted in releases of beryllium to the 

environment. The machining, grinding, sanding and general handling of beryllium components typically 

occurred in machine shops or experimental laboratory settings. Dynamic testing has involved use of 

beryllium and other materials in explosive tests in the open air or with various forms of containment or 

confinement. Industrial Hygiene records indicate that activities involving beryllium have been performed 

at 20 different Technical Areas between 1943 and 1980. The main facilities that housed beryllium 

operations within the Original Technical Area are shown in Fig. 11-1. Beryllium metal was processed in 

the shops and metallurgical labs, and soluble beryllium salts were handled in the chemical labs (JHSPH 

1999). 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11 11-3

Table 11-1. Beryllium timeline 

 1933 First description of acute beryllium disease (Weber and Engelhardt 1993) 

 1943 Chemical pneumonia reported in workers extracting beryllium from beryl ore (Van Ordstrand et al. 1943)  1943 U.S. Public Health Service publishes NIH Bulletin 181 stating that beryllium metal is not toxic (Hyslop et al. 1943) ~1944 Beryllium machining began in V Shop at LASL’s Original Technical Area  1946 First cases of chronic beryllium disease (CBD) in fluorescent light bulb workers (Hardy and Tabershaw 1946)  1947 United States Atomic Energy Commission (USAEC) is formed  1949 USAEC establishes a 2 μg m-3 occupational exposure limit at their facilities (Eisenbud et al. 1949)  1949 Beryllium machined in V Shop Annex (also known as the “Old Beryllium Shop”) at LASL  1952 Exhaust system enlarged in Old Beryllium Shop at LASL  1953 Beryllium is machined in the new beryllium shop at LASL and the old beryllium shop is closed  1957 ACGIH proposes a 2 μg m-3 Threshold Limit Value exposure limit (ACGIH 2006)  1958 USAEC contracts with Brush Wellman for 200,000 lbs of beryllium per year (Stange 2005)  1959 Health protection in beryllium facilities; summary of 10 y of experience (Breslin and Harris 1958, Breslin and Harris 1959)  1971 OSHA adopts the 2 μg m-3 permissible exposure limit (PEL) 8-hr TWA (time-weighted average) (OSHA 2008)  1973 National Emission Standard for beryllium in ambient air 0.01 μg m-3 averaged over a 30-d period (USEPA 2004)  1977 NIOSH recommends a 0.5 μg m-3 limit to OSHA, classifies beryllium as a potential occupational carcinogen (USDOE 1999) based on 

an increased risk for lung cancer associated with exposure to high levels of beryllium in the workplace before the 1950s (ACGIH 2006) 

 1984 First case of CBD at the USDOE Rocky Flats Plant (Stange 2005)  1998 ACGIH proposes a 0.2 μg m-3 TLV®-TWA to minimize CBD and sensitization  1998 USEPA establishes a reference concentration of 0.02 μg m-3 based on sensitization and progression to CBD (USEPA 2009)  1999 USDOE establishes a 0.2 μg m-3 action level that triggers workplace precautions and control measures (USDOE 1999)  2000 Energy Employees Occupational Illness Compensation Program Act (EEOICPA) passed by Congress  2001 EEOICPA makes first CBD claim award (Stange 2005)  2007 ACGIH proposes a 0.05 TLV®-TWA and a 0.2 TLV®-STEL (short term exposure limit) (NRC 2008) 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11 11-4 

Fig. 11-1. December 1946 view, looking south, of the Original Technical Area with buildings that had significant beryllium involvement identified; 

Buildings Gamma, V, and M on the left, B and Q in the center, and Sigma, I, and Delta toward the right. Based on photo LAHM-P1990-40-1 courtesy of the Los 

Alamos Historical Society. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11 11-5 

Machining and Component Production Operations 

The first production job assigned to the metallurgy groups at Los Alamos involved the manufacture of 

specially-shaped high-density beryllium oxide bricks required for the Water Boiler reactor. Production of 

these bricks was accomplished by hot-pressing beryllium oxide powder into a graphite die or mold of 

suitable shape. The die and contents were heated to approximately 1,700 C using an induction coil 

connected to a high-frequency converter under a pressure of 1,000 psi. This process consolidated the 

semi-plastic beryllium oxide powder into a dense coherent mass in the shape of the die. Occasionally, 

grinding of the bricks to a precise size was required when critical dimensions had to be met (Smith 1945). 

Until 1948, beryllium was machined in the center of a large machine shop located in V Building at the 

Original Technical Area, TA-1, known as V Shop (JHSPH 1999). Flexible exhaust ducts were placed 

near the cutting tool and the captured dust was exhausted into the shop’s atmosphere. Due to the use of 

coarse fiberglass filter media, the Industrial Hygiene Group recommended that the filtered air be 

exhausted outside the shop. 

In 1949, an addition was built onto the main shop where only beryllium would be machined. All 

machines were equipped with local exhaust hoods. Each machine hood was exhausted by a blower-filter 

unit equipped with a wool-felt filter. The air was exhausted outside the building through a common stack. 

The quantity of air exhausted by each unit was approximately 200 ft3

 min-1. In 1951, the concentrations 

of beryllium in stack effluent ranged from 0.1 to 2.0 μg m-3 (JHSPH 1999). 

In 1952, the local exhaust system was enlarged to provide a larger quantity of air for each machine and to 

add an additional lathe and mill to the shop. The blower was capable of exhausting 2,000 ft3

 min-1 through 

the five local exhaust hoods in the shop, thus providing approximately 400 ft3

 min-1 for each hood. A 

cloth tube filter was installed outside the old beryllium machine shop to maximize collection efficiency 

for air cleaning prior to release to the environment. The unit consisted of two steel chambers each 

containing 32 cloth tubes (cotton bags containing asbestos floc as a filter aid) operating continuously with 

a total capacity of 2,000 ft3

 min-1. The collection efficiency determined by isokinetic sampling during 

normal machining operations was 98.8%. The mass median diameter particle size in samples collected 

with a cascade impactor in the duct before the filter was 4 microns (μm) (Mitchell and Hyatt 1957). 

In August 1953, the shop was closed down and all machines and equipment were cleaned to prepare for 

the move to a new shops building at TA-3, SM-39 (JHSPH 1999). Operations in the new beryllium shop 

were started in October 1953 and included two lathes, a mill, a surface grinder, and an index mill used as 
11-6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11

a drill press, all in hood enclosures. The cloth tube filter was moved to the filter room above the machine 

shop in the new building. A dynamic separator was installed before the cloth tube filter and dampers 

were installed on all machine hoods. Orlon bags with no filter aid were used instead of cotton bags with 

asbestos floc. The theoretical collection efficiency increased to 99.9% but the Orlon bags were not as 

effective (Mitchell and Hyatt 1957). 

Continuous stack samples were collected downstream of the dust tube filter in both the old and new 

beryllium shops. Of the 309 samples collected between 1952 and 1956 (44 from the V Shop and 265 from 

the SM-39 Shop), 53% were below 0.05 μg m-3 (the method detection limit), 67% were below 0.10, 77% 

were below 0.2, 94% were below 1.0, 99% were below 2.0, and 100% were below 25 μg m-3. 

Although no tolerance for beryllium stack discharge had been recommended, it was the opinion of the 

Industrial Hygiene Group at that time that the neighborhood tolerance of 0.01 μg m-3 was never exceeded 

based on the results from the exhaust stacks and atmospheric dilution (Mitchell and Hyatt 1957). 

Beryllium work was also initially performed at the Delta, Gamma, I, M, and [old] Sigma buildings at TA1. Work activities at old Sigma included extrusion, welding, heating beryllium in a furnace, and flame 

plating beryllium onto substrates. Beryllium metal was welded and machined at Delta building, and 

beryllium oxide materials were used at M Building. V Shop was a foundry and machine shop where a 

variety of metals, including beryllium were processed (JHSPH 1999) 

As summarized in Table 11-2 and Table 11-3, industrial hygiene records indicate that sampling for 

beryllium has been conducted at numerous buildings at TA-3 and at 19 other Technical Areas. The 

Sigma Complex at TA-3 is made up of three large buildings and several smaller buildings totaling over 

200,000 ft2

. These facilities, built in the 1950s and 1960s, house laboratory areas for materials synthesis, 

and processing, characterization, and fabrication of materials such as beryllium, uranium, thallium, and 

aluminum alloys. The Sigma Complex is home to two groups of the Materials Science and Technology 

Division– Ceramics (MST-4) and Metallurgy (MST-6). 

The three main buildings of the Sigma Complex are: 

• Sigma Building (SM-66)– built in 1959 and 170,000 ft2

 in size; 

• Rolling Mill Building (SM-141)– built in the early 1960s and covering 20,000 ft2

; and 

• Press Building (SM-35)– built in 1953 and 10,000 ft2

 in size. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11 11-7 

Table 11-2. Beryllium operations at TA-3 buildings

Bldg No. Building Name Beryllium Operation 

SM-16 Van de Graaff Lab Sanding 

SM-29 New CMR Bldg chemical synthesis, vaporization, purification 

SM-30 Warehouse Unknown 

SM-39 Shops Bldg machining, milling, brazing, heat treating, cutting 

SM-32 Center for Material Science Unknown 

SM-43 Admin Bldg foils, mirrors, BeO rods 

SM-49 Physics Bldg thin foils 

SM-66 New Sigma Bldg Casting, etching, brazing 

SM-141 Rolling Mill Bldg Coating 

SM-184 Old Occupational Health Lab Unknown 

SM-218 Magnetic Energy and Storage Unknown 

SM-287 Scyllac Bldg Unknown 

 Source: JHSPH 1999. 

Table 11-3. Beryllium operations at Technical Areas other than TA-1 and TA-3

TA No. Technical Area Name Beryllium Operation 

TA-6 Two-Mile Mesa Foils 

TA-8 Anchor Site West storage of BeF and BeO 

TA-9 Anchor Site East BeF fusion furnace 

TA-14 Q Site test firing 

TA-15 R-Site test firing with kg quantities of Be 

TA-16 S-Site laundry, burn pit 

TA-18 Pajarito Site Processing Be-U blocks and BeO rods, ultrasonic cleaning 

TA-21 DP Site Machining, milling, arc melting, palletizing 

TA-33 HP Site Machining using a method X machine 

TA-35 Ten Site high temperature Be salts 

TA-39 Ancho Canyon test firing 

TA-40 DF Site milling, test firing 

TA-41 Icehouse test firing 

TA-46 WA Site Heating 

TA-53 LANSCE targets and beam stops 

TA-11 K Site Unknown 

TA-43 Health Research Lab Unknown 

TA-48 Radiochemistry Unknown 

 Source: JHSPH 1999. 

 BeF = beryllium fluoride; BeO = beryllium oxide; Be-U = beryllium uranium alloy 
11-8 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11

One-third of Sigma Building space contains the mechanical and ventilation equipment necessary to 

protect the health and safety of personnel. The remaining area includes laboratories, offices, and 

administrative areas. The Rolling Mill Building contains laboratories for beryllium processing, powder 

metallurgy, ceramics research and rapid solidification research. The Press Building houses a 5,000-ton 

capacity hydraulic press with a 12-foot maximum opening and laboratories for hazardous materials 

research (LANL 1995). 

Two 1992 files regarding permits for beryllium operations mention historical beryllium cutting operations 

at DP West Site’s Building 5 in the 1960s and possibly 1950s, and existing beryllium operations in Sigma 

building (TA-3-66), TA-16-450, and TA-55-4. The operations at Sigma Building and TA-16-450 had 

existed since the 1950s (Gutierrez 1992, Tiedman 1992). An H-1 Division notebook discusses 

procedures for monitoring beryllium in stack effluent from the CMR Building Wing 5 Filter Tower in 

February 1954 (Enders 1954). 

Dynamic Testing Operations 

Air samples and fallout trays were used to monitor beryllium during explosive tests starting in 1948, 

although beryllium was involved in relatively few tests until 1954 (Voelz and Jordan 1974). Becker and 

Vigil (1999) reviewed the historical beryllium expenditure in dynamic tests conducted by the DX 

Division at LANL, present data on known beryllium concentrations in soil at firing sites, beryllium air 

concentrations measure onsite and beyond LANL boundaries, and beryllium concentrations in swipe 

samples. Records for beryllium use in dynamic testing activities at Los Alamos date back to 1955 and 

include shot records in the form of internal LANL memoranda, DX Division office records and published 

annual beryllium expenditures in LANL Environmental Surveillance reports. It is presumed that 

beryllium was expended in dynamic testing activities before 1955, although there has been no 

compilation of these data. They assumed that 160 kg of beryllium was used prior to 1955, but no 

explanation for this estimate is provided. 

Becker and Vigil (1999) estimated a total beryllium expenditure of 1,064 kg for the period of 1955 

through 1997 (see Table 11-4). Dynamic testing at firing sites is conducted at TA-40, -14, -15, -36, and -

39. The evaluation of available records performed by Becker and Vigil (1999) determined that the 

majority of beryllium expenditure occurred at three firing sites: PHERMEX, E-F, and R-44– all located at 

TA-15. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11 11-9 

Table 11-4. Beryllium expenditure at LANL firing sites 1955-1997

Site Status as of 1999 Beryllium Expended (kg) 

R-44 (TA-15) Closed 346 

PHERMEX (TA-15) Active 332 

E-F Site (TA-15) Closed 321 

R-306 (TA-15) Active 43.6 

All other firing sites at TA-15, -36, -39 -- 21.4 

TOTAL 1,064 

Source: Becker and Vigil 1999. 

Using a mass balance approach and the following assumptions, Becker and Vigil (1999) estimated soil 

concentrations of beryllium for three firing sites. 

• 160 kg of beryllium expended prior to 1955 

• more shots at E-F Site during years prior to 1955 

• 2% of beryllium becomes aerosolized 

• uniform soil concentration to a depth of 6 inches 

The authors of the study found less beryllium in soil than they predicted, so they give possible 

explanations for the discrepancy, such as erosion and non-representative sampling. They postulated that 

the soil sampling might not have been representative of actual onsite contamination, or that other 

processes such as mass movement and erosion removed contamination from the firing sites. 

LANL has conducted open-air dynamic experiments in which weapons components are either detonated 

or impacted against a target, which results in soil contamination with beryllium (Sauer et al. 2001). 

Monthly reports written by the LANL Dynamic Testing Division from December 1975 through 

December 1987 document fugitive emissions from explosive test shots, including quantities of beryllium 

released. During this 13-y period, 178 kg of beryllium were released as a result of test shots conducted at 

TA-15, TA-36 and TA-40. According to the monthly reports, 98% of the total beryllium emissions 

occurred between 1977 and 1982, and in 1984. However, about one-third of the monthly reports for the 

13-y period are missing from the collection identified by the project team, and 75% of the missing reports 

are from the years 1983, 1985, 1986, and 1987. In the reports that are available, 55% of the monthly 

values are reported as 0 kg. The average monthly release is 1.65 kg with a standard deviation of 2.42 kg. 

The median monthly release is 0.02 kg, the 95% upper confidence limit on the mean is 2.04 kg, and the 

maximum monthly release is 10.6 kg (for November 1976). 
11-10 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11

B Building Annex 

LANL Director’s Office Files for 1944 describe a request for four alpha detectors from Chicago for “0.05 

d/cc/s” (disintegrations per cubic centimeter per second) in air in a 14" × 25" duct flowing 800 ft3

 min-1

and in other ducts (Bainbridge 1944). The detector was apparently for B Building annex, which was used 

for testing initiators and was an unmonitored release point for beryllium and polonium. 

Information regarding the former B Building Annex at TA-1 was located in source material for the book 

Critical Assembly (LASL 1944-1945, Hoddeson et al. 2004). A folder in the LANL Archives contains 

draft chapters and LANL memos that were referenced in each chapter and describe the gun device and 

initiator testing. The B-Building annex, called the “wart on B Building,” was authorized by J. Robert 

Oppenheimer and constructed by the end of March 1944. It held a 20-mm, remotely fired, anti-aircraft 

autocannon used for testing scaled-down versions of gun-assembled atomic weapon components such as 

initiators. By mid-April of 1944, the annex was in operation. In August 1944, a “coffin” was authorized 

that was a box that was operated at negative pressure and equipped with a gas mask filter on its exhaust. 

By the end of September, the gun had been used in nearly 180 experiments at a frequency of one per day. 

Chapter 7 in Critical Assembly does not mention beryllium, nor did the assembled memos, as beryllium 

was not viewed as a hazardous material in the early 1940s. About 50 lbs per month of beryllium was 

used in the fabrication of initiators (LASL 1944-1945). 

Quantities of Beryllium Used at Los Alamos 

It has been estimated that 1,064 kg of beryllium was used between 1955 and 1997 and another 160 kg was 

used prior to 1955 at Los Alamos (Becker and Vigil 1999). Ninety-four percent of the beryllium was 

expended at PHERMEX, E-F, and R-44 firing sites and another 4% was expended at firing site R-306. 

Detailed information is not available on the remaining 2%, but it is presumed that it can be divided among 

the other firing sites. 

According to Becker and Vigil (1999), the greatest annual expenditure of beryllium, in excess of 100 kg, 

occurred in 1964 and significant beryllium use occurred between about 1957 and 1971 (see Fig. 11-2). 

Beryllium use since 1985 has been relatively low, with annual expenditures remaining less than 5 kg. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11 11-11 

Fig. 11-2. Annual estimates of beryllium expended in DX-Division dynamic testing operations 

In a 1977 report, LASL scientists estimated that 2% of the beryllium present in test devices becomes 

aerosolized during dynamic experimentation (Dahl and Johnson 1977). Based on this estimate, it has 

been calculated that approximately 1,200 kg of beryllium remains in the soil at Los Alamos and 

approximately 94% or 1,128 kg remains at the E-F, R-44, and PHERMEX firing sites per LANL records. 

Monthly reports written by the LANL M-DO Division document fugitive emissions from explosive test 

shots conducted during from December 1975 to December 1987 (LANL 1975-1987). The emissions data 

are shown in Table 11-5. The release locations are the explosive test areas at TA-15, TA-36 and TA-40. 

Workplace and Environmental Monitoring for Beryllium 

Air concentrations of beryllium have been monitored at LANL for both indoor machining and outdoor 

firing tests operations since 1948 (Voelz 1970). Measures to control beryllium exposure were in place at 

Los Alamos beginning in 1948 based on recommendations from occupational medicine pioneer Dr. 

Harriet Hardy of the Massachusetts Institute of Technology (MIT), who collaborated with the AEC in Los 

Alamos. The Industrial Hygiene Program was introduced at LASL that same year (Mitchell and Hyatt 

1957). 
11-12 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11

Table 11-5. Beryllium released to the environment by shots at TA-15, TA-36, TA-40 

Year Beryllium (kg) Beryllium Oxide (kg) 

1975 0.1 0 

1976 25.54 0 

1977 34.7 3 

1978 29.2 0 

1979 14 0 

1980 9.8 0 

1981 10.6 0 

1982 26 0 

1983 5 0 

1984 16 0 

1985 0 0 

1986 2.1 0 

1987 2 0 

TOTAL 175 3 

 Source: LANL 1975-1987 

 

Beryllium Metal Machining 

The Industrial Hygiene Group at LASL made periodic surveys of beryllium machining operations from 

early 1948 through August 17, 1951. After September 1951, daily air samples were collected whenever 

beryllium was being machined. From September 1951 through 1955, a sampling rate of 20 L min-1 and a 

filtering velocity of 130 ft min-1 with Whatman #41 filter paper resulted in a collection efficiency of 70%. 

In 1956, a sampling rate of 10 L min-1 and a filtering velocity of 65 ft min-1 with Whatman #44 filter 

paper resulted in a theoretical collection efficiency of 99.8% 

A continuous air sampler with a sampling rate of 20 L min-1 and a filtering velocity of 130 ft min-1 using 

Whatman #4 filter paper was used to monitor beryllium air concentrations for short periods of exposure. 

The sampler was set to collect hourly general air samples in the vicinity of the machining operations. The 

reported collection efficiency was 80%. Starting in 1954, the hourly samples were only analyzed when an 

8-h breathing zone sample approached the tolerance level of 25 μg m-3. 

Air samples collected to assess beryllium concentrations through June 1950 were collected with an 

electrostatic precipitator and sent to the University of Rochester for analysis (Mitchell and Hyatt 1957). 

Although air samples were analyzed by the Industrial Hygiene Group beginning in June 1950, samples 

continued to be collected by the electrostatic precipitator through August 1951. Starting in September 

1951, samples were collected using a portable pump connected to a sampling head equipped with filter 

paper. Samples collected after June 1951 were analyzed using a method based on the fluorescence of 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11 11-13 

morin with beryllium in an alkaline solution (Sax and Kramlich ca 1952). Beryllium concentrations 

ranging from 0.05 to 300 μg were adequately detected with this method. It is reported that air samples 

were analyzed by atomic adsorption in the early to mid 1990s, while samples collected in the late 1990s 

were analyzed by inductively coupled plasma atomic emission spectroscopy (Becker and Vigil 1999). 

From 1950 to 1953, filter type respirators were occasionally used on special jobs. In some cases the 

filters from these respirators were analyzed for beryllium content. Analyses of respirator filters used 

during filter unit cleaning, and used during drilling operations without local exhaust ventilation, showed 

beryllium concentrations ranging from 300-400 μg m-3. 

An experiment performed by the Industrial Hygiene Group in 1951 to determine the greatest sources of 

exposure during beryllium operations revealed that rough cutting created the heaviest source of dust. One 

air sample collected in the hood 8 inches from the cutting tool while rough cuts were being made on a 

piece of bar stock yielded a beryllium concentration of 725 μg m-3 (Mitchell and Hyatt 1957). 

Routine air samples collected between September 1957 and June 1958 at the machine shop were well 

below permissible levels (LASL 1957, 1958). A distinct rise in the average beryllium concentration at the 

beryllium shop in 1957 was tracked to full time work on a crash program to make special beryllium 

pieces. The number of air samples collected at CMB-6 was also increased greatly during this time frame 

in association with a research project to determine the best method of joining two pieces of beryllium. 

The beryllium machine shop at Los Alamos was washed down weekly and surface swipe tests were 

performed to ensure that loose beryllium dust levels were maintained below 15 μg ft-2 (Mitchell and Hyatt 

1957) 

Firing Sites 

A 1970 letter report from the LANL Health Division Leader to the Deputy Director of Military 

Application, USAEC, describes the historical air sampling of beryllium near explosive tests at LASL 

from 1948 to 1959 (Voelz 1970). While air samples and fallout trays were used to monitor beryllium 

during explosive tests starting in 1948, beryllium was involved in relatively few tests until 1954. In 1954 

there was beryllium exposure during test firing of beryllium pieces in conjunction with explosives at TA39, the Ancho Canyon Site. Most of the samples were collected between 1956 and 1959 when all tests 

occurred at R Site and were conducted by the GMX-4 group. In 1955, Group W-3 conducted an 

experiment at TA-33 in which a device exploded and large pieces of beryllium were thrown all over the 

firing area. Tests involving beryllium after 1959 were conducted at Ancho Canyon by GMX-6 and at 
11-14 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11

PHERMEX by GMX-11. Table 11-6 summarizes the data described in the 1970 Voelz letter report. The 

letter report also states that a few of the fallout trays “showed beryllium in the collected material” but no 

elaboration is provided. The report concludes, “Because of our experience with these results, shots 

containing beryllium are not monitored regularly but only when some special conditions of testing are 

planned.” 

Table 11-6. Beryllium concentrations measured from LASL explosive tests 1948–1959, μg m-3

Site No. of 

Shots 

No. of 

Samples (N) 

No. of Samples 

>MDC of 0.05 

Maximum 

Onsite 

Maximum 

Offsite 

R-Site 39 156 11 0.66 (0.34) 1 0.05 2 

Ancho Canyon 8 24 1 0.004 3 NR 

PHERMEX 2 NR 0 NR NR 

MDC = minimum detectable concentration; NR = Not reported. 1 Measured 800 y directly downwind from the shot. 2 Measured at Ten Site (TA-35). 3 Measured 150 y from the shot. 

Air sampling for beryllium was performed by the LANL Environmental Surveillance program in the early 

1970s and resumed in the 1990s. Samples collected on the roof of TA-59-1 during 1971 and 1972 

yielded beryllium air concentrations between 0.06 and 0.4 ng m-3 (0.00006 and 0.0004 μg m-3). Quarterly 

samples of airborne beryllium collected onsite, at the Lab perimeter, and regionally in northern New 

Mexico in 1990, 1992, 1993 and 1994 as part of the AIRNET program ranged from 0.002 to 0.061 ng m-3. 

When quarterly sampling was resumed in 1998, quarterly Airnet beryllium values ranged from 0 to 0.1 ng 

m-3. Area air samples collected in 1998 at two firing sites during dynamic shots ranged from 0.013 to 

0.381 μg m-3 of beryllium (Becker and Vigil 1999). 

Beryllium concentrations in surface water samples collected from the E-F Firing Site (TA-15) in March 

1985 ranged from <1 – 2 parts per billion (ppb) in the dissolved fraction, and from 1.2 – 11.5 ppb in the 

suspended fraction. 

The environmental fate of beryllium released from disposal of neutron sources containing beryllium metal 

that cannot be recycled or reused is a research interest of the Off-Site Source Recovery Program at 

LANL. A 2000 progress report describes the experimental use of beryllium-contaminated soils obtained 

from LANL Dynamic Experimentation Division firing sites. Two samples (locations not specified) 

contained 74 and 29 mg kg-1 of beryllium (Sauer et al. 2000). Table 11-7 summarizes the soil data from 

six firing sites (Cokal and Rodgers 1985, Vigil and Becker 1999) 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11 11-15 

Table 11-7. Beryllium concentrations in soil at firing sites, μg g-1

Site Year Samples (n) Range Mean Background 

PHERMEX 1987 59 1 – 470 31.5 1 – 2.4 

PHERMEX 1993 21 <1 – 218 13.4 NR

PHERMEX 1998 18 0.14 – 74 7.1 NR 

E-F 1985 9 2.3 – 14.4 NR NR 

E-F 1999 60 NR 1.3 NR 

R-44, R-45 1994 44 NR 7.2 NR 

TA-39 1995 22 <1.3 – 9.1 NR NR 

TA-40 1995 39 <1.3 NR NR 

 NR = Not Reported 

Aerosolization of beryllium from open-air shots has been studied by groups at LANL (Dahl and Johnson 

1977) and at Lawrence Livermore National laboratory (LLNL) (Shinn et al. 1989). Dahl and Johnson 

(1977) determined that 2% of the beryllium mass became respirable (<10 μm) due to aerosolization. For 

a shot containing 600 g of beryllium, the concentration of beryllium 4,376 y downwind of the shot would 

be 0.2 μg m-3 15-30 min after detonation for 1-3 min. Shinn et al. (1989) found that 8% of the beryllium 

mass became aerosolized, and that the beryllium was largely in the form of insoluble, high-fired 

beryllium oxide. For a shot containing 900 g of beryllium, the concentration of respirable beryllium 55 y 

from the shot was 3.2 μg m-3 for 10 min. However, measured soil concentrations at three LANL firing 

sites were less than predicted assuming 2% or 8% aerosolization (Becker and Vigil 1999), suggesting that 

aerosolization could be greater than 8% (Sauer et al. 2001). 

Beryllium resuspension has been evaluated in three studies, two at LANL and one at Sandia National 

Laboratories. Sandia researchers estimated a resuspension factor of 1×10-7 m-1 for wind blown soil (1 g 

Be per m2

 of soil = 0.1 μg m-3 Be in air) (Luna et al. 1983). A LANL researcher predicted that 

resuspension of beryllium from a firing site could result in worker exposures to 0.6 μg/m3

 of beryllium 

(Maez 1997). However, measured beryllium concentrations during drilling activities at a LANL firing 

site were four orders of magnitude lower (Mroz 1995). 

Episodic Releases 

In a joint effort with the U.S. Air Force, an experiment was performed at Beta Site (TA-5) to evaluate the 

potential air or ground contamination that might result from the burning of a plane containing significant 

amounts of beryllium (LASL 1957) . A piece of beryllium was placed above a large quantity of jet fuel 

and ignited. Air and soil monitoring results failed to reveal detectable quantities of beryllium at a range 

of distances downwind of the fire. 
11-16 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11

Waste Disposal 

Small quantities of beryllium residues were among the chemical waste disposed of in Areas G and L at 

LANL. Waste was disposed of in Areas G and L by emplacement in shafts, trenches and pits excavated in 

the Bandelier Tuff at depths up to 65 ft. In late 1985, 18 boreholes to 100- to 135-ft depths were drilled in 

Bandelier Tuff from the top of Mesita del Buey. Core samples were collected from seven of the 

boreholes at about 10-ft intervals. Only two of 70 samples collected contained concentrations of metals, 

not otherwise specified, were above their detection limits. Both were acquired at shallow depths (20 ft or 

less) at Area L (LANL 1987). All rags and waste from housekeeping activities in the old and new 

beryllium shops were disposed of in the burial pit (Mitchell and Hyatt 1957). 

Off-Site Area Monitoring 

Air samples were collected quarterly between 1990 and 1994 in northern New Mexico, around the 

Laboratory perimeter in Los Alamos, White Rock and Bandelier National Monument, and within the 

Laboratory primarily at TA-52, TA-16 and TA-3 (Becker and Vigil 1999). The mean beryllium 

concentration recorded at the off-site locations during this timeframe was 0.014 ng m-3, while the mean 

concentration reported at the on-site locations was 0.009 ng m-3. Additional sampling was performed at 

off-site and on-site locations in 1998 and the mean air concentration recorded at all sampling locations 

during this year was 0.021 ng m-3. 

Exposure Guidelines for Beryllium 

The U.S. Atomic Energy Commission issued “Recommendations for Control of Beryllium Hazards” in 

August 1951 that included three standards: a 2 μg m-3 in-plant, 8-hr average beryllium concentration; a 25 

μg m-3 beryllium air concentration that can never be exceeded; and a 0.1 μg m-3 monthly average 

concentration at the breathing zone in the neighborhood of a plant handling beryllium (Mitchell and Hyatt 

1957). 

The current OSHA permissable exposure limit (PEL) for occupational exposure to beryllium is 2 μg m-3

(8-h time weighted average). A ceiling limit of 5 μg m-3 must not be exceeded during the work shift, 

except that a 30-min excursion over the ceiling limit is allowed as long as the air concentration never 

exceeds 25 μg m-3 during the 30-min period (NIOSH 2003). 

The current USEPA Reference Concentration (RfC) for beryllium is 0.02 μg/m3

 (USEPA 2009). The RfC 

is an estimate (with uncertainty spanning an order of magnitude) of a daily inhalation exposure of the 

human population (including sensitive subgroups) that is likely to be without an appreciable risk of 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11 11-17 

deleterious effects during a lifetime. The RfC is based on beryllium sensitization and progression to 

chronic beryllium disease (CBD) identified in studies published in 1949 and 1996 (Eisenbud et al. 1949, 

Kreiss et al. 1996). The Kreiss et al. (1996) occupational exposure study identified a LOAEL (Lowest 

Observed Adverse Effect Level) for beryllium sensitization in workers exposed to 0.55 μg m-3 (median of 

average concentrations). A cross-sectional study was conducted of 136/139 of the then-current beryllium 

workers in a plant that made beryllia ceramics from beryllium oxide powder. Measurements from 1981 

and later were reviewed and included area samples, process breathing-zone samples, and personal lapel 

samples (the last year only). The Eisenbud et al. (1949) study, using relatively insensitive screening 

methods, suggests a NOAEL (No Observed Adverse Effect Level) of 0.01-0.1 μg m-3 in community 

residents living near a beryllium plant. The LOAEL from the Kreiss et al. study was used for the 

operational derivation of the RfC because the screening method used in the Eisenbud et al. (1949) study 

was less sensitive than the method used in the Kreiss et al. (1996) study. 

Beryllium Releases and Exposures at Los Alamos 

It has been reported that largest number of men at Los Alamos were exposed during machining of 

beryllium, although the most difficult processes to control involved the use of powdered beryllium and 

soluble beryllium compounds (Hyatt and Milligan 1953). Worker exposure to beryllium from dynamic 

testing was substantially less than that encountered in the machine shop or laboratory settings primarily 

because beryllium was present during detonations conducted outside under atmospheric conditions, and 

because during detonation and afterwards, workers were confined to a closed control bunker or detained 

at road blocks set up 1⁄4 mile or more from the firing site (Becker and Vigil 1999). Post-shot dispersion of 

beryllium particles caused by wind was expected to occur rapidly and to significantly dilute beryllium 

concentrations present in air at the firing sites. If exposures to beryllium did occur at firing sites, it is 

indicated that exposures would have occurred during dust resuspension from soil and vegetation during 

brush removal. 

Secondary occupational exposure of workers’ families significantly increased beryllium intake through 

dust when clothing of occupationally exposed individuals were not kept at the workplace, as was usually 

the case in the 1940s (IPCS 1990). Eisenbud et al. (1949) reported that short-term beryllium levels of 125 

to 2,000 μg m-3 were measured in the indoor air after clothing from employees at a beryllium-producing 

plant were shaken. The authors estimated that approximately 17 μg d-1 could be inhaled by a person 

during the laundering of the same clothing. However, it is documented that Los Alamos provided their 

workers in the machine shop with a provision of complete protective clothing with adequate showering 

facilities (Mitchell and Hyatt 1957). This clothing consisted of coveralls, underwear, socks and safety 
11-18 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11

shoes. Canvas booties were worn over the safety shoes before leaving the machine shop to go to the tool 

crib. Likewise, it has been noted that employees working at firing sites wore dedicated work shoes that 

were removed and remained onsite each evening (Becker and Vigil 1999). 

Medical Surveillance of LANL Workers 

Medical surveillance of workers at LANL began in the 1940s (Stefaniak et al. 2003). A memo from Dr. 

Cleve Beller of LANL dated January 24, 1947 announced that all Sigma Building personnel that handled 

beryllium were examined or had made arrangements to be examined by the Health Group (LASL 1944-

1950). As of completion of a report detailing beryllium use at DX Division Firing Sites (Becker and 

Vigil 1999), it was noted that nine workers in the DX Division were in the beryllium medical surveillance 

program. It was reported that none of these individuals had been identified with chronic beryllium 

disease or beryllium-associated illness. 

An internal memo from Dr. Thomas Shipman of LASL in May 1951 suggests that the health effects 

associated with beryllium were unknown to Los Alamos until November 1947 when Dr. Harriet Hardy of 

MIT held a meeting to discuss beryllium-related health concerns (LASL 1944-1950). The result of this 

meeting was a stoppage of certain beryllium operations (not described) and the use of beryllium at LANL 

was subjected to careful scrutiny from that point forward. 

In a series of memos between Dr. Hardy and Dr. Thomas Shipman, a case of apparent chronic beryllium 

poisoning was discussed (LASL 1944-1950). It was noted that the individual in question worked at Los 

Alamos from 1946 until 1949 for P Division in Building U, which was documented as being in the 

vicinity of the beryllium machining shop. However, this individual’s exposure potential was not limited 

to that alleged at Los Alamos, as he was also employed at other facilities, including Oak Ridge, where 

beryllium was also used. A memo from Dr. Hardy to Dr. Guy Fortney at Oak Ridge in September 1964 

reported that the beryllium content in this individual’s lungs at his time of death was 0.021 μg g-1. Two 

additional cases of apparent berylliosis among LANL personnel were reported in a memo from Dr. 

Shipman in February 1953. 

As of June 1998, 110 workers have been diagnosed with chronic beryllium disease; the majority of these 

workers are associated with the Rocky Flats and Y-12 (Oak Ridge) plants (Becker and Vigil 1999). A 

Former Worker Medical Surveillance Program that included screening for chronic beryllium disease 

(CBD) was started in 1999 (Stefaniak et al. 2003). 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11 11-19 

Beryllium Toxicology and Epidemiology 

Acute beryllium disease is usually observed at relatively high beryllium exposure levels, has a short 

period of induction, and is usually resolved within a couple of months of exposure termination. It is 

believed to be an inflammatory response to beryllium and most regions of the respiratory tract are 

affected; some reported symptoms include nasopharyngitis, shortness of breath, labored breathing, and 

chemical pneumonitis (ATSDR 2002). 

Chronic beryllium disease is a systemic granulomatous disorder that predominantly affects the lungs. In 

general, the occurrence of this disease has been confined to workers exposed to beryllium metal and to 

less soluble beryllium compounds, such as beryllium oxide. However, there have been cases among 

residents living near beryllium manufacturing facilities and in families of workers who wore 

contaminated clothing at home. Chronic beryllium disease is caused by an immune reaction to the 

inhaled beryllium that is deposited in lung airspaces and retained for a prolonged period. In certain 

individuals who become sensitized to beryllium, the beryllium in the lungs binds to protein/peptides in 

the lungs and inflammatory cells accumulate in the lungs. This results in the formation of granuloma and 

the development of fibrosis. Susceptibility to chronic beryllium disease is believed to have a genetic 

component (ATSDR 2002). 

A number of large-scale screening studies have examined beryllium workers and found beryllium 

sensitization rates of 1–15% in workers involved in the production of beryllia ceramics and nuclear 

weapons. More than half of the beryllium sensitized workers were diagnosed with chronic beryllium 

disease. Several studies attempted to establish associations between beryllium sensitization and/or 

chronic beryllium disease and mean, cumulative, and peak exposure levels and duration of employment. 

In general, no consistent associations were found. Although the data are insufficient for establishment of 

concentration-response relationships, the available occupation exposure studies do provide exposure 

levels that may result in beryllium sensitization. Beryllium sensitization and/or chronic beryllium disease 

have been detected at exposure levels of 0.5 μg m-3. Respiratory disease is not likely to occur from 

exposure to beryllium levels in the general environment because ambient air levels of beryllium (0.03–0.2 

ng m-3) are very low (ATSDR 2002). 
11-20 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11

References 

ACGIH. Beryllium and Compounds. Cincinnati, OH: American Conference of Governmental Industrial 

Hygienists; 2006. 

ATSDR. Toxicological Profile for Beryllium. Atlanta, GA: Agency for Toxic Substances and Disease 

Registry, U.S. Department of Health and Human Services 2002. 

Bainbridge KT. Memorandum: Request for Four Alpha Detectors, March 4th, 1944. Los Alamos, NM: 

Los Alamos National Laboratory; 1944. Repos. No. 3314. 

Becker NM, Vigil EA. Beryllium associated with DX Division firing sites. Los Alamos, NM: Los Alamos 

National Laboratory; LA-13645-MS; 1999. Repos. No. 3129. 

Breslin AJ, Harris W, B. Health protection in beryllium facilities; summary of ten years of experience. 

Health and Safety Laboratory. U. S. Atomic Energy Commission; HASL-36; 1958. 

Breslin AJ, Harris WB. Health protection in beryllium facilities; summary of ten years of experience. 

Arch Ind Health 19: 596-648; 1959. 

Cokal EJ, Rodgers JC. Firing Site Project File from LANL Records Center Location F-18-202, TR12210 

Los Alamos, NM: Los Alamos National Laboratory; 1985. Repos. No. 1090. 

Dahl DA, Johnson LJ. Aerosolized Uranium and Beryllium from LASL Dynamic Experiments. Los 

Alamos, NM: Los Alamos National Laboratory; LA-UR-77-681; 1977. Repos. No. 2249. 

Eisenbud MR, Watna RC, Dustan RC, Steadman LC, Harris WB, Wolf BS. Non-occupational berylliosis 

Journal of Industrial Hygiene and Toxicology 31: 282-294; 1949. 

Enders J. Monitoring Notes. OSU 94 Notebook. 1954. Repos. No. 1413. 

Gutierrez RL. Settlement Agreement for the Plutonium Facility (PF-4) Beryllium Notice of Violation Los 

Alamos, NM: Los Alamos National Laboratory; 1992. Repos. No. 1550. 

Hanson C. The Swords of Armageddon. Sunnyvale, CA: CD ROM produced by Chuckelea Publications; 

1995. 

Hardy HL, Tabershaw IR. Delayed chemical pneumonitis occurring in workers exposed to beryllium 

compounds. J. Ind. Hyg. Toxicol. 28: 197-211; 1946. 

Hoddeson L, Henriksen PW, Meade RA, Westfall CL, Baym G, Hewlett R, Kerr A, Penneman R, 

Redman L, Seidel R. Critical Assembly: A Technical History of Los Alamos During the 

Oppenheimer Years, 1943-1945. New ed. Cambridge University Press; 2004. 

HSDB. Beryllium, elemental; Hazardous Substances Data Bank, National Library of Medicine [online]. 

Available at: http://toxnet.nlm.nih.gov. 

Hyatt EC, Milligan MF. Experiences with unusual materials and operations. American Industrial Hygiene 

Association Journal 14: 289-293; 1953. 

Hyslop F, Palmes ED, Alford WC, Monaco AR, Fairhall LT. The toxicology of beryllium. U.S. Public 

Health Service, National Institute of Health Bulletin No. 181; 1943. 

IPCS. Environmental Health Criteria 106 - Beryllium Geneva, Switzerland: International Programme on 

Chemical Safety, World Health Organization; 1990. 

JHSPH. Development of a Medical Screening Program for Former Los Alamos National Laboratory 

Workers - Final Phase I Needs Assessment. Baltimore, MD: Johns Hopkins University School of 

Hygiene and Public Health 1999. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11 11-21 

Kreiss K, Mroz MM, Newman LS. Machining risk of beryllium disease and sensitization with median 

exposures below 2 ug/m3

. American Journal of Industrial Medicine 30: 16-25; 1996. 

LANL. Toxic Releases from Explosives Testing; Data extracted from LANL Division M-DO Monthly 

Reports for December 1975 through December 1987 by LAHDRA analyst Joel Cehn. The source 

documents were located in the LANL Records Center, E-Bay. Row 6, Box 49B. Los Alamos 

National Laboratory. 1975-1987. Repos. No. 2480. 

LANL. Hydrogeologic Assessment of Technical Area 54, Areas G and L. Los Alamos, NM: Los Alamos 

National Laboratory; LAN 1702-SUMM; 1987. Repos. No. 1299. 

LANL. The Sigma Complex: Materials Science and Technology Division. Los Alamos, NM: Los Alamos 

National Laboratory; LALP-94-171; 1995. 

LASL. Memoranda regarding development and testing related to gun-assembled atomic weapons, LANL 

Archives Collection A-1989-092, Folder 13. Memoranda and progress reports. Los Alamos 

Scientific Laboratory. 1944-1945. Repos. Nos. 5403-5418. 

LASL. Workmen Compensation Case Files; Memoranda re: Beryllium Exposure, from LANL Records 

Center Location E-14-8, Cabinet M-2, TR10392, GAMF-8688 Los Alamos, NM: Los Alamos 

Scientific Laboratory; 1944-1950. Repos. No. 2666. 

LASL. H-Division Progress Report, H267 (August 20 - September 20, 1957). Los Alamos, NM: Human 

Studies Team, Los Alamos Scientific Laboratory; HSPT-REL-897; 1957. Repos. No. 2413. 

LASL. H-Division Progress Report, H277 (May 20 - June 20, 1958). Los Alamos, NM: Human Studies 

Project Team, Los Alamos Scientific Laboratory; HSPT-REL-94-904; 1958. Repos. No. 2420. 

Luna R, Parker E, Taylor J. Final Report:YPG dispersal evaluations. Albuquerque, NM: Sandia National 

Laboratories; 1983. Referenced in LA-UR-01-1704 (Sauer et al. 2001). 

Maez L. Beryllium firing site emissions and respirable impacts. Los Alamos,NM: Los Alamos National 

Laboratory; 1997. Cited in LA-UR-01-1704 (Sauer et al. 2001). 

Mitchell RN, Hyatt EC. Beryllium - Hazard Evaluation and Control Covering a Five-Year Study. Los 

Alamos Scientific Laboratory, presented at the American Industrial Hygiene Association 

Meeting. 1957. Repos. No. 1874. 

Mroz G. Measurements of Airborne Be, Pb and U During Drilling Activity at E-F Site; internal 

memorandum to Scott Kinkead of CST-7 dated 31 January 1995. Los Alamos National 

Laboratory. 1995. 

NIOSH. Pocket Guide to Chemical Hazards. Washington, DC: National Institute for Occupational Safety 

and Health, Centers for Disease Control and Prevention, Department of Health and Human 

Services; 2003. 

NRC. Managing Health Effects of Beryllium Exposure. National Academies Press; 2008. 

OSHA. Beryllium and beryllium compounds (Z37.29-1970). Occupational Safety and Health Standards. 

Toxic and Hazardous Substances Z37.29-1970; 2008. 

Sauer NN, Ding M, Ehler DS, Foreman TM, Kazuba JP, Taylor TP. Beryllium Fate and Transport in the 

Environment: Modeling and Experimental Studies. Los Alamos, NM: Los Alamos National 

Laboratory; LA-UR-00-5582; 2000. 

Sauer NN, Ding M, Ehler DS, Foreman TM, Kazuba JP, Taylor TP. Beryllium in the Environment: A 

Review of the Literature and Results from Modeling and Experimental Studies in Support of the 

Off Site source Recovery Program, March 1st, 2001. Los Alamos, NM: Los Alamos National 

Laboratory; LA-UR-01-1704; 2001. 
11-22 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 11

Sax NI, Kramlich W. A Flourophotometric Determination for Beryllium in Microquantities; General 

Electric Data Folder DF 505L100. as cited in Hyatt and Milligan, 1953; ca 1952. 

Shinn JH, Cedarwall RT, Lamson KC, Mitchell CS. Beryllium Dispersion Near Explosive Firing Tables: 

A Comparison of Computed and Observed Results. Livermore, CA: Lawrence Livermore 

National Laboratory; UCID-21682; 1989. 

Smith CS. Los Alamos Technical Report Series, Volume 10 - Metallurgy, Chapter 3 - Beryllium Oxide. 

Los Alamos, NM: Los Alamos Scientific Laboratory; LA-1236; 1945. Repos. No. 1568. 

Stange AW. Beryllium Health Surveillance in U.S. Department of Energy Facilities. IRSST Beryllium 

2005; 2005. 

Stefaniak AB, Weaver VM, Cadorette M, Puckett LG, Schwartz BS, Wiggs LD, Jankowski MD, Breysse 

PN. Summary of the historical beryllium uses and airborne concentration levels at Los Alamos 

National Laboratory. Applied Occupational and Environmental Hygiene 18: 708-715; 2003. 

Tiedman AJ. Permit Applications for Beryllium Processing at LANL. Los Alamos, NM: Los Alamos 

National Laboratory; 1992. Repos. No. 1898. 

USDOE. Chronic Beryllium Disease Prevention Program; Final Rule. 64 CFR 68854; 1999. 

USEPA. Subpart C – National Emission Standard for Beryllium. 40 CFR 61.32(b); 2004. 

USEPA. Integrated Risk Information System, Beryllium and compounds (CASRN 7440-41-7). 2009. 

Van Ordstrand HS, Hughes R, Carmody MG. Chemical pneumonia in workers extracting beryllium 

oxide. Report of three cases. Cleveland Clin. Quart. 10; 1943. 

Vigil EA, Becker NM. Beryllium Associated with DX-Division Firing Sites Los Alamos, NM: Los 

Alamos National Laboratory; LA-13645-MS; 1999. Repos. No. 3129. 

Voelz GM. Letter from G.M. Voelz, Health Division Leader, LASL, to F.R. Tesche, Deputy Director of 

Military Applications, USAEC, regarding Beryllium Sampling at Ancho Canyon for the Period 

1948 to 1959, September 24th, 1970. 1970. Repos. No. 2657. 

Voelz GM, Jordan HS. Effluent monitoring data, 1943-1972. Los Alamos Scientific Laboratory. 1974. 

Weber HH, Engelhardt WE. Application of the research on dusts from beryllium production. Zentrabl. f. 

Gewerbehyg. u. Unfallverhutüng 10: 41-47; 1993. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 12 12-1

Chapter 12: Processing and Testing of High Explosives 

 at Los Alamos 

Research, development, and testing of high explosives were conducted at more than 25 different 

Technical Areas of LANL (Goldie 1984; LANL 1990). Many new formulations of the conventional 

explosives HMX, RDX and TNT were synthesized and tested at LANL since the 1940s (Dobratz 1995). 

Other high explosives such as Baratol, Comp B, Pentolite, Torpex, and Tetryl were tested at firing sites 

such as those at TA-14 (IT Corporation 1989). The initial plan for the first atomic weapon was for a gun 

type weapon that would use “slow-burning” propellants. When it became clear in July 1944 that the 

weapon would have to be an implosion design due to the presence of the 240Pu isotope in the active 

material, high explosives became a key component of the plan. 

X-Division 

The implosion program began in April 1943 with a proposal by S. H. Neddermeyer on an elementary 

theory of high-explosives assembly, but there was no established art to follow. Implosion research started 

as the concern of one small group and grew into the Laboratory’s major problem in the early 1940s. The 

first implosion tests at Los Alamos were made in an arroyo on the mesa just south of the laboratory on 

July 4, 1943. The test device consisted of tamped TNT surrounding steel spheres. In April 1944, G. B. 

Kistiakowsky became the leader for the implosion program. 

Data from photographing the interiors of imploding devices indicated the need for controlled quality of 

high-explosive (HE) castings. Special photographic techniques were developed at LANL to study the 

implosion process, such as rotating pyramid and rotating mirror photography, high-explosive flash 

photography, and flash x-ray photography. The Anchor Ranch range (TA-9) had been designed for 

implosion research, but a large casting plant and several widely spaced test sites were needed. 

Construction of the casting plant was begun in the winter of 1943 at S (Sawmill) Site (TA-16). S-Site was 

staffed almost entirely by men from the Army’s Special Engineering Detachment (SED), because finding 

men with experience in handling explosives was nearly impossible (Hawkins et al. 1961). At the end of 

the war, there were over 1,000 SED men assigned to the X-Division (Kistiakowsky 1975). 

In July 1944, a new development in the implosion program involved the use of explosive lenses that 

would convert a multiple-point detonation into a converging spherical detonation wave thus eliminating 

troublesome interaction. The design of lens molds was a difficult first step and took several months. In the 

August 1944 reorganization, Division X was formed under G. Kistiakowsky to experiment with 
12-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 12

explosives and their fabrication and to set up a production system. Three groups from the old Ordnance 

Division (E-Division) in U Building- Implosion Experimentation, HE Development, and S-Site Group, 

were transferred to the new Explosives (X) Division. Investigation of implosion dynamics and design of 

the active core were given to the Weapon Physics (G) Division (Hawkins et al. 1961). 

Explosives Production and Testing 

X-Division records indicate that about 20,000 experimental quality castings were produced in an 18-

month period, and a much larger number rejected for quality control reasons. The principal types of HE 

used were Composition B, Torpex, Pentolite, Baranol and Baratol. The use of risers and overcasting to 

concentrate imperfections and minimize the very dangerous task of machining HE resulted in over 50,000 

machining operations without a detonation (Hawkins et al. 1961). According to Kistiakowsky (1975), 

tens of thousands of castings were made, primarily of Comp B and Baratol. Baratols, with a higher 

percentage of barium nitrate (76%) than TNT was used for the slow component of the lens system, and 

cyclotols such as Comp B (60% RDX: 40% TNT) were used for the fast component (Kistiakowsky 1975; 

Gibbs and Popolato 1980). 

As described in Wilder (1973), operations at S-Site consisted of melting HE and pouring it into molds 

whose shape was determined by theoretical calculations. The initial facilities at S-Site were inadequate 

especially for machining. As a result, there was continuous planning and construction of new buildings 

until just before the Trinity test in July 1945. Casting operations in Building 42 used stainless steel candy 

kettles, jacketed and steam heated. The molten explosive was poured from the kettle into a rubber bucket 

and then into steel molds. The mold was finished with Cerrotru, a low-melting casting alloy around a 

master shape supported in the steel weldment. In Wilder’s opinion, development of the explosive 

component of the bomb was greatly facilitated by the use of self-adhesive tape just about everywhere. 

Building 27, built in 1945, had larger kettles and the temperature of cooling water could be varied. 

After casting, the HE was taken by hand truck to Building 43 to be machined. The equipment in Building 

43 consisted of one K&T milling machine and several Delta drill presses. Comp B was machined under 

water, and Baratol was initially machined dry but later water was used. Building 55 housed the one small 

high-speed hammer mill used for grinding barium nitrate. Buildings 31, 32 and 33, built in 1945, were 

machining bays for Fosdick radial-arm drills. As S-Site activities expanded, they moved into V-Site (TA25). Three methods were used to protect the cast HE from chipping. Castings were sprayed with the best 

“Bar Top” varnish available, felt was glued to one of two mating surfaces, and blotting paper was glued to 

the sides, in Buildings 519 and 520. Practice assemblies were made in Gamma Building in the main 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 12 12-3

Technical Area. The floors were padded with wrestling mats. The Trinity bomb was assembled in 

Building 516. All explosive operations produced great quantities of scrap that was collected daily and 

burned in the area where Building 260 was located (Wilder 1973). 

According to Hawkins et al. (1961), S-Site at its peak used over 100,000 lbs of high explosives per 

month. G. Kistiakowsky’s recollection was that about 25 tons (50,000 lbs) were trucked up the hill per 

month during the most active HE casting period. X-Division Progress Reports indicate that between 

140,000 and 170,000 lbs per month of high explosives, primarily Comp B, TNT and barium nitrate (BN), 

were used during the months of May, June, July and August 1945 (see Table 12-4). Precision molds and 

machining were required, and according to Kistiakowsky (1975), there were over 500 machinists and 

toolmakers available during the peak period. A full-size casting weighed about 100 lbs, and 1 g of HE 

will reportedly blow off a hand. Kistiakowsky expressed his concerns about using S-Site since five tons 

of HE had to be trucked past Oppenheimer’s office and T-Division every day on its way to S-Site. He 

requested that a new site be established in Pajarito Canyon but his request was denied by Captain Parsons 

(Kistiakowsky 1975). 

L-Site (TA-12, akaTA-67) was constructed in the spring of 1945 and used for one year as an explosives 

test facility, then abandoned in the mid 1950s. Soil tests in 1993 identified RDX, TNT and picric acid at 

the open firing pit and firing pad 1. Q-Site (TA-14) has been used for development and testing of 

explosives since 1944. HMX and metals were identified in Q-site soils [Harris 1993; RCRA Facility 

Investigation plans for OU-1082 (S-Site) and OU-1086 (R-Site)]. 

Sites in the vicinity of TA-16 (S-Site) formerly used in the 1940s for x-ray studies (P and T-Sites) and 

assembly operations (V-Site), and several storage magazines (TA-28, 29, and 37) were decommissioned 

and absorbed into the S-Site complex or are still active. S-Site, K-Site and two of the three magazines 

were still active as of 1994. TA-11 (K-Site) was originally built to study implosion symmetry and was 

more recently used for drop tests to study impact initiation of explosives. The resulting debris in the 

immediate vicinity of the drop tower is picked up and removed for disposal at the TA-16 burning ground. 

These eight sites are the focus of the Remedial Field Investigation for Operable Unit 1082 (LANL 1994). 

Between 1944 and 1948, eight firing sites (A-H) were established at TA-15 (R-Site). Experiments using 

from 50 lbs up to 2 tons of HE were conducted at these firing points. Firing points E and F were the most 

active. Up to 65,000 kg of uranium and 350 kg of beryllium have been expended at these two firing sites. 

Hazardous materials, including uranium, beryllium and lead, have largely been left in place at these sites 

where the materials were deposited by the explosion. Other materials that may have been deposited 
12-4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 12

include steel, aluminum, mercury, boron, cadmium, gold, and tritium reportedly in small amounts. TA-15 

is the focus of the Remedial Field Investigation for Operable Unit 1086 (LANL 1993). 

Other Uses of Explosives at LANL 

During the VJ Day celebration at the Laboratory, Kistiakowsky reportedly borrowed a military jeep with 

a driver and gave the LANL scientists a “21-gun salute” by detonating 21 boxes of Comp B explosive, 

although someone attending the party said there were actually 22 explosions. It was also reported that the 

Pajarito ski hill was cleared of trees using plastic explosives (Kistiakowsky 1975). 

Key Facilities for High Explosives at Los Alamos 

S Site (TA-16) was initially called Sawmill Site, after a portable sawmill that had been erected on the site, 

and left huge piles of sawdust behind. Its name was shortened to S Site. [Martin 1998]. Investigations at 

S Site have included development, engineering design, prototype manufacture, and environmental testing 

of nuclear weapons warhead systems. TA-16 is the site of the Weapons Engineering Tritium Facility for 

tritium handled in glove boxes. Development and testing of high explosives, plastics, and adhesives, and 

research on process development for manufacture of items using these and other materials are 

accomplished in extensive facilities. 

Facilities include a slurry plant with a capacity of 300 lbs of explosive per batch (Cochran et al. 1987). 

The material being cast was a two-phased slurry consisting of a dense solid phase dispersed in molten 

TNT. [Hoddeson et al. 1993] At first Torpex was used, then PTX-2 (Picatinny ternary explosive 2), Comp 

B, Pentolite, Baranol, and Baratol. Earlier operations centered on using high explosives (HE), and 

developing HE lenses to bring about implosion. LANL workers melted HE and poured it into molds 

whose shape was determined by theoretical calculations. Early castings were worked with hand tools, 

saws, rasps, and planes, to a template. HE compounds used included Comp. B, TNT, and Baratol. 

Early explosives processing facilities included: 

• S-24 (possibly a.k.a. TA-16-24) A casting building 

• TA-16-42 Casting (stainless steel candy kettles, jacketed and steam heated, with agitator; 

 HE was poured into a rubber bucket, then to molds) 

• TA-16-43 Machining (K&T milling machine, drill presses, fly cutters. Comp. B was 

 machined under a stream of water. Baratol was initially machined dry because 

 thought water would dissolve the barium nitrate; later machined wet. 

• TA-16-44 Physical inspection (dimensional inspection) 

• TA-16-45 X-ray (portable 150- and 220-keV x-ray machines. Dark room, film processing. 

• TA-16-46 HE storage for X-ray. “Rest House” for castings during dimensional and x-ray 

 inspection. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 12 12-5

• TA-16-48 “gamma-graph” facility (gamma radiography of large or dense objects). 

• TA-16-55 Barium nitrate grinding machinery. 

• TA-16-81 Used to dry nitrocellulose (spread out on trays). 

• TA-16-260 Near the east end of this building was area for daily burning of scrap. Sometimes 

 the material exploded instead of burning. 

• TA-16-27 Built in 1945 to make full-scale castings. 

• 30 thru 34 Built at same time to machine Baratol and Comp. B castings from Building 27. 

• 94 thru 98 Built when it became desirable to machine all surfaces of the HE material. 

• 16-515 thru 520 (called V Site) were under a group other than GMX-3; they had a large 

 mechanical shaker that was used to test the first bomb. The Trinity bomb was 

 assembled in 516. “Active” per 10/2/84 memo from R. Goldie to D. Pinyan; 

 subject was “Areas Containing or Contaminated by Explosives.” “Mechanical 

 Testing” done here per Repository No. 225 (c. 1981) 

Some of the early work being done was considered too dangerous to be performed at TA-1, so these 

operations were placed at remote locations. Alpha Site at TA-4 was used as a firing site for high 

explosives (HE). It was originally used to fire several charges per day of up to 1000 lbs and was then 

converted to accommodate studies of small equation-of-state tests that used only a few pounds of HE per 

shot. Beta Site at TA-5 was used extensively in 1945 as a firing site for the pin or electric method for 

studying implosions. Larger charges could be safely used at TA-5, and shots of several hundred pounds 

were used. S-Site at TA-16 was developed for production of HE to be used in the various tests. [LA-UR97-4765] 

In 1944, a small control building and two firing sites were established at TA-15; one for quantities of HE 

up to 50 lbs and the second for larger amounts. These probably became Firing Sites A and B. Firing Site 

A was probably in use by the end of 1944 and Firing Site B shortly thereafter. In 1946, TA-15 was made 

into a permanent location for explosives experiments related to nuclear weapons design, involving 

experiments with up to 3/4 tons of HE. By 1947, Firing Sites C,D,E, and F were in use. In 1948, E and F 

were designated as one firing site, E-F, and Firing Sites G and H were added. Today, Firing Sites A 

through H are not used, and most structures associated with these firing sites have been decommissioned 

and dismantled. The hazardous materials used in these explosives tests, e.g. U, Be, and Pb, have largely 

been left in place at the firing sites where the materials were deposited by the explosion or pushed aside to 

clean the area. Other materials that may have been deposited in very small amounts include steel, Al, Hg, 

boron, cadmium, gold, and 3

H. Many types of HE were used. While they may have left some residues, 

no unexploded high explosives have been found in the analyses of site soils. Site E-F was most heavily 

used and reportedly contains the largest quantities of hazardous materials. Up to 72 tons of uranium and 

approximately 800 lb of beryllium may have been expended in tests at Firing Site E-F. In the 1950s, 
12-6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 12

Firing Sites R-44 and R-45 were completed. These sites have been used for various explosives tests, R45 for smaller tests and R-44 for larger ones [1086 RFI Report; 10/30/95].

TA-15, “R-Site,” is currently the home of PHERMEX (the pulsed high-energy radiographic machine 

emitting x-rays) a multiple-cavity electron accelerator capable of producing a very large flux of x-rays for 

weapons development testing. It is also the site where DARHT (the dual-axis radiographic hydrotest 

facility) was constructed. This site is also used for the investigation of weapons functioning and systems 

behavior in non-nuclear tests, principally through electronic recordings. 

TA-9, Anchor Site East, housed exploration of fabrication feasibility and physical properties of 

explosives. New organic compounds are investigated for possible use as explosives. Storage and 

stability problems are also studied. Name refers to Anchor Ranch, a small cattle operation that was in the 

area when the MED took it over in 1943. “Active” per 10/2/84 memo from R. Goldie to D. Pinyan; 

subject was “Areas Containing or Contaminated by Explosives.” 

TA-14, Q Site, is a dynamic testing site used for running various tests on relatively small explosive 

charges for fragment impact tests, explosives sensitivities, and thermal responses. “Active” per 10/2/84 

memo from R. Goldie to D. Pinyan; subject was “Areas Containing or Contaminated by Explosives.” 

References 

Cochran et al. 1987. Cochran, T. B., W. M. Arkin, R. S. Norris, M. M. Hoenig. Nuclear Weapons 

Databook Series, Volume III: U.S. Nuclear Warhead Facility Profiles. National Resources Defense 

Council, New York, New York. 1987. 

Dobratz, Brigitta M. The Insensitive High Explosive TATB: Development and characterization-- 1888-

1994. LA-13014-H. LANL Technical Report Library. August 1995. Repos. No. 4994. 

Gibbs, T. R. and A. Popolato 1980. LASL explosive property data. Los Alamos series on dynamic 

material properties. Los Alamos Scientific Laboratory. 

Goldie, R.H. Memorandum from R.H. Goldie, HSE-3, to D. Pinyan, HSE-3. Areas containing or 

contaminated by explosives. October 2, 1984. Repos. No. 658. 

Harris, B. W., D. McRae, J. Powell, and H. Wallace 1993. Report of Field Study at TA-67 (12) L-Site 

and TA-14 Q-Site. Repos. No. 1078. September 1. 

Hawkins et al. 1961. Manhattan District History - Project Y, Vol. Los Alamos Scientific Laboratory. 

Report LAMS-2532 (Vol. I). December 1. 

Hoddeson et al. 1993. Hoddeson, L., P. W. Henriksen, R. A. Meade, and C. Westfall. Critical Assembly 

– A Technical History of Los Alamos during the Oppenheimer Years, 1943-1945. Cambridge University 

Press. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 12 12-7

IT Corporation. Sampling and Analysis Plan for Mixed Waste Surface Disposal Area at TA-14. 1989. 

Repos. No. 2192. 

 

Kistiakowsky 1975. Audio tapes of interviews borrowed from LANL Library. 

LANL 1997. Overview of Los Alamos National Laboratory – 1997. Los Alamos National Laboratory. 

Environment, Safety, and Health. Report LA-UR-97-4765. 

 

LANL 1990. Solid Waste Management Units Report. Environmental Restoration Records Processing 

Facility. November. 

LANL 1992. RFI Work Plan for Operable Unit 1086, Environmental Restoration Program, 1992. Los 

Alamos National Laboratory report LA-UR-92-3968. Repos. No. 4387. December 31. 

LANL 1995. RFI Work Plan for Operable Unit 1082, Environmental Restoration Project, Addendum 2. 

Los Alamos National Laboratory report LA-UR-95-1038. Repos. No. 4361. July 31. 

Martin 1998. Martin, C. Los Alamos Place Names. Los Alamos Historical Society. 
12-8 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 12

This page intentionally left blank.
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 13 13-1

Chapter 13: The LANL Health Division

Although the Health Division at LANL (“H Division”) was responsible for monitoring worker health, 

operations or activities that were associated with potential worker exposures were often also associated 

with potential off-site releases and public health consequences. The LAHDRA project team examined a 

large number of health-related progress reports published by the Health Group, Health Division, and 

successor organizations that carried on programs related to worker and environmental health. This 

chapter provides an overview of the organizational structure of the Health Division and its subgroups 

(such as health physics and industrial hygiene) and describes the various health and safety activities that 

those groups conducted over the years at LANL. A complete listing of the documents issued by the H 

Division and it successor groups that the LAHDRA team has located and selected as relevant to off-site 

releases or health effects is presented as an appendix at the end of this chapter. 

The project team located and reviewed approximately 430 documents that consisted of Health Division 

Progress Reports or reports that are known successors to the Health Division. An example of a successor 

report might be one named under a different title such as Quarterly Progress Report – Group H-1 Health 

Physics. Many division or group reports were published monthly, although quarterly and annual reports 

are available for select years and were also reviewed. The oldest reports available are Health Group and 

Health and Safety reports for 1943 to 1945. In early 1946, Louis H. Hempelmann, MD, then acting 

director of the Health Division, wrote a report titled History of the Health Group (A-6) (March 1943 – 

November 1945). That report discusses issues related to the safe handling of plutonium and polonium and 

monitoring and prevention of worker exposures to these materials. Discussions of hazards associated 

with the RaLa and Omega Site operations as well as other health and safety issues, including injuries, are 

also presented in the report (Hempelmann 1946b). Another early Health Group report titled, Health 

Hazards of LANL Groups by Division, is a compilation of letter reports that provide summaries of early 

operational hazards and health and safety measures used by LANL to control worker exposures 

(Hempelmann 1946a). Many of the groups such as occupational medicine, industrial hygiene, health and 

safety, and health physics remained part of the Health Division up through the 1970s. 

In 1975, the Health Division expanded its name to “Operational Environmental Health and Safety” then 

in 1981 changed it to “Health, Safety, and Environment.” The division has had other name changes since 

that time. Divisional activities continued to be published in progress reports under these and other health 

and safety related division or division group names. 
13-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 13 

History of H Division 

According to the report titled “History of the Health Group,” a directive from the laboratory Director J. 

Robert Oppenheimer, dated 13 November 1943, stated that the medical supervision of technical personnel 

was to be directed primarily at protection of persons from the hazards of the project (Hempelmann 

1946b). The primary function of the Health Group (A-6) at that time was to establish safe tolerance 

levels, develop monitoring methods, and to ensure that tolerance levels were not exceeded for worker 

exposures to hazardous materials. The primary concern was the monitoring and control of workers’ 

exposures to radioactive materials. Preparation of routine monitoring procedures for workers was 

primarily the function of each operational unit or lead individual during this early period. Effluent or 

environmental monitoring that would be of interest for a dose reconstruction study are not mentioned in 

this report. 

The original policy of the Health Group was to depend entirely on information gained from health 

research and development groups elsewhere, such as the “Met. Lab” in Chicago. Because that policy and 

support from outside organizations did not always provide the needed information in time to establish 

safe operating procedures for use at Site Y, research sections were set up within the Health Group, such as 

for development of instrumentation and biological methods for testing for overexposure (Hempelmann 

1946b). For example, approximately half of the 25- to 30-page monthly reports of the era describe 

various areas of research and papers published on the health effects of radiation by H-4, the radiobiology 

group, and instrument development and testing work conducted by the electronic and biophysics sections 

of Radiologic Safety, H-1. Accidents were reported in the Occupational Safety group (H-3) section of the 

division reports. 

On 1 June 1947, the Health Group was renamed the Health Division and Louis H. Hempelmann, MD was 

the Division leader from 1943 until the end of 1948. Thomas L. Shipman, MD, assumed responsibilities 

from Hempelmann in 1948. In 1943, the Health Group consisted of 10 staff and expanded to 97 by 1949; 

by 1951, the group had grown to 158 staff (Hempelmann 1946b, LASL 1950b, 1951) 

Documentation of H-Division Activities 

The reports of the Health Group were typically called Health Reports, and the Division reports were 

called H-Division Progress Reports. The Health Reports are organized in three sections: radiation 

problems, chemical hazards, and general safety. By 1951, the Health Division was divided into six 

groups. Monthly progress reports generally consist of four to seven sections corresponding to the 

operating groups in the division. The six primary groups that operated under the Health Division 

included: 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 13 13-3

• H-1, Administrative and Medical Records later became Radiologic Safety (later renamed H-1 

Health Physics); H-Division administrative activities were reported separately but not given an H 

number; Radiologic Safety included monitoring, electronics, and biophysics sections; 

• H-2, Occupational Health included health physics, industrial hygiene, and occupational 

biochemistry sections; later when Radiologic Safety became a separate group called H-1 Health 

Physics, Occupational Medical was created to maintain responsibility for general clinical 

functions such as physicals and first aid; 

• H-3, Training of Military personnel and Medical staff (LANL employee care) later became 

Occupational Safety and the training function was merged into H-Division Administration; 

• H-4, Radiobiology conducted research on clinical aspects of exposure to chemicals and 

radionuclides including monitoring programs and instrumentation; 

• H-5, Industrial Hygiene and Occupational Biochemistry sections were split off from H-2 and 

formed this group in June 1949; and 

• H-6, Monitoring (CMR-12) was merged into H-1 and then became Radiologic Physics, including 

the old Biophysics group (Special Problems) and the Meteorology section. 

Many of the activities performed by these groups are still being performed today under different 

divisional and/or group names. 

Constructed during 1952-54, the Health Research Laboratory at TA-43 is adjacent to the Los Alamos 

Medical Center in the Los Alamos town site. Research performed at this site has included structural, 

molecular, and cellular radiobiology, biophysics, mammalian radiobiology, mammalian metabolism, 

biochemistry, and genetics. The Department of Energy Los Alamos Area Office is also located within 

TA-43. 

The reference list located at the end of this chapter presents the most up to date list of Health Division 

progress or related group reports that were located and reviewed by the project team. The references are 

grouped by year and title. These reports document and offer insights into LANL’s health and safety 

program and describe health protection philosophies used to monitor personnel, work areas, and loss of 

material to the off-site environment. The list indicates which reports are thought to have been generated 

but for which copies have not been located by the project team as of the writing of this report. Some of 

the missing reports might be missing because a report was not issued for that period, or copies might have 

been lost or filed differently than other reports of the same type. 
13-4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 13 

Groups within the Health Division or from other divisions with health and safety responsibilities also 

published monthly or quarterly progress reports. Relevant information pertaining to off-site emissions 

discovered during document reviews was noted, summarized, and included as appropriate in other 

sections of this report. Below is a list of H (Health) Division and group reports and the years for which 

reports were located and reviewed during the LAHDRA project. This list does not necessarily list reports 

by their exact titles, but rather is intended to provide an overview of the types of health-related reports for 

various periods. The reference list at the end of this chapter does identify relevant reports by their actual 

titles. 

• Health Reports of the LASL Health Division (1943 – 1945) 

• Health Division monthly and quarterly progress reports (1946 – 1972) 

• Summary of Research, Development, and Health Activities in the CMR Division (1944 – 1951) 

• H-1 Monthly Progress/Monitoring Reports DP East and West (1956 – 1966) 

• H-1 General Monitoring Section (1956 – 1964) 

• Airborne Contamination Tests – CMR TA-1 and TA-3 (1952 – 1973) 

• CMR-12 Monthly Reports (1945 – 1950) 

• Air Monitoring Results – DP West (1946 – 1952) 

• Airborne Contamination Tests – DP West/East (1946 -1970) 

• Weekly Reports of Stack Release Data for DP West (1950 – 1956) 

• Monthly and Annual Reports, DP East (1951 – 1955) 

• Health Physics/Radiation Protection quarterly Reports (1973 – 1991) 

• Health, Safety, and Environment quarterly and annual reports (1975 through 1990) 

• Environment, Safety, and Health (1990 – 2005) 

• Environment, Health, Safety, and Quality (2005 – present) 

 

Health Division Perceptions of Hazards at Los Alamos National Laboratory 

In 1943, the hazards of the project were reported to be limited to external radiation from the cyclotron, the 

Van de Graaff, the D-D source, and the radium sources. There were also hazards attributed to uranium 

and the usual chemical laboratory hazards, but these were not serious according to Louis H. Hempelmann. 

Only one accident was noted that occurred during the first year of Site Y operations. It involved 

overexposure to radiation from the cyclotron. The main concern of the Health Group at this time was the 

interpretation of blood counts on exposed personnel to radiation. Normal variation in blood counts was 

not well known at the time (Hempelmann 1946b). 

In February 1944, plutonium arrived at LANL in significant quantities. The members of Chemistry and 

Metallurgy (CM) Division and the Health Group became concerned about the dangers of working with 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 13 13-5

this material. Control of alpha-emitting radioactive materials was described as rather uneventful for the 

first year. After an accident in August 1944 in which a milligram of plutonium blew up in a worker’s 

face, a research program to develop tests for detecting overexposure of personnel with plutonium began. 

A urine test was developed in January 1945 that required a new (free of alpha contamination) laboratory 

(ML Building) to conduct the bioassay tests. Following the first human tracer experiment in April 1945, 

results of the urine tests were evaluated with increased certainty. Until the urine test was perfected, nose 

counts were the only index used to monitor personnel exposures. Due to the difficult and time consuming 

nature of the urine test, the most heavily exposed persons as indicated by nose counts underwent frequent 

urinalyses. Available alpha monitoring equipment lacked both sensitivity and portability, so swipe 

samples were used to detect contamination of hands, nostrils, and workplaces. A proportional counter 

using a methane-filled, thin windowed tube was developed by D. Froman and R. Watts at LANL and 

installed in the D-Building washroom as a hand counter in June 1944 (Hempelmann 1946b). 

In September 1944, the CM-1 group was reorganized and many members of the monitoring and 

decontamination section were transferred to A-6, the Health Group. The new structure did not lead to 

cooperation between the two groups, and in January 1945, H-1 (CM-12), was given full responsibility for 

the entire alpha contamination problem in the CM Division. At that time it was necessary to redesign the 

existing facilities in D Building in order to safely handle the increased amounts of plutonium being 

handled there. In July 1945, CM-5 handled amounts of plutonium that exceeded the capacity of its safety 

equipment, and four persons exceeded the safe amount of one microgram of plutonium in their bodies 

according to urine tests. 

According to Louis Hempelmann, polonium was never the hazard that plutonium was. Because it was 

less radioactive, easier to test in the urine, and relatively simple technical operations were most often 

used, minimal polonium contamination and exposure hazard was recognized. Only two workers 

exceeded the tolerance limit for polonium (1500 counts per minute, “cpm,” in a 24-h urine sample) by 

1946 (Hempelmann 1946b). 

The perceived external radiation hazard at LANL did not change until September 1944, when the Water 

Boiler reactor at Omega Site went into operation. Later, when a higher powered version went into 

operation (January 1945), there were several instances of overexposure when the exhaust line developed 

leaks. There was also an accident that resulted in serious exposure to several chemists during 

decontamination of the active material. By the time of Hempelmann’s 1946 early history summary, there 

had been two serious accidents in critical assembly work at Omega Site, one that overexposed four 

individuals to gamma and neutron radiation, and one fatality. The report does discuss concerns for offsite emissions, monitoring, or control measures (Hempelmann 1946b). 
13-6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 13 

 During the radioactive lanthanum (RaLa) implosion tests that started in September 1944, members of the 

chemistry group CM-4 received periodic overexposures to beta radiation. The toxicity and accepted 

methods for prevention of toxicity from exposure to high explosives were more familiar. In certain cases, 

safe operational procedures were delayed by inadequacies in construction of exhaust systems, washrooms, 

etc., but no serious trouble was encountered between March 1943 and October 1945 according to some H 

Division reports (Hempelmann 1946b). 

Although monthly H-Division reports from 1947 forward repeatedly mention the hazards of beryllium, 

there is no mention of beryllium in Hempelmann (1946b). Table 13-1 presents a summary of materials of 

concern in terms of potential health hazard, based on review of H-Division reports. 

Table 13-1. Materials of Concern from H-Division Reports 

Material of Concern 

(Location of Concern) 

Examples of H-Division Reports 

(LAHDRA Project Repos. Number) 

Arsine 2275, 2392 

Benzol (DP West) 2259, 2266, 2267 

Beryllium (V Shop, Sigma, R-Site, CMR) 2202, 2433, 2434, 2258, 2259, 2262, 

2300, 2224, 2392 

Fluorides (D Building) 2266 

Lithium (Sigma, K) 2270, 2275, 2300, 2301, 2298 

Mercury spills (Omega Site, U-14, K bldg) 2433, 2434, 2211, 2259, 2298 

Polynuclear Aromatic Hydocarbons (scintillation 

fluids) 

2209, 2270, 2275, 2216 

Impurities in RaLa source (Bayo) 2207, 2261, 2262, 2263, 2267, 2268, 2301 

Trichloroethylene (TU, Sandia, Omega, S-Site) 2259, 2260, 2265, 2267, 2201 

TNT (S-Site) 2257, 2433, 2434, 2258, 2260, 2264, 2201 

Thorium 2287, 2383 

Uranium (TU, Sigma, HT) 2257, 2211, 2263, 2216, 2224 

Plutonium 2330, 2375, 7188 

Polonium 124, 3049, 7188 

Incidents Documented in H-Division Reports 

Following are examples of the type of information contained in the monthly H-Division reports. These 

examples come from reports covering a time period of approximately the mid-1950s to the mid-1960s and 

highlight operational conditions at LANL and effluent monitoring activities that are relevant to the 

LAHDRA project. 

Examples of chronic issues or problems cited include: 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 13 13-7

• Liquid waste management problems at Ten Site (TA-35) for the liquid waste streams generated 

by the RaLa program. Problems with plant capacity and equipment lead to several unplanned 

discharges of large volumes of radiostrontium-bearing wastes to Mortandad Canyon. 

• Leakage around improperly installed filtration units site-wide. For example, a report issued on 

the release of alpha activity from DP West stacks in 1955 states “definitely that the CWS-6 filters 

are poorly installed and consistently leak contaminated air around the edges of the filters” 

(Shipman 1955). In 1964, in-place DOP-testing of the filters on top of DP West Building 4 

showed their efficiency to be “approximately 15%” (LASL 1964). 

• Glove box explosions and fires at DP West Site are reported in numerous reports. 

• Emissions of TNT dust from facilities at S Site (TA-16) are reported in numerous reports. 

• Beryllium contamination of soil at R-site (TA-15). The magnitude of the contamination and the 

potential for resuspension prompted remediation activities on several occasions. 

• Unsatisfactory media and methods for sampling airborne effluent streams for radioactive iodine 

due to low and unpredictable collection efficiencies. This was a particular problem for 

quantifying radioiodine releases from Wing 9 of the CMR Building, but it was also an issue at 

Omega Site and DP West Site. 

• Lack of suitable instrumentation and methods for monitoring airborne effluents from the Omega 

Stack, and corresponding uncertainty in assessments of exposure to residents of the old trailer 

court area (most likely the trailer park on DP Road and overlooking Omega Site; see Chapter 15). 

• Lack of appropriate monitoring instrumentation was also a chronic issue at Ten Site, where stack 

effluents during RaLa source preparation activities often could not be assayed due to excessive 

radioactivity. 

• Failures of containment mechanisms for samples being irradiated in the Omega West Reactor. 

For example, such a failure on 7 August 1961 resulted in contamination being found on cars in 

the parking lot and in other areas around the building (LASL 1961b). On 23 December 1963, a 

rather large “sample” was irradiated in the reactor’s vertical port and had to be removed through 

the roof of the building. The sample was then dragged down the road to its storage location. 

Afterward, the roof of the building and the road read 50 mR h-1 and 20 mR h-1, respectively, from 

contamination by 122Sb and 124Sb (Shipman 1964). 

• Soil and groundwater contamination downstream from the TA-35, TA-45, and (in later years) 

TA-50 liquid waste outfalls were reported during the 1950s and 1960s in various reports 
13-8 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 13 

Specific examples of contamination being spread to private property include: 

• A contamination incident at the Water Boiler on 16 August 1950 resulted in contamination being 

spread to a private home (LASL 1950a). 

• In 1961, a 137Cs contamination incident at TA-48 resulted in contamination being tracked off site 

by workers; 28 homes and 47 vehicles were surveyed for contamination (LASL 1961a). 

• 90Sr contamination was spread to a worker’s vehicle on 2 June 1961 from a spill at the H-7 waste 

treatment laboratory (LASL 1961c). 

Specific examples of episodic events and sources of fugitive and unmonitored emissions include: 

• On 8 January 1953, LASL discovered that a polonium-beryllium source had ruptured at the 

Pajarito Site and found that contamination had spread to Los Alamos residential areas. Follow-up 

monitoring was performed to assess the extent of the unmonitored release (Shipman 1953). 

• Dust from the demolition of contaminated buildings in the Original Technical Area (TA-1). 

Demolition activities included Buildings CM, D, HT, J-2, M, ML, and N. Debris from these 

demolition projects was often burned at the contaminated dump site. 

• In 1956, glass vials containing tritium gas were disposed of at Beta Site (TA-5) by placing ten at 

a time in a barrel and dropping a weight on them. At one point, a tritium concentration of 15,000 

μCi m-3 was measured at a distance of 100 ft from the barrel. 

• Unintentional releases of tritium from Building TA-33-86 required the site to be evacuated and 

access restricted by road blocks on multiple occasions (Shipman 1958, 1959b). 

• A nuclear criticality accident at DP West (Building 2) on December 30, 1958 killed one worker 

and exposed numerous others (Shipman 1959a). 

• A fire in a plutonium-contaminated CWS filter at DP West Room 501 on 15 July 1959. Highlycontaminated ash was found both inside and outside the building (Shipman 1959b). Another fire 

occurred in the incinerator drybox exhaust system in DP West Room 313 on 8 December 1959. 

Buildup of residues allowed the fire to spread throughout the exhaust system. It is reported that 

the exhaust stack was red hot up to 5 ft above the roof (LASL 1959). 

• In 1960, hydrogen sulfide emissions from Building TA-46-1 led to complaints from workers 

about fumes being drawn back into the building through the intake air system (Shipman 1960).
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 13 13-9

References 

Hempelmann LH. Health hazards of LASL groups; from LANL Records Center location E-13-25, 

TR6704, Folder 11 Los Alamos Scientific Laboratory. 1946a. Repos. No. 136. 

Hempelmann LH. History of the Health Group (A-6) March 1943 - November 1945; from LANL Records 

Center location E-11-117, TR11921 Los Alamos Scientific Laboratory. 1946b. Repos. No. 978. 

LASL. H-Division Progress Report, July 20, 1950 - August 20, 1950. Los Alamos, NM: Los Alamos 

Scientific Laboratory; 1950a. Repos. No. 2219. 

LASL. H Division Annual Report 1949. Los Alamos, NM: Los Alamos Scientific Laboratory; LA-1072; 

1950b. Repos. No. 2270. 

LASL. H-Division Annual Report, 1950. Los Alamos, NM: Los Alamos Scientific Laboratory; 1951. 

Repos. No. 2224. 

LASL. H-Division Progress Report, November 20, 1959 - December 20, 1959. Los Alamos, NM: Los 

Alamos Scientific Laboratory; 1959. Repos. No. 2494. 

LASL. H Division Monthly Progress Report, April 20, 1961 - May 20, 1961. Los Alamos, NM: Los 

Alamos Scientific Laboratory; 1961a. Repos. No. 2521. 

LASL. H Division Monthly Progress Report, July 20, 1961 - August 20, 1961. Los Alamos, NM: Los 

Alamos Scientific Laboratory; 1961b. Repos. No. 2524. 

LASL. H Division Monthly Progress Report, May 20, 1961 - June 20, 1961 Los Alamos, NM: Los 

Alamos Scientific Laboratory; 1961c. Repos. No. 2522. 

LASL. H-Division Progress Report, July 21, 1964 - August 20, 1964. Los Alamos, NM: Los Alamos 

Scientific Laboratory; 1964. Repos. No. 2507. 

Shipman TL. H Division Monthly Progress Report, December 20, 1952 - January 20, 1953. Los Alamos, 

NM: Los Alamos National Laboratory; 1953. Repos. No. 2276. 

Shipman TL. H Division Monthly Progress Report, H-219, September 20, 1955 - October 20, 1955. Los 

Alamos, NM: Los Alamos National Laboratory; 1955. Repos. No. 2379. 

Shipman TL. H Division Monthly Progress Report, H-279, July 20, 1958 - August 20, 1958. Los Alamos, 

NM: Los Alamos National Laboratory; 1958. Repos. No. 2422. 

Shipman TL. H Division Monthly Progress Report, H-285, December 20, 1958 - January 20, 1959. Los 

Alamos, NM: Los Alamos National Laboratory; 1959a. Repos. No. 2512. 

Shipman TL. H Division Monthly Progress Report, May 20, 1959 - June 20, 1959. Los Alamos, NM: Los 

Alamos National Laboratory; 1959b. Repos. No. 2424. 

Shipman TL. H Division Monthly Progress Report, H-299, August 20, 1960 - September 20, 1960. Los 

Alamos, NM: Los Alamos National Laboratory; 1960. Repos. No. 2429. 

Shipman TL. H Division Monthly Progress Report, December 21, 1963 - January 20, 1964. Los Alamos, 

NM: Los Alamos Scientific Laboratory; 1964. Repos. No. 2812. 
13-10 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 13 

This page intentionally left blank.
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A 13A-1

Appendix 13A: Listing of Reports Issued by the Los Alamos Health Group, Health 

Division, and Successor Groups 

The following compilation of reference documents related to LANL’s Health Division highlights those 

sources of information that contain information relevant to operational activities and effluent monitoring 

practices, particularly for those early operational years when reporting of source term information (i.e., 

basic monitoring data, sampling methods) varied in content both in quantity and quality and are presented 

in a variety of division and group report formats. The reference list is organized chronologically and 

grouped by report titles. 

1943 – 1946 Health Group Reports

Hempelmann, L. H. 1943a – Health Report, LAMS-6, August 9, 1943 Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 7184 

Hempelmann, L. H. 1943b – Health Report, LAMS-10, September 23, 1943 Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 7185 

Hempelmann, L. H. 1943c – Health Report, LAMS-23, November 4, 1943 Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 7186 

Hempelmann, L. H. 1943d – Health Report, LAMS-32, December 9, 1943 Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 7187 

Hempelmann, L. H. 1944a – Health Report, LAMS-46, January 19 1944 Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 2963 

Hempelmann, L. H. 1944b – Health Report, LAMS-67, February 25, 1944 Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 2692 

Hempelmann, L. H. 1944c – Health Report, LAMS-81, April 14, 1944 Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 7188 

Hempelmann, L. H. 1944d – Health Report, LAMS-103, May 31, 1944 Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 7191 

Hempelmann, L. H. 1944e – Health Report, LAMS-126, August 30, 1944 Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 3953 

 

Hempelmann, L. H. 1944f – Health Report, LAMS-157, Month Ending September 30, 1944 Los Alamos Scientific 

Laboratory, Los Alamos, New Mexico. Repos. No. 2257 

Hempelmann, L. H., 1946a, History of the Health Group (A-6), March 1943 – November 1945, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. April 6, 1945. Repos. No. 978 

Hempelmann, L. H., 1946b, Health Hazards of LANL Groups by Division, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 136 
13A-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A

1944 – 1945 Health and Safety Reports

LASL (Los Alamos Scientific Laboratory), 1944a, Health and Safety Report – CM Division LAMS-87, April, 1944, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 7189 

LASL (Los Alamos Scientific Laboratory), 1944b, Health and Safety Report – CM Division LAMS-99, May, 1944, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 7190 

LASL (Los Alamos Scientific Laboratory), 1944b, Health and Safety Report – CM Division LAMS-108, June, 

1944, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 7192 

LASL (Los Alamos Scientific Laboratory), 1944b, Health and Safety Report – CM Division LAMS-129, August, 

1944, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 7193 

LASL (Los Alamos Scientific Laboratory), 1944b, Health and Safety Report – CM Division LAMS-143, 

September, 1944, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 7194 

Steinhardt, R.G., 1945, Summary Report on Health Conditions in RaLa Program, Los Alamos Scientific Laboratory, 

Los Alamos, New Mexico. Repos. No. 6774 

1947 Health Division Reports

LASL (Los Alamos Scientific Laboratory), 1947a, H Division Monthly Progress Report, LAMS-595, May 20, 1947 

- July 20, 1947, HSPT-REL-94-275, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2202 

LASL (Los Alamos Scientific Laboratory), 1947b, H Division Monthly Progress Report, LAMS-610, July 20, 1947 

- August 20, 1947, HSPT-REL-94-310, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2272 

LASL (Los Alamos Scientific Laboratory), 1947c, H Division Monthly Progress Report, LAMS-623, August 20, 

1947 - September 20, 1947, HSPT-REL-94-311, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. 

Repos. No. 2273 

LASL (Los Alamos Scientific Laboratory), 1947d, H Division Monthly Progress Report, LAMS-644, September 20, 

1947 - October 20, 1947, HSPT-REL-94-312, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. 

No. 2274 

LASL (Los Alamos Scientific Laboratory), 1947e, H Division Monthly Progress Report, LAMS-651, October 20, 

1947 - November 20, 1947, HSPT-REL-94-277, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. 

Repos. No. 2204 

LASL (Los Alamos Scientific Laboratory), 1947f, H Division Monthly Progress Report, LAMS-671, November 20, 

1947 - December 20, 1947, HSPT-REL-94-278, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. 

Repos. No. 2205 

LASL (Los Alamos Scientific Laboratory), 1947g, H Division Annual Report 1947, November 24, 1947, HSPTREL-94-276, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2203 

 

1948 Health Division Reports

LASL (Los Alamos Scientific Laboratory), 1948a, H Division Monthly Progress Report, LAMS-687, January 1, 

1948 - February 5, 1948, HSPT-REL-94-279, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. 

No. 2206 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A 13A-3

LASL (Los Alamos Scientific Laboratory), 1948b, H Division Monthly Progress Report, LAMS-700, January 21, 

1948 - February 20, 1948, HSPT-REL-94-280, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. 

Repos. No. 2207 

LASL (Los Alamos Scientific Laboratory), 1948c, H Division Monthly Progress Report, LAMS-716, February 20, 

1948 - March 20, 1948, HSPT-REL-94-281, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. 

No. 2208 

LASL (Los Alamos Scientific Laboratory), 1948d, H Division Monthly Progress Report, LAMS-726, March 21, 

1948 - April 20, 1948, HSPT-REL-94-282, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. 

No. 2209 

LASL (Los Alamos Scientific Laboratory), 1948e, H Division Monthly Progress Report, LAMS-741, April 20, 1948 

- May 20, 1948, HSPT-REL-94-283, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2210 

Note: H Division Monthly Progress Reports for May 20 – June 20, 1948 and June 20 – July 20, 1948 have not been 

located at LANL. 

LASL (Los Alamos Scientific Laboratory), 1948f, H Division Monthly Progress Report, LAMS-783, July 20, 1948 - 

August 20, 1948, HSPT-REL-94-253, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2258 

LASL (Los Alamos Scientific Laboratory), 1948fg H Division Monthly Progress Report, LAMS-790, August 20, 

1948 - September 20, 1948, HSPT-REL-94-254, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. 

Repos. No. 2259 

LASL (Los Alamos Scientific Laboratory), 1948h, H Division Monthly Progress Report, LAMS-803, September 20, 

1948 - October 20, 1948, HSPT-REL-94-257, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. 

No. 2260 

LASL (Los Alamos Scientific Laboratory), 1948i, H Division Monthly Progress Report, October 20, 1948 - 

November 20, 1948, HSPT-REL-94-258, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2261 

LASL (Los Alamos Scientific Laboratory), 1948j, H Division Monthly Progress Report, LAMS 828, November 20, 

1948 - December 20, 1948, HSPT-REL-94-259, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. 

Repos. No. 2262 

Note: An H Division Annual Progress Report for 1948 has not been located at LANL. 

1949 Health Division Reports

LASL (Los Alamos Scientific Laboratory), 1949a, H Division Monthly Progress Report, LAMS 846, December 20, 

1948 - January 20, 1949 HSPT-REL-94-285, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. 

No. 2211 

LASL (Los Alamos Scientific Laboratory), 1949b, H Division Monthly Progress Report, LAMS 805, January 20, 

1949 - February 20, 1949, HSPT-REL-94-302, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. 

Repos. No. 2266 

LASL (Los Alamos Scientific Laboratory), 1949c, H Division Monthly Progress Report, LAMS 877, February 20, 

1949 - March 20 1949, HSPT-REL-94-301, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. 

No. 2265 
13A-4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A

LASL (Los Alamos Scientific Laboratory), 1949d, H Division Monthly Progress Report, LAMS 889, March 20, 

1949 - April 20, 1949, HSPT-REL-94-260, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. 

No. 2263 

LASL (Los Alamos Scientific Laboratory), 1949e, H Division Monthly Progress Report, LAMS 901, April 20, 1949 

- May 20, 1949, HSPT-REL-94-262, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2264 

LASL (Los Alamos Scientific Laboratory), 1949f, H Division Monthly Progress Report, LAMS 917, May 20, 1949 

- June 20, 1949, HSPT-REL-94-264, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2300 

LASL (Los Alamos Scientific Laboratory), 1949g, H Division Monthly Progress Report, LAMS 929, June 20, 1949 

- July 20, 1949, HSPT-REL-94-266, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2301 

LASL (Los Alamos Scientific Laboratory), 1949h, H Division Monthly Progress Report, LAMS 941, July 20, 1949 

- August 20, 1949, HSPT-REL-94-304, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2267 

LASL (Los Alamos Scientific Laboratory), 1949i, H Division Monthly Progress Report, LAMS 956, August 20, 

1949 - September 20, 1949, HSPT-REL-94-306, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. 

Repos. No. 2268 

Note: An H Division Monthly Progress Report for September 20 – October 20, 1949 was not located at LANL. 

LASL (Los Alamos Scientific Laboratory), 1949j, H Division Monthly Progress Report, October 20, 1949 - 

November 20, 1949, HSPT-REL-94-307, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2271 

LASL (Los Alamos Scientific Laboratory), 1949k, Abstract - H Division Monthly Progress Report, November 20, 

1949 - December 20, 1949, HSPT-REL-94-308, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. 

Repos. No. 2269 

Note: An H Division Monthly Progress Report for November 20, 1949 - December 20, 1949 was not located during 

project research activities 

LASL (Los Alamos Scientific Laboratory), 1950a, H Division Annual Report 1949, LA-1072, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2270 

1950 Health Division Reports

Note: An H Division Monthly Progress Report for December 20, 1949 - January 20, 1950 was not located during 

project research activities. 

LASL (Los Alamos Scientific Laboratory), 1950b, H Division Monthly Progress Report, January 20, 1950 - 

February 20, 1950, HSPT-REL-94-302, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2212 

LASL (Los Alamos Scientific Laboratory), 1950c, Abstract, H Division Monthly Progress Report, February 20, 

1950 - March 20, 1950, HSPT-REL-94-287, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. 

No. 2213 

LASL (Los Alamos Scientific Laboratory), 1950d, Abstract, H Division Monthly Progress Report, March 20, 1950 - 

April 20, 1950, HSPT-REL-94-288, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2214 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A 13A-5

LASL (Los Alamos Scientific Laboratory), 1950e, Abstract, H Division Monthly Progress Report, April 20, 1950 - 

May 20, 1950, HSPT-REL-94-289, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2215 

LASL (Los Alamos Scientific Laboratory), 1950f, H Division Monthly Progress Report, May 20 - June 20, 1950, 

HSPT-REL-94-290, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2216 

LASL (Los Alamos Scientific Laboratory), 1950g, H Division Monthly Progress Report, June 20, 1950 - July 20, 

1950, HSPT-REL-94-292, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2218 

LASL (Los Alamos Scientific Laboratory), 1950h, H Division Monthly Progress Report, July 20, 1950 - August 20, 

1950, HSPT-REL-94-294, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2219 

LASL (Los Alamos Scientific Laboratory), 1950i, H Division Monthly Progress Report, August 20, 1950 - 

September 20, 1950, HSPT-REL-94-296, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2220 

LASL (Los Alamos Scientific Laboratory), 1950j, H Division Monthly Progress Report, September 20, 1950 - 

October 20, 1950, HSPT-REL-94-267, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2302 

LASL (Los Alamos Scientific Laboratory), 1950k, H Division Monthly Progress Report, October 20, 1950 - 

November 20, 1950, HSPT-REL-94-270, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2304 

Note: An H Division Monthly progress report for November 20 - December 20, 1950 was not located during project 

research activities. 

LASL (Los Alamos Scientific Laboratory), 1951a, H Division Annual Report 1950, HSPT-REL-94-354, LA-1256, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2224 

1951 Health Division Reports

Note: An H Division Monthly Progress Report for December 20, 1950 - January 20, 1951 was not located during 

project research activities. 

LASL (Los Alamos Scientific Laboratory), 1951b, H Division Monthly Progress Report, January 20, 1951 - 

February 20, 1951, HSPT-REL-94-274, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2201 

LASL (Los Alamos Scientific Laboratory), 1951c, H Division Monthly Progress Report, February 20, 1951 - March 

20, 1951, HSPT-REL-94-298, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2221 

LASL (Los Alamos Scientific Laboratory), 1951d, H Division Monthly Progress Report, March 20, 1951 - April 20, 

1951, HSPT-REL-94-300, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2223 

LASL (Los Alamos Scientific Laboratory), 195e1, H Division Monthly Progress Report, April 20, 1951 - May 20, 

1951, HSPT-REL-94-355, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2225 

LASL (Los Alamos Scientific Laboratory), 1951f, H Division Monthly Progress Report, May 20, 1951 - June 20, 

1951, HSPT-REL-94-357, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2226 

LASL (Los Alamos Scientific Laboratory), 1951g, H Division Monthly Progress Report, June 20, 1951 - July 20, 

1951, HSPT-REL-94-360, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2227 

LASL (Los Alamos Scientific Laboratory), 1951h, H Division Monthly Progress Report, July 20, 1951 - August 20, 

1951, HSPT-REL-94-362, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2228 
13A-6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A

Shipman, T. L., 1951a, H Division Monthly Progress Report, August 20, 1951 - September 20, 1951, HSPT-REL94-326, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2282 

Shipman, T. L., 1951b, H Division Monthly Progress Report, September 20, 1951 - October 20, 1951, HSPT-REL94-327, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2283 

Shipman, T. L., 1951c, H Division Monthly Progress Report, October 20, 1951 - November 20, 1951, HSPT-REL94-329, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2284 

Shipman, T. L., 1951d, H Division Monthly Progress Report, November 20, 1951 - December 20, 1951, HSPTREL-94-330, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2285 

Shipman, T. L., 1952a, H Division Annual Report 1951 HSPT-REL-94-334, LA-1425, Los Alamos Scientific 

Laboratory, Los Alamos, New Mexico. Repos. No. 2287 

1952 Health Division Reports

Shipman, T. L., 1952b, H Division Monthly Progress Report, December, 20, 1951 - January 20, 1952, HSPT-REL94-335, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2288 

Shipman, T. L., 1952c, H Division Monthly Progress Report, January 20, 1952 - February 20, 1952, HSPT-REL-94-

337, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2289 

Shipman, T. L., 1952d, H Division Monthly Progress Report, February 20, 1952 - March 20, 1952, HSPT-REL-94-

338, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2290 

Shipman, T. L., 1952e, H Division Monthly Progress Report, March 20, 1952 - April 20, 1952, HSPT-REL-94-340, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2291 

Shipman, T. L., 1952f, H Division Monthly Progress Report, April 20, 1952 - May 20, 1952, HSPT-REL-94-341, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2292 

Shipman, T. L., 1952g, H Division Monthly Progress Report, May 20, 1952 - June 20, 1952, HSPT-REL-94-344, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2293 

Shipman, T. L., 1952h, H Division Monthly Progress Report, June 20, 1952 - July 20, 1952, HSPT-REL-94-346, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2294 

Shipman, T. L., 1952i, H Division Monthly Progress Report, July 20, 1952 - August 20, 1952, HSPT-REL-94-347, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2295 

Shipman, T. L., 1952j, H Division Monthly Progress Report, August 20, 1952 - September 20, 1952, HSPT-REL94-349, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2296 

Shipman, T. L., 1952k, H Division Monthly Progress Report, September 20, 1952 - October 20, 1952, HSPT-REL94-350, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2297 

Shipman, T. L., 1952l, H Division Monthly Progress Report, October 20, 1952 - November 20, 1952, HSPT-REL94-351, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2298 

Shipman, T. L., 1952m, H Division Monthly Progress Report, November 20, 1952 - December 20, 1952, HSPTREL-94-353, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2299 

Shipman, T. L., 1953a, H Division Annual Report 1952, HSPT-REL-94-313, LA-1538, Los Alamos Scientific 

Laboratory, Los Alamos, New Mexico. Repos. No. 2275 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A 13A-7

1953 Health Division Reports

Shipman, T. L., 1953b, H Division Monthly Progress Report, December 20, 1952 - January 20, 1953, HSPT-REL94-316, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2276 

Shipman, T. L., 1953c, H Division Monthly Progress Report, January 20, 1953 - February 20, 1953, HSPT-REL-94-

318, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2278 

Shipman, T. L., 1953d, H Division Monthly Progress Report, February 20, 1953 - March 20, 1953, HSPT-REL-94-

320, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2279 

LASL (Los Alamos Scientific Laboratory), 1953a, H Division Monthly Progress Report, March 20, 1953 - April 20, 

1953, HSPT-REL-94-322, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2280 

Shipman, T. L., 1953e, H Division Monthly Progress Report, April 20, 1953 - May 20, 1953, HSPT-REL-94-325, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2281 

Shipman, T. L., 1953f, H Division Monthly Progress Report, May 20, 1953 - June 20, 1953, HSPT-REL-94-397, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2327 

Shipman, T. L., 1953g, H Division Monthly Progress Report, June 20, 1953 - July 20, 1953, HSPT-REL-94-398, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2328 

Shipman, T. L., 1953h, H Division Monthly Progress Report, July 20, 1953 - August 20, 1953, HSPT-REL-94-399, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2336 

Shipman, T. L., 1953i, H Division Monthly Progress Report, August 20, 1953 - September 20, 1953, HSPT-REL94-400, H-94A, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2337 

Shipman, T. L., 1953j, H Division Monthly Progress Report, September 20, 1953 - October 20, 1953, HSPT-REL94-401, H-95, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2335 

Shipman, T. L., 1953k, H Division Monthly Progress Report, October 20, 1953 - November 20, 1953, HSPT-REL94-403, H-96 Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2334 

Shipman, T. L., 1953l, H Division Monthly Progress Report, November 20, 1953 - December 20, 1953, HSPT-REL94-404, H-99, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2333 

Shipman, T. L., 1954a, H Division Annual Report 1953, HSPT-REL-94-406, LA-1689, Los Alamos Scientific 

Laboratory, Los Alamos, New Mexico. Repos. No. 2330 

1954 Health Division Reports

Shipman, T. L., 1954b, H Division Monthly Progress Report, H-102, December 20, 1953 - January 20, 1954, HSPTREL-94-405, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2326 

Shipman, T. L., 1954c, H Division Monthly Progress Report, H-110, January 20, 1954 - February 20, 1954, HSPTREL-94-407, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2331 

Shipman, T. L., 1954d, H Division Monthly Progress Report, H-113, February 20, 1954 - March 20, 1954, HSPTREL-94-408, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2332 

Shipman, T. L., 1954e, H Division Monthly Progress Report, H-117, March 20, 1954 - April 20, 1954, HSPT-REL94-409, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2361 
13A-8 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A

Shipman, T. L., 1954f, H Division Monthly Progress Report, H-119, April 20, 1954 - May 20, 1954, HSPT-REL94-410, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2362 

Shipman, T. L., 1954g, H Division Monthly Progress Report, H-120, May 20, 1954 - June 20, 1954, HSPT-REL-94-

412, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2363 

Shipman, T. L., 1954h, H Division Monthly Progress Report, H-122, June 20, 1954 - July 20, 1954, HSPT-REL-94-

413, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2364 

Shipman, T. L., 1954i, H Division Monthly Progress Report, H-200, July 20, 1954 - August 20, 1954, HSPT-REL94-457, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2365 

Shipman, T. L., 1954j, H Division Monthly Progress Report, H-201, August 20, 1954 - September 20, 1954, HSPTREL-94-458, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2366 

Shipman, T. L., 1954k, H Division Monthly Progress Report, H-202, September 20, 1954 - October 20, 1954, 

HSPT-REL-94-459, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2367 

Shipman, T. L., 1954l, H Division Monthly Progress Report, H-204, October 20, 1954 - November 20, 1954, HSPTREL-94-460, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2368 

Shipman, T. L., 1954m, H Division Monthly Progress Report, H-206, November 20, 1954 - December 20, 1954, 

HSPT-REL-94-461, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2369 

Shipman, T. L., 1955a, Annual Report of the Health Division 1954, LA-1888, Los Alamos Scientific Laboratory, 

Los Alamos, New Mexico. Repos. No. 3053 

 

1955 Health Division Reports

Shipman, T. L., 1955b, H Division Monthly Progress Report, H-207, December 20, 1954 - January 20, 1955, HSPTREL-94-462, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2370 

Shipman, T. L., 1955c, H Division Monthly Progress Report, H-208, January 20, 1955 - February 20, 1955, HSPTREL-94-464, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2371 

Shipman, T. L., 1955d, H Division Monthly Progress Report, H-209, February 20, 1955 - March 20, 1955, HSPTREL-94-465, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2372 

Shipman, T. L., 1955e, H Division Monthly Progress Report, H-210, March 20, 1955 - April 20, 1955, HSPT-REL94-466, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2373 

Shipman, T. L., 1955f, H Division Monthly Progress Report, H-212, April 20, 1955 - May 20, 1955, HSPT-REL94-467, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2374 

Shipman, T. L., 1955g, H Division Monthly Progress Report, H-214, May 20, 1955 - June 20, 1955, HSPT-REL-94-

415, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2375 

Shipman, T. L., 1955h, H Division Monthly Progress Report, H-215, June 20, 1955 - July 20, 1955, HSPT-REL-94-

417, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2376 

Shipman, T. L., 1955i, H Division Monthly Progress Report, H-216, July 20, 1955 - August 20, 1955, HSPT-REL94-888, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2377 

Shipman, T. L., 1955j, H Division Monthly Progress Report, H-218, August 20, 1955 - September 20, 1955, HSPTREL-94-889, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2378 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A 13A-9

Shipman, T. L., 1955k, H Division Monthly Progress Report, H-219, September 20, 1955 - October 20, 1955, 

HSPT-REL-94-890, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2379 

Shipman, T. L., 1955l, H Division Monthly Progress Report, H-220, October 20, 1955 - November 20, 1955, HSPTREL-94-891, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2380 

Shipman, T. L., 1955m, H Division Monthly Progress Report, H-223, November 20, 1955 - December 20, 1955, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 4943 

Note: An H Division Annual Progress Report for 1955 was not located during project research activities. 

1956 Health Division Reports

Shipman, T. L., 1956a, H Division Monthly Progress Report, H-225, December 20, 1955 - January 20, 1956, HSPTREL-94-892, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2381 

Shipman, T. L., 1956b, H Division Monthly Progress Report, H-277, January 20, 1956 - February 20, 1956, HSPTREL-94-512, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2382 

Shipman, T. L., 1956c, H Division Monthly Progress Report, H-228, February 20, 1956 - March 20, 1956, HSPTREL-94-513, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2383 

Shipman, T. L., 1956d, H Division Monthly Progress Report, H-230, March 20, 1956 - April 20, 1956, HSPT-REL94-514, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2384 

Shipman, T. L., 1956e, H Division Monthly Progress Report, H-236, April 20, 1956 - May 20, 1956, HSPT-REL94-515, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2385 

Shipman, T. L., 1956f, H Division Monthly Progress Report, H-238, May 20, 1956 - June 20, 1956, HSPT-REL-94-

517, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2386 

Shipman, T. L., 1956g, H Division Monthly Progress Report, H-239, June 20, 1956 - July 20, 1956, HSPT-REL-94-

518, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2387 

Note: An H Division Monthly Progress Report for July 20 – August 20, 1956 was not located during project 

research activities. 

Shipman, T. L., 1956h, H Division Monthly Progress Report, H-241, August 20, 1956 - September 20, 1956, HSPTREL-94-519, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2388 

Shipman, T. L., 1956i, H Division Monthly Progress Report, H-242, September 20, 1956 - October 20, 1956, HSPTREL-94-520, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2389 

Shipman, T. L., 1956j, H Division Monthly Progress Report, H-246, October 20, 1956 - November 20, 1956, HSPTREL-94-521, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2390 

Shipman, T. L., 1956k, H Division Monthly Progress Report, H-249, November 20, 1956 - December 20, 1956, 

HSPT-REL-94-445, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2391 

Note: An H Division Annual Progress Report for 1956 was not located during project research activities. 

1957 Health Division Reports

Shipman, T. L., 1957a, H Division Monthly Progress Report, H-250, December 20, 1956 - January 20, 1957, HSPTREL-94-446, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2488 
13A-10 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A

Shipman, T. L., 1957b, H Division Monthly Progress Report, H-255, January 20, 1957 - February 20, 1957, HSPTREL-94-447, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2393 

Shipman, T. L., 1957c, H Division Monthly Progress Report, H-258, February 20, 1957 - March 20, 1957, HSPTREL-94-893, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2394 

Note: An H Division Monthly Progress Report for March 20 - April 20, 1957 was not located during project 

research activities. 

Shipman, T. L., 1957d, H Division Monthly Progress Report, H-262, April 20, 1957 - May 20, 1957, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 4944 

Shipman, T. L., 1957e, H Division Monthly Progress Report, H-262, May 20, 1957 - June 20, 1957, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 4945 

Shipman, T. L., 1957f, H Division Monthly Progress Report, June 20, 1957 - July 20, 1957, HSPT-REL-94-895; H265, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2411 

Shipman, T. L., 1957g, H Division Monthly Progress Report, H-266, July 20, 1957 - August 20, 1957, HSPT-REL94-896, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2412 

Shipman, T. L., 1957h, H Division Monthly Progress Report, H-267, August 20, 1957 - September 20, 1957, HSPTREL-94-897, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2413 

Shipman, T. L., 1957i, H Division Monthly Progress Report, H-268, September 20, 1957 - October 20, 1957, HSPTREL-94-898, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2414 

Shipman, T. L., 1957j, H Division Monthly Progress Report, H-270, October 20, 1957 - November 20, 1957, HSPTREL-94-449, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2489 

Shipman, T. L., 1957k, H Division Monthly Progress Report, H-271, November 20, 1957 - December 20, 1957, 

HSPT-REL-94-450, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2490 

Shipman, T. L., 1958a, Annual Report, Health Division 1957, HSPT-REL-94-451, LA-,2216 Los Alamos Scientific 

Laboratory, Los Alamos, New Mexico. Repos. No. 2392 

1958 Health Division Reports

Shipman, T. L., 1958b, H Division Monthly Progress Report, H-272, December 20, 1957 - January 20, 1958, HSPTREL-94-899, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2415 

Shipman, T. L., 1958c, H Division Monthly Progress Report, H-273, January 20, 1958 - February 20, 1958, HSPTREL-94-900, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2416 

Shipman, T. L., 1958d, H Division Monthly Progress Report, H-274, February 20, 1958 - March 20, 1958, HSPTREL-94-901, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2417 

Shipman, T. L., 1958e, H Division Monthly Progress Report, H-275, March 20, 1958 - April 20, 1958, HSPT-REL94-902, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2418 

Shipman, T. L., 1958f, H Division Monthly Progress Report, H-276, April 20, 1958 - May 20, 1958, HSPT-REL94-903, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2419 

Shipman, T. L., 1958g, H Division Monthly Progress Report, H-277, May 20, 1958 - June 20, 1958, HSPT-REL-94-

904, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2420 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A 13A-11

Shipman, T. L., 1958h, H Division Monthly Progress Report, H-278, June 20, 1958 - July 20, 1958, HSPT-REL-94-

905, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2421 

Shipman, T. L., 1958i, H Division Monthly Progress Report, H-279, July 20, 1958 - August 20, 1958, HSPT-REL94-906, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2422 

Shipman, T. L., 1958j, H Division Monthly Progress Report, H-282, August 20, 1958 - September 20, 1958, HSPTREL-94-907, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2423 

Shipman, T. L., 1958k, H Division Monthly Progress Report, H-283, September 20, 1958 - October 20, 1958, 

HSPT-REL-94-523, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2509 

Shipman, T. L., 1958l, H Division Monthly Progress Report, H-284, October 20, 1958 - November 20, 1958, HSPTREL-94-525, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2510 

Shipman, T. L., 1958m, H Division Monthly Progress Report, November 20, 1958 - December 20, 1958, HSPTREL-94-527, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2511 

Note: An H Division Annual Progress Report for 1958 was not located during project research activities. 

1959 Health Division Reports

Shipman, T. L., 1959a, H Division Monthly Progress Report, H-285, December 20, 1958 - January 20, 1959, HSPTREL-94-528, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2512 

Shipman, T. L., 1959b, H Division Monthly Progress Report, H-287, January 20, 1959 - February 20, 1959, HSPTREL-94-529, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2513 

Shipman, T. L., 1959c, H Division Monthly Progress Report, February 20, 1959 - March 20, 1959, HSPT-REL-94-

531, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2739 

Shipman, T. L., 1959d, H Division Monthly Progress Report, March 20, 1959 - April 20, 1959, HSPT-REL-94-532, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2514 

Shipman, T. L., 1959e, H Division Monthly Progress Report, April 20, 1959 - May 20, 1959, HSPT-REL-94-534, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2515 

Shipman, T. L., 1959f, H Division Monthly Progress Report, May 20, 1959 - June 20, 1959, HSPT-REL-94-908, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2424 

Shipman, T. L., 1959g, H Division Monthly Progress Report, June 20, 1959 - July 21, 1959, HSPT-REL-94-909, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2425 

Shipman, T. L., 1959h, H Division Monthly Progress Report, July 21, 1959 - August 21, 1959, HSPT-REL-94-911, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2426 

Shipman, T. L., 1959i, H Division Monthly Progress Report, August 20, 1959 - September 20, 1959, HSPT-REL94-912, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2427 

Shipman, T. L., 1959j, H Division Monthly Progress Report, September 20, 1959 - October 20, 1959, HSPT-REL94-482, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2492 

LASL (Los Alamos Scientific Laboratory), 1959a, H Division Monthly Progress Report, October 20, 1959 - 

November 20, 1959, HSPT-REL-94-483, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2493 
13A-12 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A

LASL (Los Alamos Scientific Laboratory), 1959b, H Division Monthly Progress Report, H-295, November 20, 

1959 - December 20, 1959, HSPT-REL-94-486, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. 

Repos. No. 2494 

Note: An H Division Annual Progress Report for 1959 was not located during project research activities. 

1960 Health Division Reports

LASL (Los Alamos Scientific Laboratory), 1960a, H Division Monthly Progress Report, H-296, December 20, 1959 

- January 20, 1960, HSPT-REL-94-487, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2495 

Shipman, T. L., 1960a, H Division Monthly Progress Report, H-297, January 20, 1960 - February 20, 1960, HSPTREL-94-488, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2496 

Shipman, T. L., 1960b, H Division Monthly Progress Report, February 20, 1960 - March 20, 1960, HSPT-REL-94-

491, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2497 

LASL (Los Alamos Scientific Laboratory), 1960b, H Division Monthly Progress Report, H-298, March 20, 1960 - 

April 20, 1960, HSPT-REL-94-492, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2498 

LASL (Los Alamos Scientific Laboratory), 1960c, H Division Monthly Progress Report, April 20, 1960 - May 20, 

1960, HSPT-REL-94-537, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2516 

LASL (Los Alamos Scientific Laboratory), 1960d, H Division Monthly Progress Report, May 20, 1960 - June 20, 

1960, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 4946 

Shipman, T. L., 1960c, H Division Monthly Progress Report, June 20, 1960 - July 20, 1960, HSPT-REL-94-914, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2428 

Shipman, T. L., 1960d, H Division Monthly Progress Report, July 20, 1960 - August 20, 1960, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 4947 

Shipman, T. L., 1960e, H Division Monthly Progress Report, H-299, August 20, 1960 - September 20, 1960, HSPTREL-94-916, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2429 

Shipman, T. L., 1960f, H Division Monthly Progress Report, September 20, 1960 - October 20, 1960, HSPT-REL94-918, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2430 

Shipman, T. L., 1960g, H Division Progress Report, October 20, 1960 - November 20, 1960, Los Alamos Scientific 

Laboratory, Los Alamos, New Mexico. Repos. No. 4948 

Shipman, T. L., 1960h, H Division Monthly Progress Report, November 20, 1960 - December 20, 1960, Los 

Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 4949 

Note: An H Division Annual Progress Report for 1960 was not located during project research activities. 

1961 Health Division Reports

LASL (Los Alamos Scientific Laboratory), 1961a, H Division Monthly Progress Report, December 20, 1960 - 

January 20, 1961, HSPT-REL-94-539, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2517 

LASL (Los Alamos Scientific Laboratory), 1961b, H Division Monthly Progress Report, January 20, 1961 - 

February 20, 1961, HSPT-REL-94-541, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2518 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A 13A-13

LASL (Los Alamos Scientific Laboratory), 1961c, H Division Monthly Progress Report, February 20, 1961 - March 

20, 1961, HSPT-REL-94-542, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2519 

LASL (Los Alamos Scientific Laboratory), 1961d, H Division Monthly Progress Report, March 20, 1961 - April 20, 

1961, HSPT-REL-94-544, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2520 

LASL (Los Alamos Scientific Laboratory), 1961e, H Division Monthly Progress Report, April 20, 1961 - May 20, 

1961, HSPT-REL-94-546, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2521 

LASL (Los Alamos Scientific Laboratory), 1961f, H Division Monthly Progress Report, May 20, 1961 - June 20, 

1961, HSPT-REL-94-548, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2522 

LASL (Los Alamos Scientific Laboratory), 1961g, H Division Monthly Progress Report, June 20, 1961 - July 20, 

1961, HSPT-REL-94-549, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2523 

LASL (Los Alamos Scientific Laboratory), 1961h, H Division Monthly Progress Report, July 20, 1961 - August 20, 

1961, HSPT-REL-94-551, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2524 

LASL (Los Alamos Scientific Laboratory), 1961i, H Division Monthly Progress Report, August 20, 1961 - 

September 20, 1961, HSPT-REL-94-552, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2525 

LASL (Los Alamos Scientific Laboratory), 1961j, H Division Monthly Progress Report, September 20, 1961 - 

October 20, 1961, HSPT-REL-94-553, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2813 

LASL (Los Alamos Scientific Laboratory), 1961k, H Division Monthly Progress Report, October 21, 1961 - 

November 20, 1961, File # 00131187 Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

4950 

LASL (Los Alamos Scientific Laboratory), 1961l H Division Monthly Progress Report, November 21, 1961 - 

December 20, 1961, HSPT-REL-94-554, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2526 

Note: An H Division Annual Progress Report for 1961 was not located during project research activities. 

1962 Health Division Reports

LASL (Los Alamos Scientific Laboratory), 1962a, H Division Monthly Progress Report, December 21, 1961 - 

January 20, 1962, HSPT-REL-94-555, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2527 

LASL (Los Alamos Scientific Laboratory), 1962b, H Division Monthly Progress Report, January 21, 1962 - 

February 20, 1962, HSPT-REL-94-556, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2528 

LASL (Los Alamos Scientific Laboratory), 1962c, H Division Monthly Progress Report, February 21, 1962 - March 

20, 1962, HSPT-REL-94-595, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2529 

LASL (Los Alamos Scientific Laboratory), 1962d, H Division Monthly Progress Report, March 21, 1962 - April 20, 

1962, HSPT-REL-94-596, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2530 

LASL (Los Alamos Scientific Laboratory), 1962e, H Division Monthly Progress Report, April 21, 1962 - May 20, 

1962, HSPT-REL-94-597, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2531 
13A-14 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A

LASL (Los Alamos Scientific Laboratory), 1962f, H Division Monthly Progress Report, May 21, 1962 - June 20, 

1962, HSPT-REL-94-598, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2532 

Note: An H Division Monthly Progress Report for June 21 - July 20, 1962 was not located during project research 

activities. 

Stoll, R. D., 1962, H Division Monthly Progress Report, July 21, 1962 - August 20, 1962, HSPT-REL-94-599, Los 

Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2533 

LASL (Los Alamos Scientific Laboratory), 1962g, H Division Monthly Progress Report, August 21, 1962 - 

September 20, 1962, HSPT-REL-94-600, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2534 

LASL (Los Alamos Scientific Laboratory), 1962h, H Division Monthly Progress Report, September 21, 1962 - 

October 20, 1962, HSPT-REL-94-601, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2535 

Note: An H Division Monthly Progress Report for October 21 - November 20, 1962 was not located during project 

research activities. 

LASL (Los Alamos Scientific Laboratory), 1962i, H Division Monthly Progress Report, November 21, 1962 - 

December 20, 1962, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 4951 

 

Note: An H Division Annual Progress Report for 1962 was not located during project research activities. 

1963 Health Division Reports

LASL (Los Alamos Scientific Laboratory), 1963a, H Division Monthly Progress Report, December 21, 1962 - 

January 20, 1963, HSPT-REL-94-499, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2499 

LASL (Los Alamos Scientific Laboratory), 1963b, H Division Monthly Progress Report, January 21, 1963 - 

February 20, 1963, HSPT-REL-94-500, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2500 

LASL (Los Alamos Scientific Laboratory), 1963c, H Division Monthly Progress Report, February 21, 1963 - March 

20, 1963, HSPT-REL-94-501, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2501 

Shipman, T. L., 1963a, H Division Monthly Progress Report, March 21, 1963 - April 20, 1963, HSPT-REL-94-602, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2536 

Shipman, T. L., 1963b, H Division Monthly Progress Report, April 21, 1963 - May 20, 1963, HSPT-REL-94-603, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2537 

Shipman, T. L., 1963c, H Division Monthly Progress Report, May 21, 1963 - June 20, 1963, HSPT-REL-94-604, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2538 

Shipman, T. L., 1963d, H Division Monthly Progress Report, June 21, 1963 - July 20, 1963, HSPT-REL-94-605, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2539 

Stoll, R. D., 1963, H Division Monthly Progress Report, July 21, 1963 - August 20, 1963, HSPT-REL-94-607, Los 

Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2540 

LASL (Los Alamos Scientific Laboratory), 1963d, H Division Monthly Progress Report, August 21, 1963 - 

September 20, 1963, HSPT-REL-94-608, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2541 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A 13A-15

Note: An H-Division Progress Report for September 21 - October 20, 1963 was not located during project research 

activities. 

LASL (Los Alamos Scientific Laboratory), 1963e, H Division Monthly Progress Report, October 21, 1963 - 

November 20, 1963, HSPT-REL-94-502, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2502 

LASL (Los Alamos Scientific Laboratory), 1963f, H Division Monthly Progress Report, November 21, 1963 - 

December 20, 1963, HSPT-REL-94-503, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2503 

Note: An H Division Annual Progress Report for 1963 was not located during project research activities. 

1964 Health Division Reports

Shipman, T. L., 1964, H Division Monthly Progress Report, December 21, 1963 - January 20, 1964, HSPT-REL-94-

609, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2812 

Note: An H Division Monthly Progress Report for January 21 – February 20, 1964 was not located during project 

research activities. 

LASL (Los Alamos Scientific Laboratory), 1964a, H Division/Group H-1 Monthly Progress Report (memorandum 

from M.A. Frechette to D.D. Meyer), January 21, 1964 - February 20, 1964, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 4529. 

LASL (Los Alamos Scientific Laboratory), 1964b, H Division Monthly Progress Report, February 21, 1964 - March 

20, 1964, HSPT-REL-94-504, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2504 

Note: An H Division Monthly Progress Report for March 21 - April 20, 1964 was not located during project 

research activities. 

LASL (Los Alamos Scientific Laboratory), 1964c, H Division Monthly Progress Report, April 21, 1964 - May 20, 

1964, HSPT-REL-94-505, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2505 

Note: An H Division Monthly Progress Report for May 21 - June 20, 1964 was not located during project research 

activities. 

LASL (Los Alamos Scientific Laboratory), 1964d, H Division/Group H-1 Monthly Progress Report (memorandum 

from D.A. McKown to D.D. Meyer), May 21, 1964 - June 19, 1964, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 4529. 

LASL (Los Alamos Scientific Laboratory), 1964e, H Division Monthly Progress Report, June 21, 1964 - July 20, 

1964, HSPT-REL-94-507, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2506 

LASL (Los Alamos Scientific Laboratory), 1964f, H Division/Group H-1 Monthly Progress Report (memorandum 

from M.F. Dean to D.D. Meyer), June 20, 1964 – July 20, 1964, Los Alamos Scientific Laboratory, Los Alamos, 

New Mexico. Repos. No. 4529 

LASL (Los Alamos Scientific Laboratory), 1964g, H Division Monthly Progress Report, July 21, 1964 - August 21, 

1964, HSPT-REL-94-508, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2507 

LASL (Los Alamos Scientific Laboratory), 1964h, H Division Monthly Progress Report, August 21, 1964 - 

September 20, 1964, HSPT-REL-94-509, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

2508 
13A-16 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A

Note: An H Division Monthly Progress Report for September 21 - October 20, 1964 was not located during project 

research activities. 

LASL (Los Alamos Scientific Laboratory), 1964i, H Division/Group H-1 Monthly Progress Report (memorandum 

from D.E. Hankins to D.D. Meyer), September 21, 1964 – October 20, 1964, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 4529 

LASL (Los Alamos Scientific Laboratory), 1964j, H Division/Group H-1 Monthly Progress Report (memorandum 

from J.E. Dummer to D.D. Meyer), October 21, 1964 – November 20, 1964, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 4529 

Note: H Division Monthly Progress Reports for October 21 - November 20, 1964 and November 21, 1964 – 

December 20, 1964 were not located during project research activities. 

Note: An H Division Annual Progress Report for 1964 was not located during project research activities. 

1965 Health Division Reports

LASL (Los Alamos Scientific Laboratory), 1965a, H Division Monthly/Quarterly Progress Report, January - March, 

1965. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No.6262. 

LASL (Los Alamos Scientific Laboratory), 1965b, H Division Monthly/Quarterly Progress Report, April - June 

1965. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6263. 

LASL (Los Alamos Scientific Laboratory), 1965c, H Division Monthly/Quarterly Progress Report, July -September, 

1965. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6264. 

LASL (Los Alamos Scientific Laboratory), 1965d, H Division Monthly/Quarterly Progress Report, October - 

December, 1965. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6265. 

1966 Health Division Reports

LASL (Los Alamos Scientific Laboratory), 1966a, H Division Monthly/Quarterly Progress Report, January - March, 

1966. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6266. 

LASL (Los Alamos Scientific Laboratory), 1966b, H Division Monthly/Quarterly Progress Report, April - June 

1966. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6267. 

LASL (Los Alamos Scientific Laboratory), 1966c, H Division Monthly/Quarterly Progress Report, July -September, 

1966. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6268 

LASL (Los Alamos Scientific Laboratory), 1966d, H Division Monthly/Quarterly Progress Report, October - 

December, 1966. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6269. 

1967 Health Division Reports

LASL (Los Alamos Scientific Laboratory), 1967a, H Division Monthly/Quarterly Progress Report, January - March, 

1967. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6270. 

LASL (Los Alamos Scientific Laboratory), 1967b, H Division Monthly/Quarterly Progress Report, April - June 

1967. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6271. 

LASL (Los Alamos Scientific Laboratory), 1967c, H Division Monthly/Quarterly Progress Report, July -September, 

1967. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6272 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A 13A-17

LASL (Los Alamos Scientific Laboratory), 1967d, H Division Monthly/Quarterly Progress Report, October - 

December, 1967. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6273. 

1968 Health Division Reports

LASL (Los Alamos Scientific Laboratory), 1968a, H Division Monthly/Quarterly Progress Report, January - March, 

1968. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6274. 

LASL (Los Alamos Scientific Laboratory), 1968b, H Division Monthly/Quarterly Progress Report, April - June 

1968. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. 6275. 

LASL (Los Alamos Scientific Laboratory), 1968b, H Division Monthly/Quarterly Progress Report, July - Spetember 

1968. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. 817. 

LASL (Los Alamos Scientific Laboratory), 1968c, H Division Monthly/Quarterly Progress Report, October - 

December, 1968. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6276. 

1969 Health Division Reports

LASL (Los Alamos Scientific Laboratory), 1969a, H Division Monthly/Quarterly Progress Report, January - March, 

1969. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6277. 

LASL (Los Alamos Scientific Laboratory), 1969b, H Division Monthly/Quarterly Progress Report, April - June 

1969. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6278. 

LASL (Los Alamos Scientific Laboratory), 1969c, H Division Monthly/Quarterly Progress Report, July -September, 

1969. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6279. 

LASL (Los Alamos Scientific Laboratory), 1969d, H Division Monthly/Quarterly Progress Report, October - 

December, 1969. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. Nos. 4182 and 6280. 

1970 Health Division Reports

LASL (Los Alamos Scientific Laboratory), 1970a, H Division Monthly/Quarterly Progress Report, January - March, 

1970. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6281. 

LASL (Los Alamos Scientific Laboratory), 1970b, H Division Monthly/Quarterly Progress Report, April - June 

1970. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6282. 

LASL (Los Alamos Scientific Laboratory), 1970c, H Division Monthly/Quarterly Progress Report, July -September, 

1970. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6283. 

Note: Monthly or quarterly H Division Progress reports for the period October - December, 1970 were not located 

during project research activities. 

1971 Health Division Reports

Voelz, G. L., 1971a, H Division Progress Report, January - March 1971, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 4704 

Voelz, G. L., 1971b, H Division Progress Report, April - June 1971, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 4705 

Voelz, G. L., 1971c, H Division Progress Report, July - September 1971, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 4878 
13A-18 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A

Voelz, G. L., 1972a, H Division Progress Report, October - December 1971, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 4991 

1972 Health Division Reports

Voelz, G. L., 1972b, H Division Progress Report, January - March 1972, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 4992 

Voelz, G. L., 1972c, H Division Progress Report, April - June 1972, Los Alamos Scientific Laboratory, Los Alamos, 

New Mexico. Repos. No. 4990 

Note: Quarterly Progress Reports for July – September 1972 and October – December 1972 was not located during 

project research activities. 

1973 and 1974 Health Division Reports

Note: H-Division Quarterly Progress Reports from third quarter of 1972 through 1980 were not located during the 

project. Quarterly reports were located for 1981 and second quarter 1982. Additional H-Division reports for this 

time period and later were not located during project research activities. 

1981 Health Division Reports

LASL (Los Alamos Scientific Laboratory), 1981b, Health Division Quarterly Report, January - March 1981, Los 

Alamos National Laboratory, Los Alamos, New Mexico. Repos. No. 936 

LASL (Los Alamos Scientific Laboratory), 1981c, Health Division Quarterly Report, April - June 1981, Los Alamos 

National Laboratory, Los Alamos, New Mexico. Repos. No. 936 

LASL (Los Alamos Scientific Laboratory), 1981d, Health Division Quarterly Report, July - September 1981; Los 

Alamos National Laboratory, Los Alamos, New Mexico. Repos. No. 5603 

LASL (Los Alamos Scientific Laboratory), 1981e, Health Division Quarterly Report, October - December 1981, 

Los Alamos National Laboratory, Los Alamos, New Mexico. Repos. No. 935 

1982 Health Division Reports

LANL (Los Alamos National Laboratory), 1982, Health Division Quarterly Report, April – June 1982, Los Alamos 

National Laboratory, Los Alamos, New Mexico. Repos. No. 3689 

Note: Quarterly Progress Reports for January – March, 1981 and July – December, 1981 were not located during 

project research activities. 

Note: Starting the third quarter of 1972, LASL began to publish quarterly and monthly Health Physics reports. 

1972 Health Physics Reports

Meyer D.D. 1972a. Quarterly Progress Report – Group H-1 Health Physics, July – September 1972, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 4985. 

Meyer D.D. 1972b. Quarterly Progress Report – Group H-1 Health Physics, October - December 1972, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. 4986. 

1973 Health Physics Reports

Meyer D.D. 1972b. Quarterly Progress Report – Group H-1 Health Physics, January – March 1973, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 4987. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A 13A-19

Meyer D.D. 1972b. Quarterly Progress Report – Group H-1 Health Physics, April – June 1973, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 4988. 

Valentine, A., 1973, Quarterly Progress Report for October – December, 1973 for Operational Health Physics, Los 

Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5453. 

1975 Health Physics Reports

Dummer, J.E., 1975a, Quarterly Progress Report – Group H-1 Health Physics, July – September 1975, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392a 

Dummer, J.E., 1975b, Quarterly Progress Report – Group H-1 Health Physics, October - December 1975, Los 

Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 448 

1976 Health Physics Reports

Dummer, J.E., 1977a, Quarterly Progress Report – Group H-1 Health Physics, January - March 1977, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392b 

Dummer, J.E., 1977b, Quarterly Progress Report – Group H-1 Health Physics, April - June 1977, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392c 

Dummer, J.E., 1977c, Quarterly Progress Report – Group H-1 Health Physics, July - September 1977, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392d 

Dummer, J.E., 1977d, Quarterly Progress Report – Group H-1 Health Physics, October - December 1977, Los 

Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392e 

1977 Health Physics Reports

Dummer, J.E., 1977a, Quarterly Progress Report – Group H-1 Health Physics, January - March 1977, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392b 

Dummer, J.E., 1977b, Quarterly Progress Report – Group H-1 Health Physics, April - June 1977, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392c 

Dummer, J.E., 1977c, Quarterly Progress Report – Group H-1 Health Physics, July - September 1977, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392d 

Dummer, J.E., 1977d, Quarterly Progress Report – Group H-1 Health Physics, October - December 1977, Los 

Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392e 

Note: Starting in the third quarter of 1978, Area Heath Physics (Group H-1) began reporting activities in separate 

monthly and quarterly reports. The last report with these titles that were located during the project is for January 

1981 activities. 

1978 Health Physics Reports

Dummer, J.E., 1978a, Quarterly Progress Report – Group H-1 Health Physics, January - March 1978, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392f 

Dummer, J.E., 1978b, Quarterly Progress Report – Group H-1 Health Physics, April - June 1978, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392g 

Dummer, J.E., 1978c, Quarterly Progress Report – Group H-1 Health Physics, July - September 1978, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392h 
13A-20 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A

Dummer, J.E., 1978d, Quarterly Progress Report – Group H-1 Health Physics, October - December 1978, Los 

Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392i 

Note: Starting in the third quarter of 1978, Area Heath Physics began reporting activities in separate monthly and 

quarterly reports. 

Dummer, J.E., 1978e, Area Health Physics Monthly Report, July 1978, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5470 

Dummer, J.E., 1978f, Area Health Physics Monthly Report, August 1978, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5560 

Dummer, J.E., 1978g, Area Health Physics Monthly Report, September 1978, Los Alamos Scientific Laboratory, 

Los Alamos, New Mexico. Repos. No. 5561 

Dummer, J.E., 1978h, Area Health Physics Monthly Report, October 1978, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5562 

Dummer, J.E., 1978i, Area Health Physics Monthly Report, November 1978, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5563 

Dummer, J.E., 1978j, Area Health Physics Monthly Report, December 1978, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5583 

1979 Health Physics Reports

Dummer, J.E., 1979a, Quarterly Progress Report – Group H-1 Health Physics, January - March 1979, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392j 

Dummer, J.E., 1979b, Quarterly Progress Report – Group H-1 Health Physics, April - June 1979, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392k 

Dummer, J.E., 1979c, Quarterly Progress Report – Group H-1 Health Physics, July - September 1979, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392l 

Dummer, J.E., 1979d, Quarterly Progress Report – Group H-1 Health Physics, October - December 1979, Los 

Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392m. 

Dummer, J.E., 1979e, Area Health Physics Monthly Report, January 1979, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5473 

Dummer, J.E., 1979f, Area Health Physics Monthly Report, February 1979, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. 5474 

Dummer, J.E., 1979g, Area Health Physics Monthly Report, March 1979, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5475 

Dummer, J.E., 1979h, Area Health Physics Monthly Report, April 1979, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5476 

Dummer, J.E., 1979i, Area Health Physics Monthly Report, May 1979, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5477 

Dummer, J.E., 1979j, Area Health Physics Monthly Report, June 1979, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5478 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A 13A-21

Dummer, J.E., 1979k, Area Health Physics Monthly Report, July 1979, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5479 

Dummer, J.E., 1979l, Area Health Physics Monthly Report, August 1979, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5480 

Dummer, J.E., 1979m, Area Health Physics Monthly Report, September 1979, Los Alamos Scientific Laboratory, 

Los Alamos, New Mexico. Repos. No. 5481 

Dummer, J.E., 1979n, Area Health Physics Monthly Report, October 1979, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5566 

Dummer, J.E., 1979o, Area Health Physics Monthly Report, November 1979, Los Alamos Scientific Laboratory, 

Los Alamos, New Mexico. Repos. No. 5568 

Dummer, J.E., 1980a, Area Health Physics Monthly Report, December 1979, Los Alamos Scientific Laboratory, 

Los Alamos, New Mexico. Repos. No. 5567 

1980 Health Physics Reports

Dummer, J.E., 1980a, Quarterly Progress Report – Group H-1 Health Physics, January - March 1980, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392n 

Dummer, J.E., 1980b, Quarterly Progress Report – Group H-1 Health Physics, April - June 1980, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392o 

Dummer, J.E., 1980c, Quarterly Progress Report – Group H-1 Health Physics, July - September 1980, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392p 

Dummer, J.E., 1980d, Quarterly Progress Report – Group H-1 Health Physics, October - December 1980, Los 

Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392q 

Note: Starting in the third quarter of 1978, Area Heath Physics began reporting activities in separate monthly 

reports. 

Dummer, J.E., 1980e, Area Health Physics Monthly Report, January 1980, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5569 

Dummer, J.E., 1980f, Area Health Physics Monthly Report, February 1980, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5570 

Dummer, J.E., 1980e, Area Health Physics Monthly Report, March 1980, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5571 

Dummer, J.E., 1980e, Area Health Physics Monthly Report, April 1980, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5572 

Dummer, J.E., 1980e, Area Health Physics Monthly Report, May 1980, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5573 

Dummer, J.E., 1980e, Area Health Physics Monthly Report, June 1980, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5574 

Dummer, J.E., 1980e, Area Health Physics Monthly Report, July 1980, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5575 
13A-22 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A

Dummer, J.E., 1980e, Area Health Physics Monthly Report, August 1980, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5576 

Dummer, J.E., 1980e, Area Health Physics Monthly Report, September 1980, Los Alamos Scientific Laboratory, 

Los Alamos, New Mexico. Repos. No. 5577 

Dummer, J.E., 1980e, Area Health Physics Monthly Report, October 1980, Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 5578 

Dummer, J.E., 1980e, Area Health Physics Monthly Report, November 1980, Los Alamos Scientific Laboratory, 

Los Alamos, New Mexico. Repos. No. 5579 

Dummer, J.E., 1980e, Area Health Physics Monthly Report, December 1980, Los Alamos Scientific Laboratory, 

Los Alamos, New Mexico. Repos. No. 5580 

1981 Health Physics Reports

Dummer, J.E., 1981a, Quarterly Progress Report – Group H-1 Health Physics, January - March 1981, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392r 

Dummer, J.E., 1981b, Quarterly Progress Report – Group H-1 Health Physics, April - June 1981, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 448 

Dummer, J.E., 1981c, Quarterly Progress Report – Group H-1 Health Physics, July - September 1981, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 448 

Dummer, J.E., 1981d, Quarterly Progress Report – Group H-1 Health Physics, October - December 1981, Los 

Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 448, 5580 

Note: Starting in the third quarter of 1978, Area Heath Physics began reporting activities in separate monthly 

reports. 

Miller, J., Gallimore, J., Stafford, R., 1981a, Health Physics - Group H-1, Monthly Progress Report - Area Health 

Physics, January 1981, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5581 

Miller, J., Gallimore, J., Stafford, R., 1981b, Health Physics - Group H-1, Monthly Progress Report - Area Health 

Physics, February 1981, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5582 

Miller, J., Gallimore, J., Stafford, R., 1981c, Health Physics - Group H-1, Monthly Progress Report - Area Health 

Physics, March 1981, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5584 

Miller, J., Gallimore, J., Stafford, R., 1981d, Health Physics - Group H-1, Monthly Progress Report - Area Health 

Physics, April 1981, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5585 

Miller, J., Gallimore, J., Stafford, R., 1981e, Health Physics - Group H-1, Monthly Progress Report - Area Health 

Physics, May 1981, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5586 

Miller, J., Gallimore, J., Stafford, R., 1981f, Health Physics - Group H-1, Monthly Progress Report - Area Health 

Physics, June 1981, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5587 

Miller, J., Gallimore, J., Stafford, R., 1981g, Health Physics - Group H-1, Monthly Progress Report - Area Health 

Physics, July 1981, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5588 

Miller, J., Gallimore, J., Stafford, R., 1981h, Health Physics - Group H-1, Monthly Progress Report - Area Health 

Physics, August 1981, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5589 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A 13A-23

Miller, J., Gallimore, J., Stafford, R., 1981i, Health Physics - Group H-1, Monthly Progress Report - Area Health 

Physics, September 1981, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5590 

Miller, J., Gallimore, J., Stafford, R., 1981j, Health Physics - Group H-1, Monthly Progress Report - Area Health 

Physics, October 1981, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5591 

Miller, J., Gallimore, J., Stafford, R., 1981k, Health Physics - Group H-1, Monthly Progress Report - Area Health 

Physics, November 1981, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5592 

Miller, J., Gallimore, J., Stafford, R., 1981l, Health Physics - Group H-1, Monthly Progress Report - Area Health 

Physics, December 1981, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5593 

1982 Health Physics Reports

Dummer, J.E., 1982a, Health Physics Quarterly Progress Report, January - March 1982, Los Alamos Scientific 

Laboratory, Los Alamos, New Mexico. Repos. No. 6102 

Dummer, J.E., 1982b, Health Physics Quarterly Progress Report, April - June 1982, Los Alamos Scientific 

Laboratory, Los Alamos, New Mexico. Repos. No. 6103 

Dummer, J.E., 1982c, Health Physics Quarterly Progress Report, July - September 1982, Los Alamos Scientific 

Laboratory, Los Alamos, New Mexico. Repos. No. 6104 

Dummer, J.E., 1982d, Health Physics Quarterly Progress Report, October - December 1982, Los Alamos Scientific 

Laboratory, Los Alamos, New Mexico. Repos. No. 6105 

1983 Health Physics Reports

Dummer, J.E., 1983a, Quarterly Progress Report – Group H-1 Health Physics, January - March 1983, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 392s 

Note: Quarterly Progress Reports – Group H-1 Health Physics for April – June 1983, July – September 1983, and 

October – December 1983 were not located during project research activities. 

Miller, J., Gallimore, J., Stafford, R., 1983a, Health Physics Monthly Activity Reports - Operational, January 1983, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5653 

Miller, J., Gallimore, J., Stafford, R., 1983b, Health Physics Monthly Activity Reports - Operational, February 1983, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5654 

Miller, J., Gallimore, J., Stafford, R., 1983c, Health Physics Monthly Activity Reports - Operational, March 1983, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5655 

Miller, J., Gallimore, J., Stafford, R., 1983d, Health Physics Monthly Activity Reports - Operational, April 1983, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5656 

Miller, J., Gallimore, J., Stafford, R., 1983a, Health Physics Monthly Activity Reports - Operational, May 1983, Los 

Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5657 

Miller, J., Gallimore, J., Stafford, R., 1983a, Health Physics Monthly Activity Reports - Operational, June 1983, Los 

Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5659 

Miller, J., Gallimore, J., Stafford, R., 1983a, Health Physics Monthly Activity Reports - Operational, July 1983, Los 

Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5658 
13A-24 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A

Miller, J., Gallimore, J., Stafford, R., 1983a, Health Physics Monthly Activity Reports - Operational, August 1983, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5660 

Note: September 1983 Health Physics Monthly Activity Reports were not located during project research activities. 

Miller, J., Gallimore, J., Stafford, R., 1983a, Health Physics Monthly Activity Reports - Operational, October 1983, 

Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5661 

Miller, J., Gallimore, J., Stafford, R., 1983a, Health Physics Monthly Activity Reports - Operational, November 

1983, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5662 

Miller, J., Gallimore, J., Stafford, R., 1983a, Health Physics Monthly Activity Reports - Operational, December 

1983, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 5663 

1989 Health Physics Reports

Valentine, A. 1989c, Radiation Protection Quarterly Report, October – December 1989, Alamos National 

Laboratory, Los Alamos, New Mexico. Repos. No. 392aa 

1990 Health Physics Reports

Graf, J.M. 1990a, Radiation Protection Quarterly Report, April - June 1990, Alamos National Laboratory, Los 

Alamos, New Mexico. Repos. No. No. 392bb 

Graf, J.M. 1990b, Radiation Protection Quarterly Report, July - September 1990, Alamos National Laboratory, Los 

Alamos, New Mexico. Repos. No. No. 392cc 

Graf, J.M. 1990c, Radiation Protection Quarterly Report, October - December 1990, Alamos National Laboratory, 

Los Alamos, New Mexico. Repos. No. No. 392dd 

1991 Health Physics Reports

Graf, J.M. 1991, Radiation Protection Quarterly Report, October - December 1990, Alamos National Laboratory, 

Los Alamos, New Mexico. Repos. No. No. 392ee 

1975 EHS Reports

LASL (Los Alamos Scientific Laboratory), 1975a, Quarterly Progress Report, Operational Environmental, Health, 

and Safety Activities, January - March, 1975. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. 

No. 6239 

LASL (Los Alamos Scientific Laboratory), 1975b, Quarterly Progress Report, Operational Environmental, Health, 

and Safety Activities, April - June 1975. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

6240 

Note: A Quarterly Progress Report, Operational Environmental, Health, and Safety Activities for July - September 

1975 was not located during project research activities. 

Note: A Quarterly Progress Report, Operational Environmental, Health, and Safety Activities for October – 

December 1975 was not located during project research activities. 

LASL (Los Alamos Scientific Laboratory), 1975c, Quarterly Progress Report, Health Research Division – Indirect 

Laboratory Support Activities, January - March 1975. Los Alamos Scientific Laboratory, Los Alamos, New 

Mexico. Repos. No. 4993 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A 13A-25

LASL (Los Alamos Scientific Laboratory), 1975d, Quarterly Progress Report, Health Research Division – Indirect 

Laboratory Support Activities, April - June 1975. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. 

Repos. No. 4994 

1976 EHS Reports

LASL (Los Alamos Scientific Laboratory), 1976a, Quarterly Progress Report, Operational Environmental, Health, 

and Safety Activities, January - March, 1976. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. 

No. 6241 

LASL (Los Alamos Scientific Laboratory), 1976b, Quarterly Progress Report, Operational Environmental, Health, 

and Safety Activities April - June 1976. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

6242 

Note: A Quarterly Progress Report for July - September 1976 was not located during project research activities 

LASL (Los Alamos Scientific Laboratory), 1976d, Quarterly Progress Report, Operational Environmental, Health, 

and Safety Activities, October - December, 1976. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. 

Repos. No. 6243 

1977 EHS Reports

LASL (Los Alamos Scientific Laboratory), 1977a, Quarterly Progress Report, Operational Environmental, Health, 

and Safety Activities, January - March, 1977. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. 

No. 6237 

LASL (Los Alamos Scientific Laboratory), 1977b, Quarterly Progress Report, Operational Environmental, Health, 

and Safety Activities, April - June 1977. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 

6238 

LASL (Los Alamos Scientific Laboratory), 1977c, Quarterly Progress Report, Operational Environmental, Health, 

and Safety Activities, July -September, 1977. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. 

No. 6235 

LASL (Los Alamos Scientific Laboratory), 1977d, Quarterly Progress Report, Operational Environmental, Health, 

and Safety Activities, October - December, 1977. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. 

Repos. No. 6236 

1978 ESH Reports

Voelz, George L., 1978a, Quarterly Progress Report: January - March, 1978 Operational Environmental Safety and 

Health Activities, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. No. 893 

Voelz, George L., 1978b, Quarterly Progress Report: Operational Environmental Safety and Health Activities April 

- June, 1978, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. No. 896b 

Voelz, George L., 1978c, Quarterly Progress Report: Operational Environmental Safety and Health Activities JulySeptember, 1978, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6234. 

Voelz, George L., 1978d, Quarterly Progress Report: Operational Environmental Safety and Health Activities 

October - December, 1978, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 6244. 

1979 ESH Reports

Voelz, George L., 1979a, Quarterly Progress Report, January - March 1979, Operational Environmental Safety and 

Health Activities, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. No. 941 
13A-26 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Appendix 13A

Voelz, George L., 1979b, Quarterly Progress Report, April-June 1979, Operational Environmental Safety and Health 

Activities, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. number pending 

Voelz, George L., 1979c, Quarterly Progress Report, July - September 1979, Operational Environmental Safety and 

Health Activities, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 941 

Voelz, George L., 1979d, Quarterly Progress Report, October - December 1979, Operational Environmental Safety 

and Health Activities, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 941 

1980 ESH Reports

Voelz, George L., 1980a, Quarterly Progress Report, January - March 1980 Operational Environmental Safety and 

Health Activities, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 937 

Note: A Quarterly Progress Report for April – June 1980 was not located during project research activities. 

Voelz, George L., 1980b, Quarterly Progress Report, July - September 1980 Operational Environmental Safety and 

Health Activities, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 938 

LASL (Los Alamos Scientific Laboratory), 1981a, Health Division Quarterly Report, October - December 1980, 

Los Alamos National Laboratory, Los Alamos, New Mexico. Repos. No. 933. 

1987 HSE Reports

LANL (Los Alamos National Laboratory), 1987, Health, Safety, Environment Quarterly Report, July - September 

1987, Los Alamos, New Mexico. Repos. No. 3126. 

1988 HSE Reports

LANL (Los Alamos National Laboratory), 1988a, Health, Safety, Environment Quarterly Report, January - March 

1988, Los Alamos, New Mexico. Repos. No. 1246. 

LANL (Los Alamos National Laboratory), 1988b, Health, Safety, Environment Quarterly Report, October - 

December 1988, Los Alamos National Laboratory, Los Alamos, New Mexico. Repos. No. 5913 

1989 HSE Reports

LANL (Los Alamos National Laboratory), 1989, Health Safety Environment Quarterly Report, April - June 1989, 

Los Alamos National Laboratory, Los Alamos, New Mexico. Repos. No. 3570 

1990 HSE Reports

LANL (Los Alamos National Laboratory), 1990, Health Safety Environment Update, Summary of 1990 Quarterly 

Reports, Los Alamos National Laboratory, Los Alamos, New Mexico. Repos. No. 878
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14 14-1

Chapter 14: Environmental Monitoring at LANL 

This chapter presents a summary of environmental monitoring and research data that may be useful for 

evaluation of historical releases from Los Alamos National Laboratory. The reports and monitoring data 

reviewed by the LAHDRA project team represent samples or measurements collected in both on-site and 

off-site areas potentially affected by past contaminant releases from Los Alamos National Laboratory 

operations. The information presented here is organized chronologically to highlight changes and 

improvements that have occurred during the evolution of LANL’s environmental monitoring programs 

since the start of Laboratory operations in 1943. Details on monitoring practices presented in this chapter 

are more heavily weighted toward pre-1970 monitoring since it was during this time period that the 

largest releases occurred. 

Overall information availability is summarized in the following sections. Brief descriptions are included 

of several example environmental studies that are tied to past LANL activities. It is important to note 

that, while this chapter summarizes a number of environmental monitoring studies, it is not a complete 

historical record of every study conducted to date. Many more environmental studies are described and 

referred to in documents that were selected by the LAHDRA project team and added to the project 

information database. 

Areas of Investigation 

Environmental monitoring and research data reviewed by the LAHDRA project team primarily address 

sampling and measurement of environmental media such as air, water, soils, sediments, biota, and 

foodstuffs that were potentially impacted by radioactive and chemical contaminants released from LANL. 

Monitoring data of interest to this project represent measured concentrations of contaminants at on-site 

and off-site locations, including areas along the site boundary and residential communities that are 

nearby, regional, or useful for characterization of background concentrations. Historically, these data 

have typically been used by LANL to monitor trends in contaminant releases and/or to study the presence, 

migration, and fate of releases that have occurred or are occurring through transport mechanisms such as 

air dispersion, leaching, or surface flow to important water resources. Environmental monitoring data are 

of interest for potentially filling data gaps that exists in historical effluent monitoring data for various 

discharge points at LANL. 

The following section describes the primary geographical areas of interest during the investigation. These 

areas were selected for investigation based on: 
14-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14

• The LAHDRA project team’s knowledge of the key release sources at the Laboratory, 

• Previous environmental studies of on-site and off-site areas, 

• Surface waters that have received past LANL emissions, 

• Reported areas of contaminant accumulation in surface water, sediments, and surface and 

subsurface soils, 

• Annual airborne releases and indications of how they have been affected by local and regional 

wind patterns as well as local and regional topography, and 

• Historical environmental surveillance and monitoring and a review of environmental data 

availability. 

Some environmental monitoring within the laboratory boundary and surrounding areas began within the 

first few years after the start of Laboratory operations in 1943. Monitoring was first conducted by 

members of the Health Group of Project Y, the United States Atomic Energy Agency, and the U.S. 

Geological Survey (USGS). In more recent years, other LANL divisions and the State of New Mexico 

have also conducted environmental monitoring and/or environmental studies. Most of the early 

monitoring involved collection of non-routine air, water, soil, and sediment samples that were analyzed 

for radioactive and occasionally elemental or chemical contaminants. The early environmental 

monitoring program was used to identify and characterize the spread of radioactive contamination to 

surrounding land areas and to estimate potential radiation exposures to workers as a result of laboratory 

activities and emissions. 

Increased monitoring over the years meant the collection of a larger number of routine samples for all 

types of media and for a growing list of contaminants. The frequencies with which samples were 

collected also increased over the years. With the advent of new environmental protection and emission 

standards of the early 1970s, LASL saw the need to further increase their monitoring of the environment 

both on site and off site and enhance the formats with which they reported measurement results. The 

need to do more monitoring was also brought to the LASL’s attention by independent reviewers and 

experts (Parker 1974). 

Based on reports reviewed to date, most of the emphasis for environmental monitoring during the early 

years was placed on measuring radioactive constituents; however, beginning in the late 1950s, some 

limited sampling was performed for lead, mercury, chromium, beryllium, and other elements and 

chemicals of interest. Early environmental documents pointed out the need to increase sampling for all 

media and to perform radiochemical analyses for isotopic plutonium and specific fission products 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14 14-3

associated with fall-out from atmospheric weapon tests to better differentiate between global fallout and 

impacts from LASL (Parker 1974). 

The areas of concern for the investigation of environmental data include: 

• Los Alamos community 

• Española community 

• White Rock community 

• Surrounding Native American lands 

• Los Alamos Canyon 

• DP Canyon 

• Pueblo Canyon 

• Acid Canyon 

• Rio Grande River 

• Mortandad Canyon 

• Bayo Canyon 

• Pajarito Canyon 

• Sandia Canyon 

• Guaje Canyon 

• Area reservoirs 

Conditions at LANL and Surrounding Areas 

The laboratory site and adjacent communities are situated on the Pajarito Plateau, which consists of a 

series of mesas separated by deep canyons. These canyons were cut by intermittent streams that trend 

south-eastward from an altitude of about 2,400 meters at the Jemez Mountains to about 1,800 meters at 

the eastern margin, where they terminate above the Rio Grande Valley. The canyons and mesas areas are 

underlain by the Bandelier Tuff composed of ashfall and ashflow pumice and rhyolite tuff that form the 

surface of Pajarito Plateau. The volcanic ash was deposited following an eruption that occurred about 1.2 

million years ago (LASL 1980). 

Surface waters are primarily intermittent streams that begin on the sides of the Jemez Mountains and 

supply base flow to the upper reaches of some canyons. The amount of flow in these streams is typically 

insufficient to maintain flow across the laboratory area before it is depleted by evaporation, transpiration, 

and infiltration. However, runoff from heavy thunderstorms and significant snowmelts reaches the Rio 

Grande several times a year. Over portions of LANL’s operational history, effluents from the Laboratory 

have provided sufficient volume to maintain surface flow in the canyons for distances up to 1.5 km 

(LASL 1980). Several photographs of LANL discharges to area canyons are shown in Fig. 14-1.
14-4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14

Fig. 14-1. Discharges of liquid radioactive waste to Acid Canyon in the mid-1940s (left) and to DP 

Canyon in 1973. Photographs courtesy of LANL.

Groundwater occurs in three modes in the Los Alamos area: (1) water in shallow alluvium in the canyons, 

(2) perched water in basalt, and (3) the main aquifer of the Los Alamos area. Deposited alluvium in the 

canyons ranges in thickness from 1 to 30 m and is quick permeable in contrast to the underlying volcanic 

tuff and sediments. This results in a shallow alluvial groundwater that moves down gradient in the 

alluvium and becomes depleted as it moves into the underlying volcanic deposits. In lower Los Alamos 

and Pueblo Canyons, a small local body of perched water is formed in the basalts by water filtration. This 

water discharges in the Los Alamos Canyon west of the Rio Grande. The main aquifer capable of 

municipal water supply rises westward from the Rio Grande within the Tesuque Formation into the lower 

part of the Puye Formation beneath the central and western part of the plateau. Depth to the aquifer 

decreases from 360 m along the western margin of the Plateau to about 180 m at the eastern margin. The 

water is under water table conditions in the western and central part of the plateau and under artesian 

conditions in the eastern part and along the Rio Grande (LASL 1980). 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14 14-5

Availability of Environmental Data 

Much of the environmental monitoring results reported for years prior to 1970 and reviewed by the 

project team are published in letter-type reports that vary widely in content and detail. In some cases, 

only a portion of a report was available for review or a report may only contain limited amounts of 

monitoring data or lack a description of the methods and purpose for a monitoring activity. Information 

presented in these earlier documents indicates that environmental monitoring was sporadic and generated 

a smaller amount of data when compared to results for later years, when monitoring activities were much 

more formalized and comprehensive. 

By the late 1950s, attempts were made by the laboratory to formally consolidate environmental 

monitoring results into one report. One of the first such reports is titled Los Alamos Environmental 

Monitoring Program for the years 1959 and 1960. This report includes results for direct gamma 

measurements, air particulate sampling for analysis of alpha and beta air concentrations, and water 

sampling of potable water supplies, surface body waters, and test monitoring wells (Kennedy 1960). 

However, it was not until 1970, when LANL began to publish their annual environmental surveillance 

reports, that results of monitoring activities were routinely reported in a unified and comprehensive 

manner. Monitoring grew substantially over the next 35 years, with results published and documented in 

the annual environmental monitoring reports. Many of these annual reports are now available to the 

public on the laboratory’s Web site at www.lanl.gov. 

Chronology of Early Environmental Monitoring at LANL (1943 – 1970) 

Documents indicate that LANL began their first environmental monitoring activities sometime in 1944 or 

1945. Monitoring was designed to measure radioactive and chemical concentrations in water, sediments, 

and soils with the intent of defining the impacts to the environment from laboratory liquid waste 

discharges to nearby canyons or burial grounds. The monitoring program evolved in the 1950s and 

expanded to include additional sampling and radiation surveys. Along with increases in water and soil 

sampling locations and sample collection frequencies, LANL began routine gamma radiation 

measurements and air sampling for gaseous and particulate radionuclides or non-radioactive 

contaminants. LASL periodically reported results for these early sampling and radiation survey activities 

in brief letter reports. Reports often present combined results for water and soil samples, ambient gamma 

measurements, and air samples (Tribby 1945; Tribby 1947, Kinsley 1947; LASL 1954a; Kennedy 1965). 

Occasionally, LASL reported results for radioactive fallout particulates from LANL operations using 

“Sticky trays” with gummed-paper to collect the radioactive contamination (Kennedy 1958). These early 
14-6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14

sampling activities were sporadic and often involved non-routine monitoring to study changes in 

contaminant concentrations over time and movement of contaminants in the environment. 

An independent safety appraisal of the LASL health and safety program conducted in 1947 by the Safety 

and Industrial Health Advisory Board of the National Safety Council was highly critical of the 

laboratory’s ability to control and monitor releases of hazardous materials to the environment (Williams 

1948). In addition, LASL documents indicate that environmental monitoring lacked continuity and 

consistency in terms of sampling methods and data analysis and reporting. The use of staff from various 

groups operating somewhat independently from one another made it difficult to compile routine data into 

unified and consistent formats with the level of data and reporting quality that was desired (Kennedy 

1958). Effluent and environmental monitoring programs were not as well developed as the methods and 

practices used for monitoring personnel radiation exposures during this time period and it is evident that 

the health and safety program was primarily directed towards reducing radiation exposures to workers. 

Documents available to the project team indicate that routine environmental air sampling was almost 

nonexistent until the mid to late 1950s. 

Monitoring of Liquid Waste Releases

During early operations in the 1940s, liquid waste from the DP site (TA-21) and the Original Technical 

Area (TA-1) were released into Los Alamos Canyon and Pueblo Canyon. Periodic water and sediment 

samples were collected in the canyon creeks and drainage areas and in off-site areas such as the Rio 

Grande and analyzed for radioactive and chemical contaminant concentrations. Samples of liquid 

effluents were also collected at discharge points to determine if the amounts of waste released were within 

the legal or recommended concentration limits for the time and also used at the Hanford site (Tribby 

1948). Many of the samples during this time were analyzed for plutonium, polonium, uranium, beta and 

gamma, and occasionally for heavy metals and other elements such as lead, bismuth, mercury, chromium, 

and fluorine (Tribby 1945; Kingsley 1947; Kingsley et al. 1947; Schnap et al. 1948; Shipman 1958). 

Area supply wells and other potable water supplies were also sampled and tested (Kennedy 1948). The 

liquid effluent limits at that time were 6.3 x 10-4 μCi L-1 for plutonium and polonium and 5.0 x 10-1 μCi 

L-1 for mixed fission products such as 140La and 140Ba. The earliest LANL documents that describe initial 

monitoring activities and results are for 1945 to 1950 (Tribby 1945; Tribby 1947; Schnap et al. 1948; 

Schnap 1950). Treatment of the liquid waste was initially minimal, but did increase as production and 

liquid waste volumes increased (Tribby 1948). The following excerpt from a LANL document depicts 

the sources of contamination and environmental areas targeted for sampling (Tribby 1945). 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14 14-7

 

Water sampling was usually conducted after heavy rains since creek beds were often dry during seasonal 

periods of low precipitation. Many of the samples were collected in “pools” which is where liquid waste 

discharges and rainwater collected in lower-lying or down gradient drainage areas (Kingsley 1947). 

Concentrations for radioactive contaminants in water and soil samples were typically elevated at locations 

near effluent discharge points in the canyons and decreased to undetectable levels within short distances 

from points of discharge. Elevated levels were often identified during periods of liquid discharge but 

concentrations would decrease over time due to the decay of short-lived radionuclides such as polonium 

or from dilution and movement of longer-lived radioactive contaminants dispersed within surface waters 

during periods of moderate to heavy precipitation (Kingsley 1947; Schnap et al. 1948). Records indicate 

that LASL began to scale back on their liquid waste discharges to Los Alamos and Pueblo Canyons as 

additional waste treatment facilities at the laboratory became operational to reduce contaminants levels 

release to the canyons or burial grounds. 

LASL found it necessary to expand their waste treatment capacity as growing production and research 

demands generated larger and larger volumes of liquid and solid radioactive and chemical waste. H-7 

group became part of the H Division in June 1955 and assumed responsibility for liquid waste treatment 

Fig. 14-2. Excerpt from a LANL document depicts the sources of contamination and environmental 

areas targeted for sampling (Tribby 1945)
14-8 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14

and management. The H-7 Group also oversaw a growing environmental monitoring program in those 

areas potentially impacted by liquid and airborne discharges. Two liquid waste treatment plants used coprecipitation for removal of plutonium and one plant was equipped with an ion exchange unit to remove 

barium-140 and radioactive strontium isotopes (Shipman 1958). 

The Waste Treatment Plant at TA-45 received wastes from TA-1 and TA-3 and discharged treated liquid 

waste to Acid canyon. For example, 11.5 million gallons of waste was received in 1957. Treatment of 

the waste removed roughly 94% of the radioactivity and 99% of the plutonium, which allowed them to 

meet 10% of the NBS 52 Handbook tolerance for plutonium discharge (Shipman 1958). More treatment 

capacity was added as necessary and releases of contaminants decreased over time. 

The Ten Site Waste Treatment plant at TA-35 handled liquid waste for the RaLa program with four 

50,000 gallon tanks. Wastes contained mixtures of 140Ba, 140La, 89Sr, 90Sr, 90Y and trace amounts of other 

radionuclides. Waste treatment removed 93% of radioactivity and discharged roughly 92% of liquid 

waste volume to Mortandad Canyon after treatment (Shipman 1958). 

In coordination with LANL, the United States Geological Survey (USGS) also collected routine water 

samples from local surface streams, the Rio Grande, supply wells, and monitoring wells and submitted 

the samples to LANL for radiochemical and water quality analyses. Monthly samples were analyzed for 

gross alpha, gross beta, plutonium, and uranium. Samples were also analyzed for pH, total hardness, 

potassium, sulfur, calcium, magnesium, sodium, chloride, fluoride, total solids, NO3, and conductivity. 

Volumetric flow rates for streams located in Pueblo and Los Alamos canyons are also presented in study 

results. These additional sampling were also used to assess the potential impacts from LANL operations 

on water resources and to better understand the rate and direction of groundwater flow in the local and 

regional area (LASL 1959; Shipman 1956). 

By the 1970s, LANL was conducting water sampling at various locations at distances of 40 to 50 

kilometers away from the main laboratory area (LASL 1971a). Additional examples of early 

environmental monitoring studies of waterborne contamination are presented in a later section of this 

chapter. 

Soil Monitoring

LANL also conducted soil sampling at on-site and off-site locations to further assess impacts from liquid 

waste discharges from TA-1 and TA-21. Soil samples were collected in areas along canyon creeks or in 

dry creek beds and drainage areas. Samples were often analyzed for plutonium, polonium, uranium, beta 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14 14-9

and gamma heavy metals and other elements such lead mercury, chromium, and fluorine (Tribby 1945). 

Soil sampling results were reported along with results of their water monitoring activities. Concentrations 

results at on-site locations close to discharge points are often reported above detection limits or 

background levels. Results for sampling locations at greater from discharge points are often reported as 

“negative” meaning either concentration levels were below the method detection limits for analytical 

measurement techniques used at the time or were below an administrative or regulatory control limit 

(Kennedy 1952). 

Results for soil samples collected in Acid Canyon (discharge from TA-45 plant), Mortandad Canyon 

(discharge from TA-35 plant), Los Alamos Canyon (discharge from TA-21), and at the laundry site were 

periodically reported in Health Division of reports or memoranda (Shipman 1958). Samples during this 

time period were analyzed according to location– gross alpha and plutonium at Acid and Los Alamos 

Canyons and 90Sr and yttrium at Mortandad Canyon 

In 1955, soil sample results showed strontium contamination in upper reaches of Mortandad Canyon that 

exceeded NBS Handbook tolerance levels (Shipman 1958). Study of plutonium, strontium, and cesium 

movement in tuff materials was begun during 1957 and reported that very little movement of radioactive 

material had occurred based upon comparison to sampling results for the previous years. Soil sampling 

continued throughout the 1950s and beyond. Results consistently showed strontium contamination in the 

canyon from Ten Site liquid waste discharges (Shipman 1956). 

Grab and composite surface water samples were collected at various locations along the Rio Grande River 

and the Chama River. The rivers had a reported natural uranium background concentration of 

approximately 10-9 μCi cm-3. Water samples are also collected at 7 perennial streams, 13 water supply 

wells, and 8 test monitoring wells located in various canyons within and surrounding the laboratory 

(Shipman 1956). In 1957, LANL began a study to evaluate the movement of 90Sr, 137Cs, and 239Pu 

released form LANL through the local soils, including tuff material (Shipman 1958). 

By the 1970s, LANL was conducting soil and sediment sampling at various locations 40 to 50 km away 

from the site (LASL 1971a). Additional examples of early monitoring of soil contaminants and sampling 

studies are presented in a later section of this chapter. 

Air Monitoring

A variety of air monitoring activities and measurements conducted by LANL were also used as another 

means of assessing impacts from routine or accidental air effluents from laboratory operations or from resuspension of radioactively-contaminated soils or dry sediments. The primary focus of their early air 
14-10 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14

monitoring program from 1944 to around 1970 was to detect larger, accidental releases and as such this 

meant that routine sampling results at or below detection limits were not reported on a regular basis. 

These early monitoring stations were equipped with thin-walled GM tubes and a scaler/rate meter to 

record results. By the late 1950s and 1960s, air particulate filters and charcoal canisters were being used 

at most of these stations to measure gross alpha and beta and radioactive iodine concentrations in air. 

Routine reporting of these early measurements also appear to be sporadic and limited in the amount of 

data presented in LANL documents. It appears that only a limited amount of air monitoring results for 

1940s and 1950s and, to some extent the 1960s, was published by LANL. It is also possible that results 

were published in reports that are now missing or were destroyed or simply were not located by the 

project team. Routine reporting of monitoring results, however, does not appear to have begun in earnest 

until 1970 based on available documents reviewed by the project team. 

 LASL did not have a well established network of air monitoring stations until the late 1950s and 

documents indicate that 25 to 36 monitoring stations were used from 1958 to 1992. Most of these stations 

were located on-site within the various Technical Areas at LANL or within the Los Alamos town site or 

the town’s immediate surrounding areas. The two on-site monitoring stations furthest away from the 

Main Technical area or Los Alamos town site were located in White Rock, New Mexico (approximately 6 

miles to the southeast) and at the eastern site boundary. The report entitled Los Alamos Environmental 

Monitoring in the Vicinity of the Los Alamos Scientific Laboratory, January through June, 1971 (the 

predecessor report to LANL’s Annual Environmental Surveillance reports) indicates that LANL began to 

use two remote “off-site” air monitoring stations starting sometime in 1971. One station was placed in 

Española, New Mexico approximately 14 mi northeast of Los Alamos and the other station was located in 

Santa Fe, New Mexico, approximately 24 mi southeast of Los Alamos (LASL 1972a). 

In 1992 and 1993, LANL expanded the number of on-site monitoring stations to 52 including the addition 

of regional or remote stations at various locations up to approximately 45 mi northeast of LANL. The 

collective array of air monitoring stations became known as AIRNET monitoring program. During this 

expansion of air monitoring stations, LANL also increased the network to six off-site or remote 

monitoring stations. The remote stations since that time are located in Española, San Ildefonso Pueblo, El 

Rancho, and Jemez Pueblo New Mexico and still being used by LANL. An additional monitoring station 

was added within the city limits of Santa Fe. In 2003, LANL added a seventh remote monitoring station 

at Picuris Pueblo, New Mexico, making it the station furthest away from LANL at roughly 45 mi to the 

northeast. Most of these AIRNET stations or predecessor monitoring stations are still in operation today 

although routine or periodic reporting of monitoring results did not begin until the 1970s with the advent 

of LANL’s Annual Environmental Surveillance reports (LANL 1994; LANL 2008). Starting around the 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14 14-11

early to mid-1960s, air filters were measured for gross alpha and beta activities and then made into 

composite samples once a month for isotopic analyses of long-lived alpha-emitting radionuclides such as 

plutonium. Charcoal canisters also continued to be analyzed for 131I by way of gamma measurements and 

water vapor was measured for tritium concentrations via liquid scintillation counting. 

A comparison of environmental air monitoring programs at other DOE sites shows that LANL used 

similar measurement techniques throughout the years although they did not establish remote, off-site 

monitoring as early as some DOE sites. For example, the Oak Ridge Reservation (ORR) sites (X-10, Y12, and K-25) used a formal network of local and perimeter (“on-site”) samplers and monitors during the 

1940s and 1950s, but also began using remote (“off-site”) gamma and air monitoring stations in the early 

1960s. Eventually, the networks of monitoring stations were officially referred to as the local air 

monitors (LAMs), perimeter air monitors (PAMs), and remote air monitors (RAMs). ORR’s LAM and 

PAM monitoring stations used during this early period were equipped with ion-chamber type instruments 

to measure outdoor ambient gamma radiation levels. These instruments were later modified to measure 

beta radiation, although laboratory staff discovered the instruments were highly susceptible to weathering 

and proven to be unreliable for routine measurements. ORR eventually adopted the used of GM tubes 

with scaler/rate meters to measure both gamma and beta radiation. Charcoal canisters were used at 

selected stations for iodine measurements and tritium measurements were performed on rain water 

samples. Similar to the practices used by LANL, ORR also used film badges and TLDs in later years to 

measure gamma and beta radiation and air samplers to measure particulate and gaseous airborne 

concentrations of radioactive materials for determining impacts from site effluents and/or global nuclear 

fallout. 

ORR used three remote air monitoring (RAM) stations as far back as 1956. These stations were also 

equipped with GM Tubes and scalers along with gummed-paper trays and rain collectors for measuring 

air particulate radioactive contaminants/fallout along with charcoal canisters for measuring radioactive 

iodine. The first three RAMs used were located in Corryton and Kingston, Tennessee and Berea 

Kentucky. The Corryton and Kinston stations were only used in 1956 and data for the Berea station is 

only available for 1957 and 1958. The Berea station was discontinued in 1962. Prior to 1959, seven 

additional remote air monitoring stations were added at various Tennessee Valley Authority (TVA) dam 

locations ranging in distance approximately 12 to 75 miles from the ORR (NIOSH 2004). In comparison, 

LANL’s primary focus during early air monitoring was not on remote locations as much as it was on 

monitoring impacts to local residential areas and nearby canyons. It wasn’t until around 1970 that LANL 

began to expand their air monitoring network beyond its site boundary. 
14-12 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14

Bayo Canyon (TA-10) and TA-35 – RaLa Test Shots

LANL documents from the 1940s and early 1950s indicate that initial air monitoring conducted by LANL 

was focused on monitoring radioactive fallout from the RaLa test shots conducted in Bayo Canyon. 

Radioactive and chemical debris from test shots containing 140Ba and 140La was released to the 

atmosphere at dispersion rates and directional patterns based on weather conditions at the time of each 

shot. Airborne contaminants would typically migrate beyond Bayo Canyon to surroundings areas. As 

discussed in a 1945 LANL document, the three primary hazards associated with RaLa shots included 

external radiation, explosive materials, and airborne contamination. Airborne contamination was 

monitored at the firing location and at other points in the canyon and on the Los Alamos mesa initially by 

members of Group A-6 (Steinhardt 1945). Measurements were made with film badges mounted 3 feet 

above the ground surface on wooden or metal stakes. Direct gamma measurements were also collected 

with a GM tube and a scaler/rate meter. Later on fallout trays with gummed-paper were used to collect 

radioactive debris. 

Radioactive fallout from most test shots was monitored to the extent practical as LANL acknowledged 

that some downwind areas surrounding Bayo Canyon were inaccessible due to the rugged terrain in part 

of New Mexico. Following test shots, the road from the Main Tech area (TA-1) to the East Gate was 

often closed to vehicle traffic to allow time for removal and/or decay of radioactive contamination to 

levels deemed acceptable to allow resumption of public access on the roads. For example, the radioactive 

plume from a RaLa shot conducted on April 20, 1949 passed over and contaminated the area from the 

East Main Gate to Los Alamos town site. The incident required decontamination of the main road 

(Highway 285) before the road was reopened to the public or other workers. Because of these incidences, 

LANL sought to improve their weather and fallout predictions by requesting the assistance from 

meteorologists from the Kirkland Air Force Base in Albuquerque (LASL 1949a). 

Debris from another shot on May 20 of the same year drifted out of the canyon and contaminated the 

main road to Los Alamos at the Frijoles junction and resulted in maximum gamma-beta readings of 10 

mR h-1 (LASL 1949b). Throughout this time period, staff from the Biophysics section focused their 

efforts on further defining and predicting fallout from the RaLa shots to minimize exposures to workers 

and members of the public. In 1949, the fallout problem became more acute when LANL discovered a 

new mining operation in Guaje Canyon operated by the Santa Fe Pumice Company located about 3 mi 

away from Bayo Canyon. To minimize the spread of contamination and better characterize potential 

environmental and public health impacts from RaLa test shots, LANL increased their efforts to measure 

wind rose patterns including prevailing wind directions and maximum and average wind velocities of 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14 14-13

prevailing winds (LASL 1949c). As reported in a 1949 monthly H Division progress report, the plume 

from an implosion test shot rose and spread contamination easterly as far away as 10 mi at a location 

known as “Camp May” (LASL 1949d). 

Descriptions in the 1952 H Division annual report indicate that LANL continued to monitor dispersion 

and fallout of radioactive material from Bayo Canyon test shots. These surveys focused on tracking 

contamination in areas north and east of Bayo Canyon, White Rock, Totavi, Puje, and Espanola and to 

address growing concerns about releases from RaLa shots and from other facilities such as DP Site as 

production increased significantly during this period. In the report it was noted that additional sampling 

was conducted along East Road to assess impacts and hazards from DP Site as well as from Bayo Canyon 

releases. Health Division members from the H-1 and H-6 monitoring groups also expanded the on-site 

and off-site monitoring program to further address the growing concerns about impacts to the 

environment (Shipman 1953). 

Laboratory safety personnel also expressed concerns about personnel and public exposures associated 

with RaLa test shots as well as airborne effluents from RaLa hot cell operations and operations at TA-2 

(Omega), TA-3 (CMR Building), and TA-21 (DP Sites). The TA-35 hot cell facility was used to handle, 

store, and prepare the RaLa sources for test shots conducted in Bayo Canyon. The excerpt from a 1952 

LANL document shown in Fig. 14-3 represents another example of LANL activities used during this time 

to assess the impacts from the TA-35 radioactive airborne effluents (Buckland, 1952). 

The excerpt from a 1952 LANL document shown in Fig. 14-4 further indicates that LASL staff was 

aware of the importance of predicting weather conditions to minimize the spread of radioactive 

contamination and conducted periodic surveys to determine impacts of air effluents (Buckland, 1952). 

Other means of tracking cloud dispersions from the RaLa shots was through the use of air conductivity 

measurement. This technique proved to have advantages over the use of GM tube instruments, 

particularly when radiation fields approach saturation levels (LASL 1951). Based on review of project 

documents, it is not clear to what extent LANL used conductivity measurements in tracking radioactive, 

explosive cloud dispersions. 
14-14 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14

Fig. 14-3. Excerpt from a 1952 document that describes measurements of 

airborne radioactivity from RaLa processing at TA-35 (Buckland 1952)

Fig. 14-4. Excerpt from a 1952 LANL document describing wind 

patterns and dispersion of airborne effluents (Buckland 1952)

In a series of reports and memoranda from 1956 to 1959, monitoring of outdoor air concentrations and 

radiation levels within and surrounding TA-35 continued to be used to assess impacts from airborne 

effluents associated with 140Ba/140La source production, LAPRE operations, and irradiated reactor fuel 

analyses (including fission products) and plutonium experiments in hot cells (LASL 1959). Availability 

of these environmental monitoring data are limited based on document searches conducted by the project 

team. These types of data could be useful as a tool for evaluating the accuracy of effluent estimates 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14 14-15

reported by the lab or release estimates derived from basic effluent measurement data. Further research 

including document searches for these early environmental data is recommended to be part of any future 

dose reconstruction study of LANL operations. 

Main Technical Area and Greater Los Alamos and Surrounding Areas

In 1951, LANL continued to discuss the need to expand their air sampling program to improve the ability 

to measure contamination in areas outside of the Main Technical Area and DP Site resulting from 

laboratory activities. Health Division staff were recommending continuous operation of sampling stations 

at numerous locations adjacent to Los Alamos (LASL 1952). 

In 1954, LANL used ten air particulate monitoring stations within the Los Alamos community to measure 

airborne alpha concentrations during the demolition of D Building (Johnson 1954). Additional on-site 

stations were also used to study impacts from LANL operations with a focus on detecting and/or 

measuring radioactive releases from TA-1 (Main Technical Area), TA-2 (Omega reactor), TA-3 (CMR 

Building), TA-21 (DP Sites), TA-35 (RaLa hot cells, LAPRE, etc), and TA-10 (Bayo Canyon). During 

that same year, 14 air samplers were used at locations in the Main Technical Area (TA-1), Los Alamos 

town site including residential areas, and along the site perimeter (LASL 1954a). The locations for the 14 

air monitoring stations included: 

1636 34th Street South Mesa Road – Contractor Area 

194 Abbey Street Adjacent to Foundry Building at TA-1 

861 43rd Street Roof of O Building at TA-1 

2135 35th Street Roof of V-Shop at TA-1 

2500B 36th Roof of HRL Building at TA-1 

2379B Ivy Street Roof of Gamma Building at TA-1 

331A Manhattan Loop Warehouse 18 at TA-1 

Measurement results for 1954 are presented in two data sets (LASL 1954a, LASL 1954b). Monitoring 

results for previous years were not identified by the project team but further research to locate relevant 

records would likely be warranted during any future LANL dose reconstruction investigation. A 

thorough evaluation of the quality of these data is warranted if used in the future for evaluating the 

accuracy of effluent release estimates. 

In 1959, LANL proposed increasing air sampling for particulates to assess impacts from LANL 

operations on the surrounding communities by placing additional air samples on the rooftops of schools 

within the Los Alamos community (Kennedy 1959). By 1960, LANL’s air environmental monitoring 
14-16 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14

program had grown to 15 sampling locations to monitor airborne alpha contamination (including 

plutonium and polonium) and to assess any environmental impacts from laboratory operations (LASL 

1961b). During 1965 the number of sampling locations expanded to 25 air stations positioned within the 

Los Alamos residential areas and population centers (such as schools) and along perimeter roads 

throughout the various technical areas at the laboratory. As was the case during previous environmental 

air sampling activities, these samplers were used to measure airborne particulates and short-lived 

radioactive gases routinely released from LANL or for detecting large amounts of radioactive material 

released during accidents (Kennedy 1965). 

The air samplers used during this period contained two separate filter media to test for beta and gamma 

radioactivity. Mine Safety Appliance (MSA) 4-inch diameter CR-17651 respirator particulate filters were 

analyzed for beta (fallout) activity using a gas proportional counter calibrated with a 90Sr/90Y standard. 

Samples were collected on a daily basis and also periodically merged into composite samples for analysis 

of 90Sr, 137Cs, and 144Ce. A MSA BM 2306 charcoal canister was mounted behind the particulate filter and 

used for measuring gamma (radioiodine) activity. The charcoal canisters were measured for iodine 

activity on a gamma spectrometer calibrated with a 131I standard (Kennedy 1965). 

A second air particulate sampler was used for measuring long-lived alpha activity such as plutonium. 

Samples were collected on a Gelman AM-3, 2 inch diameter filters and analyzed on a gas proportional 

counter calibrated to a 239Pu standard. Samples were held for one week prior to counting to allow for the 

decay of natural radon and thoron. The lower limit of detection for these air samples was 4 x 10-15 μCi 

cm-3, or one-tenth the regulatory limit (4 x 10-14 μCi cm-3) used at that time. If results exceeded the 

regulatory limit, then samples were analyzed for radionuclide concentrations using alpha spectroscopy. A 

maximum value of 2 x 10-14 μCi cm-3 was reported for 1959 and 1960 with the average result below the 

method detection limit. A charcoal canister was also used on a percentage of these air samplers, but 

documents with a full or partial set of sampling results were not identified during documents performed 

during the project (Kennedy 1965). 

In 1993, LANL expanded the number of monitoring stations to 52 including regional locations as far 

away as Picuris Pueblo, New Mexico, located roughly 45 mi northeast of LANL (LANL 1994; LANL 

2008). 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14 14-17

Global Nuclear Fallout Measurements

Around 1958, LANL began specific collection of air particulate and rain water samples for analysis of 

beta radioactivity concentrations and performed gamma radiation measurements as part of the U.S. Public 

Health Service (PHS) program for reporting nuclear fallout data. LANL was one of eleven U.S Atomic 

Energy Commission sites that participated in the monitoring program and used one monitoring station 

located on the roof of laboratory’s Administration Building, SM-43 at TA-3 to serve this purpose 

(Kennedy 1960). The PHS program had a total of 44 monitoring stations located throughout the United 

States. Results were reported for airborne beta activity (pCi m-3),rain water radioactivity (pCi m-2), and 

gamma radiation (mR h-1). 

Results for the LANL nuclear fallout monitoring station are reported in a series of annual laboratory 

reports for the years 1958 to 1970 titled Beta-Gamma Radioactivity in Environmental Air at Los Alamos, 

New Mexico or Beta Radioactivity in Environmental Air at Los Alamos, New Mexico (see Table 14-1). 

Reports that contain pre-1958 sampling results were not located during this project although it is believed 

LANL may have conducted these types of measurements prior to these publications. Reported 

monitoring results for measured concentrations or radiation levels were typically consistent with 

background radiation levels or expected nuclear fallout amounts and did not show elevated levels from 

LANL operations. However, the monitoring station was located west or north and most often upwind of 

LANL’s primary production areas (e.g., TA-3, TA-10, TA-21, TA-35) and would not have been expected 

to routinely collect and measure activity released from these LANL process operations. 

In March of 1963, the H-8 monitoring group relocated their offices to TA-50 and moved the fallout air 

station to the roof of their new building which was located about 1.5 southeast of the TA-3 

Administration Building (Aeby and Kennedy, 1964). 

In 1964, LANL published results for long-lived fission products measured in rain water and air particulate 

samples continuously collected from 1958 through 1963. The purpose of the report was to describe 

isotopic analyses of composite samples and present concentration values for 90Sr, 137Cs, and radioactive 

rare earth elements (Graham 1964). 
14-18 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14

• Radioactivity in Environmental Air at Los Alamos, New Mexico for the Period November 

17, 1958 - December 31, 1959. LAMS-2397 (Kennedy 1960). 

• Beta-Gamma Radioactivity in Environmental Air at Los Alamos, New Mexico for 1960. 

LAMS-2499 (Kennedy 1961). 

• Beta-Gamma Radioactivity in Environmental Air at Los Alamos, New Mexico, for 1st

Quarter 1961. ER37183. Los Alamos, New Mexico. (Kennedy 1961a). 

• Beta-Gamma Radioactivity in Environmental Air at Los Alamos, New Mexico for 1961. 

LAMS-2702 (Kennedy 1962). 

• Beta-Gamma Radioactivity in Environmental Air at Los Alamos, New Mexico for 1962. 

LAMS-2870. (Aeby and Kennedy 1963). 

• Beta-Gamma Radioactivity in Environmental Air at Los Alamos, New Mexico for 1963. 

LAMS-3071. (Aeby and Kennedy 1964). 

• Beta-Gamma Radioactivity in Environmental Air at Los Alamos, New Mexico for 1964. 

LAMS-3245. (Aeby and Kennedy 1965). 

• Beta-Gamma Radioactivity in Environmental Air at Los Alamos, New Mexico for 1965. 

LAMS-3516. (Aeby and Kennedy 1966). 

• Beta-Gamma Radioactivity in Environmental Air at Los Alamos, New Mexico for 1966. 

LAMS-3663. (Aeby and Kennedy 1967). 

• Beta-Gamma Radioactivity in Environmental Air at Los Alamos, New Mexico for 1967. 

LA-3887. (Aeby and Kennedy 1968). 

• Beta-Gamma Radioactivity in Environmental Air at Los Alamos, New Mexico for 1968. 

LA-4133. (Aeby and Kennedy 1969). 

• Beta-Gamma Radioactivity in Environmental Air at Los Alamos, New Mexico for 1969. 

LA-4388. (Aeby and Kennedy 1970). 

• Beta-Gamma Radioactivity in Environmental Air at Los Alamos, New Mexico for 1970. 

LA-4661. (Aeby and Kennedy 1971). 

Table 14-1. LANL publications on nuclear fallout measurements

Gamma Monitoring

Direct gamma exposure rates or integrated gamma measurements were used to further define changes in 

environmental conditions as a result of airborne and waterborne releases from LANL operations. As 

described in a 1948 monthly H Division report, film badges on South Mesa were planted for daily 

monitoring (see Fig. 14-5) (LASL 1948). No further details on when this monitoring began are provided 

in the report and a search for these monitoring data did not identify any additional records. These types of 

data could provide useful, supplemental information regarding impacts from early effluents during the 

1940s and could be used to assess direct radiation exposures for periods when effluent amounts are 

difficult to ascertain due to a lack of effluent monitoring data. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14 14-19

Fig. 14-5. Document excerpt discussing planting of film badge dosimeters on South Mesa (LASL 1948)

Descriptions in another 1948 monthly H Division progress report indicate that the film badges where 

placed on top of South Mesa to monitor radioactive cloud dispersion associated with RaLa implosion test 

shots carried out in Bayo Canyon (LASL 1948). 

Sometime during 1949, direct gamma and beta exposure rates were monitored Geiger-Mueller (G-M) 

instruments with continuous monitoring and telemetry to a central location (see Fig. 14-6). These 

instruments were deployed in the Los Alamos area at six separate locations to provide another method for 

monitoring changes in the outside environment from LANL operations (LASL 1950). 

Fig. 14-6. Document excerpt discussing development of instruments for beta-gamma monitoring 

around Los Alamos (LASL 1950)

Sometime during the 1950s, the six stations were expanded to seven locations as described in a 1959 

LANL report. Twenty-four hour continuous readings were transmitted through telephone lines to a 

central recording station located at the main Administration Building. The transmitted readings were 

documented on automatic chart recorders. Variations in radiation levels were identified and most often 

determined to be attributable to variations in natural background radiation (Kennedy 1960b). It appears 

that these monitors remained in service throughout the 1960s and perhaps longer. A directed search for a 

complete set of these measurement results was unsuccessful during the project. 

During the 1950s, beta and gamma monitor were designed and built at the laboratory to assess impacts 

from releases from the Omega Water Boiler reactor. Locations of these monitors were not stated in the 

report (LASL 1950b). 
14-20 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14

Additional ambient gamma exposure levels were routinely measured with film badges mounted on stakes 

1 m above the ground surface. These badges were exchanged on a monthly basis. The film had a 

reported sensitivity above ambient background levels that approached the Radiation Protection Guide 

value used during this period. Any measurable dose recorded was then attributable to LANL effluents or 

other man-made sources of radiation (e.g., nuclear weapon test fallout). For 1960, 2400 gamma 

measurements were reported, and with the exceptions for 2 locations, all results were less than the 0.5 

rem, the public dose limit used at the time and recommended by the Federal Radiation Council (Federal 

Register; May 18, 1960) (Kennedy 1961b). Records that contain detailed results of these measurements 

were not identified during the project. 

By 1965, LANL used thermoluminescent dosimeters (TLDs) at 100 locations throughout the Los Alamos 

residential areas and surrounding areas on LANL property. The dosimeters were used to assess ambient 

gamma radiation levels and detect potential impacts from radionuclide emissions from the laboratory, 

particularly larger releases associated with accidents or other uncontrolled events (Kennedy 1965). The 

dosimeters were collected and analyzed on a monthly basis. A directed search for pre-1970 measurement 

results was unsuccessful during the project. By 1970, LANL reduced the number of TLD stations to 60 

locations based on prior measurement experience (e.g., redundancy of adjacent monitoring locations) and 

the recognition that for future monitoring one location provided adequate spatial coverage in some areas 

that had used two to three TLDs during prior monitoring periods. However, LANL increased the number 

of TLD locations again in 1981 and has maintained more than 150 since that time. 

Summary of Annual Environmental Surveillance Reports (1970 – 2007) 

Beginning in 1970, as environmental monitoring increased, LASL began to publish annual reports for 

environmental monitoring results based on sampling and analyses conducted by laboratory staff and the 

USGS. These reports contain monitoring results for a variety of environmental sample types, including: 

• direct radiation readings for alpha, beta, and gamma radiation, 

• outdoor/external thermoluminescent dosimeters (TLDs), 

• surface water including drainage ditches, creeks, ponds, rivers, and lakes, 

• ground water, 

• particulate and gaseous air sampling, 

• soil and sediment sampling, 

• food sources, 

• assorted biota and wildlife, and 

• special environmental sampling and research studies. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14 14-21

In the early 1970s, environmental samples were collected and analyzed by the Laboratory’s 

Environmental Services Group. Table 14-2 identifies the annual reports that have been published and 

Table 14-3 presents a summary of chemical and radionuclide monitoring data that are available in the 

annual environmental surveillance reports. 

Data contained in the annual reports represent samples routinely collected in air, surface water, ground 

water, soils, sediments, a variety of biota, and some food sources. The laboratory did not perform any 

measurements of food sources until the later part of the 1970s. The annual reports also contain 

information about special studies conducted to provide better coverage of areas of particular interest or to 

study in detail individual sources of contamination. For example, a study of radionuclide uptake in 

garden plants grown in the Mortandad Canyon was initiated in 1976 and reported in the Environmental 

Surveillance at Los Alamos During 1977 report (LASL 1978). Additional descriptions of the types of 

monitoring data contained in the annual reports are presented below. 

Examples of Early Environmental Studies of Interest

This section presents various environmental monitoring and research data that describe the historical 

presence and behavior of contaminants in off-site areas around LANL. Media addressed include surface 

water, sediment, ambient air, aquatic and terrestrial foodstuffs, soil, drinking water, and groundwater. 

Hydrologic and meteorological data are also presented below. Descriptions of additional studies will be 

added to this section as more information becomes available to the project team. 

Historical Surface Water and Sediment Data

Sample of available surface water and sediment monitoring data collected in areas of concern described in 

the above section are presented below. Due to large volumes of data, not all of the available data have 

been summarized for this report. 

Study #1: Radioactivity in Los Alamos and Pueblo Creek (1945-1947)– Some of the earliest 

measurement results for samples collected from wastewaters released from the Technical Area into 

Pueblo and Los Alamos Canyons are reported. Samples were collected at various points along the creeks 

and terminated at the Rio Grande River about 0.25 miles downstream of Otowi Bridge (Tribby 1945; 

Tribby 1947). The samples were analyzed for plutonium and polonium. A detection limit of 20 

disintegrations per minute per liter of creek water was reported at that time. One-liter samples were 

collected at each location and submitted to counting laboratory for analyses. 
14-22 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14

Table 14-2. Annual Environmental Monitoring and Surveillance Reports 

Starting in 1970, LASL began publishing annual reports that describe annual environmental monitoring 

results of media sampled both on-site and off-site at the laboratory. The data contained in these 

reports represent a wide range of sample types and sampling frequencies and to a more or lesser 

extent vary according to priorities and emphasis placed on monitoring and surveillance during a given 

year. Annual reports available for review during this and any future health studies are listed below. 

Period LANL Report No. LAHDRA Repos. No. 

January - June 1970 none 1000 

July - December 1970 LA-4672-MS 2178 

January - June 1971 LA-4871-MS 4079 

July - December 1971 LA-4970 4079 

1972 LA-5184 4078 

1973 LA-5586 2161 

1974 LA-5977-PR 2133 

1975 LA-6321-MS 2158 

1976 LA-6801-MS 2159 

1977 LA-7263-MS 2069 

1978 LA-7800-ENV 953 

1979 LA-8200-ENV 2190 

1980 LA-8810-ENV 930 

1981 LA-9349-ENV 929 

1982 LA-9762-ENV 1314 

1983 LA-10100-ENV 2342 

1984 LA-10421-ENV 654 

1985 LA-10721-ENV 1319 

1986 LA-10992-ENV 4074 

1987 LA-11306-ENV 4075 

1988 LA-11628-ENV 4076 

1989 LA-12000-ENV 1088 

1990 LA-12271-MS 2311 

1991 LA-12572-ENV 2189 

1992 LA-12764-ENV 1089 

1993 LA-12973-ENV 3903 

1994 LA-13047-ENV 3857 

1995 LA-13210-ENV 3849 

1996 LA-13343-ENV 4077 

1997 LA-13487-ENV 3863 

1998 LA-13633-ENV 3892 

1999 LA-13775-ENV 3873 

2000 LA-13861-ENV 3875 

2001 LA-13979-ENV 6198 

2002 LA-14085-ENV 6199 

2003 LA-14162-ENV 6200 

2004 LA-14239-ENV 6201 

2005 LA-14304-ENV 7989 

2006 LA-14341-ENV 7990 

2007 LA-14369-ENV 7991 
 Table 14-3. Data Availability - LANL Annual Environmental Surveillance Reports (1971 - 1999)

Sampling 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 Airborne releases- rad. ••••••••••••••••Airborne releases- chem. ••••••Air- gross alpha ••••••••••••• Air- gross beta ••••••••••••••••Air- 241Am ••• ••••••••••

Air- 238Pu ••••••••••••••••

Air- 239Pu ••••••••••••••••Air- 234

U • • 

Air- 235

U • • 

Air- 238

U • • 

Air- total U ••••••••••••••••Air- 131I • • • 

Air- 41

Ar •

Air- 3

H •• •••••••••••••

Air- beryllium • • 

Air- lead • •Air- cadmium • •Air stations (#) 58 35 36 26 26 29 30 25 25 25 25 25 26 26 26 26 Fish- 238Pu • ••••••••

Fish- 239Pu • ••••••••Fish- 137Cs • ••••••••Fish- 90

Sr •••••

Fish- uranium ••••••••Fruits- 238Pu ••••••••••••

Fruits- 239Pu ••••••••••••Fruits- 137Cs •

Fruits- 90

Sr ••••••••

Fruits- tritium •••••••••••Fruits- uranium ••••••••••••Groundwater- Rad. ••••••••••••••Groundwater- Chem. •••••••••••••Liquid releases- Rad. ••••••••••••••••Liquid releases- Chem. ••••••••••••••••Meteorological data ••••••••••••••••Milk- Rad. • • 

Municipal liq. discharge ••••••Sediment- gross alpha •••••••••••• Sediment- gross beta •••••••••••• Sediment- gross gamma ••••Sediment- 238Pu ••••••••••••••••

Sediment- 239Pu ••••••••••••••••Sediment- 241Am • 

Sediment- 137Cs ••••••••••••••••

Sediment- 90

Sr •••••••••••

Sediment- tritium ••••••••••••••••Sediment- uranium •• ••••••••••••

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 14 
 Table 14-3. Data Availability - LANL Annual Environmental Surveillance Reports (1971 - 1999)

Sampling 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 Soil- gross alpha ••••••••••••••••Soil- gross beta ••••••••••••••••Soil- gross gamma ••••Soil- 238Pu ••••••••••••••••

Soil- 239Pu ••••••••••••••••Soil- 241Am • 

Soil- 137Cs ••••••••••••••••

Soil- 90

Sr •••••••••••

Soil- tritium ••••••••••••••••Soil- total uranium • ••••••••••••Surface water- alpha ••••••••••••••••Surface water- beta ••••••••••••••••Surface water- gamma ••• Surface water- 241Am ••••• •••• 

Surface water- 238Pu ••••••••••••••••

Surface water- 239Pu ••••••••••••••••Surface water- 137Cs ••••••••••••••••Surface water- 90

Sr • •••••• 

Surface water- tritium ••••••••••••••••Surface water- uranium ••••••••••••••••Surface water- beryllium • •Surface water- cadmium • •Surface water- lead • •Surface water- mercury • •Surface water- chemical ••••••••••••••••Ve

getables- 238Pu ••••••••••••

Ve

getables- 239Pu ••••••••••••

Ve

getables- 137Cs •••••

Ve

getables- 90

Sr ••••••••

Vegetables- uranium ••••• •••••Vegetables- tritium ••••• 

Vegetation- plutonium •Water (potable)- Rad. ••••••••••••••••Water (potable)- Chem. ••••••••••••••••Solid Waste Disposal •TLD's (on-site/off-site) 58 59 65 22 44 48 50 55 50 61 152 155 155 155 155 155 Radiation Dose Ass. ••••••••••••••Special Studies •• ••••••••••••Honey bees- Rad. ••• •••••Unplanned releases •••••••••••••

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 14 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14 14-25

Study #2: Radioactivity in Los Alamos and Pueblo Creek (1947-1949)-- Samples were collected at 

various points along streams inside Los Alamos and Pueblo Canyons and analyzed for plutonium, 

uranium, polonium, and gross beta/gamma (Schnap et al. 1948a; Schnap 1950). 

Four liquid discharge pipes that serviced Technical area 2 (TA-2) and two liquid discharge pipes that 

serviced Technical Area 3 (TA-3) all discharged liquid wastes to separate two seepage pits systems. 

These pits were designed to hold the liquids for seepage to underlying soils and evaporation, but are 

reported to have clogged on occasion and resulted in release of waste liquids to Pueblo Canyon. 

Monitoring of radioactive contamination within surrounding canyons was performed to determine the 

impact from these early waterborne releases. Documented in reports as early as 1945, direct alpha, beta, 

and gamma radiation surveys were conducted by LASL personnel along the discharge drainage areas 

immediately down-gradient of the discharge pipes (i.e., canyon walls) and throughout drainage areas of 

the canyons. Water samples from each discharge pipe were collected and analyzed for plutonium, 

uranium, mixed fission products, fluorine, and toxic metals. Plutonium was measured in effluent waters 

released from TA-1 and TA-2 operations and ranged up to 1% by weight (Tribby 1947). During these 

early years, TA-3 did not handle plutonium compounds and concentrations usually averaged around 0.01 

dpm L-1. Seepage pits were also surveyed for radioactive contamination and found to be highly 

radioactive. 

Results for selected soil samples collected around TA-1 and TA-2 seepage pits in 1947 revealed levels of 

plutonium up to 50 dpm g-1. Polonium levels around TA-3 seepage pits were measured up to 3,000 dpm 

g-1. In 1947, Tribby reported that plutonium levels on canyon walls and canyon beds near discharge points 

were quite high and that concentration levels drop-off rapidly 100 ft and beyond release points. 

Waterborne radioactive waste was released without treatment to Acid Canyon from 1944 to 1951, when a 

treatment plant at TA-45 became operational. From 1951 to mid-1953, the TA-45 waste treatment 

facility only treated liquid waste from the Original Technical Area (TA-1). Beginning in the second half 

of 1953, wastes from TA-1 and TA-3 were treated at TA-45. 

From 1953 through the 1960s, wastes from TA-1 and TA-3 were treated at the TA-45 Waste Treatment 

Facility and discharged to Pueblo Canyon. Ferric sulfate and lime were added to incoming wastes to form 

a precipitate of ferric hydroxide which contained most of the plutonium which would in turn settle to the 

bottom of the waste storage tanks. Also during this period, liquid wastes from DP West production area 

were treated at the DPW Area Waste treatment Plant and released to Los Alamos Canyon. 
14-26 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14

Study #3: Radioactivity in Los Alamos, Pueblo, and Bayo Canyons (1957–1958) – During 1957 and 

1958, the U.S. geological Survey collected water samples from streams located in Los Alamos and Pueblo 

Canyons. These locations include: 1) Pueblo Canyon at Otowi Ruins, 2) Los Alamos canyon at bridge, 3) 

Los Alamos Canyon at Totavi, and 4) Bayo Canyon (Abrahams, 1958a; Abrahams, 1958b). 

Study #4: Radioactivity in Rio Grande (1957–1958) – During 1957, the U.S. Geological Survey 

collected water samples from the Rio Grande. Monthly samples were analyzed for gross alpha, 

plutonium, and uranium, and gross beta. Samples were collected at stations Embudo, Chama, Otowi, and 

Cochiti (Abrahams 1958a; Abrahams 1958b). 

Study #5: Radioactivity, Chromate, and Zinc in DP, Los Alamos, Pueblo, Mortandad, and Sandia 

Canyons (1969-1970) – During 1969 and 1970, LASL (H-8 Group) reported measured radioactivity 

levels for surface water samples collected from streams located in DP, Los Alamos, Pueblo, Mortandad, 

and Sandia Canyons. Monthly and quarterly samples were analyzed for gross alpha, gross beta, 

plutonium-238, plutonium-239, americium, strontium, cesium, tritium, and uranium (Kennedy, 1971). A 

limited number of samples were also analyzed for hexavalent chromium and zinc. 

Study #6: Plutonium in Pueblo and Acid Canyons (1970) – Sediment samples collected along Pueblo 

Canyon drainage basin show a decreasing trend in plutonium levels as a function of distance from LANL 

discharge points (Hanson, 1973). Based on a limited number of samples the following plutonium 

concentrations in sediment are reported: 

• 27 pCi g-1 in lower Acid Canyon 

• 4.6 pCi g-1 in Pueblo Canyon 1 mi below Acid Canyon 

• 1.1 pCi g-1 in Pueblo Canyon 2 mi below Acid Canyon 

• 1. pCi g-1 in Pueblo Canyon 0.1 mi above the junction with Los Alamos Canyon 

Detailed survey results are reported in document LA-4561, and will be reviewed by the project team for 

the next version of this report. The reported estimate of plutonium releases from TA-1 and TA-45 to 

Pueblo Canyon from 1944 to 1964 is 170 mCi (Hanson 1973). Plutonium measured in surface water 

samples collected in Acid and Pueblo Canyons averaged 20 pCi L-1 during this period, compared to 1.5 

and 0.22 pCi L-1 in Mortandad and Los Alamos Canyons, respectively. 

Study #7: Radioactivity in Bayo Canyon (1977) – During 1977, LASL collected surface water samples 

from Bayo Canyon. Radiochemical analysis of samples showed that residual 90Sr concentrations in soil 

averaged for the time period was 1.4 pCi g-1 (LASL 1978b). 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14 14-27

Historical Soil Monitoring Data

Samples of available soil monitoring data collected in areas of concern described in the above section are 

presented below. 

Study #1: Radioactivity in Los Alamos Canyon (1947) – Soil samples were collected along the canyon 

walls and at various locations along the canyon floor and analyzed for plutonium, polonium, uranium, 

other unspecified radionuclides, fluorine, and unspecified toxic metals (Tribby 1947). The available copy 

of this memo report reviewed by the project team appears to contain limited data for these surveys and/or 

is missing some of the sample results and warrants further research for data of this time period. 

Study #2: Radioactivity in Los Alamos and Pueblo Creek (1947) – Soil samples were collected at 

various points along streams inside Los Alamos and Pueblo Canyons and analyzed for plutonium, 

uranium, polonium, and gross beta/gamma (Schnap et al. 1948a). 

Study #3: Radioactivity in Bayo Canyon (1973-1977) – During 1977, LASL collected soil samples from 

Bayo Canyon and analyzed them for radioactivity. Study results showed that residual 90Sr concentrations 

in soil averaged 1.4 pCi g-1 (LASL 1978b). Previously reported surveys cited in this report include 

measured soil concentration results for gross alpha, gross beta, cesium, plutonium, and uranium. 

Historical External Radiation Monitoring Data 

Samples of available external radiation monitoring data collected in areas of concern described in the 

above section are presented below. 

Study #1: Direct Radiation Readings in Los Alamos Canyon (1947) – Direct radiation measurements 

with a Geiger Mueller survey meter were collected throughout Los Alamos Canyon as some of the first 

reported measurements of this type. The discharge line, canyon walls directly below the wastewater 

discharge point, and the canyon floor exhibited the highest readings up to 20,000 counts per minute of 

alpha radioactivity (Tribby 1947). 

Study #2: Radiation Levels in Mortandad Canyon (1952) – In 1952, LASL scientists conducted a series 

of radiation surveys throughout Mortandad Canyon following an accidental release of 2000 to 3000 

gallons of “hot water” from waste storage tanks located at the TA-35 Liquid Waste Treatment Plant. 

Survey results indicated that migration of measurable radioactive contamination had occurred several 

miles downstream in the canyon. Reported radiation dose rate readings ranged from 0.5 milliroentgens 

(mR) per hour at a distance of three miles to 300 mR h-1 at the TA-35 perimeter fence (Aeby 1952). The 
14-28 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14

report also discusses a planned release to the canyon of 50,000 gallons of radioactive liquid waste with a 

concentration of 1.5 mCi L-1, significantly above the tolerance limit. Specific isotopes are not stated in 

the memo report. Based on other information obtained about operations at the TA-35 for this time period, 

it is assumed the released waste contained 140Ba, 140La, trace amounts of 89Sr 90Sr, and other radionuclides 

(LASL 1957); 

Study #3: Radioactivity in Bayo Canyon (1973-1977) – Direct radiation measurements throughout Bayo 

canyon were taken with ion chambers and germanium detectors (LASL 1978b). 

Historical Ambient Air Monitoring Data

Samples of available ambient air monitoring data (including meteorological) collected in areas of concern 

described in the above section are presented below. 

Study #1: LANL Meteorological Data (1956 to 1971) – Measured wind, temperature, pressure, humidity, 

and precipitation collected at various locations throughout the Los Alamos and surrounding areas are 

presented (LANL 1976). 

Study #2: Beta/Gamma Concentrations at LANL (1961) – Airborne radioactive particulate samples 

collected on filter paper are reported for an air sampler located on the roof of the Administration Building 

SM-43. Air samples were collected every 24 h and 72 h over weekends (LASL, 1961). Report contains 

sampling results for the first quarter, 1961. 

Historical Groundwater/Water Supplies Monitoring Data

Samples of available groundwater monitoring data collected in areas of concern described in the above 

section are presented below. 

Study #1: Radioactivity in Los Alamos, Pueblo, and Guaje Canyons (1957-1958) – During 1958, 

groundwater, water supplies, and springs located in the Los Alamos area and in Los Alamos, Pueblo, and 

Guaje Canyons were sampled by the U.S. Geological Survey. The samples were analyzed for pH, gross 

alpha, plutonium, uranium, gross beta, total hardness, potassium, sulfur, calcium, magnesium, sodium, 

chloride, fluoride, total solids, NO3, and conductivity (Abrahams 1958a; Abrahams 1958b). 

Study # 2: Radioactivity and Other Constituents in U.S. Geological Water Samples (1960) – During 

1960, groundwater and water supplies were sampled by the U.S. Geological Survey. The samples were 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14 14-29

analyzed for pH, gross alpha, plutonium, uranium, gross beta, total hardness, calcium, magnesium, 

sodium, chloride, fluoride, total solids, and conductivity (USGS, 1961). 

Study #3: Chromate and Zink in Sandia Canyon (1969-1970) – During 1969 and 1970, LASL (H-8 

Group) reported hexavalent chromium and zinc levels in groundwater samples collected from monitoring 

wells located in Sandia Canyon (Kennedy 1971). 

References for Environmental Data 

Abrahams, J.H. 1958a. Quarterly Progress Report on Work at Los Alamos, New Mexico; U.S. 

Geological Survey, February – December 1957. Repos. No. 768. 

Abrahams, J.H. 1958b. Quarterly Progress Report on Work at Los Alamos, New Mexico; U.S. 

Geological Survey, January – March 1958. Repos. No. 768. 

Aeby, J.W. 1952. Monitoring in Mortandad Canyon (memorandum to D.D. Meyer, October 28, 1952). 

Los Alamos, New Mexico. Repos. No. 277. 

Aeby, J. W, and Kennedy, W. R. 1963. Beta-Gamma Radioactivity in Environmental Air at Los Alamos, 

New Mexico for 1962. LAMS-2870. Repos. No. 2185. 

Aeby, J. W, and W.R. Kennedy, 1964. Beta-Gamma Radioactivity in Environmental Air at Los Alamos, 

New Mexico for 1963. LAMS-3071. Repos. No. 2183. 

Aeby, J. W, and W.R. Kennedy, 1965. Beta-Gamma Radioactivity in Environmental Air at Los Alamos, 

New Mexico for 1964. LAMS-3245. Repos. No. 2182. 

Aeby, J. W, and W.R. Kennedy, 1966. Beta-Gamma Radioactivity in Environmental Air at Los Alamos, 

New Mexico for 1965. LAMS-3516. Repos. No. 2180. 

Aeby, J. W, and W.R. Kennedy, 1967. Beta-Gamma Radioactivity in Environmental Air at Los Alamos, 

New Mexico for 1966. LA-3663. Repos. No. 2169. 

Aeby, J. W, and W.R. Kennedy, 1968. Beta-Gamma Radioactivity in Environmental Air at Los Alamos, 

New Mexico for 1967. LA-3887. Repos. No. 2168. 

Aeby, J. W, and W.R. Kennedy, 1969. Beta-Gamma Radioactivity in Environmental Air at Los Alamos, 

New Mexico for 1968. LA-4133. Repos. No. 2166. 

Aeby, J. W, and W.R. Kennedy, 1970. Beta-Gamma Radioactivity in Environmental Air at Los Alamos, 

New Mexico for 1969. LA-4388. Repos. No. 2165. 

Aeby, J. W, and W.R. Kennedy, 1971. Beta-Gamma Radioactivity in Environmental Air at Los Alamos, 

New Mexico for 1970. LA-4661. Repos. No. 2167. 

Buckland, C.W. 1952. Air Sampling for Activity within and from Ten-Site Stacks (memorandum to 

D.D. Meyer, November 15, 1952). Los Alamos, New Mexico. Repos. No. 180. 

Graham, E. R. 1964. Strontium-90, CS-137, and Radioactive Rare Earths in Environmental Rain and Air 

at Los Alamos, New Mexico. 1958 – June 1963. LAMS-2878. Los Alamos, New Mexico. Repos. No. 

2184. 

Hanson W.C., 1973. Plutonium-239 Concentrations in Acid-Pueblo Canyons. Memo H8-73-207. Los 

Alamos, New Mexico, Repos. No. 272. 
14-30 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14

Johnson, W.S. 1954. Increase in Environmental Background of April 5, 1954 (memorandum to W.O. 

Whipple, April 7, 1954) Los Alamos, New Mexico. Repos. No. 960. 

Kennedy, W. R. 1948. Los Alamos Water Supply – Guaje Well No. 3 (memorandum to J. Bolton, 

September 9, 1948). Los Alamos, New Mexico. Repos. No. 218. 

Kennedy, W. R. 1952. Area Surveys – North of DP Sites (memorandum to T.M. White, February 21, 

1952). Los Alamos, New Mexico. Repos. No. 7687. 

Kennedy, W. R. 1958. Environmental Sampling (memorandum to T.L. Shipman, March 28, 1958). Los 

Alamos, New Mexico. Repos. No. 189. 

Kennedy, W. R. 1959. Air Sampling in the Los Alamos Community (memorandum to C.W. Richard, 

November 30, 1959). Los Alamos, New Mexico. Repos. No. 6457. 

Kennedy, W. R. 1960. Radioactivity in Environmental Air at Los Alamos, New Mexico for the Period 

November 17, 1958 through December 31, 1959. LAMS-2397. Repos. No. 2188. 

Kennedy, W. R. 1961a. Beta-Gamma Radioactivity in Environmental Air at Los Alamos, New Mexico, 

for 1st Quarter 1961. ER37183. Los Alamos, New Mexico. Repos. No. 614. 

Kennedy, W. R. 1961b. Beta-Gamma Radioactivity in Environmental Air at Los Alamos, New Mexico 

for 1960. LAMS-2499. Repos. No. 2187. 

Kennedy, W. R. 1962. Beta-Gamma Radioactivity in Environmental Air at Los Alamos, New Mexico for 

1961. LAMS-2702. Repos. No. 2186. 

Kennedy, W. R. 1965. Los Alamos Environmental Monitoring Program. Los Alamos, New Mexico. 

September 2, 1965 Repos. No. 3514. 

Kennedy 1971. Second quarter Radiochemical and Chemical Analyses for Water Samples Collected 

During the Period September 1969 through December 1970. Los Alamos, New Mexico, Repos. No. 764. 

Kennedy, W. R., W. D. Purtyman, H. F. Schulte, 1971, Los Alamos Environmental Monitoring Program, 

July through December 1970, LA-4672-MS. Los Alamos, New Mexico. Repos. No. 2178. 

Kingsley, W.H. 1947. Survey of Los Alamos and Pueblo for Radioactive Contamination and Radioassay 

Test Runs on Sewer Water Samples and Water and Soil Samples Taken from Los Alamos and Pueblo 

Canyons, February 20, 1947, LAMS-516. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. 

Repos. No. 3273. 

Kingsley, W.H., J.F. Tribby 1947. Survey of Los Alamos and Pueblo Canyons for Radioactive 

Contamination in May 1947, June 14, 1947, LAMS-516A. Los Alamos Scientific Laboratory, Los 

Alamos, New Mexico. Repos. No. 3274. 

LANL (Los Alamos National Laboratory), 1981. Environmental Surveillance at Los Alamos During 

1980.” Report LA-8810-ENV. Los Alamos, New Mexico. Repos. No. 930. 

LANL (Los Alamos National Laboratory), 1982. Environmental Surveillance at Los Alamos During 

1981. Report LA-9349-ENV. Los Alamos, New Mexico. Repos. No. 929. 

LANL (Los Alamos National Laboratory), 1983. Environmental Surveillance at Los Alamos During 

1982. Report LA-9762-ENV. Los Alamos, New Mexico. Repos. No. 1314. 

LANL (Los Alamos National Laboratory), 1984. Environmental Surveillance at Los Alamos During 

1983.” Report LA-10100-ENV. Los Alamos, New Mexico. Repos. No. 2342. 

LANL (Los Alamos National Laboratory), 1985. Environmental Surveillance at Los Alamos During 

1984.” Report LA-10421-ENV. Los Alamos, New Mexico. Repos. No. 654. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14 14-31

LANL (Los Alamos National Laboratory), 1986. Environmental Surveillance at Los Alamos During 

1985.” Report LA-10721-ENV. Los Alamos, New Mexico. Repos. No. 1319. 

LANL (Los Alamos National Laboratory), 1987. Environmental Surveillance at Los Alamos During 

1986.” Report LA-10992-ENV. Los Alamos, New Mexico. Repos. No. 4074. 

LANL (Los Alamos National Laboratory), 1988. Environmental Surveillance at Los Alamos During 

1987.” Report LA-11306-ENV. Los Alamos, New Mexico. Repos. No. 4075. 

LANL (Los Alamos National Laboratory), 1989. Environmental Surveillance at Los Alamos During 

1988.” Report LA-11628-ENV. Los Alamos, New Mexico. Repos. No. 4076. 

LANL (Los Alamos National Laboratory), 1990. Environmental Surveillance at Los Alamos During 

1989.” Report LA-12000-ENV. Los Alamos, New Mexico. Repos. No. 1088. 

LANL (Los Alamos National Laboratory), 1991. Environmental Surveillance at Los Alamos During 

1990.” Report LA-12271-ENV. Los Alamos, New Mexico. Repos. No. 2311. 

LANL (Los Alamos National Laboratory), 1992. Environmental Surveillance at Los Alamos During 

1991.” Report LA-12572-ENV. Los Alamos, New Mexico. Repos. No. 2189. 

LANL (Los Alamos National Laboratory), 1993. Environmental Surveillance at Los Alamos During 

1992.” Report LA-12764-ENV. Los Alamos, New Mexico. Repos. No. 1089. 

LANL (Los Alamos National Laboratory), 1994. Environmental Surveillance at Los Alamos During 

1993.” Report LA-12973-ENV. Los Alamos, New Mexico. Repos. No. 3903. 

LANL (Los Alamos National Laboratory), 1995. Environmental Surveillance at Los Alamos During 

1994.” Report LA-13047-ENV. Los Alamos, New Mexico. Repos. No. 3857. 

LANL (Los Alamos National Laboratory), 1996. Environmental Surveillance at Los Alamos During 

1995.” Report LA-13210-ENV. Los Alamos, New Mexico. Repos. No. 3849. 

LANL (Los Alamos National Laboratory), 1997. Environmental Surveillance at Los Alamos During 

1996.” Report LA-13343-ENV. Los Alamos, New Mexico. Repos. No. 4077 

LANL (Los Alamos National Laboratory), 1998. Environmental Surveillance at Los Alamos During 

1997.” Report LA-13487-ENV. Los Alamos, New Mexico. Repos. No. 3 and 3863. 

LANL (Los Alamos National Laboratory), 1999. Environmental Surveillance at Los Alamos During 

1998.” Report LA-13663-ENV. Los Alamos, New Mexico. Repos. No. 3892. 

LANL (Los Alamos National Laboratory), 2000. Environmental Surveillance at Los Alamos During 

1999.” Report LA-13775-ENV. Los Alamos, New Mexico. Repos. No. 3873. 

LANL (Los Alamos National Laboratory), 2001, Environmental Surveillance at Los Alamos During 

2000, LA-13861-ENV. Los Alamos, New Mexico. Repos. No. 3875. 

LANL (Los Alamos National Laboratory), 2002, Environmental Surveillance at Los Alamos During 

2001, LA-13979-ENV. Los Alamos, New Mexico. Repos. No. 6198. 

LANL (Los Alamos National Laboratory), 2003, Environmental Surveillance at Los Alamos During 

2002, LA-14085-ENV. Los Alamos, New Mexico. Repos. No. 6199. 

LANL (Los Alamos National Laboratory), 2004, Environmental Surveillance at Los Alamos During 

2003, LA-14162-ENV. Los Alamos, New Mexico. Repos. No. 6200. 

LANL (Los Alamos National Laboratory), 2005, Environmental Surveillance at Los Alamos During 

2004, LA-14239-ENV. Los Alamos, New Mexico. Repos. No. 6201. 
14-32 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14

LANL (Los Alamos National Laboratory), 2006, Environmental Surveillance at Los Alamos During 

2005, LA-14239-ENV. Los Alamos, New Mexico. Repos. No. 7989. 

LANL (Los Alamos National Laboratory), 2007. Environmental Surveillance at Los Alamos During 

2006, LA-14239-ENV. Los Alamos, New Mexico. Repos. No. 7990. 

LANL (Los Alamos National Laboratory), 2008, Environmental Surveillance at Los Alamos During 

2007, LA-14239-ENV. Los Alamos, New Mexico. Repos. No. 7991. 

LASL (Los Alamos Scientific Laboratory), 1948. H Division [Monthly] Progress Report, LAMS-783, 

July 20, 1948 - August 20, 1948, HSPT-REL-94-253. Los Alamos, New Mexico. Repos. No. 2258. 

LASL (Los Alamos Scientific Laboratory), 1949a, H Division Monthly Progress Report, LAMS 889, 

March 20, 1949 - April 20, 1949, HSPT-REL-94-260, Los Alamos, New Mexico. Repos. No. 2263. 

LASL (Los Alamos Scientific Laboratory), 1949b, H Division Monthly Progress Report, LAMS 901, 

April 20, 1949 - May 20, 1949, HSPT-REL-94-262, Los Alamos National Laboratory, Los Alamos, New 

Mexico Repos. No. 2264. 

LASL (Los Alamos Scientific Laboratory), 1949c, H Division Monthly Progress Report, LAMS 956, 

August 20, 1949 - September 20, 1949, HSPT-REL-94-306, Los Alamos, New Mexico. Repos. No. 2268. 

LASL (Los Alamos Scientific Laboratory), 1949d, H Division Monthly Progress Report, October 20, 

1949 - November 20, 1949, HSPT-REL-94-307, Los Alamos, New Mexico. Repos. No. 2271. 

LASL (Los Alamos Scientific Laboratory), 1950a. H Division Annual Report 1949, LA-1072, Los 

Alamos, New Mexico. Repos. No. 2270. 

LASL (Los Alamos Scientific Laboratory), 1950b, H Division Monthly Progress Report, May 20 - June 

20, 1950, HSPT-REL-94-290, Los Alamos, New Mexico. Repos. No. 2216. 

LASL (Los Alamos Scientific Laboratory), 1951. H Division Annual Report 1950, LA-1256, Los 

Alamos, New Mexico. Repos. No. 2224. 

LASL (Los Alamos Scientific Laboratory), 1952. H Division Annual Report 1951, LA-1425, Los 

Alamos, New Mexico. Repos. No. 2287. 

LASL (Los Alamos Scientific Laboratory), 1954a. Airborne Alpha Activity d m-1 m-3 Townsite and Air 

Sampling Station Locations, March – July, 1954. Unavailable report number. Los Alamos, New Mexico. 

Repos. No. 6739. 

LASL (Los Alamos Scientific Laboratory), 1954b. Airborne Contamination Tests, August – October, 

1954. Unavailable report number. Los Alamos, New Mexico. Repos. No. 6743. 

LASL (Los Alamos Scientific Laboratory), 1959. Ten Site Memos, 1956-1959. Unavailable Report 

number unavailable. Los Alamos, New Mexico. Repos. No. 160. 

LASL (Los Alamos Scientific Laboratory), 1961a. Beta-Gamma Radioactivity in Environmental Air at 

Los Alamos, 1st quarter, 1961. Los Alamos, New Mexico. Repos. No. 614. 

LASL (Los Alamos Scientific Laboratory), 1961b. Environmental Monitoring Report Program 1960 

Summary. ER 37224. Repos. No. 609. 

LASL (Los Alamos Scientific Laboratory), 1971a. Environmental Monitoring Program – January – June 

1970. Report LA-4871-MS. Los Alamos, New Mexico. Repos. No. 1000. 

LASL (Los Alamos Scientific Laboratory), 1971b. Environmental Monitoring Program – July through 

December 1970. Report LA-4672-MS. Los Alamos, New Mexico. Repos. No. 2178. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14 14-33

LASL (Los Alamos Scientific Laboratory), 1972a. Environmental Monitoring in the Vicinity of the Los 

Alamos Scientific Laboratory – January through June 1971. Report LA-4871-MS. Los Alamos, New 

Mexico. Repos. No. 2156 and 4079. 

LASL (Los Alamos Scientific Laboratory), 1972b. Environmental Monitoring in the Vicinity of the Los 

Alamos Scientific Laboratory – July through December 1971. Report LA-4970. Los Alamos, New 

Mexico. Repos. No. 2155 and 4079. 

LASL (Los Alamos Scientific Laboratory), 1973. Environmental Monitoring in the Vicinity of the Los 

Alamos Scientific Laboratory – Calendar Year 1972. Report LA-5184. Los Alamos, New Mexico. 

Repos. No. 887. 

LASL (Los Alamos Scientific Laboratory), 1974. Environmental Surveillance at Los Alamos During 

1973. Report LA-5586. Los Alamos, New Mexico. Repos. No. 2161. 

LASL (Los Alamos Scientific Laboratory), 1975. Environmental Surveillance at Los Alamos During 

1974. Report LA-5977-PR. Los Alamos, New Mexico. Repos. No. 2133. 

LASL (Los Alamos Scientific Laboratory), 1976a. Environmental Surveillance at Los Alamos During 

1975. Report LA-6321-MS. Los Alamos, New Mexico. Repos. No. 2158. 

LASL (Los Alamos Scientific Laboratory), 1976b. LANL Meteorological Data from 1956 to 1971. Los 

Alamos, New Mexico. Repos. No. 126. 

LASL (Los Alamos Scientific Laboratory), 1977. Environmental Surveillance at Los Alamos During 

1976. Report LA-6901-MS. Los Alamos, New Mexico. Repos. No. 2159. 

LASL (Los Alamos Scientific Laboratory), 1978. Environmental Surveillance at Los Alamos During 

1977. Report LA-7263-MS. Los Alamos, New Mexico. Repos. No. 2069. 

LASL, 1978b. Draft, Radiological Resurvey and Evaluation of Bayo Canyon. Los Alamos, New Mexico. 

Repos. No. 877. 

LASL (Los Alamos Scientific Laboratory), 1979. Environmental Surveillance at Los Alamos During 

1978.” Report LA-7800-ENV. Los Alamos, New Mexico. Repos. No. 953. 

LASL (Los Alamos Scientific Laboratory), 1980. Environmental Surveillance at Los Alamos During 

1979. Report LA-8200-ENV. Los Alamos, New Mexico. Repos. No. 2190. 

NIOSH (National Institute for Occupational Safety and Health), 2004. Technical Basis Document for the 

Oak Ridge National Laboratory – Environmental Dose, Document number ORAUT-TKBS-0012-4. 

NIOSH Dose Reconstruction Project under the EEOICPA. May 7, 2004. Repos. No. pending. 

Parker, H.M. 1974. Brief Review of the LASL Environmental Surveillance Program. Battelle Northwest 

Laboratories. 

Rogers M. 1978. History and Environmental Setting at LASL Near-Surface Land Disposal Facilities for 

Radioactive Wastes. Volumes 1 and 2, Report LA-6848-MS. Los Alamos, New Mexico. Repos. No. 

3115 and 3116. 

Schnap B.F., Tribby J.F., 1948a. Radioassay and Spectrochemical Analysis of Water and Soil Samples 

Collected from Los Alamos and Pueblo Canyons and Analyses of Water Samples from Tech Area, DP 

Site, and Laundry Drains, December 1947. Los Alamos Scientific Laboratory, Los Alamos, New 

Mexico. Repos. No. 218. 

Schnap B.F. 1948b. Monthly Report for Nov. 20 – Dec. 20, 1948 (Water Sample Results). Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. December 20, 1948. Repos. No. 218. 

Shipman, T. L. 1953. H Division Annual Report 1952, HSPT-REL-94-313, LA-1538, Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 2275. 
14-34 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 14

Shipman T. L. 1956. Environmental Studies, Tuft Studies, and Cyanide Waste, June 27, 1956. Los 

Alamos, New Mexico. Repos. No. 6993. 

Shipman, T. L., 1958. Annual Report, Health Division 1957, HSPT-REL-94-451, LA-,2216 Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico Repos. No. 2392. 

Shipman, T. L. 1962. LASL H-Division Progress Report, November 21 – December 20, 1962, Group H6, Environmental Radiation. Los Alamos, New Mexico. Repos. No. 4951. 

Shipman, T. L. 1963a. LASL H-Division Progress Report, December 21, 1962 – January 20, 1963, Group 

H-6, Environmental Radiation. Los Alamos, New Mexico. Repos. No. 2499. 

Shipman, T. L. 1963b. LASL H-Division Progress Report, January 21 – February 20, 1963, Group H-6, 

Environmental Radiation. Los Alamos, New Mexico. Repos. No. 2500. 

Shipman, T. L. 1963c. LASL H-Division Progress Report, February 21 – March 20, 1963, Group H-6, 

Environmental Radiation. Los Alamos, New Mexico. Repos. No. 2501. 

Shipman, T. L. 1963d. LASL H-Division Progress Report, March 21 - April 20, 1963, Group H-6, 

Environmental Radiation. Los Alamos, New Mexico. Repos. No. 2536. 

Shipman, T. L. 1963e. LASL H-Division Progress Report, April 21 - May 20, 1963, Group H-6, 

Environmental Radiation. Los Alamos, New Mexico. Repos. No. 2537. 

Shipman, T. L. 1963f. LASL H-Division Progress Report, May 21 - June 20, 1963, Group H-6, 

Environmental Radiation (W. R. Kennedy, Leader). Repos. No. 2538. 

Shipman, T. L. 1963g. LASL H-Division Progress Report, June 21 - July 20, 1963, Group H-6, 

Environmental Radiation (W. R. Kennedy, Leader). Repos. No. 2539. 

Shipman, T. L. 1963h. LASL H-Division Progress Report, July 21 - August 20, 1963, Group H-6, 

Environmental Radiation (W. R. Kennedy, Leader). Repos. No. 2540. 

Shipman, T. L. 1963i. LASL H-Division Progress Report, August 21 - September 20, 1963, Group H-6, 

Environmental Radiation (W. R. Kennedy, Leader). Repos. No. 2541. 

Shipman, T. L. 1963j. LASL H-Division Progress Report, September 21 - October 20, 1963, Group H-6, 

Environmental Radiation (W. R. Kennedy, Leader). Repos. No. 4952. 

Shipman, T. L. 1963k. LASL H-Division Progress Report, October 21 - November 20, 1963, Group H-6, 

Environmental Radiation (W. R. Kennedy, Leader). Repos. No. 2502. 

Steinhardt R.G. 1945. Summary of Health Conditions of the RaLa Program (memorandum) June 28, 

1945. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 676. 

Tribby, J.F. 1945. Report on the Contamination of Creek Water. October 15, 1945. Los Alamos 

Scientific Laboratory, Los Alamos, New Mexico. Repos. No. 230. 

Tribby, J.F. 1947. The Canyon Problem at Los Alamos. Los Alamos Scientific Laboratory, Los Alamos, 

New Mexico. Repos. No. 273. 

Tribby, J.F. 1948. Report on Radioactive Tolerances for Waste Effluents and Waste Gases and 

Radioactive Dusts, February 17, 1948. LAMS-689. Los Alamos Scientific Laboratory, Los Alamos, 

New Mexico. Repos. No. 2345 and 3107. 

USGS, 1961. USGS Water Samples – December, 1960. Los Alamos Scientific Laboratory, Los Alamos, 

New Mexico. Repos. No. 767. 

Williams, S.J. 1948. Report of the Safety and Industrial Health Board. National Safety Council, April, 

1948. Repos. No. 2944. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 15-1 

Chapter 15: Development of Residential Areas 

 Around Los Alamos 

For a radionuclide or chemical that was used at Los Alamos to have posed a health hazard to members of 

the public, each of the following elements must have existed: 

• A contaminant source that released the material into the environment, 

• A transport medium that carried the contaminant off site to a location where exposure took 

place (the most common media being air and water), and 

• An exposure route through which the contaminant entered an individual’s body to produce 

adverse health effects. Examples of exposure routes include inhalation, ingestion, and immersion 

in airborne contamination. 

Evaluation of off-site exposures from activities at Los Alamos technical areas will require documentation 

of the development of nearby residential areas over time. While it was initially thought that the 31 houses 

commandeered from the Los Alamos Ranch School and Anchor Ranch would provide sufficient housing 

for the projected staff of 30 scientists and their families (Martin 2000), it soon became clear that the scope 

of the challenge to provide housing for Los Alamos residents had been severely underestimated. The 

scarcity of housing in Los Alamos was problematic during World War II and for years to follow. Hiring 

at the Lab was at times severely restricted because there was nowhere for new employees to live. This 

pressure to provide housing and the limited availability of suitable land in the region of finger-like mesas 

and canyons led to the development of housing that in some cases was much closer to operational areas 

than has become customary for government facilities that undertake processing of nuclear materials and 

high explosives and/or operation of devices such as reactors or high-energy particle accelerators. 

Development of Housing Areas in Los Alamos 

In response to the atomic weapons race of WWII, Los Alamos, New Mexico, home of the Los Alamos 

Ranch School, was chosen as the location of key Manhattan Project operations in 1943. Initially, the 54 

buildings of the private school for boys (27 of which were houses) were thought to be satisfactory to 

house the projected staff of scientist and their families (Hunner 2004; Martin 2000). Soon after the 

project began, the need for further housing was inevitable, and construction of the Sundt apartments 

began to the west and north of the Ranch School buildings (Martin 2000). The population of Los Alamos 

continued to grow during 1944 and 1945, and in response, several temporary housing developments were 

erected in the vicinity of the original town site. 
15-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 

The LAHDRA Project Reference Map provided with this report shows the different residential areas of 

Los Alamos and depicts the periods of their development, the periods they remained in use, and allows 

one to see the proximity of the different housing areas to operational areas of potential interest. The 

original Technical Area (TA-1) and wartime and early postwar housing in Los Alamos are shown in 

Figure 15-1, which is also included as an inset map in the Project Reference Map. 

With the success of the Trinity Test in July 1945 and the ultimate ending of WWII in the September that 

followed, the original mission of the Manhattan Project was accomplished (Martin 2000). Many scientist 

and their families, unsure of the future of Los Alamos, returned to pre-war careers and lives in different 

locations. In 1946 over 1,000 residents left the town of Los Alamos (Hunner 2004). The temporary 

housing constructed during the war was deteriorating, and, in 1946, the laboratory began developing the 

first permanent housing in the Western Area of Los Alamos to encourage the residents to remain in the 

town (Martin 2000; Hunner 2004). After realizing that the Los Alamos Laboratory was going to be a 

permanent location for research, turnover slowed and hiring increased (LASL 1956). Expansion of the 

Western Area and town site continued through the late 1940s in response to overcrowding. The 

population in Los Alamos grew from approximately 7,000 people in 1947 to over 8,500 people in 1949 

(Hunner 2004). The main areas of residential development in Los Alamos from 1946 through 2000 are 

shown in Fig. 15-2. 

As a result of President Truman’s decision to further research on the creation of the hydrogen bomb in 

1949, significant amounts of money flowed into Los Alamos to support new laboratory research and 

handle the arrival of new personnel (Hunner 2004). The population grew from slightly over 8,500 in 

1949 to 12,800 by 1952 (Hunner 2004). Residential areas began to expand northward into the North 

Community, and expansion continued into the early 1950s. Temporary housing constructed during the 

war years began to be replaced with permanent housing in the mid 1950s (LASL 1956; Martin 2000). 

The Los Alamos laboratory facilities began to be moved from the Ashley Pond area to the South Mesa. 

To support the necessary construction crews and their families, in 1949, White Rock construction camp 

was erected on a level plain near the rim of White Rock Canyon and Totavi trailer camp was erected on 

San Ildefonso Pueblo land to the east of Los Alamos along New Mexico Highway 502 (Martin 1998, 

2000; Hunner 2004). Both camps were short-lived, however, White Rock nearly closing by 1953 and 

entirely shutting down in 1957 and Totavi shutting down in 1953 (Martin 1998, 2000). 

The government maintained ownership of all property in Los Alamos until 1958, when Barranca Mesa 

was opened for private ownership on the mesa north of Bayo Canyon (Martin 2000). Development 

continued on Barranca Mesa through the mid-1960s and continued growth forced expansion onto the 
Figure 15-1: The original Los Alamos Technical Area (lower left corner) and wartime a
15-4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 
Figure 15-2: Main residential areas of Los Alamos

[mesa-top areas (above) and White Rock area (right)] 

Detail of the area in the rectangle shown above around the 

center of Los Alamos townsite is shown in Figure 1 for the 

wartime and early postwar period. 

Maps are from the LAHDRA Project Reference Map produced by 

cARTography by Andrea Kron. Data source: LANL GISLab. 
15-6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 15-7 

narrow neck of the mesa in the late 1970s and early 1980s (Martin 2000). The area of White Rock reopened to house low-income families in 1962, and growth continued throughout the 1960s and 1970s 

(Marin 2000). To accommodate the seemingly continuous shortage of housing, construction on the North 

Mesa began for both subdivisions and mobile home parks in 1977 (Martin 2000). 

Following several years of rapid development, Los Alamos experienced relatively slow growth 

throughout the 1980s (Martin 2000). New construction returned in the mid-1990s with the development 

of Ponderosa Estates near the Guaje Pines Cemetery in the northern part of the town. In 2000, the 

devastating Cerro Grande Fire destroyed over 400 homes in the Western Area and North Community 

(Martin 2000). Rebuilding of the burned areas continues today and new developments, such as the 

Quemazon Community in the northwest area of town, are being erected (Kron, personal communication). 

Locations of Interest When Considering Historical Operations 

Based on reviews of historical documents performed to date, the following locations are among the sites 

where historical operations took place that appear to warrant evaluation in terms of potential off-site 

releases or health effects: 

• D-Building at the original technical area (TA-1) 

• DP West (TA-21; with released primarily from Building 12 stacks) 

• DP East (TA-21; with released primarily from Buildings 152 and 153) 

• Omega Site Reactors (TA-2) 

• TA-3, the current main Technical Area 

• The LAMPF (now LANSCE) accelerator complex 

• High explosives manufacturing areas (example used is S-Site, TA-16) 

• High Explosives firing sites (example used is R-Site, TA-15) 

• Bayo Canyon firing site (TA-10, site of radioactive lanthanum test shots) 

For evaluation of potential health effects from historical releases, each of these locations should be 

evaluated with regard to its relationship to Los Alamos housing areas and public facilities that were 

occupied during time periods that correspond to periods when operations of interest were also active. 

Philomena’s restaurant, which began operating in the late 1970s, has been an area of interest due to its 

proximity to the LAMPF (now LANSCE) facility. Although not a Los Alamos housing area, San 

Ildefonso Pueblo land is also considered due to its close proximity to LANL operations. The housing 

areas and public facilities that will be most important for a given location of operations depend on a 

number of factors, including: 
15-8 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 

• The distance from the contaminant source to the housing area, 

• The direction from the contaminant source to the housing area, and 

• The prevalence of winds from the contaminant source towards the housing area. 

Detailed dose assessment typically utilizes air dispersion modeling based on actual locations of release 

points and potentially exposed people, using meteorological data that reflect any diurnal or seasonal 

variations in air flow patterns. As preliminary indicators of residential areas that may be of concern, 

however, it is useful to examine distance, direction, and wind prevalence for relevant source-receptor 

combinations. 

A 16-sector wind direction frequency distribution based on LANL measurements over a ten-year period 

was used to determine the prevalence of winds from release points of interest towards housing areas and 

public facilities. That wind frequency distribution is shown in Table 15-1. This table reflects a wide 

variation in wind direction when all data are included. If you look instead at data from specific times of 

the day, you will see that there are recognizable diurnal air flow patterns. As observed in many 

mountainous areas, air flow is typically up-valley during the day (as solar heating causes air to rise) and 

down-valley at night (as cooling air drains to lower elevations). These patterns are not seen in the general 

wind direction data shown in Table 15-1, but they are important to consider when evaluating releases that 

may have only occurred during daylight hours versus those that may have occurred around the clock. 

Tables 15-2 through 15-10 summarize information that will be relevant to evaluation of the potential 

importance of public areas when evaluating releases from the identified locations of interest. In instances 

where the operational location of interest is large or had numerous release points, the distance was 

measured from the middle of the complex. This was necessary with the current main technical area (TA3) and LAMPF (now LANSCE). Distance was measured in increments of 0.25 mile and always rounded 

down to the closer distance if a point fell between two distances. In most cases, the distance between the 

location of interest and the various public areas is presented as a range from the closest to the farthest 

possible points. Direction, however, was determined by using the public area closest to the location of 

interest. 

Housing areas that are not relevant to operations of a particular facility, that is, they did not exist when 

that facility was operational, are shown in gray in Tables 2 through 10 rather than black to indicate that 

residential exposures were not possible. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 15-9 

Due to its close proximity to LANL operations, San Ildefonso Pueblo land is also considered an area of 

interest. The vast lands make it necessary to determine the areas of land that were historically used for 

residential purposes. Traditionally, Pueblo members lived near their central plaza and had fields which 

they tended outside of this area (ChemRisk 2006). According to a 1953 USGS map of Espanola, New 

Mexico, the nearest concentration of San Ildefonso Pueblo people to Los Alamos was north of the current 

Highway 502 and east of the Rio Grande (ChemRisk 2006). 

Table 15-1. Wind direction frequency distribution based on 10 years of LANL data 

Sector Wind from Wind towards Percentage 

1 N S 3.4233 

2 NNE SSW 3.6218 

3 NE SW 3.3293 

4 ENE WSW 3.1224 

5 E W 3.4616 

6 ESE WNW 3.3936 

7 SE NW 3.718 

8 SSE NNW 6.0108 

9 S N 8.8439 

10 SSW NNE 8.2649 

11 SW NE 7.7308 

12 WSW ENE 8.1937 

13 W E 11.4148 

14 WNW ESE 11.9399 

15 NW SE 9.2887 

16 NNW SSE 4.2424 
15-10 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 

Table 15-3: DP West Site at TA-21 (operational from 1945 to 1973) 

Public Area Period Occupied Distance from 

DP West (mi) 

Direction from 

DP West 

Winds in this 

direction (%) 

Wartime Housing 1943-1945 0.75-2 WNW 3.4 

Early Postwar Housing 1946-1960s 0.5-2.5 NW 3.7 

Western Area 1946-present 2.25-2.75 WNW 3.4 

North Community 1948-present 1.75-3.25 NW 3.7 

Replacement Housing 1953-present 0.5-2.25 WNW 3.4 

Group 18 Homes by Airport 1957-present 0.25-0.5 NNW 6.0 

Barranca Mesa 1958-present 1.5-2.25 N 8.8 

Royal Crest Trailer Park 1960-present 0.75 SW 3.3 

North Mesa 1977-present 0.75-1.75 NNW 6.0 

Otowi Mesa Expansion late 1970s-present 1.5-1.75 NE 7.7 

Ponderosa Estates Mid 1990s-present 2-2.5 NNW 6.0 

East Gate / Philomena’s Late 1970s-present 1.25 E 11.4 

Totavi Camp 1949-1953 5.5 E 11.4 

White Rock Camp 1949-1953 (1957) 5.25 SE 9.3 

White Rock Community 1962-present 5-7 SE 9.3 

San Ildefonso Pueblo Lands 1598-present 9 ENE 8.2 

Table 15-2: D-Building at the Original Technical Area (operational from 1943 to 1953)

Public Area Period Occupied Distance from D 

Building (mi) 

Direction from 

D Building 

Winds in this direction 

(%) 

Wartime Housing 1943-1945 0.1-0.75 NW 3.7 

Early Postwar Housing 1946-1960s 0.25-1 NE 7.7 

Western Area 1946-present 0.25-1.5 WNW 3.4 

North Community 1948-present 0.75-2 NW 3.7 

Replacement Housing 1953-present 0.25-0.75 NE 7.7 

Group 18 Homes by Airport 1957-present 0.75-1.25 ENE 8.2 

Barranca Mesa 1958-present 1.5-2.5 NNE 8.3 

Royal Crest Trailer Park 1960-present 0.75 SE 9.3 

North Mesa 1977-present 0.75-2.25 NNE 8.3 

Otowi Mesa Expansion late 1970s-present 2.25-3 NE 7.7 

Ponderosa Estates Mid 1990s-present 1.5-2 N 8.8 

East Gate / Philomena’s Late 1970s-present 2.25 E 11.4 

Totavi Camp 1949-1953 7 E 11.4 

White Rock Camp 1949-1953 (1957) 6.25-7 SE 9.3 

White Rock Community 1962-present 5.75-8 SE 9.3 

San Ildefonso Pueblo Lands 1598-present 10.25 E 11.4 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 15-11 

Table 15-5: Omega Site Reactors at TA-2 (operational from 1943 To 1992) 

Public Area Period Occupied Distance from 

Omega Site (mi) 

Direction from 

Omega Site 

Winds in this direction 

(%) 

Wartime Housing 1943-1945 0.25-1.25 WNW 3.4 

Early Postwar Housing 1946-1960s 0.25-1.75 N 8.8 

Western Area 1946-present 1.5-2.25 WNW 3.4 

North Community 1948-present 1.25-2.25 NW 3.7 

Replacement Housing 1953-present 0.25-0.75 N 8.8 

Group 18 Homes by Airport 1957-present 0.5-0.75 NE 7.7 

Barranca Mesa 1958-present 1.75-2.25 NNE 8.3 

Royal Crest Trailer Park 1960-present 0.25 S 3.4 

North Mesa 1977-present 1-1.5 N 8.8 

Otowi Mesa Expansion late 1970s-present 2-2.5 NE 7.7 

Ponderosa Estates Mid 1990s-present 1.75-2.25 NNW 6.0 

East Gate / Philomena’s Late 1970s-present 1.75 E 11.4 

Totavi Camp 1949-1953 6.25 E 11.4 

White Rock Camp 1949-1953 (1957) 5.75 SE 9.3 

White Rock Community 1962-present 5.25-7.25 SE 9.3 

San Ildefonso Pueblo Lands 1598-present 8.5 ENE 8.2 

Table 15-4: DP East Site at TA-21 (operational from 1945 to 1970) 

Public Area Period Occupied Distance from DP 

East (mi) 

Direction from 

DP East 

Winds in this direction 

(%) 

Wartime Housing 1943-1945 1.25-2.25 WNW 3.4 

Early Postwar Housing 1946-1960s 1-2.75 WNW 3.4 

Western Area 1946-present 2.75-3.25 WNW 3.4 

North Community 1948-present 2-3.75 NW 3.7 

Replacement Housing 1953-present 1-2.75 WNW 3.4 

Group 18 Homes by Airport 1957-present 0.5-0.75 NW 3.7 

Barranca Mesa 1958-present 1.5-2.25 NNW 6.0 

Royal Crest Trailer Park 1960-present 1 WSW 3.1 

North Mesa 1977-present 0.75-2.25 NNW 6.0 

Otowi Mesa Expansion late 1970s-present 1.5 NNE 8.3 

Ponderosa Estates Mid 1990s-present 2.25-3 NNW 6.0 

East Gate / Philomena’s Late 1970s-present 0.75 E 11.4 

Totavi Camp 1949-1953 5 E 11.4 

White Rock Camp 1949-1953 (1957) 5 SE 9.3 

White Rock Community 1962-present 4.5-7 SE 9.3 

San Ildefonso Pueblo Lands 1598-present 8.25 ENE 8.2 
15-12 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 

Note – Distance from TA-3 is measured from middle of complex 

Table 15-7: LAMPF (now LANSCE, operational from 1968 to present) 

Public Area Period Occupied 

Distance from 

LAMPF Building 

(mi) 

Direction from 

LAMPF 

Building 

Winds in this direction 

(%) 

Wartime Housing 1943-1945 2-3 WNW 3.4 

Early Postwar Housing 1946-1960s 1.75-3.5 WNW 3.4 

Western Area 1946-present 3.25-4 WNW 3.4 

North Community 1948-present 2.75-4.25 NW 3.7 

Replacement Housing 1953-present 1.75-3.5 NW 3.7 

Group 18 Homes by Airport 1957-present 1.25-1.75 NW 3.7 

Barranca Mesa 1958-present 2.25-3.25 NNW 6.0 

Royal Crest Trailer Park 1960-present 1.75 W 3.5 

North Mesa 1977-present 1.25-3 NNW 6.0 

Otowi Mesa Expansion late 1970s-present 1.75-2.25 N 8.8 

Ponderosa Estates Mid 1990s-present 3.25-3.75 NW 3.7 

East Gate / Philomena’s Late 1970s-present 0.5 NNE 8.3 

Totavi Camp 1949-1953 4.5 E 11.4 

White Rock Camp 1949-1953 (1957) 4 SE 9.3 

White Rock Community 1962-present 3.75-6 SE 9.3 

San Ildefonso Pueblo Lands 1598-present 8 ENE 8.2 

Note – Distance from LANSCE building is measured from middle of complex 

Table 15-6: TA-3, the current main technical area (operational from 1953 to present) 

Public Area Period Occupied Distance from 

TA-3 (mi) 

Direction from 

TA-3 

Winds in this 

direction (%) 

Wartime Housing 1943-1945 0.75-1.75 NE 7.7 

Early Postwar Housing 1946-1960s 1-2 NE 7.7 

Western Area 1946-present 0.5-1 N 8.8 

North Community 1948-present 1.25-2.25 N 8.8 

Replacement Housing 1953-present 0.5-2 NE 7.7 

Group 18 Homes by Airport 1957-present 2-2.5 ENE 8.2 

Barranca Mesa 1958-present 2.25-3.5 NE 7.7 

Royal Crest Trailer Park 1960-present 1.75 E 11.4 

North Mesa 1977-present 1.75-3.25 NE 7.7 

Otowi Mesa Expansion late 1970s-present 3.5-4 NE 7.7 

Ponderosa Estates Mid 1990s-present 2-2.5 NNE 8.3 

East Gate / Philomena’s Late 1970s-present 3.5 E 11.4 

Totavi Camp 1949-1953 8 E 11.4 

White Rock Camp 1949-1953 (1957) 7.25 SE 9.3 

White Rock Community 1962-present 6.5-9 SE 9.3 

San Ildefonso Pueblo Lands 1598-present 11.5 ENE 8.2 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 15-13 

Table 15-8: High Explosives Manufacturing Area– S-Site (TA-16, operational 1944 to present) 

Public Area Period Occupied Distance from SSite (mi) 

Direction from 

S-Site Building 

Winds in this direction 

(%) 

Wartime Housing 1943-1945 3-3.75 NNE 8.3 

Early Postwar Housing 1946-1960s 3.25-3.75 NNE 8.3 

Western Area 1946-present 2.75-3.25 NNE 8.3 

North Community 1948-present 3.5-4.25 N 8.8 

Replacement Housing 1953-present 3-3.75 NNE 8.3 

Group 18 Homes by Airport 1957-present 3.75-4 NE 7.7 

Barranca Mesa 1958-present 4.75-5.25 NE 7.7 

Royal Crest Trailer Park 1960-present 3 NE 7.7 

North Mesa 1977-present 3.75-4.75 NNE 8.3 

Otowi Mesa Expansion late 1970s-present 5.25-5.75 NE 7.7 

Ponderosa Estates Mid 1990s-present 4.25-4.75 NNE 8.3 

East Gate / Philomena’s Late 1970s-present 4.75 NE 7.7 

Totavi Camp 1949-1953 9.5 ENE 8.2 

White Rock Camp 1949-1953 (1957) 7-7.5 ESE 11.9 

White Rock Community 1962-present 6.25-8 ESE 11.9 

San Ildefonso Pueblo Lands 1598-present 12.5 ENE 8.2 

Table 15-9: High Explosive Firing Site – R-Site (TA-15, operational from 1944 to present) 

Public Area Period Occupied Distance from RSite (mi) 

Direction from 

R-Site Building 

Daytime Winds in this 

direction (%) 

Wartime Housing 1943-1945 2.5-3 N 8.8 

Early Postwar Housing 1946-1960s 2.5-3.25 NNE 8.3 

Western Area 1946-present 2.5-3.5 NNW 3.4 

North Community 1948-present 3.25-4.25 N 8.8 

Replacement Housing 1953-present 2.5-3 NNE 8.3 

Group 18 Homes by Airport 1957-present 2.75-3 NNE 8.3 

Barranca Mesa 1958-present 4-4.5 NNE 8.3 

Royal Crest Trailer Park 1960-present 2 NNE 8.3 

North Mesa 1977-present 3.25-3.75 N 8.8 

Otowi Mesa Expansion late 1970s-present 4.25-4.5 NNE 8.3 

Ponderosa Estates Mid 1990s-present 3.75-4.25 N 8.8 

East Gate / Philomena’s Late 1970s-present 3.5 NE 7.7 

Totavi Camp 1949-1953 7.5 ENE 8.2 

White Rock Camp 1949-1953 (1957) 5.25-6.25 ESE 11.9 

White Rock Community 1962-present 4.75-6.25 ESE 11.9 

San Ildefonso Pueblo Lands 1598-present 10.5 ENE 8.2 
15-14 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 

Based on examination of the information presented in Tables 15-2 through 15-10 and information from 

historical documents reviewed by the LAHDRA project team, following are discussions of public areas 

that may be of importance for evaluation of releases from the historical operations of interest listed above: 

a. D Building at TA-1 

D Building at the original Technical Area was the site of plutonium processing during the war years. 

Specifically, D Building housed plutonium purification and recovery, conversion to metal, metallurgy, 

weapon component fabrication, and application of coatings. After DP West site became operational in 

late 1945, D Building continued to house activities that involved plutonium, including chemical and 

metallurgical research and analysis, until a “new D Building” was completed on South Mesa in the form 

of the CMR Building within Technical Area 3 (Coffinberry and Miner 1961). D Building was razed in 

1953 (Ahlquist et al. 1977). 

Due to D Building’s period of operation and proximity to the town site, Wartime Housing and Early 

Postwar Housing would be public areas of interest with regards to historical releases from D Building. 

Wartime housing ranged from 0.1-0.75 miles from D Building, and the closest occupants were northwest 

of the D-Building in the Sundt apartments. Wind blew in the northwest direction 3.7% of the time 

averaged over a 10 year period. Early Postwar Housing ranged from 0.25 (Hanford Houses) to 1 mile 

(Denver Steel and Ft. Leonard Wood Houses) to the northeast of D Building, with the wind blowing to 

the northeast 7.7% of the time. Figures 15-3, 15-4, and 15-5 show the original Technical Area with 

wartime housing in the form of Sundt apartments located nearby. 

Public Area Period Occupied 

Distance from 

Bayo Canyon 

Firing Site (mi) 

Direction from 

Bayo Canyon 

Firing Site 

Winds in this 

direction (%) 

Wartime Housing 1943-1945 2-3 WSW 3.1 

Early Postwar Housing 1946-1960s 1.5-2.5 WSW 3.1 

Western Area 1946-present 3.25-4 WSW 3.1 

North Community 1948-present 2.5-4 W 3.5 

Replacement Housing 1953-present 1.75-3.25 WSW 3.1 

Group 18 Homes by Airport 1957-present 1.25-1.75 SW 3.3 

Barranca Mesa 1958-present 0.75-2.25 NW 3.7 

Royal Crest Trailer Park 1960-present 2.25 SW 3.3 

North Mesa 1977-present 0.5-2.25 WSW 3.1 

Otowi Mesa Expansion late 1970s-present 0.25-0.75 N 8.8 

Ponderosa Estates Mid 1990s-present 2.5-3 WNW 3.4 

East Gate / Philomena’s Late 1970s-present 1 S 3.4 

Totavi Camp 1949-1953 5 ESE 11.9 

White Rock Camp 1949-1953 (1957) 5.25 SSE 4.2 

White Rock Community 1962-present 5-7.25 SSE 4.2 

San Ildefonso Pueblo Lands 1598-present 8 E 11.4 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 15-15 

 

Figure 15-3: This November 1946 aerial photograph, looking south, shows Sundt apartments west (to the right) of 

the Technical Area, on both sides of Trinity Drive, which crosses from the upper left to the lower right of the photo. 

Photo courtesy Los Alamos Historical Society (LAHM-P1990-40-1-3028).

Nearest Sundt apartments 

C Building

D Building

Nearest Sundt 

apartments D Building

 Figure 15-4: This 12/04/1946 aerial photograph, looking north, shows the Sundt apartments (dark buildings in upper left) 

immediately west and north of the Technical Area. The large building at the lower right is D Building. The largest white 

Technical Area building nearest the Sundt Apartments (photo upper center) is C Building, which housed shops and was the 

site of a January 1945 fire that prompted planning of replacement facilities for processing plutonium. Photo courtesy Los 

Alamos Historical Society (LAHM-P1990-40-1-3029). 
15-16 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 

b. DP West (TA-21; with releases from Building 12 stacks) 

In response to fire hazard and safety concerns, most plutonium processing operations moved to DP West 

in late 1945. Building 12 was the filter building for all of the plutonium processing buildings (2, 3, 4, and 

5) and continued in service until 1973. A public area of interest with regard to releases from Building 12 

stacks is the Group 18 Housing west of the airport. Figures 15-6 and 15-7 show the locations of DP Site 

and relevant housing areas. The closest of these homes were 0.25 mi from DP West and winds blew in 

their direction (NNW) an average of 6.0% of the time. Other Los Alamos housing areas of interest 

include Early Postwar Housing such as the Denver Steel, Ft. Leonard Wood, Hanford, and Wingfoot 

housing developments. These areas were located 0.5 to 2.5 mi northwest of DP West, and winds blew in 

this direction 3.7% of the time. The trailer park south of DP Road should be considered since it was 

located 0.5 mi directly west from DP West, and winds blew in this direction 3.5% of the time. Finally, 

the Replacement Housing (see symbol C in Fig. 15-6), is an area of interest since it was constructed as 

close as 0.5 miles west-northwest of DP West, and wind blew in this direction 3.4% of the time. 

Fig. 15-5: Location of D Building within the original Technical Area relative to some Los Alamos wartime and 

early postwar housing. Sundt apartments are in the upper-left portion of the figure. The green buildings are 

administrative and service buildings, not residents. From a map produced by Barry Moore for the Los Alamos 

Historical Society and modified by cARTography by Andrea Kron. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 15-17 

c. DP East (TA-21; with releases from Buildings 152 and 153) 

DP East started up in 1945 and processed polonium and actinium and to produce initiators. Building 153 

served as the exhaust building for DP East until it shut down in 1970. A public area for consideration in 

relation to DP East operations is Group 18 Housing by the airport (see Figures 15-6 and 15-7). These 

homes were 0.5 to 0.75 miles northwest of DP East, and the wind blew in their direction approximately 

3.7% of the time. Before the housing by the airport was established, Wartime and Early Postwar 

Housing, and Replacement Housing would be areas for consideration. The trailer park south of DP Road 

was approximately 0.9-mile WNW of DP East, and the wind blows in that direction 3.4% of the time. 

d. Omega Site Reactors 

Omega Site was established in 1943 and has housed three different reactors: the Water Boilers (three 

versions), the Plutonium Fast Reactor, and the Omega West Reactor. Due to the perceived danger of the 

work to be performed, Omega Site was built at the bottom of Los Alamos Canyon away from the original 

Technical Area (Hunner 2004; SWEIS 1998). Initially, a flexible off-gas line carried reactor effluents 

from the bottom of the canyon to the top of South Mesa for discharge (LAMD-155 1947). In later years, 

a more conventional stack was built on top of South Mesa. Royal Crest Trailer Park, which sits on South 

Mesa 0.25 miles south of Omega Site, and the trailer park just south of DP Road, which from around 

1948 through 1963 was situated on Los Alamos Mesa directly above Omega Site, are potential public 

areas of consideration for the Omega Site releases (see Figures 15-8 and 15-9). 

Figure 15-6: Location of DP Site relative to LANL housing areas. Group 18 housing west of the airport (housing 

symbol D) was established 1957-1958. Replacement housing (symbol C, established 1953-57) took the place of 

wartime and early postwar housing (See Figure 6-1), of which the closest to DP Site would have been the trailer 

park south of DP Road. Map is based on the LAHDRA Project Reference Map produced by cARTography by Andrea Kron. 

Data source: LANL GISLab. 
15-18 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 

Figure 15-7: Aerial view of Los Alamos (circa 1947, looking west) shows DP East (lower center), DP West above it, 

and Los Alamos townsite in the background. Residential area shown include Western Area at the upper left, Eastern 

Area in the upper center, and the area west of (above) the airport that became the site of Group 18 housing at the upper 

right. Photo courtesy Los Alamos Historical Society (LAHM-P1990-40-1-3114). 

DP East 

DP West 

Western Area 

TA-1 

Site of 

Group 18 

housing 

after 1956 

Eastern 

Area 

DP Canyon

Los Alamos

Canyon 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 15-19 

Figure 15-8: This 1949 photo shows a mobile home park located south of DP Road close to Trinity Drive. Located 

directly above the Omega Site reactor buildings in Los Alamos Canyon (upper left corner), the park included both 

private mobile homes and Wingfoot trailers supplied by the government. This area eventually became known as 

Royal Crest park. By August 30, 1963 all occupants were required to move out; some relocated to the “new” Royal 

Crest trailer park on East Jemez Road (Los Alamos Monitor 8/23/63). West of (above) the park are Zia Company 

warehouses and service buildings that supported TA-1. Photo courtesy Los Alamos Historical Society (LAHM-P1989-13-

1-1917).

Omega Site 

(TA-2) Reactor 

Buildings 

Trailer Park 

DP Road

Trinity Dr.
15-20 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 

e. TA-3, the current main Technical Area. 

In 1953, Los Alamos National Laboratory’s (LANL) main technical facilities moved from TA-1, across 

Los Alamos Canyon, to TA-3. Various buildings at TA-3 have housed plutonium, uranium, machining, 

and accelerator operations over the years. An area of interest for releases from TA-3 is the Western Area, 

which is located 0.5 to 1 mile north of the center of TA-3 (see Figures 15-10 and 15-11). LANL winds 

blow toward the north 8.8% of the time. Other possible housing areas to consider with respect to TA-3 

are Replacement Housing, of which construction began in 1953, and Royal Crest Trailer Park, which 

opened in 1960. The closest Replacement Housing to TA-3, which is approximately 0.5 miles northeast 

of TA-3, lies south of Trinity Drive and east of Diamond Drive. Winds blow in the northeast direction 

7.7% of the time as averaged over a 10 year period. Winds blow toward Royal Crest Trailer Park about 

11.4% of the time. 

Figure 15-9: Location of Omega Site and associated reactor stacks relative to several Los Alamos housing 

areas. The trailer park south of DP Road was established around 1948 and was in use through at least 1963 

but gone by 1979. Royal Crest Trailer Park was established in 1960, and remains in use. Reactors operated 

at Omega Site until 1992. Map is based on the LAHDRA Project Reference Map produced by cARTography by 

Andrea Kron. Data source: LANL GISLab. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 15-21 

Figure 15-10: This aerial photo (circa 1967) looks across TA-3 and Los Alamos Canyon to Western Area and the Jemez 

Mountains. The “H”-shaped LASL Administration Building and surrounding structures are in the foreground, Diamond Drive 

runs through the lower right quadrant of the frame, and part of the CMR Building is visible at the lower left edge. Photo courtesy 

Los Alamos Historical Society (LAHM-P2000-2-1-7144). 

Western Area

CMR Building

Los Alamos Canyon 

Diamond Dr.
15-22 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 

f. LAMPF (now LANSCE) 

LAMPF (Los Alamos Meson Physics Facility), which is now called LANSCE (Los Alamos Neutron 

Science Center), is a large accelerator complex located on Mesita de Los Alamos (Figure 15-12). 

Construction began in 1968 and the facility remains in operation today. The location of the off-site 

maximally exposed (hypothetical) individual in LANL’s annual environmental radiological dose 

assessments has typically been at the East Gate/Philomena’s area on State Road 502 where it enters the 

east side of Los Alamos County (LANL 2001). This is because of the area’s proximity to LANSCE, 

which is reflected in Figure 15-13. Philomena’s restaurant was once located 0.5-mile north-northeast of 

the center of the LANSCE complex. According to the 10 year average wind rose, the LANL winds blow 

in this direction 8.3% of the time. 

Fig. 15-11: Location of Technical Area 3 (lower left, established 1953) to some Los Alamos housing areas. 

Western Area (housing symbol A) was established in 1946, "replacement housing" (symbol C) was constructed 

1953-1957, and Royal Crest Trailer Park opened in 1960. Map is based on the LAHDRA Project Reference Map produced 

by cARTography by Andrea Kron. Data source: LANL GISLab.
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 15-23 

Figure 15-13: Location of LANSCE relative to several public areas near LANL. Map is based on the LAHDRA 

Project Reference Map produced by cARTography by Andrea Kron. Data source: LANL GISLab.

Figure 15-12: Aerial view of LANSCE looking towards the southwest. Photo courtesy of LANL.
15-24 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 

g. High explosives manufacturing areas 

Research, development, and testing of high explosives were conducted in over 25 different Technical 

Areas of LANL since the 1940s. The S-Site was chosen as the high explosive manufacturing area 

example for the purposes of this report because it was the main site of early explosives processing 

facilities. S-Site (Figure 15-14) was developed for the production of high explosives in 1943 and 

continues in operation today. A public area of interest for the S-Site is the Western Area, which is 

located 2.75 miles north northeast of this site (see Figure 15-15). The winds blow from the S-Site and in 

the direction of the Western Area 8.3% of the time. Other areas to consider with regards to the S-Site are 

Wartime Housing, Replacement Housing, and Early Postwar Housing, all which were located 

approximately 3 miles from S-Site and experienced winds in their direction about 8% of the time. 

Figure 15-14: High explosives manufacturing facilities were constructed in areas more distant from residential 

areas than original Technical Area buildings, and wider separation between buildings reflected the more readily 

recognized safety hazards of associated operations. This August 1952 aerial view of TA-16 shows Building 260 in 

the upper right of the image. These buildings for machining high explosives were made of concrete and had special 

walls in the back that were built to blow out in the event of an accident. The image shows forested land above and 

below TA-16. Photo courtesy Los Alamos Historical Society (LAHM-P1990-40-3138). 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 15-25

 

Fig. 15-15: Location of TA-16 (S Site) relative to public areas of Los Alamos. Map is based

on the LAHDRA Project Reference Map produced by cARTography by Andrea Kron. Data source: LANL 

GISLab.
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15

h. High Explosives firing sites 

There have been a number of high explosive firing sites at LANL. R-Site was chosen as the 

example for the purposes of this report. Eight firing sites (A-H) were established at R-Site 

between 1944 and 1948, and operations at R-Site continue today. Royal Crest Trailer Park, 

which is located 2 miles north-northeast of the site, is the closest public area to R-Site and 

is an area of interest (see Figure 15-16). According to the LANL wind data, winds blow from 

R-Site towards the trailer park 8.3% of the time. Since R-Site began operations in 1944, 

earlier housing should also be considered when evaluating R-Site releases. Wartime 

Housing, Early Postwar Housing, and Replacement Housing were all about 2.5 miles to the 

north, north-northeast, and north-northeast, respectively. Winds blow in these directions 

8% to 9% of the time. 

Fig. 15-16: Location of TA-15 (R Site) relative to public areas of Los Alamos. Map is

based on the LAHDRA Project Reference Map produced by cARTography by Andrea Kron. 

Data source: LANL GISLab.
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 15-27 

Figure 15-17: Location of Point Able site that was the location of many RaLa shots between 1944 and 1962. The North 

Community (established in 1948) is at the left of the figure (labeled with housing symbol B) and San Ildefonso Pueblo lands 

are east of the LANL boundary at the lower right. Areas associated with housing symbols A, E, G, and H indicate 

residential areas that were established in 1946, 1958, 1977, and the late 1970s, respectively. Map is based on the LAHDRA 

Project Reference Map produced by cARTography by Andrea Kron. Data source: LANL GISLab. 

i. Bayo Canyon firing site 

 

The Bayo Canyon Site (TA-10) was used between 1944 and 1962 for experiments using conventional 

high explosives, radioactive lanthanum (RaLa), and in some cases depleted or natural uranium. Its 

location is shown in Figure 15-17. A public area of interest for the Bayo Canyon site is the Totavi Camp, 

located 5 miles east-southeast of the site down the Bayo Canyon. Since operations at this site were 

conducted in a canyon that runs approximately east to west, wind tends to blow back and forth down this 

canyon. The Totavi Camp was located east south east of the Bayo Canyon site and wind travels in this 

direction 11.9% of the time. Also of interest due to the canyon winds is the North Community, which is 

located 2.5 miles directly west of the Bayo Canyon site. Winds blow in the direction of the North 

Community 3.5% of the time. 

References 

Ahlquist et al. (1977). Ahlquist, A. J., Alan K Stoker, and Linda K Trocki. Radiological Survey and 

Decontamination of the Former Main Technical Area (TA-1) at Los Alamos, New Mexico. Los Alamos 

Scientific Laboratory report LA-6887-MS. December 31. 

ChemRisk (2006). Personal communications between K. Robinson and A. Kron (1/20/2006), B Goldman 

(1/24/2006), R. McKee (1/26/2006), and G. Kalavaza (1/30/2006) regarding San Ildefonso Pueblo Lands 

– Areas of Occupancy. Repos. No. 4941. 

Coffinberry and Miner (1961). Coffinberry, A. S. and W.N. Miner, eds. The Metal Plutonium. 

University of Chicago Press, Chicago, IL. 

North Community
15-28 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 15 

Hunner, J. (2004). Inventing Los Alamos. The growth of an atomic community. Oklahoma: University 

of Oklahoma Press. 

Kron, Andi (personal communication). October 3, 2005. 

LAMD-155 (1947) “Manhattan District History: Supplement to Book VIII, LA Project Y.” 

Los Alamos Scientific Laboratory report LAMD-155. October 15, 1947. 

LANL (2001). Los Alamos National Laboratory. “Environmental Surveillance at Los Alamos during 

2000.” LANL Report LA-13861-ENV. October. 

LASL (1956). “The Housing Manual for Laboratory Employees and Supervisors.” Los Alamos Scientific 

Laboratory of the University of California. September 1 

Martin, C. (1998). Los Alamos Place Names. New Mexico: Los Alamos Historical Society. 

Martin, C. (2000). Quads, shoeboxes and sunken living rooms. A history of Los Alamos housing. New 

Mexico: Los Alamos Historical Society. 10/15/47 

SWEIS (1998). Site-Wide Environmental Impact Statement Project Office. “Overview of Los Alamos 

National Laboratory – 1997.” Environmental, Safety, and Health Division. Los Alamos National 

Laboratory report LA-UR-97-4765. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT- Chapter 16 16-1

Chapter 16: Partial Chronology of Accidents, Incidents, 

 and Events at LANL 

An important part of the review of historical records concerning Los Alamos operations focused 

on the review of records of the Health Division and other records that include descriptions of 

accidents or incidents that had potential association with off-site releases or health effects. Some 

of the incidents of interest include chemical releases, fires, explosions, radiation exposures to 

workers, and other notable accidents that occurred at Los Alamos. The incidents that are 

potentially relevant to off-site releases or health effects are of particular importance. 

Based on review of reports and items of correspondence assembled by the LAHDRA team, a 

partial chronology of accidents, incidents, and events at Los Alamos was compiled. The 

information presented in Table 16-1 is a partial chronology because the information was 

collected from many sources, and it is likely that not all reports documenting accidents and 

incidents were found. Minor worker contamination incidents were not included. Spills of small 

amounts of low toxicity materials to a solid surface that was easily cleaned up were not 

included. The quantity and type of contamination released is reported when available. 

First, Health Division reports in the database were reviewed for incidents of interest. Next, the 

LAHDRA DocSleuth database was searched for selected keywords (such as health report, 

quarterly, monthly H Division progress reports) to obtain additional documents to review. The 

additional documents identified via that keywords search were reviewed and incidents of interest 

were recorded. Next, the search was expanded to include documents relevant to criticality 

incidents, explosions, and RaLa shots. 

In Table 16-1, the first column lists the stated date of the incident or event, or an estimated 

date based on the date of the source document. 

The second column contains a brief description of the incident or event. Any qualitative 

descriptions or impressions given are those of the original document’s authors, as are any 

release quantities or off-site measurements. The original document text can be viewed if 

questions arise or additional information or context is desired. 

The third column in the table contains a categorization of each event. Each event was categorized 

based on the incident type and the potential for off-site release or possible adverse health 

effects. The categories used were as follows: 
16-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT- Chapter 16

• Accident – An incident not involving radioactive or dangerous material 

• Air Release – An incident that involved the release of air contamination 

• Criticality – An event in which a mass of radioactive material went “critical” 

• Equipment Malfunction – An incident that was the result of equipment failure 

• Explosion – An incident that involved an explosion 

• Fire – An incident that involved fire 

• Liquid Release – An incident that involved the release of liquid contamination 

• RaLa Shot – Explosive test event involving radioactive lanthanum 

• User Error – Event involving a human error 

• Contamination Event – Additional unclassifiable contamination events 

The fourth column contains the LAHDRA Repository Number of the source document. In some 

cases, documents contain so many pages that their image files were broken up into pieces to facilitate 

downloading. In these cases, the Repository Number may be followed by a letter, for example 338f 

for the sixth part of a large document having at least six PDF image files. 

The fifth and final column in Table 16-1 contains the page number at which the description of the 

described incident or event begins. This is the page number in the PDF file, which in many cases differs 

from the page number shown on the original document page, as cover pages and early pages of a printed 

document are often not numbered, or in some cases not all pages from the source document were 

requested by the LAHDRA document analysts or released by LANL. 

Over 30,000 pages in over 500 documents were reviewed in the preparation of the chronology of 

accidents and incidents, with those documents including: 

• Contamination incident reports 

• Incident report investigation files 

• Miscellaneous laboratory incident memorandums 

• Radiation occurrence reports 

• A review of criticality accidents 

• A survey of liquid waste management problems at LASL 

• Monthly and annual reports of DP West Site operations 

• Annual reports of the Health Division 

• Health physics/radiation protection quarterly reports 

• Incidents and accidents involving explosives at Los Alamos National Laboratory 

• Reports of the Bayo Canyon/Radioactive Lanthanum (RaLa) Program 

• Airborne Contamination Annual Summaries 

• Summaries of LASL Health Hazards 
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 1 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

9/21/1944 RaLa shot # 1 took place on 9/21/1944 at ~1610 hours. The shot involved ~25 to 60 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all10/4/1944 RaLa shot # 2 took place on 10/4/1944 at 1937 hours. The shot involved 120 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all

10/14/1944 RaLa shot # 3 took place on 10/14/1944 at 1651 hours. The shot involved 60 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all10/26/1944 RaLa shot # 4 took place on 10/26/1944 at 1540 hours. The shot involved 185 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all

11/3/1944

RaLa shot # 5 took place on 11/3/1944 at ~1645 hours. The shot involved 113 Ci of RaLa with an explosive charge of 201 to 350 lbs. An air sampler 

was set up at the edge of Los Alamos Mesa at dwelling T-846, near the present corner of Rim and Canyon Roads, which was the nearest habitation to the firing point. The purpose was apparently to detect any radioactivity that might be carried to the Los Alamos town site, although whether or not Los Alamos was downwind was not recorded. The air samplers were run during each shot and for some time after the shot was fired. The results of each sample were negative, indicating that no radioactivity from these shots reached the town site. 

RaLa Shot 2 all

12/1/1944 RaLa shot # 6 took place on 12/1/1944 at 1630 hours. The shot involved 280 Ci of RaLa with an explosive charge of 201 to 350 lbs. An air sampler was set up at the edge of Los Alamos Mesa as described for shot 5 on 11/3/1944. The results of each sample were negative. RaLa Shot 2 all

12/10/1944 RaLa shot # 7 took place on 12/10/1944 at 635 hours. The shot involved 90 Ci of RaLa with an explosive charge of 201 to 350 lbs. An air sampler was set up at the edge of Los Alamos Mesa as described for shot 5 on 11/3/1944. The results of each sample were negative. RaLa Shot 2 all

12/14/1944 RaLa shot # 8 took place on 12/14/1944 at 2158 hours. The shot involved 110 Ci of RaLa with an explosive charge of 201 to 350 lbs. An air sampler was set up at the edge of Los Alamos Mesa as described for shot 5 on 11/3/1944. The results of each sample were negative. RaLa Shot 2 all

12/20/1944 RaLa shot # 9 took place on 12/20/1944 at 1445 hours. The shot involved 82 Ci of RaLa with an explosive charge of 201 to 350 lbs. An air sampler was set up at the edge of Los Alamos Mesa as described for shot 5 on 11/3/1944. The results of each sample were negative. RaLa Shot 2 all

12/28/1944 RaLa shot # 10 took place on 12/28/1944 at 1535 hours. The shot involved 47 Ci of RaLa with an explosive charge of 20 to 100 lbs. An air sampler was set up at the edge of Los Alamos Mesa as described for shot 5 on 11/3/1944. The results of each sample were negative. RaLa Shot 2 all

2/7/1945 RaLa shot # 11 took place on 2/7/1945 at 1310 hours. The shot involved 220 Ci of RaLa with an explosive charge of 201 to 350 lbs. An air sampler was set up at the edge of Los Alamos Mesa as described for shot 5 on 11/3/1944. The results of each sample were negative. RaLa Shot 2 all

2/11/1945

On February 11, 1945 there was a criticality incident involving UH3 pressed in styrex. The assembly went prompt critical during the dropping of a 

slug of the active material through a vertical hole. The UH3-styrex cubes were swollen and blistered from the heat of the reaction. ~6 x 1015 total 

fissions were involved.

Criticality 6206 all

2/13/1945 RaLa shot # 12 took place on 2/13/1945 at 1945 hours. The shot involved 240 Ci of RaLa with an explosive charge of 201 to 350 lbs. An air sampler was set up at the edge of Los Alamos Mesa as described for shot 5 on 11/3/1944. The results of each sample were negative. RaLa Shot 2 all2/18/1945 RaLa shot # 13 took place on 2/18/1945 at 1626 hours. The shot involved 240 Ci of RaLa with an explosive charge of 601 to 750 lbs. An air sampler was set up at the edge of Los Alamos Mesa as described for shot 5 on 11/3/1944. The results of each sample were negative. RaLa Shot 2 all

2/24/1945 RaLa shot # 14 took place on 2/24/1945 at 1644 hours. The shot involved 135 Ci of RaLa with an explosive charge of 601 to 750 lbs. An air sampler was set up at the edge of Los Alamos Mesa as described for shot 5 on 11/3/1944. The results of each sample were negative. RaLa Shot 2 all

3/3/1945 RaLa shot # 15 took place on 3/3/1945 at 2226 hours. The shot involved 70 Ci of RaLa with an explosive charge of 601 to 750 lbs. An air sampler was set up at the edge of Los Alamos Mesa as described for shot 5 on 11/3/1944. The results of each sample were negative. RaLa Shot 2 all4/1/1945

RaLa shot # 16 took place on 4/1/1945 at 1645 hours. The shot involved 290 Ci of RaLa with an explosive charge of 601 to 750 lbs. An air sampler was set up at the edge of Los Alamos Mesa as described for shot 5 on 11/3/1944. The results of each sample were negative. The date for one of the air samples was recorded as March 31, 1945; however, no shot was fired on that date. Since shot #16 was fired on April 1,1945, the March 31,1945, date is believed to be in error. 

RaLa Shot 2 all

4/9/1945 RaLa shot # 17 took place on 4/9/1945 at 120 hours. The shot involved 530 Ci of RaLa with an explosive charge of 201 to 350 lbs. The cloud tracked toward the ESE. An air sampler was run on Los Alamos Mesa (location unknown) during the shot and for 8 hours afterward. No activity was found. RaLa Shot 2 all

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-3
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 2 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

4/15/1945

RaLa shot # 18 took place on 4/15/1945 at 2035 hours. The shot involved 215 Ci of RaLa with an explosive charge of 201 to 350 lbs. The cloud 

tracked toward the ESE. An air sampler was run at Technical Area 1 (TA-1, the main technical area) for 24 hours to check for contamination. A reading of 50 counts per minute (cpm) gamma radiation was found. “This was the first time that any airborne contamination [associated with Bayo Canyon] was picked up on the mesa.” 

RaLa Shot 2 all

4/20/1945 RaLa shot # 19 took place on 4/20/1945 at 1841 hours. The shot involved 220 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all4/26/1945 RaLa shot # 20 took place on 4/26/1945 at 2143 hours. The shot involved 150 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all

5/11/1945 On May 11, 1945 an accident occurred in Room B2 of Gamma Building. A rotating shield struck a piece of Po metal, sending contamination through out the lab. Contam. Event 3496 8

5/22/1945 RaLa shot # 21 took place on 5/22/1945 at 1547 hours. The shot involved 620 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all5/26/1945 RaLa shot # 22 took place on 5/26/1945 at 1700 hours. The shot involved 450 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all5/30/1945 RaLa shot # 23 took place on 5/30/1945 at 1500 hours. The shot involved 342 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all

6/4/1945 RaLa shot # 24 took place on 6/4/1945 at 1630 hours. The shot involved 900 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all

6/6/1945 On June 6, 1945 there was a criticality incident involving 35.4 kg U-235 in 1/2-inch cubes. The pseudo sphere went critical during water seeping 

between the blocks. ~3x 1016 total fissions were involved. Criticality 6206 all

6/8/1945 RaLa shot # 25 took place on 6/8/1945 at 1545 hours. The shot involved 795 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

6/13/1945 RaLa shot # 26 took place on 6/13/1945 at 1535 hours. The shot involved 569 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all6/16/1945

RaLa shot # 27 took place on 6/16/1945 at 1508 hours. The shot involved 367 Ci of RaLa with an explosive charge of 201 to 350 lbs. A high-capacity 

air sampler was run at the edge of Los Alamos Mesa in front of civilian dwelling T-843 (probably T-846). Thirteen thousand five hundred (13,500) liters of air were sampled, and the beta plus gamma activity on the filter was less than 10 cpm (background). Another sampler was set up at TA-1 in front of Q Building. Results were also negative 

RaLa Shot 2 all

6/22/1945 RaLa shot # 28 took place on 6/22/1945 at 1530 hours. The shot involved 1060 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all6/26/1945 RaLa shot # 29 took place on 6/26/1945 at 1724 hours. The shot involved 737 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all6/29/1945 RaLa shot # 30 took place on 6/29/1945 at 1700 hours. The shot involved 393 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

7/6/1945 RaLa shot # 31 took place on 7/6/1945 at 1718 hours. The shot involved 343 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

7/14/1945 RaLa shot # 32 took place on 7/14/1945 at 1715 hours. The shot involved 190 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all7/16/1945 The world's first nuclear explosion took place at the Trinity site in southern New Mexico at 5:29 a.m. various

8/3/1945 RaLa shot # 33 took place on 8/3/1945 at 2145 hours. The shot involved 471 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all8/6/1945 Little Boy gun type atomic bomb dropped on Hiroshima, Japan.8/9/1945 Fat Man implosion type atomic bomb dropped on Nagasaki, Japan.

8/10/1945 RaLa shot # 34 took place on 8/10/1945 at 1531 hours. The shot involved 240 Ci of RaLa with an explosive charge of 101 to 200 lbs. RaLa Shot 2 all8/15/1945 RaLa shot # 35 took place on 8/15/1945 at 1530 hours. The shot involved 168 Ci of RaLa with an explosive charge of 101 to 200 lbs. RaLa Shot 2 all

8/21/1945

On August 21, 1945 there was a criticality incident involving 6.2 kg gamma-phase Pu. An experimenter was hand stacking tungsten carbide blocks around a Pu mass. The experimenter accidentally dropped a block allowing the Pu to go critical. 1 death and 1 injury resulted from the accident. ~1016 total fissions were involved.

Criticality 6206 all

8/24/1945 RaLa shot # 36 took place on 8/24/1945 at 1556 hours. The shot involved 1200 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

9/1/1945 RaLa shot # 37 took place on 9/1/1945 at 1620 hours. The shot involved 1050 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all9/8/1945 RaLa shot # 38 took place on 9/8/1945 at 1740 hours. The shot involved 628 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-4
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 3 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

9/13/1945 RaLa shot # 39 took place on 9/13/1945 at 1615 hours. The shot involved 440 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all9/20/1945 RaLa shot # 40 took place on 9/20/1945 at 1415 hours. The shot involved 380 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all9/25/1945 RaLa shot # 41 took place on 9/25/1945 at 1740 hours. The shot involved 1291 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

9/26/1945 There was a fire in the contaminated pit September 26, 1945. Contamination was found on the fence surrounding the area and on the guard tower next to the dump. Fire 4525 3-5

10/1/1945 RaLa shot # 42 took place on 10/1/1945 at 1716 hours. The shot involved 772 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all10/6/1945 RaLa shot # 43 took place on 10/6/1945 at 1605 hours. The shot involved 446 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all

10/12/1945 RaLa shot # 44 took place on 10/12/1945 at 1620 hours. The shot involved 516 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all

11/28/1945 On November 28, 1945 in Room 76 of DP Site a worker noticed that a container of Po had leaked. The room was decontaminated. Liquid Release 4525 2

12/14/1945 RaLa shot # 45 took place on 12/14/1945 at 1655 hours. The shot involved 345 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all12/28/1945 RaLa shot # 46 took place on 12/28/1945 at 1620 hours. The shot involved 1340 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

1/4/1946 RaLa shot # 47 took place on 1/4/1946 at 1628 hours. The shot involved 954 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

1/11/1946 RaLa shot # 48 took place on 1/11/1946 at 1600 hours. The shot involved 647 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all1/17/1946 RaLa shot # 49 took place on 1/17/1946 at 1530 hours. The shot involved 459 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all1/24/1946

RaLa shot # 50 took place on 1/24/1946 at 1610 hours. The shot involved 1712 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud 

tracked toward the W. The maximum radiation measured at distance (mR/h) was 0.046 mR/h at 2 miles. The cloud from the shot drifted toward TA-1. Gamma radiation measurements throughout the technical area ranged from 0.028 to 0.046 mR/h. Normal background is about 0.028 mR/h 

RaLa Shot 2 all

1/31/1946 RaLa shot # 51 took place on 1/31/1946 at 1555 hours. The shot involved 1057 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all

2/7/1946 RaLa shot # 52 took place on 2/7/1946 at 1537 hours. The shot involved 654 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

2/14/1946 RaLa shot # 53 took place on 2/14/1946 at 1602 hours. The shot involved 454 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all3/21/1946 RaLa shot # 54 took place on 3/21/1946 at 1520 hours. The shot involved 1034 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all3/28/1946 RaLa shot # 55 took place on 3/28/1946 at 1447 hours. The shot involved 848 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all4/12/1946 RaLa shot # 56 took place on 4/12/1946 at 1555 hours. The shot involved 315 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all

4/15/1946 There was a tuballoy fire in the Tech area on April 15, 1946. Firemen were exposed directly to tuballoy smoke without protective equipment. Fire 4285 11

4/25/1946 RaLa shot # 57 took place on 4/25/1946 at 1520 hours. The shot involved 1324 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

5/2/1946 RaLa shot # 58 took place on 5/2/1946 at 1500 hours. The shot involved 890 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

5/3/1946 There was a explosion in a drybox in Room 107 of D Building on May 3, 1946. The room and adjoining hallway were contaminated. Explosion 4526 2

5/9/1946 RaLa shot # 59 took place on 5/9/1946 at 1440 hours. The shot involved 600 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all

5/16/1946 RaLa shot # 60 took place on 5/16/1946 at 1535 hours. The shot involved 279 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all

5/21/1946

On May 21, 1946 there was a criticality incident involving 6.2 kg of delta-phase Pu. An experimenter was holding two hemispheres of Pu apart with a screw driver as a demonstration to a group. When the screw driver slipped, it allowed the spheres to come together to form a critical mass. 1 death and 7 injuries resulted from the accident. ~3X1015 total fissions were involved.

Criticality 6206 all

5/23/1946 RaLa shot # 61 took place on 5/23/1946 at 1440 hours. The shot involved 1274 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all5/29/1946 RaLa shot # 62 took place on 5/29/1946 at 1450 hours. The shot involved 931 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

6/6/1946 RaLa shot # 63 took place on 6/6/1946 at 1445 hours. The shot involved 539 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

6/27/1946 RaLa shot # 64 took place on 6/27/1946 at 1440 hours. The shot involved 1494 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-5
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 4 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

7/3/1946 RaLa shot # 65 took place on 7/3/1946 at 1625 hours. The shot involved 976 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

7/11/1946 Pu metal turnings caught fire in a drybox in Room 317 on July 11, 1946. The room was highly contaminated. Fire 4526 4

7/11/1946 RaLa shot # 66 took place on 7/11/1946 at 1423 hours. The shot involved 702 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all7/18/1946 RaLa shot # 67 took place on 7/18/1946 at 1530 hours. The shot involved 516 Ci of RaLa with an explosive charge of 201 to 350 lbs. RaLa Shot 2 all

8/1/1946 The first fatality involving energetic materials at Los Alamos was at the Omega-West Reactor Site in August 1946. Thre employees mixed potassium chlorate, sugar, magnesium turnings, and red phosphorous. One person died when the mixture ignited, and two others were injured. Explosion 6203 9

8/28/1946 RaLa shot # 68 took place on 8/28/1946 at 2245 hours. The shot involved 1026 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

11/15/1946 There was a fire in the contaminated dump on November 15, 1946. Fire 4526 1

12/19/1946 RaLa shot # 69 took place on 12/19/1946 at 1640 hours. The shot involved 1261 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all12/27/1946 RaLa shot # 70 took place on 12/27/1946 at 2202 hours. The shot involved 610 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

1/3/1947 RaLa shot # 71 took place on 1/3/1947 at 1920 hours. The shot involved 467 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

1/16/1947 On January 16, 1947 a worker cutting Pu(NO3)4 spilled approximately 70 mg of solution on their pants and the floor of D-146. User Error 3482 2

1/23/1947 On January 23, 1947 a worker with a sledge hammer hit a 5 gallon bottle containing plutonium residue releasing approximately 30 mg of Pu in the basement of D Building. The ground was dug up and buried in the waste disposal pit. User Error 3482 4

3/10/1947 RaLa shot # 72 took place on 3/10/1947 at 2200 hours. The shot involved 570 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all3/14/1947 RaLa shot # 73 took place on 3/14/1947 at 1758 hours. The shot involved 720 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all3/19/1947 RaLa shot # 74 took place on 3/19/1947 at 1952 hours. The shot involved 630 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all4/11/1947 RaLa shot # 75 took place on 4/11/1947 at 140 hours. The shot involved 480 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all4/16/1947 RaLa shot # 76 took place on 4/16/1947 at 1832 hours. The shot involved 640 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

5/6/1947 RaLa shot # 77 took place on 5/6/1947 at 1540 hours. The shot involved 1341 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

5/13/1947 RaLa shot # 78 took place on 5/13/1947 at 1655 hours. The shot involved 1141 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all5/21/1947 RaLa shot # 79 took place on 5/21/1947 at 1926 hours. The shot involved 574 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all6/18/1947 RaLa shot # 80 took place on 6/18/1947 at 1438 hours. The shot involved 170 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all6/25/1947 RaLa shot # 81 took place on 6/25/1947 at 1319 hours. The shot involved 1290 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

7/2/1947 RaLa shot # 82 took place on 7/2/1947 at 1800 hours. The shot involved 1320 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

7/10/1947 RaLa shot # 83 took place on 7/10/1947 at 1703 hours. The shot involved 851 Ci of RaLa with an explosive charge of 101 to 200 lbs. RaLa Shot 2 all7/30/1947 RaLa shot # 84 took place on 7/30/1947 at 1850 hours. The shot involved 1070 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

8/6/1947 RaLa shot # 85 took place on 8/6/1947 at 1706 hours. The shot involved 700 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

8/13/1947 RaLa shot # 86 took place on 8/13/1947 at 1545 hours. The shot involved 680 Ci of RaLa with an explosive charge of 101 to 200 lbs. RaLa Shot 2 all8/27/1947 RaLa shot # 87 took place on 8/27/1947 at 2022 hours. The shot involved 1610 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

9/4/1947 RaLa shot # 88 took place on 9/4/1947 at 1655 hours. The shot involved 925 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

9/11/1947 RaLa shot # 89 took place on 9/11/1947 at 1625 hours. The shot involved 670 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all9/18/1947 RaLa shot # 90 took place on 9/18/1947 at 1420 hours. The shot involved 438 Ci of RaLa with an explosive charge of 101 to 200 lbs. RaLa Shot 2 all

10/22/1947 A fire was detected on October 22, 1947 in the contaminated dump. The results of monitoring during and after the fire reportedly indicated that there was no significant exposure to radioactive materials. Fire 4285 8

10/29/1947 RaLa shot # 91 took place on 10/29/1947 at 1543 hours. The shot involved 1670 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-6
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 5 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

11/5/1947 RaLa shot # 92 took place on 11/5/1947 at 1522 hours. The shot involved 946 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

11/7/1947 On November 7, 1947 pressurized radioactive spray was released from a line of the peroxider unit contaminating one worker. Equipment Malfunction 3482 11

11/12/1947 RaLa shot # 93 took place on 11/12/1947 at 1543 hours. The shot involved 730 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all11/27/1947 RaLa shot # 94 took place on 11/27/1947 at 1755 hours. The shot involved 720 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

12/3/1947 RaLa shot # 95 took place on 12/3/1947 at 1735 hours. The shot involved 1056 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

12/10/1947 RaLa shot # 96 took place on 12/10/1947 at 1816 hours. The shot involved 706 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all12/18/1947 RaLa shot # 97 took place on 12/18/1947 at 1529 hours. The shot involved 619 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

1/29/1948 RaLa shot # 98 took place on 1/29/1948 at 1436 hours. The shot involved 1240 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

2/5/1948 RaLa shot # 99 took place on 2/5/1948 at 1906 hours. The shot involved 1010 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

2/19/1948 RaLa shot # 100 took place on 2/19/1948 at 1459 hours. The shot involved 590 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all2/27/1948 RaLa shot # 101 took place on 2/27/1948 at 1440 hours. The shot involved 310 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

4/1/1948 RaLa shot # 102 took place on 4/1/1948 at 1630 hours. The shot involved 980 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all4/9/1948 RaLa shot # 103 took place on 4/9/1948 at 1517 hours. The shot involved 620 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

4/16/1948 RaLa shot # 104 took place on 4/16/1948 at 1455 hours. The shot involved 400 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

6/16/1948 On June 16, 1948 there was a fire in the drybox of Room D-115. The fire was believed to have been caused by spontaneous combustion of U-235 lathe turnings. Fire 1184 65

8/4/1948 RaLa shot # 105 took place on 8/4/1948 at 1626 hours. The shot involved 590 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

8/12/1948

RaLa shot # 106 took place on 8/12/1948 at 1540 hours. The shot involved 771 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud 

tracked toward the SW. No activity above background was measured in the vicinity of the airstrip (now Los Alamos Airport). The roads north and south of the airstrip were checked. A film badge planted at the east end of the airstrip had only 0.003 R exposure, which is close to the limit of sensitivity for this device. 

RaLa Shot 2 all

8/19/1948 RaLa shot # 107 took place on 8/19/1948 at 1625 hours. The shot involved 547 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all9/10/1948 RaLa shot # 108 took place on 9/10/1948 at 1721 hours. The shot involved 1735 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

9/14/1948 On September 14, 1948 workers cleaned out a drybox in Room 126. The material was taken to the hood in Room 119 where it was accidentally released. The room was decontaminated the following day. User Error 3485 7

9/21/1948 RaLa shot # 109 took place on 9/21/1948 at 1543 hours. The shot involved 1006 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all9/28/1948 RaLa shot # 110 took place on 9/28/1948 at 1538 hours. The shot involved 487 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all10/7/1948 RaLa shot # 111 took place on 10/7/1948 at 1410 hours. The shot involved 362 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

10/14/1948 RaLa shot # 112 took place on 10/14/1948 at 1442 hours. The shot involved 205 Ci of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all10/21/1948 RaLa shot # 113 took place on 10/21/1948 at 1411 hours. The shot involved 123 Ci of RaLa with an explosive charge of 20 to 100 lbs. RaLa Shot 2 all

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-7
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 6 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

12/1/1948

RaLa shot # 114 took place at 1608 hours. The shot involved 480 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward the 

south. H-1 leader T. N. White observed the cloud to drift a few points west of south and most of it appeared to settle down into Pueblo Canyon, just north of main hill road. White also saw a wisp go over Emilio Segre's old laboratory (East Gate Laboratory) at the extreme eastern end of Los Alamos Mesa. White went there with a radiation survey meter and was able to locate activity at the tip of the mesa. A few specks gave a reading that was close to the maximum with the beta shield open (20 mR/h). There was no activity a hundred feet or more to the west of the mesa tip. Following this observation, White expressed concern to D. Mueller, the leader of the Bayo Canyon experimenters, that it was undesirable to set off shots without regard to wind direction and velocity.

RaLa Shot 2 all

12/8/1948 RaLa shot # 115 took place on 12/8/1948 at 2039 hours. The shot involved 463 Curies of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

12/15/1948 RaLa shot # 116 took place on 12/15/1948 at 1345 hours. The shot involved 317 Curies of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward the E. The wind speed was 10 mph. The maximum radiation measured at distance was 0.76 mR/h at 0.25 miles. RaLa Shot 2 all

1/25/1949 RaLa shot # 117 took place on 1/25/1949 at 405 hours. The shot involved 452 Curies of RaLa with an explosive charge of 351 to 600 lbs. RaLa Shot 2 all

2/1/1949 RaLa shot # 118 took place on 2/1/1949 at 1630 hours. The shot involved 487 Curies of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all3/4/1949 RaLa shot # 119 took place on 3/4/1949 at 1359 hours. The shot involved 693 Curies of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all3/8/1949 RaLa shot # 120 took place on 3/8/1949 at 1413 hours. The shot involved 604 Curies of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

3/31/1949 RaLa shot # 121 took place on 3/31/1949 at 1647 hours. The shot involved 1096 Curies of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all4/20/1949

RaLa shot # 122 took place on 4/20/1949 at 1846 hours. The shot involved 422 Curies of RaLa with an explosive charge of 601 to 750 lbs. A monthly 

progress report of the Health Division stated, “The radioactive cloud from the Bayo shot of April 20 passed over and contaminated the area of the main gate to Los Alamos. The Fire Department washed off the most heavily contaminated section of the road shortly thereafter.” No survey report has been found. 

RaLa Shot 2 all

4/27/1949 RaLa shot # 123 took place on 4/27/1949 at 2045 hours. The shot involved 1244 Curies of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

5/4/1949 RaLa shot # 124 took place on 5/4/1949 at 2045 hours. The shot involved 1740 Curies of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all

5/11/1949 RaLa shot # 125 took place on 5/11/1949 at 1950 hours. The shot involved 1393 Curies of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all5/17/1949

RaLa shot # 126 took place on 5/17/1949 at 2030 hours. The shot involved 871 Curies of RaLa with an explosive charge of 601 to 750 lbs. A day after 

the last Bayo Canyon shot (#126) “activity was discovered at a point about two miles north of the Bayo firing site. The general background activity [meaning contamination] in this area was of the order of 1 mr/hr beta plus gamma ...” (presumed to be at waist height). 

RaLa Shot 2 all

5/20/1949

RaLa shot # 127 took place at 1830 hours. The shot involved 588 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward the 

ESE. The wind speed was 10 mph. The cloud from the shot crossed State Road 4 between Station 101 (a temporary guard gate at the access road to Bayo Canyon) and the McKee Trailer Camp on State Road 4. Roadblocks were established at the Main Gate and lower Bayo Canyon road junction with the main hill road. Following the shot, the blocked-off section of the road and a section running about 1 mi. east were monitored and found to be free of contamination; the roadblocks were removed. Shortly thereafter a second monitoring patrol discovered contamination on the road to the east of Frijoles Junction (the White Rock Y at the intersection of main hill road and State Road 4), which had been thought to be clean. Roadblocks were reestablished at the Main Gate. The most heavily contaminated stretch of road ran about 0.75 miles east of Frijoles Junction. The highest readings were 5 to 10 mR/h 12 inches from the ground. 

RaLa Shot 2 all

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-8
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 7 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

6/2/1949

RaLa shot # 128 took place at 1417 hours. The shot involved 1933 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward 

the north. The wind speed was 12 mph. The maximum radiation measured at distance was 1.5 mR/h at 1.5 miles. “Flypaper and pans [adhesive fallout collectors] distributed in Guaje Canyon previous to the shot were collected approximately two hours afterwards and were found to have no contamination. The following afternoon, however, approximately 15 mr/hr beta and gamma background [assumed at 12 inches] was found in the region over which the cloud passed.” Because “the meteorologist estimated that the cloud reached this position about five minutes after the shot,” the conclusion can be reached that the flypaper and pans were not located in the main path of the fallout. 

RaLa Shot 2 all

6/6/1949

RaLa shot # 129 took place at 2206 hours. The shot involved 1630 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward 

the SE. The maximum radiation measured at distance was 1.5 mR/h at 2.5 miles. Adverse weather continued until after the shot. “An attempt was made by Health Division personnel to postpone the shot until such time that conditions were more favorable, but the decision was made to continue.” After the shot it became apparent that a portion of the main road to Los Alamos (SR 502) would become contaminated. Road blocks were placed at the west end of the airstrip, the junction of SR 4 and Sandia Canyon, and above Totavi Camp. Monitoring on the main road showed contamination from the 

pump house at the Bayo Canyon turnoff to 0.5 miles above Totavi, a distance of about 1.5 miles. The highest reading obtained was about 15 mR/h beta plus gamma at the main hill road and SR 4 junction. This measurement was taken at 12 inches above the road surface rather than at the usual 3 feet as was adopted later. 

RaLa Shot 2 all

6/10/1949

RaLa shot # 130 took place on 6/10/1949 at 933 hours. The shot involved 1280 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud 

tracked toward the NW. The wind speed was 6 mph. “Considerable effort was made by all persons involved to plan this particular operation so that the difficulties encountered in previous operations would not be present.” Continuous weather predictions were done until after the shot. “The cloud drifted off in a northwesterly direction.... Although the main portion of the cloud did not pass over any of the previously placed trays and flypaper in Guaje Canyon, a small amount of background was found seven hours later on two of them located at one edge of the cloud path.” 

RaLa Shot 2 all

7/28/1949 RaLa shot # 131 took place on 7/28/1949 at 1204 hours. The shot involved 1387 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward the N, NE. RaLa Shot 2 all

8/3/1949 RaLa shot # 132 took place on 8/3/1949 at 1258 hours. The shot involved 936 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward the N, NE. RaLa Shot 2 all8/9/1949 RaLa shot # 133 took place on 8/9/1949 at 957 hours. The shot involved 713 Curies of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward the N, NE. RaLa Shot 2 all

8/18/1949 On June 27, 1949 there was a fire outside of TU Buildings. Fire resulted from the spontaneous combustion of TU shavings stored outside TU Building. Surrounding area was highly contaminated. Fire 1184 169

8/31/1949 RaLa shot # 134 took place on 8/31/1949 at 1200 hours. The shot involved 715 Curies of RaLa with an explosive charge of 601 to 750 lbs. RaLa Shot 2 all9/14/1949

Rala shot # 135 took place on 9/14/1949 at 1202 hours. The shot involved 356 Curies of RaLa with an explosive charge of 601 to 750 lbs. Flypapers 

placed on North Ridge (the closest northern approach to Bayo Canyon, about 0.5 miles north, a little west, and 400 feet above of the firing site) about 50 paces apart read 3 to 4 mR/h at 1 inch with a closed-shield GM survey meter. 

RaLa Shot 2 all

9/23/1949

RaLa shot # 136 took place on 9/23/1949 at 1018 hours. The shot involved 346 Curies of RaLa with an explosive charge of 601 to 750 lbs. The cloud 

tracked toward the SE. The wind speed was 8 mph. Nine flypapers placed on North Ridge read 0.15 to 1.0 mR/h at I inch with a closed-shield GM survey meter; the maximum reading was recorded 300 paces from the eastern-most station; the pattern appears to be skewed to the west. 

RaLa Shot 2 all

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-9
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 8 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

10/19/1949

RaLa shot # 137 took place on 10/19/1949 at 1007 hours. The shot involved 1385 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud 

tracked toward the N, NE. The wind speed was 15-20 mph. Flypapers placed on North Ridge read from 0.1 to 0.3 mR/h at 1 inch, measured with a closed-shield GM survey meter. The maximum flypaper reading was recorded 150 paces west of the eastern edge of the array. The ground measured 0.07 mR/h near and in good agreement with one of the flypapers, which read 0.1 mR/h. The dose rate recorder at the same location reached 1.5 mR/h as the cloud passed. A survey made the next day in Rendija Canyon about a mile east of the Sportsman's Club showed a maximum of 0.07 mR/h. 

RaLa Shot 2 all

11/2/1949

RaLa shot # 138 took place at 1205 hours. The shot involved 1614 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward 

the W. The maximum radiation measured at distance was 0.8 mR/h at 2.5 miles. T. Shipman reported “an abrupt and temporary shift in the wind ... resulted in blowing the cloud ... across the Technical Area [TA-1]. As far as health and safety are concerned, no significant levels of radiation have been found. There is, however, sufficient contamination so that the background in certain counting procedures may be disturbed.” “Demonstrable contamination was found as far away as Camp May, a distance often miles' [west], but at no place were levels of contamination found to be very high.” Levels of radiation were three times background at the Base Radio Station on North Mesa. The tip of Center Mesa read 0.6 mR/h; the Chapel Apartment area on Rose Street read 0.8 mR/h; Manhattan Loop read 0.3 to 0.4 mR/h; the peak at the main gate was 1.0 mR/h gamma (1.5 mR/h, beta plus gamma). Measurements made on North Ridge were all background. 

RaLa Shot 2 all

11/8/1949

RaLa shot # 139 took place on 11/8/1949 at 1243 hours. The shot involved 1064 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud 

tracked toward the NE. The wind speed was 7-9 mph. The cloud moved west up canyon and then northeast, missing the North Ridge flypaper array. No record of radiation measurements in surrounding areas was found. 

RaLa Shot 2 all

11/14/1949 On November 14, 1949 an accident occurred between two security trucks. One truck was carrying wooden crates of steel cylinders that contained plutonium. Only one wooden crate was damaged and no contamination occurred. Accident 3484 7

12/1/1949 In December, 1949 there was a criticality incident involving ~1 kg 235U UO2 (NO3)2 in 13.6 liters water during the manual withdrawal of two poison 

control rods. 3.4x1016 total fissions were involved. Criticality 6206 all

12/8/1949

RaLa shot # 140 took place on at 1532 hours. The shot involved 2635 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked 

toward the NE. The wind speed was 8-12 mph. The maximum radiation measured at distance was 0.6 mR/h at 2 miles. Readings from the North Ridge flypapers ranged from background to 2.5 mR/h at 1 inch measured with a closed-shield GM survey meter. The maximum reading was found on the station 50 paces from the eastern end of the nine-station array. The Point Pluto (labeled 23) recorder showed cloud passage and the collected air sample was “3X normal = 0.015 mr/ hr.” At Point Claim, the cloud passed, and a sample read “0.6 mr/hr gammas only.” Guaje Canyon was monitored the next day and a maximum of 0.2 mR/h was found "opposite Pt. Claim." Also recorded are some "GMX-5 data giving 1.2 mr/hr in Rendija Canyon N of 12 and 0.5 mr/hr N of 10." 

RaLa Shot 2 all

12/16/1949

RaLa shot # 141 took place at 1739 hours. The shot involved 1539 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward 

the NW. The wind speed was 2-3 mph. The maximum reading on flypaper on North Ridge read 1 mR/h at 1 inch, measured with a closed-shield GM survey meter. The cascade impactor at Point Claim showed most of the activity to be collected on the final (filter) stage, 0.7-micron particles if density 2.5 is assumed. Another handwritten description of the December 16 shot exists and has some valuable contemporary thinking comparing RaLa with radium and some dimensional help. But, again, all discussion was aimed, as were the previous flypaper measurements, at showing whether providing an asphalt pad under the shots would reduce fallout. It apparently did. The writer calculated the effect of the worst-case (wind conditions, RaLa source size) fallout on the Guaje reservoir (a partial source of Los Alamos water at that time) to be 0.1 uCi/L or 1 mR/day for continuous intake. 

RaLa Shot 2 all

12/22/1949

RaLa shot # 142 took place at 1632 hours. The shot involved 1132 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward 

the SW. The wind speed was 3-5 mph. A “mild degree of contamination” was recorded in some parts of TA-1. No health hazard occurred; however, background activity may have been elevated enough to affect some TA-1 laboratory counting procedures. 

RaLa Shot 2 all

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-10
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 9 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

1/13/1950 RaLa shot # 143 took place at 1248 hours. The shot involved 2065 Curies of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward the E, SE. The wind speed was 25 mph. RaLa Shot 2 all

1/17/1950 RaLa shot # 144 took place on 1/17/1950 at 1347 hours. The shot involved 1715 Curies of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward the north and then east. The wind speed was 4-7 mph. RaLa Shot 2 all

1/24/1950 RaLa shot # 145 took place on at 1138 hours. The shot involved 1737 Curies of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward the E, NE. The wind speed was 25-30 mph. The cloud from the shot remained in Bayo Canyon. RaLa Shot 2 all1/31/1950 RaLa shot # 146 took place on 1/31/1950 at 1417 hours. The shot involved 981 Curies of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward the E, NE. The wind speed was 9-17 mph. RaLa Shot 2 all3/24/1950 RaLa shot # 147 took place on 3/24/1950 at 1323 hours. The shot involved 1665 Curies of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward the E. The wind speed was 28-42 mph. A B-17 flight took place. RaLa Shot 2 all3/29/1950

RaLa shot # 148 took place at 1416 hours. The shot involved 1743 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward 

the W, WNW, and NNE. The wind speed was 2-8 mph. The maximum radiation measured at distance was 0.2 mR/h at 3 miles. “... a slight amount of contamination from fall-out was observed throughout the town site and Tech Area [TA-1]” following shot #148. It was obvious that weather conditions would not be ideal at shot time, but there was reluctance to cancel the shot for the day since weather predictions for the remainder of the week were no better. H Division authorized continuation of the operation. “The vast majority of it [the cloud] apparently moved out to the northwest toward the upper portions of Guaje Canyon. A small portion of the cloud ... took a southerly course and left detectable contamination in parts of the Los Alamos housing area (particularly in the Denver steel area), [which was the housing area closest to Bayo Canyon] and also in the Tech Area. The average levels of activity found were in the vicinity of 0.2 mr/h [Beta + gamma]... .There certainly is no reason to feel that the situation produced any health hazard whatsoever.” 

RaLa Shot 2 all

4/6/1950 RaLa shot # 149 took place at 1330 hours. The shot involved 1306 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward the NNW, NNE. The wind speed was 18-37 mph. A B-17 flight took place. RaLa Shot 2 all

4/20/1950 RaLa shot # 150 took place at 1431 hours. The shot involved 3334 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward the N, NW. The wind speed was 4-12 mph. RaLa Shot 2 all

4/26/1950

Rala shot # 151 took place on 4/26/1950 at 1400 hours. The shot involved 2496 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud 

tracked toward the E, SE. The wind speed was 5-30 mph. The Point Myrtle weather observer was directly under the cloud as it passed over but “he experienced no contamination.” 

RaLa Shot 2 all

5/12/1950 Rala shot # 152 took place on 5/12/1950 at 1359 hours. The shot involved 1355 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward the S, SW. The wind speed was 10-15 mph. RaLa Shot 2 all

5/24/1950 Rala shot # 153 took place on 5/24/1950 at 1152 hours. The shot involved 391 Ci of RaLa with an explosive charge of 601 to 750 lbs. The cloud tracked toward the NE. The wind speed was 6-15 mph. RaLa Shot 2 all

5/29/1950 On May 29, 1950 the contaminated waste disposal pit caught fire. Fire 3483 76/27/1950 On June 27, 1950 -250 g of UO3 were spilled during the transfer from a cabinet to the hood. Contam. Event 3483 8

7/13/1950

Rala shot # 154 took place on 7/13/1950 at 1410 DST hours. The shot involved 1000 Ci of RaLa with an explosive charge of 601 to 750 lbs. The 

cloud tracked toward the NE and N. The wind speed was 8-26 mph. The cloud motion observer's report stated “The cloud track given herein applies to only a small segment of the cloud. The bulk of the cloud seemed to dissipate without ever rising above the canyon walls.” 

RaLa Shot 2 all

8/18/1950 On August 18, 1950 a tank containing contaminated ammonium nitrate was found leaking. The floor and area was decontaminated. Liquid Release 3483 810/3/1950 On October 3, 1950 a container of PuO2 was opened and contaminated Room 513 of CMR 12. User Error 3483 13

2/1/1951 On February 1, 1951 at Pajarito Site an experiment went critical during a remote control operation. Criticality 1571 5

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-11
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 10 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

2/1/1951 On February 1, 1951 there was a criticality incident involving 2 cylinders of U-235. The cylinders weighted 24.4 kg and 38.5 kg of 93% U-235. The 

2 cylinders were in a water reflected system. There was slight oxidation of the uranium. 1017 total fissions were involved. Criticality 6206 all

9/13/1951 On September 13, 1951 in Room 201 of DP West a drybox caught fire contaminating the room. Fire 3486 79/29/1951 On September 29, 1951 a bottle containing 10 grams of enriched U-235 was dropped in Room 307 spilling the contents on the floor. Contam. Event 3486 910/6/1951 An accident occurred on October 6, 1951 and high levels of contamination were spread in Building 52 of DP East. Everyone leaving was monitored and two cars were found to be contaminated and they were cleaned before the employees left for home. Air Release 3486 9

10/23/1951

On October 23, 1951 a beaker containing 8 hydroxy quinoline and plutonium exploded releasing contamination into Room D-304. The filter queen located in D-304 was changed immediately and very high levels of contamination were found. The amount of Pu present in the solution was not over 1-2 milligrams.

Explosion 3486 9

3/26/1952

Rala shot # 155 took place on 3/26/1952 at 1652 hours. The shot involved 270 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the SE. The wind speed was 20 mph. The maximum radiation measured at distance was 0.15 mR/h at 1.5 miles. Radiation monitoring started from Point Weather westward and included the northern part of the Los Alamos housing area; 0.04 mR/h was recorded 0.1 miles from Point Weather. No activity above background was detected elsewhere on return to TA-1. A second monitor started from the Main Hill Road intersection with State Road 4 and found no activity except “0.15 mr/h in the vicinity of the first large bend in the road east of the main guard gate.” No activity was detected in TA-1. 

RaLa Shot 2 all

4/18/1952 On April 18, 1952 there was a criticality incident involving 92.4 kg U metal 93% 235U due to computation error 1.5x1016 total fissions were involved. Criticality 6206 all

6/16/1952 On June 16, 1952 plutonium metal ignited in an open port drybox in D-138 of D Building. The fire was quickly quenched with water. Fire 3495 9

8/11/1952

Rala shot # 156 took place on 8/11/1952 at 1755 hours. The shot involved 2400 Ci of RaLa with an explosive charge of 101 to 200 lbs. Monitoring began from Point Weather, where activity of 0.05 mR/h was recorded. At the picnic grounds (on North Mesa), background activity was recorded. At the Sportsman's Club and 35th and Diamond Drive, less than 0.1 mR/ h was recorded. Throughout North Community, activity was less than 0.05 mR/h. The survey sheet noted “... before shot background was 0.15, after shot 0.1 mr.” 

RaLa Shot 2 all

8/21/1952

Rala shot # 157 took place on 8/21/1952 at 1151 hours. The shot involved 2900 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the N. High-volume air samplers located at Station 20 (on Puye Road), White Rock, Well #3 (just east of Guaje pumice mine), and Totavi gave the following results: 239, 689, 460, and 931 cpm, respectively. Five-stage cascade impactor data were as follows: at White Rock, all five stages—0 cpm; at Well #3, 4th stage—31 cpm, 5th stage (Whatman #41 paper)—4 cpm; Totavi, 5th stage (molecular filter)—16 cpm. 

RaLa Shot 2 all

8/29/1952

Rala shot # 158 took place on 8/29/1952 at 1259 hours. The shot involved 800 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the E, NE. Air samplers run in Espanola and on Puye Road showed activity in the 30- to 100-nCi range. “Good coverage was obtained on the last Bayo shot [#158] and evaluation of these data has been completed showing no hazard in any inhabited areas.” 

RaLa Shot 2 all

12/9/1952 On December 9, 1952 in S-104 uranium in a furnace caught fire and was contained in the furnace. Clean-up of S-104 was conducted on December 11 and 12. Fire 3495 11

1/8/1953 On January 8, 1953 a mock fission polonium beryllium source ruptured releasing as much as 2 Ci of Po. Significant amounts of polonium contamination was found in nearby homes. Air Release 124 1

1/8/1953 On January 8, 1953 Po contamination was discovered at Pajarito Site Room 119 of Building 30. Employees of W-2 were exposed over a period of at least a week and several employee homes were contaminated. By January 13, 1953 all of W-2 and W-5 and SD houses were decontaminated. Contam. Event 3492 14/3/1953 On April 3, 1953 the city dump was possibly contaminated with 125 lbs of tuballoy. 26 lbs were recovered, and the remainder was incinerated. The top layer of ashes was removed and three truck loads of dirt were placed over the contamination site. User Error 191 53

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-12
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 11 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

6/10/1953

Rala shot # 159 took place on 6/10/1953 The shot was not fired, the explosive burned. Fallout trays on the main hill road and one high-volume air 

sampler in Guaje Canyon showed measurable activity. The monthly progress report of H-1 (the Health Physics Group) stated, “Although the east project access road [main hill road] was contaminated, the levels were low enough that they did not constitute a health hazard.” 

RaLa Shot 2 all

6/26/1953 On June 26, 1953 there was a small fire in a flask containing uranium hydride in D-151. Fire 3491 46/29/1953 On June 29, 1953 an employee spilled approximately 40 μg of plutonium nitrate in Z Building on the floor. The area was decontaminated the following day. Contam. Event 3491 5

8/10/1953 On August 10, 1953 a dissolver exploded releasing U-235 over the entire room. Explosion 3491 9

8/14/1953 Rala shot # 160 took place on 8/14/1953 at 1402 hours. The shot involved 600 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the SE. The wind speed was 10 mph. RaLa Shot 2 all

9/10/1953 Rala shot # 161 took place on 9/10/1953 at ~1400 hours. The shot involved 250 Ci of RaLa with an explosive charge of 20 to 100 lbs. RaLa Shot 2 all10/9/1953 Rala shot # 162 took place on 10/9/1953 at ~1300 hours. The shot involved 215 Ci of RaLa with an explosive charge of 20 to 100 lbs. RaLa Shot 2 all

11/12/1953 On November 12, 1953 there was an undetermined explosion in Room 501 that contaminated the room. Explosion 3491 12

12/5/1953 On December 5, 1953 a glass furnace in a vacuum hood exploded releasing 40g of uranium. Explosion 3491 131/28/1954 On January 28, 1954 a fire occurred at the contamination dump. Fire 1184 233

2/1/1954

There have been 8 accidental prompt-critical excursions at Pajarito Site to date. The dates of the accidents are February 1951; April 1952, February 1954; July 1956; February 1957; June 1960; December 1962; May 1967. The only notable damage that occurred was in the February 1954 event. During that even there was a slight warping of the U(93) pieces, but no measurable fission-products were released.

Criticality 3167 18

2/1/1954 There was no measurable fission-product release during the worst accidental excursion at Pajarito, the second Lady Godiva accident. Criticality 3168 12/3/1954 On February 3, 1954 there was a criticality incident involving 53 kg U metal 93% 235U due to incorrect operation at the Lady Godiva reactor. There 

was a slight warping of the pieces. 5.6 x 1016 total fissions were involved. Criticality 6206 all

2/8/1954 On February 8, 1954 in CMR- 4 tritium was released when a U-tube cracked under a hood. Air Release 3493 2

2/12/1954

Rala shot # 163 took place on 2/12/1954 at 1620 hours. The shot involved 2730 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the NE. Two air-sampling count data sheets provided the following information: one for Puye [Road], background activity; one for Espanola, 44 net cpm; no conversion to disintegrations per minute are given. 

RaLa Shot 2 all

3/8/1954 Rala shot # 164 took place on 3/8/1954 at 1615 hours. The shot involved 2000 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the E. RaLa Shot 2 all

3/19/1954 Rala shot # 165 took place on 3/19/1954 at 1130 hours. The shot involved 150 Ci of RaLa with an explosive charge of 101 to 200 lbs. RaLa Shot 2 all

3/29/1954 On March 29, 1954 an 800-pound pig slipped and dropped off the tailgate of a pickup dumping a white powder on the truck and the dock. The area became contaminated with Sr-90 and was decontaminated. No one was allowed to wear contaminated clothing home. User Error 3493 13

4/14/1954

Rala shot # 166 took place on 4/14/1954 at 1345 hours. The shot involved 190 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud 

tracked toward the SE. No radiation was detected. Fallout was monitored starting at the main gate. Otowi ruins. White Rock, Mora's Castle (also known as the Duchess' Castle), Otowi Bridge, and 5 miles up Espanola highway (State Road 5) were surveyed from the main hill road. No readings above background were obtained. 

RaLa Shot 2 all

4/19/1954 On April 19, 1954 a mixture containing 5 milligrams of americium exploded. Explosion 3493 14

7/2/1954 Glass tube holding plutonium covered wire broke releasing Pu at Y Building on July 2, 1954. Equipment Malfunction 2364 3

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-13
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 12 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

7/31/1954

RaLa shot # 167 took place at 1605 hours. The shot involved 1400 Ci of RaLa with an explosive charge of 101 to 200 lbs. The maximum radiation 

measured at distance was 1.5 mR/h at 2.25 miles. The cloud started to the NE with very little velocity; the wind shifted shortly after the shot took place and spread fallout to the SE and S. A rain shower occurred in Bayo Canyon 35 minutes after the shot. Activity was detected between SR 4 and the Sandia Canyon guard station, one-half mile east of SR 4. Measurements in White Rock showed background activity. The next evening, 1 mR/h was measured at Otowi ruins. A hand-drawn fallout map was made, from which D. Meyer deduces, “Fallout area was approximately 4 square miles... average reading was 0.5 mr/hr with shield open at waist level. This equals to about 1 mr/hr at contact shield open or 0.15 mr/hr shield closed at 6” from ground.” 

RaLa Shot 2 all

8/5/1954

RaLa shot # 168 took place at 1830 hours. The shot involved 1500 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the NE. The wind speed was 0 mph. The maximum radiation measured at distance was 0.4 mR/h at 2.5 miles; 0.15 mR/h at 12 miles. The team made background readings in Rendija Canyon to the north and northeast several hours before the shot, finding elevated background activity from the previous shot (#167). After the shot, a counterclockwise survey began, reaching Totavi at 1845. The team returned up Guaje Canyon, encountering new fallout measuring 0.4 mR/h at the pumice mine (background in the morning was 0.04 mR/h) but found no further increase over the earlier background activity as far as the junction of Guaje and Rendija canyons. The team returned down Guaje Canyon and proceeded toward Espanola, encountering activity 4.5 miles south of Espanola with a maximum of 0.2 mR/h at the Puye Road turnoff. Activity was 0.15 mR/h at Santa Clara Pueblo and 0.1 to 0.15 mR/h in Espanola. The team returned to Puye Road the next morning and found slightly lower readings than the day before.

RaLa Shot 2 all

9/9/1954

RaLa shot # 169 took place at 1518 hours. The shot involved 265 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the 

S. The wind speed was 1 mph. The maximum radiation measured at distance 0.1 mR/h at 1 mile; 0.45 mR/hr at 2 miles 0.3 mR/hr at 2.5 miles; 0.18 mR/hr at 4 miles. The survey team passed the Los Alamos airstrip at 1538, where fallout was encountered; a maximum of 1.1 mR/h was recorded 1.4 miles east of the airport. Team members completed the survey including west up Guaje Canyon; all readings were background, which varied between 0.03 and 0.05 mR/h. More readings were taken the next day on other roads further south; a fallout map was prepared showing a relatively narrow fallout pattern to the south-southwest over laboratory property, crossing Sandia Canyon, 0.45 mr/hr, and other east-west roads in the laboratory area.

RaLa Shot 2 all

9/16/1954

RaLa shot # 170 took place at 1458 hours. The shot involved 300 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the 

NW. No radiation was detected. The team started a clockwise survey from TA-1 before 1500 and continued on to Espanola and Riverside (east side of Espanola). No fallout above background was detected. A map was made.

RaLa Shot 2 all

10/21/1954 An electrode broke within a flask causing tritium to be released into the hood in Room 220 of HRL Building on October 21, 1954. Equipment Malfunction 2368 3

10/24/1954 U-235 material ignited spontaneously in the sigma vault on October 24, 1954. Fire 2368 3

11/4/1954

RaLa shot # 171 took place at 1335 hours. The shot involved 2200 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the N. The wind speed was 7 mph. The maximum radiation measured at distance was 0.3 mR/h at 1.5 miles. The team started a clockwise perimeter survey from TA-1 at 1600; background activity was 0.03 mR/h. All readings were background to State Road 4. The team returned up Guaje/Rendija Canyons and measured 0.3 mR/h for about 0.5 miles beginning 1.5 miles east of the Sportsman's Club. Apparently the activity was missed or had not yet arrived on the first pass.

RaLa Shot 2 all

11/16/1954

RaLa shot # 172 took place at 1500 hours. The shot involved 2440 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the E. The maximum radiation measured at distance was 0.3 mR/h 3.5 miles; 0.2 mR/h at 5 miles. The team began a clockwise perimeter survey at 1538 and encountered fallout in Guaje Canyon about 1.1 mile west of State Road 4 with a maximum of 0.2 mR/h at 1 mile west of State Roads 4. The team checked Totavi, background, and then started north on the Espanola Road (State Road 5). Very low readings (0.04 to 0.075 mR/hr) were found in the first 1.9 miles north of State Road 4 and 5 junction. The team returned west up Guaje Canyon; the measured maximum of 0.3 mR/h was again found 1 mile up canyon, essentially the same as before. Background seemed quite variable on this survey.

RaLa Shot 2 all

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-14
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 13 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

12/2/1954

RaLa shot # 173 took place at 1645 hours. The shot involved 1585 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the NNW. The maximum radiation measured at distance was 1 mR/h at 1.5 miles. Team members began a clockwise survey from TA-1 before 1730; background was 0.04 to 0.05 mR/h. They encountered fallout at the Sportsman's Club, which continued for 2.5 miles; the maximum reading of 1.0 mR/h was recorded 0.5 miles west of the Rendija Canyon gate.

RaLa Shot 2 all

12/7/1954 On December 7, 1954 Room 5006 of CMR Building was found to be highly contaminated. The exhaust fan for this room is not filtered, contamination was probably released into the environment. Air Release 3493 21

12/9/1954 RaLa shot # 174 took place on 12/9/1954 at 1604 hours. The shot involved 500 Ci of RaLa with an explosive charge of 101 to 200 lbs. RaLa Shot 2 all

12/30/1954

RaLa shot # 175 took place on 12/30/1954 at 1445 hours. The shot involved 320 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud 

tracked toward the NE. No radiation was detected. The team surveyed Rendija and Guaje canyons. No readings above background were found, though spurious readings were encountered between the Sportsman's Club and the Rendija Canyon gate. These readings were explained as residual from previous shots. Although we have no fallout data on the previous shot, it seems unlikely that this explanation is valid because of the decay time.

RaLa Shot 2 all

1/1/1955 On one occasion during the year it was suspected that the city water line was contaminated due to corrosion. Tests did not detect contamination, but the repairs were made. Liquid Release 3053 53

1/6/1955

RaLa shot # 176 took place on 1/6/1955 at 1415 hours. The shot involved 134 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud 

tracked toward the NE. The maximum radiation measured at distance was 0.7 mR/h at 1.5 miles. A clockwise perimeter survey monitored Rendija and Guaje canyons as far as the well-drilling site below the Guaje pumice mine. Readings were 2 times background (0.07 mR/h) from the Rendija Canyon gate to 0.6 miles east of the gate. All other readings were background.

RaLa Shot 2 all

1/12/1955

RaLa shot # 177 took place on 1/12/1955 at 1415 hours. The shot involved 180 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud 

tracked toward the NNE. The maximum radiation measured at distance (mR/h) was 0.12 mR/h at 1.3 miles. Two surveys were made in Rendija and Guaje canyons to about I mile past the pumice mine. Twice background, 0.07 mR/h, was measured from the Rendija Canyon gate about 0.6 miles east. All other readings were background.

RaLa Shot 2 all

1/13/1955 On January 13, 1955 a ampule of americium curium mixture exploded spreading contamination on two workers. The workers rinsed off in a sink and drove to the hospital. The route to the hospital and the vehicle was decontaminated. Explosion 3489 4

3/9/1955 Uranium was released into the hood of Room 121 at TA-46 on March 9, 1954. Air Release 2383 2

3/17/1955

RaLa shot # 178 took place on 3/17/1955 at 1255 hours. The shot involved 3160 Ci of RaLa with an explosive charge of 201 to 350 lbs. The cloud tracked toward the NE. No radiation was detected. A northern perimeter survey was done in Rendija and Guaje canyons, down and back. All readings showed background activity.

RaLa Shot 2 all

3/23/1955

RaLa shot # 179 took place at 1315 hours. The shot involved 2260 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the NE. The wind speed was 8-15 mph. The maximum radiation measured at distance was 0.3 mR/h at 3 miles. A clockwise perimeter survey starting about 1400 found only background activity in Rendija and Guaje canyons. The team encountered fallout just east of Totavi (0.1 mR/h), which increased through Totavi and reached 0.3 mR/h at 0.2 miles west of Totavi and continued for 0.3 miles. The team retraced its route to check further east of Totavi to Otowi Bridge; readings showed background activity. Activity at the White Rock Y (intersection of main hill road and State Road 4) measured 0.1 mR/h; measurements taken towards and in White Rock were all background. A reading of 1 mR/h was recorded at Otowi ruins by another team. A rough map was drawn.

RaLa Shot 2 all

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-15
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 14 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

3/30/1955

RaLa shot # 180 took place at 1315 hours. The shot involved 2642 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the NE. The wind speed was 6-10 mph. The maximum radiation measured at distance was 0.6 mR/h at 2 miles. The general background activity in the Los Alamos area was elevated because of fallout from the Nevada Test Site (NTS). Background activity of 0.5 mR/h was measured in TA-1, 0.1 to 0.2 mR/h on State Road 4 to Totavi, and 0.1 to 0.15 mR/h on North and Tank (Barranca) mesas. The Guaje-Rendija survey passed the Sportsman's Club at 1415, where the background due to NTS fallout was 0.3 mR/h. The team found readings in excess of this background and attributed these readings to activity from this shot for about 1 mile west of the Guaje pumice mine to the mine.

RaLa Shot 2 all

4/7/1955

RaLa shot # 181 took place at 1522 hours. The shot involved 2080 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the N. The wind speed was 5 mph. The maximum radiation measured at distance was 0.7 mR/h at 1.2 miles. The team stalled the Rendija and Guaje canyons survey from TA-1 at 1600; encountering activity 1.9 miles past the Sportsman's Club. This activity continued for about 1 mile, with a maximum of 0.07 mR/h measured 0.1 miles east of the Rendija Canyon gate to 0.5 miles past the Guaje pumice mine. Here the team turned around and retraced its path. At 1654, the reading at the Sportsman's Club had increased to 0.075 mR/h. It was noted that “residual readings of 0.04 to 0.06 mr/hr from NTS test fallout a week ago prevailed throughout the survey area.”

RaLa Shot 2 all

4/22/1955

RaLa shot # 182 took place at 1810 hours. The shot involved 700 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the N. The maximum radiation measured at distance was 0.4 mR/h at 1.5 miles. The team began to survey Rendija and Guaje canyons at 1845; background activity was 0.03 mR/h. Activity was encountered 2.3 miles past the Sportsman's Club and continued for about 1 mile, with a maximum of 0.4 mR/h 2.3 miles past the Sportsman's Club. 

RaLa Shot 2 all

4/28/1955 RaLa shot # 183 took place at 1515 hours. The shot involved 3200 Ci of RaLa with an explosive charge of 101 to 200 lbs. RaLa Shot 2 all

5/5/1955

RaLa shot # 184 took place at 1540 hours. The shot involved 2560 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the NE. The maximum radiation measured at distance was 0.2 mR/h at 2 miles. A team surveying Rendija and Guaje canyons passed the Sportsman's Club at 1625; background was 0.02 to 0.04 mR/h. The team encountered fallout 2 miles further at Rendija Canyon gate; fallout continued to 0.7 miles past the Guaje pumice mine. A maximum reading of 0.2 mR/h was measured 0.4 miles east of the junction of Rendija and Guaje canyons. All other readings were background.

RaLa Shot 2 all

5/12/1955 On May 12, 1955 a small furnace erupted releasing an unknown quantity estimated at less than one kilogram of uranium in Room 102 of Sigma Building. Explosion 2374 6

5/12/1955 There was a tuballoy fire in Sigma Building, Room 103 on May 12, 1955. Fire 3489 10

5/12/1955 RaLa shot # 185 took place at 1625 hours. The shot involved 2100 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the NE. The wind speed was 10 mph. No radiation was detected. Rendija and Guaje canyons were surveyed. All readings showed background activity. RaLa Shot 2 all

5/20/1955

RaLa shot # 186 took place at 1845 hours. The shot involved 1470 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the NE. The maximum radiation measured at distance was 0.5 mR/h at 1.5 miles. Rendija and Guaje canyons were surveyed. Activity at the Rendija Canyon gate was 0.18 mR/h. At 0.2 miles east of the Rendija Canyon gate, the reading was 0.5 mR/h. All other readings were 0.08 to 0.1 mR/h. 

RaLa Shot 2 all

5/26/1955

RaLa shot # 187 took place at 1154 hours. The shot involved 520 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the 

N. The wind speed was 4-7 mph. The maximum radiation measured at distance was 1 mR/hr at 1.2 miles. Rendija and Guaje canyons were surveyed. All readings were background, which was noted as “elevated from previous shot.” A reading of 1 mR/h was recorded at Otowi ruins. 

RaLa Shot 2 all

6/2/1955

RaLa shot # 188 took place at 1345 hours. The shot involved 490 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the NE. The wind speed was 10 mph. The maximum radiation measured at distance was 0.16 mR/h at 1.5 miles. Rendija and Guaje canyons were surveyed. The path of fallout extended 0.3 miles west of the Rendija Canyon gate to 0.8 miles east. The highest reading was 0.16 mR/h. D. Meyer's handwritten note says, “no fallout found”; we assume he interpreted the fallout as resulting from previous shot(s).

RaLa Shot 2 all

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-16
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 15 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

7/21/1955 On July 21, 1955 some normal uranium caught fire in Room 1131. Fire 1184 466

8/3/1955 On August 3, 1955 a mock fission polonium source containing 25.2 curies of Po exploded in the basement of the Physics Building. Contamination was spread through out the Physics Building. Explosion 2377 3

8/19/1955 On August 19, 1955 an employee dropped a test tube containing one gram of normal uranium in Wing 2 of CMR Building. User Error 3489 14

9/6/1955 On September 6, 1955 a radiation contamination incident occurred in Room 1 of ML Building. Contam. Event 3489 14

9/16/1955

RaLa shot # 189 took place at 1455 hours. The shot involved 2600 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the E. The maximum radiation measured at distance was 0.2 mR/h at 2 miles. The team began a clockwise perimeter survey from Point Weather at 1500; background was 0.03 mR/h. The highest reading of 0.2 mR/h was measured at Point Weather (which must have been direct radiation from the firing pad, reading 65 R/h at a meter above the firing pad after the shot). Fallout was encountered in Guaje Canyon at the pumice mine, continuing for 1.2 miles with a maximum of 0.2 mR/h recorded 0.3 miles east of the pumice mine. 

RaLa Shot 2 all

9/28/1955 RaLa shot # 190 took place at 1631 hours. The shot involved 2600 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the NE. The wind speed was 10 mph. RaLa Shot 2 all

10/7/1955

RaLa shot # 191 took place at 1515 hours. The shot involved 2200 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the NNE. The wind speed was light. The maximum radiation measured at distance was 2 mR/h at 1.5 miles. The team began a clockwise survey from TA-1 at 1555; background was 0.03 mR/h. Fallout was encountered 1.4 miles east of the Sportsman's Club, which continued about 0.6 miles down Rendija Canyon. The team continued west up Guaje Canyon, encountering fallout 0.2 miles west up canyon; this fallout continued for 1.1 miles with a peak of 1 mR/h recorded 0.8 miles west up canyon. The team completed the survey down Guaje Canyon and returned through Totavi. All activity was background. 

RaLa Shot 2 all

10/19/1955

RaLa shot # 192 took place at 1720 hours. The shot involved 2000 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the E. The maximum radiation measured at distance was 0.5 mR/h 6 miles. The team began a counterclockwise survey past the main gate at 1800; background was 0.01 to 0.03 mR/h. The team encountered activity 0.4 miles north on Espanola Road (State Road 5), which continued for about 3 miles. A maximum reading of 0.5 mR/h was measured. The team surveyed around the gravel pits near the Rio Grande, south of Pajarito Village; a maximum of 2 mR/h probably was influenced by several particles, judging from the lower readings on State Road 5. One particle read 1.4 mR/h beta plus gamma at “contact,” and another read 11 mR/h gamma at 6 inches, using a Cutie Pie ion-chamber survey instrument. Later, photomicrographs, autoradiographs, and activity determinations of two particles were made; each particle measured over 300 microns in the longest dimension. 

RaLa Shot 2 all

10/26/1955

RaLa shot # 193 took place at 1630 hours. The shot involved 3987 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the NE. The maximum radiation measured at distance was 1 mR/h at 3 miles; 0.1 mR/h at 10 miles. The team began a counterclockwise perimeter survey from TA-1 at 1725; background was 0.03 mR/h. All readings showed background activity until 5.4 miles past Totavi on Espanola Road (State Road 5), where fallout was encountered that continued to Santa Clara Pueblo; a maximum of 0.15 mR/h was found at Puye Road. The team returned up Guaje Canyon, encountering fallout 1.8 miles west up canyon, which continued for about 1 mile. The maximum reading of 1.0 mR/h was recorded 1 mile east of the Guaje pumice mine. The remainder of the perimeter survey readings showed background activity. 

RaLa Shot 2 all

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-17
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 16 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

11/3/1955

RaLa shot # 194 took place at 1605 hours. The shot involved 3500 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the NNE. The wind speed was 7 mph. The maximum radiation measured at distance was 1.6 mR/h at 1.5 miles; 3.0 mR/h at 2 miles; 0.2 mR/h at 5 miles. The team began a clockwise perimeter survey from TA-1 at 1645; background activity was 0.04 mR/h. Fallout was encountered 2.1 miles past the Sportsman's Club and continued for about 1 mile. A maximum reading of 1.6 mR/h was recorded 0.3 miles further on. The team went west up Guaje Canyon, encountering fallout 0.3 miles up canyon. The fallout continued for about 1 mile, with a maximum of 3.0 mR/h recorded between 0.6 to 0.7 miles west up canyon. The remainder of the perimeter survey was completed down Guaje Canyon, through Totavi, and back to TA-1. All readings showed background activity. The following morning Puye Road was surveyed, with readings fluctuating between 0.1 and 0.2 mR/h from the Espanola Road (State Road 5) to the Puye Ruins. 

RaLa Shot 2 all

11/17/1955

RaLa shot # 195 took place at 1354 hours. The shot involved 1600 Ci of RaLa with an explosive charge of 20 to 100 lbs. The cloud tracked toward the 

NE. The wind speed was 8-10 mph. The maximum radiation measured at distance was 0.65 mR/h at 1.5 miles; 0.3 mR/h at 2 miles. The team began a clockwise perimeter survey from TA-1 at 1430; background was 0.03 mR/h. Fallout was encountered 0.7 miles past the Sportsman's Club and continued for 1.4 miles, with a maximum of 0.65 mR/h recorded 1.7 miles past the Sportsman's Club. The team surveyed west up Guaje Canyon; a maximum of 0.3 mR/h was recorded 2 miles up the canyon. 

RaLa Shot 2 all

11/29/1955

RaLa shot # 196 took place at 1535 hours. The shot involved 780 Ci of RaLa with an explosive charge of 20 to 100 lbs. The cloud tracked toward the 

NE. The wind speed was 5-7 mph. The maximum radiation measured at distance was 0.7 mR/h at 1.5 miles; 0.4 mR/h at 2 miles. The team began a clockwise perimeter survey from TA-1 at 1625; background was 0.03 mR/h. Fallout was encountered at the Rendija Canyon gate and continued for 0.8 miles, with a maximum of 0.7 mR/h measured 0.4 miles beyond. The fallout pattern also crossed upper Guaje Canyon with a maximum of 0.4 mR/h about a mile west up canyon. Above-background readings were recorded for about 3 miles to Guaje Canyon gate, where the team completed the survey through lower Rendija and Guaje canyons to Totavi. Only background activity was found. 

RaLa Shot 2 all

1/27/1956

RaLa shot # 197 took place at 1443 hours. The shot involved 1300 Ci of RaLa with an explosive charge of 20 to 100 lbs. The cloud tracked toward the 

E. No radiation was detected. The team began a special survey from TA-1 at 1500; background activity was 0.05 mR/h. Since the cloud remained in Bayo Canyon, the team surveyed only in the eastern part of the canyon to the Otowi ruins, recording a maximum of 0.4 mR/h at 0.3 miles west up Bayo Canyon from State Road 4. A rough sketch was made. 

RaLa Shot 2 all

2/1/1956 In 1956 approximately 1 Ci of Sr was released into Mortandad canyon when a line broke on a full tank of waste. Liquid Release 1733 20

2/11/1956 During the week of February 11, 1956 a pipe carrying water near Ten Site developed a leak releasing 35,000 gallons of contaminated water into Mortandad canyon. Liquid Release 2382 2

2/21/1956

RaLa shot # 198 took place at 1805 hours. The shot involved 2100 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the E. The maximum radiation measured at distance was 0.7 mR/h at 3 miles. The team began a clockwise perimeter survey from TA-1 at 1830; background activity was 0.05 mR/h. The picnic grounds and stables (on North Mesa), and Tank Mesa (Barranca Mesa) were surveyed; background activity was recorded. Fallout was encountered 1.1 miles past the Guaje pumice mine and continued for 1.3 miles with a maximum of 0.7 mR/h recorded 0.6 miles past the mine. 

RaLa Shot 2 all

3/1/1956

RaLa shot # 199 took place at 1540 hours. The shot involved 1400 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the NE. The wind speed was 7 mph. The maximum radiation measured at distance was 1.0 mR/h at 2 miles. The team began a counterclockwise perimeter survey from TA-1 at 1630; the background activity was 0.03 to 0.05 mR/h. Fallout was encountered in Guaje Canyon just east of the pumice mine and continued for almost 3 miles. A maximum of 1.0 mR/h was recorded about 0.2 miles past the Rendija/Guaje Y. The team returned west up Rendija Canyon, measuring 0.1 to 0.2 mR/h for about 0.8 miles. Tank Mesa (Barranca Mesa) and North Mesa were surveyed; only background activity was noted. 

RaLa Shot 2 all

3/9/1956 On March 9, 1956 a spill of uranium flowed into the bottom of the furnace in Room 21 of the Sigma Building. Contam. Event 2383 2

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-18
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 17 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

3/9/1956 RaLa shot # 200 took place at 1730 hours. The shot involved 435 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the E. The wind speed was 8-12 mph. RaLa Shot 2 all

3/14/1956 RaLa shot # 201 took place at 1345 hours. The shot involved 560 Ci of RaLa with an explosive charge of 101 to 200 lbs. No radiation was detected. The team began a counterclockwise perimeter survey from TA-1 at 1408; the background activity was 0.05 mR/h. All measurements were background. RaLa Shot 2 all

3/22/1956

RaLa shot # 202 took place at 1330 hours. The shot involved 389 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the 

NNE. The maximum radiation measured at distance was 0.15 mR/h at 2.2 miles. The survey team left TA-1 at 1420; background radiation was 0.03 mR/h. A reading of 0.04 mR/h was recorded at the picnic grounds (on North Mesa), 0.15 mR/h at “overlook of Bayo” [tip of Otowi Mesa, called also “North Ridge”—probably direct radiation from the firing pad, which was reading 40 R/h waist high above the pad shortly after the shot]. Readings on the “mesa north of previous measurement (0.15 mr/hr),” (Deer Trap Mesa, northeastern-most Barranca Mesa) were background. At 2.7 miles east of the Sportsman's Club, fallout of 0.12 mR/h was encountered. At 2.9 miles, fallout was 0.15 mR/h, and at Booster #1 (near Guaje/Rendija Y) it was 0.08 mR/h. About 0.5 miles up Guaje Canyon, fallout was 0.13 mR/h. 

RaLa Shot 2 all

4/7/1956

RaLa shot # 203 took place at 1730 hours. The shot involved 1520 Ci of RaLa with an explosive charge of 20 to 100 lbs. The cloud tracked toward the 

ESE. The wind speed was 8 mph. The maximum radiation measured at distance was 1.0 mR/h at 4 miles. The team departed TA-1 at 1812; background activity was 0.03 mR/h. Background activity was measured until the team reached the “tip of Tank Mesa [Barranca Mesa],” where the reading was 0.3 mR/h (direct radiation from the firing pad may have affected this measurement). A clockwise perimeter survey was continued. Background activity was

recorded until the Guaje Canyon road junction with State Road 4; at that point, the reading was 0.10 mR/h. Background activity was recorded further east to the junction of State Roads 4 and 5. Readings increased to 1.0 mR/h at Roy's Service Station (Totavi); continuing 0.6 miles west, only background activity was found to TA-1. The cloud did not rise above the Bayo Canyon walls and apparently followed the canyon to Totavi.

RaLa Shot 2 all

4/12/1956

RaLa shot # 204 took place at 1455 hours. The shot involved 3740 Ci of Rala with an explosive charge of 20 to 100 lbs. The cloud tracked toward the 

N. The wind speed was 12 mph. The maximum radiation measured at distance was 0.7 mR/h at 1.5 miles; 0.07 mR/h at 5.5 miles. The team began a clockwise survey from TA-1 at 1555; background activity was 0.03 mR/h. Down Rendija Canyon, 2 miles past the Sportsman's Club, the team encountered fallout measuring 0.05 mR/h, with a maximum of 0.7 mR/h recorded 2.5 miles beyond. Activity slowly decreased to background activity within half a mile. The team continued down Guaje Canyon to State Road 4 and north to Puye Road junction and then west, encountering 0.07 mR/h 6 to 6.4 miles west on Puye Road, essentially directly in line with the previous encounter in Guaje Canyon. The next morning the team monitored in Espanola, Riverside, and Fairview (areas east and north of Espanola); only background activity was detected. 

RaLa Shot 2 all

4/20/1956

RaLa shot # 205 took place at 1436 hours. The shot involved 3200 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the NNE. The wind speed was 8 mph. The maximum radiation measured at distance was 0.4 mR/h at 2.5 miles. The team began a clockwise survey from TA-1 at 1506; background activity was 0.03 mR/h. Team members encountered fallout about 0.7 miles past the Sportsman's Club. Activity was 0.09 mR/h, falling to 0.05 mR/h in the next 0.3 miles. Only background activity was found at Booster #1 (3 miles east past the Sportsman's Club) and for 2.3 miles west up Guaje Canyon. At 2.3 miles, fallout was encountered, which increased to a broad maximum of 0.4 mR/h for 0.4 miles, continued at this level for 0.4 miles, and then decreased to 0.15 mR/h at the Guaje Canyon gate.

RaLa Shot 2 all

4/26/1956

RaLa shot # 206 took place at 1140 hours. The shot involved 2195 Ci of RaLa with an explosive charge of 20 to 100 lbs. The cloud tracked toward the 

NE. The wind speed was 5 mph. No radiation was detected. The survey team left TA-1 at 1223; background activity was 0.03 mR/h. The team made the complete perimeter survey and found no readings above background. The cloud was observed to start to the north and then spread east along the canyon rim. 

RaLa Shot 2 all

5/10/1956

RaLa shot # 207 took place at 1145 hours. The shot involved 1070 Ci of RaLa with an explosive charge of 20 to 100 lbs. No radiation was detected. 

The survey team left TA-1 at 1310; background activity was 0.03 mR/h. The perimeter survey was completed with no readings above background recorded. 

RaLa Shot 2 all

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-19
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 18 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

5/21/1956

RaLa shot # 208 took place at 1300 hours. The shot involved 4,000 Ci of RaLa with an explosive charge of 20 to 100 lbs. The cloud tracked toward 

the NW. The maximum radiation measured at distance was 0.16 mR/h at 1.5 miles. The team began a clockwise perimeter survey from the Administration Building (TA-3, SM-43) at 1340 (note the new starting point); background activity was 0.03 mR/h. Fallout was encountered from 0.9 to 1.2 miles east of the Sportsman's Club, and the maximum activity was 0.15 mR/h beyond the Sportsman's Club. The team completed the survey route, finding only background activity. The cloud was observed to move to the south Bayo Canyon wall and then rise and move north. 

RaLa Shot 2 all

5/25/1956

RaLa shot # 209 took place at 1155 hours. The shot involved 4195 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the N. The maximum radiation measured at distance was 0.8 mR/h at 1.5 miles; 1.2 mR/h at 2 miles. The survey team left Point Weather at 1200 (only 5 minutes after the shot) and immediately measured 13 mR/h (probably direct radiation from the cloud, not fallout). On the continuing clockwise perimeter survey, fallout (0.1 mR/h) was encountered 1.4 miles east of the Sportsman's Club and continued above background with peaks of 0.8 mR/h at the Barranca (Rendija) gate and 1.2 mR/h 0.4 miles west up Guaje Canyon. The remainder of the survey found no activity above background. 

RaLa Shot 2 all

6/7/1956

RaLa shot # 210 took place at 1455 hours. The shot involved 2907 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the NE. The maximum radiation measured at distance was 0.7 mR/h at 1.5 miles. The team left the Administration Building (SM-43) at 1416; background activity was 0.03 mR/h to Point Weather, where the reading was 0.07 mR/h (probably a direct reading from the firing pad). Fallout was encountered 0.6 miles past the Sportsman's Club, with a maximum of 0.7 mR/h recorded 1.8 miles east. It continued above background for another 0.6 miles. The team completed surveying the rest of the perimeter, encountering only background activity. 

RaLa Shot 2 all

6/14/1956

RaLa shot # 211 took place at 1305 hours. The shot involved 1840 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the WSW. The wind speed was light (5) mph. No radiation was detected. The survey team left the Administration Building (SM-43) at 1315; background activity was 0.03 mR/h; activity at Point Weather was 0.07 mR/h. Only background activity was encountered on the perimeter survey. The section of State Road 4 road toward White Rock was also checked and background found. 

RaLa Shot 2 all

7/3/1956 On July 3, 1956 there was a criticality incident involving 58 kg U in the form of 93% U-235 as 2- and 5-mil foils. Changes were made in the reflector 

and graphite moderator and criticality was reached too quickly. 3.2 x 1016 total fissions were involved. Criticality 6206 all

10/5/1956

RaLa shot # 212 took place at 1428 hours. The shot involved 2200 Ci of RaLa with an explosive charge of 20 to 100 lbs. The cloud tracked toward the NW and N. The wind speed was 13 mph. The maximum radiation measured at distance was 1.3 mR/h at 1.5 miles; 1.3 mR/h at 2 miles. The team began a clockwise survey from the Administration Building (SM-43) at 1555; background activity was 0.03 mR/h; activity at Point Weather was 0.5 mR/h. Fallout was encountered 1.3 miles east of the Sportsman's Club and continued for 3.1 miles, with a peak between 1.0 and 1.3 mR/h recorded 2.1 miles east of the Club. Fallout also crossed Guaje Canyon beginning 0.5 miles west up Guaje Canyon and continuing above background for 2.1 miles. A maximum reading of 1.3 mR/h was recorded 1.l miles west up canyon. 

RaLa Shot 2 all

10/16/1956

RaLa shot # 213 took place at 1534 hours. The shot involved 1400 Ci of RaLa with an explosive charge of 20 to 100 lbs. The cloud tracked toward the NNW. The wind speed was 5 mph. The maximum radiation measured at distance was 0.8 mR/h at 2 miles. The team began a clockwise survey from the Administration Building (SM-43) at 1605; background activity was 0.03 mR/h. Fallout was encountered 2.4 miles east of the Sportsman's Club (0.1 mR/h) and 0.8 miles west up Guaje Canyon (0.8 mR/h). During the remainder of the clockwise perimeter survey, only background activity was detected. 

RaLa Shot 2 all

10/23/1956 On October 23, 1956; 100 mg of plutonium hexafluoride exploded in a drybox in Room 5122 of CMF 2. The material entered the exhaust system of the drybox and was vented into the filter tower for Wing 5. The filter tower filters were changed and monitored for contamination. Explosion 4055 6

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-20
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 19 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

10/27/1956

RaLa shot # 214 took place at 1420 hours. The shot involved 300 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the 

N. The wind speed was 10 mph. The maximum radiation measured at distance was 0.5 mR/h at 1.5 miles. The team began a clockwise survey from the Administration Building (SM-43) at 1501; background activity was 0.04 mR/h. Fallout was encountered 1.3 miles east past the Sportsman's Club, with a peak of 0.5 mR/h occurring 0.5 miles further on. The peak reading was caused by a one-foot-square contaminated area measuring 6 mR/h at 6 inches (probably one or more particles). 

RaLa Shot 2 all

11/1/1956

RaLa shot # 215 took place at 1023 hours. The shot involved 200 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the 

N. The wind speed was 9 mph. The maximum radiation measured at distance was 0.3 mR/h at 1.5 miles; 0.15 mR/h at 2.3 miles. The team began a clockwise survey from the Administration Building (SM-43) at 1100; background activity was 0.03 mR/h. Fallout was encountered 0.5 miles east of the Sportsman's Club, with a peak of 0.3 mR/h occurring 1.7 miles past the Sportsman's Club. Above-background readings continued to the Rendija/Guaje canyons junction and then increased west up Guaje Canyon, with a peak of 1.5 mR/h occurring 1.8 miles up the canyon and continuing above background for about 1 mile. The team completed the perimeter survey down Guaje Canyon to Highway 4 and returned to the Administration Building; only background activity was detected. 

RaLa Shot 2 all

12/5/1956

RaLa shot # 216 took place at 1500 hours. The shot involved 800 Ci of RaLa with an explosive charge of 20 to 100 lbs. The cloud tracked toward the 

N. The wind speed was 17 mph. The maximum radiation measured at distance was 1.0 mR/h at 1.5 miles. The team began a clockwise survey from the Administration Building (SM-43) at 1515; background activity was 0.03 mR/h. Fallout was encountered 1 mile past the Sportsman's Club and continued for 0.8 miles, with a peak of 1.0 mR/h occurring 1.4 miles past the Sportsman's Club. The perimeter survey was completed with positive readings recorded 1 mile east of the main gate. Peak activity of 0.4 mR/h occurred at the entrance to the East Gate Lab. No explanation was offered for these later readings, which are in the opposite direction from which the main cloud was detected. Operations at the East Gate Laboratory are suspected (see shots #238, 240, and 242). 

RaLa Shot 2 all

12/20/1956

RaLa shot # 217 took place at 1450 hours. The shot involved 225 Ci of RaLa with an explosive charge of 20 to 100 lbs. The cloud tracked toward the 

W and SW. The wind speed was 3 mph. The maximum radiation measured at distance was 1 mR/h at 0.6 miles; 0.3 mR/h at 1 mile; 0.5 mR/h at 2 miles. The team began a counterclockwise survey from the Administration Building (SM-43) at 1510; background activity was 0.05 mR/h. A reading of 0.3 mR/h was recorded at the dump site near the Los Alamos Airport. The team completed the perimeter survey; all readings showed only background activity. A town site survey began at 1700; a peak of 0.15 mR/h was recorded at the eastern end of Manhattan Loop (eastern residential area). Activity up to 0.075 mR/h was recorded at the DP Road trailer court (south of the airport). At 0.1 miles west of Point Weather, activity from 1 mR/h to 0.5 mR/h was recorded to the ballpark (on North Mesa), where background activity was measured. 

RaLa Shot 2 all

2/7/1957 On February 7, 1957 an explosion and fire occurred in the pure metal drybox in Room 406 of DP West. The only contamination found was on the outside of the air intake filters. Explosion 4056 162/8/1957 On February 8, 1957 tinners disconnected the exhaust duct on the wooden drybox line in Room 500. Highly contaminated dust spread throughout the south part of the room. Air Release 3490 11

2/12/1957 At 3 pm on February 12, 1957 the Godiva assembly located at Kiva 2 at Pajarito Site went supercritical. Filters in the heating system were found to be highly contaminated. The exhaust system was not running at the time of the incident. Criticality 2817 1-2

2/12/1957 On February 12, 1957 there was a criticality incident involving 54 kg U metal 93% U-235 due to incorrect operation at the Lady Godiva reactor. 

There was warping oxidation near melting close to center. 1.2 x 1017 total fissions were involved. Criticality 6206 all

3/7/1957 On March 7, 1957 a worker in Room 2125 Wing 2 of CMR Building was working with 20 grams of plutonium in a glovebox when they noticed that there was a leak in the glove. Air Release 3490 19

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-21
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 20 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

3/16/1957 RaLa shot # 218 took place at 1245 hours. The shot involved 2140 Ci of RaLa with an explosive charge of 20 to 100 lbs. The cloud tracked toward the N. The wind speed was 15 mph. RaLa Shot 2 all

3/27/1957 On March 27, 1957 an explosion occurred in the machine lathe drybox in Room 500. The operator of the lathe was highly contaminated. After showering no contamination was detected. Explosion 3490 23

3/29/1957

RaLa shot # 219 took place at 1250 hours. The shot involved 3079 Ci of RaLa with an explosive charge of 20 to 100 lbs. The cloud tracked toward the 

E. The wind speed was 6 mph. The maximum radiation measured at distance was 0.1 mR/h at 3 miles; 0.07 mR/h at 7 miles. The team began a counterclockwise survey from the Administration Building (SM-43) at 1330; background activity was 0.03 mR/h. A reading of 0.1 mR/h was recorded at the stables (on North Mesa), but it was questioned on the survey sheet as not being reasonable, probably because the cloud was reported to have gone to the east. Fallout of 0.07 mR/h was encountered in Guaje Canyon 0.7 miles past the pumice mine, continuing for about 0.5 miles, with a peak of 0.1 mR/hr halfway between. Activity between 0.5 and 0.07 mR/h was recorded north on State Road 5, 3.2 miles from the junction. 

RaLa Shot 2 all

4/17/1957

RaLa shot # 220 took place at 1630 hours. The shot involved 3249 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the E. The wind speed was 12 mph. The maximum radiation measured at distance was 0.4 mR/h at 4.5 miles. The team left the Administration Building (SM-43) at 1650; background activity was 0.03 mR/h. During the counterclockwise perimeter survey, fallout (0.04 mR/h) was encountered at the junction of the Main Hill Road/ White Rock cutoff. It increased to a maximum of 0.4 mR/h at 0.3 miles before the junction of Guaje Canyon and State Road 4. At Otowi Bridge, activity was 0.08 mR/h; at the Espanola Highway (State Road 5) to Puye Road, it was 0.08 to 0.09 mR/h for 3 miles. At the entrance to Guaje Canyon, activity was 0.2 mR/h and persisted to the Guaje pumice mine, where the 0.08 mR/h reading was attributed to contamination on the vehicle since the reading continued at this level until the team returned to the Administration Building. Weather observations confirmed that the cloud did not rise above the canyon walls to reach the southwest winds. 

RaLa Shot 2 all

5/9/1957

RaLa shot # 221 took place at 1600 hours. The shot involved 1000 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the SE. The wind speed was 7 mph. No radiation was detected. The team began a clockwise survey from Administration Building (SM-43) at 1630; background activity was 0.04 mR/h. A clockwise perimeter survey was completed that included Puye Road; no measurable fallout was detected. Weather observations of the cloud support these findings. The cloud remained in Bayo Canyon. 

RaLa Shot 2 all

6/5/1957 There was a fire in the back of a contaminated dump truck on June 5, 1957. Fire 3490 23

6/13/1957 On June 13, 1957 there was a contamination incident in Room 513 of DP West. The contamination occurred during the cleaning out of a Lucite casting tunnel. Contam. Event 3490 49

6/20/1957

RaLa shot # 222 took place at 1540 hours. The shot involved 1000 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the NE. The wind speed was 12 mph. No radiation was detected. The team left the Administration Building (SM-43) at 1625; background was 0.03 mR/h. A counterclockwise survey included the Puye pumice mine; the survey team returned through Guaje Canyon. The recorded instrument readings fluctuated between 0.02 and 0.05 mR/h but were considered negative. Weather observations confirmed that the cloud remained in the canyon. 

RaLa Shot 2 all

7/10/1957

RaLa shot # 223 took place at 1625 hours. The shot involved 2257 Ci of RaLa with an explosive charge of 20 to 100 lbs. The cloud tracked toward 

the NNW. The wind speed was 8 mph. The maximum radiation measured at distance was 0.6 mR/h at 1.5 miles. The team began a clockwise survey from Administration Building (SM-43) at 1640; background activity was 0.05 mR/h. Fallout was encountered 0.4 miles east past the Sportsman's Club, with a maximum of 0.6 mR/h recorded just beyond and falling to background 0.8 miles past the Sportsman's Club. 

RaLa Shot 2 all

7/11/1957 On July 11, 1957 a leak was discovered in the buried acid waste tank outside Building #35 DP West. The contaminated ground was dug up and put into metal containers to be disposed of in the contamination dump. Liquid Release 721 49

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-22
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 21 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

7/23/1957

RaLa shot # 224 took place at 1306 hours. The shot involved 1520 Ci of RaLa with an explosive charge of 20 to 100 lbs. The cloud tracked toward 

the N. The wind speed was 8 mph. The maximum radiation measured at distance was 0.6 mR/h at 1.5 miles; 1.0 mR/h at 2.2 miles; 0.08 mR/h at 4 miles. The team began a clockwise survey from Administration Building (SM-43) at 1335; background activity was 0.05 mR/h. Fallout was encountered 1.2 miles east past the Sportsman's Club, with a maximum of 0.6 mR/h recorded 1.4 miles past the Sportsman's Club. The same reading was recorded 2.0 miles past the Sportsman's Club. A reading of 1.0 mR/h was recorded 1.6 miles west up Guaje Canyon; 0.08 mR/h was recorded at the Puye pumice mine, although the same reading was recorded at the Administration Building, which does not seem reasonable. Contamination on the detector or the vehicle is suspected. 

RaLa Shot 2 all

8/15/1957 On August 15, 1957 an explosion occurred in a glove box chain in Room 500. 18 rubber gloves were torn and three safety windows were cracked. Five men were contaminated, no skin contamination was detected after showering. Explosion 4056 8

8/16/1957 On August 16, 1957 an explosion occurred in a glovebox chain in Room 500. Five men were contaminated with Pu. Explosion 3490 538/30/1957 On August 30, 1957 large quantities of plutonium contamination were dispersed over the floor, hood and sink in three labs in J-11, contamination was also detected in the J-2 Building hallway. Air Release 2413 49/27/1957 On September 27, 1957 rags contaminated with sodium and uranium caught fire in Room 133 at Ten Site. Fire was quickly extinguished with CO2. Fire 2414 3

9/27/1957

RaLa shot # 225 took place at 1607 hours. The shot involved 1960 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the N. The maximum radiation measured at distance was 0.8 mR/h at 1.5 miles. The team began a clockwise survey from the Administration Building (SM-43) at 1707; background activity was 0.05 mR/h. Fallout was encountered 1.4 miles east past the Sportsman's Club, with a maximum of 0.8 mR/h recorded 1.5 miles past the Sportsman's Club.

RaLa Shot 2 all

10/10/1957

RaLa shot # 226 took place at 1726 hours. The shot involved 1153 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the NE. The wind speed was 7 mph. The maximum radiation measured at distance (mR/h) was 0.3 mR/h at 2.2 miles. The team began a clockwise survey and reached the Sportsman's Club at 1814; background activity was 0.03 mR/h. Fallout was encountered 0.2 miles past the Rendija/Guaje junction, with a maximum of 0.3 mR/h recorded 0.4 miles down canyon. Activity continued above background until past the Guaje pumice mine. During the rest of the survey, only background activity was recorded. 

RaLa Shot 2 all

11/12/1957 On November 12, 1957, a vial containing 14,000 c/m of plutonium was dropped at the stairs leading from the first floor of HRL Building. User Error 2489 3

1/30/1958

RaLa shot # 227 took place at 1302 hours. The shot involved 1340 Ci of RaLa with an explosive charge of 20 to 100 lbs. The cloud tracked toward 

the E. The wind speed was 13 mph. The maximum radiation measured at distance was 0.16 mR/h at 3 miles. The team began a clockwise survey from the Administration Building (SM-43) at 1343; background activity was 0.02 mR/h. Fallout was encountered at Well #1 and continued for 1.8 miles, with a maximum of 0.16 mR/h recorded 1.3 miles west up canyon from State Road 4. 

RaLa Shot 2 all

2/19/1958

RaLa shot # 228 took place at 1545 hours. The shot involved 1850 Ci of RaLa with an explosive charge of 20 to 100 lbs. The cloud tracked toward 

the NNW. The wind speed was 5 mph. The maximum radiation measured at distance was 5 mR/h at 1.5 miles. The team began a clockwise survey from the Administration Building (SM-43) at 1625; background activity was 0.02 mR/h. Fallout was encountered at the Sportsman's Club, with a maximum of 5 mR/h recorded one mile east past the Sportsman's Club. Above background readings continued to Booster #2 at the junction of Rendija and Guaje canyons. 

RaLa Shot 2 all

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-23
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 22 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

3/7/1958

RaLa shot # 229 took place at 1655 hours. The shot involved 1800 Ci of RaLa with an explosive charge of 20 to 100 lbs. The cloud tracked toward 

the NNW. The maximum radiation measured at distance was 1.0 mR/h at 1.5 miles. The team began a clockwise survey from the Administration Building (SM-43) at 1743; background activity was 0.03 mR/h. Fallout was encountered 1.9 miles east past the Sportsman's Club, with a maximum of 1.0 mR/h recorded 2.1 miles past the Sportsman's Club. Above-background activity was recorded to the junction of Rendija/ Guaje canyons. 

RaLa Shot 2 all

4/3/1958

RaLa shot # 230 took place at 1505 hours. The shot involved 1100 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the NW, NE. The wind speed was 5 mph. No radiation was detected. The team began a clockwise survey from the Administration Building (SM-43) at 1535 for a clockwise perimeter survey. All readings showed background activity. 

RaLa Shot 2 all

5/1/1958 RaLa shot # 231 took place at 1430 hours. The shot involved 1134 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the NNW. The wind speed was 10 mph. RaLa Shot 2 all6/3/1958

RaLa shot # 232 took place at 1450 hours. The shot involved 1316 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the NE. The wind speed was 12 mph. The maximum radiation measured at distance was 0.18 mR/h at 2 miles. The team began a clockwise survey from

the Administration Building (SM-43) at 1535; background activity was 0.05 mR/h. Fallout was encountered at the Rendija/Guaje junction, with a maximum of 0.18 mR/h recorded 0.7 miles down canyon. The remainder of the survey recorded background activity. 

RaLa Shot 2 all

7/25/1958 On July 25, 1958 at TA-33, a leak occurred in Building 86 causing tritium to be released. The site was evacuated and road blocks were set up. Air Release 2422 47/25/1958 Large quantities of tritium were released in the filling chamber of Room 9 at TA-33 on July 25, 1958. It was estimated that 13,000 curies were lost. Air Release 4057 20

10/28/1958 A fire was detected on October 28, 1958 in pit #6 of the contaminated dump. Fire 4057 27

11/6/1958 On November 6, 1958 K Division members were removing a plutonium pilot plant from the air filter building, contamination was spread to the floor, wheels of the fork lift, and the dirt east of the building. Contam. Event 2510 3

12/8/1958

RaLa shot # 233 took place at 1545 hours. The shot involved 1305 Ci of RaLa with an explosive charge of 20 to 100 lbs. The cloud tracked toward 

the N. The maximum radiation measured at distance was 1.4 mR/h at 1.5 miles. The team began a clockwise survey from the Administration Building (SM-43) at 1600; background activity was 0.03 mR/h. Fallout was encountered, twice background, in the “new housing area” (Barranca Mesa), and 1.0 mR/h was recorded at the end of Tank Mesa (Barranca Mesa, overlooking the firing site). Back on the clockwise perimeter survey route, fallout was encountered 1.2 miles east past the Sportsman's Club, with a maximum of 1.4 mR/h recorded at the Guaje Canyon gate. The remainder of the survey route showed background activity. 

RaLa Shot 2 all

12/30/1958 On December 30, 1958 there was a criticality incident involving 3.27 kg Pu Pu02(N03)2 in ~168 liters of water. The cylinder contained dissolved Pu, 

when the agitator was stared it created critical geometry. One death resulted from the accident. 1.5 x 1017 total fissions were involved. Criticality 6206 all

2/20/1959

RaLa shot # 234 took place at 1335 hours. The shot involved 1250 Ci of RaLa with an explosive charge of 20 to 100 lbs. The cloud tracked toward the N. The maximum radiation measured at distance was 0.18 mR/h at 1.5 miles. The team began a clockwise survey from the Administration Building (SM-43) at 1405; background activity was 0.04 mR/h. Fallout was encountered 0.5 miles past the Sportsman's Club and continued for 2 miles, with a maximum of 0.18 mR/h recorded at Booster #2, which is 1.2 miles east of the Sportsman's Club. 

RaLa Shot 2 all

3/13/1959

RaLa shot # 235 took place at 1405 hours. The shot involved 1070 Ci of RaLa with an explosive charge of 20 to 100 lbs. No radiation was detected. The team left the Administration Building (SM-43) at 1426; background activity was 0.05 mR/h. The team completed the counterclockwise survey; all readings showed background activity. 

RaLa Shot 2 all

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-24
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 23 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

3/17/1959 On March 17, 308 curies of tritium were released to the outside when a valve on a Van de Graff was left open. Air Release 2739 3

4/1/1959 During processing of irradiated U-235 at TA-48 uranium oxide was blown out of the hood when a sample can was opened. Explosion 2514 4

4/2/1959

RaLa shot # 236 took place at 1635 hours. The shot involved 980 Ci of RaLa with an explosive charge of 20 to 100 lbs. The cloud tracked toward the 

ESE. The maximum radiation measured at distance was 0.6 mR/h at 3 miles. The team left the Administration Building (SM-43) at 1750 to conduct a clockwise survey; background activity was 0.03 to 0.04 mR/h. Fallout was encountered at the intersection. The fallout continued west along State Road 4 for 3 miles, with a maximum of 0.6 mR/h recorded 1.5 miles west of the Guaje/State Road 4 intersection (12 mR/h was recorded at an isolated spot). The remainder of the survey showed background activity. The cloud was observed to go over the north Bayo Canyon wall. 

RaLa Shot 2 all

4/14/1959

RaLa shot # 237 took place at 1250 hours. The shot involved 1140 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the N. The maximum radiation measured at distance was 0.4 mR/h at 1.7 miles. The team left the Administration Building (SM-43) at 1401; 

background activity was 0.03 to 0.04 mR/h. Fallout was encountered 1.2 miles past the Sportsman's Club, and readings remained elevated to the White Rock junction on State Road 4. A maximum of 0.4 mR/h was recorded 2 miles past the Sportsman's Club. 

RaLa Shot 2 all

5/1/1959

During the operation of LAMPRE II radioactive gas was released through the exhaust system, causing an increase in background levels around the town site. High background levels were detected in the water boiler reactor room due to a disconnected exhaust pump in the valve house, the incident increased background levels around the town site.

Air Release 2515 4

5/15/1959

RaLa shot # 238 took place at 1547 hours. The shot involved 1040 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the ESE. The team left the Administration Building (SM-43) at 1640; background activity was 0.03 to 0.05 mR/h. A clockwise survey was conducted; only background activity was recorded until fallout was encountered on the Main Hill Road 0.8 miles east of the main gate for about 0.6 miles. A maximum of 1.5 mR/h was recorded beyond the East Gate Laboratory at the entrance to the Camp Hamilton Trail. Because the cloud was reported to go down canyon (east-southeast), the readings are not believed to be related to the Bayo Canyon activity. During this period, a large 120-curie cobalt60 source located about 400 feet directly north of the Main Hill Road at the East Gate Laboratory (TA-19) was in intermittent use and is believed to explain these readings (see also shots #240 and #242). 

RaLa Shot 2 all

6/4/1959

RaLa shot # 239 took place at 1527 hours. The shot involved 995 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the 

ENE. The maximum radiation measured at distance was 0.4 mR/h at 2.7 miles. The team left the Administration Building (SM-43) at 1630; background activity was 0.04 mR/h. During the clockwise survey, above-background activity was encountered at Booster #1, 3 miles east of the Sportsman's Club. It continued for 1.4 miles, with a maximum reading of 0.4 mR/h recorded 3.8 miles past the Sportsman's Club. 

RaLa Shot 2 all

6/26/1959

RaLa shot # 240 took place at 1400 hours. The shot involved 954 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the 

E. The maximum radiation measured at distance was 0.12 mR/h at 2.5 miles. The team began a clockwise survey from the Administration Building (SM-43) at 1419; background activity was 0.02 mR/h. Fallout was encountered at the Guaje pumice mine and continued for 1.6 miles, with a maximum of 0.12 mR/h recorded 0.8 miles past the mine. Fallout was encountered again on the Main Hill Road 1.3 miles east of the main gate, with a maximum of 1.3 mR/h recorded 0.5 miles east of the gate. Because the cloud was reported to have gone over the north wall of Bayo Canyon, this reading is again attributed to the gamma source at the East Gate Laboratory (see shots #238 and #242). 

RaLa Shot 2 all

7/15/1959 On July 15, 1959 a fire broke out in a plutonium contaminated CWS exhaust filter during welding of a new section of exhaust duct on the discharge side of the filter unit. Fire 19 55

7/15/1959 On July 15, 1959 a fire broke out in a plutonium contaminated CWS exhaust filter in Room 501 DP West. Highly contaminated ash was dispersed through out the room. The clothes of 12 firemen were held for decontamination. Fire 2425 5, 6

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-25
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 24 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

7/17/1959 Tritium gas was released from a storage tank reservoir in Building 86 at TA-33 on July 17, 1959. Road blocks were established and 69 people were evacuated from the area. No appreciable radiation was measured outside the fence of Building 86. Air Release 2425 5, 68/14/1959 On August 14, 1959 a tritium leak occurred at P-9 Van de Graff area when an "o" ring allowed tritium to be released. Air Release 2426 3

10/7/1959

RaLa shot # 241 took place at 1438 hours. The shot involved 893 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the 

ENE. The wind speed was 12 mph. The maximum radiation measured at distance was 0.12 mR/h at 3 miles. The team began a clockwise survey from the Administration Building (SM-43) at 1603; background activity was 0.05 mR/h. Questionable activity (only 0.01 mR/h over background) was encountered at Booster #1 for 4.2 miles, with a maximum of 0.12 mR/h recorded 1.5 miles past the Guaje pumice mine. During the remainder of the survey, only background activity was recorded. 

RaLa Shot 2 all

10/14/1959 Explosion occurred while disposing of scrap and waste explosives Explosion NA 58

12/3/1959 On December 3, 1959 a fire broke out in an incinerator dry box exhaust system. A neoprene duct connection had burned out releasing contamination to the roof. Fire 19 57

12/3/1959 On December 3, 1959, a fire broke out in the duct work of Room 313 of DP West where uranium materials are incinerated. The damage was limited to the duct work. Fire 2494 3

12/3/1959 A fire occurred on December 3, 1959 in the drybox exhaust ductwork in Room 313 of DP West during the burning of U-235 contaminated rags. The exhaust stack discharged black smoke toward the west for approximately 15 minutes. Alpha contamination was detected downwind of Room 313. Fire 4058 1

12/16/1959 On December 16, 1959 a filter in the vent line of the neutralization tank at the waste treatment operation at DP West failed allowing plutonium and americium to run down the roof and contaminate the ground. Liquid Release 2494 3

1/15/1960

On January 15, 1960 in Room 308 of DP West a bottle containing plutonium solution had shattered. Contamination was tracked into the main hallway and into Room 206 and 363. Airborne contamination spread into 313, 322 and 326. the air supply room on the south side of Building 3 was monitored and found to be highly contaminated.

Liquid Release 3971 18

2/3/1960 Two different explosions occurred in the rag incinerator in Room 313 of DP West on January 28, 1960 the other on February 3, 1960. Explosion 2496 32/3/1960 On February 3, 1960 in Room 313 of DP West an explosion occurred during the burning of U-235 contaminated rags. The area was monitored and no surface contamination was detected. Explosion 3971 14

3/8/1960

RaLa shot # 242 took place at 1648 hours. The shot involved 908 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the 

S. The maximum radiation measured at distance was 0.4 mR/h at 2.5 miles. The team began a counterclockwise survey from the Administration Building (SM-43) at 1717; background activity was 0.03 mR/h. Since the cloud was observed to travel down canyon, the activity that was encountered 1.7 miles east of the airstrip and continued for about 0.5 miles, with a maximum of 1.5 mR/h recorded 1.9 miles past the airstrip, is believed to be due to the gamma source at the East Gate Laboratory (see shots #238 and #240 above). The remaining readings, beginning about 1.5 miles west of Roy's Service Station (Totavi) and continuing for about 1.3 miles, are attributable to this shot. A maximum reading of 0.4 mR/h was recorded 0.9 miles west of Roy's Service Station. 

RaLa Shot 2 all

4/13/1960 On April 13, 1960 in Building HP 21 there was widespread plutonium contamination when 100mg of plutonium was released during an experiment. Contam. Event 2498 4

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-26
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 25 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

5/4/1960

RaLa shot # 243 took place at 1618 hours. The shot involved 957 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward the 

ENE. The maximum radiation measured at distance was 1.3 mR/h at 2.1 miles. The team began a clockwise survey from the Administration Building (SM-43) at 1645; background activity was 0.02 to 0.03 mR/h. Fallout was encountered 0.7 miles west of Well #1 and continued for 2.5 miles, with a maximum of 1.3 mR/h recorded 1.3 miles past Well #1. At Well #1, a particle was collected reading 1100 mR/h at “contact” with a Cutie Pie (an ionization chamber instrument). Background readings during this survey seemed to fluctuate. The environmental group reported results of two film badge dosimeters planted at the airstrip, about 1 mile southwest of the firing site, for a period beginning 22 days before and ending 30 days after this shot. They reported the readings averaged 200 mR/mr over this period and attributed the dose to a possible particle from the main cloud, although the main cloud went in the opposite direction. 

RaLa Shot 2 all

6/17/1960 On June 17, 1960 there was a criticality incident involving ~48 kg U-235. Uranium cylinders in thick graphite (9-in.) reflected before complete 

assembly, resulting in trivial damage. 6 x 1016 total fissions were involved. Criticality 6206 all

9/1/1960

RaLa shot # 244 took place at 1300 hours. The shot involved 1120 Ci of RaLa with an explosive charge of 101 to 200 lbs. The cloud tracked toward 

the N and NW. The maximum radiation measured at distance was 0.3 mR/h at 1.2 miles; 0.3 mR/h at 2 miles. The team began a clockwise perimeter survey from the Administration Building (SM-43) at 1325; background activity was 0.05 mR/h. Fallout was encountered 0.8 miles east past the Sportsman's Club and continued for 0.8 miles, with a maximum of 0.3 mR/h recorded 1.1 miles past the Sportsman's Club; 2.1 miles west up Guaje Canyon the maximum was 0.3 mR/h. A resurvey the next morning found a “speck” reading of 1.1 mR/h at “contact” on Guaje Road, where the maximum reading was found the day before.

RaLa Shot 2 all

9/14/1960 September 14, 1960 15-30 gallons of americium raffinate spilled from a tank at Building 35 DP West. A trailer and the ground outside of the americium treatment Building were contaminated and cleaned. Liquid Release 2429 5

9/16/1960 On September 16, 1960 approximately 15-30 gallons of Am raffinate spilled in Building 35 DP West. The equipment trailer and the south side of the Building and ground surrounding the trailer were contaminated. Liquid Release 3971 8

9/21/1960 On September 21, 1960 a small explosion occurred in the Room 201 incinerator. The room was decontaminated the following day. Explosion 3971 7

10/11/1960 RaLa shot # 245 took place at 1408 hours. The shot involved 1100 Ci of RaLa with an explosive charge of 20 to 100 lbs. The team started a survey on Barranca Mesa, completing a clockwise route. All readings were recorded as “00.” RaLa Shot 2 all

11/22/1960 RaLa shot # 246 took place at 1214 hours. The shot involved 1475 Ci of RaLa with an explosive charge of 101 to 200 lbs. For this experiment, the configuration was such that the RaLa source remained intact. There was no dispersion of radioactive material. RaLa Shot 2 all

2/17/1961 RaLa shot # 247 took place at 1650 hours. The shot involved 7090 Ci of RaLa with an explosive charge of 20 to 100 lbs. For this experiment, the configuration was such that the RaLa source remained intact. There was no dispersion of radioactive material. RaLa Shot 2 all

3/24/1961

On March 24, 1961 a contamination incident occurred during the disassembly of a drybox on a milling machine. The turntable was taken to the contaminated truck for wrapping. The turntable was opened to facilitate further wrapping and in doing so some plutonium dust was released. A strong gust of wind blew spread contamination to the truck, the adjacent building, and surrounding ground. A large airborne count of alpha contamination was measured in Building 54 during the incident.

Air Release 19 85

3/24/1961 On March 24, 1961, during removal of equipment at DP West an undetermined, but visible release of plutonium occurred. Air Release 2520 43/24/1961 On March 24, 1961 a contamination incident occurred in Building 54 of DP Site, resulting in the spread of plutonium dust contamination. The incident occurred during the removal of a glove box from a milling machine. Air Release 4059 15

5/19/1961 RaLa shot # 248 took place at 1314 hours. The shot involved 3902 Ci of RaLa with an explosive charge of 20 to 100 lbs. For this experiment, the configuration was such that the RaLa source remained intact. There was no dispersion of radioactive material. RaLa Shot 2 all

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-27
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 26 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

6/20/1961 RaLa shot # 249 took place at 2019 hours. The shot involved 5300 Ci of RaLa with an explosive charge of 20 to 100 lbs. For this experiment, the configuration was such that the RaLa source remained intact. There was no dispersion of radioactive material. RaLa Shot 2 all

8/7/1961 On August 7, 1961 a container with a uranium fuel element leaked. Contamination products were detected in the parking lot and around the building. No decontamination was done. Air Release 2524 4

9/28/1961

On September 28, 1961 a spill occurred in the liquid waste sampling room located in the northeast of Building 2, DP West. The drain line stopped up and contaminated liquid flowed down the storm drain. Workmen from Room 326 had walked through the area. Their homes and personal shoes were monitored and no contamination was detected.

Liquid Release 4059 10

10/11/1961 RaLa shot # 250 took place at 1302 hours. The shot involved 3870 Ci of RaLa with an explosive charge of 20 to 100 lbs. For this experiment, the configuration was such that the RaLa source remained intact. There was no dispersion of radioactive material. RaLa Shot 2 all

11/17/1961 RaLa shot # 251 took place at 1430 hours. The shot involved 4150 Ci of RaLa with an explosive charge of 20 to 100 lbs. For this experiment, the configuration was such that the RaLa source remained intact. There was no dispersion of radioactive material. RaLa Shot 2 all

11/28/1961 On November 28, 1961 a spill was discovered on the ground north of the pump house of Building 700. The spill was monitored and contamination was found. Liquid Release 4059 412/10/1961

The GNOME nuclear test, the first test in the Plowshare Program, was conducted near near Carlsbad, NM. The device was placed at a depth of 1,185 

ft in a shaft drilled in salt. The objectives of the 3 kiloton test were isotope recovery, neutron physics experimentation, examination of heat recovery, seismic measurements, and explosive development. The shot also had a Vela Uniform Program objective to determine how the seismic signals and effects of a 3-kiloton device detonated underground in salt beds differed from the outputs of detonations of different yields in other geologic formations such as tuff and granite and from signals caused by earthquakes. [Ref: http://www.nv.doe.gov/library/films/fulltext/0800034.htm and https://www.osti.gov/opennet/reports/plowshar.pdf]

1/30/1962 RaLa shot # 252 took place at 1908 hours. The shot involved 6077 Ci of RaLa with an explosive charge of 20 to 100 lbs. For this experiment, the configuration was such that the RaLa source remained intact. There was no dispersion of radioactive material. RaLa Shot 2 all

2/2/1962 RaLa shot # 253 took place at 1341 hours. The shot involved 1590 Ci of RaLa with an explosive charge of 20 to 100 lbs. For this experiment, the configuration was such that the RaLa source remained intact. There was no dispersion of radioactive material. RaLa Shot 2 all3/6/1962 RaLa shot # 254 took place at 1330 hours. The shot involved 5940 Ci of RaLa with an explosive charge of 20 to 100 lbs. For this experiment, the configuration was such that the RaLa source remained intact. There was no dispersion of radioactive material. RaLa Shot 2 all

3/9/1962 On March 9, 1962 .8 g of tritium were released into the atmosphere during an experiment at TA-41. Air Release 4060 8

12/11/1962 On December 11, 1962 there was a criticality incident involving U-235 foils in graphite. The assembly went critical when it was ran due to 

inadequate communication between work crews. 3 x 1016 total fissions were involved. Criticality 6206 all

2/27/1963 On February 27, 1963 approximately 48 millicuries if radioactive iodine was release out the stack of Cell 9, Wing 9, CMR Building. Air Release 4061 18

3/4/1963 On March 4, 1963 radioactive I-131 was released from Stack #2. Air Release 2072 1504/8/1963 On April 8, 1963 there was a uranium spill at TA-46. Contam. Event 2536 26/1/1963 A glovebox was torn in a drybox at DP West during a routine operation, releasing plutonium into air. Fire 2538 36/1/1963 During maintenance, a spark from a welding operation started a fire in the filter of a plutonium drybox, releasing plutonium into air. Fire 2538 36/6/1963 On June 6, 1963 a fire occurred in a drybox air intake filter in Room 213 of DP West. No contamination was detected in the vicinity of the drybox. Fire 4061 16

7/31/1963 On July 31, 1963 an employee spilled some contaminated material from a U-235 rag incinerator onto the hood and floor of Room 313 DP West. Contam. Event 4061 9

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-28
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 27 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

11/15/1963 On November 15, 1963 P-9 accidentally released 2 cc of tritium gas. Air Release 2502 411/26/1963 On November 26, 1963 a worker was found to have contamination on his clothing. His personal car and home were monitored and no contamination was found. User Error 4061 2

1/10/1964 On January 10, 1964 in SM-66 depleted uranium residue ignited in a drum. The material was allowed to burn out. Fire 2812 32/11/1964 Omega Site was contaminated when a sample reading 4.5 R/hr at 1 m was removed from OWR vertical port and dragged down the road (because of its weight) to the storage area. Contam. Event 2812 3

4/12/1964 An explosion occurred in Room 313 rag incinerator drybox following ignition of a batch of U-235 contaminated rags on April 12, 1964. The fire spread from the drybox into the adjoining hood and ignited another batch of rags. The fire was quickly extinguished. Explosion 11 297

4/22/1964 An explosion occurred following a fire in Room 313 DP West from uranium contaminated rags on April 22, 1964. The fire spread from the drybox to the adjoining hood. Fire 2505 4

4/22/1964 On April 22, 1964 an explosion occurred in an incinerator drybox in Room 313 of DP West during the incineration of U-235 contaminated rags. Explosion 4062 5

7/2/1964 Explosion attributed to accumulation of unburned gas in area of stagnant air movement in furnace upper passageways, damaged boiler furnace Explosion NA 78

7/31/1964 On July 31, 1964 high levels of contamination were detected in a hood after an accidental plutonium release. The hood was decontaminated, but the stack was likely contaminated. Air Release 2507 4

10/3/1964 On October 3, 1965 there was a tritium release at P-9. Approximately 100 curies of tritium was released. Air Release 4063 3

11/11/1964 On November 11, 1964 there was a fire in pit 3 of area G (Mesita del Buey). The cause of the fire is unknown. Fire 4062 5

2/16/1965 On February 16, 1965 approximately two liters of tritium gas were released up the stack during an experiment. Air Release 4063 122/17/1965 On February 17, 1965; 10 curies of tritium was released into Room 4130 during an experiment. Air Release 2072 2612/17/1965 An estimated 10 Ci of tritium were released on February 17, 1965 from the hood in Room 4130 of CMF-4. Air Release 4063 124/14/1965 On April 14, 1965 in Building 35 sludge filtering room, approximately 25 gallons of contaminated sludge spilled when a pipefitter disconnected a flange in the sludge filtering tank. The area was quickly decontaminated. Liquid Release 4063 12

5/28/1965 On May 28, 1965 at White Sands Missile Range there was a criticality incident involving 96 kg enriched U-Mo alloy, due to incorrect operation. The 

assembly bolts broke, and there was minor damage to coating. 1.5 x 1017 total fissions were involved. Criticality 6206 all

6/1/1965 At DP East the gas purge line to a recovery furnace became plugged. The operator in charge removed a rubber hose connected to the unit, and uranium-containing dust was blown out into his face and onto his clothing. User Error NA 2

12/1/1965 During the removal of a rod coated with Am-241 from an experimental apparatus, personal clothing of the operator was contaminated. User Error NA 44/15/1966 On April 15 and 16, 1966 there was a "large spill" of tritium at P-9 due to a diaphragm failure. Air Release 4064 65/11/1966 An explosion occurred in a rag incinerator globe box in the U-235 recovery area at DP West. The explosion cracked the window of the glove box. Explosion NA 4-5

6/9/1966 On June 9, 1966 there was a tritium spill at P-12. Air Release 4064 6

11/16/1966 The air cleaner at one of the enriched uranium shops developed a pin-hole leak, which resulted in high surface contamination of the surrounding area. Air Release NA 3

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-29
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 28 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

7/14/1967

A fire occurred on July 14, 1967 in Room 313 of DP West. Sparks from the incinerators escaped and ignited the pre-filter located in a well in the loading drybox floor. The flames swept up the exhaust line and ignited the HEPA filter in the drybox. The Building 3 roof was monitored and no contamination was detected.

Fire 4065 10

12/1/1967 An explosion occurred in the rag-incinerator drybox in Room 313 DP West on Dec. 1, 1967 during the incineration of U-238 contaminated rags. Explosion NA 4

12/10/1967

The GASBUGGY nuclear test was conducted in the San Juan Basin, 55 miles east of Farmington, New Mexico. The device was placed at a depth of 

4,240 ft in a shaft drilled in a gas-bearing sandstone formation. The objective of the test was to investigate the feasibility of using nuclear explosives to stimulate a low-permeability gas field. GNOME was the first Plowshare joint government-industry nuclear experiment to test an industrial application. [Ref: https://www.osti.gov/opennet/reports/plowshar.pdf]

1/1/1968 In early January 1968 members of group J-11 were working with Pb-210 at TA-48. During routine monitoring one employee's shoes were found to be contaminated. The homes of several employees were monitored and one was found to be contaminated. The home was decontaminated. Contam. Event 4066 12

2/1/1968 Four days after a Pb-210 spill in February 1968, Pb-210 contamination was detected in the home of an employee, the area was decontaminated. Contam. Event 817 13-142/7/1968 On February 7, 1968 approximately 100 cc of tritium gas was released in Room 4136 Wing 4 of CMR Building. Air Release 4066 362/8/1968 100 cc of tritium gas may have been released from the exhaust system to the environment on February 8, 1968. Air Release 1180 83/1/1968 An employee broke a charcoal trap which contained approximately 100 cc of tritium, which was released into the exhaust system In March of 1968. Air Release 817 13

4/26/1968 At TA-48 some Pb-210 was spilled on the floor and tracked out of the laboratory. The spill was not detected until 4 days later when Pb-210 was detected during routine surveys. One home had spots reading up to 1500 cpm of alpha radiation on the rug. The rug in the home was removed. Contam. Event NA 5

6/4/1968 The sidewalk, driveway, and rug in the home of an employee were contaminated with Pb 210 sometime around June 14, 1968. Contam. Event 4066 10

9/17/1968 There was an air duct fire in Building 3 between the exhaust blower near Room 313 and the main stack at DP West on September 17, 1968. The fire was due to a welding operation. Fire 817 2-3

9/17/1968 On September 17, 1968 there was a fire in Building 3 main exhaust duct of DP West. No contamination was detected on the roof or duct work. Fire 4066 2

1/2/1969 On January 2, 1969 a contamination accident occurred in Room 606 DP West resulting in the release of plutonium dust. Contam. Event NA 6-7

1/15/1969 A glovebox explosion occurred in the uranium recovery operation at DP West, during the incineration of U-235 metal turnings. Explosion NA 31/15/1969 During the removal of Pu-239 contaminated waste materials from a glovebox line at DP West, the transfer bag ruptured. Explosion NA 32/27/1969 On February 27, 1969 a fire occurred in the #2 glovebox line in Room 500 DP West, resulting in the release of plutonium dust contamination. Fire NA 6-7

3/3/1969 On March 3, 1969 a fire occurred in the leaching hood in Room 313 DP West, during leaching of U-235 contaminated filter frames. Fire NA 6-7

3/25/1969 On March 25, 1969 an explosion occurred in the glovebox of Room 313 DP West. The explosion blew out U-235 dust contamination into the Room. Explosion NA 6-76/26/1969 On June 26, 1969 an explosion occurred in the rag incinerator box in Room 313 DP West during the burning of U-235 turnings. The explosion scattered contamination through out the room. Explosion NA 5

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-30
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 29 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

8/21/1969 On August 21, 1969 approximately 5.73 liters of tritium gas was released into the atmosphere at TA-33. Air Release 4067 410/1/1969 "High levels" of airborne plutonium were detected in the room when a CMF-5 employee dropped a plutonium containing sample. User Error 4182 3,4

10/14/1969 On October 14, 1969 plutonium dust was released from a trash bag during the transfer from a glovebox in Room 308 DP West. Air Release 4182 310/14/1969

On October 14, 1969 a contamination incident occurred in Room 308 DP West, resulting in the release of plutonium dust contamination. The incident 

occurred during the transfer of trash from a glove box in a plastic bag. The bag ruptured resulting in the contamination of the floor. A CMF-5 staff member accidentally dropped a container with plutonium inside. The lid of the container cam off resulting in a high level of airborne Pu contamination.

Air Release NA 4-5

1/16/1970 On January 16, 1970 ZIA craftsmen pumped a caustic solution into the negative water pressure circulating tank in the Building 150 stairwell DP West. Highly contaminated foam escaped through a vent pipe, contaminating the tank, grill, west wall, and stairwell. Liquid Release NA 7

4/3/1970 On April 3, 1970 a furnace containing uranium exploded releasing dust in SM-35 Room 104. Explosion 4261 1

6/10/1970 On June 10, 1970 a tri-state tractor trailer was found to be contaminated with Co60. The trailer was decontaminated, but the source of the contamination is a mystery. Contam. Event NA 4

7/1/1970 A minor fire occurred in the hood of a rag incinerator in Building 3 of TA-21 which was associated with recovery of U-235 oxide. Fire NA 47/1/1970 On May 1, 1970 a ruptured exhaust filter allowed for an increase in air activity. The filter was replaced and no background contamination was found outside of SM-35. Air Release NA 4

9/17/1970 On September 17, 1970 a fire started in a dust collection jar of a vacuum in Room 104 of TA-3-35. The fire started as a result of a spark during the cutting of U-235 fuel elements. Fire NA 9

10/7/1970

On October 7, 1970 a capillary tube containing 238PuO2 broke in an open-faced hood in Room 605a of Building 150 of DP West. The hood exhausted 

directly to the roof without filtration. The room under the stack was contaminated in an area of approximately 100 square feet. Areas of contamination were found on the roof of the office trailer parked northwest of Building 150. No other contamination was found. The areas were decontaminated.

Air Release 4068 6

10/7/1970 A sample of radioactive tritiated salt was lost at Los Alamost Scientific Laboratory. The sample was reported missing 9-29-70 after routine inventory. An exhaustive search failed to turn up the missing sample. User Error NA 120

3/29/1971 On March 29, 1971 a worker was emptying a dempster dumpster in pit 6, area G, TA 54 when a strong gust of wind blew contamination onto the truck and the container. Air Release 3972 106

3/29/1971 On March 29, 1971 Pu238 became airborne during the unloading of a dumpster containing radioactive waste at the disposal pit. The truck carrying the waste was contaminated and the contamination did not escape the disposal pit. Air Release 4705 4

3/29/1971 On March 29, 1971 during the emptying of a dumpster of radioactive waste at TA-54 Pu-238 became airborne and contaminated the truck carrying the dumpster. The decontamination did not escape the disposal pit. Air Release NA 5

7/31/1971 On July 31, 1971 Pu 238 was released during the disassembly of a transit heat source containing 26,092 Ci of plutonium. Some contamination was released into Wing 9 of CMR Building. 55 microcuries escaped the building over a period of 16.5 hours. Air Release 3972 5

7/31/1971 On July 31, 1971 employees were working with a capsule containing Pu-238 in Room 9130, Wing 9, CMR Building. Contamination was released into the room and the workers were contaminated. Contam. Event 5442 1

10/7/1971 On October 7, 1971 a release of Pu-238 oxide occurred in 605 DP West contaminating 200 sq ft of the building, the roof and the surrounding ground. Contam. Event NA 6

10/15/1971 There was a fire in exhaust filter SM-102 on October 15, 1971. Fire 1417 3

11/2/1971 On November 2, 1971 an explosion in test cell furnace blew uranium contamination onto floor. Explosion 1417 3

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-31
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 30 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

12/17/1971 On December 17, 1971 high Pu-238 air counts were detected due to contamination from an exploding bottle. Explosion 1417 3

8/1/1973 XO-2 cooling loop leaks at TA-53 allowed 1.5 Ci of tritium to be transferred along with 25,000 L of waste water from the waste tanks in the experimental area to the sewage lagoons at TA-53 between July 1, 1978 and September 30, 1978. Air Release NA 32

7/9/1974 On July 9, 1974 it was discovered that a pipe conveying radioactive wastes to TA-50 was leaking north of Pajarito road east of TA-3-184. The section of pipe was repaired. Liquid Release 515 6

8/14/1975 On Aug. 14 approximately 10 gallons of reactor water went down the drain to the dry creek bed. Liquid Release 392a 168/27/1975

On Aug. 27, 1975 approximately 960 gallons of regenerate material spilled out of a sludge holding tank contaminating Room 60A, TA-50. Approximately 500-700 gallons was lost outside. The solution contained Cs, Pu, St, Am. The spill area was roped off, covered with wet sand to minimize airborne contamination, and cleaned.

Liquid Release 392a 15

1/1/1976 In 1976 approximately 3271 Ci of tritium was release into the environment (this does not include 22,000 Ci released from TA-3-34 on July 15, 1976). Air Release NA 13

7/15/1976 On July 15, 1976 there was a tritium release from TA-3-34 of 22,000 Ci. Air Release NA 15

1/1/1977 In 1977 approximately 6417 Ci of tritium was released into the environment (this does not include 30,800 Ci released from TA-33-36 on October 6, 1977). Air Release NA 13

10/6/1977 On October 6, 1977, 3.08 x1010 μCi of tritium gas was released from Room 9 TA-33-86 due to a loose high pressure fitting. Averaged over 24 hours 

the stack concentration was 0.104 uCi/ml.

Air Release 1232 5

10/6/1977 On October 6 1977 there was a tritium release from TA-33-86 of 33,217 Ci. Air Release NA 1810/6/1977 On October 6, 1977 there was a tritium release of 30,800 Ci from TA-33-86. Air Release NA 15

11/11/1977 On November 11, 1977, at TA-54 Burial Pit seven bales of suspect low-level radioactive contaminated combustible waste auto-ignited. Apparent cause was a bottle, or bottles of acid improperly disposed of in the combustible waste. Fire NA 22

8/22/1978 On August 22, 1978 SM-102 a drum of depleted U-238 chips ignited while being moved to the outside. Fire NA 18

10/30/1978 It was discovered on October 30, 1978 that a large amount of tritium was released when a glass ballast valve was left open. Air Release 3462 3

12/1/1978 An LASL employee contaminated the sleeve of his shirt, which was not detected until the employee returned to work following day. No contamination was detected at his home or in his automobile. User Error NA 10

5/4/1979 On May 4, 1979 approximately 3000 Ci of tritium was released from SM-34. Air Release 3462 1025/4/1979 A stainless steel pot containing uranium tritide was overheated in a laboratory at the Cryogenics Building and ruptured on May 4, 1979. tritiated water escaped into the laboratory because of inadequate air flow in the hood. Some tritium was released to the atmosphere. Liquid Release 4484 1-25/4/1979 On May 4, 1979 there was a tritium release of ~3,000 Ci from TA-3-34. Air Release NA 185/7/1979 Tritium exposure incident at SM-34 on May 4, 1979. Contam. Event NA 4

5/18/1979

On May 18, 1979 during the transfer of 1500 gallons of contaminated water from the north holding tank to LAMPF Site sewage lagoons. The area A parking lot and area A shop floor were flooded, procedures to prevent the spread of contamination were used and the areas were quickly decontaminated.

Liquid Release 4154 91

5/25/1979 On May 25, 1979 approximately 3000 Ci of tritium were released from SM-34. Air Release 4154 948/22/1979 On August 22, 1979 approximately 200 grams of UF6 was released at Building 23 TA-18 Pajarito Site. Approximately 0.0038 grams was released into the environment. The majority of the ~200 grams (~180 grams) was caught in the HEPA filter. Air Release 4154 20

9/17/1979 A dempster dumpster fire occurred at TA-33-86 on September 17, 1979. The only radioactive isotope believed to be present at the time of the fire was tritium. Fire 4154 6

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-32
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 31 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

12/12/1979 On December 12, 1979 150 to 200 gallons of slightly radioactive primary reactor system water was released at TA-2 inside Building 44. Approximately 50 gallons drained to a nearby creek via a floor drain in Building 44. Liquid Release 4154 1

11/1/1980 In November 1980 there was a release of 16 curies of tritium gas and a total of 10 minor radiation releases of plutonium in labs reported internally. Air Release 933 19

2/1/1981 In February 1981 a total of 11 minor radiation accidents were reported internally. Contam. Event 936 17

3/19/1981 On March 19, 1981 liquid from an industrial waste line serving TA-48 was inadvertently pumped into Mortandad canyon. Liquid Release NA 128-129

3/24/1981 On March 24, 1981 several curies of gaseous tritium were released from the Van de Graaff Building at TA-3. Air Release NA 128-129

10/14/1981

On October 14, 1981 ten samples contaminated with PuO2 were opened in a laboratory where Pu is not normally handled. Contamination was spread 

into several laboratories, a small shop, the analyst and several other workers before it was detected. One vehicle and two homes were contaminated with a small amount of material. All employees and contaminated areas were readily decontaminated.

Contam. Event 2057 8

10/14/1981 plutonium contamination incident at TA-3, SM-29, October 14, 1981. Contam. Event NA 35

11/1/1981 In November 1981 ten minor radiation releases were documented and investigated internally at LANL. Contam. Event 935 203/19/1982

On March 19, 1982 a section of the industrial waste line carrying fission products from hot cells serving TA-48 had been found leaking. A limited area of soil was contaminated within Laboratory boundaries. The affected soil from the areas along both sides of the road behind TA-48 were removed (down to bedrock) up to the edge of Mortandad Canyon, and replaced with clean soil.

Liquid Release 4412 1

8/10/1982 On August 10, 1982 a furnace at TA-55 ignited and over pressurized a glovebox. Two glovebox windows ruptured releasing alpha contamination into the room and adjacent corridor. Air Release NA 611/2/1982 On November 2, 1982 approximately 50-100 liters of waste liquid escaped from a tank vent at TA-21-257 contaminating the building roof, walls, and surrounding area with low levels of plutonium, americurium, and uranium. Liquid Release NA 6

1/10/1983 An accidental release of chromium oxychloride occurred at the Van de Graaff facility on January 10, 1983. The accident occurred when an employee removed a valve from one end of a pipe which allowed for the liquid stored in the pipe to spill on the floor. Liquid Release NA 4

6/1/1983 On June 1, 1983 high airborne plutonium levels were detected in Room 429 at TA-55 Building PF-4. The high levels were caused by a leak in the dry vacuum line to a glovebox. Air Release NA 1

6/1/1983 Radiation material was discovered in the salvage yard and reported during the report period. Contam. Event NA 4

8/25/1983 On August 25, 1983 a puff release of 104 Ci of tritium occurred at TA-33. This was followed by a slow release of an additional 45 Ci in the subsequent 24 hour period. Air Release NA 4

11/28/1983

On November 28, 1983 a fire occurred in the well house at Pajarito water supply well no. 2. Two large PCB capacitors were involved in the fire 

emitting PCB when the heat caused them to rupture releasing their contents. Air and ash samples confirmed significant PCB contamination inside the building.

Fire NA 3-4

12/6/1983 On December 6, 1983 two plutonium containing shipping containers were inadvertently opened, contaminating the clothing and skin of eight workers. Contam. Event NA 3-42/17/1984 Fire at TA-50 Building 1 in a ventilation exhaust plenum on February 17, 1984, filter bags were ignited. Fire NA 64/10/1984 Hydrogen fluoride release on April 10, 1984 from Room 5096 at TA-3-29 through a hole in an exhaust flex hose of the gas centrifuge. Air Release NA 4-5

7/1/1984 There was a fire at the lithium hydride shop TA-3, SM-39 on June 6, 1984. Lithium hydride dust ignited in a section of exhaust duct. Fire NA 4-5

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-33
Table 16-1. Partial Chronology of Accidents, Incidents, and Important Events at LANL Page 32 of 32

Date of 

Incident Description Incident Type Repos. No. Initial Page of Interest

7/26/1984 Equipment failure to contain plutonium solution resulting in significant area contamination and high nose swipes for three employees on July 26, 1984 at TA-55-4-401. Equipment Malfunction NA 2-3

10/19/1984 Inadequate procedures when handling packaged Pu-238 resulted in widespread area contamination and contamination of personal clothing of two employees on October 19, 1984 at TA-54. Contam. Event NA 2-3

1/11/1985 On January 1, 1985 a failure to comply with established procedures resulted in a release of radioactive materials along a public roadway (report no. LAMPF-85-1). Contam. Event NA 6

6/1/1985 60 gallons of tri-methyl benzene were spilled in the neutrino area at the L.A. Meson Physics Facility, no serious injuries resulted form this accident. Liquid Release NA 6

6/12/1985 On June 12, 1985 the improper transfer of radioactive material resulted in an employee's home being contaminated (Report no. AHP-85-8). Contam. Event NA 6

7/1/1985 On July 1, 1985 activated cooling water was discharged outside facility (Report no. LAMPF-85-5). Liquid Release NA 6

9/12/1985 On September 12, 1985 there was a fire in a glove box at TA-55-4-429 which resulted in high airborne activity and area contamination (Report no. CHEM-HP-85-20). Fire NA 6

2/2/1986 On February 2, 1986 there was an unexpected release of tritium oxide at TA-41-4-236A. Air Release NA 11

10/30/1986 On October 30-31, 1986 an estimated 633 Ci of tritium were released at TA-33, mostly in the form of tritiated water. Air Release NA 8

11/14/1986 On November 14, 1986 11.5 Ci of tritium was released from TA-33 in the form of elemental tritium. Air Release NA 8

11/1/1987 Low level liquid waste from TA-55 showed higher than normal levels of plutonium in Nov. and Dec. There was a pinhole leak in a stream coil in a cascade dissolver process at TA-55 Liquid Release NA 4

2/22/1988 On Feb 22, approximately 5800 Ci of tritium were released from TA-33. Air Release 1246 82/27/1990 On February 27, 1990 cooling water overflowed in the exhaust system of TA-55-4. Liquid Release NA 8

3/1/2000 An incident occurred in March 2000 when eight workers at TA-55 were exposed to airborne plutonium. Air Release NA 13/1/2000 An incident occurred in 1998 when a worker at TA-55 was exposed to airborne plutonium. Air Release NA 15/4/2000 On May 4, 2000 a wild fire was ignited which ulitmately burned nearly 50,000 acres in and around Los Alamos New Mexico. Fire NA 1

7/27/2005 A small amount of americium-241 was found to have contaminated a package that was shipped from Los Alamos to Pennsylvania. The contamination was spread to homes in Colorado, Kansas, and New Mexico. Contam. Event 6204 all

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 16 Page 16-34
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-1 

Chapter 17: Prioritization of Radionuclide Releases 

The LAHDA team identified the following steps to be completed to prioritize radionuclide releases: 

1) Review the history of operations at Los Alamos, 

2) Find relevant data concerning air and liquid releases, 

3) Correct or adjust older data with appropriate factors based on current state-of-the-art methods, 

4) Fill in gaps in data with justifiable methods for estimation of air and liquid releases, and 

5) Prepare a prioritized list of radionuclides for both operational and episodic releases. 

The prioritization of historical releases focused on providing a relative ranking of radionuclide releases 

that may have impacted public health and to limit attention to radionuclides that did not impact human 

health. Prioritization to date has been accomplished using a method based on the volume of air or water 

required to dilute the radionuclide in question down to maximum effluent concentrations for public 

areas− this is defined to be “Priority Index”. This simple method does not require the definition of a 

specific “receptor” nor does it require use of an exposure pathway model. For certain historical releases, 

namely airborne plutonium from DP West Site, it was determined that more developed evaluation based 

on the screening methods of National Council on Radiation Protection and Measurements (NCRP) Report 

No. 123 should be used (NCRP 1996). That screening evaluation is described in Chapter 18. 

Priority Indices were calculated based on estimated quantities released and maximum effluent 

concentrations documented in Title 10 of the Code of Federal regulations, Part 20 (USNRC 2003). They 

are intended to be guidelines to determine the relative rank of a release in comparison with others. The 

prioritization methods described herein require that some estimates of quantities of each radionuclide or 

radionuclide class released to the environment be available. In some cases, these data are not available 

for all facilities or for all years of operations at Los Alamos. 

The prioritization of releases from LANL has been problematic. During the Manhattan Project era and 

continuing well into the post-1946 AEC era, LASL did not measure many of their release points and did 

not systematically archive and compile effluent data. No effort has been made to characterize the 

magnitude of the releases from non-point source emissions that have been shown to be particularly 

important at other DOE sites such as Rocky Flats. Unlike most DOE sites, LANL’s compilations contain 

well-documented effluent data for only the post Clean Air Act (post-1969) era. Only summary-level 

information for certain facilities is given in LANL’s compilations prior to this period. In addition, 

potentially important release sources such as D Building (Fig. 17-1), which housed processing of 

plutonium during World War II and remained active until around 1953, were not subjected to stack 

sampling programs and have no effluent data available. 
 17-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17

Unlike any other AEC/DOE site studied thus far with regard to historical releases, there was nothing 

approaching a comprehensive compilation of releases available at LANL to establish a simple, initial 

prioritization. The best available compilation was one assembled in the early 1970s to support 

preparation of the first site-wide final environmental impact statement (FEIS) that LANL published in 

response to the requirements of the Clean Air Act (USDOE 1979). The LAHDRA team has found that 

compilation to have numerous errors and omissions. Despite these errors and omissions, the preliminary 

prioritization used data assembled for that report as well as other information, such as estimates of the 

quantities of uranium expended in explosive test shots, to augment the LANL compilation. 

Prioritization of Airborne Radionuclide Releases 

LANL operations started in 1943 and have continued to the present. In the early years, radiation science, 

environmental science, and occupational health were all disciplines that were in their infancy. As time 

progressed, LANL has, by their own volition and by pressure from the public and government, increased 

monitoring, documentation, and reporting. 

Data Sources 

There are six main data sources for the airborne radionuclide effluent information at LANL: 

• (Andrews ca. 1973) – “Joe Graf Binders” 1 and 2– Two binders of documents assembled by LANL 

Environment, Safety, and Health (ES&H) staff for group leader Joe Graf in the early 1970s that 

document releases from LANL before 1973. This was done to support development of a draft 

Fig. 17-1. The earliest plutonium processing at Los Alamos was conducted in this facility, known as 

D Building. Airborne effluents through approximately 85 rooftop vents were unmonitored and largely 

unfiltered. Photograph from the late 1940s. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-3 

site-wide Final Environmental Impact Statement (FEIS). The FEIS was finally published in 1979. 

The documents assembled in these binders include records of room air concentrations, stack 

monitoring data, ES&H reports, and miscellaneous memos. 

• (Miller 2001) - Scott Miller, also an ES&H group member, compiled stack release data from 1973 to 

1990. These data were assembled in a three-ring binder that was shared with the LAHDRA team and 

entered into the LAHDRA project information database. A Microsoft Excel® spreadsheet file 

containing the associated data was also provided to the project team. 

• (Dummer et al. 1996) – A detailed study of all the RaLa shots conducted in Bayo Canyon at Los 

Alamos and the quantities of RaLa involved in those explosives tests from 1944 to 1962. 

• (Drake and Eyster 1971) – A memo that details estimated quantities of uranium that were expended in 

explosive testing at LANL from 1944 to 1970. 

• (Jordan and Black 1958) – An article in the American Industrial Hygiene Association Journal that 

speaks of airborne radioactive effluents from LANL). This work is one of the most important early 

studies on releases. LANL has considered the Jordan and Black publication to be the best-available 

scientific data identified on possible early emissions. As discussed later in this chapter, the LAHDRA 

project team disagrees with that assessment. 

• (Hyatt 1956) – A 1956 memorandum prepared by an alternate group leader of the LASL industrial 

hygiene group that documents results of a 1955-1956 study that yielded corrected plutonium release 

estimates for DP West Building 12 stacks on a monthly basis for 1948 through 1955. 

Summary of Results for Prioritization of Airborne Radionuclide Releases 

During the period of LANL’s existence, many operations involving radionuclides have been performed, 

and effluents containing various radioactive constituents have been released. This section outlines the 

calculation of priority indices for six airborne radionuclide sets (plutonium, uranium, tritium, Radioactive 

Lanthanum (RaLa), Mixed Fission Products (MFP), and Mixed Activation Products (MAP)) for off-site 

airborne releases from LANL. 

A Priority Index (PI) (in units of liters, L) for airborne radionuclide releases is calculated by computing 

the air volume required to dilute the annual activity released to be equal to the worst-case maximum 

effluent concentration per 10 CFR 20 (USNRC 2003). This priority index is intended to be a guideline to 

determine if a nuclide set requires further iterations of calculation and refinement, or if it warrants lower 

priority relative to other nuclides (O'Brien J. and Burmeister R. 2004). For example, a PI of 106

 L 

indicates that 106 (or one million) liters of air would be required to dilute the released material to a 
 17-4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17

concentration equal to the maximum effluent concentration. The priority index does not consider 

environmental transport and dilution. Although the lowest available (most conservative) maximum 

effluent concentration is used, the priority index does not otherwise address uptake factors. It does not 

consider decay in transport, which means the priority index would tend to overstate the importance of 

short-lived materials. Within these limitations, it provides a simple tool for establishing the relative 

importance of various airborne releases. 

For the years 1944 to the present, LANL summary data were reviewed to collect available information for 

air releases and inventories used in explosions. This effort did not include an independent source term 

reconstruction; rather it relied on LANL compilations of releases with some adjustments by the LAHDRA 

team. Not all the data compiled herein are measurements of stack releases. A Microsoft Access®

Off-Site Releases (OSR) Database was created to tabulate the available information and to link it to 

existing LANL documents that have been located and assembled by the LAHDRA project team. In most 

cases, these documents are available as image files in Adobe Acrobat® Portable Document Format (PDF) 

files that are linked to records containing bibliographic information the LAHDRA DocSleuth database. 

Radionuclide “Sets” and “Collections”

The summary data for airborne radionuclide prioritization is grouped by radionuclide “collections” or 

“nuclide sets” because of the conventions used by LANL staff in quantifying and reporting concentrations 

and releases. These “sets” are as follows: plutonium, uranium, tritium, Radioactive Lanthanum (RaLa), 

Mixed Fission Products (MFP), and Mixed Activation Products (MAP). Certain collections of nuclides 

are grouped in LANL documents. For instance, in many cases, effluent data reports have the 

radionuclides 239Pu, 238Pu and 235U associated. In some cases no mention of the analysis type is made, and 

so the analysis result can be attributed to several nuclides. In these cases, the nuclide collection would 

have all of these radionuclides listed in it as a string. During the analysis, when separating the nuclides, 

“nuclide sets” were created that are simply the nuclide collection values that will be attributed to a nuclide 

such as plutonium. Plutonium has the lowest value for maximum effluent concentration, so if a nuclide 

collection contained both plutonium and uranium, then the value was counted for plutonium. This 

method was used to prevent both “double counting” the release and to assign the larger value to 

plutonium. This practice may overstate the importance of plutonium, particularly after the late 1970s. 

When the “nuclide set” was created for uranium, only those entries that did not contain plutonium 

isotopes were included. 

Effluent Data for Plutonium: Plutonium data were obtained for calendar years from 1948 through 1996. 

Release estimates are not available for D Building. D Building started operation in late 1943/early 1944, 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-5 

and continued to be used until around 1953. It is important to note that no airborne effluent data were 

included in LANL compilations for the years 1944 through 1947. In addition, the releases from DP Site 

reported by LANL for 1948, 1949, and 1950 are apparently based on simple estimates first made by 

Jordan and Black using methods that are not well documented (Jordan and Black 1958). 

Airborne plutonium releases were prioritized based on values compiled for the 1979 FEIS and also 

documented in a 1975 publication (Maraman et al. 1975). Values for 1948–1955 were adjusted upward 

by the LAHDRA team (by roughly a factor of 20) to agree with results of a study conducted by the LANL 

industrial hygiene group in 1955 and 1956 and reported by Edwin C. Hyatt in 1956 (Hyatt 1956). In that 

study, stack concentrations were measured with improved, isokinetic stack sampling systems that were 

operated alongside the original systems (Hyatt 1955). After six months of sampling, results were 

compared and correction factors were determined and applied to releases previously reported for 1948-

1955. Past that point, the improved sampling system was used. 

All values from 1948 through 1975 were adjusted upward further by the LAHDRA team using a sample 

line loss correction factor equal to 5 for 1945-1958 and 2 for 1959-1975 based on analyses performed by 

LANL staff (Fuehne 2008). The reduction of the line loss correction factor starting with 1959 is in 

consideration of the fact that a single stage of high efficiency particulate air (HEPA) filters was added to 

the combined process exhaust system at DP West in 1959 (Maraman et al. 1975), and the particle size 

distribution in that exhaust stream likely shifted toward smaller particles. A filter burial correction factor 

of 2.33 was also applied to plutonium release totals reported by LANL for 1948 through 1975 based on 

assessments performed by LANL staff (Fuehne 2008). These line loss and filter burial corrections might 

also be appropriate for years following 1975, but have not been applied in this calculation. No 

documentation has been found identifying when LANL first applied these correction factors, but routine 

application is evident by the 1980s. 

The maximum effluent concentration used for calculation of priority indices for plutonium releases was 

2.0×10-14 μCi mL-1 from 10CFR20 Appendix B, Table 2. Table 17-1 presents the estimated annual 

release totals (μCi) and priority indices (dilution volume, L) for plutonium. The priority indices for 

plutonium over the years of LANL operations range in magnitude from 1011 to 1018. 

Uranium Effluent Data: The uranium data found range from 1949 to 1996. Some of these data are 

uranium inventory data from uses in experiments involving explosive testing and some data are from 

stack monitoring. In the case where a nuclide collection contained both plutonium and uranium, it was 

counted in the plutonium data. The uranium data are for nuclide collections that contain only uranium. 

For the explosion data, the mass was multiplied times a specific activity for the nuclide group (for 
 17-6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17

example, depleted uranium or natural uranium). Uranium data from stack sampling also had the sample 

line loss and filter burial correction factors applied to all data prior to 1976, in the same manner as 

described for plutonium releases (Fuehne 2008). 

Atmospheric Release Fractions (ARF) and Respirable Factions (RF) (USDOE 1994) were multiplied to 

get a range of Overall Release Fractions (ORF). The ORF-corrected values represent the amount of the 

radionuclide that got into the air and contains respirable-size particles. The geometric mean of the ORF, 

estimated as the square root of the range of values, is 0.001. This value was applied to the entire uranium 

inventory documented as expended in explosive tests. 

The maximum effluent concentration used for calculation of priority indices for uranium releases was 

6.0×10-14 μCi mL-1 for 235U from 10CFR20 Appendix B, Table 2. Table 17-2 presents estimates of annual 

release quantities and priority indices for uranium. The overall range for the priority indices was from 

approximately 1011 to approximately 1017. In general, in the post-1973 era, the uranium priority indices 

appear to indicate greater significance than plutonium. In the pre-1973 era, plutonium was of greater 

significance. It is noteworthy that the years 1967, 1968, and 1969 have very high uranium release values. 

These values are directly from the LANL documents (see Fig. 17-2 below). During the LAHDRA project 

it was not possible to confirm if these values were actually quantities released, or whether they might 

represent quantities expended in explosive testing. It is possible that quantities expended were 

documented without consideration of fractions that were aerosolized. 

Fig. 17-2. Unusually high uranium values (in curies) documented by LASL (Andrews ca. 1973)

Tritium: Effluent data obtained for tritium range from 1967 to 1996, even though tritium was used at Los 

Alamos as far back as 1945 or possibly 1944. No correction factors were applied to tritium data. The 

maximum effluent concentration used for calculation of priority indices for tritium releases was 1.0×10-7

μCi mL-1 from 10CFR20 Appendix B, Table 2. Table 17-3 presents estimated annual release quantities 

and priority indices for tritium. The priority indices for tritium range from 1012 to 1014. In the post-1973 

era, tritium appears to have been more significant than uranium or plutonium, but less significant than 

MAP. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-7 

Tritium has a relatively short half-life (approximately 12.3 y compared to plutonium and uranium at 

thousands of years) and it is readily incorporated into compounds. More data are required for pre-1967 

tritium releases at LANL. LAHDRA staff have found and added to the project information database 

additional documents containing tritium release data associated with episodic releases before and after 

1967, but these data are scattered across many documents and have not yet been compiled or used to 

bound releases before 1967. 

Radioactive Lanthanum (RaLa): The RaLa testing program at Los Alamos was the subject of a dose 

reconstruction by LANL personnel, including a source term evaluation (Dummer et al. 1996). All of the 

RaLa release data obtained by the LAHDRA team are from explosive tests from 1944 to 1962, with no 

shots conducted during 1951. No correction factors were applied to the activity data by the LAHDRA 

team. Since it was desired to estimate the actual RaLa releases to air, the same ORF used for uranium 

(0.001) was applied to RaLa source strength data for each shot. 

The maximum effluent concentration used for calculation of priority indices for RaLa releases was 

2.0×10-9 μCi mL-1 for 140La from 10CFR20 Appendix B, Table 2. Table 17-4 presents annual estimates of 

quantities released and priority indices for the RaLa tests. The priority indices ranged from 1011 to 1013. 

While a detailed evaluation of LANL’s dose assessment for RaLa releases has not been performed, it 

appears from this preliminary assessment that RaLa does not warrant high priority in assessments of 

airborne radionuclide releases. 

Mixed Fission Products (MFP): MFP data reported by LANL begin in 1961 and continue through 1996. 

Their variability is quite high. The reasons for this variability and the lack of data prior to 1961 have not 

yet been explored. It is believed that the main source of MFP radionuclides was the Omega reactor. For 

some years– for example 1969, 1972, 1973, and 1994– the reported MFP activity released was much 

higher than in other years. The reasons for these elevated values have not yet been explored. 

The maximum effluent concentration used for MFP was 1.0×10-7 from Footnote 2 to the radionuclide 

tables in Appendix B to 10CFR20. Table 17-5 presents estimated annual release quantities and priority 

indices for MPF releases. The priority indices for MFP are not high in relative terms; they range in 

magnitude from 106

 to 1012. If the correction for decay during environmental transport were applied, they 

would be even lower, since MFP radionuclides in general have short half-lives. 

Mixed Activation Products (MAP): MAP make up the largest portion of the airborne radioactive releases 

after 1973. Reactors and large accelerators are the main producers of MAP radionuclides. At Los 

Alamos, this would mean the majority of the MAP would come from TA-53 and the Los Alamos Meson 

Physics Facility (LAMPF), now called the Los Alamos Neutron Science Center (LANSCE). Although 
 17-8 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17

LAMPF started operations in 1971, no pre-1976 effluent data were found for MAP. Based on the 

conventions used by LANL to report activation product releases, the nuclides included in the MAP 

“nuclide set” were as follows: 

• “MAP”, 

• Gaseous Mixed Activation Products (“G/MAP”), 

• Particulate Various Activation Products (“P/VAP”), and 

• Air activation products C-11, N-13, O-15, and Ar-41. 

These are all short-lived MAP radionuclides that accelerator Health Physicists traditionally consider to be 

“MAP.” However, this facility also releases activation products that are longer-lived particulates. These 

particulate releases are traditionally not considered “MAP”. Short-lived MAP is measured via an in-stack 

ion chamber, whereas the particulates are long-lived and measured by counting of in-stack filters in a 

laboratory. 

The maximum effluent concentration used for prioritization of MAP releases was a value of 2.0×10-7 μCi 

mL-1 published by the International Atomic Energy Agency (IAEA 1979). Table 17-6 presents estimates 

of annual release quantities and priority indices for MAP releases. Priority indices varied in magnitude 

from 108

 to 1015. In 1990, the priority index was smaller than in other years. Examination of the 

available data indicated that for 1991 there are five records with data relevant to the MAP “nuclide set,” 

but for 1990, there are only two records. This paucity of reported data, with possibly some data missing, 

resulted in the lower priority index for 1990. No further investigation has yet been possible. 

Fig. 17-3 presents a combined plot of annual priority index values for airborne radionuclide releases from 

LANL facilities, and Table 17-7 presents a summary of the classes of radionuclides with highest priority 

indices for each period of LANL operations. 
Year Release, μCi Priority Index, L

1948 1.31E+07 6.57E+17

1949 6.36E+07 3.18E+18

1950 4.53E+07 2.27E+18

1951 7.66E+06 3.83E+17

1952 1.23E+07 6.13E+17

1953 6.17E+06 3.09E+17

1954 3.68E+06 1.84E+17

1955 1.45E+07 7.27E+17

1956 9.03E+05 4.51E+16

1957 8.74E+05 4.37E+16

1958 9.68E+05 4.84E+16

1959 2.18E+06 1.09E+17

1960 4.44E+05 2.22E+16

1961 9.50E+04 4.75E+15

1962 1.14E+05 5.70E+15

1963 8.12E+04 4.06E+15

1964 3.36E+04 1.68E+15

1965 1.27E+05 6.35E+15

1966 1.43E+05 7.17E+15

1967 3.75E+05 1.87E+16

1968 3.55E+05 1.77E+16

1969 5.13E+05 2.57E+16

1970 1.49E+05 7.46E+15

1971 7.43E+04 3.71E+15

1972 9.76E+04 4.88E+15

1973 1.01E+05 5.04E+15

1974 9.90E+03 4.95E+14

1975 2.90E+03 1.45E+14

1976 6.79E+01 3.40E+12

1977 1.27E+02 6.35E+12

1978 1.12E+02 5.60E+12

1979 1.09E+03 5.45E+13

1980 7.47E+02 3.74E+13

1981 5.65E+01 2.83E+12

1982 1.12E+02 5.60E+12

1983 1.13E+02 5.65E+12

1984 1.41E+02 7.05E+12

1985 2.13E+02 1.07E+13

1986 2.07E+02 1.04E+13

1987 7.28E+01 3.64E+12

1988 7.23E+01 3.62E+12

1989 4.53E+01 2.27E+12

1990 2.57E+01 1.29E+12

1991 3.55E+01 1.78E+12

1992 1.91E+01 9.55E+11

1993 6.44E+00 3.22E+11

1994 1.25E+01 6.25E+11

1995 8.90E+01 4.45E+12

1996 2.33E+01 1.17E+12

a

 Note regarding scientific notation: 4.96E+05 equals 4.96×10+5, 

which equals 4.96×100,000 or 496,000. 

Table 17-1: Airborne Plutonium Release Estimates and Priority Indices a

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 17 17-9
Year Release, μCi Priority Index, L

1948

1949 1.88E+03 3.13E+13

1950 1.95E+04 3.25E+14

1951 4.54E+03 7.56E+13

1952 4.04E+03 6.74E+13

1953 2.80E+02 4.66E+12

1954 4.61E+03 7.69E+13

1955 6.80E+03 1.13E+14

1956 1.20E+04 1.99E+14

1957 3.67E+03 6.11E+13

1958 3.01E+03 5.01E+13

1959 5.00E+03 8.33E+13

1960 2.52E+03 4.20E+13

1961 2.99E+03 4.98E+13

1962 3.03E+04 5.05E+14

1963 8.88E+04 1.48E+15

1964 1.61E+04 2.69E+14

1965 2.36E+04 3.93E+14

1966 2.38E+04 3.97E+14

1967 2.23E+07 3.72E+17

1968 1.46E+07 2.44E+17

1969 1.50E+07 2.50E+17

1970 2.52E+04 4.20E+14

1971 1.29E+05 2.14E+15

1972 3.66E+04 6.09E+14

1973 1.75E+04 2.92E+14

1974 9.37E+03 1.56E+14

1975 1.07E+04 1.78E+14

1976 1.35E+03 2.24E+13

1977 7.09E+02 1.18E+13

1978 5.27E+02 8.78E+12

1979 9.33E+02 1.55E+13

1980 7.91E+02 1.32E+13

1981 1.27E+03 2.12E+13

1982 1.37E+03 2.29E+13

1983 8.88E+02 1.48E+13

1984 1.21E+03 2.01E+13

1985 7.28E+02 1.21E+13

1986 8.44E+02 1.41E+13

1987 1.08E+03 1.79E+13

1988 5.59E+02 9.31E+12

1989 3.94E+02 6.56E+12

1990 3.49E+03 5.82E+13

1991 7.92E+04 1.32E+15

1992 2.60E+03 4.33E+13

1993 5.09E+03 8.48E+13

1994 3.88E+02 6.47E+12

1995 5.27E+03 8.78E+13

1996 3.90E+01 6.50E+11

a

 Note regarding scientific notation: 4.96E+05 equals 4.96×10+5, 

which equals 4.96×100,000 or 496,000. 

Table 17-2: Airborne Uranium Release Estimates and Priority Indices a

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 17 17-10
Year Release, μCi Priority Index, L

1948

1949

1950

1951

1952

1953

1954

1955

1956

1957

1958

1959

1960

1961

1962

1963

1964

1965

1966

1967 2.79E+10 2.79E+14

1968 3.17E+10 3.17E+14

1969 3.45E+10 3.45E+14

1970 3.71E+10 3.71E+14

1971 1.02E+10 1.02E+14

1972 6.51E+09 6.51E+13

1973 1.29E+09 1.29E+13

1974 7.32E+09 7.32E+13

1975 6.20E+09 6.20E+13

1976 3.40E+09 3.40E+13

1977 3.86E+10 3.86E+14

1978 1.86E+10 1.86E+14

1979 1.50E+10 1.50E+14

1980 7.52E+09 7.52E+13

1981 7.23E+09 7.23E+13

1982 1.59E+10 1.59E+14

1983 7.89E+09 7.89E+13

1984 1.49E+10 1.49E+14

1985 8.64E+09 8.64E+13

1986 1.07E+10 1.07E+14

1987 3.17E+09 3.17E+13

1988 1.10E+10 1.10E+14

1989 1.44E+10 1.44E+14

1990 1.18E+10 1.18E+14

1991 5.17E+09 5.17E+13

1992 1.30E+09 1.30E+13

1993 1.48E+09 1.48E+13

1994 1.07E+09 1.07E+13

1995 1.11E+09 1.11E+13

1996 5.77E+08 5.77E+12

Table 17-3: Airborne Tritium Release Estimates and Priority Indices a

a

 Note regarding scientific notation: 4.96E+05 equals 4.96×10+5, 

which equals 4.96×100,000 or 496,000. 

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 17 17-11
Year Release, μCi Priority Index, L

1944 1.11E+06 5.55E+11

1945 1.84E+07 9.20E+12

1946 2.06E+07 1.03E+13

1947 2.27E+07 1.14E+13

1948 1.22E+07 6.10E+12

1949 2.83E+07 1.42E+13

1950 1.98E+07 9.90E+12

1951 No shots No shots

1952 6.37E+06 3.19E+12

1953 1.07E+06 5.35E+11

1954 1.56E+07 7.80E+12

1955 4.08E+07 2.04E+13

1956 3.60E+07 1.80E+13

1957 1.74E+07 8.70E+12

1958 9.85E+06 4.93E+12

1959 8.32E+06 4.16E+12

1960 5.56E+06 2.78E+12

1961 2.43E+07 1.22E+13

1962 1.36E+07 6.80E+12

1963

1964

1965

1966

1967

1968

1969

1970

1971

1972

1973

1974

1975

1976

1977

1978

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

Table 17-4: Airborne RaLa Release Estimates and Priority Indices a

a

 Note regarding scientific notation: 4.96E+05 equals 4.96×10+5, 

which equals 4.96×100,000 or 496,000. 

Testing program completed.

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 17 17-12
Year Release, μCi Priority Index, L

1948

1949

1950

1951

1952

1953

1954

1955

1956 9.35E+05 9.35E+09

1957

1958

1959

1960

1961 1.80E+03 1.80E+07

1962 4.31E+05 4.31E+09

1963 6.77E+05 6.77E+09

1964 3.12E+05 3.12E+09

1965 3.84E+05 3.84E+09

1966 3.98E+04 3.98E+08

1967 1.31E+04 1.31E+08

1968 1.35E+04 1.35E+08

1969 1.44E+08 1.44E+12

1970 1.74E+04 1.74E+08

1971 3.75E+04 3.75E+08

1972 7.13E+08 7.13E+12

1973 2.10E+08 2.10E+12

1974 6.11E+03 6.11E+07

1975 2.31E+03 2.31E+07

1976 1.97E+03 1.97E+07

1977 2.85E+03 2.85E+07

1978 1.69E+03 1.69E+07

1979 1.71E+03 1.71E+07

1980 2.29E+03 2.29E+07

1981 1.61E+03 1.61E+07

1982 1.97E+03 1.97E+07

1983 9.26E+02 9.26E+06

1984 1.69E+03 1.69E+07

1985 1.40E+03 1.40E+07

1986 2.64E+03 2.64E+07

1987 1.29E+03 1.29E+07

1988 1.16E+03 1.16E+07

1989 4.36E+05 4.36E+09

1990 2.01E+04 2.01E+08

1991 4.70E+03 4.70E+07

1992 1.29E+04 1.29E+08

1993 3.28E+03 3.28E+07

1994 3.00E+08 3.00E+12

1995 1.14E+03 1.14E+07

1996 4.07E+02 4.07E+06

Table 17-5: Airborne MFP Release Estimates and Priority Indices a

a

 Note regarding scientific notation: 4.96E+05 equals 4.96×10+5, 

which equals 4.96×100,000 or 496,000. 

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 17 17-13
Year Release, μCi Priority Index, L

1948

1949

1950

1951

1952

1953

1954

1955

1956

1957

1958

1959

1960

1961

1962

1963

1964

1965

1966

1967

1968

1969

1970

1971

1972

1973

1974

1975

1976 5.89E+09 2.95E+13

1977 4.77E+10 2.39E+14

1978 1.17E+11 5.85E+14

1979 1.19E+11 5.95E+14

1980 1.46E+11 7.30E+14

1981 3.53E+11 1.77E+15

1982 2.51E+11 1.26E+15

1983 4.64E+11 2.32E+15

1984 7.37E+11 3.69E+15

1985 1.26E+11 6.30E+14

1986 1.12E+11 5.60E+14

1987 1.50E+11 7.50E+14

1988 1.21E+11 6.05E+14

1989 1.56E+11 7.80E+14

1990 1.13E+05 5.65E+08

1991 5.72E+10 2.86E+14

1992 1.43E+11 7.15E+14

1993 3.34E+10 1.67E+14

1994 1.01E+11 5.05E+14

1995 4.34E+10 2.17E+14

1996 1.12E+10 5.60E+13

Table 17-6: Airborne MAP Release Estimates and Priority Indices a

a

 Note regarding scientific notation: 4.96E+05 equals 4.96×10+5, 

which equals 4.96×100,000 or 496,000. 

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 17 17-14
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-15 

1.E+191.E+181.E+171.E+161.E+151.E+141.E+131.E+121.E+111.E+101.E+091.E+081.E+071.E+06

194419461948195019521954195619581960196219641966196819701972197419761978198019821984198619881990199219941996

Plutonium

Uranium

Tritium

Mixed Activation Products

Mixed Fission Products

RaLa

1019

10181017101610151014101310121011

1010

109108107

106

Priority Index, L

Figure 17-3. Priority Indices for Airborne Radionuclide Releases from LANL Operations 
17-16 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

Table 17-7. Classes of airborne radionuclides with highest priority 

indices for each period of LANL operations 

Years Radionuclide Class with 

Highest Priority Indices 

Range of Annual 

Priority Indices (L) 

1944-1947 Radioactive Lanthanum 6×1011 to 1×1013

1948-1966 Plutonium 7×1014 to 1×1018

1967-1969 Uranium 1×1017 to 1×1017

1970-1974 Plutonium 2×1014 to 3×1015

1975 Uranium 7×1013 to 7×1013

1976-1977 Tritium 3×1013 to 4×1014

1978-1989 Mixed Activation Products 6×1014 to 4×1015

1990 Tritium 1×1014 to 1×1014

1991 Uranium 1×1015 to 1×1015

1992-1996 Mixed Activation Products 6×1013 to 7×1014

Conclusions regarding prioritization of airborne radionuclides 

The LAHDRA prioritization of airborne radionuclide releases shows that, based on LANL compilations 

of releases, plutonium and uranium were of primary concern until the early 1980s. From then until the 

present, MAP radionuclides appear to have been of primary concern. However, in some cases, limited or 

no data were found in LANL compilations of releases for important nuclides such as plutonium 

(D Building data and pre-1948 data), polonium, tritium before 1967, all nuclides pre-1950, and non-point 

source emissions. 

A calculation was completed in October 2006 that analyzed the reported releases from DP West for 

calendar year 1957, using the actual daily stack sampling and analysis reports. This was done to compare 

with the LANL compilation (Andrews ca. 1973) that has been the basis for asserted releases of plutonium 

from LANL. The analysis of the 1957 data by the LAHDRA team showed that 40% of all operating 

hours at DP West Site were not monitored, with the unmonitored periods mostly associated with 

weekends and holidays. Therefore, a method for estimating the hours where the stacks were not 

monitored is needed. The method used by LANL was likely conservative, in that it scaled from operating 

hours to estimate hours in which no stack measurement was made. The LAHDRA review of the 1957 

data also showed that the simple assumptions made in the early 1970s, such as stack and sample stream 

flow rates, were used for all periods. These assumptions appear to have not always been appropriate. 

The air concentration and fallout tray data for the 37-d operating period during 1957 over which the 

Jordan and Black work was performed (Jordan and Black 1958) could be used to benchmark air transport 

models for assessment of airborne releases from DP West Site. However, the LAHDRA project team has 

been unable to identify the 37-d period, and LANL staff have been unable to supply information about the 

Jordan and Black study beyond what is contained in the associated journal paper. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-17 

Comments and Issues 

Data completeness - This prioritization effort was intended to present a “first look” at the scope and 

extent of radionuclides released at LANL over the years of its operation. Because the primary focus of 

LAHDRA was information gathering, limited effort was expended toward entering or evaluating raw data 

identified in historical documents at LANL. In general, the values used in the prioritization came from 

LANL compilations, with adjustments made as available data supported. Little effort was expended to 

analyze the data from logbooks or other more detailed data sources. A significant amount of original 

release information (that is, lab measurements of a filter from a stack) for the 1950s and 1960s is 

available, and could be captured and analyzed if further evaluation of airborne releases is undertaken. 

Polonium - No effluent data have been found for polonium, other than gross alpha measurements of 

buildings and stacks at DP East Site, where polonium and other materials were handled and processed. It 

is known that significant quantities of polonium were used. Due to its shorter half-life, perhaps thousands 

of times more curies of polonium then plutonium were used. In the early years, plutonium was the most 

valuable substance on earth and was held in strict control. However, since polonium was more readily 

available, it was not inventoried as closely as plutonium. Large amounts were used in explosive or 

destructive tests for nuclear weapon initiators. 

An annex to B Building was built by the end of March, 1944. It held a 20-mm, remotely fired, antiaircraft autocannon used for testing scaled-down versions of gun weapon components and gun initiators. 

Operational in April 1944, it had performed nearly 180 experiments by the end of September (about one 

per day) with unknown quantities of polonium and beryllium released (LASL 1944-1945). In August 

1944, a “coffin” was authorized, that is a box operated at negative pressure with a gas mask filtered 

exhaust, to be used to limit contamination of the machine gun and room during experiments with 

plutonium. It was to be placed into operation in September, 1944. While the LAHDRA team has 

addressed releases of beryllium from the B-Building gun testing (See Chapter 20), polonium releases 

from that activity have not yet been addressed. 

Pre-1967 tritium - There are no pre-1967 effluent data for tritium. The LAHDRA project has identified 

documents that refer to significant tritium releases before 1967, in most cases associated with accidental 

or episodic releases. This information is scattered across many historical documents, such as incident 

reports. The LAHDRA team has identified no location in which documents related to tritium releases 

before 1967 have been assembled. If time could be devoted to a directed search of records (some already 

captured by the LAHDRA team and some not) for episodic tritium release data, it is likely that a tritium 

source term for years before 1967 could be bounded. 
17-18 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

Unmonitored releases - In the early years of Los Alamos operations, some plutonium processing facilities 

such as D Building and the facilities at the DP West Site, were designed and operated with positive 

building pressure (LASL 1947) (see Fig. 17-4 below). This could have resulted in significant 

unintentional release of building air out of doors and exit points other than the stacks. Similar release 

pathways could also be active for large facilities such as LANSCE. 

Fig. 17-4. Excerpt from a description of DP Site facilities and their ventilation systems (LASL 1947).

Small contributors - There are a number of nuclides like Mn-54, Au-194, or Ac-227, which do not fall 

into one of the six existing “nuclide sets”. Since there were few data records involving these 

radionuclides, and it is known that these nuclides were not primary radionuclides that LANL was working 

with, priority indices were not calculated. The overall contribution of these nuclides is thought to be very 

small and subsequently no priority indices are computed or assigned in this calculation. 

Beryllium - In the site-wide FEIS (USDOE 1979), Table 4.1.2-8 contains information on explosive tests 

for uranium and beryllium (see Fig. 17-5 below). Using this information, the priority indices in Table 17-

8 were computed based on required dilution volume in liters. Note that the priority index for beryllium is 

five times that of uranium. Furthermore, these data are only from explosive tests, and as discussed in 

Chapters 11 and 20, there were other sources of beryllium such as the beryllium shop and initiator testing. 

 ORF Corrections – In the site-wide FEIS (USDOE 1979), the percentages of various elements 

aerosolized from explosive tests are listed as 10%, or 0.1 (see Fig. 17-5). In this LAHDRA prioritization 

calculation, it was asserted that the Overall Release Fraction (ORF) was 0.001. This was based on a 

combination of Airborne Release Fraction and Respirable Fraction. If the LANL asserted figure of 0.1 

were to be used, the uranium priority index would change significantly for the years in which uranium 

was used in explosive tests. For the LAHDRA prioritization, the ORF value of 0.001 was retained as it 

was judged to be more appropriate. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-19 

Table 17-8. Priority index calculations for depleted uranium and beryllium emissions 

in 1976 based on data from LANL’s 1979 FEIS

Material 1976 Annual 

Usage (kg) 

Percent 

Aerosolized 

Aerosolized 

Quantity (kg) 

Applicable 

Standard (ng/m3

) 

Priority 

Index (L) 

Depleted 

Uranium 1023 10% 102.3 9,000 1.14×1013

Beryllium 25.5 2% 0.51 10 5.10×1013

Pre-1973 LANL plutonium releases – Figs. 19-6 and 19-7 are a table and text, respectively, from the sitewide FEIS that document the 1.2-curie cumulative historical release value for airborne plutonium through 

1972. The assessment of airborne plutonium releases from LANL operations would benefit from further 

examination of airborne plutonium releases before 1948, as there were minimal control measures in place 

during this period. 

Fig. 17-5. 1979 FEIS Data on Uranium and Beryllium in Dynamic Experiments
17-20 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

Fig. 17-6. Cumulative airborne radionuclide releases through 1972 as reported in the LANL FEIS 

Figure 4-8: Pre-1973 Airborne Releases Text (Excerpt from LANL 1979) 

Fig. 17-7. Text regarding airborne releases before 1973 from the LANL FEIS 

ORF Corrections – In the site-wide FEIS (USDOE 1979), the percentages of various elements aerosolized 

from explosive tests are listed as 10%, or 0.1 (see Fig. 17-5). In this LAHDRA prioritization calculation, 

it was asserted that the Overall Release Fraction (ORF) was 0.001. This was based on a combination of 

Airborne Release Fraction and Respirable Fraction. If the LANL asserted figure of 0.1 were to be used, 

the uranium priority index would change significantly for the years in which uranium was used in 

explosive tests. For the LAHDRA prioritization, the ORF value of 0.001 was retained as it was judged to 

be more appropriate. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-21 

Alternate Methods for Characterizing Airborne Releases−

Measurements of Plutonium in Soil as Indicators of Historical Releases 

Until around 1978, releases of airborne plutonium from LANL were either not measured at all or were 

improperly measured or reported. Major release points that were not measured for plutonium include the 

historic D Building, the first plutonium component manufacturing facility in the world, and DP West Site 

releases before 1948. D Building operated until around 1953. Also never considered in LANL 

compilations of plutonium releases were non-point source emissions from major fires at plutonium 

disposal areas in the 1940s and radioactive disposal area operations that continue to this day. Until the 

around 1959, release points such as DP West at LANL were not provided with single stage HEPA filters 

(Maraman et al. 1975). A second stage of HEPA filters were finally installed around 1973. Until the 

mid-1950s, the DP West Site Stacks were not equipped with an appropriate sampling system, resulting in 

underreporting of releases by large factors. Thus, the LAHDRA project had a need to estimate potential 

releases from LANL operations using methods beyond those based on reported stack monitoring results. 

One method identified was to use amounts of plutonium measures in soil samples collected around Los 

Alamos to estimate the amount of airborne plutonium that was released. 

Efforts by LANL

The staff at LANL attempted to measure the amount of plutonium in the soils around LANL in the 1957-

1958 timeframe. Fig. 17-8 is taken from the 1958 publication “Evaluation of the Air Pollution Problem 

Resulting from Discharge of a Radioactive Effluent” by Harry Jordan and Ralph Black (Jordan and Black 

1958). The darker areas in the figure indicate the canyons. The image shows circles of increasing 

distance from the main stacks at D. P. West along with soil sampling results and locations. The authors 

asserted that they were able to compare their values with the actual release data since releases were 

measured at D. P. West. Only the 6 results to the east (right) that are circled were used by Jordan and 

Black because they “show rather remarkable agreement” with the LANL stack effluent records showing 

13.1 g or 0.82 Ci of plutonium (as stated in their own words). Results that were substantially higher were 

not used because they thought that they were higher because of failure of “attempts to avoid extraneous 

contamination.” Although they asserted agreement, they were apparently unaware of or ignored major 

changes in the stack sampling system in 1955 that were the subject of a study by Edwin Hyatt that 

resulted in significant modification of release estimates.
17-22 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

Fig. 17-8. Measurements of Plutonium in Soil at DP West Site as reported by Jordan and Black

The LAHDRA team sees at least five major problems with the Jordan and Black paper: 

1. LAHDRA is unable to find any supporting records or logbooks about the referenced work. 

2. Jordan and Black excluded any high samples, for what appear to have been erroneous reasons. 

3. Jordan and Black compared the soil to incorrect stack monitoring results and asserted that the 

soils and stack data agreed. The DP West stack measurements are now thought to be up to a 

factor of 100 or more in error (lower than the correct value), even without inclusion of pre-1948 

releases at DP West or any other LANL source terms. Edwin Hyatt replaced the stack sampling 

system in 1955 and found that the old system under-sampled the releases by a factor of 

approximately 20 as compared to the 1955 sampler (Hyatt 1955, Hyatt 1956). In addition, 

corrections for sample line loss of up to 5 and filter burial of 2.33 were not generally made until 

the late 1970s (Fuehne 2008). 

4. The lab at LANL analyzed too much soil at once, resulting in low and variable recovery of the 

plutonium from soil in the acid leaching process. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-23 

5. The radiochemist responsible for the soil analysis has stated his results were only intended to be 

qualitative (whether plutonium is present) and not meant to be quantitative (how much plutonium 

is present) (Flack et al. 2004). 

In 1971, other Los Alamos scientists attempted to reproduce the work of Jordan and Black. W. Purtymun 

and W. Kennedy published “Plutonium and Strontium in Soil near Technical Area 21”(Kennedy and 

Purtymun 1971). Their measured soil concentrations were much higher than Jordan and Black’s. In 

order to explain the higher soil concentration, the 1971 report attempted to correct for the small amount of 

global fallout from nuclear weapons testing and also assumed four times more plutonium was deposited 

on the soil from the releases. By assuming four times more plutonium was deposited, Kennedy and 

Purtymun also asserted that their results agreed with invalid and significantly understated stack 

measurements. The LAHDRA team took steps in their evaluation to avoid the problems with the Jordan 

and Black analysis that are identified above. 

 Efforts by the LAHDRA Project Team 

As a result of the lack of valid or accurate effluent measurements for early airborne releases of plutonium, 

the LAHDRA team has considered several nontraditional methods to gain information about the potential 

magnitude of historical plutonium releases. Measurements of plutonium in soil around LANL make up 

an “environmental record” that is a potentially useful indicator of past releases. Members of the project 

team have performed several iterations of analysis to estimate the total integrated airborne plutonium 

release that would be consistent with the environmental record of plutonium found in soil samples in the 

Los Alamos area. 

Initial Assessment

The initial iteration of an assessment by LAHDRA to estimate airborne plutonium releases was based on 

37 measurements of plutonium in soil samples collected near Los Alamos from 1975 to 1977 (Purtymun 

et al. 1980). These measured concentrations of 239Pu in soil included global fallout from atmospheric 

testing of nuclear devices. The average concentration of 239Pu of distant sample sites (approximately 50 

miles from LANL) was 0.006 ± 0.001 pCi g-1. This value was subtracted from the 37 values used in the 

analysis. The “corrected” soil concentrations reflected 0.003 to 0.045 pCi g-1 net positive contributions of 

239Pu from LANL operations. None of these measurements were near the release points. 

The Radiological Safety Analysis Computer program was run with Los Alamos meteorological data to 

calculate 239Pu deposition at various distances in each direction from a unit release (1 Ci) of 239Pu over 50 

y (Schrader 2003). Pasquill-Gifford Stability Class C and a deposition velocity of 0.001 m s-1 were 

assumed. The calculated deposition at each distance was converted to a soil concentration based on the 

annular area involved and the soil density and sampling depth reported by LANL. The ratio of each 
17-24 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

measured soil concentration to the concentration calculated for that same area from the RSAC modeling 

of a unit release yielded a factor that corrects the unit source in RSAC to give agreement between the soil 

data and the RSAC results. For example, a ratio of 15 would indicate that 15 curies of plutonium was 

released rather than 1 Ci. 

The ratios over the 37 sampling locations were log-normally distributed. Based on the distances involved 

with releases from D Building (where plutonium was first processed), the geometric mean was 620 curies, 

with a factor of uncertainty (geometric standard deviation of the mean) of 1.2. For the distances 

associated with releases from the DP Site (where plutonium processing took place from late 1945 to 

1978) the geometric mean was 670 curies, with a factor of uncertainty of 1.3. While these results have a 

high degree of mathematical uncertainty, they indicated that airborne plutonium releases from LANL 

operations could have been hundreds of times higher than the 1.2 Ci officially reported, and were much 

closer to the actual LANL releases. 

Second Iteration

Following the initial analyses based on a small sample size, a search for additional soil sampling data was 

performed, and over 600 soil sample analyses were located (Fresquez et al. 1996). A new analysis was 

done using this expanded dataset. The ratio of plutonium and cesium was calculated using LANL data 

and plotted along with the dry pCi g-1 of plutonium and cesium. Further examination of the resulting data 

plotted as a lognormal cumulative frequency distribution reveals that there are two datasets for plutonium: 

• Those measurements that reflect contributions from LANL operations (“impacted” 

measurements), and 

• Those measurements that reflect no significant contribution from LANL operations, only fallout 

from weapons testing (“fallout” measurements). 

A mean value for fallout from LANL publications that was consistent with the dataset for fallout was 

subtracted from the plutonium to get net plutonium for the “impacted” samples. The values of these 

impacted samples were then plotted on a map at the associated sample collection location. 

Two approaches were then used. First, 679 soil samples at 34 sample points were analyzed. Of these, 

106 samples at 24 sample points were judged impacted based on analysis of the plot of plutonium-tocesium ratios. These points were used for geospatial studies of the location and magnitude of elevated 

levels of plutonium soil concentration. This first approach was oriented towards analysis of the data, not 

towards estimation of LANL releases. The 239Pu to 137Cs ratio is the middle curve in Fig. 17-9. As can be 

seen, the ratio sharpens the differences observed in 239Pu, with a slightly worse fit to a lognormal 

distribution. This ratio helps establish the point at which samples impacted by LANL operations can be 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-25 

detected. A ratio of about 0.065 marks the break (or “knee”) in the line, above which data shows 

evidence of LANL impact, and below which, the site added 239Pu is so low that the variability of fallout 

239Pu and 137Cs masks its presence. This shows that the population of a large number of soil 

measurements can be used to separate the LANL-impacted locations from those that exhibit fallout alone. 

The higher one restricts the data above the ratio of 0.065, the less influence fallout has on the 239Pu 

concentration. 

 

 Fig. 17-9. Cumulative Frequency Distributions of 137Cs, 239Pu, and Pu/Cs Ratio Data 

In the second approach, a total uncertainty for each soil sample was calculated, and only those 

measurements with uncertainty in the plutonium to cesium ratio less than 25% were analyzed. This 

resulted in a data set with 119 members. The plutonium-to-cesium ratio was studied, and the Pu/Cs ratio 

<0.065 criterion was used to select a 37-sample subset of the 119 samples previously selected for low 

uncertainty. These samples lie within 5.5 km of either DP West Site or D Building. The results from use 

of these 37 samples were less dependent on the assumed background from fallout, since the values for 

plutonium were higher and the background is a smaller percentage of the value. 

For these 37 samples, the net plutonium and the range and bearing from the D Building and DP West Site 

were calculated. The RSAC program was used to calculate the soil concentration as a function of wind 

y = 0.6088e0.713x

R2 = 0.993

y = 0.0284e0.825x

R2 = 0.903

y = 0.0466e0.979x

R2 = 0.8755

0.001

0.01

0.1

1

10

-3 -2 -1 0 1 2 3

Standard Deviation

Concentration (pCi/g) or Ratio

Cs-137

Pu-239

Pu-Cs_Ratio

Expon. (Cs-137)

Expon. (Pu-239)

Expon. (Pu-Cs_Ratio)

Pu/Cs ratio = 0.065 
17-26 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

direction and distance for a one-curie source term. When divided into the net sample data, an estimate of 

the integrated LANL source term was obtained for each of the 37 samples. 

The cumulative frequency distribution plots for all 37 sample points for either DP West Site as source or 

D Building as source are shown in Fig. 17-10. The results were log-normally distributed. If the release 

was attributed to the DP Site, an average of 60 Ci and a median of 12 Ci were obtained with a geometric 

standard deviation (factor of uncertainty) of 9. If the site releases were attributed solely to D Building, an 

average of 101 Ci and a median of 46 Ci were obtained with a corresponding geometric standard 

deviation (factor of uncertainty) of 5. The smaller uncertainty for D Building suggests that large and 

previously undocumented releases from D Building could have occurred. However, these results rely on 

many parameters, which should be the subject of further study. The methods established with this 

analysis, when validated, could be extended to other contaminants of concern for which monitoring data 

are not available for key periods of time, such as beryllium. 

Source Term

y = 46.264e1.5901x

R2 = 0.9297

y = 11.744e2.1437x

R2 = 0.9873

1

10

100

1000

-2 -1 0 1 2

Standard Deviations

Source Term (Curies)

D_Calc_Pu

DP_Calc_Pu

Expon. (D_Calc_Pu)

Expon. (DP_Calc_Pu)

Fig. 17-10. D-Building and DP West Site Source Term Fits
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-27 

Finally, an attempt was made to explore the relative contribution of D Building and DP West Site to 

estimated site-total releases. Many combinations of the possible release totals for the two sites were 

analyzed to find the breakdown that best satisfied the following criteria: 

• Minimize the absolute value of the difference between concentrations calculated from LANL 

releases (D Building plus DP West Site) and measured soil concentrations, averaged over all 

measurement locations 

• Minimize the standard deviation of that mean (i.e., minimize uncertainty). 

If one sums a fraction of D Building results with that of DP West Site adjusted for 100% release, the 

curve would lie midway between those shown in Fig. 17-10. The slope progressively decreases from a 

factor of 9 (100% DP West Site) to a factor of 5 (100% D Building). A completely flat curve would show 

that all of the measured soil samples provide the same result, indicating no uncertainties in the answer. 

Thus, although DP Site happens to fit a lognormal distribution better than D Building, the results suggest 

most of the releases came from D Building. 

Additional Refinements– Jordan and Black Revisited

A detailed review of the 1958 Jordan and Black journal paper was performed during 2006. The soil data 

used by Jordan and Black have orders of magnitude variability. When plotted as a function of downwind 

distance, no radial dependence is observed. The air concentration data and fallout tray data are not 

correlated. The issues with these data lead Jordan and Black to select only six data points as 

representative, rejecting 85% of their own data. Using the same six points selected as representative by 

Jordan and Black, the LAHDRA team was unable to reproduce the asserted release, indicating other 

undocumented assumptions may have been used. The asserted release is consistent with the 1973 “Joe 

Graf binders” compilation assembled by LANL for the first site-wide environmental impact statement. 

The deficiencies in that estimate include a lack of pre-1948 data, an estimate for DP West alone for 1948-

1950, absence of sample line loss and burial correction factors, no releases from non-point sources such 

as dumps and dump fires, and no releases from D Building. In summary, the Jordan and Black data lack a 

basis and any supporting information that would permit its use for back-calculation of the plutonium 

source term in air. 

 Material Disposal Area G Calculation

A calculation was completed by the LAHDRA team in November 2006 for non-point source emissions 

from Material Disposal Area (MDA) G. A LANL staff member had objected to use of soil data from that 

area for estimating DP West emissions (Shonka and Mejias 2006). This assessment addresses whether 

soil samples were impacted by MDA G operations, resulting in a falsely high assertion of source term 

from either DP West Site or D Building. The LAHDRA calculation demonstrated that the LANL 
17-28 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

assertion was correct, and that soil samples in that area are significantly impacted by operations at MDA 

G. However, this calculation also indicated that the release of plutonium from MDA G may be the most 

important source of plutonium released by LANL since 1981. This non-point source emission has not 

previously been considered or reported by LANL. The data from one particular location show a gradual 

reduction of soil concentrations over time, which has been reported by LANL elsewhere. This reduction 

implies that back-calculation of source terms from the 1940s could be low for data collected in the late 

1970s and late 1980s if weathering is not considered. 

Identification of Another Potential Dataset for Sampling of Soils Near D Building 

While reviewing the ERSS Domino database in March 2007, a LAHDRA document analyst noticed an 

urgent request in 1993 by LANL staff for soil sampling from the hillside of Los Alamos Canyon, near the 

location of the former Original Technical Area, to support an EPA audit. In response to a request by the 

LAHDRA team, Dave Sarracino from the LANL sample office searched his database and provided a 

printout of sample results associated with that documented request from that ERID (LANL 1993b). 

An e-mail authored by LANL staff member M. McNaughton was added that explained that the sample 

area, depth, and volume were not available because those data were considered not relevant. 

McNaughton went on to opine that the data should not be used for source term calculations since he felt 

the locations were impacted by water runoff from TA-1. 

The data provided by LANL fit a single log-normal distribution (97%) with a median value of 11 pCi g-1

and a geometric standard deviation of 3.3. This indicates that 95% of the data lie within a factor of ten of 

the median of 11 pCi g-1. The previous environmental monitoring data LAHDRA used for source term 

calculations had plutonium levels greater than background (background samples were not averaged in) 

and had a geometric mean that is significantly less (by more than two orders of magnitude) than these 

hillside samples. Because of the closer distance, these results support median release estimates of 

between 1 and 100 Ci, with no correction for weathering. 

Arguments for and against the use of these samples can be summarized as follows. Some LANL staff 

members’ opinions as to why the 1993 hillside/bench top samples should not be used were summarized in 

a 23 October 2007 e-mail from McNaughton that asserts that sampling locations in the 1993 campaign 

were selected to correspond to locations of the effluent pipes known as outfalls numbered 137; 138, and 

140 along with locations down-gradient from these pipes. It goes on to assert that almost all plutonium at 

these locations was therefore carried by water and thus the data were unsuitable for use in characterizing 

airborne releases from D Building. LAHDRA team members believe that the 1993 hillside/bench top 

samples are worthy of evaluation because, aside from McNaughton’s assertions, there is no evidence that 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-29 

the statements in his e-mail reflect the actual case. The referenced McNaughton e-mail was provided 

without references. 

The planned sampling sites appear to follow straight lines and show no meander of a typical gravity flow 

path on irregular terrain. The TA-1 area was documented to have been covered with many feet of clean 

fill following the removal of D Building. This removed the washout source term for up to 40 y (1953 – 

1993). Any water flow over the hillside over the last 40 years would have tended to remove plutonium 

previously deposited along water flow pathways, not add to it. If there is a new or continuing source term 

from TA-1 as McNaughton suggests, LANL would need to remediate or mitigate it. 

The bench top is not a manmade structure, such as a weir, that would have uniform flow over the entire 

area. Surface water under gravity flows along low lying channels. In rocky terrain such as the bench top, 

the flow channels do not change over time as much as in alluvial plains, where episodic floods can change 

the path of a stream. The flow behavior has been observed in that area during rainfall by LAHDRA team 

members. The materials deposited in those channels tend to be variable over the years with gradual 

buildups of sedimentary deposits followed by scouring during episodic high flow periods. Thus, 

waterborne material deposited during the first ten years of TA-1 operations would likely no longer be 

present in 1993 in the water pathways. If the samples along water flow paths simply integrated, as 

McNaughton’s argument implies, then the streams in the bottom of the canyons would be highly 

hazardous locations. 

Thirty nine of the sampling locations (43%) in the 1993 sampling were assigned (one of eight) identical 

values, likely because there was insufficient material at each location to make a sample, and collected soil 

was composited and analysis yielded a single value. Several of the sampling locations (3) were sampled 

to depths of over a foot. The soil concentrations at those sites are similar to others in the data set. These 

locations were likely not along water flow paths. 

The data are well correlated (97%) with a single log-normal distribution, with a median of 11 pCi g-1 and 

a geometric standard deviation of 3.3. If there were two processes at work (areas with or without water 

pathway transport mechanisms), there would likely have been more than one distribution evident. 

The data should be examined for potential utility in characterizing historical releases because of the 

paucity of data regarding D Building releases, which were not measured by LANL. The data could 

provide another “piece of the puzzle” for estimating D-Building releases. 
17-30 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

Suggestions for Improvement of the Current Analysis

The quantity of plutonium released by LANL appears to have been potentially one hundred times or more 

higher than LANL has asserted. However, the historical LANL soil measurements data that are available 

and have been used to date for back calculation of the LANL plutonium source term are not ideally suited 

for this task. Attempts by the LAHDRA team to use existing soil analyses have been critiqued by a 

LANL staff member citing several issues– some acknowledged by the LAHDRA team and some 

disputed. Unless LANL has additional documentation that could clarify this issue, a new program of soil 

sampling, oriented towards resolving the magnitude of releases from significant operations, would be 

desirable. 

The areas around D Building and DP West have been heavily disturbed and suitable soil sampling 

locations would be problematic. A LANL Technician observed that the hillside of South Mesa across Los 

Alamos Canyon from the TA-1 has remained relatively undisturbed. This area should be considered for a 

new program of soil sampling. The samples should continue along the canyon rim from the bridge at 

Diamond Drive to the area across from D.P. West. If possible, the samples should be analyzed with a 

new method of measurement called Inductively Coupled Plasma Mass Spectrometry (ICP-MS). This 

method can distinguish between weapons-grade plutonium samples that have not been used in a nuclear 

weapon and fallout samples with plutonium left over after a nuclear detonation. The United States 

Transuranium and Uranium Registries (USTUR) have performed an initial study of the method with 

promising results. This method and new analysis of the samples might permit accurately estimating how 

much of the plutonium found in any individual living in Los Alamos was due to global fallout and how 

much was due to releases of plutonium from LANL. 

Without any new soil samples, the material found by LAHDRA in various LANL document repositories 

could be used for source term estimation, with a more rigorous effort to quantify uncertainties associated 

with various parameters. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-31 

Analysis of Measurements of Plutonium in Body Tissues of Los Alamos Area Residents 

Before the late 1970s, plutonium releases from Los Alamos operations were either not measured or were 

inaccurately measured and reported by LANL. Consequently, alternate methods are needed for 

determining airborne releases from the early operations at LANL that could have affected off-site 

populations. The LAHDRA project team investigated the use of data concerning the plutonium levels in 

tissues obtained from autopsies of LANL residents to estimate plutonium releases. 

The LANL Human Tissue Sampling Program 

The Human Tissue Analysis Program was a 35-year effort by LANL to study the levels of plutonium in 

workers and in the general population of the United States. The general population was exposed to 

plutonium from atmospheric testing of nuclear weapons. Populations located near plutonium facilities, 

such as the D Building and DP West Site in Los Alamos, were also exposed to plutonium released during 

operations. Fig. 17-11 is an autoradiograph of a lymph node taken from the lung of a deceased worker 

from Los Alamos (McInroy 1995). It shows several groups of alpha tracks (radiating in a typical star 

pattern) from tiny particles of plutonium inhaled while 

working at the laboratory. 

Compilations of the LANL human tissue analysis data 

have been published periodically, and the Los Alamos 

Science magazine summarized the program in the 

November 23, 1995 issue that was devoted to a discussion 

of the Human Radiation Experiments (McInroy 1995). 

Researchers at LANL first began obtaining samples of 

tissues from autopsies performed in Los Alamos at the 

medical center following a nuclear criticality accident that 

resulted in the death of Cecil Kelley in 1959. He had 

worked at LANL for many years and had plutonium in his 

body before the accident. The collection and analysis of 

tissues was intended to answer questions about the 

behavior of plutonium in the human body. In later years, 

the program was expanded to other areas of the country in 

order to estimate the amount of nuclear fallout people were subjected to from the atmospheric testing of 

nuclear weapons. The non-worker tissue program ended in 1980. Nearly 1,000 decedents had tissues 

removed during their autopsies and sent to LANL by coroners. 

Fig. 17-11. Alpha tracks from plutonium 

in former worker’s lung tissue 
17-32 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

The LAHDRA project team considers the human tissue sample data associated with residents of the Los 

Alamos area important because they can support the characterization of public exposures that resulted 

from LANL releases of plutonium during the initial decades of the facility’s operations. In the past, when 

LANL reported results from the human tissue program, comparisons were made between various areas of 

the country. Samples from New York City were taken in the 1967-1968 time frame while samples from 

all other areas of the country (other than near Los Alamos) were taken only over the 1974 -1975 time 

frame. By that time, plutonium releases from LANL had been greatly reduced by the installation of 

HEPA filters on the various exhaust points. Consequently, worldwide fallout from weapons testing 

became an increasingly important source of plutonium exposure for Los Alamos residents. Individuals 

who arrived in Los Alamos after the 1960s might be expected to have mostly experienced intakes of 

nuclear fallout from weapons testing while people who arrived earlier could have inhaled or ingested 

greater amounts of plutonium from LANL releases. 

The comparisons LANL staff have published have considered only the Los Alamos data for individuals 

who died in those limited years (1974-75 or 1967-68), to support comparison with the datasets collected 

from other parts of the country, since cases from New Mexico for earlier years would have been exposed 

to different levels of nuclear weapons testing fallout. Since there are only a few cases for those years, 

data from early and late arrivals; men and women; old and young; etc. were combined. When the 

combined cases data from these few years are compared to other areas of the country, the variability is so 

great that one cannot see if there was a difference between Los Alamos and other areas or not. From this 

result, LANL has asserted that there are no measureable differences between Los Alamos and other areas 

of the country. While this statement is correct, the LAHDRA team believes that it is misleading. 

The data have been analyzed by Los Alamos to demonstrate that the differences in median values of 

plutonium concentration in tissues between states in the U.S. were small. However, the autopsy results 

from deaths at the Los Alamos Medical Center (designated as either Los Alamos residents or residents of 

Northern New Mexico) were generally the highest median values for nearly all organs compared to other 

states. Although other tissues were sampled, the LAHDRA project team is primarily interested in the 

results from the liver, skeleton, and lungs. The lungs provide information about plutonium inhaled in the 

last few years prior to death, while plutonium accumulates in liver and skeleton and provides an estimate 

of the total plutonium inhaled over a person’s life. Because of relatively slight differences in the time 

(decades) that plutonium remains in either the liver or skeleton, it is possible to observe differences 

between people who were exposed to plutonium long ago and people who had more recent exposures. 

The LAHDRA Project located and copied the death certificates from workers and residents of the Los 

Alamos area who contributed samples to the program (LANL 1978). The addresses of many of these 

individuals were obtained from cross referencing with the yearly listings in the telephone directories 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-33 

maintained by the Los Alamos Historical Society and from other LANL documents and public records. 

The logbooks from the human tissue sample program and solutions of many of the sampled tissues were 

transferred by LANL to the United States Transuranium and Uranium Registries (USTUR) after the 

program ended. USTUR maintains them still today. 

The exposure to fallout plutonium in an area would be broadly similar for most individuals who share 

similar lifestyles. However, the exposure to releases from plutonium facilities would not be similar, since 

individuals residing closer to the facility would generally have experienced greatest exposure to releases. 

These individuals might be a small subset of the total population. This subset, individuals residing close 

to a nuclear facility, might not significantly alter the median value of a dataset, especially when small 

numbers of samples are all the data that are available. 

Analysis of the Autopsy Program Results by the LAHDRA Project 

The LAHDRA staff attempted an independent analysis of the autopsy program results (Shonka 2004). 

This effort demonstrated that excess plutonium is present in non-worker residents of Los Alamos over 

what would be expected from global fallout from nuclear weapons testing. It also established and tests a 

method for uncovering the history of residence locations for autopsy cases. This history establishes the 

range and bearing from LANL release points along with the years of occupancy at each residence. This 

method could be used to reduce the uncertainty in retrospective dose reconstructions and possibly permit 

use of the autopsy data for bounding LANL releases. 

The data from the residents who were present in Los Alamos can be used to estimate exposures for any 

resident of Los Alamos and also be used to provide upper and lower bounds on the plutonium source term 

from LANL operations. A full analysis of the data would require that the range and bearing from 

significant release points at Los Alamos, along with the time dependent source term, be incorporated into 

a model. Additionally, the date of death should be used in correcting the autopsy results for fallout. 

From the results of this calculation, the median estimated exposure is a factor of 5 times higher in the 

long-term residents, while the geometric standard deviation is reduced by 20% from that of all Los 

Alamos residents taken as an aggregate population. This implies that stratifying the population results 

can significantly improve (that is, reduce the uncertainty) of the estimate of the potential exposures that 

an individual in Los Alamos received from past operations. The current model does not remove the range 

and bearing impact on the results, and further improvements are suggested. 

Another use of this analysis would be the application of this method to estimate worker exposure for 

LANL workers who were not considered plutonium workers, and did not receive routine internal 

dosimetry. 
17-34 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

Methods

The method used in this calculation was as follows: 

1. Enter the data from the 1979 Health Physics journal paper (McInroy et al. 1979). 

2. Conduct a public records search for information on Los Alamos residents in that journal article. 

3. Calculate the ratio of deposited plutonium in the liver vs. vertebrae. 

4. Plot the standard deviation of Pu Ratio for the populations of Los Alamos and Denver. 

5. Draw conclusions about the individual cases in Los Alamos and possibilities of exposure. 

Dose Estimates from Exposure of Organs to Plutonium

The autopsy data are provided for various organs in units of disintegrations per minute (dpm) per kg of 

organ. The following material is presented to assist in understanding what these units (dpm kg-1 organ) 

mean in terms of dose or risk. A fraction of the plutonium present in inhaled air is retained in the lung. 

The lung retains the plutonium for about a year or a year and one-half. Thus, the autopsy data for lung 

tissue largely reflects the plutonium air concentration for the last few years prior to death. Since most of 

the autopsies are from the 1960s and 1970s, the lung data largely reflect atmospheric fallout from the 

testing of nuclear weapons. The largest plutonium releases from Los Alamos appear to have occurred in 

the 1940s and 1950s. This plutonium, if measurable, would no longer be present in lung tissue. 

The International Commission of Radiological Protection (ICRP) Report No. 30 model of plutonium 

behavior in the human body (ICRP 1979) distributes plutonium present in systemic circulation, with 45% 

going to the liver, 45% to bone, and the remainder going largely to excretion. Small fractions are 

assigned to other organs. The liver and skeleton retain the plutonium for decades. Reference Man (ICRP 

1975) notes that Thoracic Vertebrae are 75% trabecular, the spongy bone in which marrow resides. Thus, 

the vertebrae and liver are appropriate tissues to sample to measure plutonium deposited in an individual 

over a long period. The program at LANL sampled these two tissues, along with other tissues such as 

lung. 

The autopsy data are provided in dpm kg-1 organ. It may be of some use to understand the potential doses 

that are involved with the measured data. The dose, in rem per dpm kg-1 skeleton, can be derived as 

follows: a systemic uptake of 1 dpm ultimately results in 0.45 dpm in the skeleton or liver. The liver has 

a mass of 1.8 kg in Reference Man, resulting in 0.25 dpm kg-1 in liver tissue for each dpm that is 

incorporated into the body. 

A conversion for the skeleton depends on the type of tissue sampled. The entire skeleton ranges from 

10% to 20% trabecular bone by weight. If the tissue sample had the same proportions, one could divide 

by about 2 kg (or 20% of the 10 kg total mass of skeleton) to yield a value of 0.225 dpm kg-1 skeleton. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-35 

This value is close to that for liver. It has also been noted that the plutonium concentration in bone (from 

humans) is inversely proportional to the percent bone ash (McInroy et al. 1979). Plutonium is 

concentrated in the trabecular bone rather than hard, compact cortical bone. Each person is, of course, 

unique and their weights are not the same as the average that is expressed in Reference Man. The LANL 

compilations provide the actual dpm kg-1 organ, and express the data as if the individual had the same 

weight organ as reference man. 

The dose resulting from a 1 dpm systemic uptake depends on the chemical form of the intake (and of 

course the isotope, particle size, etc.). For inhalation of 239Pu oxide, Federal Guidance Report No. 11 

asserts a dose factor of 8.21×10-04 Sv Bq-1 for bone surfaces, which converts to 1.37 mrem dpm-1 (intake) 

(USEPA 1988). Dividing 1.37 mrem by 0.225-dpm kg-1 skeleton then gives 6 millirem committed bone 

dose per dpm kg-1 skeleton. 

The committed effective dose equivalent (CEDE) is a measure of radiation exposure that estimates risk by 

adding the dose from all of the organs (weighted for their risk for cancer) for as long as the radioactive 

material will be present in the body. On the basis of CEDE, the value for 239Pu oxide is 0.6 mrem CEDE 

per dpm kg-1 skeleton, or 0.6 mrem CEDE per dpm kg-1 liver. For more soluble forms (inhalation Class 

W), the values for 239Pu are 16 and 0.9 mrem per dpm kg-1 skeleton for bone surfaces and CEDE, 

respectively. Values for 238Pu are similar to those for 239Pu. A simplification that expresses the results in 

the right “ballpark” would be that 1 dpm kg-1 results in approximately one mrem CEDE for either liver or 

vertebrae results from the autopsy program. 

Fallout Levels of Plutonium

The plutonium deposition from worldwide fallout in the Los Alamos area has been reported by LANL 

(Purtymun et al. 1990). Soil and river sediment samples were taken. The data were reported in units of 

concentration, fCi g-1. One can convert the concentration measured in soil samples to areal deposition by 

multiplying the concentration by the mass of soil sampled and dividing by the total area of the samples. 

This conversion is needed to be able to compare the LANL data with that taken by the Environmental 

Measurements Laboratory (EML) as reported by Krey for the Denver area (Krey et al. 1976). Krey 

reported fallout for the Denver area as 1.7± 0.5 mCi km-2. Krey’s data did not include the contribution to 

fallout from Chinese testing in the late 1970s that may be present in the LANL data from the early 1980s. 

Krey’s data also would not have included any weathering that might have occurred between the time of 

the Denver samples and those taken around Los Alamos. Both of these minor influences would likely 

offset one another, since weathering would tend to decrease the values and the Chinese testing would tend 

to increase the values. 
17-36 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

Each site sampled by LANL consisted of a square area 9 m on each side, with soil collected from each 

corner and the center. Each sample was 7.5 cm in diameter and 5 cm deep. The samples were combined 

to form a composite sample. The total volume of soil collected was 1100 cm3

, which would weigh nearly 

2 kg at an estimated average soil density of 1.8 g cm-3. This is believed to be a conservative (high) soil 

density, which will overstate the fallout levels compared to values if a lower soil density value were 

assumed. The area collected by the LANL sampling method was 221 cm2

. 

Plutonium release estimates put forward by LANL staff have been found in LANL documentation for 

1948 – 1973. This total value is approximately 1.2 Ci (Andrews ca. 1973). This activity could 

contaminate an area of 1200 km2

 (assuming an unrealistic completely and uniform fallout distribution) to 

a level of 1 mCi km-2. Thus, the sampling for background levels of plutonium in Los Alamos would have 

to be outside of a radius of 20 km to avoid including the impact of site operations in the results (a radius 

of 20 km includes approximately 1200 km2

). 

As described by Purtymun, six sites within a 50-mi radius of Los Alamos were sampled in 1981 and 

1983, and additional locations along the continental divide were sampled in 1986. In fact, the sampling 

locations were located at approximately a radius of 50 mi, or 80 km. Thus, the sampling locations were 

far enough removed from the site to avoid significant impact from LANL releases if the releases were on 

the order of curies. 

In the Purtymun study, the average of the 239Pu results for the six sites within the 50-mi radius near Los 

Alamos over two years was 8.75 ± 5 fCi g-1. The data appear to fit a normal distribution with a better 

correlation than a lognormal distribution. In areal deposition, this value corresponds to approximately 0.8 

± 0.5 mCi km-2. The integrated level of fallout plutonium for Los Alamos (Purtymun et al. 1990) appears 

to be about one-half of that for Denver (Krey et al. 1976). If the soil density is lower, then the fallout 

plutonium levels found by Purtymun are even smaller than one-half of those found by Krey near Denver. 

Further Interpretation of the Autopsy Data 

The autopsy data reported by McInroy et al. in 1979 in Health Physics shows that the cumulative 

frequency distributions of liver concentrations (dpm kg-1 liver) are nearly identical between Los Alamos 

and Denver. However, the vertebrae autopsy samples from Los Alamos are higher than Denver, and their 

different slope indicates the plutonium has been in the body longer. These data are shown in Fig. 17-12 

and Fig. 17-13. To facilitate comparison, the figures from McInroy et al. were superimposed on one 

another in those figures. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-37 

Fig. 17-12. Liver Autopsy Results 

Fig. 17-13. Vertebrae Autopsy Results 
17-38 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

If Los Alamos indeed had one half (or less) of the fallout as Denver, the liver results should show this. 

However, this is not the case. The liver data would seem to indicate the plutonium present at Los Alamos 

is roughly equal that of Denver. If one accepts the earlier fallout data from Purtymun and Krey, then this 

implies that the “extra” or “added” plutonium (that which makes the plutonium liver concentrations 

equal) is due to LANL emissions. The liver results show that autopsy samples from residents of Los 

Alamos appear to have “added” plutonium. If there were two distinct populations, one might expect to 

see a bend in the curve indicating added plutonium in the fraction of the population living nearest the 

release points. However, no bend is seen. This is probably due to the fact that if the added plutonium 

was due to facility operations, one might expect that the impact would be sporadic, with only a few 

individuals impacted based on the winds and other factors. It is likely that releases from the site were not 

sufficient to cause this “bend” in the CFD plot or that the inherent variability of various factors dominates 

the distribution and masks the presence of two populations. 

Conclusions

The vertebrae results show differences between Los Alamos and Denver, with the differences occurring 

in the population with higher bone concentrations. This result also appears to be consistent with a 

hypothesis that releases at Los Alamos impacted the population. 

The data also show significant divergence in the ratio of concentrations in the skeleton to that of the liver. 

Fig. 17-14 shows a cumulative frequency distribution graph for the ratio of vertebrae results to those of 

liver for all autopsy cases that had data for both organs. Four sets of data are shown, with two sets also fit 

to an exponential distribution. The two data sets with fitted exponentials are for Denver and Los Alamos. 

The other data sets are discussed in the next section. 

The curves and data regarding vertebrae to liver ratios were not reported by McInroy et al. The 

information in Fig. 17-14 was computed as an element of this calculation. In general, the cases with 

positive results for both liver and skeleton would be the cases with highest reported data. The results 

from Denver appear to be log-normally distributed about a median ratio of 1.73. One individual (out of 

38) had nearly 25-times as much plutonium in their vertebrae as in their liver. 

The Los Alamos data (with a median ratio of 2.72) has three of the 17 results greater than 25, with one 

result approaching a ratio of 200 (off scale and not shown in Fig.17-14). The value of 2.72 indicates 

plutonium exposures that happened longer ago than those associated with the lower ratios. This is due to 

the difference in clearance time of plutonium from liver vs. vertebrae.
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-39 

y = 2.7189e1.9734x

R2 = 0.9543

y = 1.7301e1.3426x

R2 = 0.9956

0.1

1

10

100

-2 -1.5 -1 -0.5 0 0.5 1 1.5 2

Standard Deviations

Vertebrae/Liver Ratio

Pre-50 GPS'd

Post 50 GPS'd

Los Alamos

Denver

Expon. (Los Alamos)

Expon. (Denver)

Fig. 17-14. Cumulative Frequency Distribution of Vertebrae-to-Liver Ratios 

The ICRP model for plutonium behavior in the human body assumes that the skeleton retains plutonium 

with a biological half-life of 50 years, and the liver retains plutonium for 20 years (McInroy et al. 1979). 

When coupled to the results shown above, there appears to be an indication that not only is there added 

plutonium from site releases present in the autopsy samples obtained from Los Alamos, but also that the 

plutonium in Los Alamos residents appears to be due to exposures to plutonium that were earlier (longer 

ago) than atmospheric weapons testing exposures in the Denver population. It is important to note that 

the Denver population was not significantly exposed to plant releases from Rocky Flats. The downwind 

direction from Rocky Flats is predominately toward the east, and although there are persons living in this 

area, the population density is very low, and the likelihood that those persons were included in the Denver 

study is very low. 

A vertebrae-to-liver ratio of one would be indicative of recent exposure. Larger ratio values would 

indicate that the exposure occurred at some point in the past, or that the exposures were higher in the past 

than more recent ones. An exponential function provides a good fit to the data shown in Fig. 17-14, 

which implies that the data are log-normally distributed. The median value, read from the chart at zero 

for the “X-Axis”, shows a value of 1.73 for Denver, corresponding to less-aged exposures. Los Alamos 

shows a median value for the vertebrae-to-liver ratio of nearly 2.72. The geometric standard deviation is 

2.3 times larger for Los Alamos compared to Denver. If the air concentration had been constant over 
17-40 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

time, this would be a ratio indicative of exposure that began about 10 y prior to autopsy. Given the large 

values of the ratio for Los Alamos, these data indicate that exposures in the early years were higher than 

the later years. 

Reduction of the Uncertainty in Autopsy Results

The publicly released autopsy results were published as blind samples, with no information concerning 

identity or residential history for each case. In a small city such as Los Alamos, relatively few deaths 

occurred each year. The LANL autopsy data had five attributes that could be used to establish the 

identity of the donor without obtaining the data from official or private records: (1) year of death; (2) 

resident of the City of Los Alamos; (3) sex; (4) age; and (5) cause of death. These five attributes were 

used to match a number of the autopsy cases to Los Alamos area residents. 

Death certificates and an index key for participants in the autopsy program were found in the LANL 

Archives during 2006 (LANL 1978). The death certificates facilitated development of residence histories 

for each autopsy case. The documents included information regarding the “usual residence” of the 

decedent, as well as the “length of stay” in the place of death. In instances where the individual died in 

Los Alamos and was also a resident of Los Alamos, this value was considered to be the length of time 

that the person lived in Los Alamos. 

For each participant who reportedly lived in Los Alamos, historical telephone directories were consulted 

for the years that the decedent was expected to have lived there. Directories were available for the years 

1943-1944 and 1946-1969. None were available for 1945. Addresses were listed as street addresses 

beginning in 1948. In the 1943, 1944, 1946, and 1947 directories, addresses were listed as “T-numbers.” 

Each house in the town was assigned a unique T-number. Historical maps of the original Technical Area 

were used to identify the exact location (latitude/longitude) of the T-number addresses. Several other 

sources were also consulted, including a September 1956 Atomic Energy Commission Albuquerque 

Operations Office directory, USAEC Los Alamos directories 1966-1972; a 1968-1969 Los Alamos school 

directory, and a 1964 Albuquerque Operations phone book. 

For each name listed in the human tissue program information database, the “year of arrival in Los 

Alamos” and “length of time in Los Alamos” variables were used to determine in which directories each 

participant would likely be listed as a resident. In instances where the database contained two estimates 

of the “length of time in Los Alamos,” the estimate corresponding with the greatest number of years was 

used in this search. For each year that it was believed the participant lived in Los Alamos, the 

corresponding phone directory was consulted to find their address for that year. In many cases, 

participants lived at a given address for more than one year and the variables “begin year” and “end year” 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-41 

were associated with each address. The 2-3 years preceding and following the time period during which 

it was believed that the participant lived in Los Alamos were also checked in the telephone directories. 

For participants that could not be located using the historical telephone directories, several other 

approaches were available. Obituaries printed in the Los Alamos Monitor, which was published several 

times per week, often provided detailed information regarding how long an individual lived in Los 

Alamos and, in some cases, where they lived. If address information was not directly provided, 

residential histories could also be determined by searching under family members’ names during the 

relevant time periods. Ninety names were searched using this method and 36 matches were found. 

Marriage licenses often contained an address at the time of the marriage, but were also used to confirm 

familial relationships between some of the participants (such as father/daughter versus spouse). In some 

instances (particularly for women), the residential history could easily be tracked in the phone directories 

using the spouse’s name. One hundred and two marriage licenses were searched for using this method and 

nine matches were found. Lastly, online genealogy services were used as an additional source of 

information. 

In total, there were 236 autopsy cases for which tissue activity data were available, with 60 of those 

participants having been LANL employees. Associated with these participants were 809 residential 

locations, of which 677 were identified as addresses and 542 could be geocoded using an Internet-based 

service so that distance to D Building and DP West could be calculated. For some addresses, a global 

positioning satellite (GPS) unit was used to determine coordinates. In some cases, the historical address 

is no longer a residence. To support spatial analysis, geological coordinates were obtained for the 

addresses of the participants using Tele Atlas®. For each address, range from D Building and DP West 

were calculated. 

Fig. 17-14 on Page 17-39 also shows two sets of data plotted as cumulative frequency distributions: pre1950 data and post-1950 data. The plot of post-1950 data is uncertain due to there being only three cases 

with data for vertebrae and liver, one of which is the outlier. The pre-1950 data has a larger median and 

slightly smaller geometric standard deviation than that shown for all data from Los Alamos. 

Additional Avenues for Investigation

Solutions of the original samples taken under the LANL human tissue analysis program, as well as 

logbooks associated with the program, have been maintained by USTUR for many of the autopsy cases. 

Because of that, it may be possible to determine how much of any autopsied individual’s exposure was 

due to fallout or releases from LANL. A new method of measurement called Inductively Coupled Plasma 

Mass Spectrometry (ICP-MS) can distinguish between weapons-grade plutonium that has not been used 

in a nuclear weapon and plutonium from fallout that resulted from a nuclear detonation. USTUR has 
17-42 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

performed an initial study of the method with promising results. This method and new analysis of the 

samples might permit accurate estimation of how much of the plutonium found in the tissues of any 

former Los Alamos resident was due to global fallout and how much was due to releases of plutonium 

from LANL. 

LAHDRA project team members have discussed the case of a clerical worker who worked near D 

Building and whose tissues were obtained for the autopsy program. It was suggested that the case might 

be a limiting case for exposure to plutonium for residents, since that individual was closer to the D 

Building than nearby residences. LANL staff analyzed that case in detail in a recent publication entitled 

“Los Alamos Study of Early Los Alamos Internal Exposures to Plutonium” (Miller et al. 2008). The 

clerical worker case was summarized in Table 3, “Bioassay Data for Clerical Worker.” LANL staff went 

on to conclude the following: 

“Also of interest is the possible inhalation dose to members of the public in these days resulting from 

releases from the Los Alamos facilities. The dose was calculated for a clerical worker who was part of the 

Los Alamos plutonium autopsy study and had tissue burdens higher than those for others in the group of 

Los Alamos workers having low potential for exposure. A dose of this magnitude probably represents an 

upper limit for dose to workers who were not plutonium workers or who were merely town residents.” 

The data for the identified worker are summarized in Table 3 of that article. LAHDRA team members 

take issue with at least aspects of this analysis. First, the method used for assessing her exposure was a 

Bayesian method pioneered by LANL but not generally used for internal exposure elsewhere. In 

particular, the Energy Employees Occupational Illness Compensation Program Act (EEOICPA) project 

administered by the National Institute for Occupational Safety and Health (NIOSH) has declined to use 

this method for LANL cases. The use of Bayesian methods requires a priori assumptions that affect the 

final result. While these assumptions are not sufficiently detailed in the Miller et al. article to reproduce 

their results, careful reading of the article appears to indicate that the variability of the LANL resident 

data set was not considered or included in the assessment. The assessment was purported to be for the 

clerical worker, but as can be seen with the data from Los Alamos residents, human variability is large 

and failure to consider it is a major issue with the analysis. Thus, while the result may apply to that 

individual, the study failed to address all of the uncertainties that would permit LANL to assert their 

conclusion that it also applies to the resident population. 

After LAHDRA team members examined Table 3 of the Miller et al. paper, they were unable to find the 

stated clerical worker’s bioassay data in any of the human tissue sample program publications or 

supporting materials obtained from Los Alamos. This issue was raised with LANL, and a response was 

provided that stated that LANL was unable to determine which case was represented, and also was unable 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-43 

to find any matching data in the autopsy cases (Eisele 2008). They LANL staff went on to offer that the 

data came from a phone call to J. McInroy, the retired manager of the program. Table 3 of that 

publication might be in error, as the information presented does not agree with previous LANL 

publications of the data. LAHDRA project staff have been unable to determine if any of the other tables 

in that publication were also affected. The LAHDRA project team believes that this case is one of many 

that could be used to assess the impact of D Building releases on Los Alamos residents, but are not 

convinced that the data for the referenced clerical worker, if they can be located, will serve as a 

meaningful bounding case for any evaluation. If properly analyzed, the results and the results of other 

town residents would be useful for assessing the potential impacts of historical releases of plutonium from 

Los Alamos facilities. 

LAHDRA team members and USTUR personnel have shared information concerning the autopsy results. 

A complete computer printout from the program dated 1991 has been obtained that can be reviewed 

against the publications that document the autopsy results. This printout has information in it that is 

protected under the Privacy Act, and cannot be released to the public. Attempts are underway to “clean 

up” the old computer output so that it can be scanned and optical-character-recognition processed to 

support entry into a spreadsheet to facilitate analysis. If that task is successful, the data from previous 

publications that LAHDRA currently uses (from the 1980 time frame) will hopefully be reconciled with 

the LANL data. 

A review of other autopsy cases from New Mexico was made in an effort to review the possible 

plutonium exposure from the 16 July 1945 Trinity test. That review showed that there are no cases in the 

highest exposure contours of the downwind plume area as delineated by Quinn (Quinn 1990). The 

highest recorded plutonium levels were a woman from Truchas, New Mexico who was old enough to 

have been alive at the time of the Trinity test. Her liver concentration was 60 times higher than the 

average New Mexico resident. Truchas is next to the 1 mR h-1 contour line (at H+12 hours), which is 

does not reflect doses from inhalation or ingestion of radioactive material (Quinn 1990). 
17-44 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

Prioritization of Waterborne Radionuclide Releases 

Since 1944, operations undertaken at LANL 

have produced liquid wastes containing 

radioactive materials. Waterborne 

radioactive waste was released without 

treatment to Acid Canyon from 1944 to 

1951 (see Fig. 17-15), when a treatment 

plant became operational. The LAHDRA 

team calculated Priority Indices for 

waterborne radionuclides in the following 

categories: total plutonium, 238Pu, 239Pu, 

89Sr, 90Sr, tritium, gross alpha, and 

gross beta radioactivity. LANL also 

reported the following radionuclides at 

various times over the years; effluent data 

were tabulated but priority indices are not 

presented herein for 140Ba/140La (radioactive 

lanthanum), 227Ac, 241Am, 7

Be, 134Cs, 137Cs, 

57Co, 60Co, 54Mn, 22Na, 83Rb, 84Rb, 75Se, 

85Sr, and 88Y. It is important to note that data 

were not available for all radionuclides for all 

years. For example, from 1962 through 1971, 

239Pu measurements were not reported, but total plutonium measurements were. The reasons for the 

changes in nuclides analyzed and/or reported over time are not known. In some later years, uranium 

measurements were made, but associated results were stated in terms of milligrams of uranium of 

unstated 235U enrichment. As a result, since information that has been reviewed indicates that overall 

waterborne releases of uranium were relatively low, uranium was not evaluated in this assessment. The 

radionuclides named above are the only radionuclides for which historical compilations of liquid releases 

prepared by LANL were found. 

Data Sources 

Three main data sources for waterborne radioactive effluents from LANL operations were found by the 

LAHDRA team: 

Fig. 17-15. During early Los Alamos operations, untreated 

liquid radioactive wastes were discharged to Acid Canyon 

through this pipe.
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-45 

• (Andrews ca. 1973) – “Joe Graf Binders” 1 and 2– Two binders of documents assembled by 

LANL Environment, Safety, and Health (ES&H) staff for group leader Joe Graf in the early 

1970s that document releases from LANL before 1973. This was done to support development of 

a draft site-wide Final Environmental Impact Statement (FEIS). The FEIS was finally published 

in 1979. The documents assembled in these binders include records of room air concentrations, 

stack monitoring data, ES&H reports, and miscellaneous memos. 

• (LAHDRA 2000) – Excerpts and compilations of AEC-789T “Radioactive Effluent/Onsite 

Discharges/Unplanned Releases” forms. 

• LANL Annual Environmental Surveillance Reports from 1971-1996. These contain effluent 

information for TA-21, TA-50 and TA-53 waste treatment plants. Data from these published 

reports took precedence over other data that were found (LASL 1971, 1972a, b, 1973, 1974, 

1975, 1976, 1977, 1978, 1979, 1980, LANL 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 

1989, 1990, 1991, 1992, 1993a, 1994, 1995, 1996, 1997). 

Priority index (PI) values were calculated by computing the volume of liquid that would be required to 

dilute the annual activity released to be equal to the worst-case maximum effluent concentration 

documented in Title 10 of the Code of Federal Regulations, Part 20 (USNRC 2003). The priority indices 

are intended to be guidelines for determining if a nuclide set requires further iterations of calculation and 

refinement, or if it warrants lower priority relative to other radionuclides (O'Brien and Burmeister 2004). 

For example, a PI of 106

 indicates that 1 million L of liquid (water) would be required to dilute the 

released material to a concentration equal to the maximum effluent concentration. The priority index 

approach does not consider dilution and dispersion that can occur between the release point and points of 

potential public exposure. Although the lowest available (most conservative) effluent concentration 

limits are used, the priority indices do not otherwise address uptake factors. They do not consider decay 

in transport, which means as calculated, the priority index approach would tend to overstate the 

importance of short-lived materials. Within these limitations, PIs provide a simple tool for establishing 

the relative importance of various liquid-borne releases. 

Priority Index was calculated as follows: 

( ) 1

1

1

, 1,000 −

−

−

= × mL L

Maximum Effluent Concentrat ion in Ci mL

Total Nuclide Activity Released in Ci y Priority Index PI L

μ

μ
17-46 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

The maximum effluent concentration values shown in Table 17-9 were used (USNRC 2003). The 

concentration limit used for gross alpha radioactivity was the value for 239Pu, which has the same value as 

238Pu, and the value for 89Sr was used for prioritizing releases of gross beta radioactivity. 

Table 17-9. Maximum Effluent Concentrations Used for Waterborne Radionuclide Prioritization 

Nuclide Category Maximum Effluent Concentration (μCi mL-1) 

Gross Alpha Radioactivity 2.00×10-8

Gross Beta Radioactivity 8.00×10-6

3

H 1.00×10-3

Plutonium 2.00×10-8

238Pu 2.00×10-8

239Pu 2.00×10-8

89Sr 8.00×10-6

For the years 1948 to 1996, LANL liquid waste and effluent data were collected and analyzed by the 

LAHDRA project team. No summary data were found for the years 1974, 1975, or 1976. Given the 

releases in years preceding and just after that period, and considering the operational history documents 

that were reviewed, it is considered unlikely that releases during these missing years would significantly 

change any of the conclusions of this prioritization if they were found. A Microsoft Access® database 

was created to tabulate the effluent data that were captured and to link them to specific LANL documents 

that were assembled by the LAHDRA project team. In most cases, these documents are available as 

scanned document images as Adobe Acrobat® Portable Document Format (PDF) files. The database 

records in turn link to associated document image files to allow viewing of the actual LANL references 

for the data of interest. That database is called the Off-Site Releases (OSR) database and contains 

information for both airborne and waterborne effluent data. 

Summary of Results for Prioritization of Waterborne Releases 

Table 17-10, Table 17-11, and Table 17-12 comprise the summary data for the prioritization of 

waterborne radionuclide releases from LANL. The first two tables present annual releases of the various 

radionuclides, in curies. The third table presents priority indices for each radionuclide on an annual basis, 

calculated as the dilution volume required for dilution of the reported release quantity to the MPC. It was 

determined that the radionuclides in Table 17-12 were relatively insignificant due to the very low activity 

reported; therefore in Fig. 17-16, the plotted nuclides of interest are Pu, 238Pu, 239Pu, 89Sr, 90Sr, 3

H, gross 

alpha, and gross beta radioactivity. In this calculation, a data cutoff of 1996 was used since it was 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-47 

deemed that this was far enough into the modern era, and prioritization was primarily focused on earlier 

eras before treatment and monitoring capabilities had developed. 

Plutonium: Waterborne plutonium effluent data throughout the years have been reported as Pu, 238Pu, or 

239Pu. During the very early years of LANL operations, the constant value reported for plutonium would 

suggest that there was one number that was “spread” among those years as an estimate. In later years, for 

which plutonium measurements were specified for several nuclides including 239Pu, the LAHDRA project 

team entered the values into the database as 239Pu. For instance, for 1993, plutonium was reported as Pu238,239,240 and was entered into database as 239Pu. Then again in 1994, plutonium releases were 

reported as Pu-238,239,240, but as 238Pu and 239Pu for both 1994 and 1995. In this case, the plutonium 

was entered as 238Pu and 239Pu. Separate radionuclide reporting was used whenever possible. The priority 

indices for plutonium range from approximately 107

 to around 1011. See Table 17-10 for annual release 

totals in curies (Ci) and Table 17-12 for priority indices (dilution volume, L). 

Strontium: The priority index values for strontium range from 105

 to 109. It is important to note that 

LANL changed reporting conventions for strontium several times. Sometimes 89Sr and 90Sr were reported 

separately, and sometimes they were not. In the later years, when 89Sr is not reported separately, the 

strontium values were recorded as 90Sr in the database by the LAHDRA project team. This may result in 

increased PI values for 90Sr, but since the MPC for 90Sr is lower than that for 89Sr, this is a conservative 

assumption. Note that from 1989 to 1995, 89Sr was either not in the compilations or was reported as Sr82, 85, 89, and 90 all in one. These data were entered into the database as 90Sr. That is why 89Sr does not 

show data points in Fig. 17-16 for those years. Subsequently, it appears that 90Sr has increased in priority 

relative to 89Sr for these years. See Table 17-10 for annual release totals in curies (Ci) and Table 17-12 

for priority indices (dilution volume, L). 

Tritium: The PI values for tritium range from 106

 to 108. Based on the currently available information, it 

would appear that tritium warrants lower priority than the other radionuclides. See Table 17-10 for 

annual release totals in curies (Ci) and Table 17-12 for priority indices (dilution volume, L). 

Other Radionuclides: In Table 17-11 there are reported effluent values for other reported radionuclides. 

PI values calculated for these radionuclides ranged from 104

 to 108, except for one 227Ac value at 1011 and 

several 241Am values of 109

. There were a number of these radionuclides present, but none in 

concentrations that would yield greater priority indices than the primary nuclide set. The information for 

these “other” radionuclides is included for completeness. 
17-48 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

Conclusions regarding prioritization of waterborne radionuclides 

It is important to note that the information compiled here is for waterborne effluents. The current results 

indicate that, based on the assembled information as evaluated to date, plutonium would warrant the 

highest concern for waterborne radionuclide releases. It is not yet possible to definitively address the 

relative importance of waterborne effluents versus airborne effluents. It can be noted that, in general, 

pathways for public exposure from liquid releases appear to have not been as complete as those for 

airborne releases, due to the ephemeral nature of surface water flow in many cases, with a large part of 

off-site transport possibly occurring during heavy rains or runoff from periods of snow melting. 

Comments and Issues 

In the later years, when plutonium or strontium radionuclides were not listed by nuclide separately, values 

were entered into the database as 239Pu and 90Sr, respectively. This may have result in increased PI values 

for 239Pu or 90Sr. Since the maximum effluent concentration values for these radionuclides are lower than 

for their sister radionuclides 240Pu and 89Sr, this was a conservative assumption. There were two years 

(1970 and 1971) for which gross gamma radioactivity was reported (LAHDRA 2000); however, because 

LASL’s Annual Environmental Surveillance report for 1971 did not include gross gamma measurements, 

the data on gross gamma for 1970 and 1971 were not included in this work. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-49 

 a Note regarding scientific notation: 4.96E+05 equals 4.96×10+5, which equals 4.96×100,000 or 496,000. 

Year Pu Pu-238 Pu-239 Sr-89 Sr-90 Sr-89, Sr-90 H-3 Gross Alpha Gross Beta

1945 1.02E+00 3.50E-03 6.05E-02 1.88E-01 3.00E+00

1946 1.02E+00 3.50E-03 6.05E-02 1.88E-01 3.00E+00

1947 1.22E+00 3.50E-03 6.05E-02 1.88E-01 3.00E+00

1948 1.22E+00 3.50E-03 6.05E-02 1.88E-01 3.00E+00

1949 1.22E+00 3.50E-03 6.05E-02 1.88E-01 3.00E+00

1950 2.02E+00 3.50E-03 6.05E-02 1.88E-01 3.00E+00

1951 2.41E+00 3.50E-03 3.05E-02 1.77E-01 3.25E+00 2.45E-03

1952 8.01E-01 3.50E-03 2.05E-02 1.73E-01 5.00E+00 4.11E-03

1953 2.24E-03 3.50E-03 2.05E-02 1.73E-01 5.00E+00 4.97E-03

1954 3.21E-03 3.50E-03 2.05E-02 1.73E-01 5.00E+00 5.42E-03

1955 3.14E-03 3.50E-03 2.05E-02 1.73E-01 5.00E+00 1.06E-01

1956 1.81E-03 3.50E-03 1.89E+00 5.03E-01 5.00E+00 1.07E-01 2.30E-01

1957 1.94E-03 3.50E-03 4.47E-01 2.47E-01 5.00E+00 1.68E-02 2.33E-01

1958 9.16E-02 3.50E-03 2.25E-01 2.01E-01 5.00E+00 9.46E-03 1.65E+00

1959 2.06E-03 3.50E-03 7.25E-02 1.81E-01 5.00E+00 9.84E-03 4.40E+00

1960 4.36E-03 3.50E-03 8.85E-02 1.85E-01 5.00E+00 1.34E-01 1.35E+00

1961 1.07E-02 3.50E-03 3.85E-02 1.75E-01 5.00E+00 7.55E-01 6.05E-01

1962 6.84E-03 1.80E-02 1.00E-03 5.00E+00 1.15E-02 1.22E+00

1963 6.81E-03 1.49E-01 3.98E-02 5.00E+00 2.84E-02 1.28E+00

1964 3.11E-03 6.07E-02 8.87E-02 3.20E+00 5.67E-03 2.67E+00

1965 4.48E-03 4.23E-02 6.18E-02 2.00E+00 7.30E-03 8.13E-01

1966 2.50E-03 2.44E-02 3.56E-02 2.00E+00 4.73E-03 3.98E-01

1967 6.58E-03 5.35E-02 1.34E-02 2.00E+00 1.51E-02 6.86E-01

1968 4.20E-03 3.26E-02 8.20E-04 4.89E-02 5.16E-03 3.26E-01

1969 8.36E-03 5.46E-02 1.31E-02 1.54E-03 4.33E-03 4.19E-01

1970 6.47E-03 1.54E-02 2.24E-02 8.28E-03 6.38E-01

1971 4.24E-03 2.70E-03 6.50E-04 4.68E-03 1.21E-02 2.80E-02 1.16E-02 1.09E+00

1972 7.86E-03 1.10E-03 4.15E-03 6.51E-03 9.60E+00 1.49E-02 3.96E-01

1973 8.60E-03 8.00E-04 4.90E-03 7.50E-03 1.90E+01 1.55E-02 9.99E-01

1974

1975

1976

1977 2.63E-03 1.55E-03 2.29E-03 3.10E-02 3.97E+01

1978 4.36E-03 2.05E-03 2.67E-03 1.05E-02 1.41E+01

1979 1.76E-03 6.37E-04 6.10E-03 1.42E-02 3.31E+01

1980 8.23E-03 1.31E-03 4.10E-02 1.81E-02 4.50E+01

1981 3.35E-03 5.54E-02 4.16E-02 2.37E-02 1.74E+01

1982 3.10E-03 1.68E-02 1.18E-02 1.34E-02 1.53E+01

1983 1.10E-02 4.23E-02 5.68E-02 2.54E-03 1.04E+01

1984 6.19E-03 8.23E-03 2.62E-01 7.03E-03 1.32E+01

1985 3.92E-03 5.83E-03 9.01E-03 1.26E-03 7.02E+01

1986 1.50E-03 3.60E-03 9.20E-03 6.90E-04 2.45E+01

1987 1.40E-03 3.20E-03 6.40E-02 1.00E-03 1.11E+02

1988 1.10E-03 3.20E-03 8.10E-02 2.00E-04 2.62E+01

1989 6.00E-04 2.00E-03 1.80E-02 1.10E-03 4.10E+01

1990 2.00E-04 6.00E-04 2.53E-01 1.20E+01

1991 3.00E-04 1.00E-03 1.24E-01 1.06E+01

1992 3.20E-04 3.90E-04 1.70E-02 1.06E+01

1993 1.08E-03 3.40E-03 2.66E+00

1994 2.80E-03 4.00E-04 3.70E-02 2.23E+00

1995 3.40E-03 6.00E-04 6.00E-04 7.31E-01

1996 2.25E-03 3.90E-04 6.60E-04 6.00E-04 1.02E+00

Table 17-10. Waterborne Radionuclide Releases from LANL (Ci) Based on LANL Compilations a
17-50 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

Table 17-11. Other Waterborne Radionuclide Releases from LANL (Ci) Based on LANL Compilations a

Year Ba-La-140 Ac-227 Cs-137 Am-241 Be-7 Co-57 Co-60 Mn-54 Na-22 Rb-83 Rb-84 Se-75 Sr-85 Y-88 Cs-134 

1945 2.00E-03 1946 2.00E-03 1947 2.00E-03 1948 2.00E-03 1949 2.00E-03 1950 2.00E-03 1951 2.00E-03 1952 2.00E-03 1953 2.00E-03 2.50E+00 1954 2.00E-03 1955 2.00E-03 1956 2.00E-03 1957 2.00E-03 1958 2.00E-03 1959 2.00E-03 1960 2.00E-03 1961 2.00E-03 1962 1963 1964 1965 1966 1967 1.20E-02 1968 1969 1970 1971 1972 1973 2.94E-01 1.50E-03 1974 1975 1976 1977 1.43E-01 2.14E-03 1978 3.18E-01 4.03E-03 1979 1.71E-01 5.27E-03 1980 1.32E-01 5.75E-03 1981 1.23E-01 2.44E-02 1982 2.10E-01 1.88E-02 1983 4.50E-02 3.84E-02 1984 1.97E-02 9.04E-03 1985 5.20E-05 5.54E-03 1986 1.49E-01 3.20E-03 8.31E-01 5.02E-02 3.60E-03 1.89E-02 1.42E-01 1987 8.10E-03 3.60E-03 3.30E-01 8.10E-02 8.50E-03 2.30E-02 8.90E-02 7.90E-02 1988 3.99E-02 3.70E-03 1.60E-02 4.00E-03 9.80E-03 1.90E-02 1989 3.90E-02 4.10E-03 6.90E-02 5.40E-02 6.50E-02 1.43E-01 1.30E-01 2.30E-01 2.60E-02 1.10E-01 1.00E-01 1.90E-03 1990 1.25E-02 2.70E-03 1.19E-02 1.30E-03 5.08E-01 5.30E-02 4.00E-04 1991 6.70E-02 1.10E-03 1.00E-03 0.00E+00 4.50E-02 6.00E-03 6.00E-04 1992 7.80E-03 8.90E-03 1993 8.17E-03 1.12E-02 1994 8.50E-03 3.10E-03 1995 6.60E-03 1.40E-03 1996 2.20E-03 1.99E-03 

a Note regarding scientific notation: 4.96E+05 equals 4.96×10+5, which equals 4.96×100,000 or 496,000.
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-51 

Table 17-12. Priority Indices for Waterborne Radionuclide Releases a

Year Pu Pu-238 Pu-239 Sr-89 Sr-90 H-3 Gross Alpha Gross Beta 

1945 5.12E+10 1.75E+08 7.56E+06 3.75E+08 3.00E+06 

1946 5.12E+10 1.75E+08 7.56E+06 3.75E+08 3.00E+06 

1947 6.12E+10 1.75E+08 7.56E+06 3.75E+08 3.00E+06 

1948 6.12E+10 1.75E+08 7.56E+06 3.75E+08 3.00E+06 

1949 6.12E+10 1.75E+08 7.56E+06 3.75E+08 3.00E+06 

1950 1.01E+11 1.75E+08 7.56E+06 3.75E+08 3.00E+06 

1951 1.20E+11 1.75E+08 3.81E+06 3.53E+08 3.25E+06 1.22E+08 

1952 4.01E+10 1.75E+08 2.56E+06 3.45E+08 5.00E+06 2.06E+08 

1953 1.12E+08 1.75E+08 2.56E+06 3.45E+08 5.00E+06 2.48E+08 

1954 1.61E+08 1.75E+08 2.56E+06 3.45E+08 5.00E+06 2.71E+08 

1955 1.57E+08 1.75E+08 2.56E+06 3.45E+08 5.00E+06 5.30E+09 

1956 9.05E+07 1.75E+08 2.36E+08 1.01E+09 5.00E+06 5.34E+09 2.88E+07 

1957 9.70E+07 1.75E+08 5.58E+07 4.93E+08 5.00E+06 8.41E+08 2.91E+07 

1958 4.58E+09 1.75E+08 2.81E+07 4.03E+08 5.00E+06 4.73E+08 2.06E+08 

1959 1.03E+08 1.75E+08 9.06E+06 3.61E+08 5.00E+06 4.92E+08 5.50E+08 

1960 2.18E+08 1.75E+08 1.11E+07 3.69E+08 5.00E+06 6.69E+09 1.68E+08 

1961 5.35E+08 1.75E+08 4.81E+06 3.49E+08 5.00E+06 3.78E+10 7.57E+07 

1962 3.42E+08 2.25E+06 2.00E+06 5.00E+06 5.74E+08 1.53E+08 

1963 3.41E+08 1.86E+07 7.96E+07 5.00E+06 1.42E+09 1.60E+08 

1964 1.56E+08 7.59E+06 1.77E+08 3.20E+06 2.84E+08 3.34E+08 

1965 2.24E+08 5.29E+06 1.24E+08 2.00E+06 3.65E+08 1.02E+08 

1966 1.25E+08 3.05E+06 7.12E+07 2.00E+06 2.36E+08 4.98E+07 

1967 3.29E+08 6.69E+06 2.68E+07 2.00E+06 7.55E+08 8.58E+07 

1968 2.10E+08 4.08E+06 1.64E+06 2.58E+08 4.08E+07 

1969 4.18E+08 6.83E+06 2.62E+07 2.17E+08 5.24E+07 

1970 3.24E+08 1.92E+06 4.47E+07 4.14E+08 7.98E+07 

1971 2.12E+08 1.35E+08 3.25E+07 5.85E+05 2.42E+07 5.78E+08 1.36E+08 

1972 3.93E+08 5.50E+07 5.19E+05 1.30E+07 7.47E+08 4.95E+07 

1973 4.30E+08 4.00E+07 6.13E+05 1.50E+07 7.75E+08 1.25E+08 

1974 

1975 

1976 

1977 1.31E+08 7.76E+07 2.86E+05 6.19E+07 

1978 2.18E+08 1.03E+08 3.33E+05 2.10E+07 

1979 8.81E+07 3.19E+07 7.63E+05 2.85E+07 

1980 4.12E+08 6.57E+07 5.12E+06 3.62E+07 

1981 1.68E+08 2.77E+09 5.20E+06 4.73E+07 

1982 1.55E+08 8.41E+08 1.48E+06 2.68E+07 

1983 5.52E+08 2.11E+09 7.10E+06 5.08E+06 

1984 3.10E+08 4.12E+08 3.28E+07 1.41E+07 

1985 1.96E+08 2.91E+08 1.13E+06 2.51E+06 

1986 7.50E+07 1.80E+08 1.15E+06 1.38E+06 

1987 7.00E+07 1.60E+08 8.00E+06 2.00E+06 

1988 5.50E+07 1.60E+08 1.01E+07 4.00E+05 

1989 3.00E+07 1.00E+08 2.25E+06 2.20E+06 

1990 1.00E+07 3.00E+07 5.06E+08 

1991 1.50E+07 5.00E+07 2.48E+08 

1992 1.60E+07 1.95E+07 3.40E+07 

1993 5.40E+07 6.80E+06 

1994 1.40E+08 2.00E+07 7.40E+07 

1995 1.70E+08 3.00E+07 1.20E+06 

1996 1.13E+08 1.95E+07 8.25E+04 1.20E+06 

a

 Note regarding scientific notation: 4.96E+05 equals 4.96×10+5, which equals 4.96×100,000 or 496,000.
17-52 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

1.E+121.E+111.E+101.E+091.E+081.E+071.E+061.E+05

19451947194919511953195519571959196119631965196719691971197319751977197919811983198519871989199119931995

Priority Index, L

Plutonium

Gross Alpha Radioactivity

Sr-89

Tritium

Pu-238

Pu-239

Sr-90

Gross Beta 

Radioactivity

1012

10111010

109108107106105

Fig. 17-16. Priority Indices for Waterborne Radionuclide Releases from LANL
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-53 

References 

Andrews LL. Los Alamos National Laboratory site releases up to 1972. Los Alamos Scientific 

Laboratory. ca. 1973. Repos. Nos. 1733, 1734. 

Drake RW, Eyster EH. Memorandum from E.H. Eyster to G.L. Voelz: Uranium dispersed by 

experimental test shots at Los Alamos. 1971. 

Dummer JE, Taschner JC, Courtwright CC. The Bayo Canyon radioactive lanthanum (RaLa) 

program. Los Alamos, NM: Los Alamos National Laboratory; LA-13044-H; 1996. 

Repos. No. 0002. 

Eisele WF. E-mail communication regarding worker autopsy data. 2008. Repos. No. 7874. 

Flack SM, Shonka JJ, Buddenbaum JE. Interview of former LANL employee Bill Moss 

conducted on 26 February 2004. ChemRisk Inc. 2004. Repos. No. 7831. 

Fresquez PR, Mullen A, Ferenbaugh J, Perona R. Radionuclides and Radioactivity in Soils 

Within and Around Los Alamos National Laboratory, 1974 through 1994: 

Concentrations, Trends, and Dose Comparisons. Los Alamos, NM: Los Alamos National 

Laboratory; LA-13149-MS; 1996. Repos. No. 3856. 

Fuehne DP. Personal communication with David P. Fuehne of LANL Meteorology & Air Quality 

Group, 2008. Electronic correspondence summarized by LANL staff. 2008. Repos. No. 

7875. 

Hyatt EC. Total Activity Released from D.P. West Stacks. Memorandum to Dean D Meyer dated 

26 October 1955. Los Alamos Scientific Laboratory. 1955. Repos. No. 0199. 

Hyatt EC. Total alpha activity released from DP West stacks, Bldg. 12 from 1948 through 1955 

(memorandum to Dean D. Meyer). Los Alamos Scientific Laboratory. 1956. Repos. No. 

6601. 

IAEA. Safety Series 49: Radiological surveillance of airborne contaminants in the working 

environment. Vienna, Austria: International Atomic Energy Agency; 1979. 

ICRP. Report of the Task Group on Reference Man. New York, NY: International Commission 

on Radiological Protection; ICRP Publication 23; 1975. 

ICRP. Limits for Intakes of Radionuclides by Workers. Oxford, England: International 

Commission on Radiological Protection; Publication 30, Part 1; 1979. 

Jordan HS, Black RE. Evaluation of the air pollution problem resulting from discharge of a 

radioactive effluent. American Industrial Hygiene Association Journal 19; 1958. 

Kennedy WR, Purtymun WD. Plutonium and Strontium in Soil Near Technical Area 21, Los 

Alamos Scientific Laboratory, Los Alamos, New Mexico Los Alamos, NM: Los Alamos 

Scientific Laboratory; LA-4563; 1971. Repos. No. 2141. 

Krey et al. Remote plutonium contamination and total inventories from Rocky Flats. Health 

Physics 30: 209-214; 1976. 

LAHDRA. Compilation of Excerpts of AEC-789T Forms 1945-1972. 2000. Repos. No. 2001. 

LANL. Death Certificates for LASL/Zia Employees and Los Alamos County Residents; from 

LANL Archives Collection A-1982-007 Box 001. Los Alamos National Laboratory. 

1978. Repos. No. 5597. 

LANL. Environmental Surveillance at Los Alamos During 1980. Los Alamos National 

Laboratory; LA-8810-ENV; 1981. Repos. No. 930. 
17-54 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

LANL. Environmental Surveillance at Los Alamos During 1981. Los Alamos, NM: Los Alamos 

National Laboratory; LA-9349-ENV; 1982. Repos. No. 929. 

LANL. Environmental Surveillance at Los Alamos During 1982 Los Alamos, NM: Los Alamos 

National Laboratory; 1983. Repos. No. 1314. 

LANL. Environmental Surveillance at Los Alamos During 1983. Los Alamos, NM: Los Alamos 

National Laboratory; LA-10100-ENV; 1984. Repos. No. 2342. 

LANL. Environmental Surveillance at Los Alamos During 1984. Los Alamos, NM: Los Alamos 

National Laboratory; LA-104421-ENV; 1985. Repos. No. 654. 

LANL. Environmental Surveillance at Los Alamos During 1985. Los Alamos, NM: Los Alamos 

National Laboratory; LA-10721-ENV; 1986. 

LANL. Environmental Surveillance at the Los Alamos During 1986. Los Alamos, NM: Los 

Alamos National Laboratory; LA-10992-ENV; 1987. 

LANL. Environmental Surveillance at Los Alamos During 1987. Los Alamos, NM: Los Alamos 

National Laboratory; LA-11306-ENV; 1988. 

LANL. Environmental Surveillance at Los Alamos During 1988. Los Alamos, NM: Los Alamos 

National Laboratory; LA-11628-ENV; 1989. 

LANL. Environmental Surveillance at Los Alamos During 1989. Los Alamos, NM: Los Alamos 

National Laboratory; LA-12000-ENV; 1990. Repos. No. 1088. 

LANL. Environmental Surveillance at Los Alamos During 1990. Los Alamos, NM: Los Alamos 

National Laboratory; LA-12271-MS; 1991. Repos. No. 2311. 

LANL. Environmental Surveillance at Los Alamos During 1991. Los Alamos, NM: Los Alamos 

National Laboratory; LA-12572-ENV; 1992. Repos. No. 2189. 

LANL. Environmental Surveillance at Los Alamos During 1992. Los Alamos, NM: Los Alamos 

National Laboratory; LA-12764-ENV; 1993a. Repos. No. 1089. 

LANL. HS & EM Facility Review Record Soil Samples, TA-1 EXC#6308 (ERID 48341) Los 

Alamos National Laboratory. 1993b. Repos. No. 6812. 

LANL. Environmental Surveillance at Los Alamos During 1993. Los Alamos, NM: Los Alamos 

National Laboratory; LA-12973-ENV; 1994. Repos. No. 3903. 

LANL. Environmental Surveillance at Los Alamos During 1994. Los Alamos, NM: Los Alamos 

National Laboratory; LA-12973-ENV; 1995. Repos. No. 3903. 

LANL. Environmental Surveillance at Los Alamos During 1995. Los Alamos, NM: Los Alamos 

National Laboratory; LA-13210-ENV; 1996. Repos. No. 3903. 

LANL. Environmental Surveillance at Los Alamos During 1996. Los Alamos, NM: Los Alamos 

National Laboratory; LA-13343-ENV; 1997. Repos. No. 3860. 

LASL. Memoranda regarding development and testing related to gun-assembled atomic weapons, 

LANL Archives Collection A-1989-092, Folder 13. Memoranda and progress reports. 

Los Alamos Scientific Laboratory. 1944-1945. Repos. Nos. 5403-5418. 

LASL. Chemistry of Uranium and Plutonium. Los Alamos, NM: Los Alamos Scientific 

Laboratory; LA-1017; 1947. Repos. No. 3085. 

LASL. Environmental Monitoring Program - July through December 1970. Los Alamos, NM: 

Los Alamos Scientific Laboratory; LA-4672-MS; 1971. Repos. No. 2178. 

LASL. Environmental Monitoring in the Vicinity of the Los Alamos Scientific Laboratory. Los 

Alamos, NM: Los Alamos Scientific Laboratory; LA-4871-MS; 1972a. Repos. No. 4079. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 17-55 

LASL. Environmental Monitoring in the Vicinity of the Los Alamos Scientific Laboratory - July 

Through December 1971. Los Alamos, NM: Los Alamos Scientific Laboratory; LA4970; 1972b. Repos. No. 2155. 

LASL. Environmental Monitoring in the Vicinity of the Los Alamos Scientific Laboratory. Los 

Alamos, NM: Los Alamos Scientific Laboratory; LA-5184; 1973. Repos. No. 887. 

LASL. Environmental Surveillance at Los Alamos During 1973. Los Alamos, NM: Los Alamos 

National Laboratory; LA-5586; 1974. Repos. No. 2161 

LASL. Environmental Surveillance At Los Alamos During 1974. Los Alamos, NM: Los Alamos 

National Laboratory; LA-5977-PR; 1975. Repos. No. 2133 

LASL. Environmental Surveillance at Los Alamos During 1975. Los Alamos, NM: Los Alamos 

National Laboratory; LA-6321-MS; 1976. Repos. No. 2158 

LASL. Environmental Surveillance at Los Alamos During 1976. Los Alamos, NM: Los Alamos 

National Laboratory; LA-6901-MS; 1977. 

LASL. Environmental Surveillance at Los Alamos During 1977. Los Alamos, NM: Los Alamos 

National Laboratory; LA-7263-MS; 1978. Repos. No. 2069. 

LASL. Environmental Surveilance at Los Alamos During 1978. Los Alamos, NM: Los Alamos 

Scientific Laboratory; LA-7800-ENV; 1979. Repos. No. 953. 

LASL. Environmental Surveillance at Los Alamos During 1979. Los Alamos, NM: Los Alamos 

Scientific Laboratory; LA-8200-ENV; 1980. Repos. No. 2190. 

Maraman WJ, McNeese WD, Stafford RG. Plutonium– health implications for man. Confinement 

facilities for handling plutonium. Health Phys 29: 469-80; 1975. 

McInroy et al. Plutonium in autopsy tissue: A revision and updating of data reported in LA-4875. 

Health Physics 37; 1979. 

McInroy JF. A true measure of exposure, the Human Tissue Analysis Program at Los Alamos. 

Los Alamos Science 23; 1995. 

Miller G, Bertelli L, Guilmette R, McNaughton MW, Eisele WF. A study of early Los Alamos 

internal exposures to plutonium. Radiat Prot Dosimetry 130: 503-9; 2008. 

Miller S. Stack monitoring data from 1973 through 1990. Tabulation and spreadsheet file. Los 

Alamos National Laboratory. 2001. Repos. No. 2744. 

NCRP. Screening Models for Release of Radionuclides to Atmosphere, Surface Water, and 

Ground. Bethesda, MD: National Council on Radiation Protection and Measurements; 

NCRP Report No. 123; 1996. 

O'Brien J., Burmeister R. Prioritization of Airborne Releases, LAHDRA Project Calculation. 

2004. 

O'Brien JM, Burmeister RE. Los Alamos Historical Document Retrieval and Assessment 

(LAHDRA) Project: Task 5 – Prioritization of Releases, Prioritization of Liquid-borne 

Releases. Shonka Research Associates, Inc. 2004. Repos. No. 3925. 

Purtymun WD, Peters RJ, Maes MN. Plutonium depositions and distribution from worldwide 

fallout in Northern New Mexico and Southern Colorado. Los Alamos, NM: Los Alamos 

National Laboratory; LA-11794-MS; 1990. Repos. No. 2821. 

Purtymun WD, Peters RJ, Stoker AK. Radioactivity in Soils and Sediments in and Adjacent to 

the Los Alamos Area, 1974-1977. Los Alamos, NM: Los Alamos Scientific Laboratory; 

LA-8234-MS; 1980. Repos. No. 2174. 
17-56 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 17 

Quinn VE. Analysis of meteorological and radiological data for selected fallout episodes. Health 

Phys 59: 577-92; 1990. 

Schrader B. Radiological Safety Analysis Computer Program, RSAC Version 6.2. Idaho Falls, 

ID: Idaho National Laboratory; 2003. 

Shonka JJ. Analysis of LANL Autopsy Program Results. Calculation SRA-03-003. Shonka 

Research Associates. 2004. Repos. No. 4134. 

Shonka JJ, Mejias NA. Assessment of TA-54 MDA-G Releases of Plutonium from 1981-1991 

Shonka Research Associates. 2006. Repos. No. 7988. 

USDOE. Final environmental impact statement, Los Alamos Scientific Laboratory site, Los 

Alamos, New Mexico. Washington, DC: U.S. Department of Energy; DOE/EIS-0018; 

1979. Repos. No. 688. 

USDOE. DOE Handbook - Airborne Release Fractions/Rates and Respirable Fractions for 

Nonreactor Nuclear Facilities; Volumes I and II. Washington, DC: U.S. Department of 

Energy; DOE-HDBK-3010-94; 1994. 

USEPA. Limiting Values of Radionuclide Intake and Air Concentration and Dose Conversion 

Factors for Inhalation, Submersion, and Ingestion. Washington, DC: United States 

Environmental Protection Agency; Federal Guidance Report No. 11; 1988. 

USNRC. Standards for protection against radiation. Title 10, Code of Federal Regulations, Part 

20; 2003. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 18 18-1

Chapter 18: Screening-Level Evaluation of Airborne 

Plutonium Releases from DP West Site 

Because airborne plutonium releases from DP West Site were documented to have been significantly 

higher than has been officially reported and residential areas were located quite close to the site, a 

screening assessment using the methodology of National Council on Radiation Protection and 

Measurements (NCRP) Report No. 123 (NCRP 1996) was performed for releases from DP West Site 

Building 12 stacks during 1949, the apparent year of peak emissions. The NCRP methodology uses three 

levels of screening calculations for atmospheric transport pathways. Level I screening uses the simplest 

approach and incorporates a high degree of conservatism to avoid underestimating doses to people. Level 

II screening accounts for dispersion in the atmosphere and combines all significant pathways into a single 

screening factor. Level III screening includes more definitive pathways analysis for inhalation, external 

exposure, and ingestion of terrestrial food products in the form of vegetables and/or animal food products. 

The documented release of 86.6 g of 239Pu from the DP West Building 12 stacks during calendar year 

1949 [see Fig. 18-1; (Hyatt 1956)] was converted to a 239Pu release rate using a specific activity value of 

0.063 Ci g-1 (ANL/EVS 2005). This is the approximate value that the LASL investigators used in 1956 to 

convert from measured total alpha activity to the total activity released values, in grams, that were 

reported in the 1956 memorandum. Multiplicative sample line loss and filter burial correction factors of 5 

and 2.33, respectively, were applied based on evaluations conducted by LANL staff (Fuehne 2008). The 

average 239Pu release rate for 1949 was calculated as follows: 

86.6 g × 5.0 × 2.33 × 0.063 Ci g-1 × 3.7x1010 Bq Ci-1 ÷ 3.2x107 s y-1 = 7.35x104 Bq s-1 239Pu

The annual exhaust volume of 1.88x109

 m3 y

-1 for the Building 12 stack [see Fig. 18-2; (Andrews ca. 

1973)] was converted to 58.8 m3 s

-1 to support calculation of the average concentration of plutonium in the 

stacks. 

For the screening-level evaluation of releases from the DP West Building 12 stacks in 1949, the closest 

potentially exposed members of the public were residents at the trailer park located 1 km west of the 

stacks (see Fig. 18-3). Based on the Level I screening method’s assumption that the wind blew toward 

the closest potentially exposed individual 25% of the time, concentrations at that point were estimated as 

one-quarter of the average stack concentration. The exposure point concentration (Bq m-3) was multiplied 

by the all-pathways screening factor (Sv per Bq m-3) from Table 1.1 of NCRP Report No. 123 to yield a 

screening value that was compared to a limiting value. 
18-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 18

Fig. 18-1. Table of corrected annual releases from DP West Building 12 stacks for 1948 through 1955 per Hyatt (1956) 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 18 18-3

Fig. 18-2. Sheet showing exhaust flow volume and (uncorrected) annual releases from DP West Building 

12 Stacks for 1948-1972 (Andrews ca 1973). This handwritten sheet is the most basic documentation 

found of the 1.2-Ci release total that LASL reported in 1979 for operations before 1973. 
18-4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 18

Fig. 18-3. Annotated modern aerial photograph showing former locations of DP West Site Building 12 stacks and nearby residential areas. 

Trailer park drawing is excerpted from USAEC Drawing LA FM 125 (Sheets L7-SW-1 and L6-SE-1). 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 18 18-5

u

f Q B C =

For this screening assessment, the limiting value selected was 1.67×10-4 Sv y-1, which is based on 1 in 

100,000 added risk of fatal or non-fatal cancer using a risk factor of 6.0×10-2 Sv-1 (ICRP 1990). 

It is important to emphasize that the results of the screening calculations are strictly for 

comparison with an environmental standard (limiting value), to determine if compliance with that 

standard is assured or further investigation is warranted. The screening values are not intended to 

represent estimates of actual doses to individuals. 

For Level II screening, the release height was determined to be 58.6 ft above ground level based on 

LASL Drawing 12T35397A2 (See Fig. 18-4). The dimensions of the portion of Building 12 that housed 

the filters and precipitators and faced west was estimated to have been 14.3 m high by 27.9 m wide (see 

Fig. 18-5) based on analysis of Photograph 2284 and a report documenting demolition of the building 

(Christensen et al. 1975). 

The atmospheric concentration at the exposure point was estimated using Equation 1 with f = 0.25, Q = 

7.35×104

 Bq s-1, and u equal to the suggested default value of 2 m s-1. 

 

 (1) 

 

 Where: C = average atmospheric concentration at exposure point, μCi m-3

 f = fraction of time that the wind blew toward the receptor of interest 

 Q = release rate (μCi s-1) 

B = the Gaussian plume model diffusion factor modified for building wake 

effects (from Fig. 1.5 of NCRP Report No. 123) 

u = mean wind speed, m s-1 

The resulting concentration was multiplied by the atmospheric screening factor from Table 1.1 of NCRP 

Report No. 123 to obtain the Level II screening value. In accordance with NCRP recommendations, that 

screening value was compared to 10% of the limiting value in recognition of uncertainties inherent within 

the calculations and associated assumptions. 
18-6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 18

Fig. 18-4. Drawing of DP West Site Building 12 filter house and stacks

Fig. 18-5. Annotated section of Photograph 2284 showing Building 12 from the east 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 18 18-7

Historical documents and interviews with residents of Los Alamos indicate that residents were allowed to 

maintain vegetable gardens after World War II, including at the trailer park west of DP Site, but no 

evidence has been found of production of animal food products within the townsite. The two screening 

values were summed and compared to the screening limit (i.e., the limiting value divided by ten as in 

Level II) to determine whether further evaluation of historical exposures is warranted. In Level III 

screening, the exposure point air concentration from Level II screening was multiplied by a screening 

factor for inhalation and external sources/submersion from Table 1.1 of NCRP Report No. 123 and by a 

second screening factor for vegetable consumption from the same table to obtain screening values for 

inhalation and external exposure as well as for consumption of home grown vegetables. 

Screening Worksheets 

The final 18 pages of this chapter present copies of the applicable worksheet pages by which the NCRP 

Report No. 123 screening method was applied to the DP West Building 12 stack releases. 

Results of the Screening 

The results of preliminary screening of airborne 239Pu releases from DP West site Building 12 stacks 

during 1949 are presented in Table 18-1. In Level I and Level II screening, the screening value exceeded 

the limiting value by at least four orders of magnitude, prompting application of the screening 

methodology at the next highest level. 

The results of the screening calculations are strictly for comparison with an environmental standard 

(limiting value), to determine if compliance with that standard is assured or further investigation is 

warranted. The screening values are not intended to represent estimates of actual doses to individuals. 

The results of Level III screening, which again exceeded the limiting value by over four orders of 

magnitude, indicate that airborne 239Pu releases from Building 12 stacks– as represented by estimated 

releases during 1949– warrant further evaluation by experts in environmental radiological assessment. 
18-8 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 18

Table 18-1. Summary of the preliminary screening of airborne 239Pu releases from DP West Site 

Building 12 stacks during 1949 using the methodology of NCRP Report No. 123 

Level of 

Screening 

Features of Screening 

Methodology 

Screening 

Value 

(Sv y-1) 

Screening 

Limit 

exceeded? 

NCRP Guidance 

I 

Vent air, all pathways, 

concentration at exposure point 

set equal to 25% of stack 

concentration. 

310 Yes Proceed to Level II 

II 

Vent air, all pathways, 

Gaussian plume modeling to 

exposure point outside nearwake region, wind blows 

toward exposure point 25% of 

the time. 

0.37 Yes Proceed to Level III 

III 

Vent air, specific pathways 

(inhalation, external exposure, 

consumption of vegetables), 

same dispersion assumptions 

as Level II. 

0.37 Yes 

"Seek assistance from 

experts in environmental 

radiological assessment" 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 18 18-9

References 

Andrews LL. Los Alamos National Laboratory site releases up to 1972. Los Alamos Scientific 

Laboratory. ca. 1973. Repos. Nos. 1733, 1734. 

ANL/EVS. EVS human health fact sheet, summary radioactive properties for selected radionuclides. 

Lemont, IL: Argonne National Laboratory, Environmental Science Division; 2005. 

Christensen E, Garde R, Valentine A. Demolition of Building 12, an old plutonium filter facility. Los 

Alamos, NM: Los Alamos National Laboratory; LA-5755; 1975. Repos. No. 2349. 

Fuehne DP. Personal communication with David P. Fuehne of LANL Meteorology & Air Quality Group, 

2008. Electronic correspondence summarized by LANL staff. 2008. Repos. No. 7875. 

Hyatt EC. Total alpha activity released from DP West stacks, Bldg. 12 from 1948 through 1955 

(memorandum to Dean D. Meyer). Los Alamos Scientific Laboratory. 1956. Repos. No. 6601. 

ICRP. 1990 Recommendations of the International Commission on Radiological Protection. New York; 

ICRP Publication 60; 1990. 

NCRP. Screening Models for Release of Radionuclides to Atmosphere, Surface Water, and Ground. 

Bethesda, MD: National Council on Radiation Protection and Measurements; NCRP Report No. 

123; 1996. 
18-10 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 18
1-A-1: Radionuclide Pu-239

I-A-2: Release rate, Q 7.4 x 104 Bq s-1

I-A-3: Volumetric flow rate, V 58.8 m

3

 s-1

I-A-4: Exhaust concentration: Ce = Q V -1 1,300 Bq m-3 

(I-A-2)(I-A-3)-1 

I-A-5: Atmospheric concentration: C = 0.25 C e 310 Bq m-3 

0.25 (I-A-4) 

I-A-6: Enter Table 1.1 SF values for the radionuclide 1.0 x 100 Sv per Bq m-3

I-A-7: Screening value: SV = C × SF 310 Sv y-1

(I-A-5) (I-A-6)

I-A-8: Sum results for all radionuclides in I-A-7 310 Sv y-1

I-A-9: Limiting value 1.67x10-4 Sv y-1

I-A-10: Is I-A-8 less than I-A-9? No

 Yes– STOP

 No– Proceed to Section 1.2

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 18 18-11
18-12 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 18
II-bi-1: Radionuclide from I-A-1 Pu-239

II-bi-2: Enter from I-A-4 the calculated concentration in 1,300 Bq m-3 

the exhaust vent, Ce

II-bi-3: Release height, H 17.9 m

II-bi-4: Building height, h b 14.3 m

and building width, h w 27.9 m

II-bi-5: Building surface area: A G = h b h w 399 m2

II-bi-6: Diameter of stack or vent, d 1.3 m

II-bi-7: Wind speed, u 2 m s-1

II-bi-8: Distance from release point to point of exposure, x 1047 m

 Proceed to II-A-1

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 18 18-13
18-14 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 18
II-A-1: Are the point of release and the potentially exposed

individual located as described on the preceding page? No

 Yes– Proceed to Section II-B

 No– Proceed to Section II-A-2

II-A-2 h b (II-bi-4) 14.3 m

2.5 h b = 36 m

H (II-bi-3) 17.9 m

Is H greater than 2.5 h b ? No

 Yes– Proceed to Section II-C

 (no building wakes)

 No– Proceed to Section II-A-3

 (building wakes)

II-A-3: A G (II-bi-5) 399 m2

2.5 A G

1/2 = 50 m

x (II-bi-8) 1047 m

Is x equal to or less than 2.5 A G

1/2 or equal to 

or less than 100 m? No

 Yes– Proceed to Section II-D

 (near wake region)

 No– Proceed to Section II-E

 (outside near-wake region)

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 18 18-15
18-16 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 18
II-E-1: Dispersion factor B from Fig. 1.5 or P from Fig. 1.4 4×10-5 m-2

[see Exhibits G and H]

II-E-2: Radionuclide Pu-239

(II-bi-1)

Release rate, Q 7.35×104 Bq s-1 

(I-A-2)

Wind speed, u 2 m s-1

(II-bi-7)

Atmospheric concentration: 0.37 Bq m-3 

C = 0.25 Q (B or P ) u -1

[0.25 (I-A-2) (II-E-1)] (II-bi-7)-1

Proceed to Section II-F

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 18 18-17
18-18 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 18
II-F-1: Radionuclide from II-bi-1 Pu-239

Atmospheric concentration, C, from 0.37 Bq m-3 

II-B-1, II-B-2, II-C-2, or II-E-2

II-F-2: Atmospheric screening factor, SF , 1 x 100 Sv per Bq m-3

from Table 1.1 for each radionuclide

II-F-3: Calculate screening value: 0.37 Sv y-1

SV = C SF

(II-F-1) (II-F-2)

II-F-4: Sum the results in II-F-3 for all sheets and radionuclides 0.37 Sv y-1

II-F-5: (I-A-9) × 0.1 1.67 x 10-5 Sv y-1

II-F-6: Is II-F-5 greater than II-F-4? No

 Yes– STOP

 No– Proceed to Screening Level III

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 18 18-19
18-20 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 18
III-A-1: Radionuclide from II-F-1 Pu-239

Atmospheric concentration, C, from II-F-1 0.37 Bq m-3 

III-A-2: Screening factor, SF , from Table 1.1 0.55 Sv per Bq m-3

III-A-3: Screening value for inhalation and external exposure

for each radionuclide: SV = C SF 0.20 Sv y-1

(II-A-1) (II-A-2)

Sum of results for all radionuclides and for all sheets 0.20 Sv y-1

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 18 18-21
18-22 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 18
III-B-1: Radionuclide from II-A-1 Pu-239

III-B-2: Can vegetable gardens and/or pastures occur 

at location x (II-A-1)?

`

Yes– For each food category potentially

produced at location x, enter the atmospheric

concentration from III-A-1 in blanks below.

No– Enter zero in blanks below for the

atmospheric concentration for the food

categories not produced at location x and 

go to next step.

Vegetables 0.37 Bq m-3 

Animal food products 0 Bq m-3 

If all the above values are greater

than zero– Proceed to III-B-4

III-B-3: (a) Determine distance to the point of nearest production

for each food category

(b) Return to Section II.

(c) Specify x in II-bi-8 for each food category.

(d) Recalculate atmospheric concentrations for

each food category.

(e) Enter recalculated atmospheric concentration

from either II-C, II-D, or II-E for each

radionuclide and food category in the blanks below.

Vegetables Bq m-3

Animal food products Bq m-3

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 18 18-23
18-24 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 18
III-B-4: Enter radionuclide from III-B-1 Pu-239

Enter atmospheric concentration, C, from either

III-B-2 or III-B-3

Vegetables 0.37 Bq m-3 

Animal food products 0 Bq m-3 

III-B-5: (a) Enter appropriate screening factor, SF , from Table 1.1

Vegetables 0.45 Sv per Bq m-3

Animal food products 0 Sv per Bq m-3

(b) Screening value: SV = C × SF

 (II-B-4) (III-B-5)

Vegetables 0.17 Sv

Animal food products 0 Sv

(c) Sum the results to obtain the total screening

 value from ingestion of radionuclide 0.17 Sv

 Proceed to III-C

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 18 18-25
18-26 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 18
III-C-1: (a) Enter III-A-3: external and inhalation screening value 0.20 Sv

(b) Enter III-B-5: screening value from ingestion 0.17 Sv

(c) Sum external, inhalation, ingestion screening values: 0.37 Sv

[III-C-1(a)] + [III-C-1(b)]

III-C-2: Enter II-F-5: screening limit 1.67 x 10-5 Sv

III-C-3: Is III-C-1( c) less than III-C-2? No

Yes– STOP

No– Seek expert assistance

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 18 18-27
18-28 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 18

This page intentionally left blank 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 19 19-1

Chapter 19: Prioritization of Chemical Releases 

 from LANL 

Operations at LANL have involved many non-radioactive materials, including metals, inorganic 

chemicals, and organic chemicals including solvents. For the sake of simplicity in this report, we will 

refer to these materials as “chemicals”. Prior to the 1970s, uses of chemicals and their ultimate fate were 

poorly tracked and documented compared to radionuclides. One particularly challenging portion of the 

LAHDRA project, for this reason, has been the collection of information concerning historical uses of 

chemicals, identification of those that were most likely released off site, and determination of which 

chemicals have been most important in terms of potential off-site health hazards. 

Sources of Information Regarding Historical Chemical Usage 

The sources of information about chemical usage at LANL that have been most useful to the LAHDRA 

team include a modern-day chemical inventory, historical chemical inventories, and various types of 

LANL site documents. 

Current Chemical Inventory 

LANL maintains an inventory of chemicals present on-site 

to comply with annual environmental reporting requirements 

for hazardous chemical emissions. Information on the 

quantities and types of chemicals used at LANL was 

collected starting in 1991 and a Microsoft Access® database 

was completed in 1993 (ESH 1999). The initial tracking 

system called the Automated Chemical Inventory System 

(ACIS) had been updated annually since 1994. Recently, the 

inventory system was changed to the Injury Illness and 

Chemical Management Online Application by E3. Although 

the project team was granted access and training for the new 

system, the initial analysis of chemical inventory data 

conducted in 2000 was not repeated due to the limited 

usefulness of recent chemical inventory data for evaluating historical emissions of chemicals from LANL. 

Fig. 19-1. Personnel involved in early 

explosives testing at Los Alamos. 
19-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 19

The ACIS database includes the following fields: 

• Chemical name, CAS number, and bar code 

• Location of chemical (technical area, building) 

• Quantity, units of measure, and physical state (solid, liquid, gas) 

ACIS is available on the internal LANL Web site using a SecureID card. Access to the database allows 

the data to be compiled in different ways, and provides details such as the specific locations of chemicals 

through database search capabilities. A paper copy of the ACIS Microsoft Access® database file was 

provided to the project team by the ESH-5 group on January 26, 1999. At that time, the database 

contained approximately 120,000 records. Subsequently, access through a Web interface was granted to 

allow limited searches to be performed. A request for an official-use-only copy of the database for 

performing more complex searches was granted. However, the database does not include radionuclides, 

explosives, beryllium, depleted uranium, or other bulk metals. It contains many trade name products with 

no information on whether they include any hazardous materials. The database also does not include any 

information regarding how the chemicals are used or their potential for release to the environment. 

Preliminary review of the ACIS database indicates that 37 chemicals were each present onsite at 250 or 

more individual locations and therefore represented the largest onsite quantities. Twelve of the thirteen 

chemicals present onsite in the highest quantities do not have USEPA recommended toxicity values for 

potential cancer and non-cancer systemic health effects, although some can be irritants or corrosives at 

high concentrations. The 37 high quantity chemicals selected from ACIS are shown in Table 19-1 in 

order of decreasing estimated on-site quantities. 

Of the 37 high quantity chemicals, the 13 with USEPA recommended toxicity values are shown in Table 

19-1 ranked in order of generic toxicity, “1” being more toxic than “13”. Generic toxicity includes both 

cancer and non-cancer chronic health effects with no bias toward any route of potential exposure (e.g., 

inhalation, ingestion, and dermal contact) or to any potential environmental exposure medium (e.g., air, 

soil, water, food products) since little is known about how the chemicals were used and the potential for 

off-site release. 

LANL personnel suggested that site files of Material Safety Data Sheets could be reviewed for the trade 

name products to determine if the trade name products contain any hazardous materials. An analysis of 

the remaining inventory chemicals not included in Table 19-1 for quantity and location of use information 

could be conducted in future phases of the dose reconstruction to further prioritize recent chemical use at 

LANL. For chemicals that could be released to the off-site environment as a result of their use, air 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 19 19-3

Table 19-1. Selected Data from a Current LANL Chemical Inventory 

Chemical Onsite Quantity Toxicity Ranking 

Nitrogen 4.2 x 107 L -- 

Argon 3.8 x 107 L -- 

Helium 3.7 x 107 L -- 

Hydrogen 1.6 x 106 L -- 

Oxygen 1.6 x 106 L -- 

Propane 1.3 x 105 L -- 

Sulfuric acid 2.2 x 104 L -- 

Toluene 2.1 x 104 L 8 

Sodium hydroxide 1.5 x 104 kg -- 

Sodium chloride 8.6 x 103 kg -- 

Ethyl alcohol 7.1 x 103 L -- 

Sodium carbonate 6.8 x 103 kg -- 

Hydrochloric acid 6.6 x 103 L -- 

Acetone 6.2 x 103 L 7 

Ethylene glycol 5.1 x 103 L 12 

Chlorodifluoromethane 4.8 x 103 L 14 

Methyl alcohol 2.8 x 103 L 10 

Nitric acid 2.6 x 103 L -- 

Isopropanol 2.2 x 103 L -- 

Hydrogen peroxide 7.8 x 102 L -- 

Buffer solutions 6.3 x 102 L -- 

Acetic acid 5.8 x 102 L -- 

Hexane 5.4 x 102 L 5 

Methylene chloride 4.9 x 102 L 4 

Miscellaneous chlorofluorcarbon 4.6 x 102 L -- 

1,1,1,2-Tetrafluoroethane 4.4 x 102 L -- 

Photographic developer products 3.9 x 102 L -- 

Dimethyl sulfoxide 3.8 x 102 L -- 

Chloroform 3.4 x 102 L 1 

Benzene 2.1 x 102 L 2 

Ether 2.0 x 102 L 9 

Dichlorodifluoromethane 1.5 x 102 L 6 

Photographic fixer products 1.2 x 102 L -- 

Tetrahydrofuran 6.0 x 101 L 3 

Ethylenediamine tetraacetic acid 3.8 x 101 kg -- 

Ethyl acetate 2.1 x 101 L 11 

1,1-Difluoroethane 8.5 x 100 L 13 
19-4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 19

dispersion and other transport models and exposure models can be used to estimate an onsite threshold 

quantity that would not result in adverse health impacts to off-site populations using site-specific 

assumptions regarding dispersion, transport and exposure. The threshold quantity approach could be used 

to focus data gathering efforts on those chemicals for which the on-site inventory quantity exceeds the 

threshold quantity. However, the chemical inventory database only contains information on selected 

chemicals present at LANL since 1991. 

Historical Chemical Inventories 

Harry Schulte, a former Industrial Hygiene group leader, is reported to have conducted a chemical 

inventory in the early 1970s (ESH 1999). A draft report was prepared, but was never finalized. It was 

suggested that the draft report and supporting data might be located in the Industrial Hygiene group files 

in the Central Records Center. Surviving members of Mr. Schulte’s group reportedly do not have any 

copies in their possession. This 1970s chemical inventory information has not been located by the project 

team. 

For years prior to the initiation of the current chemical inventory program, the project team identified 

several lists of chemicals used at LANL in years prior to 1980s environmental reporting requirements. 

The lists represent the years 1947-50 (Repos. No. 296), 1971 (Repos. Nos. 756, 883, 997), and 1970s 

(Repos. Nos. 279, 284, 1380, 2015). Quantities and locations of use are typically not provided in these 

lists. The project team identified considerable documentation related to chemical use in specific areas for 

the 1980s and 1990s as LANL began collecting these data in response to regulatory requirements. 

Table 19-2 is a list of chemicals documented as having been used at LANL at some point in time. This 

list was compiled from the LANL documents that have been reviewed to date, entered into the project 

database, and released to the public. Copies of many of the reviewed documents have not yet been 

obtained by the project team from LANL as of the preparation of this report. Classification, privacy act, 

and legal privilege reviews are required prior to public release. Documents used to identify the 

chemicals in Table 19-2 are included in the reference section and are described below.
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 19 19-5

Table 19-2. Chemicals Historically Used at LANL 

Elements 

aluminum 

antimony 

arsenic 

barium 

beryllium 

bromine 

cadmium 

chromium 

copper 

dioxane 

fluoride 

gallium 

iron 

lanthanum 

lead 

lithium 

manganese 

mercury 

molybdenum 

nickel 

niobium 

platinum 

samarium 

silver 

tantalum 

thallium 

uranium (normal and depleted) 

vanadium 

zinc 

zirconium 

Volatile Organic Compounds 

acetone 

benzene 

carbon tetrachloride 

chloroform 

chlorodifluoromethane 

dichlorodifluoromethane 

difluoroethane 

ethanol 

ether 

isopropanol 

kerosene 

methanol 

methyl chloride (chloromethane) 

methyl ethyl ketone (2-butanone) 

methylene chloride (dichloromethane) 

tetrachloroethylene 

tetrabromoethane 

tetrahydrofuran 

toluene (toluol) 

trichloroethane 

trichloroethylene 

xylene 

Inorganics 

asbestos (magnesium silicate) 

bromide 

cyanide 

hydrochloric acid 

hydrofluoric acid 

nitric acid 

oxalic acid/ oxalate 

perchloric acid/ perchlorate 

phosphoric acid 

sodium hydroxide 

sodium thiosulfate 

sulfuric acid 

Semi-Volatile Organics 

n-butyl acetate 

ethyl acetate 

ethylene glycol 

hexachlorobutadiene 

naphthalene 

PCB (polychlorinated biphenyls): Aroclor 1242 

Explosives 

Baratol (mixture of barium nitrate and TNT) 

Comp. B (mixture of 60% RDX and 40% TNT) 

Cyclotol (mixture of 70-75% RDX and 25-30% TNT) 

Explosive D (ammonium picrate; ammonium1,3,5-trinitrophenol) 

HMX 

(octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) 

nitrobenzene 

nitrocellulose 

nitromethane 

NQ (nitroguanidine; Picrite) 

Octol (mixture of 70-75% HMX and 25-30% TNT) 

PBX 

Pentolite 

PETN (pentaerythritol tetranitrate) 

picric acid 

PTX-2 (2,6-bis-picrylamino-3,5-dinitropyridine) 

RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) 

Saltex 

TATB (1,3,5-triamino-2,4,6-trinitrobenzene) 

Tetryl (1,3,5-trinitrophenyl-methylnitramine) 

TNT (2,4,6-trinitrotoluene) 

Torpex 
19-6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 19

Table 19-3 is a compilation of data located by the project team regarding quantities of chemicals used or 

released historically from LANL. Five documents report quantities of primarily volatile organic solvents 

that were used at LANL from 1971 until 1985. Three documents identify chemical quantities as “released 

or lost to the atmosphere”. One of the three documents, Repos. No. 1197, is a third source of the same 

numbers provided in Repos. Nos. 610 and 1324. It states that the amount of airborne solvents is taken 

from LASL stock issue records. However, it is often reasoned that all of the volatile solvents will in time 

become airborne no matter what the disposal method. Therefore, it appears that 100% volatilization was 

assumed. The chemicals listed in Table 19-3 are in the order of quantity used or released. Selection of 

the chemicals addressed in these documents was based on State and Federal air pollution requirements at 

the time of reporting. From Table 19-3, it can be concluded that trichloroethane and trichloroethylene 

were the most used volatile organic chemicals at LANL in the early 1970s. However, trichlorethylene 

appears to have been replaced by Freons in the early 1980s. Methyl ethyl ketone was also used in high 

quantities until 1982. 

Site Documents 

In the late 1980s, the Senate Committee on Armed Services asked the Office of Technology Assessment 

to evaluate what was known about the contamination and public health problems at the Nuclear Weapons 

Complex (U.S. Congress 1991). Contaminated sites and initial cleanup activities at LANL were 

described in this report. A summary of hazardous substances released to the environment at LANL 

formed the basis for our initial list. 

For each of the over 600 solid waste management units (SWMUs) identified in the 1990 Solid Waste 

Management Units Report (LANL 1990), the unit, waste and releases information sections were reviewed 

by the project team to identify additional chemicals that may have been released from LANL. 

An additional 480 SWMUs were added by the EPA in 1994, and another 1,000 Potential Release Sites 

(PRSs) were included in the investigation by the Department of Energy, for a total of 2,120 areas of 

concern. The 1996 Baseline Environmental Management Report (USDOE 1996) describes historical 

activities at the potential release sites involving: asbestos, barium, lead, depleted uranium, beryllium, and 

PCBs. High explosives, organic solvents, and ordnance are also cited but specific chemical names are not 

provided. 
1971 

1

1972-73 (12 mo.) 

2

1972 

3

1973 

3

1974 

3

1975 

3

1976 

3

1977 

3

1978 

3

1978 

4

1979 

3

1980 

5

1981 

CHEMICAL (kg released) (kg issued) (kg used) (kg used) (kg used) (kg used) (kg used) (kg used) (kg used) (kg losses) (kg used) (kg used) (kg us

ORGANICS

Methyl chloroform (trichloroethane) 26,571 19,138 25,600 18,300 25,800 22,900 34,000 28,300 24,100 13,741 23,800 28,200 39

C Trichloroethylene 27,719 17,007 20,400 15,500 16,200 9,400 13,200 10,200 7,400 2,041 6,900 3,400 3

Acetone 15,610 -- 18,800 9,200 12,400 16,100 15,500 12,700 10,600 2,721 8,300 7,900 10

Freons 16,825 6,531 10,900 13,300 15,000 10,200 12,400 13,800 8,200 3,265 9,200 12,800 12

C Perchloroethylene 10,540 680 3,400 680 1,000 820 680 1,000 1,400 -- 340 1,400 9

Kerosene 7,338 -- 8,100 5,000 5,900 4,800 4,600 4,400 3,800 -- 4,100 5,800 5

Methyl ethyl ketone -- -- -- -- -- 2,300 9,400 10,600 14,300 3,537 22,000 11,400 21

Ethanol -- -- -- -- -- -- 1,088 9,200 10,900 -- 9,900 9,400 11

Toluene 2,063 -- 2,300 2,100 1,200 2,700 3,300 1,600 2,100 -- 2,100 650 

n-Butyl acetate -- -- -- -- -- 3,311 5,170 2,222 10 -- -- -- 

Ethyl acetate -- -- -- -- -- -- 104 2,404 180 1,633 -- -- 

Methanol 1,125 -- 590 540 1,500 1,700 6,600 4,300 2,600 -- 3,300 2,400 3

C Methylene chloride 1,669 -- 820 820 310 1,000 820 2,200 250 771 170 180 

Isopropanol -- -- -- -- -- -- 218 952 950 -- -- -- 

n-Hexane -- -- -- -- -- 209 304 290 210 -- -- -- 

C Chloroform 3,088 -- 360 250 500 380 370 190 160 -- 200 310 

C Carbon tetrachloride 558 -- 300 290 250 100 250 230 200 -- 280 100 

Xylene -- -- -- -- -- -- 86 227 290 -- -- -- 

C Benzene -- -- 181 127 110 45 141 32 40 -- -- -- 

Tetrahydrofuran -- -- -- -- -- -- -- -- -- -- -- -- 

C Dioxane -- -- -- -- -- -- 14 32 15 -- -- -- 

INORGANICS

C Cadmium 1.E-02 -- -- -- -- -- -- -- -- -- -- -- 

C Beryllium 3.E-05 -- -- -- -- -- -- -- -- -- -- -- 

Mercury -- -- -- -- -- -- 500 290 180 -- 140 140 

ACIDS --

Nitric acid 20,200 -- -- -- -- -- -- -- 80,000 -- 58,100 71,900 99

GASES

Helium -- -- -- -- -- -- -- -- -- 6800-13,600 -- -- 

Sulfur hexafluoride 6,812 -- 17,400 6,700 10,300 11,400 12,200 13,700 9,200 8,209 11,400 6,900 10

-- Not reported.

C known or suspected human carcinogen

1

 1971 Pollutant Inventory. Releases estimated by group leaders using chemical stock issue records. (Rep. No. 756 / 997). 

2 

 Response to Sept. 6 TWX Concerning Use of Trichloroethylene. H-5 Division. September 14, 1973. (Rep. No. 2816). 

3 

 Attachment II to Air Quality Regulation Review #3: NAAQS. Chemical and gas usage. June 9, 1980. (Rep. No. 610); 

 

 Volatile and/or dangerous chemicals checked out of the storeroom (Rep. No. 1324);

 Airborne effluents 1973: airborne releases, nonradioactive 1972-73 (Rep. No. 1197).

4 

 Atmospheric Emissions of Non-Radioactive Materials. Losses estimated by LASL groups using >1500 lb/yr. January 17, 1979. (Rep. No. 610). 

5 

 Attachment I to Nitric Acid and NOx Emissions. November 30, 1982. (Rep. No. 511). 

6 

 Table G-12, p. 140, of the HSE-8 Annual Report. Attachment to Chlorinated Hydrocarbon Solvents. December 2, 1986. (Rep. No. 280). 

Table 19-3: Reported Quantities of Chemicals Historically Used or Released at LANL

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 19 
19-8 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 19

The project team has been following Environmental Restoration (ER) activities at LANL since the project 

began in early 1999. Numerous press releases and fact sheets regarding environmental investigations and 

surveillance activities have been provided by the ER Project and have supplied some relevant 

information. For example, oxalic acid was used to purify uranium and plutonium in early operations at 

TA-1 and TA-21. Oxalate has been detected in a groundwater monitoring well in Lower Los Alamos 

Canyon (LANL 1998). Recently, perchlorate was detected in a groundwater monitoring well in 

Mortandad Canyon, in a water supply well in lower Pueblo Canyon, and in the CMR Building ductwork 

(LANL 2000). Perchloric acid is used in high-explosive (HE) formulation (Dobratz 1995) and in nuclear 

chemistry analyses conducted in CMR Building.

Explosives including HMX, RDX, and TNT that have been detected in a groundwater monitoring well at 

TA-16 (S Site) and at Material Disposal Area-P reflect machining and subsequent disposal activities that 

occurred at TA-16, the center for research in high explosives since the 1940s. Prior to the construction of 

the High-Explosives Wastewater Treatment Facility at TA-16 in the 1990s, over 12 million gallons of 

water per year were used to keep the surface of high explosives cool and wet while machining. Following 

settling of the solids and heavier materials, the remaining water was discharged to the environment via 

outfalls. The wet solids were trucked to a burning ground, separated from liquids with a sand filter, then 

dried and ignited. The filtrate was treated before being discharged. Solvents such as acetone, methanol 

and ethanol were released to the atmosphere by volatilization from the water discharged at the outfalls 

(LANL 1998, 1999). 

Detonable quantities of explosives have been removed from MDA-P during RCRA clean-closure 

excavation activities (Santa Fe New Mexican 1999). A document located on microfiche in the Central 

Records Center at LANL (author and date unknown; Repos. No. 672) states that quantities of explosives 

burned at TAs-14, 15, 16, 36, and 40 range from 100-300 lb/yr at TAs-14 and 33, to 96,300 lb/yr at TA16. Normal uranium, HE-contaminated solvents (unidentified) and other combustibles are also disposed 

of by burning at these locations. 

Project team review of X-Division Progress Reports from 1944 through 1945 has yielded reported 

estimates of quantities of high explosives used during that time period. These data are presented in Table 

19-4. 
Table 19-4: Reported Quantities of High Explosives Used per Month (lbs)

DATE > Aug-44 Sep-44 Oct-44 Nov-44 Dec-44 Jan-45 Feb-45 Mar-45 Apr-45 May-45 Jun-45 Jul-45 Aug-45 S

EXPLOSIVE

Barium Nitrate 3,250 3,170 19,850 42,750 35,000 57,500 60,000 

Composition B 23,523 27,600 47,150 80,850 

Composition B-1 6,800 5,366 7,510

Composition B-2 3,900 20,600 87,500 90,250 66,850

TNT 650 131 1,250 2,935 2,475 7,500 9,200 12,800 20,400 20,150 

Aluminum-TNT 60/40 937 1,008 1,390 1,750 200

Torpex

 1

1,100 1,250 6,953

Saltex 463

Pentolite 500 0

Cyclotol 70/30 250

PTX 150 100 150

RDX 6

Sum 7,900 7,729 18,494 25,710 35,293 54,435 109,950 72,750 135,450 168,250 147,150 

Reported TOTAL 8,900 12,434 18,494 -- 23,523 34,793 54,185 109,950 72,550 135,300 168,150 147,000 

Waste (lbs) 1,200 1,518 2,160

Rejected Castings 

Source: X-Division Progress Reports 1944-47 (Rep. Nos. 2931, 2915, 2916, 2917, 2918, 2919, 2920, 2921, 2936, 2935, 3128, 3

1

 Torpex is 5:1 Comp B :TNT

-- Quantities of explosives used are not reported in the monthly X-Division Progress Report for November 1944. 

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 19 
19-10 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 19

A 1981 memorandum from R. W. Ferenbaugh to H. S. Jordan dated January 27, 1981 states that 20,000 – 

30,000 kg (91,000 – 136,000 lbs) per year of waste explosives were disposed of at TA-16 by open 

burning. Explosive burning experiments conducted at LASL several years prior to 1981 estimated annual 

emissions of 600-800 kg of NOx, 100-200 kg of carbon monoxide, and 300-500 kg of unidentified 

particulates from this open burning process (Ferenbaugh 1981; Repos. No. 611). 

An effluent material summary for group GMX-7 (Drake 1971; Repos. No. 2114) includes several 

explosives dispersed at TA-40 as gaseous detonation products during the period July – September 1971 

(Table 19-5). Toxic material reports for December 1979 through September 1980 (Dinegar 1980; Repos. 

No. 2112) report the approximate amounts of HE exploded per month in WX-7 shots at TA-40 and TA22. 

Fig. 19-2. LANL workers watch an explosive test in the distance 

Table 19-5. Reported Quantities of Explosives Dispersed 

Explosive 

July – 

Sept 1971 

Dec 

1979 

(kg) 

Jan 

1980 

(kg) 

Feb 

1980 

(kg) 

Mar 

1980 

(kg) 

Apr 

1980 

(kg) 

May 

1980 

(kg) 

June 

1980 

(kg) 

July 

1980 

(kg) 

Aug 

1980 

(kg) 

Sept 

1980 

(kg) 

Nitromethane 450 kg 

(990 lb) -- -- -- -- -- -- -- -- -- -- 

Comp B 34 kg 

(75 lb) 0.1 3.1 10.8 22.4 13.2 6.7 19.6 -- 52.8 9.6 

Baratol -- 0.1 2.9 17.1 63.7 21.1 16.4 25 -- 89 3.4 

TATB -- 0.4 0.7 0.25 0.1 0.4 0.4 0.03 0.6 0.7 0.7 

TNT -- -- -- 2.7 5.4 13.5 2.7 5.4 -- 25 2.7 

Octol -- -- 12 6 3 -- 6 3 -- 6 -- 

PETN 7 kg 

(15 lb) 0.02 0.09 0.06 0.05 0.1 0.01 0.13 0.03 0.05 1.2 

PBX 0.9 kg 0.1 0.4 0.4 0.3 0.4 0.3 0.05 0.4 0.3 0.5 

Tetryl 0.05 kg -- -- -- -- -- -- -- -- -- -- 

TOTAL 492 kg 1 kg 19 kg 37 kg 44 kg 49 kg 32 kg 54 kg 1 kg 174 kg 18 kg 

 -- not reported 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 19 19-11

Research, development, and testing of high explosives were conducted at more than 25 different 

Technical Areas of LANL (Goldie 1984; Repos. No. 658). Many new formulations of the conventional 

explosives HMX, RDX and TNT were synthesized and tested at LANL since the 1940s (Dobratz 1995). 

Other high explosives such as Baratol, Comp B, Pentolite, Torpex, and Tetryl were tested at the firing site 

at TA-14 (IT Corporation 1989; Repos. No. 2192). 

Uranium and other metals such as lead, beryllium, aluminum and cadmium (HAI 1993; Johnson and Dahl 

1977; Repos. No. 2249) were released to the environment as a result of test shots conducted at LANL 

since the 1940s. Drake and Eyster (1971; Repos. No. 1412) estimate that between 75,000 and 95,000 kg 

of uranium has been expended in experimental shots at LANL from 1949-1970. Normal uranium was 

used until 1954, then depleted uranium was used exclusively. The estimate does not address where the 

uranium went, only that they don’t have it any longer. A 1952 AEC report states that test shots at LASL 

routinely dispersed 300 lbs of uranium per month and 200 lbs of barium per month (English 1952). Two 

1971 memoranda (Drake 1971; Repos. No. 2114) report toxic materials dispersed by GMX Division shots 

for April and May 1971 as shown in Table 19-6. 

Table 19-6. Materials Dispersed by GMX Division Shots for April and May 1971 

Toxic Material April 1971 May 1971 

Uranium-238 171 kg (376 lb) 142 kg (312 lb) 

Beryllium 0.7 kg 3 kg 

Tritium 125 cm3 STP 208 cm3 STP 

Lead 0.042 kg 0.8 kg 

Bromine 0.165 kg -- 

-- not reported 

Most of the documents describing PCBs at LANL that have been identified by the project team to date are 

logbooks of analytical results with unidentified sampling locations. Several documents describe storage 

and disposal of PCB wastes at TAs-21 and 54 (Santa Fe Engineering 1995; Repos. No. 1262). PCB 

cleanups were conducted at TAs-3, 53, and near groundwater production wells in the mid 1980s and 

1990s as a result of leaking transformers and capacitors (Unknown 1997 [Repos. No. 1094]; LANL 1993 

[Repos. No. 1269]). Aroclor-1242 was used as a coolant in CMB-11 division in 1961 (Enders 1969; 

Repos No. 1409). 

A 1973 document, “Summary of wastes and effluents for Omega Site TA-2”, estimates that 1.4 lb d-1 of 

hexavalent chromium were released to the air in cooling tower effluent. The Omega West Reactor 

(OWR) primary water was cooled via a 5 MW evaporative cooling tower. Trichloro-s-triazinetrione 
19-12 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 19

(C3N3O3Cl3), a common microbicide, was added to the secondary-side water in the tower to control algae 

growth. A second product containing polyacrylate polymer, polyoxylated aliphatic diamine, and 

tolyltriazole was added to control scale and corrosion. Cooling tower water was discharged to the 

environment via entrainment in the exhaust air stream and through discharges of blowdown water to Los 

Alamos Canyon Creek. These blowdown discharges were another measure used to control scale and 

corrosion in the secondary (sump) water by eliminating solids. Repos. No. 645 reports that these 

discharges totaled approximately 60,000 gallons per week in 1973. Another 300 gallons per week of 

blowdown water came from the heat exchanger for the primary water in the OWR’s demineralizer loop. 

Like the main OWR exchanger, the cooling water for this heat exchanger came from the municipal water 

supply. 

Repos. No. 645 also reports the exhaust air stream from the OWR cooling tower included entrained 

secondary water that was discharged to the environment at a rate of 3.9 gal min-1. The document states 

this resulted in the discharge of 20 lb of sulfuric acid and 1.4 lb of hexavalent chromium to the 

atmosphere per 24 h period. 

Draft Comprehensive Environmental Assessment and Response Program (CEARP) documents from 1986 

(Repos. No. 525) report a staff member recalling the use of potassium dichromate in the cooling tower 

water prior to a time when the heat exchanger components were changed from aluminum to steel. CEARP 

was the Department of Energy’s Superfund program for Federal Facilities in the 1980s. The employee 

stated that mist from the tower would drift about the site and turn things green. This “greening” effect 

went away with the switch to steel components (and the subsequent reduction in use of potassium 

dichromate). The use of potassium dichromate as a corrosion inhibitor is confirmed in Repos. No. 645, 

which states that the blowdown discharges from the cooling tower (∼60,000 gal per week) included 

approximately 14.5 pounds of hexavalent chromium. This same document reports that the blowdown 

also included 3 lb of chlorophenol biocide and 200 lb of sulfuric acid in the form of sulfate salts (used for 

pH control). The blowdown from the demineralizer loop heat exchanger contributed another 20 lb of 

sulfuric acid and 0.5 lb of chlorophenol biocide. Repos. No. 645 also says it was planned to make the 

switch from aluminum to stainless steel components in fiscal year 1974 to reduce to amount of corrosion 

inhibitor required and thus reduce the amount of hexavalent chromium in the blowdown water. 

An inventory of pollutant releases to the environment for 1971 (Repos. No. 883) states that use of 

chromates will be discontinued once the aluminum heat exchanger is replaced with a stainless steel unit. 

This same document reports the average concentration of hexavalent chromium in the TA-2 blowdown to 

be 25 mg L-1, which was 2,500 times the quality standard of 0.01 mg L-1 for that era. The same effluent 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 19 19-13

stream is reported to contain total dissolved solids at an average concentration of 800 mg/l, which also 

exceeded the applicable quality standard of 500 mg L-1. 

The Water Boiler’s cooling tower used potassium dichromate by the hundreds of pounds; waterborne 

effluent ran down the nearby creek, and sometimes chromium “rained from the sky,” and windshields on 

people’s cars had to be replaced (G. Neely, 1999 personal communication). Condensate poured on the 

ground; there was a tree in the area with Cs-137 in its leaves as a result. There was reportedly also 

asbestos in some TA-2 buildings. 

Repos. No. 2211 reports that a “very serious” mercury spill took place at the Clementine site on 

December 31, 1948 that required a “prolonged period” of cleanup. This report also mentions that routine 

monitoring for mercury vapor had been going on at the Clementine site prior to this incident. 

Repos. No. 2201 reports that a mercury spill occurred at the Clementine site between January 20, 1951 

and February 20, 1951. Air samples were collected and analyzed for mercury vapor and urine samples 

were collected from three exposed workers. The report states that “the results obtained showed all 

exposures below hazardous levels.” 

In late 1952, it was reported that members of H Division had been participating in conferences relative to 

the large quantity of contaminated mercury to be pumped from the fast reactor at Omega Site. Since the 

material was contaminated with plutonium, it appeared to the participants that the plutonium hazard was 

more serious than that of the mercury vapor [Repos. No. 124]. 

Perchlorate was identified in shallow groundwater in Mortandad Canyon at concentrations ranging from 

80 to 220 ppb. Perchlorate was also found in groundwater characterization wells at 12 ppb and in drinking 

water supply wells at 2 to 3 ppb, just above analytical detection limits. It is assumed that the perchlorate 

contamination was discharged in effluent from the TA-50 Radioactive Liquid Waste Treatment Facility, 

and also from legacy waste that was discharged into Acid Canyon from the TA-45 treatment plant which 

operated from 1943 to 1964. 

In August 2002, benzene was identified in soil at TA-48 from historical solvent use. 

Accident/ incident files from the Health Divisions were identified for 1944-1991 (Repos. Nos. 3461-

3496). However, the files primarily document chemical spills and indoor exposures to workers. 

Operations related to the presence of the chemical are not described. The documentation of a few 

incidents that could have resulted in releases to the off-site environment was extracted and entered into 

the project database. A document titled “Chronological Record of Accidents at LASL” lists a fatality due 
19-14 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 19

to asphyxiation by methyl chloroform at “New” Sigma Building on February 14, 1961 (Unknown 1979; 

Repos. No. 514). Details of the accident are not provided. 

Many of the Health/ Industrial Hygiene Division reports and correspondence files include memoranda 

regarding the presence of numerous solvents, metals, and acids in various LANL divisions. However, 

details regarding building locations, quantities used, or the operations involved are rarely provided. The 

chemicals mentioned are included in Table 13-1. 

Preliminary Prioritization for Chemicals 

USEPA Region 9 Preliminary Remediation Goals (PRGs) are target cleanup levels based on conservative 

assumptions regarding direct exposure to soil through ingestion, dermal contact and inhalation, and direct 

inhalation of vapors and particulates (USEPA 2002). PRGs are based on cancer as an endpoint if 

available cancer potency factors (“slope factors”) result in a more conservative (lower) PRG than would 

result based solely on evaluation of non-cancer health effects. 

As a first step towards prioritization of potential chemical releases, PRGs for chemicals used and possibly 

released historically from LANL were used by the LAHDRA team to rank the potential of various 

chemicals to result in adverse health effects to off-site populations. The lower a PRG, the higher the 

potential for off-site health effects if the compound were released beyond the site boundary– this 

preliminary ranking does not address actual quantities released or whether real exposures occurred; 

however, these factors will be considered as the prioritization process advances. 

PRGs for soil were used to rank chemicals usually present in the environment as particulates, and PRGs 

for air were used to rank volatile chemicals. Both soil and air PRGs were considered for explosives. 

Toxicity factors are not available for some chemicals used at LANL, and estimates of quantities used 

have been identified through systematic document review for only a subset of those chemicals with 

published toxicity factors. Estimates of quantities of a material used on an annual basis are in some cases 

available. “Annual use” is typically the highest known annual usage of a compound from available data, 

and in some cases may be based on a single year for which data are available. Reported values are often 

presented as quantities used, issued, lost, or released, and it is not always clear how the quantities were 

determined. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 19 19-15

Table 19-7 shows a ranking of Los Alamos chemicals based on PRGs for soil, while Table 19-8 presents 

a ranking based on PRGs for air. Table 19-9 presents a ranking method that takes into account estimates 

of annual usage and U.S. EPA toxicity values such as slope factors and RfDs. Oral slope factors are used 

to indicate the strength of the chemical’s ability to cause cancer. A cancer slope factor is an upper bound 

probability estimate of cancer incidence per unit intake of a carcinogen over a lifetime. Therefore, the 

higher the slope factor, the more carcinogenic a chemical is according to the U.S. EPA. RfDs are used to 

rank a chemical’s ability to cause an adverse health effect other than cancer. According to the U.S. EPA, 

an RfD is an estimated daily intake that if taken over a lifetime, is not expected to cause an appreciable 

risk of adverse health effects. Hence, according to the U.S. EPA, the smaller the RfD, the more toxic the 

chemical. Chemicals were ranked based on slope factors and RfDs independently to distinguish between 

the most important chemicals in terms of cancer risk and adverse health effects. Chemicals that are 

considered carcinogens by the U.S. EPA were ranked based on annual usage multiplied by the cancer 

slope factor. Oral slope factors were used in all but one case because they were more conservative than 

the inhalation slope factor. All chemicals for which the U.S. EPA has published RfDs were ranked by 

multiplying the annual usage by the inverse of the RfD. Some chemicals have both ingestion and 

inhalation RfDs, and in these cases, the more conservative value was used in order to consider the most 

sensitive health endpoint. 

References 

Albuquerque Journal. Potential explosive [perchlorate] builds at LANL. March 24, 2000. 

Dinegar, R. H. Toxic Material Reports for WX-7, December 1979 through December 1980. Repos. No. 

2122. 

Dobratz, Brigitta M. The Insensitive High Explosive TATB: Development and characterization-- 1888-

1994. LA-13014-H. LANL Technical Report Library. August 1995. 

Drake, R. Routine Effluent Reports for GMX-7, May through September 1971. Repos. No. 2114. 

Drake, R.W. and E.H. Eyster. Memorandum from E.H. Eyster to G.L. Voelz. Uranium dispersed by 

experimental test shots at Los Alamos. May 3, 1971. Repos. No. 1412. 

Enders, J. H-5 group correspondence re: CMB and CMF, 1948-1969. Repos. No. 1409. [niobium, 

molybdenum, platinum, samarium, tantalum, aqua regia] 

Enders, J. CMR weekly and monthly reports, 1960-70. Repos. No. 919/2072. [tetrahydrofuran, 

tetrabromoethane]
Table 19-7: Ranking of LANL Chemicals Based on PRGs for Soil

PRG for soil

[mg/kg]

Arsenic 3.90E-01 1

RDX (hexahydro) 4.40E+00 2

Thallium 5.20E+00 3

Perchlorate 7.80E+00 4

TNT (2,4,6-trinitrotoluene) 1.60E+01 5

Uranium 1.60E+01 6

Nitrobenzene 2.00E+01 7

Mercury 2.30E+01 8

Antimony 3.10E+01 9

Vanadium 7.80E+01 10

Molybdenum 3.90E+02 11

Silver 3.90E+02 12

Lead 4.00E+02 13

Lithium 1.60E+03 16

Nickel (soluble salts) 1.60E+03 14

Manganese 1.80E+03 15

HMX (octahydro) 3.10E+03 17

Copper 3.10E+03 18

Fluoride 3.70E+03 19

Barium nitrate 5.40E+03 20

NQ (nitroguanidine; Picrite) 6.10E+03 21

Acetone 1.40E+04 22

Iron 2.30E+04 23

Zinc 2.30E+04 24

Aluminum 7.60E+04 25

Bromine N/A

Gallium N/A

Lanthanum N/A

Niobium N/A

Platinum N/A

Samarium N/A

Tantalum N/A

Zirconium N/A

Chemical Rank

DRAFT FINAL REPORT OF CDC's LAHDRA PROJECT - Chapter 19 19-16
Table 19-8: Ranking of LANL Chemicals Based on PRGs for Air

PRG for air

[microgram/m3]

Chromium (total) 1.60E-04 1

Beryllium 8.00E-04 2

Cadmium 1.10E-03 3

Polychlorinated biphenyls- Aroclor 1242 (1254) 3.43E-03 4

Trichloroethylene 1.70E-02 5

Chloroform 8.30E-02 6

Hexachlorobutadiene 8.60E-02 7

Carbon tetrachloride 1.30E-01 8

Benzene 2.50E-01 9

Tetrachloroethylene 3.20E-01 10

1,4-Dioxane 6.10E-01 11

Tetrahydrofuran 9.90E-01 12

Hydrogen Cyanide 3.10E+00 13

Methylene chloride 4.10E+00 14

Phosphoric acid 1.00E+01 15

Chloromethane 9.50E+01 16

Xylene 1.10E+02 17

Dichlorodifluoromethane 2.10E+02 18

n-Hexane 2.10E+02 20

Toluene 4.00E+02 19

Ethyl Ether 7.30E+02 21

Methanol 1.80E+03 22

Trichloroethane (methyl chloroform) 2.30E+03 23

Ethyl acetate 3.30E+03 24

Methyl ethyl ketone 5.10E+03 25

Ethylene glycol 7.30E+03 26

1,1-Difluoroethane 4.20E+04 27

Chlorodifluoromethane 5.10E+04 28

Naphthalene N/A

Ethanol N/A

Isopropanol N/A

Kerosene N/A

Tetrabromoethane N/A

n-Butyl acetate N/A

Asbestos (magnesium silicate) N/A

Bromide N/A

Hydrochloric acid N/A

Hydrofluoric acid N/A

Nitric acid N/A

Oxalic acid N/A

Sodium hydroxide N/A

Sodium thiosulfate N/A

Sulfur hexafluoride N/A

Sulfuric acid N/A

Baratol (barium nitrate+TNT) N/A

Comp B (60% RDX; 40% TNT) N/A

Cyclotol (70-75% RDX; 25-30% TNT) N/A

Explosive D (NH3 picrate; NH3-1,3,5-trinitrophenol) N/A

Nitrocellulose N/A

Nitromethane N/A

Octol (70-75% HMX; 25-30% TNT) N/A

PBX N/A

Pentolite N/A

PETN (pentaerythritol tetranitrate) N/A

Picric acid N/A

PTX-2 (2,6-bis-picrylamino-3,5-dinitropyridine) N/A

Saltex N/A

TATB (1,3,5-triamino-2,4,6-trinitrobenzene) N/A

Tetryl (1,3,5-trinitrophenyl-methylnitramine) N/A

Torpex (83%Comp B; 17% TNT) N/A

Chemical Rank

19-17 DRAFT FINAL REPORT OF CDC's LAHDRA PROJECT - Chapter 19
Slope Factor (SF)

Reference 

Dose (RfD) Annual Use

[mg/kg-d]-1 [mg/kg-d] [kg] SF x Annual Use Rank 1/RfD x Annual Use Rank

Acetone - 0.9 18,800 - 20,889 13Barium nitrate not in RAIS not in RAIS 108,873 - -Benzene 0.055 0.004 181 10 7 45,250 9Carbon tetrachloride 0.13 0.0007 558 73 5 797,143 5Chlorodifluoromethane2 - 14.3 32,200 - 2,252 17

Chloroform3 0.0805 0.01 3,088 249 4 308,800 7

Dichlorodifluoromethane2 - 0.0571 32,200 - 563,923 6

Dioxane 0.011 - 32 0.35 8 -Methanol - 0.5 6,600 - 13,200 14Methyl ethyl ketone - 0.6 22,000 - 36,667 12Methylene chloride 0.008 0.06 2,200 17 6 36,667 11n-Hexane - 0.06 304 - 5,067 16Tetrachloroethylene 0.54 0.01 10,540 5,692 2 1,054,000 4Tetrahydrofuran not in RAIS not in RAIS 79 - -TNT (2,4,6-trinitrotoluene) 0.03 0.0005 37,950 1,139 3 75,900,909 3Toluene - 0.08 3,300 - 41,250 10chloroform) - 0.2 39,300 - 16,500 8Trichloroethylene 0.4 0.0003 27,719 11,088 1 92,396,667 1Uranium - 0.0006 47,500 - 79,166,667 2Xylene2,4 - 0.0286 290 - 10,140 15

1 All values were obtained from the Risk Assessment Information System (RAIS) available at: http://rais.ornl.gov4 Combined congener values were used (combined, p-, m-, o-). 

Table 19-9: Ranking of LANL Chemicals Based on Toxicity Parameter and Annual Usage1

3 Inhalation cancer slope factor was used because it was more conservative than the oral slope factor. In all other cases, oral slope factors 

were used because they were most conservative

Chemical

Ranked Based on 

Cancer Effects

Ranked Based on 

Non-cancer Effects

2 Inhalation RfD was used because it was more conservative than the oral RfD. In all other cases, oral RfDs were used because they were 

most conservative

DRAFT FINAL REPORT OF CDC'S LAHDRA PROJECT - Chapter 19 19-18
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 19 19-19

English, S.G. Project Crave: Survey of U.S. Atomic Energy Commission Operations and Facilities. 

Brookhaven National Laboratory. BNL-157. February 25, 1952. Repos. No. 2950. 

ESH. Interview with members of the LANL Environmental, Safety and Health Division (ESH-5) 

Jonathan Tapia and Bill Hargraves on January 6, 1999 by Susan Flack of the project team. 

Ferenbaugh, R. W. “Memoranda on LANL Air Emissions: Memo to Harry S. Jordan regarding open 

burning of explosives at S-Site.” January 27, 1981. Repos. No. 611. 

Goldie, R.H. Memorandum from R.H. Goldie, HSE-3, to D. Pinyan, HSE-3. Areas containing or 

contaminated by explosives. October 2, 1984. Repos. No. 658. 

HAI. History Associates, Inc. Site History of Los Alamos (Draft). January 1993. [HE metals] 

IT Corporation. Sampling and Analysis Plan for Mixed Waste Surface Disposal Area at TA-14. 1989. 

Repos. No. 2192. 

Johnson, L.J. and D.A. Dahl. Aerosolized uranium, lead, and beryllium from LASL dynamic 

experiments. LA-UR-77-68. 1977. Repos. No. 2249. 

LANL. Health Division Annual Report, 1951. LA-1256. May 25, 1951. Repos. No. 1349. [naphthalene] 

LANL. Solid Waste Management Units Report. Environmental Restoration Records Processing Facility. 

November 1990. 

LANL. High-Explosives Wastewater Treatment Facility- An environmental success story [HE, acetone, 

methanol, ethanol]. LALP-98-84. 1998. 

LANL. Laboratory releases surveillance well data [oxalate]. LANL News Release. April 17, 1998. 

LANL. Lab releases first information from third characterization well [HMX, RDX, TNT]. Los Alamos 

National Laboratory News Release. January 28, 1999. 

LANL. Perchlorate detected in water-supply well. Los Alamos National Laboratory News Release. July 

20, 2000. 

LANL. Laboratory detects perchlorate in shallow groundwater. LANL News Release. March 2, 2000. 

LANL Environmental Restoration Project. RFI Report for OU 1071 – leakiage from PCB transformers. 

April 1993. Repos. No. 1269. 

LANL Environmental Restoration Project. Fact Sheet: Material Disposal Areas. February 4, 1999. [HE] 

Ramsay, John B. “HE Incidents and Accidents at LANL 1951-1999”, LA-13697-H, March 2001. 

Santa Fe Engineering. Storm Water Pollution Prevention Plan. June 1995. Repos. No. 1262. 

Santa Fe New Mexican. “LANL finds still-potent explosives during excavation of dump site.“ November 

10, 1999. 

Schulte, H.F. Industrial Hygiene Progress Reports, 1949-1950. Repos. No. 668. [naphthalene] 
19-20 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 19

Unknown author. Summary of wastes and effluents at Omega Site (TA-2). August 27, 1973. Repos. No. 

645. [chromium] 

Unknown author. Chronological record of accidents at LASL. 1979. Repos. No. 514. 

Unknown author. PCB cleanup at TA-3 (OU#1114), 1995-97. Repos. No. 1094. 

Unknown author and date. Disposal of hazardous materials by burning. Central Records Center. Repos. 

No. 672. 

U.S. Congress. Office of Technology Assessment. Complex Cleanup- The environmental legacy of 

nuclear weapons production. February 1991. 

USDOE. U.S. Department of Energy. The 1996 Baseline Environmental Monitoring Report. Volume III 

– New Mexico – Wyoming. DOE/EM-0290. June 1996. 

USEPA Region 9 Preliminary Remediation Goals. 

http://www.epa.gov/region09/waste/sfund/prg/files/02table.pdf

October 1, 2002. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20 20-1

Chapter 20: A Screening-Level Evaluation of Airborne 

Beryllium Releases from LANL Operations 

Introduction 

Historical records indicate that beryllium was used at Los Alamos for some time before its health hazards 

were fully recognized (Shipman 1951, Hempelmann and Henrickson 1986). While beryllium became 

recognized as a worker health hazard, potential exposures to members of the public who lived in Los 

Alamos have not been as well characterized. Because residents lived closer to production and testing 

areas at Los Alamos than at any other nuclear weapons complex site, this screening-level assessment of 

potential public exposures was undertaken. 

Identification of Sources of Beryllium Releases at LANL 

Based upon the review of information collected under the LAHDRA project, screening level assessments 

were completed for the following historical operations at Los Alamos that involved processing or use of 

significant quantities of beryllium: 

• Early machining operations at a shop in the Original Technical Area, TA-1, known as V Shop 

• Machining in shops at TA-3, Building SM-39, that started late in 1953 

• The testing of atomic bomb components by firing them from a 20-mm anti-aircraft autocannon in an 

annex to B Building at TA-1 

• The hot pressing of beryllium oxide powder in Q Building at TA-1 to make reactor components 

• The expenditure of beryllium in explosive tests conducted at the PHERMEX facility at TA-15 

Estimation of Release Rates over Averaging Periods Shorter Than a Year 

Limits on occupational and public exposures to beryllium are stated as concentrations that vary with 

averaging time, including those specified for instantaneous concentrations as well as 8-h and 30-d average 

concentrations. Generally, the shorter the exposure (or stack sampling) time is, the higher the allowed 

concentration. However, reported LANL air concentrations of beryllium are often reported or can only be 

estimated in terms of annual averages or totals released over a year. During any year, concentrations over 

short periods will be greater than (and at other times also less than) the annual average. Because there is 

evidence to suggest that the occurrence of chronic beryllium disease is not related to duration of exposure 

(ATSDR 2002), indicating that exposures over short periods can be of health significance, the LAHDRA 
20-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20

team recognized the need for a method to predict the upper bounds of airborne beryllium concentrations 

over time intervals from less than an hour to 30 d based on data that represent concentrations or releases 

over a full year. 

In order to estimate the magnitude of the variations of airborne concentrations that one would expect 

within a year, a study was made of another material released in particulate form by LANL, plutonium. 

Like beryllium, facilities that exhaust plutonium to the air have been subject to increasingly stringent 

controls, resulting in the use of filters on the exhausts in the 1950s and high efficiency particulate air 

(HEPA) filters by the mid-1960 for both contaminants. Like beryllium, samples of the exhaust air from 

plutonium facilities at LANL have been collected on filters to assess effluent air concentrations. Further 

discussion of similarities between particles of plutonium and beryllium, how they behave, and how they 

have been assessed by others is provided elsewhere (Shonka 2009). Unlike beryllium, however, 

plutonium samples have been routinely reported for time intervals as short as a work day. 

In order to estimate how high beryllium release rates from chronic release sources could have been over 

averaging periods shorter than a year, the detailed monitoring data that are available for airborne 

plutonium releases from DP West Site stacks for 1956 and 1957 were analyzed. The relationships 

between work-day averaged concentrations and weekly, monthly, and annual average concentrations were 

characterized, and a table of multipliers was generated that can be applied to annual data to estimate peak 

releases over a series of shorter durations. To support this preliminary screening, airborne beryllium 

releases were assumed to vary over time like the measured airborne plutonium releases (that is, having 

similar ratios of annual averages to averages over shorter periods), and estimated annual beryllium 

releases were converted to release rates over shorter durations so that airborne concentrations over 

appropriate averaging periods could be compared to occupational and ambient exposure limits. If further 

evaluation of historical beryllium operations and releases is undertaken, a more detailed analysis of 

operational and air sampling data for beryllium activities might support a more direct characterization of 

the temporal variations of beryllium concentrations in exhaust streams. 

Nine-hour averaged air concentrations of plutonium (corresponding to weekday working hours) for the 

four main stacks on Building 12 at DP West Site for calendar years 1956 and 1957 were entered into a 

spreadsheet. Raw daily data have not been located for earlier years. HEPA filters were added to the 

process exhaust system at DP West in 1959, and because the bulk of the releases from the facility appear 

to have come from exhausts that were not HEPA filtered, the earlier data was chosen as most 

representative of the conditions of greatest interest. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20 20-3

Averages were computed for 9 h (the raw data) as well as for weekly (45 h), monthly (196 h) and annual 

(2,349 h) averages. The data were maintained as 9-h working days in order to match the recorded data. 

In addition, the actual days for each week and month within 1956 and 1957 were maintained. Except for 

the annual average data, which had only one data point for each series (1956 and 1957), the data for each 

averaging period were fit to lognormal distributions with excellent residuals. 

One can fit a lognormal distribution to an equation of the form y = a × ebx , where y is the natural log of 

the observed concentration and x is the standard deviation. The exponential constant (eb

 in the equation y 

= a × ebx) provides the geometric standard deviation of the lognormal distribution. Both 1956 and 1957 

had similar exponential factors, and the data were averaged for a best estimate. Examination of the data 

showed no general time dependence in concentration over the course of a year (such as slow falloff with 

time), even though LANL emissions did trend lower over the decades of DP West operations. The “b” 

value was plotted as a function of the log of the integration time and fit to a linear equation. With this 

equation, the geometric standard deviations (eb

) for treated particulate releases were predicted for various 

integration times ranging from 6 min to one month. 

The analyses of the releases from DP West are summarized in Table 20-1 below. The 95th percentile for 

monthly data would correspond (roughly) to a concentration reached on one day of each month. As one 

goes to shorter time intervals, the 95th percentile is reached more and more often, and is not a useful factor 

to use for a conservative analysis. For example, using the 95th percentile, the 1-h data would be expected 

to either be larger or smaller than the annual average by a factor of 8.2 for 1 h out of every 20. Thus, 

hourly data would expect to be exceeded every 1 or 3 d, and 6 min (0.1 h) data would be seen as often as 

twice a day. As a result, the table also lists the multiplicative factor that would be found for a 

concentration that would be attained once per 1600-h work year. Using the “once per year” values, one 

can see from Table 20-1 that the 1-h data would exceed the annual average values by a factor of 30 for the 

estimated highest hour of the 1600 hour work year. Although the regulatory requirements dictate an 

instantaneous limit, this analysis has limited the averaging period to a minimum of 0.1 h. The data 

indicate that at 30 min of sampling or exposure time (0.5 h) the concentration would exceed annual 

averages by a factor of 47 once per year. No “once per year” multipliers are provided for weekly or 

monthly time periods. The 95th percentile should be used for screening for those time periods. The 

duration factors are not used in the estimation of episodic releases, for which releases for each event were 

estimated and converted to average concentrations over longer periods based on assumed numbers of 

events of stated material content within each period. 
20-4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20

Table 20-1. Geometric standard deviation data based on analysis of detailed DP West plutonium stack 

sampling data, with factors to estimate release rates over periods shorter than 1 y

Multiplicative factors to be applied to annual 

values to estimate values over specified intervals 

Time Interval Equivalent 

Hours “b” Value a

 95th Percentile Once per year 

6 min 0.1 1.3 13.6 149 

30 min 0.5 1.1 9.5 47 

Hour 1 1.1 8.2 30 

Work Day 8 0.8 5.2 8.3 

Day 24 0.7 4.1 4.6 

Work Week 40 0.6 3.6 

Week 168 0.5 2.7 

Month 730 0.3 1.9 

Work Year 1,600 0.2 1.6 

Year 8,760 0 1 

a The term eb

 represents the geometric standard deviation of the lognormal distribution fitted to DP West stack 

sample analysis results. 

 Estimation of Beryllium Release Rates for Identified Emission Sources 

Fabrication of components from beryllium metal and oxide (TA-1 and TA-3)

a) New Beryllium Shop (TA-3, South Mesa Building 39, “SM-39,” Beryllium Shop 4) 

South Mesa Building 39, “SM-39,” Beryllium Shop 4 was outfitted with a HEPA filter on the exhaust 

in 1964. Release measurements after this time period were found for 6 y in the 1960s and reported in 

a manner that permits annual average releases to be computed. The study of DP West stack 

particulate releases of plutonium, discussed earlier, provide a means to estimate the concentrations for 

shorter time periods. The exhaust system apparently ran only during normal working hours. 

LAHDRA does not know if the stack sampler pump was only operated when the stack exhaust fan 

was operating. This assessment assumes that the sampler pump also only ran during the hours of 

operation. If it did not, then the “sampler hours of operation” correction would provide an additional 

factor of 5.5 increase for the total beryllium released, (= 8760 h / 1600 h) since the concentration in 

the stack would be expected to be much lower when the machining operations ceased during nonworking hours. The documentation of the data for 1964 through 1966 did not identify fan hours of 

operation, so the average of the operating hours (1600) for the 1968 through 1970 period was chosen. 

Table 20-2 and Table 20-3 below summarize the release data found (LASL 1969, 1970). Table 20-3 

has the duration factors from Table 20-1 for each time interval applied to the data from 1970 to 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20 20-5

permit comparison with applicable limits. The screening calculations utilize 1970, the highest year 

that has been found to date. 

The annual release rate for 1600 h (0.0245 μg s-1 for 1970) must be adjusted by 1600 h /8760 h to 

correctly express the average release rate in a year. In Table 20-2, the “Working Hours” column 

refers to the fan operating time, which is also the operational release period. The Mass Released 

column is the release for the specified year. The stack flow rate was 2,000 ft3 min-1 (LASL 1970). 

In Table 20-3, the time periods of one day or longer have been corrected for the fact that the release 

occurs over a shorter time than the integration period. For example, the year release rate is 0.0245 

μg s-1 times 1602.6 h of operation divided by 8760 h y-1. For time periods less than the operating 

period (i.e., 1 h or less), this factor is no longer applied, since the 6 to 9 h workday was longer than 

those time periods, so correcting for the time the stack exhaust was not operating is not needed. 

The work day time period corresponds to an 8 h day, the work week to a 40 h period, the month to a 

730 h period, and the year to 8760 h. These were chosen in order to permit comparison to 

occupational and ambient exposure limits. 

Table 20-2. Measured beryllium releases from SM-39 shop at TA-3 after 1963

Year Working 

Hours Mass Released, g Working Hours Release Rate, μg s-1 

1964 1600 0.0105 0.0018 

1965 1600 0.0106 0.0018 

1966 1600 0.0188 0.0033 

1967 No data found 

1968 1545.7 0.0089 0.0016 

1969 1687.7 0.0378 0.0062 

1970 1602.6 0.1416 0.0245 

Table 20-3. Estimated SM-39 beryllium shop release rates after 1963 based on measurements made in 

1970 and application of duration factors

Release Rate for Stated Averaging Period, μg s-1

Year 6 min 30 min Hour Work Day Work Week Month Year 

1970 3.65 1.16 0.73 0.20 0.089 0.0086 0.0045 
20-6 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20

b) TA-3, SM-39 Beryllium Shop Operations 1953 - 1963 

The beryllium shop at SM-39 was put into operation in 1953 to replace the inadequate facilities in the 

main shop at V Building in the Original Technical Area. At the start of operations, no provisions 

were made for HEPA filtration of exhausts. Release measurements were not found for the SM-39 

shop in this era. In order to estimate a lower bound for air concentrations and releases from the SM39 beryllium shop from 1953 to 1963, measurements from the late 1960s were adjusted to account for 

the fact that no HEPA filters were in place. In general, HEPA filters are considered to attain a 

filtering efficiency of 99.97% (USDOE 2003). This corresponds to a reduction of the effluent by a 

factor of 3,333 (=1/ (1-0.9997)). This efficiency is obtained at a particle size diameter of 0.3 μm in 

diameter, with better efficiencies realized for smaller and larger particles. Data indicate that the filter 

systems used during this era attained efficiencies in the 90% range. An assumed 95% efficiency 

would attain reduction by a factor of 20. The ratio of the pre- and post-1964 filter reduction factors is 

167 (=3,333/20). For this assessment, SM-39 exhaust monitoring data from 1970 were multiplied by 

167 to estimate release rates for 1953 through 1963 (see Table 20-4). Use of this factor likely 

understates the releases by a considerable amount, given that the airborne particles larger or smaller 

than 0.3 micron diameter would have been filtered more efficiently. A partially offsetting factor for 

this conservatism may come from the fact that an improperly installed HEPA filter may not have 

attained 99.97% efficiency. Because the values represent long term averages, they were multiplied by 

the factors in Table 20-1 for the desired sampling or exposure time to provide the data in Table 20-5. 

For comparison purposes, the 1970 data that were the basis for 1953-1964 is repeated in Table 20-5. 

The 1,600 h y-1 exhaust operating period was also assumed. The impact of the lack of HEPA filters 

before 1964 is readily seen in Table 20-5 by comparing the 1953–1963 data with the 1970 values. 

Table 20-4. Estimated airborne releases from the SM-39 beryllium shop from 1953 to 1963

Year 

Working 

Hours 

Annual Average 

Concentration, μg m-3

Mass 

Released, g 

Working Hours 

Release Rate, μg s-1

1953 – 1963 1600 4 24 4 

1970 1602.6 0.0260 0.1416 0.0245 

Table 20-5. Estimated SM-39 beryllium shop release rates for 1953–1963 based on measurements in 

1970, correction for non-HEPA filtration, and application of duration factors 

Release Rate for Stated Averaging Period, μg s-1

Year 6 min 30 min Hour Work Day Work Week Month Year 

1953-1963 610 194 122 34 15 1.4 0.7 

1970 3.65 1.16 0.73 0.20 0.089 0.0086 0.0045 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20 20-7

c) V-Building Shop Operations at TA-1 between 1949 and 1953 

The main shops in V Building at the Original Technical Area, TA-1, were used for machining 

beryllium prior to the startup of the SM-39 shop at TA-3 in 1953. Around late 1948, when LANL 

was informed of the hazardous nature of beryllium, the high speed machining operations were 

relocated into an annex to V Building and an exhaust system was added with filters. For the purposes 

of this analysis, it was assumed that the non-HEPA filters that were used had comparable filtering 

efficiencies to the filtering system used at the SM-39 shop at TA-3 before HEPA filtration was added. 

Because the operations in the V Building shop appear to have been grossly similar to those at the SM39 shop, the estimated release rate for the SM-39 shop for 1953-1963 was used for V Building shop 

from 1949 to 1953. The main difference between the two emission sources in terms of prioritization 

will be the shorter separation of V Building from nearby residences. Estimated beryllium releases 

are summarized in Table 20-6 and applied to various averaging periods in Table 20-7. 

Table 20-6. Estimated airborne releases from the V-Building shop at TA-1 from 1949 to 1953 

Year 

Working 

Hours 

Annual Average 

Concentration, μg m-3

Mass Released, 

g 

Working Hours 

Release Rate, μg s-1

1949 – 1953 1600 4 24 4 

Table 20-7. Estimated V-Building beryllium shop release rates for 1949 through 1953 with duration 

factors applied

Release Rate for Stated Averaging Period, μg s-1

Year 6 min 30 min Hour Work Day Work Week Month Year 

1953-1963 610 194 122 34 15 1.4 0.7 

d) V-Building Shop Operations at TA-1 between 1943 and 1948 

At the start of LANL, the main shops in V Building at TA-1 were used for machining beryllium. 

Prior to around 1948, when LANL was informed of the hazardous nature of beryllium, the operations 

occurred in the shop itself with no specialized exhaust ventilation. Because the nature of the 

operations at the V-Building shop appear to have been grossly similar to the SM-39 shops at TA-3, 

use of that release rate estimate is appropriate. However, the releases were not collected by a process 

exhaust system and were not released through a stack. We assume that the releases occurred from the 

normal ventilation of the shop area, perhaps a ventilation fan. In contrast to the case of the post-1949 

V-shop operations, the main change in prioritization will be the diffuse release through building 
20-8 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20

ventilation as opposed to a stack. As in the case of the V-Building shops 1949 - 1953, because the 

nature of the operations was grossly similar to the TA-3 shops, use of the release rate estimate for the 

SM-39 shop 1953-1963 is appropriate. As for all sources of chronic releases, the Table 20-1 factors 

were applied to correct the annual average to the sampling or exposure time of interest. Estimated 

beryllium releases are summarized in Table 20-8 and applied to various averaging periods in Table 

20-9. 

Table 20-8. Estimated airborne releases from the V-Building shop at TA-1 from 1943 to 1948

 Year 

Working 

Hours 

Annual Average 

Concentration, μg m-3

Mass Released, 

g 

Working Hours 

Release Rate, μg s-1

1943 – 1948 1600 87 472 82 

Table 20-9. Estimated V-Building beryllium shop release rates for 1943 through 1948 with duration 

factors applied

Release Rate for Stated Averaging Period, μg s-1

Year 6 min 30 min Hour Work Day Work Week Month Year 

1943-1948 12,156 3,859 2,427 679 297 29 15 

Gun Testing of Atomic bomb Initiators Containing Beryllium– B Building Annex at TA-1

If one approximates an atomic bomb initiator as a sphere of beryllium of a radius given by the 20-mm 

barrel diameter of the gun at B Building, each of the daily initiator tests used 566 g (the mass of a metal 

sphere of beryllium of 10 mm radius), and an estimated 10% was aerosolized and exhausted from the 

room, or 57 g per test. Documents that describe initiator testing have a data block that lists typical values 

of 90 to 120 “Gr” projectile weights. This mass is close to the mass of a normal projectile the autocannon would fire, and would be consistent with grams rather than grains. If the projectile weight was in 

grains, only 8 g would be used for the entire projectile, which seems too low in mass to be realistic. 

Using the stated mass of the projectile would mean that the beryllium released would be five times less 

that stated earlier (solid sphere of beryllium of 20 mm diameter) for each shot. For this initial assessment, 

120 g is assumed expended, of which 10% was released. During the first 180 d of the program, 180 

initiator tests were conducted. That being the case, it appears that the B- Building Annex alone released 

more than 2160 g (10% of 120 g for 180 tests) over the one half year in 1944 for which data were found. 

This would amount to 4,320 g y-1. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20 20-9

After each test was fired, the 10% fraction assumed to be aerosolized was dispersed into the room and 

removed by the ventilation system. It as assumed that a flow rate sufficient to produce 12 air changes per 

hour was used. If the beryllium was uniformly mixed into the room volume, the concentration would 

drop exponentially with a time period equal to the inverse of the ventilation rate. A time sufficient to 

produce two air changes (0.1 h or 6 min) would remove most of the beryllium and was assumed to be the 

release period. Thus, the release would correspond to 12 g of beryllium over 360 s, or 0.033 g s-1. The 

data sheets reviewed indicate test frequency of roughly once per day. Thus, a test was assumed to occur 

365 days per year. Because the release rate considers the release time, the duration factors of Table 20-1 

are not applied for these episodic releases. With a release each day (365 d y-1) and duration of 0.1 h, the 

release is assumed to occur over a 36.5-h operating period. However, the release rate when averaged over 

longer periods of time drops with the ratio of the averaging period to that of the considered duration of 

release. No annual average concentration is provided. The hours of operation of what is believed to have 

been a nominal 600 ft3 min-1 ventilation fan are not known. Estimated beryllium releases are summarized 

in Table 20-10 and applied to various averaging periods in Table 20-11. 

Table 20-10. Estimated airborne beryllium releases from B-Building gun testing at TA-1, 1944-1948 

 Years Operating Period, h Mass Released, g Release Rate, μg s-1

1943 – 1948 36.5 4,320 33,333 

Table 20-11. Estimated beryllium release rates from B-Building gun testing (duration factors not 

applied) 

Release Rate for Stated Averaging Period, μg s-1

Years 6 min 30 min Hour Work Day Work Week Month Year 

1943-1948 33,333 6,667 3,333 417 417 139 139 

 

Explosive testing of bomb components containing beryllium

During the peak year of dynamic testing, 1964, a total of 106 kg of beryllium was used at TA-15, a 

fraction of which was aerosolized into fine particulate form that would distribute downwind. While 

LANL has traditionally assumed 2% of the mass is aerosolized, this assumption (along with others) fails 

to account for the mass of beryllium expended at the firing sites and found in nearby soils. Lawrence 

Livermore National Laboratory (LLNL) has used assumptions that 8% of the mass is aerosolized. Both 

of those values (either 2% or 8%) were the result of experiments conducted by the laboratories. Finally, 

the Dual-Axis Radiographic Hydrodynamics Test (DARHT) facility EIS, which was published more 
20-10 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20

recently, assumed a value of 10%. For this analysis, it was assumed that 10% of the 106 kg expended in 

1964 was aerosolized. 

The amount of beryllium used in a specific experiment is classified. In order to estimate a release rate, it 

was assumed that between 50 and 150 experiments were performed at the three firing sites during the year 

(less than once per week), with a total of 100 experiments performed. It was assumed that 80% of the 

experiments did not use beryllium at all, and of the 20 experiments that did, 16 used small amounts of 

beryllium (together accounting for 50% of the total mass) and 4 of them used larger amounts (together 

accounting for 50% of the total mass). Each of the larger experiments might have used 13.25 kg. 

The duration of the exposure from the explosive test was taken to be 0.25 h as the puff drifted off-site 

with the prevailing wind. This heuristic estimate is based partially on the estimated size of the puff a 

short time after detonation and subsequent dispersion of that puff as it drifts approximately 5,000 m off 

site with an average wind speed. 

Because the release rate considers the release time, the factors of Table 20-1 are not needed. Table 20-12 

provides the annual average values (10% of 106 kg dispersed in 0.25 h × 100 tests = 25 h) as well as the 

peak (one of 4 tests in the year that dispersed 10% of 13.25 kg in 0.25 h). Table 20-13 applies the peak 

rate to time intervals of a week or less, and assumes the annual release rate for the year and the month. If 

one had assumed that one of the shots that month was one in which 13.25 kg was used (and the rest 

averaged the 1.06 kg), then the month would be a factor of 2.3 times larger. This was not used in order to 

maintain a simpler set of assumptions. Using this method provides an average rate for the month equal to 

the annual rate. In fact, it is likely that the month in which a larger than average quantity of beryllium 

was used in shots had higher release rates than 336 μg s-1 over the 730 h period. This can be accounted 

for if assessment of beryllium releases continues and detailed (classified) shot records are retrieved and 

summarized in a manner that would be publicly releasable. 

Table 20-12. Estimated airborne beryllium releases from TA-15 explosive testing

 Year 

Duration of 

Exposure, h Mass Released, g Release Rate, μg s-1

1964 (year) 25 10,600 117,778 

1965 (month) 2.08 1,766 235,467 

1964 (maximum shot) 0.25 1,325 1,472,222 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20 20-11

Table 20-13. Estimated beryllium release rates from TA-15 explosive testing (duration factors not 

applied) 

Release Rate for Stated Averaging Period, μg s-1

Year 6 min 30 min Hour Work Day Work Week Month Year 

1964 1,472,222 736,111 368,056 46,007 9,201 672 336 

Hot Pressing of Beryllium Oxide Powder in Q Building at TA-1 

LANL ordered 6,100 lbs of beryllium oxide (BeO) for use in reactors by January 15, 1944 (LASL 1944). 

For this assessment, it was assumed that the 6,100 lbs of BeO powder that was ordered was actually used 

in 1944. This is a metric ton of the element beryllium alone. 

In order to estimate the amount of BeO (and Be) that would be released; the methods of the USDOE 

Handbook of Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear 

Facilities were used (USDOE 1994). For this application, it was necessary to estimate an Overall Release 

Fraction (ORF). The Atmospheric Release Fractions (ARF) and Respirable Factions (RF) were then 

multiplied to get a range of Overall Release Fractions (ORF). The geometric mean of the ORF, computed 

as 0.0025 (the square root of the product of the upper and lower bounds), was then applied to the total 

BeO ordered for 1944. 

The ARF was estimated as between 5% of the mass on the high end, and 0.5% of the mass on the low 

end. The RF was estimated as the mass fraction below 5 μm diameter. The upper bound was estimated 

from the known upper size limit (-325 mesh or 44 μm) and an assumed geometric standard deviation of 3 

for the particle size. Two standard deviations (3×3 = 9) were used to estimate the geometric mean of 5 

μm, which means one half of the mass of BeO was below 5 μm and was respirable. A value for respirable 

fraction (RF) that was ten times smaller was used as an estimate for the lower bound. These values are 

summarized in Table 20-14. 

Table 20-14. Release fraction parameter values for BeO powder processing

 Upper Bound Lower Bound 

Airborne Release Fraction (ARF) 0.05 0.005 

Respirable Fraction (RF) 0.5 0.05 

Overall Release Fraction (ORF) 0.025 0.00025 

Geometric Mean of ORF 0.0025 
20-12 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20

Applying the geometric mean of the overall release fraction (0.25%) to the 6,100 pounds of BeO used in 

1944 results in a release of 6,932 g of respirable BeO from Q Building during the year, which would have 

contained 2,495 g of beryllium. Table 20-15 and Table 20-16 provide the total releases and the release 

rates with duration factors applied for Q-Building BeO powder pressing during 1944. It can be assumed 

that these releases likely continued to occur until the late 1940s, when LANL began to impose more 

stringent controls on beryllium operations. 

Table 20-15. Estimated airborne beryllium releases from BeO powder pressing in Q Building at TA-1 

 Year Duration of Exposure, h Mass Released, g Release Rate, μg s-1

1944 1600 2,495 433 

Table 20-16. Estimated beryllium release rates from BeO pressing in Q Building at TA-1 with duration 

factors applied 

Release Rate for Stated Averaging Period, μg s-1

Year 6 min 30 min Hour Work Day Work Week Month Year 

1944 64,475 20,468 12,872 3,600 1,574 152 79 

Estimation of Atmospheric Dilution Factors 

Beryllium Machining at V Shop in the Original Technical Area

Based on review of drawings and 1940s photographs of the Original Technical Area, there was no stack 

on V Building that met or exceeded the 2.5-times building height criterion for avoidance of building ake 

effects. Because of this, building wakes will be a consideration. Based on review of drawings and 

photographs of the Original Technical Area, the surface area of V Building, AG, was approximately 39 m 

× 15 m = 585 m2

, the square root of which is 24.2 m; 2.5 times that value is 60.5 m. The distance from V 

Building to the nearest residence, the southernmost Sundt apartment on 24th Street, was approximately 

165 m (see Fig. 20-1). As this value exceeds both 2.5-times the square root of AG and 100 m, this is a 

case of exposure outside the near-wake region. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20 20-13 

Fig. 20-1. Approximate distances from Original Technical Area beryllium facilities to nearest residences
20-14 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20

u

f Q B C =

The concentration at the exposure point can therefore be estimated as follows (NCRP 1996): 

 

 

 

 Where: C = average atmospheric concentration at receptor, μg m-3

 f = fraction of time that the wind blows toward the receptor of interest 

 Q = effluent release rate (μg s-1 in this application) 

B = the Gaussian plume model diffusion factor modified for building wake 

effects 

u = mean wind speed, m s-1 

Because the distance, x, to the nearest potentially exposed individual is less than 2 km, Figure 1.5 of 

NCRP Report 123 was used to determine B. That figure indicates that a value of 9×10-4 m-2 should be 

used for B when x = 165 m and AG falls between 300 and 1,000 m2

. The NCRP Report 123 method 

incorporates a value of 0.25 for f, and recommends a default of 2 m s-1 for u when site specific data are 

not available. The above equation can be rearranged to yield a relative concentration (concentration for a 

unit release rate), C/Q, as follows: 

C/Q = (0.25) (9×10-4 m-2) (2 m s-1)

-1 = 1.13×10-4 s m-3

This value can be multiplied by the estimated release rate of beryllium from V Building (μg s-1) to 

estimate the airborne beryllium concentration (μg m3

) at the southernmost Sundt apartment on 24th street 

in Los Alamos. For evaluation of episodic releases, when it is appropriate to assess concentrations when 

the wind is blowing toward the identified nearest exposure point, f will be set to 1, and relative 

concentrations will be four times the C/Q value shown above. 

Beryllium Oxide Pressing at Q Building in the Original Technical Area

Based on review of drawings and 1940s photographs of the Original Technical Area, there was no stack 

on Q Building that met or exceeded the 2.5-times building height criterion. Because of this, building 

wakes will be a consideration. Based on review of drawings and photographs of the Original Technical 

Area, the surface area of the Q Building, AG, was approximately 10 m × 5 m = 50 m2

, the square root of 

which is 7.1 m; 2.5 times that value is 17.7 m. The distance from Q Building to the nearest residence, the 

southernmost Sundt apartment on 25th Street, was approximately 136 m (see Fig. 20-1). As this value 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20 20-15 

u

f Q B C =

exceeds both 2.5-times the square root of AG and 100 m, this is a case of exposure outside the near-wake 

region. 

The concentration at the exposure point can therefore be estimated as follows (NCRP 1996): 

 . 

 

 Where: C = average atmospheric concentration at receptor, μg m-3

 f = fraction of time that the wind blows toward the receptor of interest 

 Q = effluent release rate (μg s-1 in this application) 

B = the Gaussian plume model diffusion factor modified for building wake 

effects 

u = mean wind speed, m s-1 

Because the distance, x, to the nearest residence is less than 2 km, Figure 1.5 of NCRP Report 123 was 

used to determine B. That figure indicates that a value of 2×10-3 m-2 should be used for B when x = 136 m 

and AG falls between 0 and 100 m2

. The NCRP Report 123 method incorporates a value of 0.25 for f, and 

recommends a default of 2 m s-1 for u when site specific data are not available. The above equation can 

be rearranged to yield a relative concentration (concentration for a unit release rate), C/Q, as follows: 

C/Q = (0.25) (2×10-3 m-2) (2 m s-1)

-1 = 2.5×10-4 s m-3

This value can be multiplied by the estimated release rate of beryllium from Q Building (μg s-1) to 

estimate the airborne beryllium concentration (μg m3

) at the southernmost Sundt apartment on 25th street 

in Los Alamos. For evaluation of episodic releases, when it is appropriate to assess concentrations when 

the wind is blowing toward the identified nearest exposure point, f will be set to 1, and relative 

concentrations will be four times the C/Q value shown above. 

Beryllium Processing in the SM-39 Shops at TA-3

The photographs and documents that have been reviewed indicate that associated releases were not 

exhausted through a stack that met or exceeded the 2.5-times building height criterion for nearby 

structures. Because of this, building wake will be a consideration. The distance from Building SM-39 to 

the closest residential area, Western Area housing, is approximately 960 meters (Fig. 20-2). Based on 

review of aerial photographs of SM-39, the width of the north end of the building is approximately 76 m. 

Based on review of historical photographs, the height of that building is approximately that of a two story 
20-16 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20

u

f Q B C =

building, or roughly 7 m. The cross-sectional area of the north end of the building is therefore 532 m2, 

the square root of that value is 23, and 2.5-times the square root is 58. As the distance to the nearest 

public exposure point exceeds 2.5-times the square root of AG, this is a case of exposure outside the nearwake region. The concentration at the exposure point can be estimated as follows (NCRP 1996): 

 

 

 

 Where: C = average atmospheric concentration at receptor, μg m-3

 f = fraction of time that the wind blows toward the receptor of interest 

 Q = effluent release rate (μg s-1 in this application) 

B = the Gaussian plume model diffusion factor modified for building wake 

effects 

u = mean wind speed, m s-1 

Because the distance to the nearest residence, x, is less than 2 km, Figure 1.5 of NCRP Report 123 was 

used to determine B. That figure indicates that a value of 5.5×10-5 m-2 should be used for B when x = 960 

m and AG falls between 300 and 1,000 m2

. The NCRP Report 123 method incorporates a value of 0.25 for 

f, and recommends a default of 2 m s-1 for u when site specific data are not available. The above equation 

can be rearranged to yield a relative concentration (concentration for a unit release rate), C/Q, as follows: 

C/Q = (0.25) (5.5×10-5 m-2) (2 m s-1)

-1 = 6.88×10-6 s m-3

This value can be multiplied by the estimated release rate of beryllium from the SM-39 shops to estimate 

the airborne beryllium concentration (μg m3

) at the southernmost residences of the Western Area in Los 

Alamos. For evaluation of episodic releases, when it is appropriate to assess concentrations when the 

wind is blowing toward the identified nearest exposure point, f will be set to 1, and relative concentrations 

will be four times the C/Q value shown above. 

Gun Testing of Weapon Components in the Annex to B Building in the Original Technical Area

Based on review of drawings and 1940s photographs of the Original Technical Area, there was no stack 

on B Building that met or exceeded the 2.5-times building height criterion. Because of this, building 

wakes will be a consideration. The surface area of the building, AG, is approximately 62 m × 15 m = 930 

m2

, the square root of which is 30.5 m; 2.5 times that value is 76.2 m. The distance from the center of the 

rear (southern facing) side of B Building to the southernmost Sundt apartment on 25th Street in Los 

Alamos was 49 m (Fig. 20-1). As this is less than both 2.5-times the square root of AG and 100 m, this is 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20 20-17 

Fig. 20-2. Approximate distance from Building SM-39 at TA-3 to the southernmost residences of the 

Western Area in Los Alamos 
20-18 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20

u h K

f Q C

π =

u

f Q B C =

a case of exposure in the near-wake region. The concentration at the exposure point can therefore be 

estimated as follows (NCRP 1996): 

 

 

 Where: k = a constant of value 1 m, and 

h = the smaller of the building height or building width, m. 

 In this case, building height, hb (~15 m) is less than its width, hw (~62 m). 

The above equation can be rearranged to yield a relative concentration (concentration for a unit release 

rate), C/Q, as follows. Because the B-Building gun tests were episodic releases, concentrations will be 

estimated for the conditions when the wind was blowing toward the identified nearest exposure point by 

setting f to 1. 

C/Q = (1)[(3.14) × (2 m s-1) × (15 m)]-1 = 1.06 × 10-2 s m-3

This value can be multiplied by the estimated release rate (μg s-1) of beryllium from the back center of B 

Building to estimate the airborne beryllium concentration (μg m3

) at the southernmost Sundt apartment on 

25th Street in Los Alamos. 

Beryllium Expended in Explosive Testing at TA-15 (PHERMEX facility)

Based on review of drawings, photographs, and descriptions of the TA-15 facilities, associated releases 

were not exhausted through a stack that met or exceeded the 2.5-times building height criterion for nearby 

structures. Because of this, building wakes (or wakes from nearby structures) will be a consideration. 

The distance from the main PHERMEX building to the nearest residential area, the Royal Crest Trailer Park 

on East Jemez Road, is approximately 4,500 m (see Fig. 20-3). There were no large buildings in the 

immediate area of PHERMEX. As the distance to the nearest public exposure point exceeded 2.5-times the 

square root of AG for all buildings in the area of the testing, this is a case of exposure outside the near-wake 

region. Because the distance to the nearest public exposure point exceeds 2 km, the concentration at the 

exposure point can be estimated as follows (NCRP 1996): 

 

 

 Where: C = average atmospheric concentration at receptor, μg m-3

 f = fraction of time that the wind blows toward the receptor of interest 
 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20 20-19 

 Q = effluent release rate (μg s-1 in this application) 

P = the Gaussian plume model diffusion factor as a function of downwind 

distance assuming a release height (H) at ground level, 0 m. 

u = mean wind speed, m s-1 

Because x is greater than 2 km, Figure 1.4 of NCRP Report 123 is used to determine P. That figure 

indicates that a value of 5×10-6 m-2 should be used for P when x = 4500 m and H = 0 m. The NCRP 

Report 123 method incorporates a value of 0.25 for f, and recommends a default of 2 m s-1 for u when site 

specific data are not available. The above equation can be rearranged to yield a relative concentration 

(concentration for a unit release rate), C/Q, as follows. Because the PHERMEX explosive tests were 

episodic releases, concentrations will be estimated for the conditions when the wind was blowing toward 

the identified nearest exposure point by setting f to 1. 

C/Q = (1) (5×10-6 m-2) (2 m s-1)

-1 = 2.5×10-6 s m-3

This value can be multiplied by the estimated release rate of beryllium from explosive testing at TA-15 

(μg s-1) to estimate the airborne beryllium concentration (μg m-3) at the Royal Crest Trailer Park on East 

Jemez Road in Los Alamos. 

Estimation of Concentrations at Points of Interest 

Concentrations of airborne beryllium at the nearest residence (μg m-3) from each identified beryllium 

operation were estimated by multiplying the estimated release rate (μg s-1) by the applicable relative 

concentration value (s m-3). Results are shown in Table 20-17. The estimated release rate and 

concentration values for BeO powder pressing, V Shop, and SM-39 Shop releases are presented as 6-min, 

30-min, and 8-h average values that would be expected to be reached or exceeded once per year and 

monthly average concentrations that would be expected to be reached or exceeded 5% of the time. For 

the explosive tests at TA-15, the results in Table 20-17 for periods longer than a week are values averaged 

over the periods shown based on 100 shots in a year, each with 0.25-h duration of exposure, that together 

released 10% of the total beryllium reported expended in 1964. For periods shorter than a month, the 

results are values averaged over the periods shown based on one shot, with 0.25-h duration of exposure, 

occurring during the period and releasing 1.25% of the total beryllium reported expended in 1964.
20-20 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20

 

Fig. 20-3. Approximate distance from TA-15, PHERMEX area, to the Royal Crest Trailer Park on East Jemez 

Road in Los Alamos 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20 20-21 

Table 20-17. Results of screening-level assessment of potential airborne beryllium concentrations in residential areas of Los Alamos 

B-Building 

Gun 

Testsa

BeO 

Powder 

Pressing 

V-Shop 

Machining 

1943-48 

V-Shop 

Machining 

1949-53 

SM-39 

Shop 1953 

to 1963 

SM-39 

Shop after 

1963 

PHERMEX 

Explosive 

Testsa

Distance to exposure point (m) 49 140 170 170 960 960 4,500 Relative concentration (s m-3) 1.1×10-2 2.5×10-4 1.1×10-4 1.1×10-4 6.9×10-6 6.9×10-6 2.5×10-6Release rates (μg s-1) for stated averaging periods: 

0.1 h: 33,000 64,000 12,000 610 610 3.7 1,500,000 0.5 h: 6,700 20,000 3,900 190 190 1.2 740,000 8 h: 420 3,600 680 34 34 0.20 46,000 730 h ( 1 month): 140 150 29 1.4 1.4 0.0086 670 

Exposure point concentrations (μg m-3) for stated averaging periods: 

0.1 h: 350c,d 16d 1.4d 0.069d 0.0042 0.000025 3.7d0.5 h: 71c,d 5.1d 0.44d 0.022d 0.0013 0.0000080 1.8d8 h: 4.4b,d 0.90d 0.077d 0.0038 0.00023 0.0000014 0.12d730 h ( 1 month): 1.5d,e 0.038d,e 0.0033 0.00016 0.000010 0.000000059 0.0017 

a Episodic releases b Possible exceedance of OSHA/AEC 8-h time weighted average limit = 2 μg m-3c Possible exceedance of OSHA/AEC ceiling limit = 25 μg m-3d Possible exceedance of USEPA Reference Concentration = 0.02 μg m-3e Possible exceedance of National Emission Standard for ambient air averaged over a 30-d period = 0.01 μg m-3
20-22 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20

Identification of Relevant Toxicologic or Regulatory Benchmarks 

The current OSHA permissible exposure limit (PEL) for occupational exposure to beryllium is 2 μg m-3

(8-h time weighted average). A ceiling limit of 5 μg m-3 must not be exceeded during the work shift, 

except that a 30-minute excursion over the ceiling limit is allowed as long as the air concentration never 

exceeds 25 μg m-3 during the 30-minute period (NIOSH 2003). 

The U.S. Atomic Energy Commission issued “Recommendations for Control of Beryllium Hazards” in 

August 1951 that included three standards: a 2 μg m-3 in plant 8-h average beryllium concentration; a 25 

μg m-3 beryllium air concentration which can never be exceeded; and, a 0.01 μg m-3 monthly average 

concentration at the breathing zone in the neighborhood of a plant handling beryllium (Mitchell and Hyatt 

1957). 

The current USEPA Reference Concentration (RfC) for beryllium is 0.02 μg m-3 (USEPA 2009). The 

RfC is an estimate (with uncertainty spanning an order of magnitude) of a daily inhalation exposure of the 

human population (including sensitive subgroups) that is likely to be without an appreciable risk of 

deleterious effects during a lifetime. The RfC is based on beryllium sensitization and progression to 

chronic beryllium disease (CBD) identified in studies published in 1996 (Kreiss et al. 1996) and 1949 

(Eisenbud et al. 1949). 

The Kreiss et al. (1996) occupational exposure study identified a LOAEL (Lowest Observed Adverse 

Effect Level) for beryllium sensitization in workers exposed to 0.55 μg m-3 (median of average 

concentrations). A cross-sectional study was conducted of 136/139 of the then-current beryllium workers 

in a plant that made beryllia ceramics from beryllium oxide powder. Measurements from 1981 and later 

were reviewed and included area samples, process breathing-zone samples, and personal lapel samples 

(the last year only). The Eisenbud et al. (1949) study, using relatively insensitive screening methods, 

suggests a NOAEL (No Observed Adverse Effect Level) of 0.01-0.1 μg m-3 in community residents living 

near a beryllium plant. The LOAEL from the Kreiss et al. study was used for the operational derivation 

of the RfC because the screening method used in the Eisenbud et al. (1949) study was less sensitive than 

the method used in the Kreiss et al. (1996) study. 

According to the Agency for Toxic Substances and Disease Registry (ATSDR 2002), there is evidence to 

suggest that the occurrence of chronic beryllium disease is not related to duration of exposure and can 

have a long latency period. Very few studies assessing the occurrence of chronic beryllium disease also 

measured airborne beryllium levels. Eisenbud et al. (1949) found no cases of chronic beryllium disease in 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20 20-23

residents living at least 0.75 miles away from a beryllium manufacturing facility. The airborne beryllium 

concentration at this distance was estimated to range from 0.01 to 0.1 μg m-3. 

It is the opinion of the ATSDR that the available database does not support the derivation of acute, 

intermediate, or chronic duration inhalation MRLs (minimal risk levels). Eisenbud et al. (1949) found no 

cases of chronic beryllium disease among community residents chronically exposed to 0.01-0.1 μg m-3 of 

beryllium. The study used relatively insensitive methods to detect chronic beryllium disease, therefore 

it’s not know if the residents exposed to 0.01 μg m-3 of beryllium would test positive for sensitization or 

subclinical chronic disease. No human acute or intermediate duration studies that identify a NOAEL or 

LOAEL for respiratory effects were identified. Animal studies have not identified a reliable NOAEL, and 

the LOAELs are several orders of magnitude higher than the LOAEL from the Kreiss et al. (1996) 

occupational exposure study. Although the critical target of beryllium toxicity has been identified as the 

respiratory tract, an animal model that mimics all aspects of chronic beryllium disease has not been 

identified. Therefore, it is inappropriate to derive inhalation MRLs from the animal data (ATSDR 2002). 

Several studies attempted to associate beryllium sensitization and/or chronic beryllium disease with mean, 

cumulative, and peak exposure levels and duration of employment, but no consistent associations were 

found. Although the data are insufficient for establishment of concentration-response relationships, the 

available occupation exposure studies do provide exposure levels that may result in beryllium 

sensitization. Beryllium sensitization and/or chronic beryllium disease have been detected at exposure 

levels of 0.5 μg m-3. Respiratory disease is not likely to occur from exposure to beryllium levels in the 

general environment because ambient air levels (0.00003–0.0002 μg m-3) are very low (ATSDR 2002). 

Comparison of Estimated Concentrations with Relevant Benchmarks 

The results of the preliminary screening of airborne beryllium concentrations in residential areas of Los 

Alamos, in terms of estimated airborne concentrations over four different averaging periods, are 

represented in Fig. 20-4 along with representations of the regulatory limits that can be applied to 

beryllium concentrations in occupational or public settings. The estimated airborne beryllium 

concentrations that exceeded one or more of those limits are also identified with footnotes in Table 20-17. 

While occupational exposure limits are not directly applicable to exposures of members of the public, 

they are presented as benchmarks to which the calculated concentrations can be compared. Limits 

imposed on exposures to members of the public are generally lower than those imposed on worker 

exposures, so concentrations in residential areas must be maintained lower than those accepted in 

workplace environments. 
20-24 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20

Fig. 20-4. Screening-level estimates of airborne beryllium concentrations in public areas near 

LANL for six historical operations 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20 20-25

Conclusions 

The screening results indicate that the 8-h time weighted average permissible exposure limit of 2 μg m-3

for beryllium adopted for workers by OSHA and the AEC could have been exceeded in residential areas 

by releases from the B-Building gun tests. The OSHA/AEC ceiling limit of 25 μg m-3 for workers could 

also have been exceeded for releases from those tests based on concentrations estimated for 0.5-h and 

0.1-h averaging periods. The USEPA reference concentration of 0.02 μg m-3 could have been exceeded in 

residential areas by releases from B-Building gun testing, BeO powder pressing, V-Shop machining, and 

tests at PHERMEX. The National Emission Standard of 0.01 μg m-3 for beryllium in ambient air 

averaged over a 30-d period could have been exceeded in residential areas from the B-Building gun tests 

and BeO powder pressing. 

References 

ATSDR. Toxicological Profile for Beryllium. Atlanta, GA: Agency for Toxic Substances and Disease 

Registry, U.S. Department of Health and Human Services 2002. 

Eisenbud MR, Watna RC, Dustan RC, Steadman LC, Harris WB, Wolf BS. Non-occupational berylliosis 

Journal of Industrial Hygiene and Toxicology 31: 282-294; 1949. 

Hempelmann LH, Henrickson PW. Transcript of an oral history interview of Dr. Louis Hempelmann 

conducted by Paul Henrickson on 31 January 1986; LANL Archives Collection A-2006-006. 

1986. Repos. No. 8008. 

Kreiss K, Mroz MM, Newman LS. Machining risk of beryllium disease and sensitization with median 

exposures below 2 ug/m3

. American Journal of Industrial Medicine 30: 16-25; 1996. 

LASL. Beryllium memos from LANL Archives Collection A-1984-019, Box 36, Folder 1 Los Alamos 

Scientific Laboratory. 1944. Repos. No. 4975. 

LASL. H-5 Air Sample Data Sheet - Beryllium Shops and Exhaust Los Alamos Scientific Laboratory. 

1969. Repos. No. 7816 

LASL. SD-1 Shop 4 Beryllium Shop 1954-1962 Folder from TA-59 EH&S Records Los Alamos 

Scientific Laboratory. 1970. Repos. No. 7814 

Mitchell RN, Hyatt EC. Beryllium - Hazard Evaluation and Control Covering a Five-Year Study. Los 

Alamos Scientific Laboratory, presented at the American Industrial Hygiene Association 

Meeting. 1957. Repos. No. 1874. 

NCRP. Screening Models for Release of Radionuclides to Atmosphere, Surface Water, and Ground. 

Bethesda, MD: National Council on Radiation Protection and Measurements; NCRP Report No. 

123; 1996. 

NIOSH. Pocket Guide to Chemical Hazards. Washington, DC: National Institute for Occupational Safety 

and Health, Centers for Disease Control and Prevention, Department of Health and Human 

Services; 2003. 

Shipman T. Memorandum dated 16 May 1951 to N. E. Bradbury regarding beryllium toxicity [subject 

redacted]. Los Alamos Scientific Laboratory. 1951. Repos. No. 4723. 
20-26 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 20

Shonka JJ. LAHDRA Project Memo to File: LANL Beryllium Source Terms. Shonka Research 

Associates. 2009. Repos. No. 8009. 

USDOE. DOE Handbook - Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor 

Nuclear Facilities; Volumes I and II. Washington, DC: U.S. Department of Energy; DOE-HDBK3010-94; 1994. 

USDOE. DOE Nuclear Air Cleaning Handbook. Washington, DC: U.S. Department of Energy; HDBK1169-2003; 2003. 

USEPA. Integrated Risk Information System, Beryllium and compounds (CASRN 7440-41-7). 2009. 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 21 21-1

Chapter 21: Public Involvement within the 

 LAHDRA Project

Unlike some dose reconstruction projects that have been conducted, the LAHDRA project team was not 

advised by a committee formed in accordance with the Federal Advisory Committee Act. Public 

meetings were held once or twice each year at various locations in the Los Alamos-Española-TaosPojoaque-Santa Fe region. The meetings included presentations and discussions concerning progress in 

information gathering, knowledge gained about historical activities of relevance to off-site releases, 

problems that were being encountered in accessing and obtaining relevant documents, plans for 

completion of information gathering, and progress toward prioritizing historical releases. Updates on 

noteworthy aspects of project activities were also presented at annual conferences of relevant professional 

societies. 

Postings on the LAHDRA Web site included summaries of all public meeting presentations and 

associated public comments and discussion, summaries of workshops that were conducted to offer more 

detailed overviews of project-related topics for interested parties from LANL and the public, 

downloadable copies of Interim Reports of the project, video clips of excerpts of public meeting 

presentations, and information concerning contacting LAHDRA team members and accessing the project 

document collection and the DocSleuth database at local libraries. CDC and contractor team members 

also met with and offered briefings to representatives of the Eight Northern Pueblo Council and many of 

the individual pueblos in Northern New Mexico. 

Through 2008, there were 15 public meetings and two workshops hosted by CDC and the LAHDRA 

project team. These meetings were held in Pojoaque (6 occasions), Los Alamos (5), Española (3), Santa 

Fe (2), and Taos (1). Eight interim versions of the report of the LAHDRA project were issued as 

information gathering progressed. 

Fig. 21-1. A view of the LAHDRA public meeting in July 2008
21-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 21

Dates and major topics of the meetings are listed 

below, in order of most recent to earliest. 

Summaries of all public meetings and workshops, 

including copies of the presentations and 

paraphrasing of public comments and questions, 

are available on the project Web site at 

http://www.lahdra.org/meetings/meetings.htm

• Wednesday, July 23, 2008 - Project update, 

status of document review 

• Wednesday, July 18, 2007 - Progress in 

document reviews, study of plutonium releases 

in the 1940s and 1950s, public exposures from 

the Trinity test, report updated 

• Wednesday, July 26, 2006 - Project update, status of document review, new database 

• Thursday, June 23, 2005 - Project update, discuss new contract 

• Tuesday, July 27, 2004 - CDC announces completion of work under first LAHDRA contract 

• Tuesday, March 30, 2004 - Release of Draft Interim report. 

• Wednesday, July 9, 2003 - Project update, outlook for continued work 

• Wednesday, July 10, 2002 - Project update, impact of access restrictions 

• Tuesday, November 27, 2001 - Project update, access to records 

• Tuesday, April 24 and Thursday, April 26, 2001 - Project update, access restored, 

document availability 

• Wednesday, September 13, 2000 - Project update, draft report, access issues 

• March 8, 2000 - Project update 

• October 5, 1999 - Interviews with current and retired workers 

• July 27, 1999 - Project update and sample documents 

• February 23, 1999 - Project introduction 

Fig. 21-2. A photographic display presented at 

the July 2008 public meeting 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 22 22-1

Chapter 22: Findings of the LAHDRA Project

The LAHDRA project has significantly expanded the quantity of original documentation that is publicly 

available relevant to past operations at Los Alamos, activities by LANL personnel within New Mexico, 

and the potential for public health effects from past environmental releases. 

The body of information that has been gathered by LAHDRA document analysts is not perfect or 

complete, and the project team was only able to scratch the surface toward careful analysis of its contents. 

Some documents that were generated at LANL will never be found due to their loss or destruction, others 

are difficult or impossible to read because of their age and repeated photocopying, and many of the 

authors and participants from the periods of highest releases have passed away. In spite of these factors, 

the members of the LAHDRA study team believe that enough information exists to reconstruct public 

exposures from the most significant of LANL’s releases to a degree of certainty sufficient to allow health 

professionals to judge if significant elevations of health effects should be expected or measurable. 

For the latter part of the project, some documents containing certain categories of sensitive information 

were withheld from review by LAHDRA analysts. Because documents in these categories included 

nuclear weapon design details, foreign intelligence, and other types of information that are truly not 

relevant to studies of off-site releases or health effects, it does not appear that any information needed for 

dose reconstruction was withheld. The existence of an appeal process by which a federal employee from 

CDC could review withheld documents to verify that they contained no needed information was a key 

consideration in the adoption of that conclusion. And while text was redacted from many selected 

documents prior to public release, LAHDRA analysts had access to original and redacted copies and 

could verify that the redacted text did not contain information that would be needed for dose 

reconstruction. 

The LAHDRA project has been conducted with a high level of transparency, so that interested parties 

could review documents as the team members have selected, perform their own assessments if they so 

choose, and see if they come to the same conclusions. Significant effort was directed to making 

DocSleuth and the LAHDRA collection of over 8,000 documents available to all interested parties in the 

most readily usable fashion. From the beginning of the project, search plans were shared at public 

meetings, and progress reports highlighted significant milestones, accomplishments, and challenges. 

Preliminary prioritization assessments were openly shared, even though there was the possibility that 

information obtained later might prompt revisions of approaches, assumptions, or conclusions. Members 

of the public, activist groups, and LANL personnel were encouraged to comment on the search plans and 

draft work products and make recommendations for refinement or follow-up work. The quality and 
22-2 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 22

utility of the products of the LAHDRA project has been enhanced by this interaction with scientists and 

members of the public. 

The information gathered by the LAHDRA team indicates that airborne releases to the environment from 

Los Alamos operations were significantly greater than has been officially reported or published to the 

scientific community. The preliminary prioritization steps that have been performed within the LAHDRA 

project, while they have been quite simple, have provided information regarding the relative importance 

of past releases of airborne radionuclides, waterborne radionuclides, and chemicals. In general, it has 

been shown that early releases were most important (1940s-1960s) than those that followed, and that 

plutonium was the most important radionuclide in those early years. Airborne activation products from 

accelerator operations were most important after the mid-1970s, and gross alpha-emitting radioactivity 

was important for waterborne releases from the mid-1950s to the mid-1970s. Among chemicals, organic 

solvents as a class were likely most important, followed by TNT and uranium as a heavy metal. 

While prioritization analyses have provided relative rankings of contaminants within categories, the 

preliminary analyses described herein provided no estimates of concentrations to which members of the 

public were exposed, resulting intakes, or doses to members of the public that could be converted to 

estimated health risks or compared to toxicologic benchmarks or decision criteria. Priority Indices based 

on dilution volumes required to be in compliance with maximum allowable effluent concentrations do not 

reflect how uptake factors vary between radionuclides or the decay that occurs between release point and 

the location of potential public exposure. And because of the paucity of details regarding uses and 

releases of chemicals before the 1970s, the preliminary ranking process used for toxic chemicals did not 

incorporate estimates of the fractions of quantities of chemicals that were on-hand or used were available 

for release to the environment or were likely released. 

Within the effort to prioritize past releases from LANL activities, it was possible for the project team to 

advance to screening-level analyses of potential public exposures from airborne releases of plutonium, 

beryllium, tritium, and uranium. While those analyses have yielded information that is relevant to 

evaluation of the potential health significance of the four evaluated materials, it is important to keep in 

mind that screening results are not meant to represent actual doses that were received by members of the 

public or concentrations to which residents could have been exposed. They are meant to support 

decisions concerning whether further investigation of identified releases should be pursued. 

LAHDRA has been almost exclusively an information gathering effort. If estimates of historical 

exposures to members of the public are desired for the releases that have been identified and prioritized 

by the LAHDRA team, it will be necessary to delineate pathways of human exposure that were complete, 

to characterize environmental fate and transport, and to calculate doses and the subsequent health risks to 
DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 22 22-3

groups who were exposed. Methods to perform these steps have been developed and applied for 

numerous other atomic weapons complex sites, but would have added dimensions to properly reflect the 

effects of the complex terrain in which LANL is set and to represent the transport of waterborne releases 

that often soak into dry stream beds before they travel very far, to be transported to a large part by 

occasional high flow events that wash contaminants toward the Rio Grande. 

A number of historical operations have been identified by LAHDRA analysts as areas that might have 

been particularly important in terms of off-site exposures. In addition, critical information gaps have 

been identified in several areas. 

• Early airborne releases of plutonium. Plutonium was processed in crude facilities in D Building 

during World War II, and many roof-top vents were unfiltered and unmonitored. After DP West Site 

took over production late in 1945, there was some filtering of releases, but poor monitoring practices 

caused releases to be underestimated. Documents indicate that DP West releases for 1948-1955 alone 

were over 100-times the total reported by the Lab for operations before 1973. A screening-level 

assessment of public exposures from releases of plutonium in 1949 showed that airborne plutonium 

releases warrant further evaluation. 

• Airborne beryllium releases. Los Alamos used significant quantities of beryllium before the health 

hazards of the material were fully appreciated, and it was processed very close to residential areas. 

Preliminary screening indicated that early beryllium processing could have resulted in concentrations 

in residential areas that exceeded worker exposure limits, the USEPA reference concentration, and the 

National Emission Standard for beryllium. 

• Public exposures from the Trinity test. Residents of New Mexico were not warned before the 1945 

Trinity blast or informed of health hazards afterward, and no residents were evacuated. Exposure 

rates in public areas from the world’s first nuclear explosion were measured at levels 10,000-times 

higher than currently allowed. Residents reported that fallout “snowed down” for days after the blast, 

most had dairy cows, and most collected rain water off their roofs for drinking. All assessments of 

doses from the Trinity test issued to date have been incomplete in that they have not addressed 

internal doses received after intakes of radioactivity through inhalation or consumption of 

contaminated water or food products. 

• Airborne uranium releases. LANL has used uranium since its beginnings in enrichments ranging 

from depleted to highly enriched. It has been machined and fabricated into weapon and reactor 

components and large quantities have been expended in explosive testing. Preliminary screening 

assessments indicate that enriched uranium releases do not warrant high priority in terms of potential 
22-4 DRAFT FINAL REPORT OF CDC’S LAHDRA PROJECT – Chapter 22

health risk, but show that releases of depleted uranium warrant further investigation. None of these 

evaluations, however, consider releases from LANL’s early operations. Early releases could have 

been much larger than those from the 1970s forward, for which effluent data have been summarized. 

Further investigation is needed before a conclusive assessment can be made of potential health risks 

from LANL’s airborne uranium releases. 

• Tritium releases before 1967. Los Alamos used tritium as early as 1944, and received it in 

increasing quantities in the decades that followed for use at ten or more areas of the Lab. In spite of 

this, LANL compilations of effluent data include no tritium releases before 1967. LAHDRA team 

members located scattered documents that describe numerous episodic releases within the 22-year 

period of tritium usage for which official reports of LANL releases include no data for the 

radionuclide. These documents call into question the release estimates reported by LANL for 1967 

forward and indicate that releases before 1967 constitute a data gap that must be addressed if the 

health significance of LANL tritium releases is to be evaluated. 

Based upon the and the information that has been gathered and the findings of the LAHDRA project, 

CDC and other interested parties will judge if the available information indicates that past releases of any 

materials could have been sufficiently high that detailed investigation of past releases and public 

exposures is warranted, and if it appears that sufficient information exists to support detailed investigation 

if the requisite funding could be made available. Potential further investigations that could be undertaken 

for one or more contaminants of highest priority could range from screening level assessments of 

potential public exposures to more rigorous exposure assessments like those that have been conducted for 

other MED/AEC/DOE sites and have become known as dose reconstructions. Unlike the prioritization 

analyses performed to date, these assessments would likely incorporate modeling of environmental 

transport, exposure pathway analysis, and reflection of the uncertainties and variability associated with 

input data, assumptions, and models so that the ranges of exposures received by likely members of the 

public can be specified at a stated level of confidence. Assessments of that type are often performed in an 

iterative fashion, with uncertainty analyses focusing research on components of the assessment that are 

contributing most to the overall uncertainty of results. Further refinement can be directed to those 

elements, and the process repeated until the uncertainty of results is acceptable or cannot be further 

reduced.