August 28, 2006 

Mr. David Staudt 

Centers for Disease Control and Prevention 

Acquisition and Assistance Field Branch 

Post Office Box 18070 

626 Cochrans Mill Road – B-140 

Pittsburgh, PA 15236-0295 

Subject: Contract No. 200-2004-03805, Task Order 1: Los Alamos National Laboratory 

Site Profile Review, SCA-TR-TASK1-0011 

Dear Mr. Staudt: 

SC&A is pleased to submit to NIOSH and the Advisory Board our draft Los Alamos National 

Laboratory Site Profile Review. 

If you have any questions or comments on this report, please contact John Mauro at 732-530-

0104. We look forward to discussing this draft report with NIOSH and the Advisory Board. 

Project Manager 

cc: P. Ziemer, PhD, Board Chairperson A. Makhijani, PhD, SC&A 

Advisory Board Members H. Behling, SC&A 

L. Wade, PhD, NIOSH M. Thorne, SC&A 

L. Elliott, NIOSH H. Chmelynski, SC&A 

J. Neton, PhD, NIOSH J. Fitzgerald, Saliant 

S. Hinnefeld, NIOSH J. Lipsztein, SC&A 

L. Homoki-Titus, NIOSH K. Robertson-DeMers, CHP, Saliant 

A. Brand, NIOSH S. Ostrow, PhD, SC&A 

J. Broehm, NIOSH K. Behling. SC&A 

L. Shields, NIOSH Project File (ANIOS/001/11) 

Sincerely, 

John Mauro, PhD, CHP 

1608 SPRING HILL ROAD, SUITE 400 • VIENNA, VIRGINIA • 22182 • 703.893.6600 • FAX 703.821.8236 
Draft 

ADVISORY BOARD ON 

RADIATION AND WORKER HEALTH 

National Institute of Occupational Safety and Health 

Los Alamos National Laboratory Site Profile Review 

Contract No. 200-2004-03805 

Task Order No. 1 

SCA-TR-TASK1-0011
 

Prepared by 

S. Cohen & Associates 

1608 Spring Hill Road, Suite 400 

Vienna, Virginia 22182 

Saliant, Inc.
 

5579 Catholic Church Road 

Jefferson, Maryland 21755
 

August 2006 

Disclaimer 

This document is made available in accordance with the unanimous desire of the Advisory Board 

on Radiation and Worker Health (ABRWH) to maintain all possible openness in its 

deliberations. However, the ABRWH and its contractor, SC&A, caution the reader that at the 

time of its release, this report is pre-decisional and has not been reviewed by the Board for 

factual accuracy or applicability within the requirements of 42 CFR 82. This implies that once 

reviewed by the ABRWH, the Board’s position may differ from the report’s conclusions. Thus, 

the reader should be cautioned that this report is for information only and that premature 

interpretations regarding its conclusions are unwarranted. 
 

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S. Cohen & Associates: Document No. 

SCA-TR-TASK1-0011 

Technical Support for the Advisory Board on 

Radiation and Worker Health Review of 

Effective Date: 

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NIOSH Dose Reconstruction Program Revision No. 0 – DRAFT 

LOS ALAMOS NATIONAL LABORATORY 

SITE PROFILE REVIEW Page 1 of 213 

Task Manager: 

________________________ Date: ___________ 

Joseph Fitzgerald 

Supersedes: 

N/A 

Project Manager: 

________________________ Date: ___________ 

John Mauro, Ph.D, CHP 
 

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TABLE OF CONTENTS 

Acronyms and Abbreviations ..........................................................................................................6 

1.0 Executive Summary ...........................................................................................................11 

1.1 Summary of Strengths............................................................................................15 

1.2 Summary of Findings.............................................................................................15 

1.3 Opportunities for Improvement .............................................................................19 

2.0 Scope and Introduction ......................................................................................................21 

2.1 Review Scope.........................................................................................................21 

2.2 Review Approach...................................................................................................23 

2.3 Report Organization...............................................................................................23 

3.0 Assessment Criteria and Methods......................................................................................25 

3.1 Objectives ..............................................................................................................25 

3.1.1	 Objective 1: Completeness of Data Sources ..........................................25 

3.1.2	 Objective 2: Technical Accuracy ...........................................................25 

3.1.3	 Objective 3: Adequacy of Data ..............................................................26 

3.1.4	 Objective 4: Consistency Among Site Profiles ......................................26 

3.1.5	 Objective 5: Regulatory Compliance .....................................................26 

4.0	 Site Profile Strengths .........................................................................................................30 

4.1 Completeness of Data ............................................................................................30 

4.2 Adequacy of Data ..................................................................................................31 

4.3 Technical Accuracy/Claimant Favorability ...........................................................32 

4.4 Consistency Among Site Profiles ..........................................................................32 

4.5 Regulatory Compliance .........................................................................................32 

5.0	 Vertical Issues ....................................................................................................................33 

5.1	 Issue 1: Site Profile Does Not Adequately Address Data Insufficiency for 

Impact and Implications to Early Worker Dose Reconstruction ...........................33 

5.1.1	 Background..............................................................................................34 

5.1.2	 External Monitoring of Early Workers....................................................35 

5.1.3	 Internal Monitoring of Early Workers.....................................................36 

5.2	 Issue 2: Inadequate Consideration Has Been Given to Potential Exposure 

and Missed Dose from Other Radionuclides .........................................................38 

5.2.1	 Missed Dose from Other Radionuclides..................................................39 

5.2.2	 Radionuclides with Limited Bioassay Data ............................................40 

5.3	 Issue 3: Special Tritium Compounds Not Adequately Addressed........................42 

5.4	 Issue 4: Dose Estimation Not Addressed for LANL Personnel Assigned to 

Weapons Testing....................................................................................................45 

5.5	 Issue 5: Neutron Dose Reconstruction Approach May Result in 

Underestimated Dose .............................................................................................48 

5.5.1	 Neutron Doses Below 1 MeV and Above 3 MeV of Energy ..................48 

5.5.2	 NIOSH’s Recent Use of Neutron-to-Photon Ratio Values Instead 

of NTA Film Data ...................................................................................49 
 

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5.6	 Issue 6: TBD Does Not Adequately Address Missed Plutonium Internal 

Uptakes Prior to 1970 due to Absence of Lung Counters .....................................53 

5.7	 Issue 7: Completeness and Accuracy of Dosimetry Records Not 

Substantiated..........................................................................................................55 

5.7.1	 Validation of the Database ......................................................................55 

5.7.2	 Radiation Exposure Information in Medical Files ..................................57 

5.7.3	 Human Radiation Experiments................................................................58 

5.8	 Issue 8: TBD does not address Potentially Missed Am-241 Intakes Prior to 

the Mid-1990s ........................................................................................................59 

5.9	 Issue 9: The Internal Dose TBD Lacks a Clear Means to Assign Dose to
 

Unmonitored Workers ...........................................................................................61 

5.10	 Issue 10: The TBD Does Not Adequately Address Potential Dose 

Contribution from External High-Radiation Exposures to Unbadged 

Workers ..................................................................................................................64 

5.11	 Issue 11: Unmonitored Exposures of Zia Company Maintenance, 

Construction, and Facility Support Workers Not Sufficiently Addressed.............68 

5.12	 Secondary Issues....................................................................................................71 

5.12.1	 Secondary Issue 1: Cumulative Effect of Numerous Source Terms 

Not Adequately Addressed......................................................................71 

5.12.2	 Secondary Issue 2: Validation of the LAHDRA Project Data 

Remains in Question................................................................................71 

5.12.3	 Secondary Issue 3: “Ratioing” Approach to Estimate Airborne 

Concentrations is Questionable ...............................................................72 

5.12.4	 Secondary Issue 4: Additional Occupational Medical X-rays
 

should be Included in Dose .....................................................................72 

5.12.5	 Secondary Issue 5: Beam Quality, Filtration, and X-ray Tube 

Output Not Well Known .........................................................................74 

5.12.6	 Secondary Issue 6: Lack of Maintenance, Collimation, and X-ray 

Protocol Data Increase Uncertainty .........................................................74 

5.12.7	 Secondary Issue 7: Less than Optimal Collimation and Uncertain 

Substitute DCFs Impact Dose .................................................................75 

5.12.8	 Secondary Issue 8: Missed Noble Gases and Mixed Activation 

Product Environmental Dose...................................................................76 

5.12.9	 Secondary Issue 9: Lack of Equipment, Beam Quality, and X-ray 

Protocols Impact DCFs............................................................................76 

5.12.10 Secondary Issue 10: A Site-wide Atmospheric Model is needed 

for Accurate Environmental Dose ...........................................................77 

5.12.11 Secondary Issue 11: Frequency and Types of X-ray Exposures are 

Uncertain .................................................................................................77 

5.12.12 Secondary Issue 12: Significant Estimates of Dose are Lacking for 

Some Episodic Releases ..........................................................................78 

6.0	 Overall Adequacy of the Site Profile as a Basis for Dose Reconstruction ........................80 

6.1	 Satisfying the Five Objectives ...............................................................................80 

6.1.1	 Objective 1: Completeness of Data Source ............................................80 

6.1.2	 Objective 2: Technical Accuracy ...........................................................82 

6.1.3	 Objective 3: Adequacy of Data ..............................................................84 
 

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6.1.4 Objective 4: Consistency Among Site Profiles ......................................84 

6.1.5 Objective 5: Regulatory Compliance .....................................................86 

6.2 Usability of Site Profile for Intended Purpose .......................................................86 

6.2.1 Ambiguous Dose Reconstruction Direction ............................................87 

6.2.2 Inconsistencies and Editorial Errors in the Site Profiles .........................88 

6.3 Unresolved Policy or Generic Technical Issues ....................................................88 

References......................................................................................................................................90 

Attachment 1: NIOSH Technical Documents Considered During the Review ............................98 

Attachment 2: Site Expert Interview Summary............................................................................99 

Attachment 3: Key Questions and Responses for NIOSH/ORAU Regarding Site Profile 

Documents .......................................................................................................................132 

Attachment 4: Summary of Conference Call on SC&A Questions Provided to NIOSH ...........162
 

Attachment 5: Supplemental Responses to Action Items from Conference Calls......................181 

Attachment 6: LANL-Sponsored Atmospheric and Underwater Testing...................................192 

Attachment 7: Summary Dose Reconstruction Assumptions and Consistency of 

Assumptions with Other Site Profiles ..............................................................................197 

Attachment 8: Site Expert Comments on the LANL Site Profile ...............................................208 
 

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ACRONYMS AND ABBREVIATIONS 

AA-2 Audits and Assessment Group 

Advisory Board Advisory Board on Radiation and Worker Health 

AP Anterior-Posterior 

AEC Atomic Energy Commission 

AWE Atomic Weapons Employer 

Bq Becquerel 

CAM Continuous Air Monitor 

CDC Centers for Disease Control and Prevention 

CEDE Committed Effective Dose Equivalent 

CFR Code of Federal Regulations 

Ci Curie 

CMR Chemistry and Metallurgy Research 

Cpm Counts per Minute 

DAC Derived Air Concentration 

DARHT Dual Axis Radiographic Hydrodynamics Test 

DCF Dose Conversion Factor 

D&D Decontamination and Decommissioning 

DNAA Delayed Neutron Activation Analysis 

DOD Department of Defense 

DOELAP DOE Laboratory Accreditation Program 

DOL Department of Labor 

DOT Department of Transportation 

DP Defense Programs 

DR Dose Reconstruction/Dose Reconstructor 

DOE Department of Energy 

dpm Disintegrations per Minute 

EEOICPA Energy Employees Occupational Illness Compensation Program Act of 2000 

ESE Entrance Skin Exposure 

FDA Food and Drug Administration 

FMPC Feed Materials Production Center (Fernald) 

FMU Facility Manager Unit 
 

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FOIA Freedom of Information Act 

GM Geometric Means 

GSD Geometric Standard Deviation 

HEPA High Efficiency Particulate Air 

HP Health Physics 

HPTL High Pressure Tritium Laboratory 

HRL Health Research Laboratory 

HT Tritium gas 

HTO Tritiated Water 

HVL Half value layer 

IAAP Iowa Army Ammunition Plant 

IBF Ion Beam Facility 

ICRP International Commission on Radiological Protection 

IMBA Integrated Modules for Bioassay Analysis 

INEEL Idaho National Engineering and Environmental Laboratory 

IREP Interactive RadioEpidemiological Program 

keV Kilo electron Volt 

kVp Kilovolt Peak 

LAHDRA Los Alamos Historical Document Retrieval and Assessment Project 

LAMC Los Alamos Medical Center 

LAMPF Los Alamos Meson Physics Facility 

LANL Los Alamos National Laboratory 

LANSCE Los Alamos Neutron Science Center 

LAPRE Los Alamos Power Reactor Experiment 

LASL Los Alamos Scientific Laboratory 

LAT Lateral 

LLNL Lawrence Livermore National Laboratory 

μCi Microcurie 

MAC Maximum Allowable Concentration 

MCW Mallinckrodt Chemical Works 

MDA Minimum Detectable Activity 

MDL Minimum Detectable Level 
 

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MED Manhattan Engineering District 

MeV Mega-electron Volt 

MFP Mixed Fission Products 

MPBB Maximum Permissible Body Burden 

MPC Maximum Permissible Concentration 

mR Milliroentgen 

mrem Millirem 

MT Metal Tritides 

NCRP National Council on Radiation Protection and Measurements 

n/g Neutron-to-gamma 

n-p Neutron-to-photon 

NIOSH National Institute for Occupational Safety and Health 

NOO Nevada Operations Office 

NTA Eastman Kodak Nuclear Track Film Type A 

NTP Nuclear Track Plate 

NTS Nevada Test Site 

OBT Organically Bound Tritium 

OCAS Office of Compensation Analysis and Support 

OCR Occurrence Reports Collection 

ORNL Oak Ridge National Laboratory 

ORAU Oak Ridge Associated Universities 

ORISE Oak Ridge Institute for Science and Education 

OTIB ORAU Technical Information Bulletin 

OW Open Window 

OWR Omega West Reactor 

PA Posterior-Anterior 

PAS Personal Air Sampling 

PFG Photofluorography 

PHERMEX Pulsed High-Energy Radiographic Machine Emitting X-rays 

PIC Pocket Ionization Chamber 

PNAD Personal Neutron Accident Dosimeter 

POC Probability of Causation 
 

 

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PPE Personnel Protective Equipment 

PPG Pacific Proving Grounds 

ppm Parts Per Million 

PTLA Protection Technology Los Alamos 

P/VAP Particulate and Vapor Activation Products 

R&D Research and Development 

RAM Radiation/Remote Area Monitor 

RCRA Resource Conservation and Recovery Act 

RCT Radiological Control Technician 

REECo Reynolds Electrical Engineering Company 

rem Roentgen Equivalent Man 

RFP Rocky Flats Plant 

RIR Radiation Incident Report 

RWP Radiation Work Permit 

SC&A S. Cohen and Associates 

SCBA Self-contained Breathing Apparatus 

SMT Special Metal Tritides 

SNL Sandia National Laboratory 

SNM Special Nuclear Material 

SOP Standard Operating Procedure 

SRDB Site Research Database 

SRS Savannah River Site 

SSD Source to Surface Distance 

STC Stable tritiated compounds 

TA Technical Area 

TBD Technical Basis Document 

TIB NIOSH Technical Information Bulletin 

TIMS Thermal Ionization Mass Spectrometry 

TLD Thermoluminescent Dosimeter 

TSFF Tritium Science and Fabrication Facility 

TSTA Tritium System Test Assembly 

UPPU Original plutonium workers of the Manhattan Project, the UPPU Club 
 

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UTA Urine Tracking System 

WETF Weapons Engineering Tritium Facility 

Y-12 Plant Y-12 National Security Complex 
 

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1.0 EXECUTIVE SUMMARY 

This report provides the results of an independent audit conducted by S. Cohen and Associates 

(SC&A, Inc.) of the technical basis documents (TBDs) that make up the site profile for the Los 

Alamos National Laboratory (LANL) developed by the National Institute of Occupational Safety 

and Health (NIOSH). This audit was conducted during the period October 18, 2005–July 18, 

2006, in support of the Advisory Board on Radiation and Worker Health (Advisory Board) in the 

latter’s statutory responsibility under the Energy Employees Occupational Illness Compensation 

Program Act of 2000 (EEOICPA) to conduct such reviews and advise the Secretary of Health 

and Human Services on the “completeness and adequacy” of the EEOICPA program. 

Los Alamos National Laboratory (LANL) is owned by the U. S. Department of Energy (DOE) 

and has been managed by the University of California since its establishment in 1943 as part of 

the Manhattan Project’s early efforts to create the first atomic weapons. Management of LANL, 

as of June 1, 2006, has transitioned to Los Alamos National Security, LLC, a new consortium of 

four contractors with the University of California, still managing scientific research. After 

World War II, LANL’s primary mission has been to serve as an experimental facility for 

defense-related programs, and for basic scientific research and development (R&D). The facility 

was Los Alamos Scientific Laboratory (LASL) until 1981. LANL’s responsibilities have 

expanded since the early days to include thermonuclear weapons design, high explosives and 

ordnance development and testing, weapons reactor research, waste disposal, waste incineration, 

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

LANL has performed special functions in its longstanding backup role to Hanford and Rocky 

Flats Plant (RFP). When an accident occurred at the Hanford Plutonium Finishing Plant in 1984, 

plutonium was sent in oxide form to LANL for conversion to metal. In addition, LANL served 

in a backup role for limited periods after major fires in plutonium production facilities at RFP in 

1957 and 1969. Today, LANL operates the only remaining U.S. plutonium pit production 

facility. 

The Introduction TBD, ORAUT-TKBS-0010-1 (Buddenbaum 2005), provides the following 

history on some of LANL’s key operational roles over the years: 

The original main technical area (TA-1) processed plutonium and uranium for the 

World War II devices. TA-1 continued to build and test nuclear weapon critical 

assemblies on a limited scale until the late 1950s. Other radionuclides handled 

on a smaller scale compared with plutonium and uranium included americium, 

polonium, lanthanum, and barium. Starting in 1946, TA-21 (aka DP West and 

DP East) which was built over several years became the primary plutonium and 

uranium processing facilities. In 1978, plutonium and uranium operations were 

moved to TA-55 and the DP sites during the next several years underwent 

decontamination and decommissioning. The Chemistry and Metallurgy Research 

(CMR) at TA-3 processed primarily plutonium, uranium, and americium. 
 

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Omega Site (TA-2) was used for critical assembly experiments and was the site of 

the water boilers, Pu Fast Reactor, a.k.a. Clementine (1946–1950), Omega West 

Reactor (1956–1992), and other reactors for critical experiments that were later 

moved to TA-18 in 1947. Early reactors, built to confirm critical masses for 

fissionable materials and to study properties of fission and the behavior of the 

resultant neutrons, were the forerunners of a variety of reactors designed, and in 

some cases built and operated, at Los Alamos. While some of these reactors 

served as sources of neutrons for various nuclear research or for materials 

testing, other designs related to 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 spacecraft. 

The Los Alamos Neutron Source Center (LANSCE), formerly known as LAMPF 

located at TA-53 is the largest accelerator at LANL. This unit became 

operational in 1972 and still operates today. It has been used for a variety of 

purposes including production of medical isotopes and weapons research. For 

some periods of time, radioactive airborne emissions have accounted for the 

largest boundary doses from all of LANL operations. 

SC&A’s review focused on the six TBDs that make up the LANL site profile. These address 

introduction, site description, internal dose, external dose, occupational medical occupational 

dose, and environmental occupational dose, as they pertain to historic occupational radiation 

exposure of LANL workers. These TBDs were variously issued in 2004–2005. As “living” 

documents, TBDs are constantly being revised as new information, experience, or issues arise. 

For the LANL site profile, in particular, interviews with NIOSH and ORAU staff underscored 

their ongoing and extensive efforts to upgrade the existing TBDs. In that context, SC&A 

discussed with NIOSH (and ORAU) the latter’s dose estimation guidance for LANL that may 

figure in their next TBD revision and would supersede earlier site profile direction. That 

discussion is reflected in several of the SC&A findings in order to add an updated perspective of 

how NIOSH plans to address these issues (notwithstanding that the SC&A review remains based 

on the current TBD editions). 

SC&A’s review process included a review of the TBDs, two onsite visits to conduct interviews 

with site experts and identify documents for data retrieval, reviews of retrieved LANL and other 

historic records, and an exchange of questions and answers, in addition to TBD-specific 

conference calls, between SC&A and its NIOSH and ORAU counterparts. The TBDs were 

evaluated for their completeness, technical accuracy, adequacy of data, compliance with stated 

objectives, and consistency with other site profiles, as stipulated in the SC&A Standard 

Operating Procedure for Performing Site Profile Reviews (SC&A 2004). A complete list of the 

LANL TBDs, as well as supporting documents, that were reviewed by SC&A is provided in 

Attachment 1. 
 

 

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This review was prolonged by the ongoing LANL contract competition that delayed site data 

retrieval during November 2005 to January 2006. It was also necessary to have all interview 

notes and retrieved documents screened by LANL classification reviewers to assure that no 

sensitive material was inadvertently included. 

SC&A found that the site profile made a reasoned effort to cover the broad historic scope, and 

diverse and extensive radiological source terms of LANL’s operational history, but fell 

considerably short, nonetheless; this was particularly so in characterizing and providing 

appropriate dose estimation guidance for the early years (1943 through the 1960s). As observed 

in the Site Description TBD, ORAU-TKBS-0010-2 (Buddenbaum 2004): 

The diversity of lab operations may be second-to-none when compared to other 

sites within the DOE complex. With a few exceptions, most man-made or natural 

radionuclides known to exist have, at one time or another, been present and/or 

processed at LANL. 

SC&A concurs with this conclusion, but is concerned with the TBD’s position that 

This document attempts to highlight those radioactive materials or radiation 

sources that can be tied to particular operations and have been well documented 

over time. As new information becomes available or as claimant information 

requirements change or expand over time, descriptions of other sources of 

radiation at LANL will be added to this document in future revisions. 

(Buddenbaum 2004, pg. 6) 

This admission that the site profile does not address occupational radiation sources beyond the 

more established and well documented ones is problematic given this tremendous diversity, the 

radiological significance of many of these “other” radionuclides, and the steadily evolving nature 

of radiological controls, dosimetry practices, and recordkeeping at the site through the late 

1940s, 1950s, 1960s, and into the 1970s, that may have contributed to information gaps critical 

to dose estimation. 

In this regard, SC&A found that the site profile does not adequately address the central question 

of data insufficiency for its impact and implications to early worker dose reconstruction. 

Information available for dose reconstruction in the early years is limited, inadequate, or in some 

cases, not available. The SC&A review finds that inadequate consideration was given to 

potential exposure and missed dose from radionuclides other than the “well documented” ones 

cited by the TBD (e.g., plutonium polonium, tritium etc.). These “other” radionuclides include 

P-32, Na-24, C-14, N-15, O-18, Np-237, and various fission products that were used in research, 

and various isotopes of americium, curium, thorium, and uranium used in process and recovery 

operations. The internal dosimetry TBD approach is to use data from a later era to assign dose, 

or to apply a hypothetical chronic intake for plutonium, polonium, and uranium when bioassay 

data is unavailable. In most cases at LANL, routine bioassay monitoring was limited to those 

workers programmatically identified as being potentially exposed to internal emitters, which 

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With respect to unmonitored workers, SC&A finds that for a long period extending into the 

1960s, the TBD does not provide a plausible approach for assigning missed internal dose to 

unmonitored LANL workers. Given the historic inadequacies in LANL’s bioassay program even 

into the 1960s and 1970s, it is clear why NIOSH concluded in the TBD that “the experiences of 

workers with monitored intakes cannot be used to develop a scenario [i.e., co-worker model] for 

workers who were not monitored;” but it is less clear how NIOSH intends to “derive potential 

intakes from removable contamination levels, tolerance and MAC air concentration levels, and 

airborne concentrations of significant radionuclides” (Argall 2004). First, such data is not 

necessarily available for many pertinent radionuclides to which workers were exposed and for 

many specific job locations; and second, it is not clear, as emphasized by the TBD itself, who 

may have been exposed to potential internal source terms, given the paucity of radiation controls 

at the site and lack of routine bioassaying of potentially exposed workers that existed well into 

the 1960s and 1970s. Likewise, dose estimation for certain workers, who had site-wide access 

and were in close proximity to a broad range of radiation exposure sources (e.g., laboratory 

support workers from the Zia Company and LANL security guards), may be problematic. This 

would be true in such cases where workers were not monitored or were inadequately monitored 

for the exposure they received. 

SC&A is similarly concerned about the stated approach in the Occupational External Dose TBD, 

ORAUT-TKBS-0010-6 (Widner 2005) of assigning doses from the median values of co-workers 

or missed annual doses based on minimum detectable level (MDL) values (in the 100s of mrem 

range) to unmonitored workers, when LANL’s operational history is replete with instances 

where the potential existed for exposures in the rem/hr range. Assignment of the median 

gamma and derived neutron doses from neutron-to-photon (n-p) ratio values, as recommended 

by the TBD, may lead to underestimating an unmonitored worker’s dose where the potential 

existed for exposure to these sources of radiation. 

From the information in the current Occupational External Dose TBD, it is not obvious that the 

dose reconstructor has sufficiently detailed correction factors and instructions available to correct 

for the unmonitored neutron doses resulting from neutrons with less than 1 MeV of energy at the 

numerous facilities at LANL that produced neutron exposures through the years. Only a brief 

reference is made to neutron-gamma comparisons in the dose reconstruction guidelines in 

Appendix E on page 71 (Widner 2005), in reference to unmonitored neutron dose. NIOSH has 

recently commented on its intent to use n-p ratio values instead of the Eastman Kodak Nuclear 

Track Film Type A (NTA) film dose data for neutron dose estimation. If this method is used, 

then the photon doses and the n-p ratio values used will need to be verified. 

SC&A’s review of the LANL dosimetry records cited in the site profile from the standpoint of 

their adequacy and completeness, as well as their inclusion of known sources of LANL worker 

radiation dose information, indicates some gaps that need to be addressed. For example, total 

reliance on the LANL Bioassay Repository database, for which verification and validation has 

only been partially completed, may raise questions regarding the completeness and accuracy of 

internal dose estimates. 
 

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Likewise, it is not clear whether and how radiation dose data were collected and recorded for 

LANL employees participating in nuclear test activities at Trinity, the Pacific Proving Grounds 

(PPG), Nevada Test Site (NTS), and Amchitka. LANL was responsible for monitoring at the 

Trinity test and tests at the PPG. The NTS provided dosimetry support to LANL personnel 

present for testing. The significance and potential dose contribution from LANL personnel 

participation in weapons and safety testing have not been considered in the site profile, nor has it 

been established how (or whether, in all cases) these recorded doses were integrated into LANL 

personnel dose records. 

Issues presented in this report are sorted into the following categories, in accordance with 

SC&A’s review procedures: 

(1) Completeness of data sources 

(2) Technical accuracy 

(3) Adequacy of data 

(4) Consistency among site profiles 

(5) Regulatory compliance 

Following the introduction and a description of the criteria and methods employed to perform the 

review, the report discusses the strengths of the TBD, followed by a description of the major 

issues identified during our review. The issues were carefully reviewed with respect to the five 

review criteria. Several of the issues were designated as primary findings because they represent 

key deficiencies in the TBDs that need to be corrected, and which have the potential to 

substantially impact at least some dose reconstructions. Others have been designated “secondary 

findings” to both connote their importance for the technical adequacy and completeness of the 

site profile, and to indicate that they have been judged by SC&A to have relatively less influence 

on dose reconstruction or the ultimate significance of worker doses so estimated. 

1.1 SUMMARY OF STRENGTHS 

The NIOSH/ORAU team is aware of gaps in the TBDs and has plans to update some of the 

TBDs based on new information gathered since the site profile’s issuance. The NIOSH/ORAU 

team expects to get access to nine additional boxes of LANL documents (approximately 5,000 

documents) and review these documents for their applicability to occupational dose 

reconstruction. The documents contained in these boxes are currently under review for the 

LAHDRA project and will be made available to the EEOICPA by the end of June 2006. There 

will be substantial updates to the Internal Dose TBD (Argall 2004) and the External TBD 

(Widner 2005). 

1.2 SUMMARY OF FINDINGS 

Finding 1: Site profile does not adequately address data insufficiency for impact and 

implications to early worker dose reconstruction. Information available for dose 

reconstruction in the early years is limited, inadequate, or in some cases not available. The 

internal dosimetry TBD approach is to use data from a later era to retrospectively assign dose, or 

to apply a hypothetical chronic intake for plutonium, polonium, and uranium when bioassay data 
 

 

 

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is unavailable. Bioassay monitoring was typically limited to workers directly handling 

radionuclides, or as was often the case in the early years, had not yet been developed. Internal 

monitoring data for many radionuclides handled are not available until as late as the 1960s. The 

current TBD does not consider potential internal dose from radionuclides other than plutonium 

and polonium, for which bioassay data was available during the 1943–1946 timeframe. The 

incompleteness of external dosimetry records and the lack of adequate documentation regarding 

job categories and assignments raise questions regarding the feasibility of assigning co-worker or 

average doses. Likewise, the lack of complete photon dosimetry data in the early days brings 

into question the ability to compute neutron dose by using the n-p ratio method, an approach that 

has been proposed by NIOSH. 

Finding 2: Inadequate consideration has been given in the site profile to potential exposure 

and missed dose from secondary radionuclides. Numerous radionuclides were handled at 

LANL ranging in quantities from fractions of a gram to kilograms. Exposure to a number of 

these radionuclides was not given adequate, or in some cases, any consideration in the internal 

dosimetry TBD, although some are listed as facility-specific radionuclides handled in particular 

technical areas. The dose reconstructor was directed to rely on the claimant interviews for 

identification of potential exposure to non-traditional radionuclides (i.e., other than plutonium, 

uranium, tritium, and polonium). Other radionuclides handled at LANL included radium, 

thorium, actinium, protactinium, americium, neptunium, curium, lanthanum, barium, yttrium, 

and other fission products; and alpha emitters and beta emitters associated with accelerator 

production and weapons development. Inadequate guidance is given for assignment of dose 

from Sr-90, Cs-137, Ba/La-140, P-32, C-14, Pa-231, radioiodine, tritides, and thorium. No clear 

guidance is provided on dose estimation for radium, actinium, neptunium, curium, yttrium, 

tantalum, and radionuclides created as a part of the medical isotope program. 

Finding 3: Dose estimation is not addressed for LANL personnel assigned to weapons 

testing. Exposure conditions related to LANL personnel participation in weapons and safety 

testing have not been considered in the LANL site profile. LANL sponsored numerous nuclear 

weapons tests, including atmospheric, underwater, and underground testing in the U.S. and at the 

PPG. Groups of LANL personnel were present at testing of LANL designed weapons and 

weapons components. LANL was responsible for monitoring at the Trinity test and for tests at 

the PPG. The NTS provided dosimetry support to LANL personnel present for testing. The 

significance and potential dose contribution from LANL personnel participation in weapons and 

safety testing has not been considered in the site profile, nor has it been established how (or 

whether, in all cases) these recorded doses were integrated into LANL personnel dose records. 

The NTS site profile has not been referenced for determination of missed dose at the test site 

itself. No TBDs currently exist to provide background information and guidance on how to 

assess potential missed dose at Trinity, Amchitka, or the PPG. The exposure conditions during 

these activities will differ from those received at the LANL site itself, and should be specifically 

addressed. 

Finding 4: Neutron dose reconstruction approach in TBD may result in underestimated 

dose. The current external dose TBD (Widner 2005) addresses neutron dose reconstruction 

using the NTA film dose data, and provides some correction factors and instructions for doing 
 

 

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so. While some facility-specific neutron energy bands are provided in the TBD (e.g. on pages 47 

and 72), in some facilities, the entire spectrum is essentially below the practical 1-MeV detection 

limits of NTA film used in the workers’ badges. It is not clear that the dose reconstructor would 

have sufficiently detailed correction factors or instructions to correct for the unmonitored neutron 

doses resulting from neutrons with less than 1 MeV of energy at the numerous facilities at LANL 

that produced neutron exposures through the years. 

Furthermore, NIOSH has recently recommended using n-p ratio values instead of the NTA film 

dose data for neutron DR. If this method is used, then the photon doses and the n-p ratio values 

used would need to be verified. It will be difficult to find statistically valid photon dose values 

during 1943 to 1949 since relatively few workers were badged and a significant number of the 

results for those that were badged were not recorded and retained for future use. Additionally, 

dependable n-p ratio values will be difficult to obtain and verify as applicable to the many 

difference exposure conditions that existed in the early years. 

Finding 5: TBD does not adequately address missed plutonium internal doses prior to 1970 

due to absence of lung counters. Many of the workers prior to the early 1970s were not lung 

counted, since lung counters were first developed for LANL monitoring in that timeframe. This 

may lead to uptakes that were never detected or monitored. Section 5.2.1 of the TBD provides a 

section on “Missed Intakes” (Buddenbaum 2004, pg. 14); however, it does not adequately 

describe the approach NIOSH intends to use to reconstruct a claimant-favorable dose for those 

individuals. Subsequent discussions with NIOSH regarding their intention to apply a dose of 

approximately one-third of the average internal dose of workers enrolled in the “UPPU” club (a 

group of volunteers who have regularly submitted urine samples for plutonium bioassay over the 

years) raises the concern that this assumed value is much less than the sensitivity of bioassay 

techniques in place and therefore would not be claimant favorable. 

Finding 6: Completeness and accuracy of dosimetry records are not substantiated. 

SC&A review of the LANL dosimetry records cited in the site profile from the standpoint of 

their adequacy and completeness, as well as their inclusion of known sources of LANL worker 

radiation dose information indicate some gaps that need to be addressed. For example, total 

reliance on the LANL Bioassay Repository database, for which verification and validation has 

only been partially completed, may raise questions regarding the completeness and accuracy of 

internal dose estimates. It was also found that radiological information included in available 

individual worker medical files, including hazard reports, whole body and extremity dose 

information, nasal count data, personnel exposure record – airborne contamination reports, and 

incident reports, all represent useful data that need to be reflected in dose reconstruction. 

Similarly, some LANL workers participated in human radiation experiments up through the 

1960s and should be given credit for radiation doses recorded in those records. Finally, while 

accidents and incidents are listed in the site profile, the site profile does not adequately address 

the significance of such incidents, how they may have contributed to worker dose, and how they 

would be addressed by dose reconstruction. 

Finding 7: TBD does not address potentially missed Am-241 intakes prior to the mid1990s. The dose contribution of Am-241 in-growth within the body after uptake of plutonium 
 

 

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could be significant. The Occupational Internal Dose TBD, ORAUT-TKBS-0010-5 (Argall 

2004) states in Section 5.2.2, page 22, that “there is an indication that workers participated in the 

americium bioassay program only if there was a potential of exposure to pure americium.” Thus, 

many plutonium workers unmonitored for americium may have significant missed dose that 

needs to be closely evaluated by job categories and locations if claimant-favorable americium 

doses from plutonium uptakes are to be calculated during the dose reconstruction process. 

Finding 8: Internal dose TBD lacks a clear means to assign dose to unmonitored workers. 

Given the historic inadequacies in LANL’s bioassay program even into the 1960s and 1970s, it is 

clear why NIOSH concluded in the Occupational Internal Dose TBD (Argall 2004) that “the 

experiences of workers with monitored intakes cannot be used to develop a scenario [i.e., coworker model] for workers who were not monitored;” but it is less clear how NIOSH intends to 

“derive potential intakes from removable contamination levels, tolerance and MAC air 

concentration levels, and airborne concentrations of significant radionuclides” (Argall 2004). 

First, such data is not necessarily available for many pertinent radionuclides to which workers 

were exposed (e.g., both primary and secondary radionuclides) and for many specific job 

locations; second, it is not clear, as emphasized by the TBD itself, who may have been exposed 

to potential internal source terms given the paucity of radiation controls at the site and lack of 

routine bioassaying of potentially exposed workers that existed well into the 1960s and 1970s; 

and third, the TBD is speculative about whether bioassay was performed for short-term workers, 

such as students and postdoctoral researchers. SC&A finds that for a long period extending into 

the 1960s, the TBD (Argall 2004) does not provide a plausible approach for assigning missed 

internal dose to unmonitored LANL workers, nor does it appear to be plausible to do so except 

for a few select radionuclides, such as plutonium and polonium. 

Finding 9: TBD does not adequately address potential dose contribution from external 

high-radiation exposures to unbadged workers. SC&A is concerned regarding the stated 

approach in the Occupational External Dose TBD, ORAUT-TKBS-0010-6 (Widner 2005) of 

assigning doses from the median values of co-workers or missed annual doses based on MDL 

values (in the 100s of mrem range) to unmonitored workers, when LANL’s operational history is 

replete with instances where the potential existed for exposures in the rem/hr range. Sources 

and incidents that likely contribute to the potential for high exposures are not always adequately 

addressed and the resulting doses accounted for in the TBD. Sources of relatively high radiation 

fields that represented a significant potential for worker radiation exposure are not thoroughly 

discussed. Some examples include the following: early experimental accelerators and n-p 

sources; the reactors and the Omega Stack at TA-2 (Omega Site); the radioactive lanthanum 

experiments; the pulsed high-energy x-ray machines, the operations at LAPRE I and II; the spent 

fuel/hot cell operations; and neutron doses in and surrounding TA-18 (Pajarito Laboratory) 

during critical assembly operations. Assignment of the median gamma, and derived neutron 

doses from n-p ratio values, as recommended by the TBD, would lead to underestimating an 

unmonitored worker’s dose that had the potential of exposure to these sources of radiation. 

Finding 10: Unmonitored exposures of Zia Company maintenance, construction, and 

facility support workers, as well as LANL security guards, not sufficiently addressed. The 

Zia Company was the principal subcontractor to LANL from 1946 to June 1986. During this 
 

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timeframe, approximately 15,000 workers were employed to provide a broad range of site-wide 

maintenance, construction, janitorial, waste management, and facility support activities, much of 

it involving potential radiation exposure. While the internal dose TBD provides cursory 

information regarding Zia employees (e.g., on page 12, Table 5A-11 is referenced as providing a 

list of criteria and bioassay exempt job categories for plutonium bioassay), little information is 

provided regarding what is characterized in the TBD as a “separate” monitoring program. This 

is of particular concern, because Zia workers were involved in almost all of the radiological 

operations at the laboratory during most of its history, and were frequently called upon to 

conduct jobs involving potentially significant internal and external radiation exposure potential 

including decontamination, radioactive waste disposal, and “hot” maintenance. While the Zia 

monitoring program later had a computer program that “locked out” (i.e., administratively 

restricted) access to plutonium areas for workers not bioassayed within 425 days, it is not clear 

from the TBD when this program was enacted, and how this measure would have precluded 

workers from receiving uptakes and discontinuing employment or moving to other radiological 

areas and therefore not be bioassayed. The site profile does not provide the requisite basis for 

determining what the potential missed and unmonitored dose may have been for the Zia 

workforce given the spectrum of radiation sources involved. Similar concerns apply to how dose 

estimation will be handled for unmonitored or inadequately monitored LANL security guards 

who likewise had site-wide access and were frequently in locations where potential internal and 

external radiation exposures were likely. 

1.3 OPPORTUNITIES FOR IMPROVEMENT 

(1) Based on the March 21, 2006, conference call with NIOSH on external dosimetry (see 

Attachment 4), NIOSH intends to reissue the Occupational External Dose TBD, 

ORAUT-TKBS-0010-6 (Widner 2005), after input from Dr. Ken Silver (a LANL site 

expert) has been carefully studied and after SC&A concerns have been reviewed and 

resolved, where possible. During the conference call, it was learned that ORAU plans to 

revise all sections based on the review outcomes. 

(2) There is an inconsistency in the collective doses reported by LANL and those reported to 

DOE in annual dose reports. The numbers used in the LANL site profile were based on 

a 2004 internal LANL document that bears no “LA -” technical report number. As noted 

in comments submitted by Dr. Silver (Silver 2005, pg. 42 and Figure 2), many times 

these collective doses were lower than those reported to DOE. 

(3) There are several areas for improvement in regards to what appears in the External Dose 

TBD, ORAUT-TKBS-0010-6 (Widner 2005) to be an over-simplification of important 

issues that could impact dose reconstruction. The three main issues are: 

• 	 Lack of dose measurements and their associated records (especially in the 

early years). 

• 	 Sources of high exposure potential and their affects on unmonitored and 

missed doses. 
 

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• 	 Validation of n-p ratio values and the reliability of the photon doses; both 

of which will be used in neutron DR. 

(4) The current version of the Occupational Environmental Dose TBD, ORAUT-TKBS0010-4 (Cehn and McDowell-Boyer 2004), was published with various gaps in 

information before 1971. NIOSH has advised this was done to allow processing of 

selected LANL claims. 
 

 

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2.0 SCOPE AND INTRODUCTION 

The review of the Los Alamos National Laboratory (LANL) Site Profile was conducted from 

October 18, 2005 – July 18, 2006, by a team of SC&A health physicists and technical personnel. 

2.1 REVIEW SCOPE 

Under the Energy Employees Occupational Illness Compensation Program Act of 2000 

(EEOICPA) and Federal regulations defined in Title 42, Part 82, Methods for Radiation Dose 

Reconstruction Under the Energy Employees Occupational Illness Compensation Program, of 

the Code of Federal Regulations (42 CFR Part 82), the Advisory Board on Radiation and Worker 

Health (Advisory Board) is mandated to conduct an independent review of the methods and 

procedures used by the National Institute for Occupational Safety and Health (NIOSH) and its 

contractors for dose reconstruction. As a contractor to the Advisory Board, S. Cohen and 

Associates (SC&A, Inc.) has been charged under Task 1 to support the Advisory Board in this 

effort by independently evaluating a select number of site profiles that correspond to specific 

facilities at which energy employees worked and were exposed to ionizing radiation. 

This report provides a review of the following six documents related to historical occupational 

exposures at Los Alamos National Laboratory: 

• ORAUT-TKBS-0010-1, Technical Basis Document for Los Alamos National Laboratory 

– Introduction, Rev. 00 (Buddenbaum 2005); 

• ORAUT-TKBS-0010-2, Technical Basis Document for Los Alamos National Laboratory 

– Site Description, Rev. 00 (Buddenbaum 2004); 

• ORAUT-TKBS-0010-3, Technical Basis Document for Los Alamos National Laboratory 

– Occupational Medical Dose, Rev. 00 (Johnson 2004); 

• ORAUT-TKBS-0010-4, Technical Basis Document for Los Alamos National Laboratory 

– Occupational Environmental Dose, Rev. 00 (Cehn and McDowell-Boyer 2004); 

• ORAUT-TKBS-0010-5, Technical Basis Document for Los Alamos National Laboratory 

– Occupational Internal Dose, Rev 00 (Argall 2004); 

• ORAUT-TKBS-0010-6, Technical Basis Document for Los Alamos National Laboratory 

– Occupational External Dose, Rev. 00 (Widner 2005). 

These documents are supplemented by technical information bulletins (TIBs), which provide 

additional guidance to the dose reconstructor. A complete list of these documents is available in 

Attachment 1. 

Implementation guidance is also provided by so-called “workbooks,” which have been 

developed by NIOSH for selected sites to provide more definitive direction to the dose 

reconstructors on how to interpret and apply the technical basis documents (TBDs), as well as 

other available information. 
 

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Beyond the conduct of its independent interviews of site experts and former workers, the SC&A 

team is aware of and has requested access to a NIOSH database named “WISPR,” which 

contains NIOSH/ORAU-conducted worker interviews. It was the team’s understanding that use 

of the database requires training to be provided by ORAU. A formal request has been made for 

training and access to the database. In the meantime, SC&A has reviewed available worker 

input from worker outreach meetings, public comments from the Santa Fe Advisory Board 

meeting in 2002, and comments submitted by Dr. Ken Silver of East Tennessee State 

University. These references are sources of information for the WISPR databases. An 

addendum to this report will be provided based on the results of an evaluation of the information 

found in the WISPR database as necessary. 

SC&A, in support of the Advisory Board, has critically evaluated the LANL Site TBDs in order 

to: 

• 	 Determine the completeness of the information gathered by NIOSH in behalf of the site 

profile with a view to assessing its adequacy and accuracy in supporting individual dose 

reconstructions 

• 	 Assess the technical merit of the data/information 

• 	 Assess NIOSH’s use of the data in dose reconstructions 

SC&A’s review of the six TBDs focuses on the quality and completeness of the data that 

characterized the facility and its operations and the use of these data in dose reconstruction. The 

review was conducted in accordance with Standard Operating Procedure for Performing Site 

Profile Reviews (SC&A 2004), which was approved by the Advisory Board. 

The review is directed at “sampling” the site profile analyses and data for validation purposes. 

The review does not provide a rigorous quality control process whereby actual analyses and 

calculations are duplicated or verified. The scope and depth of the review are focused on aspects 

or parameters of the site profile that would be particularly influential in deriving dose 

reconstructions, bridging uncertainties, or correcting technical inaccuracies. This review does 

not explicitly address the issue of radiation exposures to cleanup workers and decommissioning 

workers, as that is not addressed in the TBDs. 

The six TBDs serve as site-specific guidance documents used in support of dose reconstructions. 

These site profiles provide the health physicists who conduct dose reconstructions on behalf of 

NIOSH with consistent general information and specifications to support their individual dose 

reconstructions. This report was prepared by SC&A to provide the Advisory Board with an 

evaluation of whether and how the TBDs can support dose reconstruction decisions. The criteria 

for evaluation include whether the TBDs provide a basis for scientifically supportable dose 

reconstruction in a manner that is adequate, complete, efficient, and claimant favorable. 

Specifically, these criteria were viewed from the lens of whether dose reconstructions based on 

the TBDs would provide for robust compensation decisions. 
 

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The basic principle of dose reconstruction is to characterize the radiation environments to which 

workers were exposed and determine the level of exposure the worker received in that 

environment through time. The hierarchy of data used for developing dose reconstruction 

methodologies is dosimeter readings and bioassay data, co-worker data and workplace 

monitoring data, and process description information or source term data. 

2.2 REVIEW APPROACH 

SC&A’s review of the TBDs and supporting documentation concentrated on determining the 

completeness of data collected by NIOSH, the adequacy of existing LANL personnel and 

environmental monitoring data, and the evaluation of key dose reconstruction assumptions. 

2.3 REPORT ORGANIZATION 

In accordance with directions provided by the Advisory Board and with site profile review 

procedures prepared by SC&A and approved by the Advisory Board, this report is organized into 

the following sections: 

(1) Executive Summary 

(2) Scope and Introduction 

(3) Assessment Criteria and Method 

(4) Site Profile Strengths 

(5) Vertical Issues and Secondary Issues 

(6) Overall Adequacy of the LANL Site Profile as a Basis for Dose Reconstruction. 

Based on the issues raised in each of these sections, SC&A prepared a list of findings, which are 

provided in the executive summary. Issues are designated as findings if SC&A believes that they 

represent deficiencies in the TBD that need to be corrected and which have the potential to have 

a substantial impact on at least some dose reconstructions. Issues can also be designated as 

Secondary Issues if they simply raise questions, which, if addressed, would further improve the 

TBDs and may possibly reveal deficiencies that will need to be addressed in future revisions of 

the TBDs. 

Many of the issues that surfaced in the report correspond to more than one of the major 

objectives (i.e., strengths, completeness of data, technical accuracy, consistency among site 

profiles, and regulatory compliance). Section 6.0 provides in summary form a list of the issues, 

and to which objective the particular issue applies. Attachment 7 provides a more in-depth 

analysis of the consistency between site profiles. 

The TBDs, in many ways, have done a successful job in addressing a series of technical 

challenges. In other areas, the TBDs exhibit shortcomings that may influence some dose 

reconstructions in a substantial manner. Major issue areas include the following: 

• Insufficient data for early worker dose reconstructions. 
 

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• 	 Inadequate consideration of missed dose to other radionuclides not as well characterized 

or monitored. 

• 	 Exposure to tritium compounds that are not fully addressed in the TBDs. 

• 	 Dose estimates not developed for unmonitored LANL personnel at the atmospheric and 

underground nuclear testing, particularly for potential internal intakes. 

• 	 Underestimation of neutron dose when using NTA file and in developing n-p ratios 

where the initial photon dose is not well characterized. 

• 	 Missed uptakes in period prior to the implementation of lung counting. 

• 	 Areas of completeness and gaps in the availability of dosimetry data, and the adequacy of 

the data that are available. This includes the lack of validation of the LANL database, 

radiation information lacking from the medical records, and exposure received by LANL 

workers during the human radiation experiments. 

• 	 Need to include in the dose reconstructions, the in-growth of Am-241 that may have been 

missed prior to the mid-1990s. 

• 	 Potential missed dose for workers involved in radiation experiments at LANL. 

• 	 Lack of data, particularly in the early days, of the type of x-ray equipment used, the beam 

quality, and the x-ray protocols that impact the dose conversion factors (DCFs). 

• 	 Lack of data to properly document the frequency of chest x-rays and other occupationally 

related x-rays. 

• 	 The lack of a site-wide atmospheric model for determination of environmental dose. 

• 	 Missed dose from episodic releases that often were not fully documented. 

SC&A believes that these important issues need to be effectively dealt with in any upcoming 

revisions to the LANL site profile TBDs in order that more claimant-favorable dose 

reconstructions can be effectively conducted in areas where these data gaps exist. 
 

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3.0 ASSESSMENT CRITERIA AND METHODS 

S. Cohen and Associates (SC&A, Inc.) is charged with evaluating the approach set forth in the 

site profiles that is used in the individual dose reconstruction process. These documents are 

reviewed for their completeness, technical accuracy, adequacy of data, consistency with other 

site profiles, and compliance with the stated objectives, as defined in SC&A Standard Operating 

Procedure for Performing Site Profile Reviews (SC&A 2004). This review is specific to the 

LANL Site Profile, supporting TIBs, and dose reconstruction worksheets; however, items 

identified in this report may be applied to other facilities, especially facilities with similar source 

terms and exposure conditions. The review identifies a number of issues and discusses the 

degree to which the site profile fulfills the review objectives delineated in SC&A’s site profile 

review procedure. 

3.1 OBJECTIVES 

SC&A reviewed the site profile with respect to the degree to which technically sound judgments 

or assumptions are employed. In addition, the review identifies assumptions by NIOSH that give 

the benefit of the doubt to the claimant. 

3.1.1 Objective 1: Completeness of Data Sources 

SC&A reviewed the site profile with respect to Objective 1, which requires SC&A to identify 

principal sources of data and information that are applicable to the development of the site 

profile. The two elements examined under this objective include: (1) determining if the site 

profile made use of available data considered relevant and significant to the dose reconstruction, 

and (2) investigating whether other relevant/significant sources are available but were not used in 

the development of the site profile. For example, if data are available in site technical reports or 

other available site documents for particular processes, and if the TBDs have not taken into 

consideration these data where it should have, this would constitute a completeness of data issue. 

The ORAU site profile document database, including the referenced sources in the TBDs, was 

evaluated to determine the relevance of the data collected by NIOSH to the development of the 

site profile. Additionally, SC&A evaluated records publicly available relating to the LANL site 

and records provided by site experts. 

3.1.2 Objective 2: Technical Accuracy 

SC&A reviewed the site profile with respect to Objective 2, which requires SC&A to perform a 

critical assessment of the methods used in the site profile to develop technically defensible 

guidance or instruction, including evaluating field characterization data, source term data, 

technical reports, standards and guidance documents, and literature related to processes which 

occurred at LANL. The goal of this objective is to first analyze the data according to sound 

scientific principles, and then to evaluate this information in the context of compensation. If, for 

example, SC&A found that the technical approach used by NIOSH was not scientifically sound 

or claimant favorable, this would constitute a technical accuracy issue. 
 

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3.1.3 Objective 3: Adequacy of Data 

SC&A reviewed the site profile with respect to Objective 3, which requires SC&A to determine 

whether the data and guidance presented in the site profile are sufficiently detailed and complete 

to conduct dose reconstruction, and whether a defensible approach has been developed in the 

absence of data. In addition, this objective requires SC&A to assess the credibility of the data 

used for dose reconstruction. The adequacy of the data identifies gaps in the facility data that 

may influence the outcome of the dose reconstruction process. For example, if a site did not 

monitor all workers exposed to neutrons who should have been monitored, this would be 

considered a gap and thus an inadequacy in the data. 

3.1.4 Objective 4: Consistency Among Site Profiles 

SC&A reviewed the site profile with respect to Objective 4, which requires SC&A to identify 

common elements within site profiles completed or reviewed to date, as appropriate. In order to 

accomplish this objective, the LANL TBD was compared to several of the sites already reviewed 

by SC&A. A detailed analysis of this review is provided in Attachment 7. 

3.1.5 Objective 5: Regulatory Compliance 

SC&A reviewed the site profile with respect to Objective 5, which requires SC&A to evaluate 

the degree to which the site profile complies with stated policy and directives contained in 

42 CFR Part 82. In addition, SC&A evaluated the TBD for adherence to general quality 

assurance policies and procedures utilized for the performance of dose reconstructions. 

In order to place the above objectives into the proper context as they pertain to the site profile, it 

is important to briefly review key elements of the dose reconstruction process, as specified in 

42 CFR Part 82. Federal regulations specify that a dose reconstruction can be broadly placed 

into one of three discrete categories. These three categories differ greatly in terms of their 

dependence on and the completeness of available dose data, as well as on the 

accuracy/uncertainty of data. 

Category 1: Least challenged by any deficiencies in available dose/monitoring data are dose 

reconstructions for which even a partial assessment (or minimized dose(s)) corresponds to a 

probability of causation (POC) value in excess of 50%, and assures compensability to the 

claimant. Such partial/incomplete dose reconstructions with a POC greater than 50% may, in 

some cases, involve only a limited amount of external or internal data. In extreme cases, even a 

total absence of a positive measurement may suffice for an assigned organ dose that results in a 

POC greater than 50%. For this reason, dose reconstructions in behalf of this category may only 

be marginally affected by incomplete/missing data or uncertainty of the measurements. In fact, 

regulatory guidelines recommend the use of a partial/incomplete dose reconstruction, the 

minimization of dose, and the exclusion of uncertainty for reasons of process efficiency, as long 

as this limited effort produces a POC of greater than or equal to 50%. 

Category 2: A second category of dose reconstruction is defined by Federal guidance, which 

recommends the use of “worst-case” assumptions. The purpose of worst-case assumptions in 
 

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dose reconstruction is to derive maximal or highly improbable dose assignments. For example, a 

worst-case assumption may place a worker at a given work location 24 hours per day and 365 

days per year. The use of such maximized (or upper bound) values, however, is limited to those 

instances where the resultant maximized doses yield POC values below 50%, which are not 

compensated. For this second category, the dose reconstructor needs only to ensure that all 

potential internal and external exposure pathways have been considered. 

The obvious benefit of worst-case assumptions and the use of maximized doses in dose 

reconstruction is efficiency. Efficiency is achieved by the fact that maximized doses avoid the 

need for precise data and eliminates consideration for the uncertainty of the dose. Lastly, the use 

of bounding values in dose reconstruction minimizes any controversy regarding the decision not 

to compensate a claim. 

Although simplistic in design, to satisfy this type of a dose reconstruction, the TBD must, at a 

minimum, provide information and data that clearly identify: (1) all potential radionuclides, 

(2) all potential modes of exposure, and (3) upper limits for each contaminant and mode of 

exposure. Thus, for external exposures, maximum dose rates must be identified in time and 

space that correspond to a worker’s employment period, work locations, and job assignment; 

similarly, in order to maximize internal exposures, highest air concentrations and surface 

contaminations must be identified. 

Category 3: The most complex and challenging dose reconstructions consist of claims where 

the case cannot be dealt with under one of the two categories above. For instance, when a 

minimum dose estimate does not result in compensation, a next step is required to make a more 

complete estimate. Or when a worst-case dose estimate that has assumptions that may be 

physically implausible results in a POC greater than 50%, a more refined analysis is required. A 

more refined estimate may be required either to deny or to compensate. In such dose 

reconstructions, which may be represented as “reasonable,” NIOSH has committed to resolve 

uncertainties in favor of the claimant. According to 42 CFR Part 82, NIOSH interprets 

“reasonable estimates” of radiation dose to mean: 

. . . estimates calculated using a substantial basis of fact and the application of 

science-based, logical assumptions to supplement or interpret the factual basis. 

Claimants will in no case be harmed by any level of uncertainty involved in 

their claims, since assumptions applied by NIOSH will consistently give the 

benefit of the doubt to claimants. [Emphasis added.] 

In order to achieve the five objectives described above, SC&A reviewed each of the six TBDs, 

their supplemental attachments, and TIBs, giving due consideration to the three categories of 

dose reconstructions that the site profile is intended to support. The six LANL TBDs provide 

well-organized and user-friendly information for the dose reconstructor when adequate data were 

available to do that comprehensively. 

ORAUT-TKBS-0010-1, Rev. 00, Technical Basis Document for Los Alamos National 

Laboratory – Introduction (Buddenbaum 2005), explains the purpose and the scope of the site 
 

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profile. SC&A was attentive to this section, because it explains the role of each TBD in support 

of the dose reconstruction process. During the course of its review, SC&A was cognizant of the 

fact that the site profile is not required by the EEOICPA or by 42 CFR Part 82, which 

implements the statute. Site profiles were developed by NIOSH as a resource to the dose 

reconstructors for identifying site-specific practices, parameter values, and factors that are 

relevant to dose reconstruction. Based on information provided by NIOSH personnel, SC&A 

understands that site profiles are living documents, which are revised, refined, and supplemented 

with TIBs as required to help dose reconstructors. Site profiles are not intended to be 

prescriptive nor necessarily complete in terms of addressing every possible issue that may be 

relevant to a given dose reconstruction. Hence, the introduction helps in framing the scope of the 

site profile. As will be discussed later in this report, NIOSH may want to include additional 

qualifying information in the introduction to this and other site profiles describing the dose 

reconstruction issues that are not explicitly addressed by a given site profile. 

ORAUT-TKBS-0010-2, Rev. 00, Technical Basis Document for Los Alamos National 

Laboratory – Site Description, (Buddenbaum 2004), is an extremely important document, 

because it provides a description of the facilities, processes, and historical information that serve 

as the underpinning for subsequent LANL TBDs. 

ORAUT-TKBS-0010-3, Rev. 00, Technical Basis Document for Los Alamos National 

Laboratory – Occupational Medical Dose, (Johnson 2004), provides an overview of the 

sources, types of exposure, and the frequency of exams that workers potentially received. 

ORAUT-TKBS-0010-4, Rev. 00, Technical Basis Document for Los Alamos National 

Laboratory – Occupational Environmental Dose, (Cehn and McDowell-Boyer 2004), provides 

background information and guidance to dose reconstructors for reconstructing the doses to 

unmonitored workers outside of the facilities at the site who may have been exposed to routine 

and episodic airborne emissions from these facilities. 

ORAUT-TKBS-0010-5, Rev. 00, Technical Basis Document for Los Alamos National 

Laboratory – Occupational Internal Dose, (Argall 2004), presents background information and 

guidance to dose reconstructors for deriving occupational internal doses to workers. 

ORAUT-TKBS-0010-6, Rev. 00, Technical Basis Document for Los Alamos National 

Laboratory – Occupational External Dose, (Widner 2005), presents background information and 

guidance to dose reconstructors for deriving occupational external doses to workers. 

In accordance with SC&A’s site profile review procedures, SC&A performed an initial review of 

the six TBDs, their supporting documentation, and the three TIBs. Interviews with Site Experts 

are provided in Attachment 2. SC&A then submitted questions to NIOSH with regard to 

assumptions and methodologies used in the site profile. Prior to the conference calls with SC&A 

for the LANL Occupational External Dose TBD (Widner 2005), Introduction TBD 

(Buddenbaum 2005), Site Description TBD (Buddenbaum 2004), and Occupational Medical 

Dose TBD (Johnson 2004), NIOSH provided written responses to SC&A questions. The SC&A 

questions, along with the NIOSH responses, are provided in Attachment 3. 
 

 

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A series of conference calls were then conducted with NIOSH and ORAU, and the SC&A team 

to allow NIOSH to provide clarifications and to explain the approaches employed in the site 

profile TBDs. A summary of the series of individual conference calls with NIOSH, ORAU, and 

SC&A is provided in Attachment 4. NIOSH responded to action items identified in the 

conference calls and these supplemental NIOSH responses are provided in Attachment 5. 

Attachment 6 provides a listing of LANL-sponsored atmospheric and underwater tests. 

An extensive comparison was done between the methodologies used in the LANL TBD 

and other TBDs reviewed to date to determine environmental, internal, and external 

doses. This comparison focused on the methodologies and assumptions associated with 

dose reconstruction and resultant values used to obtain a POC. A detailed analysis is 

provided in Attachment 7. 

Individuals interviewed provided several comments that relate to the LANL Site Profile 

documents. These comments are provided and addressed in Attachment 8 and are 

separate from the site expert interview summaries found in Attachment 2. The 

information provided in Attachment 8 is from interviews and hardcopy documentation 

from Dr. Ken Silver (Silver 2005) of Eastern Tennessee State University and current 

employees at LANL. 

Information provided in the conference call with NIOSH was evaluated against the preliminary 

findings to finalize the vertical issues1

 addressed in the audit report. There are three levels of 

review for this report. First, SC&A team members review the report internally. Second, SC&A 

engages an outside consultant who has not participated in the preparation of this document to 

review all aspects of this report. The third level, referred to as the expanded review cycle, will 

consist of a review of this draft by the Advisory Board and NIOSH. The first two of these have 

been completed. 

After the Advisory Board and NIOSH have an opportunity to review this draft, SC&A plans to 

request a meeting with Advisory Board members and NIOSH representatives to discuss the 

report. Following this meeting, we will revise this report and deliver the final version to the 

Advisory Board and to NIOSH. We anticipate that, in accord with the procedures followed 

during previous site profile reviews, the report will then be published on the NIOSH Web site 

and discussed at the next Advisory Board meeting. This last step in the review cycle completes 

SC&A’s role in the review process, unless the Advisory Board requests SC&A to participate in 

additional discussions regarding the closeout of issues, or if NIOSH issues revisions to the TBDs 

or additional TIBs, and the Advisory Board requests SC&A to review these documents. 

Finally, it is important to note that SC&A’s review of the six TBDs and their supporting TIBs is 

not exhaustive. These are large, complex documents and SC&A used its judgment in selecting 

those issues that we believe are important with respect to dose reconstruction. 

1

 The term “vertical issues” refers to specific issues identified during our review, which were identified as 

requiring more in-depth analysis due to their potential to have a significant impact on dose reconstruction. 
 

 

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4.0 SITE PROFILE STRENGTHS 

In developing a TBD, the assumptions used must be fair, consistent, and scientifically robust, 

and uncertainties and inadequacies in source data must be explicitly addressed. The 

development of the TBD must also consider efficiency in the process of analyzing individual 

exposure histories so claims can be processed in a timely manner. With this perspective in mind, 

we identified a number of strengths in the LANL site TBDs. These strengths are described in the 

following sections. 

4.1 COMPLETENESS OF DATA 

In developing the Site Description TBD, ORAUT-TKBS-0010-2 (Buddenbaum 2004), NIOSH 

made extensive use of the LAHDRA report. Although this mainly focused on off-site 

environmental emissions, LAHDRA is the most comprehensive effort to retrieve documentation 

pertinent to radiation exposures at LANL. This has greatly enhanced the accuracy and 

completeness of the data provided in the Description TBD, ORAUT-TKBS-0010-2 

(Buddenbaum 2004), as well as in the Occupational Environmental Dose TBD, ORAUT-TKBS0010-4 (Cehn and McDowell-Boyer 2004). 

NIOSH has agreed to search and add additional available references to help substantiate 

information depicted in Tables 3.2 and 3.3 of the Occupational Medical Dose TBD ORAUTTKBS-0010-3 TBD (Johnson 2004). 

The NIOSH/ORAU team is aware of gaps in the TBDs, and has plans to update some of them 

based on new information gathered since the site profile's issuance. The NIOSH/ORAU team 

has gained access to nine additional boxes of documents that previously had been held for 

classification screening. They intend to review these documents for relevance to each element of 

the site profile. There will be substantial updates to the Internal Dose TBD (Argall 2004) and the 

External TBD (Widner 2005). 

The NIOSH/ORAU team is aware of gaps in the TBDs and has plans to update some of the 

documents. Most notably, there will be updates to the Occupational Internal Dose TBD (Argall 

2004), the Occupational External Dose TBD (Widner 2005), and the Site Description TBD 

(Buddenbaum 2004). Proposed changes for the Internal Dose TBD include: 

• 	 Addition of a discussion on the format and contents of the LANL Bioassay Database. 

This will address interpretation of data in the new LANL Bioassay Database for U-238 

and U-235, when both results are listed for a sample. 

• 	 Addition of descriptions of Delayed Neutron Activation Analysis (DNAA) and associated 

practices used by LANL for estimating uranium in bioassay samples. 

• 	 Clarification on minimum detectable activity (MDA) values used for the early years 

based on additional information obtained. 

• 	 Hypothetical estimates of missed intakes will be derived for workers with presumptive 

cancers potentially exposed during the RaLa project years. 
 

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• 	 Clarification of the bioassay protocol for Zia workers, including a discussion of 

procedures used for restricting Zia workers’ access to material handling areas. 

• 	 Clarification on the availability of bioassay data for radionuclides not currently in the 

LANL Bioassay Database. 

• 	 Development of internal co-worker doses to mitigate gaps in the data. 

• 	 Addition of a list of organs and the fission products that produce the highest potential 

dose to those organs. This is useful in assigning potential missed dose when whole-body 

count results are below MDA levels. 

• 	 Update information within the TBD, such as additional incidents based on documentation 

collected since the issuance of the TBD. 

Proposed changes for the External Dose TBD (Widner 2005) include: 

• 	 Update the photon energy group percentages for Accelerator Operations. 

• 	 Clarification regarding the adjustment factors to be applied to reported photon doses and 

the time periods and conditions under which they should be applied. 

• 	 Change the recommended distributions for n-p ratio from uniform distributions to 

distributions characterized by median and 95th percentile values. 

• 	 Addition of a distribution for plutonium facilities that handled Pu-238. 

• 	 Pending further clarification concerning what information is desired, will add a 

discussion of external dose monitoring practices applied to workers involved in critical 

assembly experimentation and/or criticality incidents, and/or information regarding 

radiation fields that would have been expected from those activities. 

• 	 Update information currently within the TBD based on documentation collected since the 

issuance of the TBD, and eliminate discrepancies that exist within the document. 

• 	 Determine applicability of recent Savannah River Site (SRS) TBD revision to the LANL 

TBD. 

In some cases, the changes have been communicated to the dose reconstructors, and are currently 

being implemented. SC&A is aware of the proposed changes; however, details of these changes 

were not available for this review. 

4.2 ADEQUACY OF DATA 

A good breakdown of the various site locations and activities as a function of time was provided. 

Dosimetry methods used for beta, photon, and neutron dose monitoring were described 

separately, and also as a function of time and technology changes. Some prescribed health 

physics monitoring procedures and record keeping methods were described, along with the 

logbooks containing this information. LANL has been fortunate to have noted scientists and 
 

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R&D facilities to address radiation and health physics problems throughout its years of 

operations. 

4.3 TECHNICAL ACCURACY/CLAIMANT FAVORABILITY 

The Occupational External Dose TBD, ORAUT-TKBS-0010-6 (Widner 2005) and the related 

Site Description TBD, ORAUT-TKBS-0010-2 (Buddenbaum 2004) were evaluated for relevance 

to external dose reconstruction (DR) for LANL workers, and to determine if the procedures 

recommended were technically sound and claimant favorable. 

(1) SC&A’s review of the Occupational External Dose TBD, ORAUT-TKBS-0010-6 

(Widner 2005) found that these documents provided a very extensive overview, and 

numerous details, concerning various site descriptions, lab operations, radiation 

monitoring, dose analysis, and dose records for LANL workers. 

(2) The Occupational Environmental Dose TBD applies a screening method to determine 

significance of radionuclides handled at LANL to environmental exposure. It is 

appropriate to eliminate radionuclides that contribute less than 1 mrem to the 

environmental dose over a select period of time. SC&A cautions NIOSH/ORAU to 

consider all radionuclides relative to the exposure from environmental media during 

their screening method. 

4.4 CONSISTENCY AMONG SITE PROFILES 

The implementation of ORAUT-OTIB-0006, Dose Reconstruction for Occupationally Related 

Diagnostic X-Ray Procedures, Revision 2 (Kathren 2003), has provided a great deal of 

consistency between different site profile assumptions. Incorporation of Revision 3 PC-1 

(Kathren and Shockley 2005) of this document would provide further consistency among site 

profiles. The NIOSH/ORAU team is moving in the right direction to obtain consistency in most 

assumptions for occupational medical exposure. 

4.5 REGULATORY COMPLIANCE 

The TBD’s use of personnel monitoring data and environmental monitoring data to determine 

dose is consistent with the requirements outlined in 42 CFR Part 82, as follows: 

• 	 Where in-vivo and in-vitro analyses are available, this information is provided for use in 

determination of internal dose. 

• 	 Where routine beta/gamma and neutron dosimeters are available and adequate, this 

information is provided for use in determination of external exposure. 

• 	 Where environmental measurements are available, these data are used as the basis for 

environmental dose. 
 

 

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5.0 VERTICAL ISSUES 

SC&A has developed a list of key issues regarding the LANL Site Profile. These issues relate to 

each of the five objectives defined in SC&A’s review procedures (SC&A 2004). Some issues 

are related to a particular objective, while others cover several objectives. Many of the issues 

raised below are applicable to other DOE and Atomic Weapons Employer (AWE) sites and 

should be considered in the preparation and revision of other site profiles. 

5.1 ISSUE 1: SITE PROFILE DOES NOT ADEQUATELY ADDRESS DATA 

INSUFFICIENCY FOR IMPACT AND IMPLICATIONS TO EARLY WORKER 

DOSE RECONSTRUCTION 

Information available for dose reconstruction in the early years is limited, inadequate or in some 

cases not available. Some gamma doses are available starting in the 1940s, but external radiation 

personnel monitoring did not include adequate methods to monitor beta, gamma, and neutrons 

until around 1951. Lack of complete photon dosimetry data in the early days brings into 

question the ability to compute neutron dose by using the n-p method. Early internal monitoring 

techniques were limited to urinalysis for plutonium and polonium, and nasal smears. Work with 

radionuclides, such as tritium, uranium, fission products, BaLa, radium, and other alpha and beta 

emitters, was diverse, extensive, and preceded many of the bioassay techniques for these sources 

developed in the late 1940s and 1950s. Overall, the goal in the early years was to keep 

individuals within laboratory defined tolerances; however, it was not uncommon to exceed the 

tolerances of the time for mission purposes. 

In view of this early history, SC&A finds it problematic that the TBD methodology treats the 

historic dose record as if it is sufficiently complete for LANL workers of that period, particularly 

for 1943–1950. Each worker’s actual dose will depend on the individual’s radiological exposure 

circumstances in terms of type of work, work location, and time period, and cannot necessarily 

be extrapolated from co-workers or later dose data, or solely from MDL values. A lack of dose 

records in the early days does not warrant an assumption that workers did not receive any dose 

above the MDL during missed monitoring periods or that assigning the median dose is 

necessarily claimant favorable. This approach to dose reconstruction could lead to an 

underestimation of doses for workers who were not badged, or whose results were not recorded. 

For example, the Occupational External Dose TBD, ORAUT-TKBS-0010-6 (Widner 2005, 

pg. 65), recommends assigning a median dose of 199 mrem/year for 1948 for an unbadged 

worker, and (Widner 2005, pg. 68) recommends assigning a missed dose of 240 mrem/year for 

1948. This latter dose assignment would equate to only approximately 1 mrem/day 

(0.12 mrem/hr) for a worker who likely worked in close proximity to radiological facilities, was 

presumably exposed to some contamination, and was operating in an environment where he and 

his co-workers were learning and applying evolving radiation control measures. This was at a 

time when the radiation protection standards and guidelines were much less stringent than they 

are today. Given that the driving concern at the time was to keep the exposures below the 

guideline limits (i.e., 10% of 15 rem/year), radiation controls would have been considered 

satisfactory if exposure was maintained at or below these levels. However, the TBD approach 
 

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would be non-conservative if one assumes that 10% of 15 rem/year equates to around 

6 mrem/day, which is much greater than the proposed 1 mrem/day median dose that would be 

applied. 

5.1.1 Background 

While the site profile TBDs catalogue the radionuclides in use and outline the history of 

operations, they do not adequately characterize this history in terms of the often primitive 

radiological conditions under which work was performed and the inconsistent manner in which 

personnel monitoring was conducted and records maintained. 

During the Manhattan Engineering District (MED) era at Los Alamos, much of the work was 

experimental in nature resulting in trial and error. Early experimental physics and weapons 

research resulted in immediate work with radiation producing devices, such as the cyclotron, 

electrostatic generators, neutron sources (e.g., RaBe, PoBe, etc.) Early activities included fast 

neutron research, slow neutron research, instrument development and testing (including 

radiological instrumentation), accelerator operations, and weapons component development and 

testing. During the early development period, experimentation with radiation generating sources 

led to work with Ra-Y-Be, yttrium, tantalum, Ra-D2O, and YBe, and mesothorium (Ra-228) 

sources. Fission measurements were made on thorium, ionium, protractinium, U-234, U-235, 

and Pu-239 (LAP 1944a, LAP, 1944b). Early work also included development of tampers, 

initiators, weapons housing, high explosives, and detonators. Los Alamos continued weapons 

development after World War II, and was the lead site for U.S. nuclear weapon component 

fabrication until 1949, when Hanford began making pits. 

“Monitoring was scarce and rather primitive,” observed the first director of LANL’s Health 

Division, Dr. Robert Stone. “The whole clinical study of the personnel is one vast 

experiment” (Stone 1948). Stone’s efforts to create an expanded safety margin through 

increased worker monitoring to reduce exposures below the 1934 limits then in place were met 

with opposition by his superiors. 

Ted Lombard was an enlisted man in the U.S. Army assigned to work at the Los Alamos 

Laboratory during the war who recalled the less-than-ideal working conditions: 

I’ll tell you what the working conditions were at Los Alamos... We used to go to 

Fort Douglas, Utah in ambulances, pick up uranium and plutonium. We carried 

dosimeter badges in our pockets because you couldn’t display them...Then [after 

the badges were turned over to an officer] we would proceed to unload uranium 

and plutonium barehanded...the fumes and dust were constantly in the air; there 

was no ventilation system. The dust was on the floor. Uranium chips would be in 

your shoes that you continued to wear. You went to eat with the same clothes on, 

you went to the barracks with the same clothes and sat on the beds... 

contamination was rampant and there was little or no protection, particularly for 

G.I.’s. (NCRV 1980) 
 

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While these primitive radiological control circumstances are acknowledged in the site profile, a 

coherent dose reconstruction approach is not presented. 

5.1.2 External Monitoring of Early Workers 

The Occupational External Dose TBD, ORAUT-TKBS-0010-6 (Widner 2005, pg. 9), states the 

following: 

LANL has used facility and individual worker monitoring methods to measure and 

control radiation exposures. Records of radiation doses to individual workers 

from personnel dosimeters worn by the worker and coworkers are available for 

LANL operations beginning in 1943. Doses from these dosimeters were recorded 

at the time of measurement and routinely reviewed by operations and radiation 

safety staff for compliance with radiation control limits. 

According to the Occupational External Dose TBD (Widner 2005), external radiation personnel 

monitoring did not include adequate methods to monitor beta, gamma, and neutrons until around 

1951 (i.e., see Table 6-5 on pg. 21 and Table 6-7 on pg. 28). Some gamma doses were measured 

in the early days, but beta, gamma, and especially neutron doses were not adequately or routinely 

monitored. This includes n-p ratio values needed today for neutron dose reconstruction. Lack of 

complete dose data that may affect dose reconstruction is evident from other sections of the TBD 

(Widner 2005) and historic documents, as cited below: 

• 	 Relatively high unmonitored exposures were received by workers in early experiments at 

LANL’s Omega Site as documented by Dan Mayers (Mayers 1946) in which he noted 

that: 

No accurate data on the amounts [of radiation exposure] is available 

although measurements were made but not recorded at the time. Mr. Feld 

estimated total personnel exposure to be roughly as follows for all three 

experiments: ...” 

The article goes on to state that for the three experiments, the estimated total gamma plus 

neutron dose (in terms of Equivalent Gamma Dose using a conversion factor of 

1 neutron r = 5 gamma r) was 3–15 r for worker #1, 2–10 r each for worker #2 and #3, 

and 1–5 r each for worker #4 and #5. 

• 	 According to several documents, the exposures that were measured for these three 

workers did not necessarily make it into the worker’s records. (LANL 1956a and 

Hempelmann 1946) 

• 	 The Occupational External Dose TBD states in Section 6.2.1.5, page 19, that dosimetry 

measurements made prior to August 1950 apparently did not make it into long-term 

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• 	 Page 6 of the Introduction TBD, ORAUT-TKBS-0010-1 (Buddenbaum 2005), states 

“Many of the exposure histories and work records are not specific about the assigned 

work areas of individuals.” 

• 	 According to recent worker interviews, the Radiation Control Technicians (RCTs) wore 

film badges during some jobs; however, the RCT was the least likely exposed individual 

in the group, because they were not involved in the hands-on tasks. Therefore, 

assignment of average co-worker doses to these workers on this basis would result in 

underestimated dose, because they would not be based on the most highly exposed 

workers. 

These concerns with photon dosimetry are especially important because of NIOSH’s intent to 

use n-p ratio values to calculate neutron doses.2 An error in photon dosimetry is doubled when 

used as a basis for neutron dosimetry. Additionally, under such circumstances, the neutron dose 

cannot be used to check the gamma dose, nor can the gamma dose be used to check the neutron 

dose results. 

5.1.3 Internal Monitoring of Early Workers 

LANL was among the first facilities to handle major quantities of elements, such as plutonium 

and fission products. As such, the development of personnel monitoring, e.g., in-vivo and invitro, was in its infancy and was evolving as experience was gained at the laboratory. In 

retrospect, we know that standards were not as tight as they should have been and sensitivity of 

the bioassay and in-vivo measuring systems were not adequate to detect uptakes at levels 

considered to be safe by today’s standards. These points are acknowledged in the Occupational 

Internal Dose TBD (ORAUT-TKBS-0010-5, Argall 2004); however, it is of concern to SC&A 

that significant and chronic exposures to these internal emitters may have occurred as a result of 

monitored personnel being exposed at levels below the sensitivity of the methods used for 

exposure detection or where unmonitored personnel were exposed. 

The TBD, Section 5.1, page 9, points out that: 

...the only method of monitoring intake was through loose contamination swipes... 

Nasal swipes, also called ‘nose counts,’ were used to indicate potential intakes. 

Section 5.2.1, page 21, of the TBD, notes that: 

After the development of urine bioassay techniques, nasal swipes were used to 

indicate the need for follow-up bioassay, although bioassay was not always 

performed immediately following a positive nasal swipe. (McInroy et al. 1991) 

The use of nasal swipes can only be used as one of several available exposure indicators; 

however, the lack of a positive nasal swipe does not preclude the possibility that a very 

2

 NIOSH and SC&A conference call, March 21, 2006. 
 

 

 

 

 

 

 

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significant uptake may have occurred. Extensive experience in the nuclear industry has shown 

that significant uptakes have occurred where nasal swipes did not exceed the 50 cpm action 

level. SC&A is concerned about the heavy dependency on nasal swipes, even into the 1980s, 

and the number of workers that may have had positive uptakes that may have been missed given 

the heavy reliance on nasal swipes. 

The TBD notes in several places that only workers with a significant potential for exposure were 

monitored. Guidance in the Chemistry and Metallurgy Health Handbook of Radioactive 

Materials (Aebernald et al. 1945) states that only those people who worked directly with 

plutonium and polonium, or those in an accident involving these radionuclides, were monitored 

by urinalysis. In the case of uranium, only those individuals working with tuballoy or U-235 

who showed albuminuria during routine weekly medical urinalysis testing were required to 

submit a urine sample to be tested for tuballoy (Aebernald et al. 1945). Thus, other workers with 

a potential for exposure and uptake, but not so identified, would not have been monitored. The 

TBD further notes that “many of the exposure histories and work records are not specific about 

the assigned work areas of individuals...” (Argall 2004, Section 5.1, pg. 11); this raises further 

doubts regarding the basis for applying co-worker internal dose distributions to unmonitored 

individuals. 

The early LANL bioassay programs, up to the 1960s, missed many radionuclides before the 

health physics significance of them became obvious and bioassay measurement techniques were 

developed. Table 1 lists a portion of these radionuclides, the initial year of potential exposure, 

and the year when approved bioassay monitoring techniques first became available for these 

radionuclides. [This information was compiled from H-Division progress reports and other early 

H-Division technical documents. The first year of exposure reflects the year the radionuclide 

was first cited in these reports as being present in operations and monitored.] 

Table 1: Radionuclides Handled in the Early Years of Operations at LANL 

Radionuclide First Year of Potential 

Exposure Bioassay Start Year 

Plutonium 1943? 1944 

Uranium 1943 1949 

Tritium 1945 1950 

Americium 1947? 1954 

Polonium 1944 1944 

Fission Products 1944 1950 

Strontium 1944 1952 

Ra-226 + daughters 1944 1958 

Iodine 1945? 1952 

Thorium ? 1956? 

Curium ? ? 

Ba-La 1944 ? 

Other alpha emitters 1944? ? 

Other beta emitters 1944 ? 
 

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In summary, SC&A finds from the TBD, H Division progress reports, and other documentation 

from LANL’s early operations that: 

(1) Only workers with a significant potential for exposure were monitored and work 

histories are not specific about assigned work areas. 

(2) Some individuals worked in laboratory areas with a potential for exposure and were 

never monitored nor were their job tasks recorded as having radiation exposure 

potential. 

(3) Major emphasis was placed on monitoring surface contamination levels and using 

positive nasal swipes as primary indicators or “triggers” to initiate bioassay sampling for 

potential uptakes. 

(4) Average chemical recoveries and matrix blanks were not reported prior to 1957, 

according to the TBD (Argall 2004, Section 5.2.1, pg.18). 

Based on the foregoing, SC&A believes that the site profile does not provide an adequate and 

complete basis for dose reconstruction for unmonitored and even some monitored workers in the 

1940s through possibly as late as the 1960s. The dose data is apparently unavailable for many 

radionuclides, the work location is not recorded, and the requisite measurement sensitivity for 

chronic or even, in some cases, acute exposures is not evident. Section 5.2.1 of the TBD does 

present a section on “Missed Intakes;” however, it does not adequately describe the approach 

that NIOSH will use to reconstruct a claimant-favorable dose for those that may have been 

missed entirely. In subsequent discussions with NIOSH, it was learned that they intend to apply 

a dose of 1/3 of the UPPU average dose for workers of early years. The NIOSH assignment of 

1/3 of the UPPU average dose for workers of this period does not appear to be sufficiently 

claimant favorable in light of the fact that the sensitivity for uptakes exceeded a maximum 

permissible body burden (MPBB), and lung counting techniques and equipment were not yet 

developed. 

Two papers—The Los Alamos Scientific Laboratory’s Experience with Plutonium in Man 

(Langham et al. 1962) and Studies on Persons Exposed to Plutonium (Voelz et al. 1978)— 

provide insight and substantiation of this issue, describing the difficulties of detection and 

monitoring confronted in those early years at Los Alamos. 

5.2 ISSUE 2: INADEQUATE CONSIDERATION HAS BEEN GIVEN TO 

POTENTIAL EXPOSURE AND MISSED DOSE FROM OTHER 

RADIONUCLIDES 

Numerous radionuclides were handled at LANL ranging in quantities from fractions of a gram to 

kilograms. The amounts of particular radionuclides handled changed over time as LANL shifted 

from research and development (R&D) to production. Radionuclides other than plutonium, 

uranium, tritium, and polonium, handled at LANL included radium, thorium, actinium, 

protactinium, americium, neptunium, curium, lanthanum, barium, yttrium, and other fission 

products, alpha emitters, and beta emitters associated with accelerator production and weapons 

development. Inadequate or no consideration in the Occupational Internal Dose TBD, ORAUT­
 

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TKBS-0010-5 (Argall 2004), has been given to the potential exposure and missed dose from 

radionuclides other than the aforementioned plutonium, tritium, polonium, and uranium. Some 

of these radionuclides are listed in Table 5A-10 as a nuclide handled in particular technical areas. 

In several instances, the TBD directs the dose reconstructor to rely on the claimant interviews for 

identification of potential exposure to non-traditional radionuclides. Inadequate dosimetry 

characterization and guidance is given for assignment of dose from Sr-90, Cs-137, Ba/La-140, 

P-32, C-14, Pa-231, radioiodine, tritides, and thorium. No clear basis is provided for dose 

assignment for radium, actinium, neptunium, curium, yttrium, tantalum, radon, and radionuclides 

created as a part of the medical isotope program. Adequate guidance is not provided for 

potential exposures from special tritium compounds, including organically bound tritium (OBTs) 

and special metal tritides (SMT) (see Issue 3, Section 5.3). In addition, as indicated in 

Attachment 4, LANL Occupational Internal Dose TBD Conference Call Summary, the 

NIOSH/ORAU team has decided not to pursue bioassay data for many radionuclides not 

currently in the LANL Bioassay Repository. 

5.2.1 Missed Dose from Other Radionuclides 

Both R&D and production operations have contributed to the extensive and diverse list of 

radionuclides historically present at LANL. The D-Building and Chemical Metallurgy Research 

(CMR) facility were both heavily involved in R&D to support the weapons program. 

Accelerator facilities have been used to produce both stable and radioactive elements for use by 

the DOE complex, and commercial vendors. Reactors have been used to irradiate elements. The 

Health Research Laboratory (HRL) has conducted studies on the metabolism of radionuclides in 

animals and humans. Tritium facilities have active in maintaining the U.S. nuclear warhead 

stockpile. The long-term operations and R&D activities at LANL provided constant 

opportunities for workers to come in contact with radionuclides spanning the periodic table. 

Some of the operations handling other than these “secondary” radionuclides are listed below. 

• 	 Biological research with P-32, Na-24, and C-14 labeled material 

• 	 Use of the Th-229 (d, pf) reaction to study the fission of Th-230 

• 	 Medical Radioisotope Research processing and shipping, including 13 different 

radionuclides 

• 	 Production of large quantities of N-15 and O-18 for scientific research 

• 	 Use of iodine in weapons diagnostics 

• 	 Determination of fission product yields of Np-237 relative to U-235 

• 	 Reduction of NpF4 to Np metal (Morgan et al. 1962) 

• 	 Processing of U-233 solution into metal 

• 	 Purification of americium from rare earths (Coleman 1956) 

The Los Alamos Neutron Science Center (LANSCE) produces substantial quantities of a number 

of radioisotopes, including both short-lived and long-lived radionuclides (Peterson 2002). 
 

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Handling of radioactive waste itself involves potential exposures to over 50 different 

radionuclides. The primary mission of the CMR facility (TA-3 (South Mesa Site), Building 29) 

has been to provide a facility that supports engineering, chemistry, and research operations for 

groups working to ensure the safety and reliability of the U.S. nuclear warhead stockpile, 

improve the capability to handle nuclear materials and manufacture nuclear components, provide 

support to plutonium recovery and processing operations, and solve problems related to energy 

and the environment. As a result, CMR has worked with uranium, plutonium (Pu-238, Pu-239, 

Pu-242), americium (Am-241, Am-243), curium (Cm-244, Cm-248), neptunium (Np-237), Cf249, and fission products either in a pure form or as a contaminant (Steele and O’Neil 1998). 

Finally, radionuclides such as fission products have been produced as a byproduct of operations. 

These potential sources of exposure from secondary and so-called “exotic” radionuclides are 

based on a limited SC&A review of LANL operational history and available health physics files. 

Further research by NIOSH into these non-traditional radionuclides should be completed in any 

revision of the LANL site profile to assure their significance and dose contribution are fully 

addressed. Bioassay techniques should be evaluated for entire periods of potential exposure for 

the effectiveness in detecting other radionuclides. Appropriate methods for internal monitoring 

were not always available for all years of potential exposure. Although the TBD (Argall 2004) 

acknowledges the existence of non-traditional radionuclides, adequate direction is not provided 

on how and when to assess potential missed dose for many of them. The site profile is reliant on 

claimant interviews to ascertain potential exposure to any such nontraditional radioactive source, 

an approach that put former workers, and particularly their survivors, at a disadvantage because 

of the lack of hazard identification, lack of records, and considerable secrecy at the time. The 

TBD (Argall 2004) has also not considered the possibility that due to secrecy, the energy 

employee may not have known what radionuclides were in the workplace. NIOSH/ORAU 

should base missed dose assignments on available data, technical reports, and other sources of 

information to ascertain potential exposure to non-traditional radionuclides. 

5.2.2 Radionuclides with Limited Bioassay Data 

The Occupational Internal Dose TBD, ORAUT-TKBS-0010-5 (Argall 2004) points out in 

Section 5.2.7 (pg. 32) that: 

LANL has always been a center for research. As such, small-scale use of various 

radionuclides not addressed above has occurred throughout the history of LANL. 

Little or no documentation has been found on bioassay for these nuclides. 

Furthermore, it is stated in the Occupational Internal Dose TBD, ORAUT-TKBS-0010-5 (Argall 

2004), Section 5.2.5 (pg. 31), that: 

Records of 90Sr urinalysis, routine or special, are very sparse. The historical 

compilations of procedures do not list a specific 90Sr urinalysis procedure. It 

appears that any record of 90Sr analysis actually indicates that LANL performed a 

gross beta analysis or sent a sample to an outside laboratory. Strontium-90 dose 

currently can be reconstructed only when 90Sr results are actually listed for an 
 

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individual... No information is available on MDA for 90Sr analysis. [Emphasis 

added.] 

A review of monthly and annual H-Division progress reports clearly indicate that bioassay 

samples were collected and analyzed for Po-210, gross beta, Pm-147, radioiodine, Sr-90, Zn-65, 

Pb-210, curium, gross gamma, fission products, Th-230, Th-232, Ra-226, Ra-228 

(mesothorium), radiolanthanum, and actinium. There is also indication of radon breath analysis 

(Schulte 1966). In addition, air sampling data is available for Ta-182, which appears to have 

been in use since the 1940s. 

TBD guidance provided on the assignment of dose from polonium and other radionuclides, 

merely guides the dose reconstructor to assign a dose if there was a potential for exposure to the 

radionuclide, or when exposure is indicated in a claimant interview: 

Therefore, missed dose for polonium should be assessed only if actual polonium 

bioassay has been performed for the individual or if there is indication, through 

claimant interview, that the employee was actually exposed to the polonium. 

(Argall 2004, pg. 31) 

And, 

These nuclides [referring to 227Ac, 32P, 14C, thorium and 231Pa] should only be 

assessed when there is an indication that the worker had potential for interaction 

with that nuclide. (Argall 2004, pg. 32) 

Given the secrecy under which employees worked, they cannot be expected to know all of the 

radionuclides they were exposed to, especially those not directly involved in operations. 

Furthermore, it is highly unlikely that a claimant survivor will be able to provide details on 

exposures to any radionuclides, let alone such extraneous sources. 

There is clear indication that bioassay data existed for radionuclides other than polonium, 

tritium, uranium, plutonium and americium, which are included in the LANL Bioassay 

Repository. In SC&A’s conference call with NIOSH/ORAU (Attachment 4), it was stated that 

the data for unusual radionuclides is not easily accessible, although there is some data available 

in logbooks. Inadequate guidance on “other” radionuclides is particularly troubling since the site 

has not provided the original bioassay data files for these radionuclides and NIOSH/ORAU 

apparently does not plan to pursue them (see Attachment 2). SC&A recommends that NIOSH 

retrieve these original bioassay data files for use in dose reconstructions, where applicable. If 

bioassay records cannot be retrieved, a methodology for assignment of dose should be 

developed. Further information on where the radionuclides were handled and what time periods 

this covers needs to be collected, reviewed, and included in the TBD in the context of dose 

reconstruction. 

In summary, SC&A recommends further evaluation of radionuclides handled at LANL to 

determine the extent of potential exposures and how it impacts dose reconstruction to the organs. 
 

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Attempts should be made to retrieve bioassay data where it is available, and include internal dose 

reconstruction methodologies for radionuclides without appropriate bioassay coverage. 

5.3 ISSUE 3: SPECIAL TRITIUM COMPOUNDS NOT ADEQUATELY 

ADDRESSED 

Adequate characterization and guidance for special tritium compounds is not provided in the 

Occupational Internal Dose TBD, ORAUT-TKBS-0010-5 (Argall 2004), including OBTs and 

SMTs. There is a complete reliance on OCAS-TIB-002, Tritium Calculations with IMBA 

(OCAS 2003), which only provides direction on how to enter urine measurements into the code. 

Although the dose consequences from special tritium compounds may not be significantly larger 

than those from tritiated water (HTO), NIOSH must be familiar with the special tritium 

compounds handled, the quantities of material, the locations and time periods of potential 

exposure, and the physical behaviors of tritium compounds in the environment (e.g., conversion 

to HTO, formation of rust) to correctly characterize tritium exposure. Bounding techniques, as 

proposed for SRS, cannot be effectively developed and applied without some basic 

understanding of the compounds handled and the extent to which individuals were exposed. 

In order to develop a bounding exposure, NIOSH must make themselves familiar with the 

special tritium compounds handled, the quantities of material, and the locations and time 

periods of potential exposure. Some thought should be given to the chemical behavior of 

tritium, especially as it related to the decontamination and decommissioning (D&D) of 

aging tritium facilities and other facilities where tritium was a byproduct of operations. 

LANL has been involved in work with tritium since the 1940s. Some of the major tritium 

facilities formerly or currently at LANL include: 

• High Pressure Tritium Laboratory (HPTL) 

• Tritium System Test Assembly (TSTA) Facility 

• Tritium Science and Fabrication Facility (TSFF) 

• Weapons Engineering Tritium Facility (WETF) 

The HPTL (also called the Gas Handling Facility) was originally tasked with conducting 

research and development on tritium handling technology. This facility took over production 

work for a period of time, processing tritium gas (HT) and repackaging HT into small-volume 

high-pressure vessels. In 1992, WETF began receiving tritium and tritium-contaminated gases, 

repackaging these gases, and preparing them for shipment to other sites. TSFF provided a 

facility for R&D involving work with HT and metal tritides (MT). TSTA was involved in the 

use of tritium for development and demonstration of fusion fuel cycle technology. Other areas 

onsite which involved potential exposure to tritium include: 

• Van de Graaff Accelerator (TA-3-16) 

• Plutonium Facility Site (TA-55) 

• F Area Vaults 
 

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• M Building 

• Y Building 

• HRL 

• Ion Beam Facility (IBF) 

The exact forms of tritium encountered in these facilities are not available; however, over the 

course of operations, LANL has handled tritium in the form of HTO, HT, organically bound 

tritium (OBT), and MT. A majority of the tritium handled was in the form of HTO or HT. HTO 

was also produced by exposure of HT and some special tritium compounds to air. Fires 

involving tritiated gas can also produce HTO. Tritium handling operations, research and 

development activities, and tritium facility D&D have exposed workers to other forms of tritium. 

The HRL and the IBF used labeled compounds, or OBTs, in the course of its research. 

Worker exposure to MT included hydrides and dihydrides of metals associated with accelerator 

targets and weapons components (Inkret et al. 1999). More specifically, LANL has handled a 

broad variety of light and heavy MT, including hafnium tritide and uranium tritide. Other forms 

of tritium compounds, such as tritiated pump oil, rust, pump oil droplets, tritiated methane, and 

tritiated solvents, were formed during operations with HTO and HT. 

The approach defined for tritium dose estimation provided in the TBD (Argall 2004, pp. 23–25) 

is not sufficient for many cases that involved significant exposures to stable tritiated compounds 

(STCs). The TBD refers the dose reconstructor to the guidance provided for exposure to tritiumlabeled compounds and tritium particulates outlined in OCAS-TIB-002, Tritium Calculations 

with IMBA (OCAS 2003). This TIB merely provides directions on the use of IMBA to calculate 

tritium doses. There is no discussion on how to differentiate between intakes of HTO, HT, 

OBTs, or tritium particulates. There is no guidance on how to interpret bioassay data, what 

particle size to assume for particulates, or what solubility class to use. 

The TBD recognizes the variability in distribution and absorption of OBT (Argall 2004, 

pg. 23): 

The first approximation of the dose from OBT (labeled) compounds is the tritium 

in body water dose. However, the absorption, distribution, and excretion of 

tritium-labeled compounds are specific to the chemical and physiological 

behavior of the compound. 

The TBD identifies OBTs as the predominant form of tritium at the HRL and IBF Buildings. 

With respect to MT, the TBD recognizes their existence at LANL and the differences in potential 

dose to the lungs; however, it again refers the dose reconstructor to OCAS-TIB-002 (OCAS 

2003). Information on when and where SMT exposures may have occurred is not provided 

(Argall 2004, pg. 24). 

Information on building locations and years of operation when MT might have 

been encountered is not currently available. The claimant telephone interview 

can provide indications that a person was exposed to MT. If the dose 
 

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reconstructor encounters a case involving exposure to MT, discussion among the 

task leadership might be needed to determine the appropriate biokinetic model. 

Although the TBD has considered tritium-labeled compounds as a potential source of OBTs, it 

has not considered OBTs formed when tritium reacts with organic materials. The main types of 

OBTs found are tritiated solvents, tritiated oil, and solid particulates (e.g., organic dust, plastics, 

etc.) The absorbed dose from tritium in organic components is dependent on the specific 

chemical compound in which the material is bound. OBTs in the form of solid particulates 

reside in the lungs for a longer period of time resulting in higher dose to the lungs. More 

information on how prevalent OBTs are in the LANL work environments should be gathered, 

and consideration given to the potential difference in resulting dose. 

Special metal tritides are solid substances containing tritium that do not readily react with air or 

in aqueous solutions, because tritium is tightly bound to the matrix. Because SMTs are relatively 

insoluble, and the retention of this type of tritium is longer than HTO in some organs, the 

internal dose delivered to the organ is higher. For particles of tritium, the lung is the primary 

organ of concern. Some of the tritium may leach out in the lung fluids and then be incorporated 

into the body water. These particles may also produce OBT from contact with lung tissue, which 

would further complicate the metabolic process (DOE 2004). 

McConville and Woods (1995) discuss the challenges with determining internal dose from MT: 

Tritium in the form of metal tritides particles presents a peculiar problem for the 

calculation of internal dose. Standard calculations indicate that just a few 3 to 

5 micron sized particles appears to lead to a very large dose. There are very few 

data on which calculations can be based. 

Inkret et al. (1999) found that hafnium tritide had a dissolution half-time of more than 105

 days. 

Cheng et al. (1997) determined the dissolution time for fine and coarse titanium tritide particles 

to be 33 days and 361 days, respectively. International Commission on Radiological Protection 

(ICRP) publications have not provided a dosimetric model for the calculation of internal dose 

from MT. 

Furthermore, STCs present unique challenges to radiological protection programs. Routine 

workplace monitoring techniques make it difficult to differentiate between STCs and more 

common forms of tritium, such as HTO. Due to the physical and chemical behavior of STCs, 

common bioassay and dose calculation models can be ineffective. For select STCs, air 

monitoring is preferable to bioassay (DOE 2004). The ICRP Database of Dose Coefficients: 

Workers and Members of the Public (ICRP 2001) provides information on tritium in particulate 

form (Types F, M, and S). In these cases, the default parameters of lung clearance and 

absorption are applied and the biokinetic model for HTO is used. Thus, the dose coefficients 

from the SMTs should be equal to the generic types F, M, and S, if the ICRP recommendations 

are followed. 
 

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Dose reconstructors should be made aware of the characteristics of STC excretion in urine to 

enable them to distinguish between STCs and tritium oxide or HT. For example, McConville 

and Woods (1995) demonstrated, with individual excretion data following tritide uptakes, that 

tritium excretion curves for particulate tritides do not follow a simple exponential curve, as is the 

case with HTO. In the case of these individuals, tritides built up for a few days followed by a 

more traditional elimination curve. 

SC&A agrees with preliminary NIOSH proposals for derivation of a bounding estimate based on 

maximum potential exposures that a worker may have received over the years from an assumed 

very insoluble tritide form. In order to develop a bounding exposure, NIOSH would need to 

make themselves familiar with the special tritium compounds handled, the quantities of material, 

and the locations and time periods of potential exposure. Some thought should be given to the 

chemical behavior of tritium, especially as it related to the D&D of aging tritium facilities and 

other facilities where tritium was a byproduct of operations. 

With the these concerns in mind, SC&A does not feel the Occupational Internal Dosimetry TBD, 

ORAUT-TKBS-0010-5 (Argall 2004) does an adequate job of addressing potential doses from 

uptakes of OBT and MT. Dose reconstruction guidelines need to be more specific and provide 

more backup materials to enable claimant-favorable estimates of high dose from STCs. 

5.4 ISSUE 4: DOSE ESTIMATION NOT ADDRESSED FOR LANL PERSONNEL 

ASSIGNED TO WEAPONS TESTING 

Exposure conditions and historic dosimetry practice related to LANL personnel participation in 

weapons and safety testing has not been considered in the site profile. LANL sponsored nuclear 

weapons testing of their weapons designs, supporting other laboratories conducting tests, and 

conducted safety experiments. Their involvement in weapons testing began at the Trinity site in 

Alamagordo, New Mexico on July 16, 1945, and continued until the end of testing in 1992. 

Included are LANL’s atmospheric and underwater tests at the NTS and PPG, all of which are 

listed in Attachment 6. 

The site description TBD, ORAUT-TKBS-0010-2, recognizes LANL’s participation in testing: 

They [Los Alamos scientists and engineers] were involved in many tests of 

nuclear devices in the continental United States, the Pacific, and Alaska, 

including some that were part of the Plowshare program for development of 

peaceful applications for nuclear explosives. (Buddenbaum 2004, pg. 11) 

Furthermore, the TBD recognizes LANL’s participation in the Rover Project: 

LANL was also responsible for the design and manufacture of test reactors for the 

Rover Project. Once the reactors were assembled and verified within 

specifications, they were shipped to the Nevada Test Site for testing. 

(Buddenbaum 2004) 
 

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Although LANL participation is mentioned in the site description, no characterization or 

evaluation of LANL worker dose from participation in weapons and safety testing has been 

included in the internal, external, and environment TBDs. While it is understood that NIOSH 

under EEOICPA protocols establishes work location, including work at other Atomic Energy 

Commission (AEC) or DOE sites, to enable dosimetry records to be obtained, it is not clear from 

either the LANL or NTS site profile how visiting LANL employees on testing missions were 

monitored and their doses recorded (i.e., who was monitored and how, how were the recorded 

doses integrated with their personnel dose record at LANL, and what status was accorded 

Reynolds Electrical Engineering Company (REECo) monitoring data?). 

For example, the NTS site profile has not been referenced for determination of missed dose at 

the test site, itself. No site profiles currently exist to provide guidance on how to assess potential 

missed dose at Trinity, Amchitka, or the PPG. This facet of exposure to LANL employees 

requires treatment in the site profile or a TIB. The exposure conditions during these activities 

will differ from those received at the LANL site itself, and should be specifically addressed. 

The test group from the laboratory responsible for the design of the weapon (e.g., LANL, 

Lawrence Livermore National Laboratory (LLNL), or Sandia National Laboratory (SNL)) sent a 

contingent of personnel to the test sites for testing preparation, detonations, recovery of data and 

materials post-detonation, and support functions (including radiological safety). 

The J-Division was responsible for managing the testing program, and the H-Division provided 

considerable safety and health support for weapons testing. 

Members of the staff of H-Division have held the full responsibility for 

radiological safety, first aid, and medical care, and safety for the test 

organization, with responsibility for radiation levels within a radius of 200 miles 

from the test site. (LASL 1951) 

Rotating crews of laboratory personnel were sent to the site for tests, with a typical test operation 

involving 50 or more personnel. These crews occupied the same areas as REECo employees, 

exposing them to the same hazards. Monthly H-Division Progress reports discuss the support 

provided at Operation Greenhouse, Operation Buster-Jangle, Operation Ranger, Operation 

Snapper, Operation Upshot-Knothole, and Operation Teapot by LANL radiation safety 

personnel. 

Responsibilities of NTS and LANL radiological control staff were delineated by NTS and LANL 

in procedures and the Test Manager’s Operational Plan. REECo served as a support contractor 

to the sponsoring laboratory providing dosimetry and records services, and instrumentation. 

These records are currently being retrieved by NIOSH from the Nevada repository, although it is 

uncertain how NIOSH determines for which individuals this data is to be requested. The 

responsibility for personnel monitoring for tests conducted in PPG appears to have been the 

responsibility of LANL, or the Nevada Operations Office (NOO). LANL personnel monitored 

individuals involved in the Trinity Test. Operations performed by LANL staff included test 

preparation, detonation, retrieval of equipment and material after detonation, follow-up 
 

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monitoring after detonation, monitoring during analysis of weapons debris, and decontamination 

of test sites as necessary. These assignments could last up to several weeks. Radiological 

personnel were frequently deployed to test areas to assist with radiological safety problems at 

test sites. 

In October, a monitor was sent to Eniwetok to take care of radiological safety 

problems in connection with current decontamination and construction work. 

(LASL 1949) 

Furthermore, 

The unsuccessful attempt to launch a high-altitude detonation from Johnston 

Island resulted in the spread of a considerable quantity of plutonium in the launch 

area. The subsequent decontamination of this area was carried out under the 

supervision of three representatives of the Health Physics Group of H-1. Prior to 

decontamination, most of the pad was contaminated in excess of 2,000,000 cpm 

alpha per 55 cm2

 probe area. (Shipman 1962) 

In the cases where LLNL or SNL sponsored the weapons test, a smaller complement of LANL 

personnel was required to be present. Both LANL and LLNL personnel were also stationed at 

the NTS and the PPG for extended periods of time. In addition to site testing, laboratory 

personnel were stationed at the NTS and at the PPG for extended periods of time. 

LANL had active participation in the assembly, testing, and disassembly of reactors for the 

Rover Project (LASL 1962, pg. 4). 

Although Project 400, the Rover reactor test program of LASL at NTS, is under 

the administrative direction of J-Division, other divisions are involved in the test 

series of Kiwi reactors, especially N-Division and H-Division. 

The evaluation of dose from LANL personnel participation in weapons and safety testing has not 

been considered in the TBD. Internal and external monitoring programs for those involved in 

testing should be compared with the potential for exposures at the test sites to evaluate the 

adequacy of monitoring by LANL and Nevada, and determine the potential for missed dose. In 

particular, how bioassay monitoring was handled by REECo for LANL employees with regard to 

short-lived fission products from fallout and recovery operations needs to be clarified. 

When individuals visited the NTS, they were asked to leave their LANL dosimeter at home. 

External dosimetry was supplied by REECo to individuals at the test site. Since the test site 

dosimeters were used in place of LANL dosimeters, the external dose obtained by REECo is 

subject to the same shortcomings as those documented in the Review of the NIOSH Site Profile 

for the Nevada Test Site (SCA-TR-TASK1-0006) (SC&A 2005a). In brief, these issues relate to 

lack of neutron dose data, potential neutron exposure during atmospheric testing, angular 

dependence of dosimeters, and uncertain status of bomb assembly workers. External monitoring 
 

 

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for the PPG and for Trinity was provided by LANL, thus requiring a further evaluation of the 

LANL dosimeters under these exposure conditions. 

Although there appears to be documented external exposure for those involved in testing at the 

NTS and the PPG through the NOO, there is no discussion of when this data is to be requested 

and how it is to be considered in dose reconstruction. The LANL TBD does not provide 

guidance on when to assume exposure as a result of test involvement, nor does it refer the dose 

reconstructor to the NTS TBD. In the case of Trinity, Amchitka, and the PPG, no TBD has been 

developed to characterize potential radiation exposure. 

Site experts indicated that bioassay sampling was done at REECo under special conditions. For 

example, during underground testing, site experts indicated that when there was an unexpected 

venting, REECo personnel were monitored immediately. If the results for REECo personnel 

were positive, the laboratory staff was asked to submit a bioassay sample. The delay between 

sampling of REECo personnel and laboratory personnel was about 1–2 days. The data from 

bioassay monitoring conducted by REECo are available in records maintained by the NOO. 

LANL has indicated that external dosimetry results from the test site have been integrated into 

their exposure database. There is uncertainty as to whether internal monitoring data collected at 

NTS, if any, have been incorporated into the LANL Bioassay Repository. SC&A was not able to 

evaluate whether this information was included, because they did not have access to the LANL 

Bioassay Repository database. 

In summary, the presence of LANL personnel at weapons testing sites should be evaluated to 

ensure employees were adequately monitored for internal and external hazards at the test sites. 

A missed dose methodology should be included for unmonitored or inadequately monitored 

workers who participated in weapons testing, safety experiments, and reactor tests. Where 

available, references to other site profiles are appropriate. 

5.5 ISSUE 5: NEUTRON DOSE RECONSTRUCTION APPROACH MAY RESULT 

IN UNDERESTIMATED DOSE 

Recommended neutron dose reconstruction assumptions and approaches in the current external 

dose TBD (ORAUT-TKBS-0010-6 (Widner 2005) could result in missed neutron doses. In 

addition, the recent recommendation of using n-p ratio values for neutron dose reconstruction 

needs further development and may suffer from lack of reliable early photon dose data and valid 

n-p ratio values. Some areas of concern are as follows. 

5.5.1 Neutron Doses Below 1 MeV and Above 3 MeV of Energy 

As at other nuclear facilities, LANL became aware of the NTA film’s under response to neutrons 

below 0.8–1.0 MeV around the late 1960s. The TBD, page 38, states that a study released in 

1978 showed that the average neutron energy field at TA-55 was approximately 200 keV, and 

that explains why very little neutron dose was observed using NTA film at the facility. The 

TBD, page 41, states that a study showed that the average neutron energy field at Los Alamos 
 

 

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Meson Physics Facility (LAMPF) in 18 locations was <100 keV and that explains why very little 

neutron dose was observed using NTA film at the facility. Furthermore, the TBD, page 43, 

states that a fission neutron energy spectrum (0.1 to 1 MeV) is to be assumed at all LANL 

reactors for dose purposes. This entire spectrum is essentially below the practical 1-MeV 

detection limits of NTA film used in the workers’ badges. 

While facility-specific neutron energy bands are provided in the TBD (e.g., on pages 47 and 72), 

it is not obvious that the dose reconstructor has any detailed correction factor or instructions 

available to correct for the unmonitored neutron doses resulting from neutrons with less than 

1 MeV of energy at the numerous facilities at LANL that produced neutron exposures through 

the years. Table 6-22 on page 48 and Table 6E-9 on page 71 of the TBD only provide wide 

ranges of neutron-to-gamma ratios (n/g) for three areas at LANL (Pu facility, Criticality 

Experiments, and Other operations). These tables are not very specific, giving a range for n/g of 

0.3 to 5.5. The only indirect mention of correcting for the under response of NTA film to lower 

energy neutrons is on page 47 of the TBD, where it states: “For years before 1980 at LANL, 

multiply annual photon dose (adjusted for any missed dose) times the neutron-to-photon dose 

factor from Section 6.4.4 and by the area-specific ICRP 60 correction factor shown above to 

estimate neutron dose.” Only a brief reference is made to n/g as a means to address unmonitored 

neutron dose, e.g., in the dose reconstruction guidance in Appendix E on page 71 of the TBD. 

If NTA neutron film data is to be used in DR, an area that needs to be investigated is the 

possibility of using overlapping NTA/thermoluminescent dosimeter (TLD) data to evaluate 

earlier missed neutron doses because of the 0.8–1.0 MeV neutron threshold of NTA film. This 

could provide some information on the amount of neutron dose missed at various work locations. 

5.5.2 NIOSH’s Recent Use of Neutron-to-Photon Ratio Values Instead of NTA Film Data 

A significant amount of resources went into neutron dose analysis of nuclear track plates (NTPs) 

and the NTA film results cited in the Occupational External Dose TBD, ORAUT-TKBS-0010-6 

(Widner 2005). However, in recent discussions,3

 NIOSH has indicated that the neutron dose 

reconstruction at LANL for 1943–1979 dose estimations should be based on the n-p method; 

relying on the n-p ratio values from 1980–2000 and photon measurements during 1943–1979. 

This method of using n-p ratio values to assign neutron doses can be used if direct neutron dose 

measurements are questionable or not available. However, to successfully do this, the photon 

dose measurements must be technically sound, and the n-p dose-equivalent values (implying 

knowledge of the neutron fields and energy spectra) for each given location and time period must 

be known with a reasonable degree of accuracy. The accuracy of the photon dose measurements 

is especially important when using the n-p method, because the total dose depends upon only one 

measurement (photon dose), rather than two independent methods (neutron and photon). The 

effects of an underestimation of the photon dose are doubled when using this method. In view of 

these facts, some issues of technical soundness need to be explored. 

3

 NIOSH and SC&A conference call, March 21, 2006. 
 

 

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5.5.2.1 Photon Dose Values Need Further Evaluation 

(1) The possibility needs to be addressed that the photon doses and n-p ratio values derived 

from methods used during 1980–2000, and their response to such variables as radiation 

energy, dose, directional geometry, etc., may not sufficiently match those of the early 

years, especially the 1940s, to allow current n-p ratio value to be applied to these earlier 

measurements (performed by different methods) to arrive at reasonable neutron doses. 

For example, the Occupational External Dose TBD, ORAUT-TKBS-0010-6 (Widner 

2005), page 36, states that a 1972 study showed that the film badge readings were about a 

factor of 3 higher than the TLDs. In addition, page 36 of the TBD states, “Hankins said 

that the method used to calibrate for plutonium did not consider the effect of the 

glovebox or buildup of 241Am in the gloveboxes.” Both of these statements are made in 

the TBD without stating what was done about the lower response of the TLDs to gamma 

dose or how Hankins’ statement affects the reported dose. Issues such as different beta 

and photon filters, or lack thereof, as well as film versus TLD, which could impact the 

resulting doses recorded through the years, should be investigated in detail to reveal any 

problem in using photon values to calculate neutron doses. Different dose measurement 

methods, which are acceptable in their own timeframe, may not be compatible with each 

other when separated by 30–50 years. This is not addressed in the TBD. 

(2) It could be difficult to obtain statistically valid photon dose values for 1943–1950, when 

relatively few workers were badged and a significant number of the results from those 

that were badged were not recorded and retained for future use. NIOSH needs to provide 

special procedures that cover this period. The photon dose values need to be based on 

realistic dose situations and not just on MDL values. This is especially important 

because not only will this dose affect the photon dose, it will determine the neutron dose 

using the n-p method. 

(3) Page 17 of the Occupational External Dose TBD indicates that the individual values for 

beta, photon, and neutron doses were recorded separately in the records. However, the 

last paragraph on page 2 of an earlier document (LANL 1956a) indicates that the total 

dose was reported as one figure in terms of rem from January 1953 to February 1956. 

This could present a problem sorting out the doses caused by different radiation types 

during dose reconstruction for this period. 

(4) Geometry factors were not addressed in the LANL TBDs, other than one statement in the 

Occupational External Dose TBD, ORAUT-TKBS-0010-6 (Wilder 2005), page 49, 

where it states that: 

Unfortunately, there is no definitive process to determine the exposure 

geometry for each LANL worker. Through discussions with Task 5 personnel, 

a simple 100% AP geometry will be assumed for all workers, even likely 

compensable workers. 
 

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This may not be claimant favorable considering that some technicians worked in unusual 

positions/situations, such as straddling accelerator components or working on tasks with their 

backs to the main radiation source. 

5.5.2.2 Neutron Dose Spectra May Be Different from 1943 to 1979 

LANL had many different operating areas with different neutron spectra and n-p ratio values 

over the period from 1943–1979. These values could be notably different from those of 1980– 

2000, because of changes in operations, regulatory standards, and instrumentation, as noted in 

the following observations: 

(1) The n-p ratio values listed in Table 6E-9 of the Occupational External Dose TBD were 

derived from the 1980–2000 dose data. Determining n-p ratio values requires knowledge 

of the neutron energy spectra, because the neutron dose equivalent has to be determined 

by some measurement. The neutron energy spectrum must then remain relatively 

constant over time to allow the use of the same n-p ratio values for a given location. 

However, the TBD, page 43, states that “Because neutron spectra have not been obtained 

for the LANL reactors, an assumption of 100% fission spectrum neutrons (0.1 to 1 MeV) 

is used.” NIOSH needs to illustrate how the n-p ratio values were derived, and why they 

should be considered sufficient to cover all types of situations at a given facility or 

facilities for which they are listed. 

(2) Table 6E-9 of the Occupational External Dose TBD only lists three locations (Pu facility, 

Criticality experiments >50m, and Others) and the new Occupational External Dose 

TBD, ORAUT-TKBS-0010-6, when issued, would apparently list 4. NIOSH should 

demonstrate that this limited set of n-p ratio values cover all the varied activities at 

LANL over the intended period of use, 1943–1979. 

(3) The need to have details concerning the workplace radiation environment is reiterated in 

the Occupational External Dose TBD, ORAUT-TKBS-0010-6 (Widner 2005), page 10, 

where it is mentioned that the calibration of the monitoring systems and similarity of the 

methods of calibration to sources of exposure in the workplace affects the accuracy and 

precision of the recorded dose. However, it appears that the "Other operations" n-p ratio 

values in Table 6E-9 of the TBD will cover everything from accelerators to moderated 

(i.e., alpha, n) neutrons to reactor neutrons with just one set of geometric means (GM) 

and 95th percentile values in the proposed new version of the LANL Occupational 

External Dose TBD. It does not appear reasonable to use only one n-p ratio value, 

considering that there was a wide range of neutron spectra present at LANL, ranging 

from high-energy neutrons around accelerators to thermal neutrons in the Omega 

Canyon. For example, an H-Division Progress report of 1952 observed that: 

It has been estimated that ninety percent of the neutron exposures at Omega 

Canyon has been due to thermal and slow neutrons. It has been suggested 

that the nuclear track plate results be increased by a factor of 8 to 10 in order 

to compensate for the discrepancy. (Shipman 1952) 
 

 

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The recommendation of the use of a single n-p ratio value needs additional investigation 

and support to be acceptable. Additionally, the maximum n-p ratio value of 2.4 as listed 

in the present Occupational External Dose TBD may not be sufficient for some situations 

in this wide variety of applications. It would be helpful to have Table 6E-9 expanded 

with a more detailed listing and guidance for its application, and illustrative examples in 

the TBD to establish its use of the present limited table entries. 

(4) Only a brief mention is made of n-p ratios in the dose reconstruction guide section in the 

Occupational External Dose TBD, ORAUT-TKBS-0010-6 (Widner 2005), Attachment E, 

page 71, in reference to unmonitored neutron dose. Missed neutron dose is covered in 

TBD, ORAUT-TKBS-0010-6, Appendix 6E, Section 6E.7 on page 71. However, the 

entire neutron dose reconstruction process during 1943–1979 is now proposed to be 

treated as a case of unmonitored workers as far as neutrons are concerned. In view of 

this, Appendix 6E, Section 6E.6 and 6E.7, on page 7 of the TBD needs more work. 

• 	 For example, in the Occupational External Dose TBD, ORAUT-TKBS-0010-6 

(Widner 2005), Appendix 6E, Section 6E.6 states that the unmonitored worker’s 

neutron dose is equivalent to the median neutron dose for monitored workers. This 

may not be the case for all workers as brought out in Issues #7 and #8 above. Some 

earlier workers could have been exposed to neutron doses greater than the average 

badged workers before strict badging requirements were set in place and some 

radiation hazards were recognized. 

• 	 The Tiger Team report of 1991 (DOE 1991) found problems with neutron monitoring 

for extremity doses. On page 4-181, it states the following: 

The most likely type of radiation dose to extremities in nonaccident 

situations at TA-55 is from neutron and gamma radiation. Extremity 

neutron doses are determined from ratios of gamma-to-neutron doses 

for whole body dosimeters. This ratio includes shielding and albedo 

effects that may not be applicable to extremities, especially for neutron 

doses. 

• 	 In Appendix 6E, Section 6E.7 of the TBD, it is stated that: 

To calculate the missed neutron dose, the reconstructor must first 

determine if the person worked near neutrons and the category of 

neutrons. This can best be determined by examining the work location 

records and whether a worker or others in the badge reporting group 

were assigned any neutron dose equivalent. If no neutron dose was 

assigned to the worker or coworker for several months, the dose 

reconstructor should assume that the person was not exposed to 

neutrons. 
 

 

 

 

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It is unclear if this statement is referring to each period of interest and if it would be 

evaluated for each missed neutron dose periods, or if it recommends using a very 

limited amount of data to make a decision concerning neutron exposures for a 

worker’s career. A worker’s individual working conditions, and the upper bounds to 

radiation exposures under these conditions, are more important than the co-worker 

data. It may be important to evaluate each period of missed dose during a worker’s 

career at LANL and his work situation during each missed dose period in conjunction 

with assigning unmonitored or missed neutron doses. 

All the above areas have an affect on neutron, and in some cases photon, dose reconstruction. 

Assuming radiation fields remain similar through time and were common to numerous facilities 

presents problems in performing technically sound and claimant-favorable dose reconstruction. 

In addition, assuming that any unmonitored worker received average doses, and any missed 

doses can be based on MDL values, as opposed to a specified radiation environment, could lead 

to an underestimate of individual doses. The present TBDs do not sufficiently demonstrate that 

the methods recommended and the data listed in the tables, such as n-p ratio values, are always 

applicable to the worker’s radiation environment and claimant favorable to prevent 

underestimate of worker doses. 

To apply n-p ratios to calculate missing neutron doses, the reliability and adequacy of the gamma 

monitoring program should first be evaluated. If the gamma doses of record are found to be 

flawed due to significant data integrity problems in the period in question, then it would appear 

that the derived neutron doses would also correspondingly lack integrity, with additional 

uncertainties introduced due to the use of an n-p ratio. 

5.6 ISSUE 6: TBD DOES NOT ADEQUATELY ADDRESS MISSED PLUTONIUM 

INTERNAL UPTAKES PRIOR TO 1970 DUE TO ABSENCE OF LUNG 

COUNTERS 

Section 5.2.1 of the Occupational Internal Dose TBD (Argall 2004) provides a section on 

“Missed Intakes;” however, it does not adequately describe the approach NIOSH intends to use 

to reconstruct a claimant-favorable dose for those individuals. In subsequent discussions with 

NIOSH,4

 it was learned that they intend to apply a dose of approximately 1/3 of the UPPU5 

average dose for workers of these early years. The use of one-third of the average value of the 

UPPU Club members is much less than the sensitivity of the monitoring capabilities in the early 

days. It is also known that inhalation of plutonium is not well quantified by urine analysis, and 

in some cases, transuranics are not detectable by this method for several years. Many of the 

early workers may not have had the opportunity for lung counting, which wasn’t available until 

about 1970 and thus, may have had uptakes that were never detected or measured. Papers by 

4

 NIOSH and SC&A conference call, March 21, 2006. 

5

 One small, but significant, group of workers at LANL was the UPPU club. This group was established by 

Wright Langham in 1951 and consisted of individuals who had accumulated a significant plutonium body burden 

and who agreed to be monitored periodically and continue to be monitored even past the end of their employment at 

LANL. 
 

 

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Langham et al. (1962) and Voelz et al. (1978) provide insight and substantiation of this issue, 

describing the difficulties of detection and monitoring in those early years at Los Alamos. 

The Occupational Internal Dose TBD supports the fact that, especially in the early years of 

LASL/LANL, many of the workers were not monitored and many were probably never 

monitored for uptakes. The plant was in its infancy and was on the leading edge of learning safe 

practices and inventing sensitive monitoring equipment for handling many of these 

radionuclides. As a result, the sensitivity for the first 10 to 20 years for measuring internal 

uptakes of these radionuclides was, in some cases, an order of magnitudes or more above the 

present day standards we consider acceptable. The TBD points out (Section 5.2.2, pg. 22) that 

“historically, emphasis was not on individuals being below the MDA, but rather being below the 

tolerance level.” The early tolerance level was equal to about 8.3 times the MPBB for plutonium 

at the time (a standard later accepted and used). The TBD recognizes and discusses examples of 

missed intakes, detection sensitivities, reporting limits, tolerance limits, nasal swipes, and 

MDAs, all of which are a part of the issue. In later years, with the development of whole-body 

and lung-counting solid state systems, LANL was much more rigorous in their use of MDAs, 

decision levels, and better sensitivity in their in-vivo and in-vitro measurements. 

Nonetheless, the Occupational Internal Dose TBD states in Section 5.1, page 11, that “only 

workers with a significant potential for exposure were monitored.” The use of the term 

“significant potential” should be considered noteworthy, given the fact that sensitivity was based 

on tolerance levels in the early days before whole-body counting came into use in 1955 and chest 

counting in 1970. The urinalysis sensitivity for detecting plutonium could not even meet the 

tolerance level of 5 μg (0.33 μCi or 8.3 times the later accepted MPBB beginning in 1951). The 

TBD notes in Section 5.1, page10, that, “early Health Group reports indicate contamination 

inside many of the respirators indicating improper storage and handling and poor fit during use.” 

The TBD further states the following in Section 5.2.1, page 16: 

Detection sensitivity was not a primary concern in the early years of operation of 

LASL. The concern was whether a tolerance limit was exceeded. Results below 

MDA were originally reported as “less-than” values (“LX.XX”) or 0 until the 

1980s, when actual results, positive and negative, were listed in the database. 

This leads to the problem experienced at other sites where workers realized significant intakes 

from chronic low-level air concentrations that went undetected even at today’s sensitive levels of 

detection. These types of exposures can lead to orders of magnitude greater potential exposure 

in workers exposed to such conditions. 

The LANL is to be commended on its treatment and emphasis on measurement statistics, such as 

MDA, decision levels, and uncertainties, dating from the 1980s to present. However, prior to the 

1980s there is concern by SC&A that the missed dose used for the dose reconstruction is not 

adequate or claimant favorable. Much of the discussion of MDA and chronic inhalation of 

Pu-239 in SC&A’s review of the RFP site profile (SC&A 2005b) applies to these missed dose 

concerns. 
 

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5.7 ISSUE 7: COMPLETENESS AND ACCURACY OF DOSIMETRY RECORDS 

NOT SUBSTANTIATED 

During site expert interviews with former workers, concerns were raised to SC&A regarding the 

completeness and accuracy of historic LANL radiation exposure records. The hierarchy of data 

used in the dose reconstruction process begins with the use of individual monitoring data as a 

priority. This is fundamental to the performance of dose reconstruction. The laboratory does not 

currently maintain a centralized, individual radiation exposure file similar to those maintained by 

other DOE sites. While such files at most DOE sites typically contain hardcopy internal and 

external monitoring results, incident or personal contamination records, secondary dosimetry 

results, whole-body count reports, etc., much of this data is not readily retrievable by LANL for a 

particular individual (See Attachment 2). The individual monitoring data provided to NIOSH, as 

cited by the site profile and applied in dose reconstruction, is pulled from a relational database 

compiled by Los Alamos. The absence of hardcopy records creates a heavy reliance on 

electronic data that has not undergone any independent validation regarding its completeness and 

accuracy. 

5.7.1 Validation of the Database 

The LANL and NIOSH, in a joint effort, compiled the LANL Bioassay Repository, which is a 

database inclusive of bioassay data, in-vivo measurements, and radiological incident reports, 

where applicable. The bioassay repository includes dose data for plutonium, americium, 

uranium, tritium, and polonium. Plutonium data extends back to 1944 (HSRPD 2005). Onsite 

expert interviews of radiological records personnel indicated that uranium and tritium were 

available for only some years (Attachment 2). 

The LANL Bioassay Repository database as a whole has been provided to NIOSH for use in 

dose reconstruction. Printouts from both the external and internal database are provided upon 

request for specific claimant information. In the absence of hardcopy records, there is a total 

reliance on information contained in the electronic records. 

In correspondence to SC&A, a former LANL subcontractor and site expert, Dr. Ken Silver, 

indicated that pre-1990 internal dosimetry data for plutonium and americium provided by LANL 

has not undergone verification and validation. This is confirmed by statements made in the 

LANL Bioassay Repository Report provided with claimant bioassay data that indicates that an 

effort was expended to verify and validate the electronic bioassay file, but the pre-1990 data may 

have been only partially reviewed: 

Although many hundreds of hours of effort have been expended, not all the V & V 

[verification and validation] could be accomplished where data was traced back 

to the original laboratory notebooks. The V & V that was accomplished focused 

on larger values or other records that might have dosimetric significance. From 

2000 to the present, virtually all the data is V & V’d; from 1990 to 2000 

approximately 85% is V & V’d; from 1944 to 1990 the V&V varies by nuclide, 

ranging from 90% to 25%. Virtually all records of dosimetric significance have 
 

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been V & V’d. LANL management and the NIOSH project manager have 

determined that the level of V & V is acceptable given the financial constraints of 

the Bioassay Data Repository Project. (HSRPD 2005) 

Dr. Silver also alleges in his letter that this data may have been modified in some fashion by 

LANL prior to transmittal to NIOSH (Silver 2006). Considering the importance of this data, 

further verification of data completeness and accuracy, especially for those results that were 

determined to have no “dosimetric significance” or were not included because of “financial 

reasons,” may be prudent. Likewise, it would be helpful to have the verification and validation 

process used and identified in the revised site profile. 

Furthermore, the Department of Energy’s 1991 “Tiger Team” Assessment of Los Alamos (DOE 

1991) found several deficiencies regarding accuracy and completeness of personnel radiation 

dosimetry. For instance: 

• 	 Historical radiation dose data, radiation dose data while working other than 

at ANL, and life-time radiation dose data on Radiation workers is not 

available at the Health Physics Operations Group. 

• 	 Accelerator personnel who work with depleted uranium components or with 

activated targets in the IBML have not been evaluated to determine whether 

they must wear extremity dosimeters. 

• 	 External radiation personnel dosimeters are exchanged monthly, site-wide, 

without regard to a worker’s potential for exposure. 

• 	 The existing LANL dosimeter cannot be used for determining low-energy beta 

or positron doses, such as thallium-204. 

• 	 Approximately 200 to 500 personnel dosimeters out of a total of 7500 are not 

returned at each exchange period for processing. 

• 	 The personnel dosimeter has a lower limit of detection of 10 mrem, resulting 

in dose of 9 mrem or less being recorded as zero. This practice results in a 

potential missed dose of 108 mrem per year. 

• 	 Extremity dosimetry is not worn when handling cast depleted uranium. 

Extremity doses from handling newly cast depleted uranium and its oxide can 

be significant. 

• 	 All the firing sites, including TA-36 and TA 17, LANL personnel are not 

evaluated for inclusion in the bioassay program. 

• 	 Not all personnel at the plutonium and depleted uranium facilities are 

evaluated for participation in the bioassay program to comply with DOE 

5480.11. 

• 	 Procedures for collecting processing and analyzing some bioassay samples do 

not ensure the accuracy, timeliness and quality of internal dose assessment as 

required by DOE 5480.11 (DOE 1991 – pg. 4-784). [ For example: It is 
 

 

 

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common industry practice to pick up tritium bioassay samples the same day 

they are submitted and process them within 48 hours...at LANL, tritium 

bioassay samples are picked up from field locations once a week (on 

Tuesdays). Normally, these samples are processed on the following Friday.] 

• 	 At the Los Alamos National Laboratory, there is no Health and Safety 

Division assurance that accurate monitoring of either external or internal 

exposures is accomplished. 

SC&A has determined that a second database containing Po-210 bioassay information exists; 

however, this database still requires verification and validation. The Po-210 bioassay 

information is linkable only to a name and not a Z-number. It is uncertain whether these data 

have been fully incorporated into the LANL Bioassay Repository. 

In summary, SC&A is concerned that total reliance on the LANL Bioassay Repository database, 

for which verification and validation has only been partially completed, may raise questions 

regarding the completeness and accuracy of internal dose estimates. As a compensatory process, 

SC&A is not aware of any effort to collect bioassay data known to be absent from this database, 

or to independently validate its reliability by comparing the electronic bioassay results with 

available logbooks, air sampling data, or other sources. 

5.7.2 Radiation Exposure Information in Medical Files 

NIOSH is provided with a printout of cycle-by-cycle external dosimetry information and 

bioassay data from exposure databases to conduct dose reconstructions. Additional data exist 

which is pertinent to the reconstruction of dose at LANL. In a report on the LANL radiological 

records program, reference is made to radiation data in “medical records:” 

Prior to January 1953, all exposures to beta and gamma radiation were reported 

to Medical Records for transposing into each individual Personnel Medical File. 

(LANL, 1956b) 

SC&A reviewed selected individual medical and radiological files during site visits to LANL. 

Records found in medical files included hazard reports, whole body and extremity dose 

information, nasal count data, personnel exposure record – airborne contamination reports, and 

incident reports. The hazard reports provide information on radiological hazards to which an 

individual was exposed during the course of their work (i.e., uranium, plutonium, polonium, 

beta, neutron x-ray, gamma or other sources of radiation). Routine and special nasal counts from 

the 1940s reside in the medical file. Reports on personnel exposure records and airborne 

contamination provide airborne concentration data for areas where an individual was assigned. 

Currently, NIOSH has requested that occupational x-ray and incident reports be provided from 

the medical record. The additional radiological information is not provided in the claimant 

package, which emphasizes the importance of verifying the completeness of information 

received for dose reconstruction. 
 

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The issue is further complicated by the existence of decaying medical records in the basement of 

the Los Alamos Medical Center (LAMC). Medical records in question may include historical 

patient files for not only the local community and families of workers, but for Los Alamos 

employees themselves. These records are stored at LAMC and in a nearby warehouse, and are 

under the control of the hospital. At the present time, these records are not readily retrievable 

due to the biological hazards associated with them. A preliminary review indicates that 

information pertinent to dose reconstruction is contained in these records. Considering the 

frequent inclusion of radiological files in onsite records, there is a potential that the medical 

records stored at the hospital also contain radiological information. Further evaluation on the 

pertinence of these records to energy employee dose reconstruction is warranted. Radiological 

data found in these files should be evaluated to ensure this data is reflected in the exposure 

databases compiled by Los Alamos. 

5.7.3 Human Radiation Experiments 

Human Radiation Experiments were conducted at Los Alamos from the early 1950s through 

1963. Radiation experiments included exposures to I-131, Na-24, tritium, Cr-51, Na-22, K-42, 

Rb-86, Cs-137, Cs-134, Fe-55, Fe-59, and Sr-85 (DOE 1995a). Some Los Alamos workers 

voluntarily participated in human radiation experiments. One former employee indicated that 

they had participated in a tritium ingestion study, as well as an ingestion study involving uranium 

carbide and Mn-54 in a capsule (DOE 1995b). Another LANL employee voluntarily took some 

Cr-51 and radioiodine labeled rose bengal (DOE 1995c). Ten LANL firemen orally ingested 

Fe-59 and were counted over a period of ten days (DOE 1995c). 

Information on the exposures of LANL employees from participation in human radiation 

experiments is not currently provided to NIOSH. Los Alamos recently discovered a source of 

records referred to as “individual research files,” which appear to contain information on 

radiation experimentation. These files are maintained separate from the medical and radiological 

records. The files are not limited to the experimentation, but include additional medical 

evaluations received by these personnel including supplemental x-rays. These individual 

research files, in addition to other information on worker participation in human radiation 

experiments, require further investigation to determine the number of claimants affected. Any 

files containing additional information on radiation exposures should be requested by NIOSH. 

5.7.3.1 Incidents 

Historic radiological exposure incidents were frequent at LANL, particularly in the early years. 

However, the site profile does not fully address the significance of such incidents, how they may 

have contributed to worker dose, and how they would be addressed by dose reconstruction (this 

issue has been addressed in other site profiles, albeit, inconsistently). It is not likely that NIOSH 

has specific information on who was monitored and who was not, how samples were collected 

during such incidents, and how these samples were handled and processed, especially in the early 

days. In the Site Description TBD, ORAUT-TKBS-0010-2 (Buddenbaum 2004), Table 2-4, 

pages 50–51, NIOSH has provided a list of 54 accidents and incidents. In addition, Table 5-22 in 

the Occupational Internal Dose TBD, ORAUT-TKBS-0010-5 (Argall 2004), pages 47–48, lists 
 

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an additional 45 accidents and incidents. Dr. Ken Silver, a LANL site expert, in his LANL 

comment report points out that: 

Two tables (2-4 and 5-22) in the site profile document list incidents that resulted 

in worker exposure to radiation. However, NIOSH and ORAU do not appear to 

have yet made comprehensive use of a voluminous Occurrence Reports Collection 

(ORC) located at TA-35 under the custodianship of John Voltin and William 

Inkret. Based on this author’s first-hand experience in the ORC at TA-35, it is 

apparent that Tables 2-4 and 5-22 of the site profile document do not take 

account of numerous worker contamination episodes. A lower bound estimate of 

64 net additional occurrences involving worker radiation contamination is 

derived for the years 1970–1980, 1985 and 1990 alone (Table 2), using this 

author’s research notes taken when he had access to the ORC at TA-35 from 1996 

to 1998. Extrapolation of this lower bound estimate to the entire period of 1944 

to 1991 translates into more than 230 occurrences involving worker radiation 

contamination for which documentation would be available if NIOSH and ORAU 

were to thoroughly utilize the ORC at TA-35. Illustrative examples of incidents 

documented in this collection but not included in the site profile document are 

listed in Table 3. In addition, Table 4 presents a similar list for years other than 

the 13 years noted above, drawing upon multiple sources including the LAHDRA 

repository at UNM’s Zimmerman Library and the files of the Joint Committee on 

Atomic Energy in Washington, D.C. (Silver 2005) 

While it is clear that judgment needs to be exercised regarding what accidents and incidents need 

to be reviewed and included in site profile characterization, it is important to identify available 

information regarding key accidents and incidents and assure their availability and use by dose 

reconstructors. As important, the site profile needs to evaluate this accident history for its 

implications to dosimetry adequacy and completeness of dose reconstruction. 

5.8 ISSUE 8: TBD DOES NOT ADDRESS POTENTIALLY MISSED AM-241 

INTAKES PRIOR TO THE MID-1990s 

Section 5.2.2 of the Occupational Internal Dose TBD (Argall 2004, pg. 22), states the following 

regarding participation of LANL workers in the americium bioassay program prior to the mid1990s: 

...participated in the americium bioassay program only if there was a potential 

for exposure to pure americium, and, prior to the mid-1990s, very few individuals 

submitted urine samples that were analyzed for the presence of 241Am. Samples 

were submitted in response to incidents involving exposures to sources of 241Am 

not contained in the plutonium mixture. 

The TBD further states, “Historically, emphasis was not on individuals being below the MDA, 

but rather being below the tolerance level” (Section 5.2.1, pg. 20). (This topic is discussed 

further in a separate discussion under Section 5.3). The tolerance level and MPBB for plutonium 
 

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started out at 5 μg or 0.33 μCi, which was 8.3 times the MPBB defined and used from 1951 

through 1989. 

It is noted in several places in the TBD that workers participated in the americium bioassay 

program only if there was a potential for exposure to pure americium. The explanation given for 

this in the TBD and in SC&A’s discussions with NIOSH/ORAU was that the plutonium at 

LANL in the early days was “newly processed” plutonium, and thus, had little time for in-growth 

of Am-241 from the Pu-241. This still leaves a couple of issues. One, the newly separated 

plutonium still usually had 50 to 100 ppm of Am-241 in the product, and, with normal weaponsgrade plutonium having approximately 0.5% by weight Pu-241, as noted in Table 5-6, page 19, 

of the TBD (Argall 2004), there is an in-growth of approximately 20 ppm of Am-241 per month. 

This leads to around 300 ppm Am-241 within a year, which is significant from a measurement 

standpoint. This becomes even more significant after 20 or 30 years of residence within the 

body after which the in-growth becomes 5,000 to 7,000 ppm Am. The dose from the Pu-241, 

Am-241, and U-237 alphas, x-rays, and 60 keV gamma rays become significant contributors to 

the lifetime dose to the individual. Second, LANL notes having received 6% and 12% Pu-240 

mixtures from at least one other reactor facility. This significantly changes the activity ratios of 

the Pu-241 that, in turn, increases the build-up and in-growth rate for the Am-241. This 

presented serious problems at other DOE sites around the country back in the 1960s. It is the 

concern of SC&A that exposures and possibly intakes of Am-241 may have been missed over 

the years as a result of the practice of monitoring for americium only if the worker had potential 

for exposure to pure americium. This concern is corroborated by statements in the TBD, as 

follows. 

The TBD (Argall 2004) states in Section 5.2.2, page 22, that: 

 ...there is an indication that workers participated in the americium bioassay 

program only if there was a potential for exposure to pure americium. (Argall 

2004) 

The TBD (Argall 2004) further states in Section 5.2.2, page 22, that: 

...prior to the mid-1990s, very few individuals’ submitted urine samples that were 

analyzed for the presence of 241Am. Samples were submitted in response to 

incidents involving exposures to sources of 241Am not contained in the plutonium 

mixture. (Argall 2004) 

The TBD (Argall 2004) also states that: 

 ...if the selected plutonium mixture, based on plutonium bioassay results, 

indicates the presence of americium, the absence of americium bioassay should 

not preclude the calculation of the dose from the americium contribution to the 

mixture. (Argall 2004) 
 

 

 

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This statement implies that some selected plutonium mixtures might indicate no presence of 

americium. The amount of americium may be small at initial intake; however, after years of ingrowth within the body after uptake of the plutonium, this may no longer be true. 

During the course of discussion between NIOSH, ORAU, and SC&A, there was the comment 

that americium and plutonium are linked inside the particle matrix and will remain bound and 

linked in the ratio of the initial material of intake. SC&A questions the technical validity of this 

statement based on the available scientific literature. The TBD (Argall 2004) in Section 5.2.1, 

page 21, notes a difference in plutonium-to-americium, particularly in the case of high-fired 

oxides, and this difference has been recognized and documented as far back as the 1960s (see 

Americium and Plutonium Urine Excretion Following Acute Inhalation Exposures to High-Fired 

Oxides (Hammond et al. 1968) and Two-Year Follow-Up Study of Several Acute Inhalation 

Exposures to PuO2 (Mann 1968). 

5.9 ISSUE 9: THE INTERNAL DOSE TBD LACKS A CLEAR MEANS TO ASSIGN 

DOSE TO UNMONITORED WORKERS 

The Occupational Internal Dose TBD, ORAUT-TKBS-0010-5 (Argall 2004) includes a 

statement attributed to Hempelmann et al. that working conditions at LANL were “deplorable by 

present-day standards” and that “in June and July 1945, over 50% of the laboratories had areas 

that routinely exceeded the maximum removable contamination level” (Hempelmann et al. 1973 

and Argall 2004). The TBD further states: 

The potential for unmonitored intakes was significant in the early years (1944– 

1946) for any site worker. Bioassay was provided only for those workers who 

were most exposed. However, because excretion of plutonium is continuous 

following an intake, significant intakes might have been identified on later routine 

bioassay samples with improved sensitivity for workers who remained at LANL. 

(Argall 2004) 

The TBD observes that as “bioassay sensitivities and respiratory protection equipment improved, 

the potential for intakes decreased” (Argall 2004). It goes on further to state that while large 

intakes that were unmonitored and undetected became increasingly rare after 1946, the 

“probability of small intakes is larger.” The TBD (Argall 2004) provides additional history that 

bolsters the case that such intakes would have been relatively common, given the significant 

number of “over tolerance” radiological occurrences even through the 1960s and the relatively 

loose programmatic requirements for who was required to receive routine or special bioassay, 

and loosely defined contamination control areas. Until 1970, the inclusion of workers in the 

bioassay program was at the complete discretion of the health physics monitor, leaving open the 

probability that workers were inappropriately not bioassayed even into the 1970s. 

Based on this history, SC&A is concerned about the historic number of unmonitored workers 

with the potential for uptakes of radionuclides. The TBD (Argall 2004) notes in (Section 5.1, 

pg. 11) that: 
 

 

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Excreta bioassay methods for determining internal exposures were developed in 

late 1944 for plutonium (fully implemented in April 1945) and polonium, in 1949 

for uranium, and in 1950 for tritium. Only workers with a potential for exposure 

were monitored. A survey taken in 1986 estimated that approximately 350 

persons had known burdens of plutonium. [Emphasis added] (Argall 2004) 

In Section 5.1, page 10, the TBD states that, “the potential for monitored and unmonitored 

intakes has existed throughout the history of the site” (Argall 2004). The text in Section 5.1, 

page 10 of the TBD, also points out that in these early days that: 

...research indicated that there was potential for work and casual encounters with 

plutonium and other radionuclides at various air concentrations or surface 

contamination levels, including levels that exceeded radiation exposure or control 

limits. Given that these operations were, in many cases, the first of their kind and 

that health physics practices were being developed and implemented at the same 

time plutonium processes were being brought online, some level of chronic or 

episodic intake during this period would be a reasonable assumption. 

A summary of some of the findings of the DOE Tiger Team Assessment conducted in November 

1991 (DOE 1991) included the following comments regarding the LANL internal dosimetry 

program. (The page numbers shown are the pages in the Tiger Team assessment). 

Not all personnel at the plutonium and depleted uranium facilities are evaluated 

for participation in the bioassay program. (pg. 4-183) 

A LANL employee was potentially exposed to substantial quantities of tritium 

contamination (i.e., oxide and organic bound) at the Ion Beam Facility. The 

facility does not provide proper controls and protection or require bioassay 

analyses for potentially exposed personnel. (pg. 4-385) 

In summary, at the time of the Tiger Team report in 1991, LANL did not have an adequate 

internal dosimetry program for four of the major categories of exposed workers; firing site 

workers, and workers potentially exposed to tritium, plutonium, and depleted uranium. An 

underlying reason may have been that three separate organizations were involved in staffing the 

bioassay program. 

The LANL internal dosimetry program involves staff from three separate 

organizations. The program lacks clear organization, defined responsibilities, 

and authorities. (pg. 4-783) 

Studies have not been performed at LANL work locations having major potential 

for worker internal exposure to airborne uranium and plutonium compounds to 

characterize the in vivo solubility characteristics of specific chemical forms. 

(pg. 4-785) 
 

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Interviews by SC&A have indicated that certain groups of individuals with access to radiological 

control areas, vaults, and special nuclear material (SNM) contaminated areas claim not to have 

been a part of the bioassay monitoring program. It was also claimed that certain groups of 

individuals were required to eat their lunches within these areas, and these individuals are among 

those that claim not to have been a part of the bioassay monitoring program (Attachment 2). It 

was further noted that during the dose reconstruction process for EEOICPA, records of security 

officers traveling to other DOE sites, such as NTS, were not included as a part of the LANL 

record and were not requested by LANL-DOE for submission to NIOSH. SC&A believes these 

issues and claims need to be addressed. 

SC&A is also concerned over the TBD’s speculative nature in addressing the provision of 

bioassay for students, postdoctoral researchers, and other temporary workers that may have had 

potential internal radionuclide intakes: 

Short-term workers, such as summer students, persons participating in 

postdoctoral work, and teachers, might not have fully participated in routine 

bioassay programs. These workers were monitored for internal exposure only in 

unusual circumstances. Near the terminations date, the worker might have 

received an in vivo count. The worker might have been required to submit an 

initial urine sample or have an initial in vivo count. [Emphasis added] 

(Argall 2004) 

It is clear from these statements, that there is no substantiation on how short-term workers were 

provided bioassay. 

Questions regarding data adequacy have largely focused on the adequacy of early occupational 

monitoring data. According to site experts, individuals who worked with 1 Ci of Am-241 or 

Pu-238/Pu-239 were placed on the urinalysis program (see Attachment 2). The potential for 

unmonitored intakes was significant from 1943–1946 for site workers. In the absence of early 

bioassay data, the TBD relies on maximum and average annual airborne concentrations to 

establish bounding conditions for chronic intakes. Airborne concentration data derived from 

LANL reports is not complete for all years of operations and radionuclides present, and in some 

cases is not specific to particular operations. For example, Table 5-20 of the TBD lists air 

sample values for DP (Defense Programs) West and DP East in 1949, which were involved in 

numerous operations. The air concentration values for I-131, fission products, and gross betagamma are limited for the 1940s and 1960s, and are not available for the 1950s. Maximum 

allowable concentrations (MACs) are used to bound doses in some cases; however, the TBD has 

not considered situations where airborne concentrations exceeded the MAC. During the early 

years, there were no consequences for exceeding these levels. At times, workers were exposed 

to airborne concentrations above the tolerance level for a radionuclide. MAC values may not 

represent a bounding condition in these cases. 

The TBD indicates that air monitoring is not an accurate predictor of intake quantity. In spite of 

this, there is no discussion of uncertainty related to the use of air monitoring and tolerance levels. 

Several technical studies, including the recent 2003 Y-12 study, Practical Use of Personal Air 
 

 

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Sampling (PAS) Data in the Internal Dosimetry Program at the Y-12 National Security Complex 

(Snapp 2003), and Nuclear Regulatory Commission’s NUREG 1400, Air Sampling in the 

Workplace (Hickey 1993), demonstrate that using air concentration data could lead to 

underestimating the worker intakes and subsequently the internal exposures. The Y-12 study 

shows as high as 10 times difference (underestimation) between intakes derived from bioassay 

data and intakes derived from air concentration data for uranium. In addition, the sensitivity of 

survey instruments, locations of the air sampling, and air flow studies of the buildings were not 

considered that could impact the accuracy of the air concentration data. The TBD instead applies 

a larger geometric standard deviation (GSD) (i.e., 5) to account for the uncertainties associated 

with estimating internal dose from air sampling. With the unknowns and shortcomings 

associated with the use of airborne concentration data for estimating missed dose, further 

evaluation should be provided to make sure this approach is bounding for unmonitored acute and 

chronic intakes. 

Given the above historic perspectives by both the TBD (Argall 2004) and SC&A’s references, it 

is clear why NIOSH concluded in the TBD that “the experiences of workers with monitored 

intakes cannot be used to develop a scenario [e.g., co-worker model] for workers who were not 

monitored,” but it is less clear how NIOSH intends to “derive potential intakes from removable 

contamination levels, tolerance and MAC air concentration levels, and airborne concentrations of 

significant radionuclides” (Argall 2004). First, such data is not necessarily available for many 

pertinent radionuclides to which workers were exposed (e.g., both primary and secondary 

radionuclides; see Section 5.1) and for many specific job locations; second, it is not clear, as 

emphasized by the TBD (Argall 2004), itself, who may have been exposed to potential internal 

source terms given the paucity of radiation controls at the site and lack of routine bioassaying of 

potentially exposed workers that existed well into the 1960s and 1970s. In short, for a long 

period extending into the 1960s, the TBD (Argall 2004) does not provide a plausible approach 

for assigning missed internal dose to unmonitored LANL workers, nor does it appear to be 

plausible to do so except for a few select radionuclides, such as plutonium and polonium. 

5.10 ISSUE 10: THE TBD DOES NOT ADEQUATELY ADDRESS POTENTIAL 

DOSE CONTRIBUTION FROM EXTERNAL HIGH-RADIATION EXPOSURES 

TO UNBADGED WORKERS 

SC&A is concerned regarding the Occupational External Dose TBD (Widner 2005) stated 

approach of assigning doses from the median values of co-workers or missed annual doses based 

on MDL values (in the 100s of mrem range) to unmonitored workers as recommended on pages 

49 and 65 of the TBD, when LANL’s operational history is replete with instances where the 

potential existed for exposures in the rem/hr range. These sources or incidents of radiation 

exposures at LANL that had the potential for high exposures include: 

• 	 The early experimental accelerators and n-p sources at TA-1 (Original Main Technical 

Area) mentioned in the Site Description TBD (Buddenbaum 2004, pg. 29) presented 

neutron and gamma exposure hazards: 
 

 

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A betatron used to study implosions was housed in the Gamma Building at 

TA-1. The intensity of betatron’s photon beam was reported to be 

25 R/minute at one meter and 0.16 R/minute at 12.5 meters (LASL 1946). 

The beam was directed outside and into a second building with no access 

controls in place.” [Emphasis added.] (Buddenbaum 2004, pg. 33) 

• 	 According to a LANL H-Division Progress Report of 1958 (Meyer 1958a), on January 3, 

1948, a high radiation background of 17 mr/hr was detected in D-Wing of the 

Administration Building. Subsequent investigation revealed that a 200 curie Co-60 

source was being used by J-10 on the third floor of A-wing. A reading of 120 mr/hr was 

detected on the sidewalk area and up to 18 mr/hr in adjacent rooms. It was found that a 

person had inadvertently walked in front of the beam and received 1.3R. 

• 	 The reactors and the Omega Stack at TA-2. The Site Description TBD (Buddenbaum 

2004, pp. 58 and 59) states the following: 

The exposure rate measurements made at head height at about 4 ft from 

the pit read more than 14 R hr-1 at the northeast corner and 2.2 R hr-1 at 

the southeast corner...An accident at the Omega Water Boiler on 

August 3, 1953, caused a temporary rise in the background to 100 R hr-1 

in the Reactor Room. No details were provided in the report about what 

specifically occurred. [Emphasis added.] 

• 	 The Site Description TBD (Buddenbaum 2004, pg. 59) also points out the 

following: 

On July 24, 1957, 120 cm3 of acid was added to the Water Boiler fuel 

solution. During this action, fission product material was inadvertently 

drawn into an evacuated line and deposited on the top of the reactor. 

Exposure rates as high as 20 R hr-1 were measured on the floor surface. 

[Emphasis added.] 

• 	 In an H-Division Progress Report of 1950 (Shipman 1950), it was stated that two 

experimenters walked through an unprotected fast [neutron] beam at the Water Boiler 

during a visit, resulting in a unusually high exposure on one of the worker’s NTP. It was 

not stated if the other workers were exposed to this unprotected beam or how long it had 

existed. 

• 	 The radioactive lanthanum experiments contained large amounts of radioactivity. The 

Site Description TBD (Buddenbaum 2004, pg. 32) states the following: 

The 140La sources prepared at Ten Site were usually in the range of 2,000 

to 4,000 Ci. Almost 2 million Ci of 140Ba had been handled at Ten Site by 

1963 when the RaLa program was terminated. 
 

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The decay of Ba-140 to La-140 to Ce-140 has an effective half life of around 14 days and 

emits a hefty 1.6 MeV gamma 96% of the time. These RaLa shots also released an 

estimated 226 mCi of Sr-90. 

• 	 The pulsed high-energy x-ray machines and associated large radioisotope sources (i.e., 

Co-60 sources up to 500 Ci, Ir-192 sources up to 100 Ci, and Cs-137 sources up to 30 Ci) 

at TA-15 (R Site), and “In 1947, TA-11 (K Site) had a 20-MeV betatron and a 500-mCi 

radium–beryllium source,” as stated in the Site Description TBD (Argall 2004, pg. 33). 

• 	 The operations of Los Alamos Power Reactor Experiments (LAPRE) I and II, with their 

associated leaks, created radiation fields upwards of several thousand roentgens per hour 

as cited by the Site Description TBD (Buddenbaum 2004), page 39. 

• 	 Neutron dose fields existed in, and surrounding, TA-18 during critical assembly 

operations as cited in the Site Description TBD (Buddenbaum 2004, pg. 46). The 

H-division Progress Report of 1955 states that on August 16, 1955 (Shipman 1955): 

Thirteen positions were checked, with five of the areas indicating almost 

prohibitive tolerance times of as low as 2 1⁄2 hours per week. The five 

areas are manned with personnel 100% of the time during working hours. 

The controlling or limiting factor was found to be due to thermal and 

intermediate neutrons. For this reason, persons outdoors or in thinwalled buildings receive a high exposure rate under these conditions. 

• 	 Neutron doses not monitored because significant neutron fields were not expected in that 

era of laboratory operations (e.g., accelerators, neutron generators, spontaneous-fission 

sources, critical assemblies, photo-neutron sources, alpha-neutron reactions, etc.). 

• 	 Waste handling and disposal activities, as noted in the Site Description TBD 

(Buddenbaum 2004, pp. 51–55), describe numerous waste treatment sites. However, 

much concern has been expressed in the past over workers who handled radioactive 

waste without proper monitoring because they were not considered radiation workers, or 

because the hazards were not recognized at the time. This was reiterated during recent 

worker interviews. This concern is with workers handling radioactive waste, not the 

environmental releases. 

Reference to these areas of high-potential exposures was included in the LANL TBDs and other 

documents, such as in the 1957 Group H-1 Annual Report, where it states: 

Certain types of work at the laboratory gave excessive difficulties in controlling 

external whole body radiation to personnel. These are: U-233 chemistry and 

fabrication, RaLa processing, experiments and water disposal, and the 

manipulation of critical assembly components. (Chelius 1958) 
 

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Also, it was stated on page 2 of the September 1958 H-Division Progress Report the following: 

A survey was made of the GMX-11 betatron. A report of the radiation levels was 

made to the operating group and the high radiation area was fenced. During the 

period August 14 through September 15 the calculated daytime dose to the Kappa 

Site area from activities at Pajarito Site was 0.297 rem. (Meyer 1958a) 

For example, the Occupational External Dose TBD, ORAUT-TKBS-0010-6 (Widner 2005, 

pg. 65) recommends assigning a median dose of 507 mrem for the year 1946 for unmonitored 

workers, and on page 68 (Widner 2005), it recommends assigning 240 mrem/year for missed 

doses for monitored workers who had missing data or zero entries on a monthly exchange basis. 

Compare this to the statement on page 33 of the Site Description TBD, ORAUT-TKBS-0010-2 

(Buddenbaum 2004), as quoted above, concerning betatron fields of 25 R/minute (1500 R/hr) at 

one meter and 160 mR/minute (9.6 R/hr) at 12.5 meters and the beam was directed outside 

without access controls in place. A brief 2–4 minute one-time exposure at 12.5 meters (40 ft) 

would exceed either the recommended missed or unmonitored assigned dose for a year. 

An example concerning high potential exposures from early reactors is provided on page 58 of 

ORAUT-TKBS-0010-2 (Buddenbaum 2004) where it states that, in 1950, exposure rates were 

2.2 to 12 R/hr around the Water Boiler reactor and that radiation fields were detectable as far 

away as the Trailer Village, even after reactor shutdown. Compare this to the recommended 

assigned median dose of 140 mrem/year for 1950 from page 65 of Occupational External Dose 

TBD, ORAUT-TKBS-0010-6 (Widner 2005) for unmonitored workers and 240 mrem/year for 

missed doses for monitored workers who had missing data or zero entries on a monthly 

exchange basis. Again, several minutes of exposure would exceed the recommended yearly 

assigned unmonitored or missed dose. 

Additional comparisons could be made for later periods; for example, the several thousand R/hr 

fields around the LAPRE I and II experimental reactors, which experienced leakage problems, 

ORAUT-TKBS-0010-2 (Buddenbaum 2004, pg. 39). A very brief exposure to these unexpected 

(at the time) high radiations fields would certainly overshadow the median or missed assigned 

doses as currently recommended. 

NIOSH should evaluate each claimant’s case to determine if the worker was involved in any of 

these high-exposure activities (not just accidents/incidents) before assigning the median 

unmonitored doses or missed doses based on MDL values. It has been contested that LANL 

over-badged its workers. This may have been true in some cases, but it would have been 

possible for unbadged workers to be exposed to high doses before the hazards were fully 

recognized; for example, when radiological controls were based on 10% of the radiation 

protection guidelines and badging was not as common. 

The area of waste handling is of specific importance because it has been an area of controversy 

in the Los Alamos community for years and needs to be fully addressed in the Occupational 

External Dose TBD (Widner 2005). In the present TBDs, it has not been demonstrated that 

technically sound monitoring practices for waste handlers were implemented throughout the 
 

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years, and that those workers who were not monitored should only be assigned doses based on 

median doses or MDL values as prescribed by the TBD approach. 

In summary, the current recommended approach of the TBD (Widner 2005) in assigning median 

and missed doses could result in substantially underestimating worker’s dose in a number of 

cases. 

5.11 ISSUE 11: UNMONITORED EXPOSURES OF ZIA COMPANY 

MAINTENANCE, CONSTRUCTION, AND FACILITY SUPPORT WORKERS 

NOT SUFFICIENTLY ADDRESSED 

Between 1946 and 1978, approximately 14,428 workers were employed by the Zia Company, 

the maintenance contractor at the LANL (Galke et al. 1992). Zia workers were involved in sitewide construction and maintenance of radiological facilities at LANL, as well as extensive 

radioactive waste management and disposal activities. While the internal dose TBD provides 

cursory information regarding Zia employees (e.g., on page 12, Table 5A-11 is referenced as 

providing a list of criteria and bioassay exempt job categories for plutonium bioassay), little 

information is provided regarding what is characterized in the TBD as a “separate” monitoring 

program. This is of particular concern because Zia workers were involved in almost all of the 

radiological operations at the laboratory during most of its history, and were frequently called 

upon to conduct jobs involving potentially significant internal and external radiation exposure 

potential including decontamination, radioactive waste disposal, and “hot” maintenance. 

Examples of the potential radiological risks to Zia workers are found in a 1977 history of 

radioactive waste disposal at LANL (Rogers 1977). 

• 	 1948 – The contamination on materials in these pits consists of all types of 

radioactive materials used at Los Alamos. Some of the known types of activity 

are: plutonium, polonium, uranium, americium, curium, RaLa [radioactive 

lanthanum], actinium, and waste products from the Water Boiler. No attempt has 

been made to keep the various materials separated. 

• 	 1948 – A fire broke out in Area B at approximately 10:20 a.m., May 3, 1948 

...When the fire department arrived [they] found sixty percent of the open portion 

of the dump ablaze and flames shooting approximately fifty feet into the air. The 

firemen had little trouble in subduing the blaze, but persistent efforts to put it out 

were to little avail because of the loaded condition of the dump area in which the 

blaze was confined. Dense, low hanging smoke prevailed in large volume 

...Because of the dense smoke which scattered throughout the area, due to the 

condition of shifting winds, all areas east and west of the dump, from the food 

warehouses to the DP laundry were evacuated of personnel. (Rogers 1977, 

pg. B-5) 

• 	 1949 – The waste disposal program requires three men. Two of these work on the 

contaminated truck and are furnished by the Zia Company. The third man is a 

CMR-12 monitor. The monitor supervises the handling of material...The 

equipment used consists of a truck and a sedan. The material in the pits is 
 

 

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covered once a week. This requires the use of a bulldozer and operator one day a 

week. (Rogers 1977, pg. B-4) 

• 	 1956 – ...collection of trash from laboratories was done in the following way. 

Zia janitors removed trash from host-waste cans and put trash into cardboard 

boxes. The boxes were then sealed and set outside the building for pickup by 

truck. (Rogers 1977, pg. C-8). 

• 	 1958 – Workers are off loading radioactive sludge drums from the waste 

treatment plant in Pit C area by hand – “...a few shovels of dirt are shoveled on 

top of the container so as to reduce the gamma radiation to less than 1 mrem/hr.” 

(Rogers 1977, pg. C-11). 

• 	 1959 – The practice of backing a truck up to the edge of a disposal pit and 

throwing trash off the rear was abandoned in 1959 when Pit 1 [containing 

plutonium, uranium and tritium wastes] was in use, after a man fell into the pit 

when the edge crumbled beneath him. (Rogers 1977, pg. G-16). 

• 	 1973 – Workers near Pit 1 were exposed to, “The tritium concentrations observed 

in the fill on Pit 1 are more than three orders of magnitude higher than this.”
 

[background concentrations] (Rogers 1977, pg. C-93) 

Epidemiological research underscores the paucity of monitoring data to support dose estimation 

for Zia workers. Studies of the Zia workforce, which include many Hispanics and Native 

Americans, have been found to be much less complete than for the UC workforce. In one study, 

personnel records were found to be available for 97% of the UC workers, but only 20% of the 

Zia workers; and urinalysis records were found to be available for 39% of the UC workers, but 

only four percent of the Zia workers (Wing and Richardson 2004). 

While the Zia monitoring program later had a computer program that locked out access to 

plutonium areas for workers not bioassayed within 425 days, it is not clear when this program 

was enacted. It is also unclear how this measure would have precluded workers from receiving 

uptakes and discontinuing employment, or moving to other radiological areas, and therefore not 

bioassayed. The site profile does not provide the requisite basis for determining what the 

potential missed and unmonitored dose may have been for the Zia workforce, given the spectrum 

of radiation sources involved and the varying site-wide work assignments to which they were 

assigned. For example, while Zia workers were bioassayed for Pu-238 and Pu-239, it is not clear 

when (or if) they were monitored for other internal emitters to which they were exposed. 

Furthermore, it is not clear whether external dosimetry was adjusted as maintenance and support 

workers moved from facility to facility and may have been exposed to varying neutron energy 

spectra. 

It is also not clear from the TBD how the 1978 policy was carried out to reduce the number of 

Zia employee bioassays to no more than 500. The TBD notes that the reduction included 

supervisors who “only performed inspections.” However, it is not clear what other job 

categories were included. SC&A wonders if this has an implication regarding potential 
 

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unmonitored internal dose. Likewise, the reliability of the dosimetry data in this so-called 

“separate” monitoring program is not addressed. 

Similar concerns apply to how dose estimation will be handled for unmonitored or inadequately 

monitored LANL security guards who likewise had site-wide access and were frequently in 

locations where potential internal and external radiation exposures were likely. Security 

performed patrols of the buildings and areas on foot, in vehicles, or on horse back. Building 

patrols required guards to check the outside of the building and perform internal walk-throughs 

of laboratory sites, including radiological areas. They had full access to all areas of the site, 

particularly in earlier years. Tours took them to various SNM storage areas as the machine 

shops, laboratories, assembly areas, firing sites, and near-critical assemblies. Many times 

officers were stationed in areas where nuclear weapons and components were out in the open. 

Officers responded to security alarms throughout the LANL facility. When these units alarmed, 

Patrol was required to enter the area and determine why the alarm was sounding. In some cases, 

when responding to alarms at facilities in TA-2, TA-16 (S Site), TA-41 (W Site), TA-18, and 

DP-West, they actually had to pass through laboratories to get to the alarm or vault, or be 

stationed inside the vaults until the incident was resolved. As the eyes and ears of the laboratory 

on off-hours, they were often the individuals who identified spills or unusual conditions. 

Other responsibilities included guarding SNM, escorting radioactive materials for scientists, and 

transporting of materials for testing. Security also inventoried material transported offsite, such 

as to the NTS, and participated in exercises involving detonation of nuclear weapons. 

The security force had regular potential for exposure to numerous radionuclides as well as 

external exposure hazards. External monitoring was routinely provided as verified by former 

guard interviews. It will be difficult, however, to associate exposure to a particular facility. This 

brings into question the appropriate n-p ratios and correction factors to be applied to dosimetry 

results. The completeness of the bioassay sampling is also questionable, based on the number of 

radionuclides they may have been exposed to during their rotations throughout the site. 

Exposure conditions and potential for exposure will differ between areas. For example, exposure 

conditions from material contained in a glove box would differ from those in a machining area 

where material is more likely to go airborne. 

Further consideration should be given to potential exposures and the adequacy of the internal and 

external monitoring data in relation to mobile workers, such as the Zia employees, security 

personnel, and other employees involved in site-wide activities. From interviews with 

NIOSH/ORAU staff, it was learned that additional bioassay information for Zia employees will 

be included in the next edition of the site profile. 
 

 

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5.12 SECONDARY ISSUES 

5.12.1 Secondary Issue 1: Cumulative Effect of Numerous Source Terms Not Adequately 

Addressed 

The Occupational Environmental Dose TBD, ORAUT-TKBS-0010-4 (Cehn and McDowellBoyer 2004), as written, fails to test the adequacy of evaluating the cumulative (additive) effect 

of numerous source terms at differing locations, which are in different Technical Areas (TAs). 

NIOSH has reported that recently released LANL documents that are associated with the 

Historical Document Retrieval and Assessment Project (LAHDRA) project are being used to 

review and determine whether additional information is available to fill gaps in the Occupational 

Environmental Dose TBD, ORAUT-TKBS-0010-4 (Cehn and McDowell-Boyer 2004) for 

sampling and effluent data. A revision to this TBD-4 is currently being developed and will 

utilize newly acquired information. 

To further clarify the content of the current TBD, NIOSH has offered that monitoring data do not 

distinguish the source of emissions, and therefore, to some measure, do evaluate additive effects. 

Although the ratioing method, currently being applied by NIOSH, does not address cumulative 

effects, the use of site-wide maximum intakes lessens the importance of these potential effects. 

SC&A believes that the lack of air monitoring stations, within a particular TA of known higher 

releases of a specified isotope, does not readily enable one to accurately estimate environmental 

dose. This is particularly true when using air monitoring data from an adjacent TA air 

monitoring station. It will be difficult for the dose assessor to accurately estimate environmental 

dose without accurate air monitoring data derived from a station proximal to the release point. 

To this extent, NIOSH has recently agreed that using emissions data to estimate air 

concentrations in another TA would not be appropriate. Recently released data from the 

LAHDRA project will be used to fill the gaps for sampling and effluent data. Depending upon 

the outcome of this review, NIOSH plans to revise the Occupational Environmental Dose TBD, 

ORAUT-TKBS-0010-4 (Cehn and McDowell-Boyer 2004). 

5.12.2 Secondary Issue 2: Validation of the LAHDRA Project Data Remains in Question 

The Occupational Environmental Dose TBD, ORAUT-TKBS-0010-4 (Cehn and McDowellBoyer 2004) has relied, to the extent possible, on data derived from the LAHDRA project, yet 

the validation of that data remains in question and is lacking sufficient effluent data for the years 

1945–1971. NIOSH/ORAU intends to validate this data against the missing effluent reports for 

1945–1971. Interviews of retired LANL personnel (see Attachment 2) suggest that essential 

data, as far back as 1958, does exist. 

NIOSH has responded by indicating that its earlier evaluation of effluent data back to the 1940s 

and 1950s found it was not reliable or mature enough for dose assessment at the time this 

Occupational Environmental Dose TBD was written and approved for dose assessor use. 
 

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Recently released additional LANL documents that are associated with the LAHDRA project, 

are being further reviewed to determine whether enough additional information is available to fill 

gaps in the TBD for sampling and effluent data. Another source of ongoing work involves 

development of co-worker data that could possibly be used in some instances to address 

unaccounted doses from releases. 

5.12.3 Secondary Issue 3: “Ratioing” Approach to Estimate Airborne Concentrations is 

Questionable 

The Occupational Environmental Dose TBD, ORAUT-TKBS-0010-4 (Cehn and McDowellBoyer 2004) fails to assure that the use of the “ratioing method” is adequate to estimate ambient 

air concentrations for Technical Areas (TAs) where limited ambient air monitoring data exists. 

The assumption that air concentrations are related to the ratio of effluents for nuclides in 

differing TAs has not been validated. 

NIOSH has reported that recently released LANL documents that are associated with the 

Historical Document Retrieval and Assessment Project (LAHDRA) are being used in their 

review to determine whether additional ambient air data is available to fill in the gaps in the TBD 

for sampling and effluent data which necessitated the ratioing approach. 

To further clarify the content of the current TBD, NIOSH has offered that since ambient 

monitoring data does not distinguish the actual source of emissions, then the application of a 

ratio approach based on actual effluent data may be appropriate. Also NIOSH feels the use of 

site-wide maximum intakes as a fallback would lessen the importance of the potential to 

underestimate dose. 

SC&A believes that the lack of air monitoring stations, within a particular TA of known higher 

releases of a specified isotope, does not readily enable one to accurately estimate environmental 

dose, using air monitoring data, from an adjacent TA air monitoring station. Similarly, the use of 

a ratio of effluent data or the use of a site maximum is problematic. It will be difficult for the 

dose assessor to accurately estimate environmental dose without actual ambient air monitoring 

data. 

To this extent, NIOSH has recently agreed that using emissions data to estimate air 

concentrations in another TA would not be appropriate. Recently released data from the 

LAHDRA project will be used to fill in the gaps for sampling and effluent data. 

Depending upon the outcome of this review, NIOSH plans to revise the TBD (Cehn and 

McDowell-Boyer 2004). 

5.12.4 Secondary Issue 4: Additional Occupational Medical X-rays should be Included in 

Dose 

The current guidelines, as presented in the reference OTIB-0006 (Kathren and Shockley 2005), 

go a long way in assuring that occupational medical exposures are included in determining the 

overall dose estimations for claimants. Unfortunately, the interpretation, to date, by the 
 

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contractor, ORAU, has not been necessarily applied conservatively to be claimant favorable. 

The Occupational Medical Dose TBD, ORAUT-TKBS-0010-3 TBD (Johnson 2004) assumes an 

interpretation, which has been also considered and applied at other sites, such as Rocky Flats and 

Hanford Plants. To this extent, the assumption that medical procedures are limited to only one 

pre-employment and other potential annual chest x-rays, as part of routine physical exams, may 

substantially underestimate worker medical exposure, when evaluating the totality of 

occupational medical exposure. 

In support documentation, OTIB-0006, Revision 3 (Kathren and Shockley 2005), it is concluded 

that other examinations may be included, such as special job exams (e.g., respiratory protection, 

beryllium workers, asbestos workers, etc.) and termination exams. The occupational medical 

TBD does not recognize this change from the previous Revision 2 of the OTIB-0006 (Kathren 

2003), and also incorrectly assumes that special chest radiography for respirator certification, 

beryllium and asbestos workers, and food handlers are accomplished as part of the annual 

physical. This is not documented in past medical protocols, and often was performed separately, 

at the request of the Medical Department, until the mid-1980s. Another factor not discussed in 

the TBD is the potential and impact of x-ray procedures utilized by medical authorities to do 

special screenings, and to evaluate the result of injury and trauma. 

The Occupational Medical Dose TBD makes the conclusion that one chest examination of a PA 

and LAT per year is probably limited to a small fraction of high-risk workers, especially after 

1992, as documented in Table 3.1 of the TBD. To the contrary, there is ample evidence that 

chest x-rays were provided on a voluntary basis to nearly all workers, as part of routine physical 

examinations. The majority of workers had chest x-rays as a routine at DOE sites until the mid1980s, when federal guidelines warning against routine screening were first being enforced. 

After discussion with NIOSH personnel, it was their decision to limit occupational medical 

exposure to those chest exams described above, and to assume all other exposure as part of 

worker background. SC&A believes such an interpretation is not claimant favorable to those 

most at risk. Our concern is that specified high-risk workers will likely receive compensation 

based upon a probability of causation (POC) from exposure to radiation and beryllium 

principally. Second, all radiation provides some risk, and arguably, is somewhat cumulative. 

These are not normal workers and warrant consideration of all forms of work-related x-ray 

exposure, to be claimant favorable. SC&A believes NIOSH should review its interpretation of 

included exposure, and should reasonably adopt a broader interpretation of medical dose, as 

provided in the OTIB-0006, Revision 3 (Kathren and Shockley 2005). 

Thus, it is not considered claimant favorable to limit occupational medical exams to one 

chest exam annually, unless medical records and protocols clearly limit the use of 

radiography to a small fraction of workers, which was not the case until the mid-1980s. 
 

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5.12.5 Secondary Issue 5: Beam Quality, Filtration, and X-ray Tube Output Not Well 

Known 

The Occupational Medical Dose TBD, ORAUT-TKBS-0010-3 (Johnson 2004) in Sections 3.2 

and 3.3 describes that little, if any, information exists upon which to establish beam quality for 

x-ray units in use from 1943 to 1984, when the site converted to Type III equipment. There is 

documentation to show that the General Electric KX810, in use from 1964 through 1984, did 

have initially 6.75 mm Al of added filtration, which was later reduced to 4.0 mm Al. In the 

absence of definitive tube output measurements, the TBD uses as default values, the DCFs 

derived from ICRP Report No. 34 (ICRP 1982). To calculate the dose from LAT chest x-rays, 

the TBD suggests using, as the LAT entrance skin exposure (ESE), a value that is 2.5 times the 

derived PA (ESE). These values are then applied to determine organ doses using Tables A.2 

through A.8 of ICRP Report No. 34. An issue of concern is that the DCFs are derived using a 

default HVL of 2.5 mm Al for Type 1 units, in use from 1943–1963. Another issue is that the 

unit, in use from 1964–1976, had added filtration of 6.75 mm Al, which is significantly higher 

than the maximum 3.5 mm Al taken from NCRP Report 102 (NCRP 1989, Table B.2). 

NIOSH believes that when no information is known about the energy spectrum, it is appropriate 

to use the Implementation Guide (NIOSH 2002a) as a basis document. However, SC&A is not 

able to verify that information provided in LASL 1972 and LASL 1976 are adequate to validate 

or support the assumption. NIOSH has agreed to search and add additional available references 

to help substantiate information depicted in Tables 3.2 and 3.3 of the Occupational Medical Dose 

TBD, ORAUT-TKBS-0010-3 (Johnson 2004). 

5.12.6 Secondary Issue 6: Lack of Maintenance, Collimation, and X-ray Protocol Data 

Increase Uncertainty 

The Occupational Medical Dose, ORAUT-TKBS-0010-3 (Johnson 2004) does not address the 

potential use of other forms of radiation exposure, other than x-ray units, to expose workers, to 

support medical injury diagnosis. This may involve use of isotopes, sealed sources, etc. The 

Occupational Medical Dose TBD, ORAUT-TKBS-0010-3 (Johnson 2004) is also deficient in 

that it does little to catalog the number, types of x-ray equipment, frequency of use, etc., 

discussed above. 

The less than average performance at LANL to perform routine and preventative maintenance 

during the 1943–1985 timeframe, suggests that routine maintenance of x-ray units is not likely, 

unless performed by an outside contractor. Unfortunately, no records exist to evidence 

maintenance, calibrations, and other such safety-related procedures. The lack of defined 

protocols and basis for approval of radiography procedures suggests that the use of radiography 

was not closely controlled. The Occupational Medical Dose TBD does not discuss the use of 

portable radiography to perform screenings and the potential for exposure of medical personnel 

or other workers without dosimetry devices being utilized. Interviews with past medical staff do 

suggest that portable x-ray units were not used. This is potentially an issue for the PFG unit, 

which was often van-mounted at other sites. Additionally, the TBD fails to document that 
 

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available x-ray units were not operated at greater than 80–90 kVp. To the contrary, Table 3-3 of 

the TBD indicates that the kVp after 1964 was set in a range from 96 to 102 kVp. 

The conclusion is that the Occupational Medical Dose TBD does little to reasonably 

document the variety of medical occupational exposures, and the lack of documentation 

on the type of equipment and the maintenance records does little to assure that a 

conservative and claimant-favorable estimation of dose is possible. This circumstance 

would suggest the need to reconsider a worst-case approach to establishing dose. 

5.12.7 Secondary Issue 7: Less than Optimal Collimation and Uncertain Substitute DCFs 

Impact Dose 

The Occupational Medical Dose TBD, ORAUT-TKBS-0010-3 (Johnson 2004) does not consider 

dose impacts due to less than optimal use of technology, such as using screens, grids, or bucky 

systems. The TBD does not consider these elements as potential contributions to uncertainty. 

The TBD does consider the potential contribution to dose that may have resulted in less than 

optimal use of collimation and offers substitute dose conversion factors (DCFs) for use by Dose 

Reconstructors (DRs) for selected exams, as presented in Table 3-8. The substitute DCFs are 

very limited in scope and can only be applied to exposure estimation for the gonads, eyes, and 

thyroid, as written. Unresolved is the concern that the DCFs are derived from ICRP (1982), and 

therefore, are not comparable, in terms of beam quality, which varies from unit to unit. These 

factors can contribute greatly to the dose to the chest and other organs, for units in operation 

prior to 1985, where little documentation exists. 

Uncertainty is defined in the TBD as being due to measurement error. This uncertainty includes 

variations in kilovoltage, tube current, timers, and the source to surface distance (SSD). This 

approach is quite similar to the uncertainty analyses documented in other DOE site profiles. The 

conclusion in this TBD, and others, is that an uncertainty factor of +30% should be used by dose 

reconstructors. 

SC&A agrees that the Occupational Medical Dose TBD conservatively estimates these essential 

aspects of an uncertainty review. Unresolved is the contribution to uncertainty in dose, due to 

other errors introduced by lack of quality controls in processing equipment and lack of adherence 

to established standard operating procedures (SOPs). A reasonable estimate of these 

contributions to uncertainty would be an evaluation of retake rates, per examination type. 

Interviews of LANL personnel suggest a 2.5% retake rate is appropriate for chest radiography. 

SC&A believes this estimate is very low, given that LANL used a higher kVp and shorter SSD 

protocols for many years, compared to other sites. NIOSH should revisit the potential for 

increased retake rates and evaluate its potential effect on dose, as part of its revision of this TBD. 

The Occupational Medical Dose TBD does not show that LANL applied dose minimization 

principles to reduce medical exposures. The document also does not assess or consider the likely 

exposure to workers who are referred to off-site medical facilities for follow-up. The TBD states 

that review of selected medical records and files did not reasonably show or match expected 
 

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x-ray exam frequency, and type of exam. Little evidence exists to document the number of x-ray 

exams provided to the average worker, or for special exposure needs. 

5.12.8 Secondary Issue 8: Missed Noble Gases and Mixed Activation Product 

Environmental Dose 

The most significant contributor to environmental dose is due to noble gases and mixed 

activation products. A review of estimates provided in Table 4-28 demonstrates that workers at, 

or near TA-53 (Los Alamos Neutron Science Center (LANSCE)) area might have received 

upwards of several hundred millirem unmonitored exposure during peak operation years after 

1976. NIOSH agrees that elevated exposures from noble gases is likely, but disagrees to the 

magnitude, since most of these releases occurred through elevated exhaust stacks. 

5.12.9 Secondary Issue 9: Lack of Equipment, Beam Quality, and X-ray Protocols Impact 

DCFs 

The Occupational Medical Dose TBD, ORAUT-TKBS-0010-3 (Johnson 2004) in Sections 3.2 

and 3.3 describes that little, if any, information exists upon which to establish beam quality for 

x-ray units in use from 1943 to 1984, when the site converted to Type III equipment. NIOSH 

believes that when no information is readily available about the energy spectrum, it is reasonable 

to use the assumptions for dose conversion factors (DCFs) which are presented in OTIB-0006 

(Kathren and Shockley 2005). However, SC&A is not able to verify that information provided 

in LASL 1972 and LASL 1976 is adequate to validate or support the assumption. NIOSH has 

agreed to search and add additional available references to help substantiate information depicted 

in Tables 3.2 and 3.3 of the TBD. The TBD also provides little documentation to support the 

assumed techniques and protocols applied to calculate the dose, which is mainly derived from 

Cardarelli et al. 2002, are accurate. The TBD states that for chest x-rays given during the 1970s, 

SOPs required both a PA and LAT view. It further indicates this was consistent to protocol in 

use, prior to 1960. SC&A inquired whether definitive protocol existed to validate that chest 

exams included both a PA and LAT through 1985. NIOSH has acknowledged that the lack of 

verifiable protocols is a problem, and has planned to search all available records and include 

pertinent records and references in a planned revision of this section of the Occupational Medical 

Dose TBD. 

The TBD is deficient in that little documentation exists to validate x-ray protocols, equipment 

maintenance and upkeep records prior to 1985. It uses information derived from the OTIB-0006, 

Revision 2 (Kathren 2003) to estimate dose impacts. Further dose estimations are derived from 

ICRP 34 and NCRP 102, and are not reflective of equipment and protocols used at LANL during 

1943–1984. 

The TBD further documents that photofluorography (PFG) units were routinely used at that site, 

from 1943 through 1957. PFG units were not considered when organ dose calculations were 

documented in ICRP 34 (ICRP 1982) and NCRP 102 (NCRP 1989), which forms the basis for 

organ dose calculations presented in the TBD, when documented use of an x-ray unit is 

available. 
 

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The TBD addresses the dose from PFGs as being conservatively estimated at 1.53 R, based upon 

a Hanford study by Rising and Soldat, 1959 (Rising and Soldat 1959). However, a recently 

revised version of OTIB-0006, Revision 03 (Kathren 2005) suggests that 3.0 rem per PFG exam 

is more appropriate. NIOSH agreed to provide further clarification of the dose applied to PFG 

exams from 1943–1956 in a pending revision to this section of the TBD. 

5.12.10 Secondary Issue 10: A Site-wide Atmospheric Model is needed for Accurate 

Environmental Dose 

There is no site-wide atmospheric model in use at LANL to assure an integrated environmental 

dose. The current Occupational Environmental Dose TBD, ORAUT-TKBS-0010-4 (Cehn and 

McDowell-Boyer 2004) recognizes this deficiency of lacking a site-wide model, which LANL 

has not put in place. SC&A questioned the need for such an atmospheric model and whether 

LANL could reasonably assess environmental dose, using only limited environmental data, as 

presented in the TBD. 

NIOSH has relied upon the use of data derived from the pre-existing LANL AIRNET network to 

estimate dose to the environment. AIRNET has a number of known past and current 

deficiencies, including the lack of air monitoring in all areas, especially on the northern plateau. 

To offset this lack of data, the Occupational Environmental Dose TBD relies upon any available 

emissions data to estimate maximum and median intakes of workers in environmental areas 

outside of restricted areas. This is problematic, in that emissions data is not easily converted to 

environmental dose when several emission points have to be considered. 

The TBD also evidences that effluent data before 1970 has not been identified and/or validated, 

and therefore, has relied on the incomplete air monitoring data as its basis. NIOSH has also 

indicated that recently released effluent data from the Los Alamos Historical Data Recovery and 

Assessment (LAHDRA) project will hopefully help to validate prior estimation. On the basis of 

that review, NIOSH expects to revise its TBD, as warranted. 

5.12.11 Secondary Issue 11: Frequency and Types of X-ray Exposures are Uncertain 

The Occupational Medical Dose TBD, ORAUT-TKBS-0010-3 (Johnson 2004) relies on 

frequency assumptions of other DOE sites. The assumption of two chest radiographs (PA and 

LAT) per year is not reasonably conservative, in that workers could essentially request an x-ray, 

or be subject to special screening exams. The frequency of screenings, and number and type of 

workers receiving x-rays varies from site to site, and within a site. 

The TBD in Section 3.2 provides no documentation or references to support the assumption that 

only a limited group of workers received annual x-ray exams after 1990. To the contrary, up 

until about 1985, most DOE sites performed chest x-rays on a voluntary basis. DOE medical 

program reviews documented, during the early 1990s, showed many sites still used chest 

radiography as a general screening exam. Most workers accepted chest x-rays, even though the 

job did not require it. Also, the assumption that workers in special exposure categories, such as 
 

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beryllium workers, were given chest x-rays only as part of their annual physical is not welldocumented. 

The TBD in Sections 3.2 and 3.5 does document that photofluorography (PFG) units were 

available from 1943–1956. The presence of PFG units at LANL for nearly 15 years suggests 

their potential heavy utilization, more than most other DOE sites. The PFG unit also provides a 

dose to the worker greater by a factor of 5–6, more than that delivered by conventional 

radiography. 

Also, the older version of the OTIB-0006, Revision 2 (Kathren 2003), upon which the TBD 

relies heavily, uses retake rates that average about 3%. The study referenced was based upon a 

large metropolitan hospital using highly trained technicians and well-maintained x-ray and 

processing units. A comparison review of federal facilities, such as by the Department of 

Defense (DOD) during the 1970s, using lesser-trained technicians (Federal regulations did not 

require technician certification.), showed that retakes sometimes ran up to 30% for abdominal 

exams, and often over 15% for chest radiography. Interviews of LANL staff indicated that 

retakes averaged 2.5% for chest x-rays until the Type V unit was installed. Although the PFG, 

by design, is less likely to require retakes, it is inherently much more dose-intensive. 

SC&A believes that the reported retake rate of 2.5% is anecdotal, and no documentation is 

provided to substantiate that estimate. 

5.12.12 Secondary Issue 12: Significant Estimates of Dose are Lacking for Some Episodic 

Releases 

The Occupational Environmental Dose TBD, ORAUT-TKBS-0010-4 (Cehn and McDowellBoyer 2004) details some of the known episodic releases, but fails to give significant estimates 

of dose. 

NIOSH has responded that the 1957 fire, which released plutonium into the environment, is an 

example of the lack of these estimates. The TBD also notes that there is a paucity of information 

regarding episodic releases, resulting in potential environmental contamination of workers. 

NIOSH believes the purpose of the TBD is not to provide estimates of dose, but rather offers 

estimates of source term to be used by dose assessors to estimate dose to individuals. Effluent 

data used would often include quantities for both routine and episodic releases; however, NIOSH 

recognizes current gaps exist in this information. Recently released LANL documents that are 

associated with the LAHDRA project are being reviewed to determine whether additional 

information is available to fill in gaps in the Occupational Environmental Dose TBD for 

sampling and effluent data resulting from episodic events. 

NIOSH has summarized that numerous references on the subject; Rogers (1977), LANL (1992), 

and DOE (1991) are all available. However, these documents do not provide sufficient 

quantitative information with which to estimate releases of radioactive materials. Rogers (1977) 

gives a good historical perspective on waste disposal activities, sites, and some incidents 

potentially causing releases to the environment at LASL/LANL, and provides many references 
 

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pertinent to air monitoring activities. These references were previously consulted in developing 

the current approach in the TBD to estimate intakes. The LANL (1992) reference is a RCRA 

Facility Investigation Work Plan for TA-49 (Frijoles Site), and thus describes the extent and 

location of contamination, but does not provide quantitative information for estimating historic 

episodic releases. Air monitoring results are available for this location after 1970. The DOE 

(1991) reference is the Tiger Team Assessment of LANL, and as such, does not provide a 

historical perspective on releases. 
 

 

 

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6.0 OVERALL ADEQUACY OF THE SITE PROFILE AS A BASIS FOR 

DOSE RECONSTRUCTION 

The SC&A procedures call for both a “vertical” assessment of a site profile for purposes of 

evaluating specific issues of adequacy and completeness, as well as a “horizontal” assessment 

pertaining to how the profile satisfies its intended purpose and scope. This section addresses the 

latter objective in a summary manner by evaluation of (1) how, and to what extent, the site 

profile satisfies the five objectives defined by the Advisory Board for ascertaining adequacy; 

(2) the usability of the site profile for its intended purpose, i.e., to provide a generalized technical 

resource for the dose reconstructor when individual dose records are unavailable; and (3) generic 

technical or policy issues that transcend any single site profile that need to be addressed by the 

Advisory Board and NIOSH. 

6.1 SATISFYING THE FIVE OBJECTIVES 

The SC&A review procedures, as approved by the Advisory Board, require that each site profile 

be evaluated against five measures of adequacy—completeness of data sources, technical 

accuracy, adequacy of data, site profile consistency, and regulatory compliance. The SC&A 

review found that the NIOSH site profile (and its constituent TBDs) for LANL represents an 

adequate accounting of the primary internal issues related to plutonium, uranium, polonium, and 

tritium exposures, as well as main external hazards from the reactor and accelerator facilities. 

The LANL site profile falls short in fully characterizing a number of key underlying issues that 

are fundamental to guiding dose reconstruction. In some cases, these issues may impact other 

site profiles. Many of the issues involve lack of sufficient conservatism in key assumptions or 

estimation approaches or incomplete site data or incomplete analyses of these data. Section 6.0 

summarizes the key issues. Detailed evaluation of these issues is provided elsewhere in the 

report. 

6.1.1 Objective 1: Completeness of Data Source 

The breadth of data sources used as a basis for the LANL site profile is evident in the 291 reports 

for Los Alamos National Laboratory in the Site Profile Research Database. Two hundred and 

seven reports were cited in the site profile references, while others served to provide confirmatory 

information. The NIOSH/ORAU team consulted health physics personnel with long histories at 

LANL who have extensive knowledge of key dosimetry historical processes and personnel 

monitoring data. Recently released LANL documents associated with the LAHDRA project are 

being reviewed by NIOSH/ORAU to determine whether information is available to fill gaps in 

the TBDs. A revision to the TBDs is under development and will utilize newly acquired 

information. Although SC&A was provided with a list of these documents, access to the 

particular documents was unavailable. 

The current version of ORAUT-TKBS-0010-4 was published with known data gaps before 1971 

in order to allow processing of selected LANL claims. NIOSH/ORAU realized at the issuance 

that a future planned revision would be necessary due to these existing data gaps. Revisions 

planned by NIOSH/ORAU will include additional information pertaining to environmental 
 

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monitoring and effluent data collected since the publication of this TBD, as well as any 

recommendations from SC&A. 

SC&A review of the LANL dosimetry records cited in the site profile from the standpoint of 

their adequacy and completeness, as well as their inclusion of known sources of LANL worker 

radiation dose information, indicates a lack of verification on the part of NIOSH to ensure 

records provided by the site are complete. Interviews with LANL workers have uncovered some 

additional sources of personal radiation exposure that may not routinely be provided by Los 

Alamos to NIOSH for individual claimants. LANL has limited the information provided to 

NIOSH from the individual medical records to x-ray reports and, in some cases, incident 

information. Medical records were found to contain an exposure section, which included hazard 

reports, whole-body and extremity dose information, nasal count data, personnel exposure record 

– airborne contamination reports, and incident reports. Similarly, some LANL workers 

participated in human radiation experiments up through the 1960s and should be given credit for 

radiation doses recorded in those records. All this data is directly relevant and should be 

reflected in dose reconstruction. Finally, while accidents and incidents are listed in the site 

profile, the site profile does not fully address the significance of such incidents, how they may 

have contributed to worker dose, and how they would be addressed by dose reconstruction. 

The hierarchy of data used in the dose reconstruction process begins with the use of individual 

monitoring data as a priority. This is fundamental to the performance of dose reconstruction. 

The laboratory does not currently maintain a centralized, individual radiation exposure file 

similar to those maintained by other DOE sites. While such files at most DOE sites typically 

contain hardcopy internal and external monitoring results, incident or personal contamination 

records, secondary dosimetry results, whole body count reports, etc., much of this data is not 

readily retrievable by LANL for a particular individual. The individual monitoring data provided 

to NIOSH, as cited by the site profile and applied in dose reconstruction, is pulled from a 

relational database compiled by Los Alamos. The absence of hardcopy records creates a heavy 

reliance on electronic data that has only undergone partial verification and validation regarding 

its completeness and accuracy. This is particularly of concern in the case of internal dose, as the 

source data is limited to information from the LANL Bioassay Repository database. This raises 

questions regarding the completeness and accuracy of internal dose estimates. 

Although the internal dose TBD recognizes the potential exposures from the radioactive 

materials at some test shot locations (e.g., lanthanum test shots in Bayo Canyon, TA-27 (Gamma 

Site), TA-11 (K Site), TA-4 (alpha site), TA-3 (South Mesa Site), TA-8 (Nondestructive 

Testing), and TA-40 (Detonator Firing Site), there are a number of firing sites included in the 

site description TBD that are not included (Argall 2004, pp. 70–77). These test sites include 

TA-5 (Beta Site), TA-7 (Gomez Ranch Site), TA-9 (Anchor Site East), TA-12 (L Site), TA-13 

(P Site), TA-14 (Q Site), TA-20 (Sandia Canyon Site), TA-67 (Pajarito Mesa Site), and TA-68 

(Water Canyon Site) (Buddenbaum 2004, pp. 12–16). Hydroshots were considered as a potential 

for exposure at IAAP, yet many of the test shot sites have been overlooked by the LANL TBD. 
 

 

 

 

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6.1.2 Objective 2: Technical Accuracy 

The site profile does not adequately address data insufficiency for impact and implications to 

early worker dose reconstruction. Information available for dose reconstruction in the early 

years is limited, inadequate, or in some cases not available. The internal dosimetry TBD 

approach is to use data from a later era to assign dose, or to use a hypothetical chronic intake for 

plutonium, polonium, and uranium where bioassay data is unavailable. The bioassay monitoring 

was limited to workers directly handling radionuclides, or had not been developed. Internal 

monitoring data for many radionuclides handled are not available until as late as the 1960s. The 

current TBD does not consider potential internal dose from radionuclides other than plutonium, 

polonium, and uranium during the 1943–1946 timeframe. The questionable completeness of 

external dosimetry records and the lack of complete documentation make assignment of coworker or average doses unfeasible. The lack of complete photon dosimetry data in the early 

days brings into question the ability to compute neutron dose by using the n-p method, which has 

been proposed by NIOSH. 

A number of deficiencies were identified with the internal dose TBD (Argall 2004) related to 

inadequate consideration of exposure and missed dose. Exposure to a number of these 

radionuclides was not given adequate, or in some cases, any consideration in the internal 

dosimetry TBD, although some are listed as facility-specific radionuclides handled in particular 

technical areas. The completeness of results for uranium, tritium, and polonium is uncertain. 

Guidance provided on the assignment of dose from Sr-90, Cs-137, Ba/La-140, P-32, C-14, 

Pa-231, radioiodine, and tritides is incomplete or inadequate to determine internal dose. These 

radionuclides may result in significant organ doses that are neglected. Reliance on partially 

validated bioassay data and claimant interviews to identify intakes from secondary radionuclides 

does not provide a sound basis for determining which individuals received dose from secondary 

radionuclides. Further research into the potential exposures from these radionuclides is needed 

to determine which workers may have been exposed, the quantities they were exposed to, and the 

potential internal doses from intakes. 

The Occupational Internal Dose TBD, ORAUT-TKBS-0010-5 (Argall 2004) lacks a clear means 

to assign dose to unmonitored workers. Given the historic inadequacies in LANL’s bioassay 

program even into the 1960s and 1970s, it is clear why NIOSH concluded in the Occupational 

Internal Dose TBD (Argall 2004) that “the experiences of workers with monitored intakes cannot 

be used to develop a scenario [i.e., co-worker model] for workers who were not monitored;” but 

it is less clear how NIOSH intends to “derive potential intakes from removable contamination 

levels, tolerance and MAC air concentration levels, and airborne concentrations of significant 

radionuclides” (Argall 2004). First, such data is not necessarily available for many pertinent 

radionuclides to which workers were exposed (e.g., both primary and secondary radionuclides; 

see Section 5.1 (Buddenbaum 2004, pg. 11) and for many specific job locations; second, it is not 

clear, as emphasized by the TBD, itself, who may have been exposed to potential internal source 

terms, given the paucity of radiation controls at the site and lack of routine bioassaying of 

potentially exposed workers that existed well into the 1960s and 1970s. SC&A finds that for a 

long period extending into the 1960s, the TBD (Argall 2004) does not provide a plausible 
 

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approach for assigning missed internal dose to unmonitored LANL workers, nor does it appear to 

be plausible to do so except for a few select radionuclides, such as plutonium and polonium. 

The current methodology outlined in ORAUT-TKBS-0010-6 (Widner 2005) may result in an 

underestimate of neutron dose. Neutron dose is determined from NTA film results and is 

modified with a correction factor. Some facility-specific neutron energy bands are provided; 

however, in some facilities, the entire spectrum is essentially below the practical 1-MeV 

detection limits of NTA film used in the workers’ badges. From the information in the current 

Occupational External Dose TBD, ORAUT-TKBS-0010-6 (Widner 2005), it is not obvious that 

the DR has sufficient detailed correction factor/instructions available to correct for the 

unmonitored neutron doses resulting from neutrons with less than 1 MeV of energy at the 

numerous facilities at LANL that produced neutron exposures through the years. 

The Occupational Medical Dose TBD, ORAUT-TKBS-0010-3 TBD (Johnson 2004) 

provides little documentation to support the assumed techniques and protocols applied to 

calculate the dose, which is mainly derived from Cardarelli et al. 2002, are accurate. 

NIOSH believes that when no information is readily available about the energy spectrum, 

it is reasonable to use the assumptions for DCFs that are presented in the Implementation 

Guide. 

The Occupational Medical Dose TBD, ORAUT-TKBS-0010-3 (Johnson 2004) does consider the 

potential contribution to dose that may have resulted in less than optimal use of collimation and 

offers substitute dose conversion factors (DCFs) for use by DRs for selected exams, as presented 

in Table 3-8. The substitute DCFs are very limited in scope and can only be applied to exposure 

estimation for the gonads, eyes, and thyroid, as written. Unresolved is the concern that the DCFs 

are derived from ICRP (1982), and therefore, are not comparable, in terms of beam quality, 

which varies from unit to unit. These factors can contribute greatly to the dose to the chest and 

other organs, for units in operation prior to 1985, where little documentation exists. 

The Occupational Environmental Dose TBD, ORAUT-TKBS-0010-4 (Cehn and McDowellBoyer 2004), as written, fails to test the adequacy of evaluating the cumulative (additive) effect 

of numerous source terms at differing locations, which are in different Technical Areas (TAs). It 

has relied, to the extent possible, on data derived from the LAHDRA project, yet the validation 

of that data remains in question and is lacking sufficient effluent data for the years 1945–1971. 

Interviews of retired LANL personnel (see Attachment 2) suggest that essential data, as far back 

as 1958, does exist. SC&A believes that the lack of air monitoring stations, within a particular 

TA of known higher releases of a specified isotope, does not readily enable one to accurately 

estimate environmental dose, using air monitoring data, from an adjacent TA air monitoring 

station. It will be difficult for the dose assessor to accurately estimate environmental dose 

without accurate air monitoring data derived from a station proximal to the release point. 
 

 

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6.1.3 Objective 3: Adequacy of Data 

Questions regarding data adequacy have largely focused on the adequacy of early occupational 

monitoring data. According to site experts, individuals who worked with 1 Curie of Am-241 or 

Pu-238/Pu-239 were placed on the urinalysis program (See Attachment 2). The potential for 

unmonitored intakes was significant from 1943–1946 for site workers. In the absence of early 

bioassay data, the Occupational Internal Dose TBD (Argall 2004) relies on maximum and 

average airborne concentrations to establish boundary conditions for chronic intakes below the 

detectability of the time. Airborne concentration is not available for all years of operations and 

radionuclides present, especially fission products. There is a large amount of uncertainty in 

calculation of early internal doses resulting from inadequate or incomplete monitoring data, 

including air concentration data, which casts doubt on the feasibility to reconstruct internal dose 

prior to the establishment of routine, reliable bioassay methods. 

According to the Occupational External Dose TBD (Widner 2005), external radiation personnel 

monitoring did not include adequate methods to monitor beta, gamma, and neutrons until around 

1951 (i.e., see Table 6-5, pg. 21 and Table 6-7 on pg. 28). Some gamma doses were measured in 

the early days, but beta, gamma, and especially neutron doses were not adequately or routinely 

monitored. There are concerns related to the measurement of early exposures and the 

consistency in which they were documented. For example, the Occupational External Dose TBD 

states in Section 6.2.1.5, page 19, that dosimetry measurements made prior to August 1950 

apparently did not make it into long-term records for the GMX-1 group. 

NIOSH has indicated that its earlier evaluation of effluent data back to the 1940s and 1950s 

found it was not reliable or mature enough for dose assessment at the time this Occupational 

Environmental Dose TBD, ORAUT-TKBS-0010-4 (Cehn and McDowell-Boyer 2004) was 

written and approved for dose assessor use. Recently released additional LANL documents that 

are associated with the LAHDRA project, are being further reviewed to determine whether 

enough additional information is available to fill gaps in the Occupational Environmental Dose 

TBD, ORAUT-TKBS-0010-4 (Cehn and McDowell-Boyer 2004) for sampling and effluent data. 

6.1.4 Objective 4: Consistency Among Site Profiles 

An extensive comparison was performed by SC&A to compare and contrast the methodologies 

used in the LANL site profile and other site profiles reviewed to date. These comparisons focus 

on the methodologies and assumptions associated with dose assessments and the derivation of 

values used to obtain a probability of causation for individual claimants. A detailed analysis is 

provided in Attachment 7 to this report. 

The site description provides a comprehensive evaluation of activities that occurred at the 

different technical areas, and some of the potential hazards associated with these operations. 

This valuable data is not carried through to the other TBDs, such as the environmental and 

internal dose TBDs. For example, many of the weapons firing sites mentioned in the site 

description are not mentioned in the environmental and internal dose TBDs. Some mention of 

these sites is warranted as they have been identified as handling radioactive material. 
 

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The basic default values assigned for determining medical exposure are relatively consistent 

among site profiles. The site profiles do not always apply the same revision of this ORAUTOTIB-0006, as is the case with the LANL site profile, which can be corrected in subsequent 

revisions of TBDs. A more consistent approach to determining when dose from PFG is to be 

assigned is needed in cases where there is an absence of site-specific information. Other 

deviations from the standard assumptions are based on site-specific information. 

Review of site profiles to date indicates that the NIOSH/ORAU team has not come to a 

consensus on what components should be considered in the environmental dose. The analysis 

considered internal dose from onsite atmospheric radionuclide concentrations, limited evaluation 

of internal dose from resuspended soil, and ambient external exposure. As acknowledged by 

NIOSH/ORAU, considerable investigation into dose from soil resuspension is needed with the 

numerous hydrotest locations at LANL and the heavy agitation of soils during D&D. As with 

many of the site profiles, there is no consideration of potential exposure from liquid effluents at 

LANL. 

In the case of environmental dose, Am-241, H-3, I-131, Pu-239, Th-232, U-234, MFPs (i.e., 

Sr-90), and P/VAPs (i.e., Ge-68) were considered for the site-wide maximum exposures, which 

are applied when work location is unknown. Ambient external dose as well as dose external 

dose from Ar-41 was considered. External dose from Ar-41 was specific to TA-2. Be-7, P-32, 

As-72, Br-76, Rb-86, Cs-137, Cs-138, La-140, Ir-192, Hg-203, and Th-234 were considered; 

however, the dose contributions were <10E-5 Sv/year, so this dose was neglected. Other 

radionuclides, such as Po-210, I-131, Xe-131, Kr-85, Ra-226, Np-237, C-11, N-13, I-133, I-135, 

and U-233, were not considered even in the screening assessment, yet they were mentioned in 

the site description. 

During the Y-12 Special Exposure Cohort (SEC) petition review, considerable attention was 

given to radionuclides generated by the Oak Ridge National Laboratory (ORNL) Isotopes 

Production Group and potential exposures to Y-12 workers from these activities. The LANL 

TBD has not included a discussion on the numerous radionuclides produced by the accelerators, 

such as medical radionuclide production. Depending on the quantities and types of radioactive 

material produced, this may affect internal dose. 

The LANL Internal Dosimetry TBD simply refers to the specific guidance provided in OCASTIB-003 (OCAS 2003) when calculating internal dose from MT or OBTs. This is a general 

procedure on how to use IREP to calculate tritium dose from tritides and OBTs with no LANL 

specific guidance or general direction on solubility, particle size, or other pertinent internal dose 

calculation factors. With the Mound Internal Dosimetry TBD (Millard 2004), there was a more 

detailed discussion regarding MT including appropriate lung clearance classes. The SRS 

Internal Dosimetry TBD (Scalsky 2005) and associated TIBs fail to treat the topic of dose from 

exposure to OBT and MT at all. Given that tritium processes and the special tritium compounds 

handled at these sites were the same or similar, a consistent methodology is appropriate. 

The LANL external dose TBD (Widner 2005) applies an area-specific neutron energy 

distribution for years after 1978. For years prior to 1980, the annual photon dose is multiplied by 
 

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an n-p ratio to obtain the neutron dose. The TBD has derived three n-p ratios for the plutonium 

facilities, criticality experiments (> 50 m distant), and other operations. The SRS TBD 

distinguishes neutron energies and n-p ratios for reactors, fuel fabrication, plutonium production, 

and radionuclide production and calibration (Scalsky 2005). The INEEL TBD considers the 

reactors, the processing plant, waste handling operations, calibration sources, and uranium 

handling (Rohrig 2004). Neutron energy spectra and n-p ratios for Pu-238 and P-239 operations 

are segregated at SRS (Scalsky 2005). The categories used in the LANL TBD lack the detailed 

analyses seen in other TBDs. Further evaluation of n-p ratios should include more specific 

categories including neutron sources (RaBe, Cf, etc.), accelerators, early subcriticality 

experiments, initiator development, and neutron spectra from alternate fissile materials. The 

relative impact of further differentiation of n-p ratios will depend on the particular neutron 

source. 

The Y-12, SRS, and Hanford TBDs base their default exposure geometry on the compensability 

or non-compensability of the claim. The Mallinckrodt Chemical Worker (MCW) and RFP TBDs 

based default exposure geometries on job titles. Both the LANL and the Idaho National 

Engineering and Environmental Laboratory (INEEL) TBDs choose to default to 100% AnteriorPosterior (AP) exposure. Further evaluation of exposure geometry for photon and neutron 

exposure should be evaluated for LANL workers to determine if 100% AP geometry is 

appropriate for all LANL workers. The NIOSH/ORAU team should consider development of a 

consistent default assumption for exposure geometry in all site profiles. 

6.1.5 Objective 5: Regulatory Compliance 

SC&A reviewed the site profile with respect to Objective 5, which requires SC&A to evaluate 

the degree to which the site profile complies with stated policy and directives contained in 

42 CFR Part 82. In addition, SC&A evaluated the TBDs for adherence to general quality 

assurance policies and procedures utilized for the performance of dose reconstructions. NIOSH 

has complied with the hierarchy of data required under 42 CFR Part 82 and its implementation 

guides. As mentioned above, quality assurance with respect to claimant-specific information is 

lacking, and further consideration should be given to the evaluation of records provided by sites, 

and how the requests for these records are communicated to the sites. In essence, if something is 

not explicitly requested, it will not be provided. 

6.2 USABILITY OF SITE PROFILE FOR INTENDED PURPOSE 

SC&A has identified seven criteria that reflect the intent of the EEOICPA and the regulatory 

requirements of 42 CFR Part 82 for dose reconstruction. Because the purpose of a site profile is 

to support the dose reconstruction process, it is critical that the site profile assumptions, analytic 

approaches, and procedural directions be clear, accurate, complete, and auditable (i.e., 

sufficiently documented). SC&A used the following seven objectives to guide its review of the 

LANL Site Profile TBDs to determine whether it meets these criteria: 

Objective 1 − Determine the degree to which procedures support a process that is expeditious 

and timely for dose reconstruction. 
 

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Objective 2 − Determine whether procedures provide adequate guidance to be efficient in select 

instances where a more detailed approach to dose reconstruction would not affect the outcome. 

Objective 3 − Assess the extent to which procedures account for all potential exposures and 

ensure that resultant doses are complete and are based on adequate data. 

Objective 4 − Assess procedures for providing a consistent approach to dose reconstruction, 

regardless of claimants’ exposures by time and employment locations. 

Objective 5 − Evaluate procedures with regard to fairness and the extent to which the claimant is 

given the benefit of the doubt when there are unknowns and uncertainties concerning radiation 

exposures. 

Objective 6 − Evaluate procedures for their approach to quantifying the uncertainty distribution 

of annual dose estimates that is consistent with and supports a DOL probability of causation 

estimate at the upper 99% confidence level. 

Objective 7 − Assess the scientific and technical quality of methods and guidance contained in 

procedures to ensure that they reflect the proper balance between current/consensus scientific 

methods and dose reconstruction efficiency. 

6.2.1 Ambiguous Dose Reconstruction Direction 

Direction provided in the site profile as a stand alone document can be confusing, and in some 

cases directions are inconsistent throughout a particular TBD. With the supplemental TIBs in 

the case of internal, external, and occupational medical dose, the approach is somewhat more 

clearly defined. 

The conditions for application of environmental dose to LANL employees are not clearly defined 

in the introduction of the Environmental TBD, as is usually the case with other TBDs. There are 

recommendations for usage throughout the TBD, but concrete direction for which workers 

receive environmental dose is lacking. 

Discussions on Sr-90, Cs-137, Ba/La-140, I-131, thorium, and I/Xe-135 are included in the 

internal TBD; however, a proposed method for identifying individuals potentially exposed to 

these radionuclides and assigning them a missed dose is absent from the TBD. The TBD 

recognizes that strontium dose reconstruction can only be done if strontium bioassay is available. 

There is limited guidance on how to assess intakes from tritides, P-32, C-14, and Pa-231. The 

TBD directs the DR to assess dose from Ac-227, P-32, C-14, thorium, and Pa-231 only when 

there is an indication that the worker had a potential for interaction with the radionuclide 

(pg. 32). There is mention of Ra-226 and radon in Table 5A-10 (pg. 70). Radon was specifically 

addressed in the Mallinckrodt Chemical Workers (MCW) and Fernald TBDs, where K-65 

residues with high concentrations of Ra-226 were handled, yet the LANL TBD fails to consider 

radon exposure from the cooking off sources or leaking of radium sources in TA-1. 
 

 

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6.2.2 Inconsistencies and Editorial Errors in the Site Profiles 

Errors were identified through Verification and Validation efforts in three tables of the 

Occupational Environmental Dose TBD (Cehn and McDowell-Boyer 2004). These errors are 

attributed to data transcription issues. Corrections have been made by the NIOSH/ORAU team 

to Tables 4-2, 4-10, and 4-15 and are available in Attachment 5 of this review. There were no 

cases of significant increases in intakes. In fact, the changes led to a lowering of estimated 

intakes, particularly for H-3 at TA-3. 

6.3 UNRESOLVED POLICY OR GENERIC TECHNICAL ISSUES 

A number of issues were identified that are common in the LANL and other site profiles 

reviewed to date and, in some cases, represent potential generic policy issues that transcend any 

individual site profile. These issues may involve the interpretation of existing standards (e.g., 

oro-nasal breathing), how certain critical worker populations should be profiled for historic 

radiation exposure (e.g., construction workers and early workers), and how exposure itself 

should be analyzed (e.g., treatment of incidents and statistical treatment of dose distributions). 

NIOSH indicates that it may develop separate TIBs in order to address these more generic issues. 

The following represents those issues identified in the LANL and previous Site Profile reviews 

that in SC&A’s view represent transcendent issues that need to be considered by NIOSH as 

unresolved policy or generic technical issues. 

Direction on the applicability of the TBD and/or TIBs to individual dose reconstructions is 

absent. 

Mobility of work force between different areas of the site should be addressed. Site expert 

testimony that many workers moved from one plant to the next is a complicating factor. 

Establishment of an accurate worker history is crucial in such cases. This will be especially 

difficult for family-member claimants. 

(1) Statistical techniques used in the application of the data to individual workers should be 

further considered and substantiated. 

(2) Dose from impurities and/or daughter products in radioactive material received and 

processed at sites should be assessed as a contributory exposure source. 

(3) The significance of various exposure pathways and the assumptions made that influence 

dose contributions need to be considered (most notably) for solubility, oro-nasal 

breathing, and ingestion. 

(4) Analysis needs to be performed regarding how “frequent or routine incidents” should be 

addressed, given the possibility that such “spike” exposures may be often missed by 

routine monitoring as a function of how often and in what manner it was conducted. 

(5) Availability of monitoring records for “transient or outside workers,” e.g., subcontractors, 

construction workers, and visitors who may have potential exposure while working on or 

visiting a facility should be ascertained. 
 

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(6) Dose to D&D workers should be assessed. Many facilities have large-scale D&D 

operations, which extend back many years. Decontamination and decommissioning 

operations often requiring working in unknown situations, which may provide unique 

exposure situations. 

(7) Dose reconstruction for occupational medical exposures remains incomplete. NIOSH 

needs to reconsider the definition to include all forms of radiation medical exposure, to 

ensure its considerations are claimant favorable. 

(8) Dose reconstruction for workers involved in nuclear weapons testing who were employed 

by a site other than the test site. 

(9) Quality Assurance on records provided by the site to the NIOSH/ORAU team is 

necessary to ascertain whether complete information is being provided. 
 

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Chelius, L. 1958. Explanation of overexposures To External Whole Body Radiation For 1st 

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Coleman, J.S. 1956. Purification of Gram Amounts of Americium, LA-1975, Los Alamos 

Scientific Laboratory. Los Alamos, New Mexico, May 21, 1956. 

Hacker, B. 1987. The Dragon’s Tail: Radiation Safety in the Manhattan Project, 1942-1946. 

University of California Press, p. 69. 

DOE (Department of Energy) 1990. DOE Order 5484.1, Environmental Protection, Safety and 

Health Protection Information Reporting Requirements. October 17, 1990 

DOE (Department of Energy) 1991. Tiger Team Assessment of the Los Alamos National 

Laboratory, DOE/EH-0204. U.S. DOE Assistant Secretary of Environment, Safety, and Health. 

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Ijaz T., Adler, T. C., 2004. Technical Basis Document for the Y-12 National Security Complex – 

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Inkret, W.C., M.E. Schillaci, Y.S. Cheng, M. Boyce, D.W. Efurd, T. Little, G. Miller, J.A. 

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Aerosols, LA-UR-99-6221, Los Alamos National Laboratory, Los Alamos, New Mexico. 
 

 

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Johnson, P.G. 2004. Technical Basis Document for the Los Alamos National Laboratory – 

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Kathren, R.L., 2003. Technical Information Bulletin: Dose Reconstruction from Occupational 

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Kathren, R L. and V.E. Shockley 2005. Technical Information Bulletin: Dose Reconstruction 

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LAP (Los Alamos Project) 1944b. Progress Report Number Twenty-Four of the Experimental 

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at the Los Alamos National Laboratory, LAHDRA 136, Los Alamos, New Mexico. 

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LASL (Los Alamos Scientific Laboratory) 1951. H-Division Progress Report. 

October 20–November 20, 1951, Los Alamos, New Mexico. 
 

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LASL (Los Alamos Scientific Laboratory) 1962. Primary Radiological Safety Guide and 

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Diagnostic X-ray Unit, Los Alamos, New Mexico. Mary 8, 1972. 

LASL (Los Alamos Scientific Laboratory) 1976. Standard Operating Procedure for the H-2 

Diagnostic X-ray Unit, SM-409, Los Alamos, New Mexico. Mary 8, 1972. 

Leonowich, J.A., D. Bihl, J.J. Fix, D. Shipler, B. Napier, M. Rolfes, and T. Taulbee 2005. 

Technical Basis Document for Atomic Energy Operations at the Iowa Army Ammunition Plant 

(IAAP), ORAUT-TKBS-0018, Oak Ridge Associated Universities, Oak Ridge, Tennessee. 

March 14, 2005. 

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Inhalation Exposures to PuO2, RFP-1123, presented at the 13th Annual Meeting of the Health 

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Particulates, Fusion Technology, Vol. 28. October 1995. 

McDowell-Boyer, L. and C. Little 2004. Technical Basis Document for the Rocky Flats Plant – 

Occupational Environmental Dose, ORAUT-TKBS-0011-4, Oak Ridge Associated Universities, 

Oak Ridge, Tennessee. June 19, 2004. 

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333. March 1991. 

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External Dose Assignment, ORAUT-OTIB-0020, Rev. 00, Oak Ridge Associated Universities, 

Oak Ridge Tennessee. December 29, 2004. 

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Assignment of Shallow Dose, ORAUT-OTIB-0017, Rev. 00, Oak Ridge Associated Universities, 

Oak Ridge Tennessee. January 19, 2005. 

Meyer, D.D. 1958a. Group H-1 Monitoring, LANL H-Division Progress Report December 20, 

1957 – January 20, 1958, page 2. 
 

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Meyer, D.D. 1958b. Group H-1, Monitoring – Special Monitoring, LANL H-Div Progress 

Report, August 20–September 20, 1958. 

Meyer, H.E. 1994. History of Personnel External Dosimetry Program at the Dayton Project and 

Mound Laboratory 1946–1993, Mound Laboratory. Miamisburg, Ohio. 

Millard, J. 2004. Technical Basis Document for the Mound Site –Occupational Internal 

Dosimetry, ORAUT-TKBS-0016-5, Oak Ridge Associated Universities, Oak Ridge, Tennessee. 

September 9, 2004. 

Morgan, A.N., K.W.R. Johnson and J.A. Leary 1962. Preparation of Neptunium-237 Metal, 

LAMS-2756, Los Alamos Scientific Laboratory, Los Alamos, New Mexico. September 5, 1962. 

Murray, W.E. 2003. Technical Basis Document for the Y-12 National Security Complex – 

Occupational Medical Dose, ORAUT-TKBS-0014-3, Rev. 00, Oak Ridge Associated 

Universities, Oak Ridge, Tennessee. December 15, 2003. 

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Population in the United States and Canada from Natural Background Radiation, NCRP 

Report 94, Bethesda, Maryland. 

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Electron Beam, and Gamma-Ray Protection for Energies Up to 50 MeV (Equipment Design, 

Performance, and Use), Report No. 102, NCRP, Bethesda, Maryland. 

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of the National Citizen’s Hearings for Radiation Victims. April 10-14, 1980, pg. 19. 

NIOSH (National Institutes for Occupational Safety and Health), 2002a, External Dose 

Reconstruction Implementation Guidelines, OCAS-IG-001, Revision 1, Office of Compensation 

and Analysis Support, Cincinnati, Ohio, August 2002. 

NIOSH (National Institutes for Occupational Safety and Health), 2002b, Internal Dose 

Reconstruction Implementation Guidelines, OCAS-IG-002, Revision 0, Office of Compensation 

and Analysis Support, Cincinnati, Ohio, August 2002. 

OCAS (Office of Compensation of Analysis and Support) 2003. Tritium Calculations with 

IMBA, OCAS-TIB-002, Rev. 00, National Institute for Occupational Safety and Health, Centers 

for Disease Control and Prevention, U.S. Department of Health and Human Services, 

Washington, DC. April 22, 2003. 

Peterson, E.J. 2002. Isotope Production at the Los Alamos National Laboratory, LA-UR-02­

2302, Los Alamos National Laboratory, Los Alamos, New Mexico. 
 

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Rising, F.L., and J.K. Soldat 1959, Radiation Exposures During Diagnostic Radiographic 

Examinations at Kadlec Methodist Hospital, letter to Dr. W. D. Wood. April 30, 1959. 

Rogers, M.A. 1977. History and Environmental Setting of LASL Near-Surface Land Disposal 

Facilities for Radioactive Wastes (Areas A, B, C, D, E, F, G, and T), LA-6848-MS, Vol. I, June 

1977. (Numerous radioactive waste site fires are described in this report, which are referenced to 

official documents). 

Rohrig, N. 2004. Technical Basis Document for the Idaho National Engineering and 

Environmental Laboratory (INEEL) – Occupational Medical Dose, ORAUT-TKBS-0007-3, 

Rev. 00, PC-1, Oak Ridge Associated Universities, Oak Ridge, Tennessee. May 28, 2004. 

Rollins, G. (2004). Technical Information Bulletin, Maximum Internal Dose Estimates for 

Certain DOE Complex Claims, ORAUT-OTIB-0002, Oak Ridge Associated Universities. Oak 

Ridge, Tennessee. 

Savignac, N. 2003. Technical Basis Document for the Hanford Site – Occupational 

Environmental Dose, ORAUT-TKBS-0006-4, Rev. 00, Oak Ridge Associated Universities, Oak 

Ridge, Tennessee. October 15, 2003. 

SC&A 2004. SC&A Standard Operating Procedure for Performing Site Profile Reviews, Rev. 0. 

March 18, 2004. 

SC&A 2005a. Review of the NIOSH Site Profile for the Nevada Test Site, SCA-TR-TASK1­

0006, S. Cohen and Associates. McLean, Virginia. December 13, 2005. 

SC&A, 2005b, Review of the NIOSH Site Profile for Rocky Flats Plant, SCA-TR-Task1-0008, 

S. Cohen and Associates. McLean, Virginia. December 8, 2005. 

Scalsky, E. D. 2003. Technical Basis Document for the Hanford Site – Occupational Medical 

Dose, ORAUT-TKBS-0006-3, Rev. 00, Oak Ridge Associated Universities, Oak Ridge, 

Tennessee. September 16, 2003. 

Scalsky, E.D. 2005. Savannah River Site, ORAUT-TKBS-0003, Revision 3, Oak Ridge 

Associated Universities, Oak Ridge, Tennessee. April 5, 2005. 

Schulte, H.F. (1966). Memorandum from H.F. Schulte to Dr. T.L. Shipman dated June 28, 1966, 

Bioassay and Environmental Sample Analyses, Los Alamos National Laboratory, Los Alamos, 

New Mexico. 

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Shipman, T. 1952. Special Problems, LANL H-Division Progress Report. January 20, 1952– 

February 20, 1952, pg. 2. 

Shipman, T., 1955. LANL H-Division Progress Report 7-20 to 8-20, 1955, pg. 5. 
 

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Shipman, T.L. 1962. H-Division Monthly Report, Los Alamos Scientific Laboratory. Los 

Alamos, New Mexico. 

Shockley, V.E. and R.L. Kathren 2005. Hanford Site – Occupational Medical Dose, ORAUTTKBS-0006-3, Oak Ridge Associated Universities, Oak Ridge, Tennessee. April 11, 2005. 

Silver, K. 2005. Review and Critique of the Draft NIOSH Site Profile Document for Los Alamos 

National Laboratory, East Tennessee State University, Johnson City, Tennessee. September 19, 

2005. 

Silver, K. 2006. Letter to Joe Fitzgerald, Saliant Inc. March 30, 2006. 

Snapp, L.M. 2003. Practical Use of Personal Air Sampling (PAS) Data in the Internal 

Dosimetry Program at the Y-12 National Security Complex, RCO-2003-004, Oak Ridge, 

Tennessee. 

Steele, C. and J.E. O’Neil 1998. CMR Basis for Interim Operations, Los Alamos National 

Laboratory, Los Alamos, New Mexico. August 27, 1998. 

Stone, Robert S. 1948. Health Protection Activities of the Manhattan Project, Proceedings of the 

American Philosophy Society, Vol. 90, No. 1. January 1948, pp. 11–19. 

Voelz, B.L., J.H. Stebbings, L.H. Hempelmann, D.A. Haxton and D.A. York 1978. Studies on 

Persons Exposed to Plutonium, International Symposium on the Late Biological Effects of 

Ionizing Radiation, Vienna, Austria. March 12–17, 1978. 

Westbrook, J.L. 2005. Basis for Development of an Exposure Matrix for the Mallinckrodt 

Chemical Company St. Louis Downtown Site and the St. Louis Airport Site, St Louis, Missouri, 

Period of Operation, 1942–1958, ORAUT-TKBS-0005, Rev. 01, Oak Ridge Associated 

Universities, Oak Ridge, Tennessee. March 10, 1005. 

Widner, T.E. 2005. Technical Basis Document for the Los Alamos National Laboratory – 

Occupational External Dose, ORAUT-TKBS-0010-6, Rev. 00, Oak Ridge Associated 

Universities, Oak Ridge, Tennessee. May 10, 2005. 

Wing, S. and D. Richardson 2004. Occupational Health Studies at Los Alamos National 

Laboratory, New Mexico’s Right to Know: The Impacts of LANL Operations on Public Health 

and the Environment, Concerned Citizens for Nuclear Safety. 
 

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ATTACHMENT 1: NIOSH TECHNICAL DOCUMENTS CONSIDERED 

DURING THE REVIEW 

Technical Basis Documents 

ORAUT-TKBS-0010-1. Technical Basis Document for Los Alamos National Laboratory – 

Introduction Rev. 00 (Buddenbaum 2005). 

ORAUT-TKBS-0010-2. Technical Basis Document for Los Alamos National Laboratory – Site 

Description Rev. 00 (Buddenbaum 2004). 

ORAUT-TKBS-0010-3. Technical Basis Document for Los Alamos National Laboratory – 

Occupational Medical Dose Rev. 00 (Johnson 2004). 

ORAUT-TKBS-0010-4. Technical Basis Document for Los Alamos National Laboratory – 

Occupational Environmental Dose Rev. 00 (Cehn and McDowell-Boyer 2004). 

ORAUT-TKBS-0010-5. Technical Basis Document for Los Alamos National Laboratory – 

Occupational Internal Dose Rev. 00 (Argall 2004). 

ORAUT-TKBS-0010-6. Technical Basis Document for Los Alamos National Laboratory – 

Occupational External Dose Rev. 00 (Widner 2005). 

Technical Support Documents 

ORAUT-OTIB-0002, Rev. 01 PC-2, (2004), Technical Information Bulletin, Maximum Internal 

Dose Estimates for Certain DOE Complex Claims, Oak Ridge Associated Universities, Oak 

Ridge, Tennessee, May 7, 2004 (Rollins 2004). 

ORAUT-OTIB-0006 2005. Technical Information Bulletin: Dose Reconstruction from 

Occupationally Related Diagnostic X-ray Procedures, Rev. 03, Oak Ridge Associated 

Universities, Oak Ridge, Tennessee. December 21, 2005. (Kathren and Shockley 2005). 

ORAUT-OTIB-0018, Rev. 01, 2005. Internal Dose Overestimates for Facilities with Air 

Sampling Programs, Oak Ridge Associated Universities, Oak Ridge, Tennessee, August 9, 2005, 

(Brackett and Bihl 2005). 

OCAS (Office of Compensation of Analysis and Support) 2003. Tritium Calculations with 

IMBA, OCAS-TIB-002, Rev 00, National Institute for Occupational Safety and Health, Centers 

for Disease Control and Prevention, U.S. Department of Health and Human Services, 

Washington, DC, April 22, 2003. 
 

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ATTACHMENT 2: SITE EXPERT INTERVIEW SUMMARY 

Two sets of site expert interviews were conducted with 47 former and current Los Alamos 

National Laboratory (LANL) employees, Department of Energy (DOE) – Albuquerque oversight 

personnel, and individuals conducting historical research on LANL. Years represented by those 

interviewed range from 1945–2006. The interviews were conducted by Joseph Fitzgerald and 

Kathryn Robertson-DeMers, “Q”-cleared members of the SC&A LANL review team. The 

purpose of these interviews was to receive first-hand accounts of past radiological control and 

personnel monitoring practices at LANL, to better understand how operations were conducted, 

and to obtain further understanding of LANL employee participation in nuclear testing. The 

initial set of interviews was conducted from November 28–December 2, 2005. After review of 

the documents retrieved and the first set of site expert interviews, it was decided that a second 

visit was required. The second visit was conducted April 25–29, 2006, and included classified 

interviews, further document review, and an extensive tour of LANL from the Security Force. 

Security was chosen due to the extensive input they provided in the November 2005 interviews. 

Interviewees were selected to represent a reasonable cross-section of production areas and job 

categories. Interviewees were originally obtained through LANL, the National Institute for 

Occupational Safety and Health (NIOSH) worker outreach meeting minutes, union 

organizations, and other former health physics staff. 

Workers were briefed on the purpose of the interviews and the LANL Site Profile. They were 

asked to provide their names in case there were follow-up questions. Participants were reminded 

that they would be provided the opportunity to review the interview summaries prior to inclusion 

into this report. Not all interview participants provided comments to SC&A. Interviewees from 

unclassified interviews were told that there were aspects of operations that were classified and 

that this information could not be divulged unless proper arrangements were made. To ensure 

classified information had not been included in the interview notes, the notes were reviewed by a 

classification officer prior to release. 

Current and former LANL employees interviewed worked throughout the LANL site. Some of 

the primary buildings associated with their work included the following: 

• Beryllium Technology Facility 

• Chemical and Metallurgy Research (CMR) (TA-3-29 or SM-29) 

• TA-3-28, Wing 9, TA-3-164, Bldg.46-200, TA-3-141 

• Plutonium Chemistry and Metallurgy (TA-1, D-Building) 

• DP East 

• Dual Axis Radiographic Hydrodynamics Test (DARHT) Facility (firing site) 

• Dynamic Experiment (DX) 

• Plutonium Facility (DP West, TA-21) 

• Health Research Laboratory (HRL, TA-43) 

• Los Alamos Meson Physics Facility (LAMPF, TA-53) 

• Los Alamos Neutron Science Center (LANSCE, TA-53) 

• Mesa Facility 

• Omega East Re actor 

• Van de Graaff Accelerator (TA-3-16) 
 

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• Omega West Site (TA-2) 

• TA-3 

• TA-15 (firing site) 

• TA-16-205 (WETF) 

• Critical Test Facility (TA-18) 

• Wet Chemistry (TA-21-3) 

• High Pressure Tritium Lab oratory (TA-33) 

• Kappa Site (TA-36) (firing site) 

• W-Site Tunnel (TA-41) 

• WA Site (TA-46) 

• Radiochemistry Site (TA-48) 

• TA-48-RC1 

• TA-48-5 

• Waste Management Site (TA-50) 

• Waste Storage Facility (TA-54) 

• Plutonium Facility (TA-55) (PF3, PF4, etc.) 

• TA-59-1 

• Firing Sites 

• GT Site 

Support personnel (e.g., maintenance, security, etc.) had access to all areas of the laboratory. 

Some individuals interviewed participated in weapons testing at Amchitka, Nevada Test Site 

(NTS), Trinity, and in the Pacific. 

The job categories represented incl uded the following: 

• Accelerator Scientist 

• Accelerator Technician 

• Chemist 

• Chemical Technician 

• Chemistry Team Lead 

• Construction Pipefitter 

• Construction Utility Wo rker 

• Custodians 

• DOE Radiological Control A uditor 

• DOE Radiation Safety Officer 

• Electrical Di scharge Machinist 

• Electrician 

• Environmental Dose Assessmen t 

• Group Leader, Health and Safety Division 

• Health Physicist 

• Machinist 

• Mechanical Technician 

• Medical X-ray Technician 

• Meteorology and Air Quality 

• Occupational Nurse 
 

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• Painter 

• Radiological Control Technici an/Radiation Monitor 

• Radiological Control Technician Supervisors 

• Reactor Operator 

• Reactor Technician 

• Section Leader 

• Security Guard 

• Security Captain 

The information the wo rkers provided to SC&A has been invaluable in providing a working 

knowledge of the various site operations, the safety program, and the LANL involvement in 

weapons and weapons component testing. All interviews have been compiled and summarized 

below. This is not a verbatim discussion, but is a summary of information from multiple 

interviews with many individuals. The information provided by the interviewees was based 

entirely on their personal experience. It is recognized that site expert and former LANL 

workers’ recollections and statements may need to be further substantiated. However, they stand 

as critical operational feedback and reality reference checks. These interview summaries are 

provided in that context. LANL site expert input is similarly reflected in our evaluation. Wit h 

the preceding qualifications in mind, this summary has contributed to our findings and 

observations. 

Security 

Starting in 1947, LANL security worked for the Department of Energy. In 1981, Mason and 

Hanger to ok control of security at the lab. Since April 1992, the Security subcontractor at LANL 

has been Protection Technology Los Alamos (PTLA). 

Security existed at LANL to take care of Category 1 and Category 2 Special Nuclear Material 

(SNM), and provide safekeeping of other nuclear devices and explosives. Since LANL was 

handling plutonium, security in the plutonium areas wa s tight. Security checkpoints were 

established throughout the laboratory. Security officers provide a safe work environment for 

personnel entering and exiting LANL, and safety for personnel working on special projects. 

When the Security Guards were under the jurisdiction of the Atomic Energy Commission (AE C) 

and its predecessors, they had full access to all areas onsite. Years ago, this included entry int o 

storage vaults. Security performed patrols of the buildings and areas on foot, in vehicles, or o n 

horseback. Building patrols required guards to check the outside of the building and perform 

internal walk through of areas including radiological areas. They verified that vaults were 

sealed, and in some cases were required to inventory seals, packages, and items in the vault. 

Rotations at a particular post were repeated periodically (i.e., every 30, 45, or 60 minutes). 

These types of walking tours were common in areas with plutonium, such as TA-21 and TA-55 , 

as well as other facilities, such as Machine Shops and SNM storage areas. Guards had full 

access to all areas of these buildings. Many times officers were stationed in areas where nucle ar 

weapons and/or components were out in the open. Security personnel were required to 

accompany fire inspectors into production areas for fire checks of glove boxes. They entered the 

explosives areas, the TA-41 tunnel where nuclear material was stored, the Omega Reactor Site, 
 

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and other site locations where radioactive material was handled or stored. In more recen t years, 

special access is required for some areas, such as vaults, so guards are stationed in corridors 

when guarding material. 

Security officers responded to alarms throughout the LANL facility, which included roadbloc ks, 

incidents, and accidents, a nd were often the first to respond to these situations. Special Nuclear 

Material Monitors were used to pick up the gamma and neutron signatures of SNM. These 

monitors had an alarm capacity and would frequently alarm as material passed by. When these 

units alarmed, patrol was required to enter the area and determine why the alarm was sounding. 

For example, many times alarms took them into TA-3, Building 29, and the Wing 2 basement 

when the SNM monitor alarm was sounding. In some cases, when responding to alarms at 

facilities in TA-2, TA-16, TA-41, TA-18, and DP-West, they actually had to pass through 

laboratories to get to the alarm or vault, or be stationed inside the vaults until the incident was 

resolved. As the eyes and ears of the laboratory on off-hours, and they were often the 

individuals who identified spills or unusual conditions. 

Environmental exposures were also a possibility. Security staff towers were next to the Kiva’s, 

and they were occasionally not relocated when the Kiva’s were running. Armored vehicles were 

used near the Kiva-3 critical assemblies. Security was not always alerted when the assembly 

approached criticality. This created a potential exposure. Security would drive around the 

PHERMEX area where they conducted explosion tests. There were security checks and 

patrolling of the area including entry of the building. Initially this area was not posted; howev er, 

later, guards found out that roads were being closed and roped off. There were then signs posted 

saying “Grave Danger.” The guard post for TA-2 was adjacent to the fuel storage area an d 

across a road from the reactor. Security exercises were conducted in the TA-2 area; however, 

they were later told not to do exercises there. 

Another responsibility of Security was to guard SNM. For example, Security was required to 

guard TA-2 reactor fuel rods when handled in Chemical and Metallurgy Research, Wing 9. 

They were within hands-reach of the storage containers. Security officers usually worked 17–18 

hour days when assigned to work in this area. Special Security was responsible for escorting 

radioactive material for scientists. Scientists work with SNM 6–8 hours per day, but Security 

Officers provide security for this item 17–18 hours a day, plus they were there the following day. 

They were in the immediate work area throughout the week. 

Safe Security vehicles were used to transport material onsite. Transport to TA-8 for quality 

assurance x-ray checks was common. The nuclear material is placed in a container with a seal. 

All personnel exited the room while the x-ray was shot. Security had to return to the room, 

verify that the material was replaced, and replace the security seal on the container. 

Security was responsible for inventorying material transported offsite, such as to the Nevada Test 

Site. This activity resulted in higher dosimeter readings than usual. They also worked and 

participated in the exercises involving detonation of nuclear weapons, with a potential for 

exposure. 
 

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Security staff were not allowed to leave their post during some assignments (e.g., the tunne l 

post), and meals were eaten at the post, which may have been in areas with chemical and/or 

radiological material. Security was also not allowed to co-mingle with LANL personnel, such as 

in their cafeterias. Guards were not allowed to leave their post. Often times, LANL employe es 

were made to evacuate a certain area because an alarm went off. However, the security offic er 

was required to stay with the item. Protective suits and/or respirators were not provided officers 

during these situations. Even after an area was cleared and workers returned to work, guards 

were not told of the potential exposure. According to interviewees, guards were also not told 

about the chemical hazards they encountered unless they had a “need-to-know.” This had been 

an ongoing hazard to PTLA employees. 

Despite touring radiological areas, the typical measured dose by the dosimeter was zero. This 

did not make sense to those who spent con siderable time in these areas. Despite obvious 

exposures, and guards sometimes setting off alarms on the SNM monitors when exiting a work 

area, dosimeters still gave a zero reading. Security officers were not routinely monitored throug h 

bioassay testing. 

On specific tours, guards had to punch into Detex clocks. Security logs were maintained; 

however, there are likely classification issues with accessing these. Some, but not all, facilities 

maintained hardcopy or electronic entry logs to keep track of individuals entering a particular 

facility. Zone Activity Reports also tied an individual to an area at a particular time. This 

information, coupled with survey data, could serve as a method for tracking entries into 

radiological areas. 

According to current and former security personnel, Mason and Hanger apparently imple mented 

a point system and placed everyone on a minus 35 points. According to one interviewee, in 

order to earn points, employees were encouraged to “snitch” on one another. Mason and Hanger 

apparently maintained a secretive atmosphere. As noted by one former guard, individuals didn’t 

complain or they were “in trouble.” Employees of Mason and Hanger worked long hours as the 

contractor tried to minimize the total number of employees. During this time period, former 

security personnel indicated they worked 40–80 hours per week; sometimes 16–18 hours at the 

same post. In 1993, there were contract changes that restricted security personnel to 72 hours per 

week. Overtime typically was directed or involuntary. The current Collective Bargaining 

Agreement allows Security personnel to work up to 96 hours per week. Roughly 75% of the 

workday was spent in radiological areas. In March 1989, there was a strike that lasted 69 days; 

during that timeframe, the contractor (Mason and Hanger) was reportedly involved in fourte en 

unfair labor practices, many of which implicated forced overtime as an issue. 

Accelerators 

LANL began accelerator operations in the 1940s with a long tank Van de Graaff Accelerator, a 

short tank Van de Graaff Accelerator, a Cyclotron, and a Cockcroft-Walton Accelerator. 

Accelerators at LANL were used for atomic and nuclear research, and to produce a wide variety 

of radionuclides. There were likely activation products in the work environment. Some 

radionuclides were produced for sale while others remained onsite. There has not been a good 

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The Van De Graaff accelerator had peak energy of 18 Mev. Hydrogen, deuterium, tritium , and 

helium were the primary particles being accelerated toward the target. It had a sputter source so 

it was capable of accelerating heavier (higher-Z) elements. The facility had multiple interlo ck 

systems. The particular interlocks activated are dependent on the energy used and the target. 

Tritium was a significant source of radiation at this facility. Flow-through ionization chambers 

(e.g., Johnston 110, Johnston 111, Operhoff 394) were used to monitor airborne levels. More 

recently, bubble suits were used for entry into areas with high levels of tritium. It could produc e 

neutron energies that even the Los Alamos Meson Physics Facility (LAMPF) facility was not 

able to produce. 

The Isotope Production Facility used “naked” (H+) beams from LAMPF and had hot cells for 

handling target change-out. The beamline maintenance and target areas were the source of mo st 

exposure at LAMPF. There was some neutron exposure at the LAMPF, but only during 

operation. Areas A and B had airborne environmental emission problems due to releases of 

short-lived radioactive gases, e.g., tritium and iodine. Penetrating radiation was much less of a 

problem. 

The Los Alamos Neutron Science Center (LANSCE) is a proton accelerator with energies up to 

800 MeV. LANSCE accelerated H+, H-, and polarized domes. There was some concern related 

to exposure from C-11, O-16, N-15, and Ar-41 when entry was not adequately delayed for 

decay. The LANSCE facility produced a neutron hazard with a wide energy range of neutrons. 

The accelerator produced a number of short-lived radionuclides during its various operations. 

Most doses came from tritium, iodine, and noble gases. In the modern era, workers wear 

“bubble suits” in potentially high tritium atmospheres, and use gloves otherwise. Thorium-230 

and Th-232 were used as targets at LANSCE. 

Ground Test Accelerator at TA-53 involved “neutral beam” experiments in support of the 

strategic defense initiative (“Star Wars”). The Low Energy Demonstration Accelerator used 

proton beam at the 70–90 MeV range in late 199 0s (not particularly high energy). The Ground 

Test Accelerator and the Low Energy Demonstration Accelerator have been decommissioned. 

The New “Lujan Center” (aka LANSCE) limits operator exposure with heavily shielded 

experimental halls; typical annual radiation in 5–15 mrem range. However, resident researchers 

in this facility may have as much as 300–400 mrem in neutron dose due to proximity to beam 

operation. This is probably the most potentially significant exposure issue because of the higher 

residence time of experimenters at LANSCE (>18 hours/days, sometimes) and the presen ce of a 

thermal neutron field. Changing the accelerator target boxes, often kilocurie targets, would give 

a typical maintenance worker doing this task 300–400 mrem a year, with some as a high range of 

600–900 mrem/year. To minimize such exposures, remote handling of sources was used. High 

gamma exposures are also seen in TA-48 where the targets are handled and radionuclides 

separated. 

Mechanical Technicians were responsible for performing maintenance on the accelerator 

(maintenance days) from one end to the other. Maintenance days would be set up to work on 

parts of the accelerator. Each section had its own maintenance group which performed duties on 

maintenance days. Activities included maintenance on ion pumps, isolation valves, diagnostic 
 

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equipment, etc. In order to change isolation valves, repair or replace diagnostic equipmen t, and 

repair or replace ion pumps, the technicians would have to straddle the magnets. They also did 

vacuum work and welded beam pipes. Electricians were responsible for the electrical 

components at the accelerator. A lot of the maintenance work was done in the 201 Area/ 

203 Area in the tank sections. While evacuating the tank sections, working in experimental 

areas, or performing vacuum leak checking at the vacuum lab, the mechanical pumps and blowe r 

packages emitted oil vapor/mists and exhausted smoke into the areas. Other responsibi lities 

included rebuilding of vacuum ion pumps, cryogenic pumps, mechanical pumps, isolation 

valves, turbomolecular pumps, and repairing of diagnostic equipment. They were also involved 

with fabrication of beam piping, silver soldering of let-up valves, etc. During the down time of 

any one of the domes, technicians would evacuate the dome system (bring it to atmosphere) f or 

replacement of ion pumps and instrumentation. Periodically the maintenance personnel wo uld 

have to enter the domes to remove the source, which generates the beam. Radioactive material 

would leak on top of the turbomolecular pumps. 

Special entries were made to repair accelerator functional critical equipment. For corrective 

maintenance, entry into the accelerator area occurred shortly after shutdown, not allowing 

sufficient time for short-lived radionuclides to deca y completely. The scientists were not tolerant 

of having maintenance hold up their experiments, so there was pressure to get the accelerator 

back online as soon as possible. 

Chemistry 

The Chemistry Division, also ref erred to as the C Division, is composed of several departments. 

Analytical Chemistry is located at the Chemical and Metallurgical Research (CMR) facility. 

Chemists and Meta llurgists at CMR worked with plutonium, uranium (including U-233), 

neptunium, americium, radioactive gases, thorium isotopes and their daughters, and curium. The 

Chemistry Division worked with pure transuranics and performed analysis (e.g., inorganic trace 

analysis) on waste forms. Work was done in an open front hood or glove box. The Chemical 

Division provided analytical support to operations from all over the laboratory. There is 

currently a research group evaluating the behavior of plutonium in aqueous system in the 

environment. The Isotope and Nuclear Chemistry group is responsible for analytical support to 

the Medical Radioisotopes Group. TA-48 provided chemical separations support to the weapo ns 

testing group. Chemists unexpectedly identified Cm-244 during a contamination spill in C MR 

about 6–8 years ago. The material was particularly “flighty.” 

There are multiple operations in CMR that produce an external exposure hazard. Industrial x-ray 

units were scattered throughout the laboratory and included x-ray diffraction units, x-ray 

photoelectron spectroscopy units, and x-ray fluorescence units. Control on radiation generating 

units was not as stringent until about the 1980s. Units could be bought without the knowledge of 

Radiological Control. A majority of the x-ray diffraction units were closed beam; however, there 

were some open beam units. The level of exposure to chemists and technicians was depen dent 

on where they were assigned at LANL and their particular responsibilities. 

Chemists at the CMR lab were involved in a number of operations. More senior level chemists 

were responsible for all activities in the lab(s) under their jurisdiction. They had to respond to 
 

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any incidents or unusual events that occurred in their laboratories. The Chemistry staff 

performed manual as well as remote work. There were hot cells available for high potential 

exposure work. 

Other Operations 

The Low Power, High Power, and Super Power “water boiler” reactors were built in 1943 at the 

Omega Site to co nduct critical mass calculations, measure fission cross-sections, and conduct 

Neutron Radiography. A collimated beam was brought out of the water boiler to the object 

being radiographed. As a result of the radiation hazard, the area was roped off. Other reactors 

were built for reactor testing and experimentation. The Omega West Reactor had various 

neutron beam ports for experimentation. Ultra-High Temperature Reactor Experiment was a 

small high-temperature, graphite-moderated, gas-cooled reactor (8 mW) built as a pilot reactor in 

the early 1970s that was dismantled once design objectives were achieved. Los Alamos Molten 

Plutonium Reactor Experiment was a molten plutonium reactor. The Omega West area posed a 

major radiation exposure hazard compared to other areas onsite. The highest doses occurre d 

near the deionizer where dose rates could be several Roentgen per hour above the lead shield. 

The first critical assemblies were manipulated by hand until 1946. The Dragon Machine was the 

predecessor to the Super Prompt Critical or Burst Reactors (Godiva). The Masheba Device used 

low enriched uranyl fluoride as fuel. There was no shielding, so it had to be operated at night . 

Its operation required that roads be closed down. The Pajarito Site (TA-18) was developed to 

remotely complete critical and subcritical experiments. There were upwards of 40 machines 

used to study the effect of nuclear chain reactors. Some of the machines were operated outdoors 

which required that operations be conducted at night when most of the laboratory staff was gone. 

The road was closed due to the potential for exceeding offsite limits. Offsite exposures were 

monitored by placing dosimeters at the highway during operation of the experiments. Both 

pulsed and steady-state exposure was possible with more exposure occurring in the steady stat e 

capacity. The experiments were run from a control room with the critical assembly buildings 

located a distance away. This facility utilized real-time neutron field monitoring. Entry into the 

Criticality Assembly buildings occurred periodically for maintenance. 

TA-54 housed the solid waste facilities while TA-50 housed liquid waste facilities. The 

radiological conditions in TA-50 were better than that in TA-54. Various maintenance personn el 

have supported these areas (e.g., exhaust duct work, D&D, etc.) Waste drums were stored in 

many areas at the site. Under some conditions the waste drums were lea king. Approximately 35 

truckloads of waste were being accumulated and stored in drums in the basement of the CMR 

Building for a period of time. This waste was relocated to another location about the time the 

Tiger Team came to LANL. There is no record of how waste was disposed of in 1945. Through 

time, the methods have continually improved. 

The TA-21 Area (also known as the Old DP Site) was decommissioned in the late 1990s. During 

D&D, significant contamination was found at DP West. The area was painted over to try to 

control the contamination; however, they eventually had to pour concrete to control 

contamination. Initially, construction crafts were involved in disconnected pipes and utilities. 

After this, there was a dedicated crew responsible for the actual decommissioning work. 
 

 

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Hydrodynamic testing or Explosives Testing occurred in a number of the technical areas at 

LANL (e.g., S-site, TA-8, TA-9, TA-15, TA-16, and TA-33). 

Maintenance 

The Maintenance Division was segregated into facility-specific maintenance crews, Construction 

Maintenance, and a general maintenance pool. Facilities such as TA-55 and LANSCE had i ts 

own set of maintenance personnel. The Construction Maintena nce population was generally 

stable at LANL. They were responsible for new construction, remodeling, and some general 

maintenance. They were deployed to any location onsite, and were considered as a separate 

group from the standard maintenance crews. Construction Maintenance was typically provided 

by a subcontractor. The Hill was segregated into a number of zones that included multiple 

facilities. The general maintenance pool was assigned to a particular zone on the Hill. TA-3-38 

and TA-3-39 house the Central Crafts and Central Shops, respectively. 

Each craft had specific responsibilities: 

• 	 Pipefitters were involved in activities such as working on piping in glove boxes, cutt ing 

and replacing piping, and installing new piping. This work may or may not be done in a 

radiological area. 

• 	 Sheetmetal workers were respons ible for stack filter change outs among other things. 

• 	 Utility workers maintained, replaced, or installed plumbing, water lines, gas lines or any 

other utilities. 

• 	 Electricians maintained, installed, disconnected, or removed electrical materials including 

during demolition. 

• 	 Painters were responsible for painting fixed contamination areas, offices, roads, building 

structures, or o bjects. Painters could be assigned to a “hot area” or a “cold area.” Those 

not exclusively assigned to a hot area entered radiological areas about 3–4 times per year. 

• 	 Laborers were responsible for doing cleanup after hydrodynamic testing among other 

duties. 

• 	 Some custodians were responsible for sweeping, mopping, cleaning bathrooms, trash 

removal, and vacuuming administrative offices. Other custodians were required to clean 

up machine shops by sweeping up metal chips and scrubbing floors. Specially trained 

janitors, under the direction of Radiation Monitors, were responsible for decontaminati on 

activitie s. 

Hig ri h- sk maintenance jobs included equipment and filter changes, duct work, cutting or tying

into nli es and drains, and other similar activities. There was a potential for unexpected 

contamination and radiation hazards during these operations, although personnel got better at 
 

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anticipating these hazards with experience. Maintenance crews were sometimes involved in 

demolition work, such as drilling walls, concreted, floors, etc. 

Machine shops were located throughout the site (e.g., TA-2, TA-3, TA-21, TA-41), although no t 

every shop onsite handled radioactive material. There were machine shops dedicated to the 

handling and machining of sensitive materials. Special Metal Machining included machining of

lead, Tuballoy, Oralloy, plutonium, beryllium, etc. The Central Shop contained numerous 

machines including lathes, presses, grinders, milling machines, open boring mills, and a number 

of other machines. Machinists were typically responsible for more than one machine. The 

Central Shop was responsible for Electrical Discharge Machining that involved machining hard 

metals submerged in oil to form material into patterns. This was referred to as machining by 

sparking. Machines were historically open to the air versus the contained machines of today. 

There were not ventilation hoods over the machines. The machine shops were very dusty w hile 

operations were ongoing, and it was not uncommon to find material shavings on the floor. 

Operations created smoke and vapors from the metals being machined. The engineering controls 

such as ventilation and containment of material have improved over time. The upkeep to the 

Central Shop has improved significantly over time to the point where the shop is clean and 

organized today. 

Maintenance jobs were documented on a ticket and/or in a work package. Prior to the 

implementation of RWPs, Crafts Work Permits were required for authorization to work in an 

area. The permit was filled out by the Crafts Supervisor and reviewed by a Radiation Monitor . 

It did not document radiological requirements for a particular job. Names were documented for 

particular jobs on “Special Air Test” forms and/or “Accident/Incident” report forms if an 

incident occurred. Those mobile workers were required to sign in on “visitor logs” when 

reporting for work at a particular facility. Currently, maintenance staff works under Int egrated 

Work Documents that include the Radiation Work Permits (RWPs) and other safety 

requirements. These are used to communicate the hazards associated with the job and the 

controls to be put in place to minimize exposure. They have been used at LANL for at least 15– 

20 years. All activities in TA-55 and CMR require RWPs. 

Weapons Testing Participation 

LANL supported weapons testing at the Trinity, Nevada Test Site, and the Pacific Proving 

Grounds (PPG). Site experts participated in the Trinity test (1945), Operation Plumbbob (1957), 

Operation Hardtack Phase II (Fall 1958), 56 Project at NTS (1955–1956), the San Clemente 

Island Test, Long Shot in Amchitka (1965), and other tests at the Nevada Test Site and in the 

Pacific. A contingent of employee s, including individuals from all over the LANL site, was sent 

to the test site for weapons testing. W-Division was responsible for weapons assembly and 

actually placing the unit in the ground. H-Division provided Radiological Control and Med ical 

Support during testing. During the time when security was overseen by DOE, some employees 

would travel to the Nevada Test Site for testing of LANL devices. Security officers 

accompanied weapons to the NTS. They provided security at the site, by “cleaning the area” 

which included securing the perimeter. Officers secured the nuclear weapons in vaults, in 

vehicles, and in tunnels. Each individual from LANL who participated in NTS testing opera tions 

received a Certificate of Participation. 
 

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For Pacific tests, at any one time there were greater than 50 laboratory employees on the island 

and at detonation about 25 laboratory employees were on ships and/or involved in rec overy. At 

the Mike Event (1952), there were six laboratory employees on the island in a bunker. During 

the heavy underground testing period, approximately 100 individuals were at the test site fo r an 

event. Individuals were rotated so the same 100 individuals were not at each test. 

The lab was also involved in the evaluation of radiation as a result of testing. RCTs were sent to 

perform surveys and monitor personnel readings following the blast. Surveys were conducted 

prior to allowing LANL staff in to recover the equipment. For this operation they wore 

coveralls, booties, and sometimes respirators. There were about 10 surveyors who participated 

in offsite testing. 

The Long Shot (1965) test on Amchitka Island was sponsored by the Department of Defense 

(Defense Atomic Support Agency) using a Los Alamos device and Los Alamos scientists and 

technical personnel. The LANL sponsored the Milrow shot (1969) at Amchitka. The Cannikan 

shot was sponsored by LLNL. Amchitka was selected as the high-yield test site. For Long Shot, 

support staff included both military and civilian personnel. There was no radioactive material on 

the island except ca libration sources prior to the weapon arrival. The military provided the 

health physics and security support for the tests. Two weeks prior to the arrival of weapons at 

the site, there was pre-detonation sampling. A Remote Area Monitoring System was put in pl ace 

to monitor the environment during and after the shots. Air sampling equipment was set up to 

monitor gamma radiation. Long Shot was an 80-kiloton shot approximately 2,300 ft 

underground. Long Shot was completed to provide seismic information from the detonation of 

weapons underground. Tritium was identified in the surface water about one year after the test. 

Milrow was a one-megaton shot approximately 4,000 ft underground. There was no drill-back 

attempted for Milrow, nor was there an atmospheric release to the environment. 

Test reactors were designed at LANL for application in the Nuclear Rocket Program and tested 

at NTS. There was a permanent party of 20–25 LANL employees supporting the Nuc lear Rocket 

Development Station at NTS. Tested under this program were Kiwi and Phoebus reactor 

designs. The fuel was fabricated and the initial critical experiments were completed at LANL. 

The ROVER reactors were constructed and underwent initial verification at LANL, they were 

taken apart and transported to NTS, and they were reassembled at the Nevada Te st Site (NTS). 

The Nuclear Rockets involved had power levels of 300, 1,500 and 4,000 megawatts. The “super 

kukla” reactor was operated in Test Cell C at NTS in 1965. When the reactor tests occurred, 

individuals were positioned upwind from ground zero. With these types of tests, iodine releases 

were expected so measurements were made. 

LANL and the military participated in the Enewetak Radiation Support Project. Laboratory 

employees were sent to Enewetak for six weeks at a time for a period of two years. There was 

measurable plutonium on the island. Plutonium bioassay was performed by the laboratory before 

and after deployment. 

Upon completion of the underground tests, a portion of what was left of the device was removed 

and monitored as it was brought to the surface. The laboratory was interested in retrieving the 

refractory material (e.g., glass at the bottom of the hole) for analysis back at the laboratory. 

“2R” Department of Transportation containers were used to transport samples from the core 
 

 

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extraction to TA-48 to the Radiochemistry Group. TA-48 handled and evaluated core samples 

returned from the test sites after weapons testing was completed. After the test was completed, 

the drill ridge and area at the test site were decontaminated and decommissioned. The hole 

created during the explosion was plugged with concrete. 

NTS provided dosimetry for LANL personnel participating in weapons testing and test shots at 

the NTS. Their LANL dosimeters were not to be worn at NTS. Those participating in testing 

were diligent about wearing their dosimeter. REECo was responsible for processing the 

dosimeter and providing the results back to LANL. LANL provided the dosimetry for the 

Pacific tests (i.e., Enewetak and Bikini). While retrieving radioactive samples during post-sh ot 

drilling, both REECo and LANL workers, who were hand ling tools or containers of radioactive 

material, wore assigned extremity dosimetry. The laboratory Health Physicist at the drill-back 

location determined who were issued these dosimeters. They were supplied and processed by 

REECo onsite, and the results were sent to LANL. NTS dosimetry results were added to the 

individual’s LANL occupational exposure record as they are reported to LANL. 

RCT were present on the drill rigs to check for elevated exposure rates. A series of air samples 

(filter/charcoal canisters) were taken and analyzed at the Nevada Test Site. Continuous Air 

Monitors (CAMs) with the capability of discriminating between xenon and iodine were operated 

during the drill backs. If there were elevated airborne levels, the CAM would alert personnel. 

Certain REECo employees were selected to submit a bioassay sample. This information was 

passed back to LANL individuals with a quick turnaround time so decisions could be made to 

sample or not sample LANL employees. The REECo lab would process initial bioassays and 

ship the data back to the laboratory. Iodine was the principal radionuclide potentially causing 

internal exposure. LANL personnel were periodically monitored for iodine uptake using gam ma 

spectroscopy. Data was considered qualitative and was not used for dose assessment. During 

this period of time the laboratory used bioassay (urine) samples to calculate the dose of record. 

The primary bioassay for LANL employees was the responsibility of the laboratory. Bioassay 

samples were taken after testing upon return to the laboratory. The type of sampling was based 

on the particular routine monitoring program (e.g., urinalysis once per year, in vivo count every 

three years after its implementation). Special bioassay sampling was conducted if there were 

problems with the drill-back. During Project 56 and Project 57, there was a considerable amou nt 

of plutonium bioassay sampling. 

Tritium Operations 

LANL has been involved in work with tritium since the 1940s. Some of the major tritium 

facilities formerly or currently at LANL include: 

• High Pressure Tritium Lab oratory (HPTL) 

• Tritium System Test Assembly (TSTA) Facility 

• Tritium Scienc e and Fabrication Facility (TSFF) 

• Weapons Engineering Tritium Facility (WETF). 

The HPTL (also called the Gas Handling Facility) was originally tasked with conducting 

research and development on tritium handling technology. This facility took over production 
 

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work f r a period of time, processing tritium ga o s an d repackaging tritium gas into small-volume 

high-p essure vessels. r In 1992, WETF began receiving t ritium and tritium contaminated gases, 

repack ging these gases, and preparing them fo a r shipmen t to other sites. TSFF provided a 

facility for Research and Development involving work w ith tritium gas and metal tritides. TSTA 

was involved in the use of tritium for development and demonstration of fusion fuel cycle 

technology. Other areas onsite which involved potential exposure to tritium include the 

following: 

• Van de Graaff Accelerators (TA-3-16) 

• Anchor Site East (TA-9) 

• LANSCE (TA-53) 

• TA-55 

• F Area Vaults 

• M Building 

• Y Building 

• Health Research Laboratory 

• Ion Beam Facility 

• Firing Experiments 

• Waste Handling 

Tritium handling opera tions, research and development activities, disassembly and retrofit of 

weapons, and tritium facility decontamination and decommissioning (D&D) activities have 

exposed workers to various forms of tritium. The primary forms of tritium at the laboratory 

include tritiated water (HTO) and trit ium gas (T2, HT). This constituted a majority of what was 

handled onsite. Special Metal Tritides (SMTs) and organically bound tritium (OBT) were found 

in spe ific areas onsite. c Metal tritides included hafnium tritide, lithium-tritium compounds, 

tritiated uranium, zirconi um tritide, and palladium tritide. The lighter metal tritides (e.g., lithium 

tritide) degrade to tritiated water which can be detected through bioassay. Heavier metal tritides 

behave similar to particulates. Tritides can be found in legacy materials. Fire or exposure of 

tritium gas will produce HTO. Other forms of tritium compounds, such as tritiated pump oil , 

rust, pump oil droplets, tritiated methane, and tritiated solvents, are formed during operations 

with HTO and HT and pose exposure hazards. For example, one worker came in contact with 

tritiated oil and received about one rem from the incident. 

Special Metal Tritides are difficult to detect with the traditional urine monitoring program. The 

insolubility of SMTs leads to a long residence time in the lung. It is easy to mistake intakes of 

special tritium compounds for chronic HTO exposures. As a result, LANL did routine tritium air 

monitoring and implemented enhanced engineering controls to keep particulates under control . 

A special monitoring program had to be established for this type of material. Tritium was 

handled in contained systems. Real-time tritium monitors are used in the tritium glove box area s 

and during recovery. The Bubble Suit is used when airborne tritium concentration cannot be 

controlled by other means. There are also integrated stack monitors to measure tritium 

exhausted out the stack. 

Tritium exposures in the accelerator areas were associated with tritium targets, as well as tritium 

contaminated liquids and surfaces (e.g., oils). Tritium bioassay was conducted on a routine 
 

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basis, after incidents, or as a post-job bioassay sample. The comprehensiveness of the tritiu m 

bioassay program for all workers is uncertain. Some site experts potentially exposed to tritium 

indicate they were monitored for tritium and others indicated they were not. There was genera lly 

no measurable dose from tritium for those monitored; although there were exceptions. 

Radiological Characterization 

The most radioactive areas at LANL include CMR, Wing-9, TA-21, and TA-55. External dose 

is particularly elevated with TA-55 vault and glove box work. LANL has worked with most 

elements on the periodic table from hydrogen up to curium. Some of the radionuclides 

encountered included plutonium, polonium, neptunium, curium, tritium, thorium (i.e., pellets and 

thorium powder), americium, fission products in the form of sources, radium and its dau ghters, 

medical isotopes (e.g., Mo-99, Ga), and noble gases. There are fission and activation products 

found in some areas of the site. 

Sigma Building processed natural and enriched uranium. Plutonium research at TA-1 started in 

1944. Prior to the closure of TA-1 plutonium operations were transferred to TA-21. 

TA-55 replaced TA-21 and continues operations today. There were trace amounts of Am-241 

found in TA-55. In TA-55-PF4 200-Wing, there is a Pu-238 Laboratory. The laboratory used to 

generate Pu-238 thermal generators for the space program, such as the “Cassini” project. Pu-238 

produces more neutrons and a “more active” gamma flux resulting in increased operator dose as 

compared to Pu-239. The Pu-238 is more flighty, making it more difficult to control. Chemical 

analysis for this operation was completed at CMR. 

Plutonium can be present as a powder oxide, metal oxide, and plutonium fluoride (fro m 

Plutonium Fluoride Reduction). The raw powder oxide can spread easily. After the oxide is 

cooked and formed into a capsule, a small amount of plutonium behaves like “fleas on a dog.” 

There were furnace operations at TA-55 to press and form Pu-238 and Pu-239 capsules at 

temperatures in excess of 600°C, creating the potential for high-fired oxides. 

The concentration of Pu-240 in plutonium is typically 6%. There are also trace amounts of 

Pu-238, Pu-241, and Pu-242. This material would be found in TA-55-PF4 and TA-21 in the 

past. With milligram quantities of plutonium, there is approximately 0.01% Am-241 on a mass 

basis. Ion Exchange was used to remove americium. The americium extracted from plutonium 

under normal operations is sent to the waste stream. Americium-241 will build up in the waste. 

Industrial x-ray units were used for quality control (e.g., weapons components , welds, etc.) and 

to record explosions. Both the PHERMEX Facility and the DARHT Facility used high energy 

flash x-ray machines to record explosions. The industrial x-ray units at PHERMEX emitted 

x-rays up to 25 MeV. Prior to shooting x-rays, the immediate area is roped off to prevent 

inadvertent entry. When the critical assemblies were pulsed, skyshine could be detected. As a 

result, if the dose rate at the public roadway exceeded 5 mrem for a typical operation, the road 

was closed to public access. 
 

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Radiological Controls 

The HSR-Division is divided into eight groups presently. These include Health Physics 

Operations (HSR-1), Occupational Medicine (HSR-2), Health Physics Measurements (HSR-4), 

Institutional Industrial Hygiene and Safety Group (HSR-5), Nuclear Criticality Safety (HSR-6), 

Information Management (HSR-7), Operation and Facility Support Group (HSR-8), and 

Radiation Protection Ser vices (HSR-12). HSR-12 includes the Radiological Engineering Team, 

the Radiation Dosimetry Records and Reports Team, the Dose Assessment Team, the Policy and 

Integration Team, and the NTS Support Team. The Dose Assessment team is a part of R adiation 

Protection Services (HSR-12). Their primary function is to group workers referred to them in 

order to perform internal dose assessments based on bioassay data and other pertinent field 

information. They are responsible for calculating internal dose for plutonium and americ ium for 

workers past and present. For other nuclides, doses are calculated for current workers for the 

current year. 

LANL currently uses the Facility Manager Unit (FMU) Concept. There is a single Radiation 

Protection Program plan for the site. The various facilities onsite may implement the 

requirements in different ways. The Facility Manager is responsible for ensuring all 

requirements for the particular facility are met. They negotiate with HSR-1 to obtain appropriate 

RadCon support. 

Workplace Radiation Monitoring 

The early Radiological Control Organization was spread throughout the plant. The Radiological 

Control Technicians (RCTs; formerly known as radiation monitors) and their supervisor were a 

part of Radiological Fields Operations (HSR-1). At one point in time, the site maintained a 

central pool of radiation monitors who were cross-trained to work throughout LANL. Prior to 

the mid-1990s, radiation monitors ga ined their knowledge through experience rather than formal 

training. This experience taught them what to expect from situations they encounter. In the 

1990s, there was a gradual improvement in the Radiation Protection Program based on revised 

Radiation Protection regulations. RCTs were provided with improved instrumentation and 

formal training. 

Radiological Control Technicians (RCTs) had responsibilities for more than one area at a time 

prior to the Tiger Team assessment. They were responsible for maintaining shift logbooks of 

daily activities. Any task related to radiological control (e.g., surveys, air sampling, incidents, 

etc.) was documented in these logbooks. The historic logbooks were sent to the TA-35 arch ives. 

RadCon Operations documents incidents or unusual events in the logbooks, on surveys, and on 

what is referred to as a Radiation Incident Report (RIR). Historical field records are not well 

organized. 

Prior to the requirement of Radiation Work Permits (RWPs), usage varied by facility. For 

example, LANSCE had a permit of some type back in the 1970s; whereas, there was only limited 

use of permits in the early years of TA-55. A majority of the employees in the radiological 

zones follow work in accordance with the rules set forth by the Radiation Work Permit. 

Requirements were determ ined from field conditions. 
 

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Radiation monitors were responsible for performing radiation and contamination surveys. 

Surveys included routine, pre-job, post-job, and special measurement of alpha, beta, gamma , and 

neutron radiation. Another responsibility included job coverage for glove changeouts, High 

Efficiency Particulate Air (HEPA) filter changes on glove boxes and hoods, and other high-risk 

jobs. Survey frequencies varied. For example, at TA-21 there were daily alpha surveys, 

biweekly beta/gamma surveys, and monthly neutron sur veys. Survey results are posted at the 

entrance to an area or on the hoods (usually written on the posting) to alert workers to the 

radiological conditions. 

The portable radiation instruments used for contamination surveys include the Ludlum 139 an d 

the Eberline 530. Sources used for instrument calibration include a Cs-137 source, a Co-60 

source, and a Cf-252 source. The neutron source is portable. Calibrations are the respons ibility 

of the HSR-4 group. In the early days “the Cow” was the neutron instrument of choice and wa s 

developed at Los Alamos by Dale Hankins. This unit was designed to measure a dose equ ivalent 

in rem for fast neutrons u p to about 8 MeV. 

Original air samplers were the old Filter Queen air samplers with 4” x 9” filters. The hazard in 

the area determined whether the filter was analyzed for beta, photon or alpha, or all types of 

radiation. For this particular area, the filters were analyzed for only alpha. Air samplers 

eventually changed from the Filter Queens with the 4” x 9” filters to 2” fixed air head samplers 

operated by vacuum pumps. This meant there was an increase in the number of filters to be 

counted. Job-specific air sampling was done using Giraffe Air Samplers. These were placed on 

carts so they could be moved to the job site. Giraffe samplers consisted of a filter holder 

mounted at the end of an extendable tube connected to a vacuum pump. Site experts indicated 

that if a fixed-air head filter read over 5,000 dpm, the RCTs were told not to send it to the 

counting lab and to dispose of it in the radioactive trash. Howard Eberline later developed a 

Continuous Air Monitor for high-risk jobs. Air sample results were documented on a Special Ai r 

Test form that described the area and job, and included monitoring and airborne test results. 

Protection measures including Personal Protective Equipment (PPE), engineering controls , and 

administrative controls have changed over time. Individuals are more involved in work 

planning. Historically, the workers were not told what material they were working with; 

however, the workers are now more cognizant of the hazards and materials with which they 

work. PPE has ranged from laboratory coats or coveralls to Bubble Suits. When an individual 

exited contamination or potential contamination areas, they were required to self monitor the ir 

hands and booties. If either of these were contaminated, a Radiation Monitor was called. 

The current contamination control procedures at CMR are extensive. Individuals who work in 

labs don PPE, including booties, lab coats, and taped gloves. In some situations, more 

substantial PPE is required, including the use of respirators. There is a survey meter mounted on 

hoods to monitor hands and arms each time they are removed from the hood. Lab coats are 

surveyed and stored in the lab. Personnel leaving the lab doff their PPE and check for 

contamination on a Ludlum 214 hand and foot monitor. A final survey of personnel and 

personal effects were completed with personnel contamination monitoring. With other areas of 

the laboratory, there may be an RCT covering the job that provides contamination monitoring 

support. 
 

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Respiratory protection is often used for invasive work in operating areas. There are jobs for 

which respiratory protection has been changed over time. In some situations, PPE and 

respiratory protection were initially not required, but later were determined to be necess ary. For 

example, historically, the DP tunnels were considered uncontaminated; however, later it w as 

determined they were contaminated. Initially, no PPE was required. Later PPE and a respirator 

were required. Although radiological tape and ropes are established around an area, there is no t 

always an air space between those in PPE and those not. 

Lead aprons are worn during transportation of material or in the bagout rooms. Dosimeters w ere 

worn under the apron. The aprons were effective in reducing gamma exposure, but had little 

effect on neutron exposure. 

Currently, items coming out of radiological areas are surveyed or property bagged to contain 

contamination. Any conduit or wiring in the controlled area stayed in the controlled area until it 

was properly bagged out. 

No eating, drinking, smoking, or gum chewing have been allowed in radiological areas at least 

since the early 1980s; however, this was prevalent prior to that time. Eating, drinking and 

smoking were allowed in the Main Shops. Security Guards spend 11 hours per day at the TA-21 

Orange Room, which had visible dust and chipping paint. They were not allowed to leave this 

post. This meant meals and beverages were consumed in this area, surrounded by dust from 

various metals and radiological contaminants. 

Radiological areas are maintained under negative pressure with HEPA-filtered exhaust systems. 

Operations in CMR used acids in the glove boxes and hoods. As a result, the exhaust system 

was corroded by the acid. When this occurred, the area was patched or replaced. Prior to th e 

repair, leakage of material from the system would occur. Starting in the 1940s, shielding was 

utilized throughout the site to control external exposure. For example, accelerators such as 

LANCSE are well shielded to reduce exposure. In cases where engineering controls are 

available, such as during a line cut, the laborato ry employees use glove bags. 

Although much of the work was performed in hot cells, by distant remote control, reactor fuel 

testing required some hands-on operations. Glove box leakage was not a routine problem exce pt 

in the case where holes formed in gloves. At times, holes would form in the gloves when 

working with metal. There were quite a few of these occurrences over the years. These would 

be documented in incident and accident reports. There were also cases where product was 

dropped either in the glove box or when it was handled outside, creating spills. 

Employees working overtime had the potential for extended exposure to radiological materials 

and toxic chemicals. Overtime varied by job responsibility and time period, but ranged from 

zero to 40 hours per week. If fact, security personnel went on strike in March 1969 alleging 

unfair labor practices on the part of Mason and Hanger which included overtime issues. 
 

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External Monitoring 

The external dosimetry group has compiled a group of notebooks on the historical external 

dosimetry program. Included in this documentation is a description of formerly used dosi meters, 

external dosimetry procedures and practices, and comparisons between albedo dosimeters and 

film. This compilation of documents is sometimes referred to as the Dosimetry Bible. The 

current dosimeter is described in detail in the external dosimetry TBD. 

The external exposure at LANL can be best characterized as chronic except in cases of incidents 

or non-routine jobs. There was a change in the number monitored for external exposure over 

time. Initially, 1 in 10 were monitored, then 1 in 5, then nearly everyone. Both hands-on and 

support workers have historically been assigned dosimeters. For jobs where there was a high 

potential for exposure, pencil dosimeters were assigned in addition to the whole-body dosimeter. 

Currently, the lab implements a Health Physics (HP) Checklist used by the employee and 

employee supervisor to determine whether external monitoring is required. External monitoring 

is conservatively implemented with about 75% of the personnel being monitored at the present 

time. There are some individuals who do not enter radiological areas and who are not monitored. 

In the past, DOE has indicated to LANL that they were issuing more badges than necessary. 

About 90% of the dosimeter results are zero, currently. Collective dose at LANL compared to 

other DOE Facilities is larger because LANL is actively involved in production work. 

The predominant sources of occupational external exposure have been DP West and TA-55. The 

highest current dose comes from the bagout process in TA-55 and other manual operations. The 

firing sites contribute around 150 mrem/year to worker dose. The Chemistry staff interviewed 

indicated their external dose peaked at 200 mrem/year based on operations performed s ince 

1990. It is not uncommon to see Chemistry staff with external doses significantly below 

100 mrem/year. The dose received is directly related to the time spent in the lab. Site experts 

indicated that about 50% of the time worked is spent in the laboratory. 

Individuals were directed to wear their dosimeter between their neck and waist. In more rece nt 

years, the dosimeter was worn on a lanyard, with the exception of LANSCE, where it was 

reported that employees often wore the dosimeter on the collar. The dosimeter is not held flush 

with the body. Geometry may be an issue at LANSCE because PICs an d badges were worn on 

the collar when working, although radiation sources often were at waist level (e.g., magnets and 

targets). Some individuals put their dosimeter in the pockets of their coveralls for hot jobs. 

Interviewees indicated that taking their dosimeters home was the norm. TA-55 does have a 

badge rack. 

External dosimetry does not have an incident database, per se. There were no other major 

external dose incidents except the criticality accidents. Workers were occasionally put on 

radiation work restrictions and reassigned to non-radiation work due to excessive exposure. 

There was an investigation process for missing or damaged dosimetry, as well as for dosimeters 

with unusual results. There is also a process in place where a worker may have a particular 

dosimeter reading investigated if the worker questions the result. There have been various 
 

 

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investigations related to leaving dosimeters in lockers or in the hallway. They can pick up 

thermal neutron exposure in some areas if badges are put in hallways. 

Pocket Ionization Chambers (PICs) were used to monitor day-to-day exposures for dose-tra cking 

purposes. If PICs were worn, they were collocated with the dosimeter. Sometimes, stay tim es in 

the area were very short. When workers got in, around, and over equipm ent at the accelerator, it 

was not uncommon for PICs to go off scale. The PIC used at the time had a 90 mR range. There 

were other times, where in similar situations, PICs were not used. When workers are assigned to 

TA-55, PICs are assigned in addition to the primary dosimeter. These PICs are turned in daily. 

There is no time-keeping data to the knowledge of current RadCon personnel. HSR-1 is 

responsible for maintaining these records. 

There have been studies completed comparing pocket ionization chambers (PICs), electronic 

dosimeters, film badges and TLDs. PICs were usually assigned for short periods of time ( i.e., a 

job) and could over-respond by as much as 50%. There was a correction factor that was used to 

compensate for this over-response; however, it is not clear that the RCTs always used it. The 

PIC responded to only photons and would under-respond in areas where there was some level of 

neutron exposure. Primary dosimeters and electronic dosimeters typically agreed with one 

another. If there was a difference, the electronic dosimeter read slightly higher. 

Neutron Dosimetry 

There are neutron generators housed at various facilities around the site. Californium-252 is 

used as the current calibration source for neutron dosimeters and instruments. Source recovery 

has also collected sources no longer needed by groups. Historically, LANL had accelerators 

(e.g., LANSCE, Van de Graaff), reactors, critical and subcritical assemblies (i.e., TA-18), 

plutonium processing areas (e.g., TA-21, TA-55), initiator production areas, and research and 

development activities that potentially contributed to neutron exposure. 

LANL conducted studies that included evaluation of the neutron flight path and neutron sp ectral 

measurements. In the 1950–1960 time period, beta, photon, and neutron measurements were 

made to determine correction factors by location. In the 1970–1980 time frame, neutron-togamma dose rate measurements were made at various facilities. These measurements provided 

extremity and specific neutron correction ratios based on the location an employee worked. 

There were several types of neutron measurements that were associated with the reactor 

program. In one case, the radiation exposure to a plastic dummy was measured at Godiva at a 

peak power burst. A series of Bonner Sphere measurements were made in various areas. 

There were conditions where neutron energies were high enough that the NTA film meas ured 

dose fairly accurately. The track in the film could indicate the energy of the particular neutrons 

encountered, especially high energy neutrons. There were other areas where thermal neutro ns 

were predominate, and NTA film could underestimate neutron dose. There were significant 

neutron exposures at LANSCE from a wide range of neutron energies. The alpha-neutron 

reactions in areas of TA-55 produce thermal neutrons that would not be measured by the NTA 

film. The most common neutron energy at LAMPF was about 1 MeV based on spectral studies . 
 

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Neutron exposures at LANL were typically chronic exposures with personnel being expose d to 

low dose rates for long periods of time. 

During the period when the lab was rebuilding Little Boy, several individuals from various 

facilities were invited to do neutron measu rements. This served as information for the
 

Hiroshima/Nagasaki dose assessment and helped determine the neutron quality factor. This data 

was presented at a symposium held at Hanford. 

Neutron dosimetry was assigned intermittently for work in some facilities, such as TA-55, CMR, 

TA-21, and TA-3-31. For example, when one si te expert was doing analyses for the Cassini 

Project (contains Pu-238) in TA-55-PF4, he received a neutron dosimeter for this period of time. 

There was an enhanced awareness of the higher specific activity with Pu-238. 

In 1960–1970, Dale Hankins worked on the development of the albedo dosimeter. He later went 

to LLNL where he developed track etch dosimetry. There have been neutron dosimeters with 

and without cadmium shielding. It was determined that the dosimeters without cadmium 

shielding had the maximum sensitivity. 

A significant neutron dose reconstruction project was conducted for RFP in which the nuc lear 

track plates (NTPs) were retrieved and re-evaluated. Although the NTPs are available, the 

emulsion was falling off. LANL’s historical doses have not been called into question like those 

for RFP. There was some experimentation with Track Etch dosimeters to determine whether 

they were effective with high energy interactions. 

LANL has an Area Dosimetry Monitoring Program. These dosimeters are placed in the 

plutonium facility, x-ray surveillance areas, and wh ere radiation generating devices are used. 

The need for area dosimetry is decided on a case-by-case basis. 

Skin Dose 

There were areas onsite where beta exposure was a concern. The primary beta exposure at 

LANL was associated with uranium operations, such as machining uranium parts. 

Phosphorus-32 was handled in small quantities in the bioscience area as a tracer. There was a 

major contamination incident in the past involving an intern who tracked P-32 throughout o ne of 

bioanalytic laboratories. Most of the skin contamination events that have occurred a t LANL 

involved alpha emitters. The evaluation of skin dose from contamination incidents is performe d 

on a case-by-case basis. This area of external dosimetry is continuing to be developed. 

Extremity 

The Radiation Operations group was responsible for identifying nonuniform fields and 

determining whether multi-badging was required. LANL did not use multiple dosimetry systems 

through at least 1982. The use of multiple dosimetry from 1982 forward was rare. The method 

of dose assignment was on a case-by-case basis. 
 

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Wrist dosimetry was assigned based on the quantity of radioactive material being handled. 

Machinists and those working hands on with mater ial were assigned small thermoluminescent 

dosimeters (TLDs) worn on the fingers or fingertips. With smaller quantities of material, 

extremity dosimetry was found to be unnecessary. The maintenance staff interviewed indica ted 

that they did not receive routine extremity dosimetry. Wrist dosimeters replaced finger rings fo r 

monitoring extremity dose beginning October 1998. 

Internal Monitoring 

The period of time covered by the Internal Dosimetry function at Los Alamos extends back to 

the earliest days of the laboratory. Historically, individuals who worked with 1 Curie of Am-241 

or Pu-238 and Pu-239 were placed on the urinalysis program. The current internal dosimetry 

program operates at standards above and beyond the Department of Energy Laboratory 

Accreditation Program Standards. Health Physics Operations (HSR-1) does preliminary 

evaluations to determine if there is a possibility of an individual receiving 100 mrem CEDE or 

more. If this is the case, individuals are put on a urinalysis program. If they are expecte d to 

receive less than 100 mrem CEDE they are not put on a bioassay program. Virtually every 

current radiological worker at the site has some bioassay data. 

The radionuclides of concern by area are based on the dose coefficients for the particular 

radioactive material and the amount present. When employees a rrive at LANL, they are asked to 

submit a baseline urine bioassay sample. The monitoring program for the DP-West area 

included assignment of beta/gamma dosimeters, assignment of neutron dosimeters, submit tal of 

bioassay samples for plutonium and uranium, and collection of routine air samples. 

Maintenance, Operations, and Radiological Control staff were on a routine bioassay progr am. 

The internal monitoring among maintenance personnel varies. Some individuals sub mit annual 

or semi-annual urine samples for plutonium; others had no bioassay (in some cases, it had been 

discontinued years before). Those on plutonium bioassay also receive a whole-body count. 

Some individuals submitted bioassay samples up to monthly. They were unaware of the 

particular radionuclide of concern in this case. When individuals entered the tritium laboratory 

area, they were not always required to submit a tritium bioassay sample upon exit. In some 

cases, individuals received only a single whole-body count during their period of employm ent. 

Crafts personnel interviewed indicated that even among the same craft, there was a variation in 

bioassay requirements even though they performed the same type of work. Chemists receive d an 

annual whole-body count and participated in semi-annual urine bioassays. Four bottles are 

provided for the collection of bioassay samples. They are given 2 to 3 days to fill them and brin g 

them back. In the case of incidents, special whole-body counts, lung counts, or bioassay samples 

are requested. 

There were various chemical forms of plutonium used at LANL. Plutonium used at LANL 

includes aqueous solutions, such as plutonium nitrate and plutonium metals. During an incident 

in 1970 in Wing-9 of the Chemical and Metallurgical Research Building, the Dose Assessment 

Team observed a peculiar behavior in the plutonium excretion. The initial urine excretion w as 

small, but then increased over time. In experiments with dogs it was found that the 

monodisperse aerosols deposited in the lungs were fragmenting due to the high specific activity 
 

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of Pu-238. This is the reason for the increase in excretion rate over time. An additional 

biokinetic model discussed in the TBD is included for Pu-238 in order to describe th is behavior. 

Tony James derived a similar model in a paper published in Health Physics. When an intake 

involved Pu-238, there was an assumption that this modified biokinetic model may apply . This 

has not been observed with Pu-239. LANL has not identified situations with high-fired uranium 

oxide. 

Los Alamos has developed an ultrasensitive bioassay technique to identify intakes of Pu-239 

and/or americium. This can lead to detection of small intakes not previously seen with other 

bioassay techniques. If high-sensitivity measurements suggest that an individual had an 

undetected intake while at LANL, the lab will collect follow-up bioassay samples for evaluatio n. 

There are some retirees with known intakes that the lab continues to monitor. 

In-vivo counters are located in the Health Research Laboratory (HRL). In-vivo monitoring was 

primarily established for detection of fission and activation products. According to LANL health 

physics staff, all individuals on a plutonium urine and/or fecal monitoring program also receive 

lung counts. This was not always the case, historically. In the case of incidents, special wholebody or lung counts were requested. 

Determining plutonium intakes with a lung count was dependent on the americium present in the 

mixture. There was no standard ratio b etween the americium and plutonium, as these ratios vary. 

LANL performed many chest counts for Am, but few bioassays unless workers were handling 

pure americium. Up until recently, in-vivo counts were recorded as being less than the detection 

limit (“no detectable activity”), and were not analyzed statistically to search for low-level 

intakes. They have used historical individual americium chest count data on a “case-by-case” 

basis, where individual dose analysis needs to be done. 

Nasal smears were used to track potential intakes and were collected when a potential for intak e 

existed. For example, within the DP West area nasal sm ears were taken at the end of the work 

shift. Everyone in the area had to submit them. If an individual exceeded an action limit, an 

investigation occurred and employees were asked to submit a special bioassay. These special 

bioassay samples could be requested by either field personnel or the Central RadCon group. The 

action level changed to 50 cpm in both nostrils in 1946, and remained at this level until 1982. 

This level would no longer be tolerated. 

Although DAC-hour tracking may be used as a trigger, it is not used for dose assessment. The 

levels of triggers for DAC-hour tracking and other means of indicating potential intake are 

documented in the LANL Internal Dosimetry Technical Basis Document. If there is some 

question whether an individual may have had an intake, the Radiation Protection group err on th e 

conservative side and collects bioassay samples. 

LANL is responsible for monitoring all employees, subcontractor employees, and visitors to the 

site. Everyone who submits a bioassay sample is assigned a Z number and a PID number. There 

is a single database that includes information for all monitored individuals. Zia workers were 

treated the same as any other LANL employee. To track and manage the collection and analysis 

of bioassay samples, the site implemented the Urine Tracking System (UTS) database in the 
 

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early 1990s, which was replaced in 2003. The current bioassay database is inclusive of both in ­

vivo and in-vitro results. There were measurement uncertainties associated with the original 

bioassay data. The plutonium bioassay data, with uncertainties, has been put into an electroni c 

database and extends back to 1944. This database also includes Am-241 urine results. There are 

a few cases of large historical Po-210 doses at LANL. 

When intakes of soluble uranium or tritium occurred, individuals working in this area were told 

to drink a lot of beer (or other liquid). This flushed the material out of the system. 

Environmental Monitoring 

The monitoring stations are numerous and change from year to year. The annual environmental 

reports list the monitoring stat ion locations for a given year. Some stations are located close to 

the source and do not directly represent potential exposure to general workers. Some are also 

placed in restricted areas not accessible to general workers. There are 40–60 air samplers in the 

perimeter of the site and offsite. These are integrated air samples that capture emissions from 

multiple areas. Ambient air monitoring filters have been analyzed for americium, tritium, 

plutonium, uranium, gross alpha, and gross beta. All these analyses were not initiated at the 

same time. 

In the 1990s, there were 30 stack monitors. Prior to this, there were more stacks with 

monitoring. Particulate, charcoal, and grab samples (H-1) were taken to monitor effluents from 

the Omega Reactor while it was in operation. Some early stacks (1940s) were unfiltered. It 

appears that some stacks on top of D Building were filtered. Evaluation of the building 

committee meeting minutes from TA-21/DP West indicates that these facilities underwent 

modification and improvement in ventilation. There is an ongoing investigation by the 

LAHDRA project into what type of filtration was present historically, especially for TA-1. 

Eventually, high efficiency particulate air filters and/or bag filters were installed at facilities . 

Controls for environmental emissions site-wide are continuously improving. 

The main dose contributor to the maximally exposed individual (MEI) offsite is due to the 

releases from TA-53, LANSCE. Initially this facility had no stack monitoring . Ninety percent 

(90%) of environmental emissions came from Area A targets and can be attributed to short-lived 

activation products, such as C-11, Ni-13, and O-15. The dose is from the decay of positron 

emitters and the subsequent emission of 511 keV gammas. Using conservative assumptions in 

the early years, the dose from the LANSCE plume was estimated at 2.5 mr/hour. This was 

measured while the beam was on in the radiological areas within 200 m of Area A. Dose rates 

received by general workers located more than 1 km to the west were monitored by RCTs and 

were less than 100 mrem/year. 

During the past 30 years, the most significant releases have been the gaseous activation product s 

from TA-53. During the early years, the most significant releases were transuranics from TA-21. 

Information on releases from TA-1 during the 1940s is not readily accessible or does not exist. 

Off-gassing of C-11 from LANSCE caused a release of this material to the environment. There 

were also releases of iodine from the accelerators. There were massive environmental releases 
 

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of tritium from the TA-33 Tritium Facility. This facility was eventually shut down in the 1980s 

due to these releases. 

There is contamination in alluvial groundwater, but this is not drinking water. The 

contamination in the aquifer is minimal and contributes a dose of <0.1 mrem/year to the public. 

Gross alpha and gross beta analyses are done for drinking water. Other radionuclide -specific 

analyses are also performed. The most substantial spills of radioactive material to the 

environment occurred in the 1940s and 1950s. Details on spills are documented in LANL 

reports. 

The New Mexico Environmental Department performed monitoring activities at and around 

LANL. Data was mostly used to check LANL results. Occasionally, they measure something 

LANL misses. In this case, LANL confirms their data. The state of California has no 

jurisdiction over LANL. The Agency for Toxic Substance Disease Registry did perform some 

perimeter air monitoring on Pueblo lands, although the quality of this data is unknown. 

There was some monitoring in the earlier years (1940s), documented in memos and prog ress 

reports, but these are not readily available. During the later years, the environmental monitoring 

program is described in the annual reports, which are available electronically. Annual 

environmental reports include both routine and episodic releases. 

Natural background measured by environmental TLDs ranges from about 100 to 200 mrem/year 

depending on the location. An annual dose of > 200 mrem/year indicates there is possibly a 

contribution to external dose from LANL that requires further investigation. Background from 

natural terrestrial and cosmic radiation is subtracted from the LANL TLD data. No background 

studies were completed in the 1940s prior to operations that those interviewed recollect. 

The environmental dosimeters are collocated with the air samplers to measure ambient ex ternal 

dose. Radiological Control Technicians (RCTs) also perform surveys with hand-held 

instruments in locations where workers spend a significant amount of time. RCTs ensure that th e 

General Worker dose is less than 100 mrem/year. The TLDs in TA-3 that showed high doses for 

2000 and 2001 were located inside a fenced, locked, and posted area. The dose to workers and 

the public was calculated from the TLD measurements and was reported in the annual 

environmental reports. The high doses measured in this area from 1975–1980 may have been 

from the Van de Graaff accelerator. TLDs were placed about 10 m from the lagoons, w hich 

were situated toward the east end of TA-53 where LANSCE is located, even though there is no 

regular access to this area. The nearest occupied office is greater than one kilometer to the w est 

of the lagoons. These TLDs were used to calculate the doses at more distant locations. 

Environmental Dose to a General Worker from LANL operations would likely be < 100 mrem 

per year for someone who has not entered a radiological area. 

During 1944 and 1945, Hillside 138 received untreated waste f rom TA-1 (Building D). This 

area has the worst potential for resuspension. Comparable locations onsite are the Material 

Disposal Area G and TA-21. There are air sampling stations near these locations to measure 

potentially resuspended activity. The resuspension of soil results in negligible dose (< 0.1 

mrem/year.) Although the data often show significant contamination, this contamination exte nds 
 

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over < 1% of the area of LANL. Aerial surveys of the laboratory were conducted in 1989 a nd 

1998. 

Incidents/Accidents 

Historically, RadCon generally responded to incidents or accidents in full or half-face 

respirators. They would observe the conditions of the area and collect the air sample filters. 

Where decontamination was necessary, the specially trained janitors came in and clean ed up the 

area. Information was collected from the room supervisor. After the cleanup, there was a 

follow-up survey. Incidents and accidents were documented in an Incident Report or Accident 

Report. The information included the date and time of the incident, the radiological 

measurement results, a description, and the names of persons involved. These reports were sent 

to the records repository. These types of records were supposed to be maintained ind efinitely. 

An individual’s collection of hardcopy incident files is available from 1944 through the early 

1991. This does not constitute a formal incident collection and may not be comprehensive. 

HSR-1 maintains a database that covers a wider base of incidents including those not resulting in 

personnel exposure. This incident dates back to the early 1990s. The database contains 

Radiation Incident Reports (RIRs) that are maintained on any type of incident whether 

individuals were exposed or not. These reports include items like unusual events, continu ous air 

monitor alarms, nasal smear records, etc. Once the RIR database was adopted, hardcop y incident 

reports were not maintained. An incident identification number is assigned to each entry in the 

database. This reference number allows cross referencing with the Dose Assessment incident 

database. Incidents are also traceable to the early hardcopy incident files maintained by 

Radiological Records. 

When an incident occurs or a trigger level is hit, HSR-1 notifies the Dose Assessment Team and 

provides them with a description of the incident, type of material, nasal smear results, air 

sampling results, in vivo count data and other pertinent information to dose assessment. The 

incident is entered into an Incident Database. Special bioassay is assigned, according to c riteria 

established in the Internal Dosimetry Technical Basis document. The Incident Database 

maintained by the Dose Assessment team contains all known electronic records of incidents for 

plutonium and americium. According to the LANL Dose Assessment team, all dose asso ciated 

with incidents is incorporated into the dosimetry database. 

Several incidents or unusual occurrences mentioned by site experts are included below. Some of 

these events were documented formally while others were not. 

• 	 There was an explosion associated with the Phoenix Pro ject in 1990 that blew the glass 

out of a glove box. The cleanup crew was required to wear three pairs of anti-C’s and 

self-contained breathing apparatus (SCBA). The room was closed for six months for 

decontamination. RCTs received elevated exposures during the recovery process. This 

incident is documented in an occurrence report. 

• 	 In CMR Wing 3, there was a small explosion bes ide the open glove boxes. The 

HAZMAT team and Fire Department were called in. 
 

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• 	 In CMR Wing 5 and 7, there were plutonium (green) leaks from the piping. These pipes 

had to periodically be scrubbed down. 

• 	 There were Ballis Tank explosions associated with glove boxes. 

• 	 One LANL employee was fired because he had the x-ray machine on when a SPO was 

doing a security check/clearing on top of the roof. 

• 	 There were times when Security observed loss of negative pressure in the glove boxes. 

• 	 A crew was working on controls and limit switches under the hot cells in CMR Wing 9. 

They were in the process of upgrading controls. For work under the first hot cell, they 

wore supplied air. When it came time to do work under the second hot cell no respiratory 

protection was required. There was a puff of air. One individual ended up with a 

positive uptake. 

• 	 Personnel and clothing contamination has occurred with many personnel. 

• 	 Employees were wounded or burned with acid during work in radiological areas. 

• 	 Continuous Air Monitor alarms would periodically go off in the area. 

The administration of chelation therapy was dependent on the severity of the particular 

contamination event. Los Alamos did not chelate individuals very often; however, when this 

was done, a notation was made in the bioassay database. There was a collaborative effort 

between health physics and medical to determine the significance of the uptake. Based on all the 

data provided, the medical director made the decision on whether to recommend chelation 

therapy. Ultimately, it was the individual’s choice. Anyone receiving chelation therapy had to 

sign a release. 

Zn-DTPA and Ca-DTPA have both been administered to workers at LANL. The administration s 

are primarily in aerosol form; however, intravenous and topical administrations have also been 

given. From May 31, 1992 through May 31, 2005, Medical has administered Zn-DTPA 56 times 

and Ca-DTPA 56 times. These were primarily given intravenously or in aerosol form. There 

have been ten topical administrations over this period of time. The number of administrations 

does not represent the number of individuals chelated. In 2000, a glove box failure occurred 

which resulted in large uptakes by individuals. As a result, there were five individuals chelated. 

Information on the number of chelations prior to this period would have to be obtained from Oa k 

Ridge. 

The Medical Department has procedures for radiation decontamination and treatment. Whenever 

someone comes in with a contamination incident, baseline blood is taken to monitor for blood 

changes that could result from treatment. There have been minor wound debridements or 

excisions at the lab. No lung lavage treatments have occurred to the knowledge of the current 

staff. This information would be documented under the Exposure tab. 
 

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The worst fire to occur at LANL was the Cerro Grande fire of 2000. Releases during the fire 

were small because the significant contamination was underground. Security and emergency 

personnel responded during the Cerro Grande Fire. Many were located downwind of the smoke. 

Security officers worked in all areas of LANL and the town of Los Alamos during the Cerro 

Grande Fire. Officers provided security and ensured that the entire LANL was evacuated. 

Officers conducted roadblocks. Security officers helped to evacuate the town of Los Alamos. 

Officers worked side-by-side with Fire Fighters delivering food, water, etc. 

Criticality Incident 

The most severe accidents at LANL were the criticality accidents. In 1958, operators were 

working on a plutonium recovery operation in Room 218, Building 2, DP-West. An operator 

was trying to treat a tank with nitric acid in an effort to clean it. As was standard operating 

procedure, the operator turned on the stirrer. At this point, he saw a blue flash and was knoc ked 

to the ground. The blue flash was also observed by an individual in an adjacent room. The 

operator managed to turn the stirrer off. Not realizing it was a criticality, the operator turned the 

stirrer on again and heard a rumbling. At that point he exited the room indicating that he was 

burning up. A second and third operator went to help the first operator get to the shower. They 

suspected he had an acid burn. The second operator turned the stirrer motor off. 

A radiation alarm located in a nearby building alarmed. The supervisor called the Radiation 

Monitor in at about 4:30 pm indicating that a RAM had sounded and the situation n eeded to be 

evaluated. As he approached Building 2, he saw three plant operators sitting outside the 

building. This was unusual for the operations staff. One individual’s coveralls were soaked. He 

was complaining of burning up. The Radiation Monitors first thought was also that the 

individual had been sprayed with acid. Most of the personnel were showering and getting ready 

to go home; however, the site was evacuated. 

Upon interviewing the operators working in an adjacent room, he found out that they had seen a 

blue flash through the window. They indicated that the first operator was complaining of 

burning up. 

The Radiation Monitor went down the long hallway in Building 2 to Room 218. He entere d the 

room and note d that there was no displacement of the tank or unusual conditions. Radiation 

readings were taken at various distances and over a period of three days. William Mariman 

(Plant Manager) asked the Radiation Monitor if he thought there had been a criticality accident. 

Readings at 25 feet from the tank were 20 r/hr. 

The individual nearest the tank died 35 hours later. The two other operators received substantial 

acute doses. 

After the situation was under control, the Radiation Monitor realized he had forgotten to put on 

his film badg e. Curiously, it was common to distribute dosimetry records to the field; however, 

during the month of the accident they did not receive a report. 
 

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Medical Exams 

The Medical Division has been referred to by a number of names including H-2, HSE-2, 

QESHA, ESH-2, and HSR-2. Routine medical statistics, such as the number of exams, are fed 

up to the HSR Division for inclusion in reports. Historically, new hires at LANL were given 

extensive exams which included chest x-rays, a pulmonary function test, a hearing test, an ECG, 

a blood test with a chemistry profile and CBC, a urinalysis test to check for proteins and white 

blood cells, a vision test, and a general head to toe physical assessment for general health. In the 

past chest x-rays were done every year. Both a posterior-anterior and lateral view was taken. It 

was later realized that there would not be a significant change in the lung views within a single 

year so they began spacing them out. X-ray films for employees have been maintained in 

storage. 

In the last 8–10 years, Medical has eliminated most routine physicals except in the case of 

individuals in Certification or Surveillance programs. Routine periodic physical exams are 

primarily for those individuals involved in Surveillance and Certification programs. Surveillance 

exams include those for individuals working with asbestos, carcinogens, beryllium, or other 

substances named in Occupational Safety and Health Administration regulations. Certification 

exams are given to individuals using respiratory protection including Self Contained Breathing 

Apparatus, or those requiring verification of fitness for duty, such as the Protective Forces or 

Department of Transportation (DOT) staff. A specific surveillance program may require specific 

tests, such as x-rays for asbestos workers, LPTs for beryllium workers, and blood lead levels for 

lead workers. 

The frequency of these exams varies by the certification or surveillance program. For example, a 

DOT certification occurs every two years. The exam requirements for use of respiratory 

protection are based on age, with older individuals getting more frequent exams. The beryllium 

surveillance program is based on the potential for exposure. Industrial Hygiene is responsible 

for characterizing the environment and providing feedback to the Medical Department. 

Beryllium surveillance exams occur annually or every three years. 

Termination exams were required for all employees at LANL. They are now based on 

information provided by the employee on a medical form. Medical reviews the responses given 

by the employee with regard to his/her work experience and evaluates their medical file. After 

this review, it is determined whether a termination physical is required. 

From 1983 to 2003, the Medical Department used a General Electric Model DXD-35011. This 

unit was a single phase unit. In 2003, the Medical Department changed to a digital x-ray system. 

This unit was triple-phase high frequency unit. The mammography unit used at LANL was an 

Electric Senographe 600T Mammographic X-ray system. Mammography was provided to 

women as a preventative for a short period of time at LANL. Current medical staff was 

uncertain what equipment preceded the GE Model DXD-35011. There are no portable medical 

x-ray units or other sources of radiation (e.g., teletherapy units) associated with the medical 

department. Current Medical staff indicated that there was no photofluorography at LANL. 
 

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The Radiation Protection Group (HSR-12) is now responsible for medical x-ray equipment 

inspections. Up to July 2000, this responsibility was carried out by the Food and Drug 

Administration (FDA). The manufacturers also provided maintenance support. 

Note: The FDA determined the retake rate for the General Electric unit to be 2.5%. With the 

new digital unit, retakes are rare. 

Radiological Records 

Radiation Dosimetry Records and Reports is responsible for maintaining historical and current 

dosimetry. This group also maintains occupational exposure records from previous employers. 

Bioassay records are maintained by HSR-4. 

Areas on the site are known by three different designations: the Technical Area, the Descriptive 

Name, and the Group Number of Designation of the primary group in that area. This makes 

interpretation of records somewhat more challenging. There are also several abbreviations that 

may be encountered in historical records. Several are provided below. 

• Oralloy Enriched uranium 

• Tuballoy Tube Alloy 

• D38Depleted Uranium 

• UNatural 

• U-235 

• U-238 

• Np-237 

• Pu-238 

• Pu-239 

• WAWeapons Assembly 

• GT Gary Tenni 

This nomenclature goes back to 1942. Isotopes were assigned a two-digit number with the first 

number being the second digit of the atomic number and the second number being the last digit 

of the atomic mass. 

Internal and external monitoring data is stored in a relational database. The external dosimetry 

data goes back to 1944. The plutonium bioassay data is also available back to 1944. There are 

some radionuclides that are not in the main database, such as polonium. The database is backed 

up nightly and hardcopy listings of the data are available from 1944. There are about three 

million dosimetry records. Measurements below the detectable level will show up as zero in the 

dosimetry records. The original dosimetry records were recorded in laboratory notebooks. The 

information in these notebooks has been converted to electronic form. The original notebooks 

were sent to archives. 

The dosimetry records include skin dose, shallow dose, penetrating or deep dose, neutron dose, 

whole-body dose and tritium dose. These dose elements are defined below. 
 

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Skin dose = shallow dose + neutron dose + tritium dose 

Shallow dose = open window (beta/photon) dose 

Penetrating or Deep dose = shielded (photon) dose 

Neutron dose = thermal neutron dose + fast neutron dose 

Whole-body dose = deep dose + neutron dose 

Tritium dose is reported as a separate component 

In the database, the dose components are listed on a single line. For situations where more than 

one wrist dosimeter is worn, the highest dose is assigned as the extremity dose. Results from all 

extremity badges are available. 

Z-numbers/PID numbers are assigned to those monitored onsite. In the mid-1990s, all previous 

employees without Z-numbers were assigned Z-numbers and PID numbers. This included 

previous employees, contractors, and visitors. The Z-number can be used to query a particular 

individual’s record. Z-numbers can be cross-referenced to other databases, such as the personnel 

database. With this cross-referencing ability, one can determine demographic information and 

primary work location. Assignment of the primary work location may not be the actual worksite 

of an individual, such as those that provide support throughout the site. 

Some job classifications information can be obtained from external dosimetry records. Mail 

stops can give some indication of where an individual might be located, but this is not full proof. 

There are also group codes and the HP employee checklist that may assist in determining work 

location. With Zia employees, it would be more difficult to track down work locations. 

Records have been modified over time for various reasons (e.g., additional bioassay data, dose 

investigations). Dose investigations were triggered out of HSR-4 when there were questionable 

results, lost and damaged dosimeters, and when dosimeters were not returned. Results were 

reviewed by the supervisor, the employee, and dosimetry personnel. When the dose 

investigation was signed by all required parties, the dose of record was changed. No dosimetry 

or bioassay records were destroyed. Dosimetry records have not been removed from the site at 

any time. 

In addition to plutonium data, tritium data and uranium bioassay data for some years have been 

included in a database. The tritium data is reported separately. This data, along with the 

plutonium data, has undergone quality control checks. LANL has pulled together what is 

available for tritium bioassay data. There is a database containing Po-210 bioassay information; 

however, it still requires some quality control checks. Jim Lawrence did considerable work to 

develop electronic databases, e.g., for Po-210. Some identification cannot be linked back to 

Z-numbers due to the ambiguity of workers’ names. For example, there may be two Jim Smiths 

with no middle initial. The quality control verification of Po-210 data is not a high priority, as it 

deals with historical data. Bioassay data available in hardcopy includes gross counts, 

background counts, calibration efficiency, and recovery. Historically data was interpreted on a 

case-by-case basis. Current staff is uncertain how results from samples less than the detection 

limit were recorded in the past. 
 

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Medical records do contain some information on radiation exposure. The medical record 

contains a tab for exposures. This section will contain information from dosimetry including 

dosimetry report, in vivo count data, individual specific surveys, information on incidents, and 

medical treatments given as a result of exposures. Incident information provided to medical may 

include a detailed history of the event, the dose assessment, field radiological data, etc. 

HSR-12 has a central repository of information. Field RadCon did not keep their data, but sent 

the information to the archive after a period of time. HSR-12 does not maintain any classified 

records. The relevant dosimetry information from classified reports has been captured in the 

dosimetry database. 

NIOSH is provided with the recorded dosimetry results by badge cycle, available bioassay data, 

and other relevant records available on the claimant. Raw bioassay data rather than dose 

assessment results are provided, so that NIOSH/ORAU can perform their own dose assessment. 

LANL will provide NIOSH with results from multiple dosimetry and/or extremity dosimetry 

where available. 

Radiological Reports 

Annual exposure reports are provided to workers. Workers also have access to their dosimetry 

history online. Annual Occupational Dosimetry Reports have been issued to DOE electronically 

since at least 1993. There were manual reports prior to this. These reports do contain Job 

Classification Codes and Status Codes. The dosimetry department issues monthly external 

dosimetry reports. LANL receives routine dosimetry reports from NTS. This dose was 

incorporated into the LANL reports as far back as the 1980s, but probably back to the 1950s or 

the 1960s. 

Audits and Assessments 

Numerous independent or DOE audits have been conducted of the Radiological Control and 

Environmental Compliance Programs. The Audits and Assessment Group (AA-2) conducts 

some reviews of the Radiological Control program. There is coordination between DOE and 

AA-2 to prevent duplication of effort. Self-assessments are done by the RadCon organization. 

Audits cover eleven functional areas in Radiological Control. Previously, all the functional areas 

were assessed in a single year; however, the Radiological Control organization was told to 

spread them out over 3 years, so that 1/3 of the areas are assessed each year. The DOE Site 

Office Radiological Control Group has the right to perform for-cause reviews. For example, an 

investigation was completed when LANL changed from the use of ICRP 30 to ICRP 60 without 

an approved exemption. The Tiger Team, the Defense Nuclear Facility Safety Board, and other 

outside organizations have conducted independent assessments of the LANL health and safety 

program. During the Department of Energy Laboratory Accreditation Program, several audits 

and assessments were conducted on the External Dosimetry Program. 

Currently, audits focus on the 28 Category 2 and 3 facilities onsite, with TA-55 and CMR being 

focal areas because of high radiological exposure potential. The method for performing audits 

includes multiple steps. The auditor develops an Assessment Plan for the area of concern. Prior 
 

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to starting the audit, a guidance card is provided to the organization being audited. This makes 

them aware of the audit criteria. Following the actual assessment, a written report is prepared 

and provided to the contractor. The contractor then has 30 calendar days to develop a correction 

action plan. This plan requires review and approval by DOE. Each corrective action is 

documented on a finding certificate. Findings and observations from audits and assessments are 

put into the contractor I-TRACK database. This is a Corrective Action Database that allows 

tracking of issues and the corrective actions. Corrective actions are completed by the 

organization and a validation of the corrective action is done. 

Some of the issues which have been identified over the past several years included (1) the 

absence of TBDs for key areas (e.g., Internal Dosimetry); (2) lack of documentation of RadCon 

program elements; (3) out-of-date procedures; (4) the absence of justification for not meeting the 

alpha release requirements; (5) contamination control issues in CMR and TA-55, and (6) a 

shortage of qualified staff including Radiological Control Technicians. There have been 

significant improvements in the RadCon program over the last two years. 

During the Tiger Team inspection, the Tiger Team shut down what was referred to as the TA-21 

Orange Room. This area served as an access control point. The lab stored waste drums in this 

area. There was visible dust and chipping paint. Guards spent 11 hours per day at this post. 

Officers stationed in the Orange Room were not allowed to leave the area. This meant meals and 

beverages were consumed in this area, surrounded by dust from various metals and radiological 

contaminants. “Line X” or the “pulsed radiation experiments” were also shut down as a result of 

findings during the Tiger Team review. 

The LANL Medical Department was the first program in the Department of Energy to achieve 

external accreditation. Accreditation requires that policies and procedures are implemented. As 

a result of this accreditation, there are periodic reviews of the medical program. Prior to 

accreditation, routine audits and appraisals of the Medical Department did occur. 

Chemical Exposures 

There is a wide range of chemicals used at LANL. The type of chemicals used depends on the 

type of work being done. Some of the chemicals utilized included strong mineral acids (HCL, 

H2O2, nitric acid, hydrofluoric acid, perchloric acid, and sulfuric acid), beryllium, mercury, 

asbestos, and lead, to name a few. Although chemists and other employees worked with strong 

acids, it is not typical to see chemical burns. SM-39 Mec-1 Shop 4 and TA-3-39 were facilities 

where beryllium was handled. 

The Fabrication group was involved in the forging of copper during building of the accelerator. 

During copper forging, they used trichloroethylene, freon, and other solvents as degreasers. The 

appropriate personnel protective equipment for the potential exposure was not provided during 

these operations. Offsite doctors have diagnosed cases of Toxic Solvent Disease and other 

chemical related maladies in LANL workers. A number of members of the PTLA force have 

been diagnosed with chronic beryllium disease and beryllium sensitivity. 
 

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LANL hired Eaton Corporation out of Los Angeles to test electrical equipment in TA-55, PF-4. 

The job occurred in 2002 and involved about 15 individuals (6 subcontractors and plant 

employees). Testing a circuit breaker involves injecting electrical current into the breaker. This 

makes the circuit hot and fumes can be released off the circuit breaker. Due to time constraints, 

higher levels of current were used on many of these tests making them even hotter. During the 

job, a LANL employee indicated to one of the subcontractors that a previous spill from a pipe 

near the ceiling had contaminated the wall and the electrical equipment about to be tested. This 

employee indicated that he was simply sharing information and did not know anything further. 

There was other equipment in the room that was also contaminated during this spill. The 

subcontractors were wearing red coveralls and gloves. They were not wearing respiratory 

protection. The job was done at night and did not require a shutdown. Several days after the two 

week job was completed, one worker had to go to the Los Alamos community hospital because 

he was throwing up blood. The illness seemed to get better; however, after a while the 

individual’s health again began to deteriorate according to an interviewee. 

Unauthorized Practices 

LANL operations and management was very receptive to the Radiation Safety group. Field 

Radiological Control (RadCon) personnel generally did not observe unauthorized practices, such 

as eating in the radiation zone. Operations and management were cooperative during and after 

the occurrence of accidents, incidents, or contamination spreads. Personnel wore their film 

badge as required. Historically, when Radiation Monitors identified individuals not wearing 

their dosimeter into radiological areas, they were asked to go back and get it. Individuals in the 

early years that exceeded their MPBBs were transferred to other areas. 

Concerns 

Some interviewed workers have indicated that there may be validity issues with the dosimetry 

records. The dose records do not reflect the exposure conditions as measured by field 

instruments. A number of workers find it hard to believe the zeros measured by their dosimeters 

when they spent so much time in the radiological areas. For example, some of these workers 

point out that despite touring radiological areas, the typical measured dose for guards was zero. 

This does not make sense to those who spent considerable time in radiological areas. Some 

workers are having difficulty getting access to the radiation exposure records. 

There is anecdotal information related to dosimetry data entry problems and entry of zeros. 

Workers have reported that doses in excess of 25 Rem were censored. For example, dose 

exceeding this value would be recorded as 24.9 Rem. 

There are four cases of Lyomyosarcoma within the LANL population. This is a rare form of 

cancer. The four individuals worked at different areas of the laboratory. This was a whole-body 

cancer in the soft muscle tissue. The IREP code and SEC petition law do not include this cancer. 
 

 

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ATTACHMENT 3: KEY QUESTIONS AND RESPONSES FOR 

NIOSH/ORAU REGARDING SITE PROFILE DOCUMENTS 

SC&A submitted questions related to the LANL Site Profile Documents to NIOSH on January 

13, 2006. The NIOSH/ORAU team provided written responses to these questions on March 14, 

2006. Both the questions and responses have been provided below. A summary of the 

conference call conducted between SC&A and the NIOSH/ORAU team with regard to these 

questions is available in Attachment 4. 

Responses to SC&A Questions for the LANL Site Profile Document – 

Introduction, ORAUT-TKBS-0010-1; 

Site Description, ORAUT-TKBS-0010-2; and 

Occupational Medical Dose, ORAUT-TKBS-0010-3. 

The current versions of these TBDs (ORAUT-TKBS-0010-2 and ORAUT-TKBS-0010-3) were 

published with acknowledged data gaps in information to allow processing of selected LANL 

claims. Planned revisions of these documents will include additional information collected since 

the publication of this TBD and any applicable information that comes from NIOSH responses to 

SC&A questions. ORAUT-TKBS-0010-1 will be revised as necessary to reflect revisions made 

to the TBDs. 

Questions and Responses 

General Questions 

(1) Is there a classified version of the Technical Basis Document? 

No. 

(2) In general, what areas could not be included in the TBD for national security reasons? 

How were these compensated for in the TBD? 

Areas would include weapons information. No special compensation has been 

incorporated into the TBD. Most exposures associated with LANL activities 

would have been covered by LANL’s external and internal dosimetry which were 

based on their protocols and practices. Beyond that, NIOSH uses co-worker data, 

TIBs, and environmental monitoring and effluent data to address unmonitored or 

undetected exposures. 

(3) What steps were taken to investigate whether individuals at LANL also received doses 

at the Nevada Test Site, Marshall Islands, Trinity and other test sites? Is dosimetry 

information from these other facilities available in the LANL radiation exposure file? 

This question concerns information that is outside the scope of the LANL site 

profile. 
 

 

 

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(4) Was there movement of LANL personnel between LANL and Sandia National 

Laboratory? Which worker groups? 

Yes, worker movement has occurred and we have been told that it was more 

common during the startup and earlier years of Sandia. Specific worker groups 

are not listed in the TBD. 

(5) Is any of the work history, medical or radiation exposure data for claimants classified? 

Not to our knowledge. Are claimant files being redacted for national security reasons? 

Not to our knowledge. 

(6) What types of claims have been evaluated to date? Without access to a complete 

dataset, how is NIOSH/ORAU sure the reconstructed doses are bounded? 

The first part of this question is outside the scope of the LANL site profile. Task 

3 is not certain as to what is being referred to as the “complete dataset” in the 

second part of this question. 

(7) Which Technical Information Bulletins are applied to LANL dose reconstructions (e.g., 

TIB-0006, TIB-0002, TIB-0028)? 

TIBs are mentioned in the TBDs per the requests of Task 5 and NIOSH dose 

reconstructors. 

(8) How has NIOSH/ORAU verified the completeness and accuracy of the data provided by 

LANL? 

Bioassay data underwent QA/QC during the development of the LANL bioassay 

database. These efforts included sampling of reported urine concentration values 

found in lab notebooks and compared them to values in the database. Review of 

raw counting data, etc. was not part of this effort. 

Regarding external dose, Task 3 did not verify completeness or accuracy of this 

data. This would require review of raw measurement data, etc. The same is true 

for environmental data. 

(9) How have you integrated site expert input into the TBD? 

Site experts such as Jim Lawrence, Bill Moss, John Voltin, Dawn Lewis, Bill 

Eisle, Ray Gilmette, Guthrie Miller, Tom Little, Mike McNaughton, David 

Christensen, and Jeff Hoffman highlights some of the experts that were consulted 

by Task 3. For example, current and former LANL staff assisted Task 3 (Jim 

O’Brien, et al.) in the development of the LANL bioassay database. Much of the 

other information provided by site experts helped to clarify issues related to 

dosimetry and radiation protection programs at LANL. 
 

 

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(10) What was the extent or lack thereof, to which waste management/disposal, maintenance 

and construction workers were monitored for exposure to radiation from 1945–1975? 

Dosimetry may exist for some workers that fall into these job categories. Others 

that were unmonitored partially or entirely will be considered for co-worker data 

and other aspects of the dose reconstruction process. 

(11) During the Manhattan Project, the U.S. government established a secret $1 million 

compensation program for metallurgical chemists and other scientific personnel exposed 

to radiation (Hacker 1987). Were any claims filed under this program, and if so, what 

were their disposition. 

Task 3 does not have knowledge of this program. 

Introduction (ORAUT-TKBS-0010-1) 

(1) Page 6, fifth paragraph, shouldn’t Co-60 be listed here also? 

Not aware that Co-60 is a major source from an environmental dose standpoint. This paragraph 

is addressing ORAUT-TKBS-0010-4. 

Site Description (ORAUT-TKBS-0010-2) 

(1) Page 29 states: 

Gamma dose limits for the time was 0.1 R/day and neutron was 0.01 R/day. 

Based on reported exposures of 20% neutron and 80% gamma, health staff set a 

dose limit of 0.4 R/day by applying a safety factor. 

It would appear that the total dose limit would be 0.110 R/day. How did they arrive at 0.400 

R/day? 

The 0.4 R/d is a transcription error; the correct value presented in the LANL document is 

0.04R/d. The following is an excerpt from the LANL document in question: 

Transcription: 

In studying the health hazard present in Building X it should be borne in 

mind that a neutron exposure measured with a roentgenometer is 

considered to do approximately 10 times as much damage to the body 

cells as the same roentgen exposure by gamma rays. This is due to the 

much grater ionization density along the tracks of the protons produced by 

neutron exposure than along the electron tracks produced by gamma rays. 

Accordingly, whereas the normal tolerance dose for gamma radiation is 

0.1r per day, as measured on the standard Victoreen pocket chamber, the 

standard safe neutron dose is 0.01r, measured in the same way. 
 

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If personnel exposure were due to neutrons alone, there would be little 

question as to the value of the daily dose. However, a great deal of 

gamma radiation accompanies the neutrons. According to measurements 

made be Mr. De Vire (sp?), radiation received by X building personnel is 

composed of approximately 20% neutrons and 80% gamma rays. 

Accordingly, the daily dose has been fixed at 0.04r to include a small 

safety factor. 

This error will be corrected in the planned revision to the TBD. 

(2) Pages 33 and 34 state that early exposure conditions can be found in the Omega 

notebooks (#101 – 733). However, they have not yet been located. Have they 

been located and do these notebooks contain additional dose information not 

contained in the Monthly Health Division Reports or the many Photodosimetry 

Evaluation Books? 

These have not been located according to our knowledge. Task 3 is awaiting a response from 

LANL as to their existence. If located, any information from the notebooks deemed useful will 

be included in the planned revision to this TBD. 

(3) Page 48 states that the monthly Health Group Progress Reports were available 

from Nov 1943 to Oct 1960. However, it appears that later issues are available 

that might provide information for dose reconstruction. Will the later issues of 

the Health Group Progress Reports be used in DR and did the H-1 quarterly 

progress report replace the monthly report?
 

Most of the information in these reports does not alter or is expected to alter how dose 

assessments are being performed. Additional content reviews of these reports will be completed 

to ensure that new information directly useful to the DRs is included in the TBDs. 

In addition to Nov 1943 to Oct 1960, several Health Division reports were released from LANL 

within the last two weeks after their respective classification and legal reviews were completed 

by ADCs. Most of these are unmarked or marked unclassified but were required to go through 

reviews per LANL procedures prior to public release. 

1947: May, July, August, September, October, November, and December 

1948: January, February, March, April, May, June, July, August, September, October, 

November, and December 

1949: January, February, March, April, May, June, July August, October, November, and 

December 

1950: May, June, July, August, September, and October 

1951: January, February, March, April, May 
 

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1952: January, February, March, April, May, June, July, August, September, October, 

November, and December 

1953: January, February, March, April, May, June, July, August, September, October, 

November, and December 

1954: January, February, March, April, May, June, July, August, September, October, 

November, and December 

1955: January, February, March, April, May, June, July, August, September, November, and 

December 

1956: March, April, May, September, and December 

1957: February, April, May, July, and December 

1958: January and February 

1959: March, April, June, July, August, September, October, November, and December 

1960: January, February, March, May, July, August, October, and November 

1961: January, February, March, April, May, June, July, August, September, October, 

November, and December 

1962: January, February, March, April, May, June, July, August, September, November, and 

December 

1963: January, February, March, April, May, June, July, August, September, October, 

November, and December 

1964: February, April, June, July, August 

Occupational Medical Dose (ORAUT-TKBS-0010-3) 

Approach used by Task 5 is summarized in the following table. For questions numbered 1–5, 

this table also provides input from Task 5. The information in this table is guidance taken from 

the current draft of the dose reconstruction guideline for Los Alamos National Laboratory, a dose 

reconstruction tool that has been provided for the use by Task 5. 

Occupational medical X-rays 

Item Action Comment 

Records Not supplied in case file. When Request if x-rays cannot be 

requested give only dates and overestimated. 

views taken. 

Frequency Annual (assumed). Note that Request if case goes over criterion 

actual records show that this is a with assumed annual procedures. 

significant overestimate. 

Views Each procedure from 1957 Tool supplies dose for both views. 

onward had PA and Lateral 

Views. 

NOTE: The calculation tool does all this. 
 

Photofluorography Used through 1956, assume in Not possible to eliminate when 

all cases. actual records are used. 

Best Estimate Based on actual records for Remember to divide the tool values 

occupational medical x-rays by 1.3 (or use the doses listed in the 

only TBD) and assume NORMAL with 

standard deviation of 30%. 

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(1) The introduction to the TBD states that LANL required a pre-employment and 

annual physical for all employees. It indicates that chest x-rays were typically 

included. Has NIOSH/ORAU established whether the protocol for company 

physicals did require a chest x-ray? 

This statement will be clarified in the TBD. Interviews with medical staff suggested that all 

employees were examined at one time but no records were found to validate the verbal 

communication or to add information for the site profile regarding specific dates and duration of 

practices. Per personal communications with retired LANL workers, researchers who worked 

with animals and TB in the Health Research Laboratory were examined more frequently. 

Documentation on these frequencies was also not available during the writing of this TBD. Task 

3 will submit additional requests to LANL for reference material pertaining to these procedures. 

(2) The chest x-ray frequencies and workers, to which this applied, varied appreciably 

over time. Table 3.1 of the TBD seems to suggest that during 1964–1984, not all 

employees received annual chest x-rays. Can NIOSH/ORAU verify whether this is 

correct, and if a separate standard operating procedure (SOP) exists for this time 

period? 

Dose reconstruction is performed using the x-ray TIB. The TBD just provides additional 

information that may be useful to the DRs. This information came from personal 

communication with a retired lab x-ray technician who worked at the lab from the early 1960s 

through mid 1980s. At the time the TBD was published, LANL was unable to locate these 

procedures although the former worker did believe SOPs did exist at one time. Task 3 will 

resume the search for these types of records and, if found, will include pertinent information and 

references in the planned revision to the TBD. 

(3) After 1990, it appears that chest x-rays were given to only selected worker categories 

and at varying frequency. Does NIOSH/ORAU have any documentation, SOP, or 

policy basis to support Table 3.1, as no reference is provided in the TBD? 

Dose reconstruction is performed using the x-ray TIB. The TBD just provides additional 

information that may be useful to the DRs. Task 3 will resume the search for supporting 

documents and records and will include pertinent information and references in the planned 

revision to the TBD. 

(4) The TBD states that for chest x-rays given during the 1970s, SOPs for chest x-rays 

required both a posterior-anterior (PA) and lateral (LAT) view. The TBD says this 
 

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was consistent to protocols prior to 1960. Does NIOSH/ORAU have evidence to 

support this, or do they default to two views (PA and LAT) being used consistently 

until 1985? Does current chest radiography still include both PA and LAT views? 

Regarding the first question, information in the TBD came from personal communication with a 

retired lab x-ray technician who worked at the lab from the early 1960s through mid 1980s. At 

the time the TBD was published, LANL was unable to locate these procedures although the 

former worker does believe SOPs did exist in the past. Task 3 will resume the search for these 

types of records and, if found, will include pertinent information and references in the planned 

revision to the TBD. 

(5) In Section 3.2 of the TBD, it indicates that until 1956, all pre-employment exams 

were performed using a photofluorography (PFG) unit. In terms of annual physicals, 

it suggests a default use of PFG dose estimates if no claimant file documents that 

routine radiographs were given. This approach does not document when a PFG was 

given, in addition to radiographs. Does NIOSH plan to include PFG doses for all 

employees prior to 1956, in the absence of documentation to the contrary? 

If known, site records, procedures, actual film size, and type of exam (PFG vs. other) is preferred 

when assessing dose for a particular claim. 

A LANL report states that PFGs was used up until 1956. Per NIOSH, PFG would be assumed 

for a claim through 1956. Otherwise regular x-rays are assumed. 

(6) The TBD states in Section 3.2 that between 1957 and 1964, the beam quality of Type 

1 x-ray units was not known. It suggests that dose conversion factors (DCFs) from 

ICRP 34 is appropriate for that period. How does NIOSH/ORAU plan to assure that 

the estimated filtration of 2.5 mm Al is accurate? Given that Type II units, in use 

between 1964–1984, had added filtration of 6.75 mm Al, it stands to reason that 

earlier units may have been, likewise, heavily filtered. This will affect the DCFs 

appreciably, given a much harder beam. 

Per NIOSH and the Implementation Guide, the approach used if no information is known about 

the energy spectrum is to conservatively assume a 30–250 keV photon range. 

(7) The TBD suggests the use of the default values in Table 3.6 would be claimant 

favorable, in the absence of known examination factors. Given that LANL used 

appreciably higher filtration in its units until Type III units were utilized in 1985, this 

does not appear to be claimant favorable. Is NIOSH/ORAU going to reconsider the 

default values for PA and LAT chest exams until 1985? 

Per NIOSH procedures, if the filtration is known, then that filtration should be used. Where it is 

not known, the Implementation Guide will govern. 

(8) Section 3.3 of the TBD suggests that the periods, technique factors, and equipment 

descriptions are based upon documentation and interviews; however, no pertinent 
 

 

 

 

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references are provided. Can NIOSH/ORAU provide further evidence beyond 

(LASL 1972, LASL 1976) which would support Table 3.2 and Table 3.3 of the TBD 

in their entirety? 

Available references will be added to the revised TBD. 

(9) A major consideration, as stated in the TBD, is that the DCFs for the PFG and Type 

1 units, in use until 1964, are really default assumptions. Another factor beyond the 

filtration is the assumption of a constant source-to-image distance (SID) of 72 

inches. Does NIOSH/ORAU plan in future updates to the TBD to further document 

the justification of this assumption, as it could impact the DCFs given in Table 3.7, 

such that they are not claimant favorable? 

Yes. 

(10) Section 3.5 of the TBD states that dose reconstructors should use a value of 1.53 R 

for PFG exposures in place of LASL-specific data. NIOSH/ORAU should be 

advised that earlier recommendations were to use a value of 3.0 R, as shown as a 

default value in Table 3.6 of the TBD. Can NIOSH/ORAU clarify or fix this 

inconsistency? 

Yes, this will be clarified in the revised TBD. 

(11) The TBD discusses factors which induce error into the final dose. The TBD suggests 

an upper bound of ±51% for all errors, and recommends that +30% would be 

claimant favorable. SC&A feels that a factor of +50% is warranted. Will NIOSH 

consider the use of a factor of +50%, given the lack of substantial data, actual 

documented measurements, and surveys of the equipment? 

DRs are using the most claimant-favorable values. Task 5 and NIOSH can address this question 

further. 

Responses to SC&A Questions for the LANL Site Profile Document – Occupational 

Environmental Dose, 

ORAUT-TKBS-0010-4 

The current version of ORAUT-TKBS-0010-4 was published with asserted data gaps of 

information before 1971 to allow processing of selected LANL claims. However, this section 

was designated for a future planned revision due to these existing data gaps. Planned revisions 

will include additional information pertaining to environmental monitoring and effluent data 

collected since the publication of this TBD and any applicable information that comes from 

NIOSH responses to SC&A questions. 
 

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Questions and Responses 

(1) The TBD recognizes the need for a site-wide model to assure atmospheric doses 

from all sources are inclusive. Since it does not exist, how can NIOSH/ORAU 

assure that use of rather sparse environmental measurements, and very few source 

terms, will enable adequate overall environmental dose estimates? 

Recently released LANL documents that are associated with the LAHDRA project are being 

reviewed to determine whether additional information is available to fill gaps in the TBD for 

sampling and effluent data. However, to clarify the content of the current TBD, NIOSH offers 

the following: 

The LANL AIRNET network provides continuous air sampling at the majority 

technical areas (TAs) across the site. There are some TAs where samplers are 

absent; estimates were made for those areas based on emissions estimates. From 

these data and estimates, site wide maximum annual median intakes will be 

applied to all workers. This is a claimant-favorable assumption in that it is 

unlikely that the great majority of workers will encounter these maximum intakes 

in most work locations. 

The current TBD content will remain in place until better data become available. 

(2) The TBD, as written, fails to test the adequacy of evaluating the cumulative 

(additive) effect of numerous source terms at differing locations, which are in 

different Technical Areas (TAs). Given that the current TBD recognizes this 

weakness, when does NIOSH expect to update the TBD to correct this deficiency? 

Recently released LANL documents that are associated with the LAHDRA project are being 

reviewed to determine whether additional information is available to fill gaps in the TBD for 

sampling and effluent data. A revision to this TBD is currently being developed and will utilize 

newly acquired information. 

However to clarify the content of the current TBD, NIOSH offers the following: Air monitoring 

data do not distinguish the source of emissions, and therefore, do evaluate additive effects. 

Although the ratioing method does not address cumulative effects, the use of site-wide maximum 

intakes lessens the importance of these potential effects. The best way to examine this is through 

the following example. The site-wide maximum annual median intake in 1992, for H-3, is 

estimated to occur in TA 41, where monitors are absent. This will be the value applied for 

environmental dose for unmonitored workers. Technical Area 2 is adjacent to TA-41 and also 

emits H-3 (which is measured in air at that TA); however, the air concentration at TA-2 is lower 

than in TA-41, and thus the contribution of H-3 originating from TA-2 in TA-41 will be 

negligible. 

(3) The TBD recognizes that effluents from many TAs have not been well-reported over 

the last several decades. For example, no effluents from the Omega Reactors are 

presented (TA-2). Since this site will have appreciable releases of noble gases and 
 

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mixed fission products, how does NIOSH/ORAU intend to account for this 

deficiency, as it may appreciably impact site environmental doses to workers in all 

TAs beyond those assigned to TA-2? Has NIOSH had success in defining data for 

TA-1 during the 1940s? What is the basis for results presented in Table 4A-1? 

Recently released LANL documents that are associated with the LAHDRA project are being 

reviewed to determine whether additional information is available to fill gaps in the TBD for 

sampling and effluent data. Another source of ongoing work that may help to address these 

questions involves development of co-worker data by Task 5 that could possibly be used in some 

instances to address unaccounted doses from releases. 

(4) The TBD suggests that limited emissions data may reasonably fill gaps in the 

monitoring data in estimating dose. Without the use of a site-wide atmospheric 

model, how does NIOSH/ORAU assure that any emissions data at a different TA 

location can be reasonably translated to fill in gaps in monitoring data at different 

site locations? Given the data from different TAs represent different source terms, 

how can NIOSH justify this interpolation? 

Emissions data are only used to estimate air concentrations within the same TA. The TBD does 

not attempt to use emissions data from one TA to fill in gaps in monitoring data at a different 

TA. Recently released LANL documents that are associated with the LAHDRA project are 

being reviewed to determine whether additional information is available to fill gaps in the TBD 

for sampling and effluent data. 

(5) The TBD recognizes that LANL has not provided effluent data for the years 1945– 

1971. The TBD has relied on data derived from the LAHDRA project, yet the 

validation of that data remains in question. How does NIOSH/ORAU intend to 

validate this data against the missing effluent reports for 1945–1971? Independent 

inquiry at LANL suggests essential data as far back as 1958 does exist. Will NIOSH 

modify its results to incorporate this data? 

Effluent data back to the 1940s and 1950s were viewed as not reliable or mature enough for dose 

assessment at the time this TBD was written and approved for Task 5 use. Recently released 

LANL documents that are associated with the LAHDRA project are being reviewed to determine 

whether additional information is available to fill gaps in the TBD for sampling and effluent 

data. Another source of ongoing work involves development of co-worker data by Task 5 that 

could possibly be used in some instances to address unaccounted doses from releases. 

(6) The TBD details some of the known episodic releases, but fails to give significant 

estimates of dose, due to the 1957 fire, which released plutonium into the 

environment. How does NIOSH/ORAU intend to validate for the lack of these 

estimates and assure that workers present during the fire are assessed, considering 

this lack of dose estimate? 

The purpose of the TBD is not to provide estimates of dose, but rather offers estimates of source 

term to be used to estimate dose under Task 5 activities. Effluent data used would often include 

quantities for both routine and episodic releases and the authors recognize current gaps exist in 
 

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this information. Recently released LANL documents that are associated with the LAHDRA 

project are being reviewed to determine whether additional information is available to fill in gaps 

in the TBD for sampling and effluent data. 

(7) The TBD notes that there is a paucity of information regarding episodic releases 

resulting in potential environmental contamination of workers. Did NIOSH/ORAU 

gain access to unclassified documents detailing environmental releases of 

radioactivity, i.e., (Rogers 1977), (LANL 1992) and (DOE 1991) 

Access to Rogers (1977), LANL (1992), and DOE (1991) is available. However, these 

documents do not provide sufficient quantitative information with which to estimate releases of 

radioactive materials. Rogers (1977) gives a good historical perspective on waste disposal 

activities, sites, and some incidents potentially causing releases to the environment at 

LASL/LANL, and provides many references pertinent to air monitoring activities. These 

references were previously consulted in developing the current approach to estimating intakes. 

LANL (1992) is a RFI Work Plan for TA-49, and thus describes the extent and location of 

contamination, but does not provide quantitative information for estimating historical episodic 

releases. Air monitoring results are available for this location after 1970. DOE (1991) is the 

Tiger Team Assessment of LANL, and as such, does not provide a historical perspective on 

releases. 

DOE (U.S. Department of Energy), 1991, Tiger Team Assessment of the Los Alamos National 

Laboratory, September 23 –November, 8, 1991, Office of Environment, Safety and Health 

LANL (Los Alamos National Laboratory), 1992, TA-49 Operable Unit RFI Work Plan, MDA 

AB, Chapter 7, May 1992 

Rogers, M. A, 1977, History and Environmental Setting of LASL Near-Surface Land Disposal 

Facilities for Radioactive Wastes (Areas A, B, C, D, E, F, G, and T), LA-6848-MS, Vol. I, June 

1977. (Numerous radioactive waste site fires are described in this report, which are referenced to 

official documents) 

(8) The TBD in Section 4.2.1.1.2 concludes that worker exposures to La-140 due to 

work performed in and around Bayo Canyon is to be considered as gamma exposure 

only, with little contribution due to resuspension and inhalation. Without 

documentation as to when the number of workers who frequented Bayo Canyon, 

how will NIOSH validate that inhalation was not significant for dose reconstructions 

involving La-140? 

Lanthanum-140 has a half-life of approximately 40 hours. Thus, the great majority of dose 

received from exposure to La-140 is within a relatively short time of the detonation (within 16 

days, 99.9% of the radionuclide has decayed). Therefore, the likelihood of unmonitored workers 

frequenting Bayo Canyon within that time period after a detonation is low. The number of 

workers involved in these activities was small per personal communication with Jim Lawrence. 

Task 3 is also currently working with LANL Archives staff to validate an estimate of the number 

of workers involved in RaLa operations. 
 

 

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Kraig (1997) implemented a Gaussian model to estimate dose to offsite individuals, and found 

that the dose contributed by groundshine (i.e., external dose) was approximately 3 orders of 

magnitude higher than that from inhalation and immersion. The mechanisms of exposure at the 

Bayo Canyon site would have been similar. 

Kraig, D. H., 1997. Dose Reconstruction for Weapons Experiments involving 140La at Los 

Alamos National Laboratory, 1944–1962, Health Physics 73(4). – LMB 

(9) The TBD indicates that reported levels of Am-241 releases during the early years 

are not consistent with the reported plutonium releases. How does NIOSH/ORAU 

intend to adjust for any potential under reported Am-241 effluents? 

Per NIOSH, this question has been addressed during prior SC&A and NIOSH discussions about 

other site profiles (i.e., Hanford and RFP). Plutonium handled at LANL during these periods 

was effectively the same as that of plutonium handled at Hanford and RFP. In the early years, 

Am-241 was not an issue with regard to plutonium. 

(10) The TBD supports a “ratioing” approach to estimating airborne concentrations in 

TAs that had effluent data, yet little or no ambient monitoring data. This approach is 

based upon data derived from TA-3 and TA-21. The projected correlation coefficient for these TAs, using this method, are strong to moderate. For this to be 

used, the dose reconstructor must assume that atmospheric and dispersion conditions 

are the same in all TAs, for all years. Is NIOSH likely to reevaluate this position 

since, in many TAs with differing releases and effluent characteristics, 

environmental dose could be appreciably underestimated? 

For some TAs, there were multiple monitoring stations. For years and locations when 

monitoring data were not available, an estimate was made based on the relationship between 

source emission rate and air concentration at TA-3 and TA-21. The estimated air concentration 

based on this ratioing procedure is compared to other estimated and measured concentrations, 

and is only used if it exceeds the measured site-wide maximum annual median. This is a 

claimant-favorable approach in that it is unlikely that the great majority of workers will 

encounter these maximum intakes in most work locations 

It is a reasonable request that the applicability of this be reevaluated, probably more from the 

standpoint of differing releases and effluent characteristics, than annual average atmospheric and 

dispersion conditions, which are likely to be similar across the site. The approach should be 

refined, if necessary, to assure claimant favorability. 

Recently released LANL documents that associated with the LAHDRA project are being 

reviewed to determine whether additional information is available to fill in some of the gaps in 

the TBD for sampling and effluent data. 

(11) In Section 4.2.1.4.1, the TBD addresses pre-1971 intake assessments. In summary, 

the TBD concludes that pre-1971 intakes cannot be accurately assessed, due to 

plausible discrepancies noted in effluent data. This poses two distinct questions that 
 

 

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need to be addressed by NIOSH/ORAU: (1) does the discrepancy in effluent data 

suggest the need to reconsider the use of the “ratioing” method to estimate ambient 

air concentrations? and (2) does NIOSH/ORAU intend to offer an alternative to 

estimating pre-1971 intakes? 

Recently released LANL documents that are associated with the LAHDRA project are being 

reviewed to determine whether additional information is available to fill in some of the gaps in 

the TBD for sampling and effluent data. 

(12) Section 4.2.2 of the TBD recognizes that assessments of resuspension are an ongoing 

effort, which has not been completed. Current efforts seemingly rely on the use of a 

constant resuspension factor of 1 x 10-9/m, which is not considered appropriate over 

time. Will NIOSH/ORAU address this deficiency in future updates to the TBD and 

provide a timeframe wherein the resuspension factor issue will be more fully 

addressed? 

This subject is part of an ongoing SC&A/NIOSH discussion and should be addressed outside the 

scope of this TBD. 

(13) The TBD does not clarify the possibility that substantial ambient radiation levels 

existed in the canyons up until the mid-1970s that should be added to estimated 

worker external dose. Little data (and none before 1965) are presented to 

substantiate the estimates presented in Table 4.30. Will NIOSH/ORAU consider 

evaluating occupancy at the 100% level in all affected canyons until decontamination 

is verified, and will that amount be added to ambient airborne inhalation estimates to 

be claimant favorable? 

Recently released LANL documents that are associated with the LAHDRA project are being 

reviewed to determine whether additional information is available to fill in some of the gaps in 

the TBD for sampling and effluent data. 

(14) The most significant contributor to dose due to noble gases and mixed activation 

products occurred at TA-53. Estimates in Table 4-28 demonstrate that workers at 

those sites might have received several hundred millirem exposure during operation 

years after 1976. Can NIOSH/ORAU comment on the need to clarify that most 

environmental dose is attributable to this pathway? 

It is unlikely that workers received several hundred millirem of exposures from releases 

associated with TA-53 since most of these releases occurred through elevated exhaust stacks. It 

is true that since the mid to late-1970s the highest reported doses at the site boundary are 

attributed to TA-53 releases. 

(15) The TBD addresses uncertainty as being ±20%. In future TBD updates, will 

NIOSH/ORAU demonstrate that this figure is conservative, given that data pre-1970 

is sparse and no actual documentation of uncertainty analyses is presented? 
 

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Yes, attempts will be made to better define uncertainty values in the planned revision to the 

TBD. However, Task 5 has uncertainty values that they apply in the dose assessments. Task 5 

values are equal to or higher than those stated in the TBD. 

Responses to SC&A Questions for the LANL Site Profile Document – Occupational 

Internal Dose, ORAUT-TKBS-0010-5
 

The current version of ORAUT-TKBS-0010-5 was published with asserted data gaps of 

information to allow processing of selected LANL claims. However, this section was designated 

for a future planned revision due to these existing data gaps and the ongoing development efforts 

of the new LANL bioassay database. Planned revisions will include descriptions of the new 

LANL bioassay database, additional information pertaining to in vitro and in vivo monitoring 

since the publication of this TBD, and any applicable information that comes from NIOSH 

responses to SC&A questions. 

Questions and Responses 

(1) What type of bioassay data is LANL providing to NIOSH/ORAU? Does it include data 

from all radionuclides handled at LANL? 

LANL is currently providing only in vitro bioassay data on uranium, plutonium, americium, 

tritium and polonium. In vivo measurements are available from about the mid 1960s for 

gamma-emitting fission and activation products and plutonium and americium. In later 

years, uranium has also been added to the standard in vivo analyses. There was some 

screening done in the 1950s through 1970, but the in vivo program was not well established 

at that time. 

Some bioassay results may be available for other radionuclides handled in limited amounts, 

such as Sr-90 and Ac-227. However, these data have not been provided to date. 

When rev 0 of the TBD was issued, LANL had only submitted limited plutonium, americium 

and tritium data to NIOSH. The results are now being submitted in the form of an electronic 

database. The proposed revision of the TBD will address the format and basis of the results 

in the database. Meanwhile a detailed explanation that is appended to the file which contains 

the bioassay results for each worker is available to the dose reconstructor. 

(2) On page 25 of the internal TBD, it states that the Kanne Chamber was calibrated high by a 

factor of 10. Please explain this statement. 

A Kanne Chamber measures tritium. This was noted so that, should there be an attempt to 

correlate tritium release with hypothetical or measured environmental or occupational 

exposures for that period, the over-response would be noted and could be factored into the 

calculation if necessary. 

(3) Please explain the inconsistency between the list of incidents in the site description and that 

in the internal dosimetry TBD. 
 

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Section 5.5.2 of the TBD states these are examples of incidents. These were never intended 

to be a complete list of every incident that occurred. These were included to give some 

guidance to anyone trying to look at maximum intakes and other projected doses. Also, the 

incidents referenced in Table 5-22 are related to intakes or potential intakes. The incidents 

discussed in the site description are related to the site in general, including external and 

environmental exposures. The more complete list will be referenced in an appendix to the 

TBDs. 

(4) How will dose reconstruction be done for those individuals working at the lab in the early 

days before bioassay or before reasonable sensitivity was obtained for urine analysis 

considering that nasal swipes were used for monitored and used to determine if urine 

sampling should be done? 

Section 5.6 and 5.6.1 establish potential intakes, based on air samples, for unmonitored 

workers based on air sampling data and assumed estimates of potential intakes. Co-worker 

dose is now being assembled using the bioassay data that was recently released from LANL 

to NIOSH. The dose reconstructor may also assign missed dose based on detection levels for 

all or part of the employment periods. Intakes of radionuclides, such as plutonium are 

detectable many years after the intake because of their biological kinetics. All of these 

options are available to the dose reconstructor for monitored workers with results below the 

limit of detection, unmonitored workers, and workers that the dose reconstructor determines 

may have been inadequately monitored. Assigned claimant-favorable bounding estimates 

seem to be lacking. For example, a hypothetical intake of the plutonium for the period of 

1943 through December 31, 1946, would have resulted in a body burden of approximately 

2 nCi. This is approximately 30% of the body burden of members of the UPPU club, who 

had known and significant intakes of plutonium during that time period. 

(5) How will dose reconstruction be done for these early period unmonitored individuals? 

(Secretaries working in contaminated areas, early military workers that were unmonitored, 

in areas where only select individuals were monitored, etc.) How will the dose 

reconstruction take into account questionable air monitoring sensitivity, calibration 

uncertainties, variability of sampling methods, differences in high surface contamination 

levels throughout the work areas, and the lack of data from lung counting data for many 

workers not monitored? 

As with other sites, co-worker data is becoming available for LANL as previous discussed in 

the response to question 4. OTIBs address the use of these data and the assignment to 

various types of workers. Co-worker dose is being assembled for LANL, as stated in 

questions 4. 

Uncertainty values are incorporated into these data and the results are claimant favorable. 

Very little Am-241 is expected in LANL Pu mixtures because of the Pu-241 content of the 

original material is low. Urinalysis can assess Pu. 
 

 

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(6) What claimant-friendly factors will be used for dose reconstruction calculations for those 

individuals working in the early days under the recognized “deplorable” conditions as 

discussed in the TBD Chapter 5, pages 48–51. 

The statement in the TBD was “deplorable by present-day standards”. The state of the art of 

monitoring and engineering contamination control has improved vastly since the early days. 

Assuming that contamination was more prevalent in the working environment in the 1940s 

unmonitored workers’ dose can be reconstructed using the assumed intakes in Section 5.6. 

Tritium was not on site until 1950, at which time bioassay was available. See the comments 

in response to questions 4 and 5. 

(7) How were average airborne contamination levels derived in Table 5-20? 

The airborne concentrations reported in Table 5-20 were obtained from LANL reports. The 

reports were referenced in the TBD. This is the best available information at the time the 

TBD was written. Recently released LANL documents are being reviewed to determine 

whether additional information is available to fill gaps in the TBD for sampling and effluent 

data. If warranted, new information will be included in the planned revision to this TBD. 

(8) How will dose reconstruction be accomplished with no lung counting equipment available 

or very poor sensitivity until about 1970? Page 29 states that whole body counting was not 

fully implemented until 1970. 

As stated in question 5, lung counting is not the primary method of determining intakes of 

plutonium and uranium. Urine analysis was typically used and still is. In-grown Am-241 is 

typically determined by calculation from the assumed plutonium mixtures in used at the time 

of the intake. 

Lung counting is typically a bounding result, and not required to do dose reconstruction. 

The most claimant-favorable solubility class is used in the calculation of the POC. This has 

been discussed repeatedly in other TBD reviews. 

Fission and activation products are determined by whole body counting, not lung counting, 

since some radionuclides, such as Cs-137, do not concentrate in the lung. Very little 

bioassay, urinalysis or in vivo counting, is available prior to 1970. A revision of the TBD 

will describe these data. Note that engineering controls, respiratory protection, and air 

monitoring were the primary means of control. 

OTIB-0018 is applicable for LANL from 1948. This document provides claimant-favorable 

intakes for unmonitored workers. All LANL pre-1964 claims are on hold until fission 

products can be addressed. 
 

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(9) How can dose reconstruction be accomplished for fission products and other radioisotopes 

where the TBD, page 30, notes that many are not accounted for in the site’s exposure 

analysis of generated fission product sources? 

See response to question 8. 

(10) What other sources of accidents and incidents are going to be used? The 45 noted in the 

TBD, pages 47–48, for the years 1943–1996 cannot be realistic and page 46 notes that 

information is not available for every year of operation. 

Additional information is available and will be considered for the revision to the TBD. 

However, the TBD cannot attempt to chronicle every incident that has ever occurred, nor is it 

reasonable to expect it to do that. Incident information is made available to guide the 

development of co-worker dose and maximum assumptions of dose for overestimates and 

unmonitored individuals to expedite the dose reconstruction process and provide a claimantfavorable assessment. If accounts of a particular incident are available and are linked to a 

claimant or groups of claimants then that information will be considered in resolving claims. 

Previously discussed in response to question 3. 

(11) How can the assumption, made on page 22 for absorption type assigned for plutonium, be 

assumed for americium? Americium is chemically much more soluble and is preferentially 

excreted, so this may not be claimant friendly for cancer organs other than the lung. 

Per NIOSH, this has been addressed as part of Rocky Flats TBD review. 

(12) How can all results for all periods be listed as actual values, when results before 1980 

reported results below MDA as less-than values? 

If reviewer(s) are referring to the results in the new database, LANL is responsible for the 

results in the data base and the derivation of the results. The raw data has been used to derive 

actual values, negative and positive and zeros rather than simply <MDA. This is a much 

more correct way of interpreting the results. These data are then used to complete the dose 

assessments. 

(13) Was DAC-hour tracking done and is that information available for workers in plutonium 

work areas? 

Intake and doses were not tracked in DAC-hrs (or MPC-hours). Intakes were controlled 

according to body burden and lung burdens. 

(14) How can the TBD consider no dose from Am-214 as noted on page 19 when the in-growth 

rate for this isotope is approximately 20 ppm per month when 0.5% 241Pu? Tables 5-3, 5-4, 

5-6, and 5-7 on pages 16–20 are unclear and appear inconsistent for the 241Pu present in 

fresh plutonium mixtures. 
 

 

 

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This is incorrect that no dose from americium is considered. The dose from Am-241 is 

handled similar to the Hanford process. The tables provide a graduated approach based on 

the age of the complex. Aged americium is used as appropriate. The tables provide a way to 

calculate the amount of Am-241 at a given age and original percentage of the mixture. The 

TBD doesn’t calculate or assume the dose or absence of dose from Am-241. The TBD does 

provide tables for the amounts of americium in mixtures depending on age of the mixture. 

The IMBA program, used by the dose reconstructors, assumes the dose from the daughter 

radiations when calculating dose from Pu-241 and has an option to calculate and project the 

amount of americium which will in-grow over time post-intake. The TBD also does not 

attempt to provide specific instructions to the dose reconstructor. These instructions are 

provided by Task 5. 

Tables 5-3, 5-4 and 5-7 list the ratios by activity as the titles imply. Table 5-6 lists the ratios 

by weight. The first three tables present values for different mixtures of plutonium. These 

tables are used in other site TBDs and are typically integrated by Task 5 into spread sheets so 

that the dose reconstructor can determine the amounts of Am-241 and plutonium isotopes 

present given the intake of either Pu-239 or total plutonium-alpha. It is not clear what the 

perceived inconsistency is. 

(15) How will the dose reconstruction include the exposure from americium when the TBD 

indicates that workers participated in the americium bioassay program only if there was 

potential for exposure to pure americium? (page 22). 

Americium workers were part of an additional bioassay program and bioassay results are 

available to the DRs and used as part of the standard dose reconstruction process. 

(16) How will dose reconstruction for uranium be possible considering the inconsistency of the 

data noted on page 28 and the problems with analysis results between U-235 and U-238 

noted on pages 27 and 28? 

When the TBD was issued in 2004, no uranium data had been submitted and, therefore, the only 

information available to the TBD was that found in LANL documents. Since that time, the 

uranium data have been put into the electronic data base. Task 3 and Task 5 personnel have 

worked extensively with LANL to define the uranium data and to ensure that the dose 

reconstructor has the best information to properly interpret it. Internal guidance documents have 

been developed by Task 5, with the assistance of Task 3. The information is currently being 

refined. This refined information will be included in the revision to the TBD which is being 

developed. 

(17) What controls were in place before computers for locking Zia workers out of plutonium 

areas were used if participation in a plutonium bioassay program was not recorded within 

425 days? Were Zia data purged as stated by employees in the June 18 meeting and 

suggested by Ken Silver (Silver 2005)? 

Whether or not Zia workers were locked out of plutonium areas if they failed to submit the 

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monitoring data or termination bioassay are available, these are used; if not, co-worker or other 

standard methods, such as OTIB 002 or 0018, are used to determine missed dose. Plutonium has 

an extremely long excretion pattern so bioassay taken much later can be used to assess intakes. 

From Silver 2005: 

A specific event was described by a former worker in which "the Lab hired 

summer students to purge the medical records" of Zia employees. It is unclear 

whether dose records were purged, but the former worker thinks probably so. 

According to this former worker, the purpose was to shield the Lab from potential 

liability related to a change in the maintenance contractor from Zia to another 

company. 

The TBD (Internal Dose Section) writer has no indication that the statement concerning purged 

records is valid. (The quoted statement was excerpted from comments in Silver 2005 on external 

dosimetry not internal dose.) There is no evidence that Zia records for bioassay were purged. 

The data currently being supplied to NIOSH was generated from the bioassay databases not from 

individual records. 

However, dose reconstruction protocol involve the use of missed and co-worker dose when it is 

indicated that the worker may have been unmonitored or inadequately monitored. Statements in 

the TBD, which have carried over to DR guidance, state that there is a possibility that 

maintenance workers may not have been consistently monitored; therefore, these individuals 

would be selected for assignment of co-worker dose if dosimetry records were not present. 

How will dose reconstruction be handled for those Zia workers potentially doing maintenance 

work in plutonium areas for 425 days before being locked out by the system? 

Monitoring of workers in general has been repeatedly discussed in many TBD reviews (per 

NIOSH). Standard dose reconstruction methods will be used for measured and missed doses. 

Potential missed dose is routinely assigned in the dose reconstruction if bioassay results are 

reported as less than MDA. OTIB-0018 and OTIB-0002, co-worker data, and assigned data are 

available to the dose reconstructor and used individually or in combination as deemed 

appropriate by the DRs and NIOSH. 

(18) Are the uncertainty values reported for in-vivo and in-vitro measurements the only counting 

uncertainty? The TBD, pages 41and 42, indicates that the measurement uncertainty for invitro measurements at one standard deviation and the biovariability are listed with the 

results. How were these determined? 

The uncertainty listed as one standard deviation is a counting uncertainty only. The 

biovariability is a Bayesian statistical parameter that is used at LANL. However, this parameter 

is not part of the dose reconstruction protocol and the dose reconstructor was advised as such in 

the TBD. This parameter is no longer reported in the current data supplied to NIOSH. Per 

NIOSH, standard protocols are in place to address bioassay uncertainties. 
 

 

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(19) How can the TBD state that the OWR Facility (TA-2) not be a source of radioiodine when 

Table 2-1 gives I-131 as a radiation source? 

This was a typo discovered some time ago and reported to DRs and will be corrected in the 

upcoming revision to the TBD. 

(20) How can the statements of Section 5.3.2 starting with the third paragraph be accurate 

considering the in-growth of Am-241? The TBD does address the issue of high-fired oxides 

on page 40 where in-vitro is not capable of estimating the lung deposition. 

High-fired oxides are being addressed across the sites. This is being addressed outside this TBD; 

please refer to those discussions (e.g., Rocky Flats). 

(21) How were the values given in Table 5-24 and referred to on page 46 derived? Are they 8 hr 

time weighted averages? Were there ‘hot’ spots at the release points? Can it really be 

assumed that the individuals were wearing respiratory protection? Were the respiratory 

equipment fit-tested, or, was a protection factor just assumed? 

See previous discussion on OTIB 0018. According to the documentation that has been found, 

the values in Table 5-24 were derived from current standards for airborne radioactivity during 

the time period. These values aren’t measured values; rather they are limits for work-day 

exposures assuming respirators were not worn. The limits were based on occupational exposure 

limits and did not factor respirator protection. “Hot spot” was a term used in some of the reports 

that were reviewed. No particular definition of that term was available. Respirators were 

requested by Oppenhiemer in 1943, see the referenced telex communication. A respirator 

program has been in place since then. The technology of the respirators and the programs has 

obviously improved significantly over the years. Whether every worker was assigned or, if 

assigned, wore the respirator properly and consistently cannot be determined. That is a reason 

that the dose reconstruction routinely assigns potential missed dose based on detection levels to 

the entire employment period for workers who participated or should have participated in the 

bioassay program. 

LANL was considered a forerunner in the early development of respiratory protection equipment 

and protocols. Protection factors are not listed for respirators in the early years. Industry 

standard protection factors are assumed once these standards existed. However, according to 

NIOSH guidance no assumption of respirator use is made when evaluating airborne 

concentration levels. 

NIOSH, (2002) Internal Dose Reconstruction Implementation Guideline, Rev 0, OCAS-IG-002, 

National Institute for Occupational Safety and Health, Office of Compensation Analysis and 

Support, Cincinnati, Ohio. 

(22) What consideration is given in the dose reconstruction for chronic uptakes by workers and 

even support personnel? The TBD notes that nasal swipes were used to determine uptakes 

before urine bioassay was really perfected and dependable, and, page 46 states that “Rather 
 

 

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than preventing intakes completely, the focus of the respiratory protection program, 

especially in the early years of operation, was to not exceed allowable concentration limits.” 

Standard NIOSH methodology assumes chronic intakes and most claimant-favorable parameters, 

as stated in previous TBD reviews (per NIOSH). Potential missed dose is routinely assigned for 

the entire employment periods and is assumed to be a chronic intake of the most claimantfavorable absorption type for the type of cancer, e.g., Type S would be assumed for a lung cancer 

and Type M may be assumed for the highest non-metabolic organ used for a prostate cancer (the 

modeled organ being assigned according to OTIB-0005). While it is highly unlikely that any 

worker was routinely exposed to a chronic intake every day of their employment, this is often 

assumed in the dose reconstruction to be claimant favorable. Therefore, even if there were 

occasional acute intakes followed by periods of no intake, which is the more probable situation, 

the assumption of chronic intake over the entire period of employment is adequate to cover the 

situation. Also, co-worker dose can be assigned if additional exposures are assumed. 

Responses to SC&A Questions for the LANL Site Profile Document – Occupational 

External Dose, ORAUT-TKBS-0010-6 

(1) Page 8 states that this TBD does not currently address reconstruction of skin dose. 

However, skin dose exposures are covered in the TBD. Will skin dose reconstruction be 

covered in a revised TBD or TIB? 

ORAUT-OTIB-0017, "Interpretation of Dosimetry Data for Assignment of Shallow Dose" now 

provides guidance for skin cancer assessment. The referenced statement will be removed. 

(2) Page 12 states that the impressions of the ridges of the fingertips should be used as 

indicators of radiation exposure and should be continued (1959). Isn’t this rather an extreme 

dose indicator that would result from overexposure? 

This background information is not being used for dose reconstruction. Yes, blood counts and 

finger-tip impressions were measures taken in the early years at Manhattan Project sites as 

surveillance for effects from radiation exposure that appear extreme by modern-day standards. 

The scientists eventually realized that they were not useful indicators of radiation damage for any 

doses short of significant overexposures, and dropped the practices. 

(3) Page 12 states that as of April 1960, a large percentage (50% to 100%) of workers wore film 

badges. However, in the next sentence it states that film badges were issued “only to 

personnel who need them.” Is this a contradiction, please explain? 

The percentage of people badged varied significantly by work group, depending on the nature of 

the work performed and/or areas accessed. Badges appear to have been assigned to people 

judged to “need” them, with that fraction varying from group to group. No contradiction is 

apparent. 
 

 

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(4) Pages 12 states that as of April 1960, it was proposed that film badges be issued to all LANL 

and AEC personnel on a regular basis. Did this occur? If so, for how long? 

That proposal was not accepted. Records indicate that 100% badging was never put into 

practice. 

(5) Pages 11, 14, 15, 17, 19, and 26 present conflicting information on the period in which NTP 

was used and when NTA film took its place. Were NTP only used during 1949–1951 and 

then replaced by NTA film? Or was NTP used from 1949–1956 or 1959? 

Neutron-to-photon ratios are provided in the TBD for use in reconstructing neutron doses during 

the period when NTP and/or NTA technology was in use. 

(7) Site expert James N.P. Lawrence added further comment stating that the use of Nuclear 

Track Plates was discontinued when NTA film became available, and was not re-instituted 

in a later year. He suspects typos (or careless use of the term) in whatever documents 

indicate otherwise. The referenced text will be clarified. 

(8) Page 13, Table 6-2, provides data on the average external dose to worker at LANL from 

1944–2003. However, for twelve randomly selected years from 1974–1991, neither the total 

dose nor the number of workers monitored listed in the table agree with the values listed in 

the DOE reports for those years. The ratio of average total dose (rem) from the DOE report 

compared to the values listed in Table 6-2, Column 4, range form 1 to 5, with most being 

greater than 1. Why are the values listed in the TBD usually lower than those listed in the 

original DOE report? 

As noted in its title, the values included in Table 6-2 of the TBD represent external radiation 

doses. The values for LANL reported by DOE (such as in DOE/EH-0287P for 1990) were total 

doses, external plus internal. The numbers of workers monitored that are given in Table 6-2 

include all persons that were monitored, in accordance with modern-day reporting guidelines, 

including workers in the following categories: LANL, Johnson Controls Inc. (analogous to Zia 

Company in earlier years), visitors, subcontractors, and DOE’s Los Alamos Area Office. In 

accordance with the requirements of DOE Order 5484.1 at the time, LANL did not include 

subcontractors or visitors with zero doses in the numbers of workers reported each year. 

(9) Pages 16 states “On some rare occasions when the ‘personnel control film’ showed some 

exposure due to fallout from Nevada test operations, the ‘control’ film was evaluated and its 

exposure was subtracted from all personnel film for the period.” Why would a dose that 

workers actually received from AEC operations be subtracted from their recorded dose? 

This subtraction is not being performed by the ORAU team or presented as a recommended 

practice in the TBD. The decision to subtract (on “rare occasions”) doses from NTS fallout in 

Los Alamos from personnel film badges was made by LASL dosimetry group personnel, 

apparently so that their reported dosimeter results would reflect exposures to LASL workers 

from LASL operations. 
 

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(10) Page 17 – How much beta dose was required before it was considered that “it forms a 

significant part of the total exposure”? Could this practice have led to missed extremity 

doses? 

No quantitative criteria have been identified as those used to distinguish “significant” beta 

exposure. Yes, the practice of reporting beta exposures only when they were judged to be a 

significant part of total exposures could have resulted in under reporting of extremity doses. 

Estimation of missed doses, as described in Sections 6.5.1 and 6.5.2 of the TBD, can be based on 

the nature of the dosimeters in use, MDLs, and exchange frequencies. Missed neutron doses 

prior to 1979 are estimated based on reported photon doses, adjusted per Table 6E-3, and use of 

the applicable neutron-to-photon ratio. 

Site expert James N. P. Lawrence indicates that, in the 1949–1950 timeframe, beta exposures 

were considered ‘skin’ doses. The allowable whole body dose was 0.3 R/wk and the whole body 

plus skin dose was 0.5 rad/wk. Early film badges did not have an ‘open window’ (OW) to make 

an estimate of beta exposure, so none was made. When the film badge with an OW was put into 

use, beta doses would have been evaluated if the was a source of beta radiation where the film 

badge was used. For example, in the areas where depleted (or normal) uranium was worked, 

beta exposures would have been evaluated, if the developed film density in the OW area was 

measurably greater than under the ‘metal filter’ area. And in areas where plutonium was 

worked, there was no ‘beta radiation’ (only low energy x-rays from the plutonium), so no beta 

exposures were evaluated. In the 1949–1950 time period, using the film available at that time, 

the minimum measurable density of the developed film corresponded to about 10 mR. If the 

OW density was the minimum measurable and the ‘metal filter’ density was not different from 

developed, but unexposed film, then the whole body dose would have been recorded as 0 mR 

and the whole body plus skin dose would have been recorded as 10 millirad. 

(11) Page 20 states that between 1981 and Sept 1990 doses less than 10 mrem were reduced to 

0 mrem for the records. Is this being corrected to be claimant favorable in the dose 

reconstruction (DR) process for that time period? 

Per NIOSH, this issue has been dealt with across the nuclear weapons complex in other 

discussions. This is an issue of accounting for missed doses, which is done using standard 

missed dose procedures that have been previously discussed. 

(12) Page 24 states that the Model 7776 dosimeter was not designed to perform low-penetrating 

beta or beta/low-energy photon dosimetry. Did this result in missed low-energy doses at 

LANL during their period of use? 

Per NIOSH, this issue has been dealt with across the nuclear weapons complex in other 

discussions. This is an issue of accounting for missed doses, which is done using standard 

missed dose procedures that have been previously discussed. 

(13) From the information on Page 26, and elsewhere in this TBD, it would appear that was no 

dependable personnel neutron monitoring system for recorded dose at LANL during the 

time period of 1943–1949. Is this correct? 
 

 

 

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As previously stated, missed neutron doses prior to 1979 are estimated based on reported photon 

doses, adjusted per Table 6E-3, and use of the applicable neutron-to-photon ratio distribution as 

described in Section 6E.7. 

(14) Pages 26 and 36 state that LANL became aware of the NTA film’s under response to 

neutrons below 0.8–1.0 MeV around the late 1960s. Page 38 states that a study released in 

1978 showed that the average neutron energy field at TA-55 was approximately 200 keV 

and that explains why very little neutron dose was observed using NTA film at the facility. 

Page 41 states that a study showed that the average neutron energy field at LAMPF in 18 

locations was <100 keV and that explains why very little neutron dose was observed using 

NTA film at the facility. Page 43 states that a fission neutron energy spectrum (0.1 to 1 

MeV) is to be assumed at all LANL reactors for dose purposes. How will NIOSH/ORAU 

provide claimant-favorable neutron doses for workers when this entire spectrum is 

essentially below the practical 1-MeV detection limits of NTA film used in the workers’ 

badges? 

Was anything done by LANL to correct the under response of NTA film to neutrons less than 

1 MeV in the worker’s record of dose over the years? Will it be addressed during DR, and 

how? 

NTA film data are not being used to reconstruct neutron doses to workers. NIOSH/ORAU is 

providing neutron-to-photon ratio distributions that are based on doses measured at LANL after 

NTA film was replaced. These ratios can be used with measured photon doses to estimate 

neutron exposures to workers. 

(15) Page 26 briefly refers to NTA film being sealed in plastic to minimize fading due to high 

humidity around 1989. It was demonstrated at Mound Labs (Meyer 1994) that NTA film 

fading is significant (33% in the first week and 56% in the second week). Were any steps 

taken to correct the recorded neutron dose for the many years of records prior to 1989 when 

the recorded neutron dose must have been underestimated because of track fading? 

NTA film data are not being used to reconstruct neutron doses to workers. NIOSH/ORAU is 

providing neutron-to-photon ratio distributions that are based on doses measured at LANL after 

NTA film was replaced. These ratios can be used with measured photon doses to estimate 

neutron exposures to workers. 

Site expert James N.P. Lawrence indicates that the ‘Dosimetry Bible’ contains results of NTA 

film fading studies made during the 1950–1980 time period. Since Los Alamos is a ‘low 

humidity’ environment (different from Oak Ridge or the Marshall Islands), NTA track fading 

was never considered a significant problem for film badges issued for one month intervals. His 

recollection is that less than 10% fading was observed in the studies. No corrections were 

applied specifically for fading, since the calibration exposures were also subject to the one month 

issue period. 
 

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(16) Page 27 describes the use of the Model 8823 badge to correct for the employee-specific 

neutron correction factor to be applied to the Model 7776 badge readings used from 1980– 

1998 because of the Model 7776 shortcomings concerning energy response. Was this done 

by LANL on the worker’s dose records at that time, or does this need to be done during DR? 

These neutron correction factors were applied by LANL at the time of badge processing. 

(17) Page 29 makes a statement concerning a memorandum of 8/24/62 that refers to using Co-60 

calibration to evaluate beta, gamma, and thermal neutron exposures. How was Co-60 used 

to calibrate for thermal neutrons? 

As described in various LASL reports and memoranda (including LASL 1969; 8/24/62 and 

11/27/63 memos), in the evaluations of doses using the Cycolac badge, the thermal neutron dose 

was determined by subtracting the Co-60 exposure corresponding to the density under the more 

sensitive thermal neutron filter (Filter 20) minus the Co-60 exposure corresponding to the 

density under the less sensitive thermal neutron filter (Filter 21). Details of the method can be 

provided. 

(18) Page 29 states that a 3/5/63 memorandum concerning the Pu areas at DP West instructs them 

to divide the exposure results in R by 2 to get rem. However, later in the same paragraph it 

states that the factor of 2 for Pu and soft x-rays was abandoned in January 1963 (i.e., before 

the 3/5/63 memo came out). Can you clear up this apparent conflict? 

There is no conflict. The factor of two was used before January 1963 and discontinued in 

January 1963. The text from the 3/5/63 memorandum does not provide new instructions for 

processing of badges at DP West, rather a description of practices that had been in place for 

some time for evaluating doses using the brass-cadmium badges in plutonium areas. 

(19) Page 32 states that PuBe-238 and Cf-252 sources were used to calibrate NTA film (1990 

report). However, the NTA film was measuring primarily 10–60 MeV neutrons at LAMPF. 

How can 2–4 MeV neutron sources be used to calibrate for 10–60 MeV neutrons, except on 

a relative basis? 

While neutron energies in areas near accelerator beams were certainly higher, measurements at 

various accessible locations around LAMPF where workers were much more likely to have 

received neutron exposures indicated an average neutron energy of <100 keV at LAMPF 

(Blackstock et al. 1978; see Section 6.2.3.6.2). As shown in Table 6-21, neutron energies around 

LAMPF are assumed to be distributed as follows: <10 keV (30%), 10–100 keV (30%), 0.1– 

2 MeV (20%), and 2–20 MeV (20%). 

(20) Page 35 provides calculated errors (Table 6-12) concerning the Cycolac badge response to 

low-energy photons. Was the worker’s dose record corrected by LANL to reflect this low 

response to 20 keV photons (360% low), or will this have to be done by the DR? 

As described in Section 6E.1, to ensure that dose is appropriately attributed to the low energy 

photon or electron categories in dose reconstructions, nonpenetrating dose can be estimated as 
 

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skin dose minus (deep dose + neutron dose + tritium dose). Many plutonium workers will also 

have a glovebox correction factor applied in accordance with Task 5 methods. 

The 3/5/63 memorandum cited on Page 35 discusses errors that were expected when using the 

Cycolac badge with low energy photons (<45 keV). It states that “when significant exposures to 

soft radiation (<45 keV) are measured or anticipated, a special evaluation will be made.” Per 

James N.P. Lawrence, no changes were made to the previously recorded doses, but when these 

‘special evaluations’ were made, the ‘special evaluation’ doses were the values recorded. 

(21) Page 36, Section 6.2.3.5 is titled “Uncertainty in Beta/Photon Recorded Dose.” However, it 

only refers to Table 6-14 that list beta and photon energies and percentages. How is this a 

description of uncertainties? 

This is a carryover from early TBD 6 drafts for other sites. The title will be revised. 

(22) Page 44, Section 6.2.3.8 is titled “Uncertainty in Neutron Dose.” However, it only states that 

the measurement of neutron dose in the workplace is difficult and that NTA film under 

responds. How is this a description of uncertainties? 

This is a carryover from early TBD 6 drafts for other sites. The title will be revised. 

(23) Page 47 provides an example of a neutron dose calculation according to each neutron energy 

range. Where does the factor of 2.055 come from? 

Per NIOSH, the referenced text is illustrative of the process, but specific procedures for doing 

dose reconstructions are determined by Task 5. 

The referenced value is calculated from data in the 4th and 5th columns of Table 6-20; more 

specifically, it is based on the estimated value from column 5 representative of the <10–100 keV 

neutron energy range divided by the estimated value for that same energy range from Column 4. 

Some estimation of appropriate values from Columns 4 and 5 is necessary because the energy 

range does not cleanly coincide with single values of average quality factor and neutron 

weighting factor in Table 6-20 as is the case for the other two energy groupings in the example 

calculation. 

(24) Page 48, Table 6-22, and Page 71, Table 6E-9, provide minimum and maximum values for 

neutron-to-gamma ratios for several different work areas at LANL. How will the DR know 

what value to use within the wide ranges listed? 

The TBD has been revised to specify median and 95th percentile values for recommended 

distributions of neutron-to-photon doses. These are the parameters that were requested by Task 

5 personnel. 

(25) Pages 49 and 50 provide information concerning calculating missed neutron doses from 

1951–present. What will be done in the DR process to account for neutron exposures during 

1943–1950 when adequate personnel neutron monitors were not available? 
 

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Per NIOSH, the referenced text is illustrative of the process, but specific procedures for doing 

dose reconstructions are determined by Task 5. 

Estimates of missed neutron doses from 1943 to 1951 can be based on reported photon doses, 

adjusted per Table 6E-3, and use of the applicable neutron-to-photon ratio distribution. 

(26) Page 64, third bullet point, lists nonpenetrating doses as not including the tritium dose (and 

again on Page 69). Is this tritium dose from bioassay measured internal tritium dose or 

external emersion tritium dose? 

This is the tritium dose from the bioassay program. 

(27) Pages 65 and 66 provide the statistics on gamma doses and recommends that the DR use the 

median gamma dose for unmonitored workers. The median dose is the smallest of the doses 

listed. Is this NIOSH policy and is it claimant favorable? 

Per NIOSH, the referenced text is illustrative of the process, but specific procedures for doing 

dose reconstructions are determined by Task 5. 

NIOSH is developing methods for use of co-worker data, and is preparing additional TIBs that 

will address evaluation of unmonitored workers. 

(28) Page 67, Table 6E-3 recommends that the reported photon doses during 1950–1962 be 

divided by a factor of 1.2. Is this not in contradiction to the statement in the middle of Page 

45 of the TBD that states “...reduction of reported doses, correction factors are not 

recommended...”? 

There is no contradiction. In some cases, there is not sufficient evidence to justify application of 

a correction factor that reduces doses. In the referenced case, there is sufficient evidence that use 

of film badges as documented resulted in doses to workers in plutonium areas being significantly 

over estimated, so a downward correction is warranted. 

(29) Page 67 provides some estimates of the standard errors involved in dosimetry at LANL. 

However, the statement is made that, for mixed beta and photon fields, the errors are larger 

than 30%. Is there any guidance for the DR on how much greater than 30%? Also, what 

neutron energy range does the stated standard error of +50% for NTA film apply to? 

Task 5 dose reconstructors have a process that uses standard assumptions when representing the 

uncertainty of external dosimetry data across the nuclear weapons complex. In general, this 

process overrides site data. NTA film data are not being used to reconstruct neutron doses to 

workers. 

(30) Page 67, Table E-4 recommends uncertainty factors for reported LANL doses. The 

uncertainty for neutron doses is listed as +8% for the Model 7776 Dosimeter. This appears 

to be a very small uncertainty considering the discussions of this model dosimeter in the rest 
 

 

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of the TBD (i.e., pages 26 and 27). Additionally, the Model 8823 uncertainty factor is listed 

at +8% also. However, this model needs to be supplemented with NTA/TED to cover the 

necessary neutron energy ranges at LAMPF. Shouldn’t a larger neutron dose uncertainty 

factor be used in the DR process, or a limited energy range for which the +8% is applicable 

be stated? 

Task 5 dose reconstructors have a process that uses standard assumptions when representing the 

uncertainty of external dosimetry data across the nuclear weapons complex. In general, this 

process overrides site data. 

General Questions on Occupational External Dose 

(1) What were the limits involving potential exposure to neutrons at facilities handling fissile 

materials that likely evolved over time at LANL relative to subcritical emissions? 

Extensive documentation exists. References can be provided. 

(2) When were workers first measured for exposures to neutrons from (alpha-neutron) 

reactions at LANL?
 

Exposures to neutrons from alpha-neutron reactions would have begun around 1945, during a 

period when neutron monitoring was not well developed. 

As previously stated, missed neutron doses prior to 1979 are estimated based on reported photon 

doses, adjusted per Table 6E-3, and use of the applicable neutron-to-photon ratio distribution as 

described in Section 6E.7. 

(3) Were there any positive whole-body counting measurements for Na-24 observed at 

LANL for reactor workers or workers handling fissile materials, as was done at Hanford? 

This question should more appropriately be posed to the authors of the internal radiation dose 

section of the TBD. 

Methods for criticality accident dose estimation (including those based on measurement of hair 

and blood-sodium activation) were developed and applied at LASL, as described in 1967 by 

Dale E. Hankins (LA-3910). 

(4) Has a method been developed to integrate nonstandard radiations (e.g., mesons, heavy 

particles) into dose reconstruction? 

Documentation of methods of this type has not been identified to date. James N.P. Lawrence 

states that never to his knowledge have such ‘non-standard’ radiations been included in recorded 

personal exposures. Mesons and heavy particles from accelerators occur in beams, and he is not 

aware of any personnel being exposed to such beams at LANL. 
 

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(5) How are criticality accidents being evaluated for both those involved and the responders? 

Criticality accidents have been evaluated as special cases by LANL personnel, and values added 

to worker dose records. 
 

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REFERENCES
 

Argall, R.S. 2004. Technical Basis Document for the Los Alamos National Laboratory – 

Occupational Internal Dose, ORAUT-TKBS-0010-5, Rev. 00. Oak Ridge Associated 

Universities, Oak Ridge, Tennessee. December 21, 2004. 

Buddenbaum, J.E. 2004. Technical Basis Document for the Los Alamos National Laboratory – 

Site Description, ORAUT-TKBS-0010-2, Rev. 00. Oak Ridge Associated Universities, Oak 

Ridge, Tennessee, May 7, 2004. 

Buddenbaum, J.E. 2005, Technical Basis Document for the Los Alamos National Laboratory – 

Introduction, ORAUT-TKBS-0010-1, Rev. 00, Oak Ridge Associated Universities, Oak Ridge, 

Tennessee, January 25, 2005. 

Cehn, J.I. and L. McDowell-Boyer 2004. Technical Basis Document for the Los Alamos 

National Laboratory – Occupational Environmental Dose, ORAUT-TKBS-0010-4, Rev. 00. Oak 

Ridge Associated Universities, Oak Ridge, Tennessee, October 8, 2004. 

DOE (U.S. Department of Energy) 1991. Tiger Team Assessment of the Los Alamos National 

Laboratory, September 23–November, 8, 1991, Office of Environment, Safety, and Health. 

Hacker, B. 1987. The Dragon’s Tail: Radiation Safety in the Manhattan Project, 1942–1946, 

University of California Press, p. 69. 

Johnson, P.G. 2004. Technical Basis Document for the Los Alamos National Laboratory – 

Occupational Medical Dose, ORAUT-TKBS-0010-3, Rev. 00, Oak Ridge Associated 

Universities, Oak Ridge, Tennessee. December 29, 2004. 

Los Alamos National Laboratory, 1992. TA-49 Operable Unit RFI Work Plan, MDA AB, 

Chapter 7, May 1992. 

Meyer, H.E., 1994. History of Personnel External Dosimetry Program at the Dayton Project 

and Mound Laboratory 1946–1993, Mound Laboratory, Miamisburg, Ohio. 

Rogers, M.A, 1977. History and Environmental Setting of LASL Near-Surface Land Disposal 

Facilities for Radioactive Wastes (Areas A, B, C, D, E, F, G, and T), LA-6848-MS, Vol. I, June 

1977. (Numerous radioactive waste site fires are described in this report, which are referenced to 

official documents). 

Silver, K. 1991. Review and Critique of the Draft NIOSH Site Profile Document for Los Alamos 

National Laboratory, East Tennessee State University, September 19, 2005. 

Widner, T.E. 2005. Technical Basis Document for the Los Alamos National Laboratory – 

Occupational External Dose, ORAUT-TKBS-0010-6, Rev. 00, Oak Ridge Associated 

Universities, Oak Ridge, Tennessee. May 10, 2005. 
 

 

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ATTACHMENT 4: SUMMARY OF CONFERENCE CALL ON SC&A 

QUESTIONS PROVIDED TO NIOSH 

Introduction 

SC&A submitted written questions to NIOSH pertaining to the LANL Site Profile on January 13, 

2006. NIOSH/ORAU provided written responses to these questions on March 14, 2006 in 

preparation from a conference call with SC&A. The questions and responses are provided in 

Attachment 3. Information provided by NIOSH/ORAU gives SC&A a more in-depth knowledge 

of the rationale for assumptions made within the TBD and the source documents that provide the 

basis for the TBD. The summaries below are not verbatim discussion, but include information 

supplemental to the written responses provided by NIOSH/ORAU. They are arranged by general 

topics since there was overlap in discussions conducted during the conference calls. The 

information provided by NIOSH/ORAU is listed under each topic. SC&A has provided 

comments towards the end of the summary. Actions items resulting from discussions in the 

conference call are listed at the bottom of each summary. 

LANL Site Description TBD Conference Call Summary 

Date:March 23, 2006 

Subject:Los Alamos National Laboratory-Site Description, ORAUT-TKBS-0010-2 

Time:1:00-3:00 pm EST 

Individuals who participated included: 

ORAU:Jack Buddenbaum, Paul Johnson, Don Stewart 

NIOSH:Sam Glover 

SC&A:Harry Pettengill, Kathryn Robertson-DeMers, Tom Bell, Joe Fitzgerald 

General Comments 

The current versions of these TBDs ORAUT-TKBS-0010-2 (Buddenbaum 2004) and ORAUTTKBS-0010-3 (Johnson 2004) were published with asserted data gaps in information to allow 

processing of selected LANL claims. Planned revisions of these documents will include 

additional information collected since the publication of this TBD and any applicable 

information that comes from NIOSH responses to SC&A questions. ORAUT-TKBS-0010-1 

(Buddenbaum 2005) will be revised as necessary to reflect revisions made to the TBDs. 

There is currently no classified version of the Technical Basis Document, nor is there a plan to 

develop a classified version. A majority of classified information has no relevance to the Site 

Description TBD. Workers involved in classified operations were badged or put on a bioassay 

program. 

Dose received at the Nevada Test Site (NTS) and Pacific Proving Grounds (PPG) is available. In 

the cases where badges were provided by another organization, this information was provided 
 

 

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back to LANL. LANL has done a verification ensuring this dose has been incorporated into the 

LANL dose record at least back to 1951. 

There are a number of Technical Information Bulletins used in support of the LANL dose 

reconstruction process. OTIB-0002 (Rollins 2004) and OTIB-0018 (Brackett and Bihl 2005) are 

used on an occasional basis. Which TIBs are applied is claim specific. 

LANL claims were on hold prior to LANL providing the recently obtained dataset of bioassay 

data. 

There are plans to locate and review the Omega notebooks referenced in the Site Description 

TBD on pages 33–34. The search is in process now. Since Omega was a common term at 

LANL, NIOSH/ORAU is expanding the search to include terms relating to the reactors and/or 

reactor areas. 

NIOSH/ORAU has reviewed Health Division reports and retrieved copies covering the years 

1947–1964. Some of these reports were only recently obtained. These reports are very general 

in nature, but provide hints to sources of exposure. Experience with the information provided in 

these reports is that they are not useful due to the lack of detail. 

There were no further discussions related to Question #1 (Introduction Questions), Questions #4, 

#5, #8, #9, #10, and #11 (General Questions), and Question #1 (Site Description) in 

Attachment 3, Responses to SC&A Questions for the LANL Site Profile Document, Introduction, 

ORAUT-TKBS-0010-1; Site Description, ORAUT-TKBS-0010-2; and Occupational Medical 

Dose, ORAUT-TKBS-0010-3. Based upon the written response no further discussion was 

necessary. 

SC&A Conference Call Comments 

There are no comments at this time. 

Action Items for NIOSH/ORAU 

(1) Provide a list of planned changes to the Site Description TBD 

(2) Provide a list of documents recently received from LANL 

(3) Provide an updated response to General Question #3 regarding dose received at test sites 

(4) Elaborate on the use of TIBs in dose reconstructions for LANL claims 

(5) Make the following reference cited in the TBD responses available to SC&A. 

U.S. Department of Energy, 1991, Tiger Team Assessment of the Los Alamos National 

Laboratory, September 23–November, 8, 1991, Office of Environment, Safety and Health. 

Action Items for SC&A 

(1) Provide NIOSH with a list of Action Items from the conference call. 
 

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LANL Occupational Medical Dose TBD Conference Call Summary 

Date: March 23, 2006 

Subject: Los Alamos National Laboratory-Occupational Medical Dose, 

ORAUT-TKBS-0010-3 

Time: 1:00–3:00 pm EST 

Individuals who participated included: 

ORAU: Jack Buddenbaum, Paul Johnson, Don Stewart 

NIOSH: Sam Glover 

SC&A: Tom Bell, Joe Fitzgerald, Harry Pettengill, Kathryn Robertson-DeMers 

General Comments 

The current versions of these TBDs ORAUT-TKBS-0010-2 (Buddenbaum 2004) and ORAUTTKBS-0010-3 (Johnson 2004) were published with asserted data gaps in information to allow 

processing of selected LANL claims. Planned revisions of these documents will include 

additional information collected since the publication of this TBD and any applicable 

information that comes from NIOSH responses to SC&A questions. ORAUT-TKBS-0010-1 

(Buddenbaum 2005) will be revised as necessary to reflect revisions made to the TBDs. 

Dose reconstructions prior to 1970 are being held up due to the continuing evaluation of 

environmental dose. Bioassay data was also provided belatedly. As dose reconstructions are 

being completed, the dose reconstructors also come up with additional questions and issues. 

Site specific information relating to the medical x-ray program will be further substantiated 

based on additional information retrieved from LANL or provided by site experts. There was 

very limited information at the time the Occupational Medical Dose TBD (Johnson 2004) was 

written. 

Medical Record Access 

The records provided by LANL include internal and external radiation records and very little 

medical information. They are not sending x-ray records that are not under LANL control. 

There are some issues associated with early LANL medical records. The Los Alamos Hospital 

was originally owned by the Army. The records were transferred to the Atomic Energy 

Commission, then to ERDA. They are physically located at the hospital which is now a private 

organization. DOL, DOE, and NIOSH are currently working with Senator Udall’s office to gain 

access to these medical records. 

Chest X-ray Frequency 

The original information gathered regarding physical exams for employees was based on 

personal communications with a retired technician. NIOSH/ORAU is currently looking for 
 

 

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additional documentation and medical records to support the personal communications. 

Additional references will be cited in the TBD. Based on personal communications to date, 

researchers who worked with animals and tuberculosis experiments in the Health Research 

Laboratory were examined more frequently than others. 

Default Assumptions 

Dose reconstruction is performed using the x-ray OTIB-0006 (Kathren and Shockley 2005). 

Where site specific information is available, the TBD will reflect this information. 

NIOSH/ORAU assumes an annual chest x-ray as a default. The dose reconstructor applies 

photofluorography (PFG) through 1956. Both a lateral and a posterior-anterior view are assumed 

when the views are unknown beyond this. X-ray dose is typically only assigned in noncompensable cases. 

NIOSH/ORAU used actual examination factors (e.g., filtration) values if there are known. 

Where they are not known, values from the Implementation Guide (NIOSH 2002a) are used. 

NIOSH/ORAU is currently trying to retrieve additional site specific records. 

The PFG exposure values recommended in the current version of the TBD were not determined 

based on the latest revision of the TIB. Revisions to the TBD will reflect the current version of 

the x-ray TIB. The TIBs offer a means to update methodology quickly. These updates are 

reflected in the dose reconstructions. 

There were no further discussions related to Question #8 listed in Attachment 3 (Occupational 

Medical Dose), Responses to SC&A Questions for the LANL Site Profile Document, 

Introduction, ORAUT-TKBS-0010-1; Site Description, ORAUT-TKBS-0010-2; and Occupational 

Medical Dose, ORAUT-TKBS-0010-3. The written answer provided was adequate to answer the 

question. 

SC&A Comments 

NIOSH/ORAU is encouraged to look into additional site specific records describing the medical 

x-ray procedures and examination programs. 

Establishment of the date for use of PFG is important especially in light of the fact that medical 

records are not available to identify use of small films. 

The uncertainty associated with x-rays should also consider errors associated with retakes and 

poor processing equipment. These are not addressed effectively in the TBD or TIB. 

Action Items for NIOSH/ORAU 

(1) Provide a list of planned changes to the Occupational Medical Dose TBD 

(2) Provide a list of documents recently received from LANL 

(3) Provide access to the records referenced in the responses to the Medical TBD questions 

(4) NIOSH/ORAU will provide clarification on when PFG is applied by dose reconstructors 
 

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Action Items for SC&A 

(1) Provide NIOSH with a list of Action Items from the conference call. 

(2) Provide a summary of the conference call discussion. 

LANL Occupational Environmental Dose TBD Conference Call Summary 

Date: March 7, 2006 

Subject: Los Alamos National Laboratory-Occupational Environmental Dose, 

ORAUT-TKBS-0010-4 

Time: 2:00–4:00 pm EST 

Individuals who participated included: 

ORAU: Jack Buddenbaum, Laura McDowell-Boyer, Don Stewart 

NIOSH: Sam Glover, 

SC&A: Harry Pettengill, Kathryn Robertson-DeMers 

LANL: Jim Lawrence 

General Discussion 

The current version of ORAUT-TKBS-0010-4 (Cehn and McDowell-Boyer 2004) was published 

with asserted data gaps of information before 1971 to allow processing of selected LANL claims. 

However, this section was designated for a future planned revision due to these existing data 

gaps. Planned revisions will include additional information pertaining to environmental 

monitoring and effluent data collected since the publication of the TBD and any applicable 

information that comes from NIOSH responses to SC&A questions. 

Records collected as part of the LAHDRA project have provided valuable information. The 

early efforts of the LAHDRA project were begun in 1999. This project included an extensive 

effort to evaluate records primarily pertinent to environmental dose reconstruction. In 2003, the 

project was shutdown due to lack of resources. As a result many of the records requested were 

tied up in review by the site. The project was restarted in February 2005. These records 

previously recovered are now starting to trickle out of Los Alamos. Not all data are relevant to 

the NIOSH Dose Reconstruction task. This information needs to be reviewed and its relevance 

or appropriateness for the TBD determined. This revision to the TBD will not occur until this 

data has been reviewed. 

Site-wide Model 

Unlike other sites, LANL has not developed a site-wide model for environmental dose. Effluent 

and sampling data are available in the recently retrieved data. Earlier data may not be reliable 

and must be verified. LANL AIRNET provides air sampling data for some technical areas. The 

air samplers have been added, shutdown, and changed. For some technical areas we can’t find 

data. 
 

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Cumulative (additive) Effect of Numerous Source Terms 

The air samples provide a cumulative value and will reflect all releases from the immediate area. 

The median dose at each location (i.e., TA) throughout the site is determined from these data. 

The maximum value of these medians is used as the maximum dose. Doses are assigned by 

radionuclide. This is the value assigned to workers. The median doses were obtained (or 

calculated) from LANL reports for each TA. The reports provide the average value calculated 

for all air samples collected monthly at the particular sampling location. 

Accounting for the Deficiency or Absence of Effluents Data from All TAs 

The TBD was written with the data available at the time. NIOSH/ORAU hope to fill gaps with 

the data retrieved. This data does not necessarily include effluent and airborne data from Omega 

West Reactor. In the absence of data, the gaps are addressed using bounding parameters. Argon 

effluent data for TA-2 is available. The site-wide maximum value is applied in cases where 

there is a deficiency or absences of effluent data. There was no appreciable release from the 

Omega West Reactor. The Omega West Reactor was a single boiling, water cooled, reactor with 

sealed elements. 

Pre-1971 Effluent Data 

The new information recently retrieved has some pre-1971 data; however, there is little 

confidence in the effluent data at this time. A further evaluation is required. Any data would 

have to be validated with supporting documents. The use of maximum release rates is not a good 

reflection of release in individual technical units. NIOSH/ORAU will be looking at release by 

year and determining if any gaps can be filled. 

Episodic Releases 

NIOSH/ORAU has access to unclassified documentation detailing environmental releases of 

radioactivity (Rogers 1977; LANL 1992; and DOE 1991). These references have been 

consulted. Effluent data used as a basis for the TBD often include both episodic and routine 

releases. There is no significant source data for episodic releases from burning or hydrotesting. 

Assignment of Dose Where Gaps Exist 

In lieu of environmental data, co-worker data can be used. Also, in the absence of data, coworker dose can be used. We have data for plutonium, uranium, tritium and limited fission 

product data. For internal dose we can apply OTIB-0002 (Rollins 2004) and OTIB-0018 

(Brackett and Bihl 2005). The dose reconstructor choices the method and justifies it in the dose 

reconstruction. This is a clear overestimate and is applied in likely non-compensable claims. 

RaLa Project 

Inhalation from resuspension of soil was not an issue with the RaLa project. Following the 

detonations at the RaLa Project, only a few individuals were sent in immediately to put out the 
 

 

 

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brush fires (i.e., firemen and Radiation Monitors). The explosion cloud passage was required 

before re-entry into the area. This was about 30–60 minutes post explosion. There was no air 

sampling done during these events. Small amounts of material could cause beta burns and did 

with some chemists during the separation process. 

There wasn’t a large population of workers associated with this project. There is not much 

likelihood of unmonitored workers being exposed. Co-worker dose can be assigned to a 

claimant, if necessary. 

A Gaussian Model (CAP 88) has been used to estimate dose to offsite individuals. The external 

dose contributed from groundshine was three orders of magnitude higher then immersion and 

inhalation. 

Adjustment of Any Potential Under-Reported Am-241 Effluents. 

The plutonium used during this period of time was short irradiated plutonium. As a result there 

was very little Pu-241 impurity in the plutonium and thus not much Am-241. 

Reevaluation of “Ratioing” Approach 

The ratioing method is used only when data are not available for a particular TA. It uses the 

source emission rates and the air concentrations from TA-3 and TA-21. The estimated air 

concentration using this method is compared to the maximum site-wide median value. If the 

ratioing method value is higher, it will be used instead of the site-wide maximum. The 

NIOSH/ORAU team hopes new documents will fill in some of the gaps. 

Deficiency in Resuspension Factor of 1 x 10-9/m 

The justification for a 1 x 10-9/m resuspension factor has come up in other TBD reviews and is 

being addressed generally. 

Ambient Radiation Levels in the Canyons 

There are no data to track where an individual was and when. The occupancy factor is assumed 

to be 24 hours a day, 7 days a week for the early years. In general, onsite ambient dose would 

not be a factor. There is only sparse data prior to the 1970s. No systematic air sampling 

program was in place during this era. 

Dose from Noble Gases and Mixed Activation Products from TA-53 

NIOSH/ORAU had no additional information to add regarding this. SC&A indicated there may 

be follow-up questions. 
 

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Uncertainty Analyses of ±20%. 

The 20% uncertainty in the TBD does not include all uncertainties applied to the dose 

reconstruction. 

SC&A Comments 

Based on the information provided in the conference call and the recent retrieval of additional 

data by NIOSH/ORAU, SC&A may have further questions which will be referred to NIOSH if 

necessary. 

Action Items for NIOSH/ORAU 

(1) Provide a list of planned changes to the Occupational Environmental Dose TBD 

(2) Provide a list of documents recently received from LANL 

Action Items for SC&A 

(3) Provide NIOSH with a list of Action Items from the conference call. 

(4) Provide a summary of the conference call discussion. 
 

 

 

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LANL Occupational Internal Dose TBD Conference Call Summary 

Date: March 7, 2006 

Subject: Los Alamos National Laboratory-Occupational Internal Dose, 

ORAUT-TKBS-0010-5 

Time: 10:00–12:00 pm EST 

Individuals who participated included: 

ORAU: Jack Buddenbaum, Don Stewart, Rowena Argala 

NIOSH: Sam Glover, 

SC&A: Bob Bistline, Kathryn Robertson-DeMers 

LANL: Jim Lawrence 

General Discussion 

The current version of ORAUT-TKBS-0010-5 (Argall 2004) was published with asserted data 

gaps of information to allow processing of selected LANL claims. However, this section was 

designated for a future planned revision due to these existing data gaps and the ongoing 

development efforts of the new LANL bioassay database. Planned revisions will include 

descriptions of the new LANL bioassay database, additional information pertaining to in-vitro 

and in-vivo monitoring since the publication of this TBD, and any applicable information that 

comes from NIOSH responses to SC&A questions. 

NIOSH/ORAU has received an updated database with additional bioassay information not 

previously provided by LANL. As a result, NIOSH/ORAU is working on a revision to integrate 

the new bioassay data. This is not expected to be complete for a couple of months. The revision 

will integrate the new bioassay database, clarify the uranium MDA, provide more air sampling 

data, and integrate information from additional sources including information from classified 

document review. Clarifications related to comments from Ken Silver’s report will be 

incorporated. In the interim, some issues could be addressed with page changes. 

Much of the additional data has come from data retrieval efforts for the LAHDRA program. 

This material has been undergoing classification reviews for the last two years. The additional 

documentation will not be available for SC&A review for a couple of months. The Center for 

Disease Control website has a database of LAHDRA documents. 

Dose Reconstruction for Sr-90, Ac-227, and Other Unusual Radionuclides 

Am-241 and Pu-238 bioassay results are readily available in the database. Isotopic plutonium 

analysis was available from the time that pure Pu-238 would have been present on site. As 

stated, Am-241 urine bioassay was only performed when exposure to pure Am-241 was 

suspected. These two nuclides are not in question. Ac-227 is the one special radionuclide in 

question and possibly Np-237. During the decommissioning of TA-21, Building 153, Ac-227 

was identified in the characterization. There was some chemistry work with americium and 

neptunium at the lab. There has also been work with Pu-238. 
 

 

 

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Sr-90 can be an impurity associated with the RaLa project. There would have been a limited 

amount of strontium activity collectively over the entire period of the RaLa program. This is a 

small quantity. The primary hazard related to this project was external exposure. There is no 

bioassay data available for this project. 

The data for unusual radionuclides is not easily accessible. There is some data available in 

logbook. Retrieval of these individual specific results from these logbooks is not planned since 

there is only limited data for these radionuclides. The population likely to be exposed would be 

those operators handling the material. NIOSH/ORAU relies on the CATI interview process for 

identification of other radionuclides. You cannot rely on these data being provided in the 

information provided by LANL. There are not pointers for exposures to other radionuclides in 

the records other than those possibly mentioned in the medical records. Information may be in 

the individual’s medical record, if they were involved in an incident that required medical 

attention. 

Co-worker Dose Assignment 

The procedure for assignment of co-worker data is the responsibility of Task 5. The co-worker 

questions should be addressed with Stu Hinnefeld. 

The LANL site database is not used by the dose reconstructors. This is primarily used for 

determining co-worker dose. 

As with other sites, co-worker data is becoming available for LANL as previous discussed in the 

response to question 4. OTIBs address the use of these data and the assignment to various types 

of workers. Co-worker dose is being assembled for LANL, as stated in #4 of Attachment 3, 

Responses to SC&A Questions for the LANL Site Profile Document – Occupational Internal 

Dose, ORAUT-TKBS-0010-5. Uncertainty values are incorporated into these data and the 

results are claimant favorable. 

The procedure for assignment of co-worker data is the responsibility of Task 5. The co-worker 

questions should be addressed with Stu Hinnefeld. The TBD states that there may have been 

individuals who were not monitored or were not adequately monitored, especially in the early 

years. The unmonitored worker scenario for early years (1940s) uses either average annual air 

concentration results or airborne limits. Additional information is helpful in order to be able to 

adjust doses downward when it is available. 

Air Concentration Data 

The unmonitored worker scenario for pre-1947 years is derived from air sampling results and 

limits. A hypothetical intake for this period would equate to about 30% of the Maximum 

Permissible Body Burden or the average of the intakes received by the UPPU Club Members, 

who had known and significant intakes of plutonium during that time period. 

The following statement was made on page 51 of the TBD (Argall 2004): 
 

 

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No bioassay data, except plutonium and americium urine and fecal analysis, have 

been submitted to date. Therefore, the experiences of workers with monitored 

intakes cannot be used to develop a scenario for workers who were not 

monitored. Potential intakes will be derived from removable contamination 

levels, tolerance and MAC air concentration levels, and airborne concentrations 

of significant radionuclides. 

When the TBD was written, information on other significant radionuclides, such as uranium, was 

not available. Now that data have been submitted in the form of the new database, bioassay data 

are now available to permit the development of scenarios for workers who were not monitored. 

Co-worker doses can be and are being calculated. The statement above does not reflect the 

additional data received since the issuance of the TBD. 

The average airborne levels derived in Table 5-20 in the internal dose TBD were taken directly 

from LANL reports. No procedures have been located explaining the exact method used to 

calculate these results. 

Claims for Energy Employees hired prior to 1964 are being held for dose reconstruction in the 

future. 

Plutonium and Americium 

Since americium and plutonium are linked inside a matrix, NIOSH/ORAU does not have to deal 

with the bioassay differential. In the case of either Type S or Type M material, they are 

chemically bound and will leave the body together. They also stay together when deposited in 

the lung. When it reaches the systemic organs, then americium and plutonium may have a 

differential excretion rate. This has been addressed as part of the Rocky Flats TBD (Furman and 

Lopez 2004) review. 

Tenneman’s chemistry group handled pure Am-241. Individuals involved were monitored. 

Today there are approximately 100 individuals monitored for Am-241. Am-241 was never an 

issue in the context of plutonium processing. There was no monitoring for Am-241 in the early 

days. In later years, there were specific processes that handled Am-241. The individuals 

assigned to this work were monitored. Today the Am-241 bioassay monitoring program includes 

about 100 individuals. 

The TBD does consider dose from Am-241as a contaminant in the plutonium process. The dose 

reconstructor assumes the most claimant-favorable plutonium mixture. Fresh weapons-grade 

may be assumed for a person working with plutonium extractions. Aged weapons-grade may be 

assumed for a person working with decommissioning or other places where aged might be 

assumed. These assumptions would be best estimates. For overestimates, 10-year aged fuel 

grade is usually the most claimant favorable and would be assumed even though this is not the 

mixture normally handled at LANL. There is no in-vivo count data for the earlier years. The 

plutonium received at LANL in the early years was from short run fuel so there was less of a 

buildup of Pu-241. Until May 1945, there were only microgram quantities of plutonium onsite. 
 

 

 

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This has been chronicled in the TBD and its references. For those monitored for Am-241, 

bioassay data is used. 

High-fired Oxides 

The issue of high-fired plutonium oxides is being addressed in the Rocky Flats (SC&A 2005) 

review. The methodology developed will apply to facilities complex wide. 

Bioassay Uncertainties 

The uncertainties associated with the in vivo and in vitro measurements represent counting 

uncertainties. The dose reconstructor also applies additional uncertainties during the 

reconstruction process. 

Missed Dose 

OTIB-0002 (Rollins 2004) and OTIB-0018 (Brackett and Bihl 2005) are used in maximizing 

cases. They overestimate the dose to a worker. The OTIB-0018 values were actually generated 

based on LANL data. OTIB-0002 is used infrequently and is not used for lung cancer cases. 

Locking Zia Workers Out of Plutonium Areas 

There was not a program that locked Zia workers out of the plutonium areas if participation in a 

plutonium bioassay program was not recorded within 425 days. The term “locked-out” is 

incorrect. Individuals were escorted out of the area. 

Locking Zia Workers Out of Plutonium Areas 

 “Locked out” is a computer term, meaning access is denied. It has nothing to do with physical 

locks and keys. If it was noted that they were not participating in the bioassay program, they 

wouldn’t be granted access. It appears that the program may have been written and documented 

in the referenced paper but never fully implemented. The issue will be clarified in the revision of 

the TBD. 

Retrieval and Submittal of Incident Records to NIOSH/ORAU 

Many of the incidents occurring at LANL are already provided in the TBD. Some incident 

reports are available from the medical files. The dose reconstructor does not typically have 

access to incident information from the claimant files unless it is available in the medical or work 

history file. We have discussed this with Medical Department personnel, but we are not allowed 

free access to their medical records. There is also a comment field in the database provided by 

LANL that indicates an incident occurred. Although the comment field will indicate that an 

incident occurred, it will not provide details. Incidents listed in the TBD cannot be connected 

directly to an individual. 
 

 

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Incident reports are available starting in the 1940s. In 1980, Jim Lawrence put together a file of 

hardcopy Health Physics incidents from various reports and correspondence. Many of the 

incident reports from 1943–1965 are in the form of memorandum. The collection includes 

accident and incident reports from facilities site-wide. The TBD authors reviewed the incident 

files and copies were made of relevant incidents. In addition, the LAHDRA documents were 

checked for incident reports. Incident reports include an event description, the names of 

individuals involved, the date and time of the incident, the name of the technician, and whether a 

follow-up bioassay was collected. These reports do not typically include the results of bioassay, 

and are useful only for general information and possibly development of highest dose scenarios. 

Many of the early incident reports were initially classified. There were a lot of incidents that 

were not reported. 

From a dose reconstructor’s view, incident reports are not necessary. A constant chronic intake 

from the start date of employment is often assumed, used in many cases, and exceeds the dose 

that would be calculated as a result of an incident. If an incident report is provided, that this will 

allow the dose reconstructor to fix the date of intake and determine the nature of the exposure 

when the probability of causation (POCs) near 50%. 

Data Purging 

The allegations of data purging do not affect the dose reconstruction process. A chronic intake 

from the start date of employment is often assumed. The dose reconstructor uses positive 

bioassay results to assess the dose and MDA results to assess missed dose. The doses are 

compared and the most claimant-favorable annual doses are assigned. Results are consistently 

found in Zia worker files. There is no indication of missing data. 

Unmonitored Military Personnel 

Dose for military personnel is not covered under this program. There is a separate program for 

these individuals. 

SC&A Conference Call Comments 

• 	 SC&A will review the complex wide methodology developed to address high-fired 

plutonium oxide as it relates to the LANL TBD. 

• 	 NIOSH/ORAU indicated that in the case of Type S or Type M material, americium and 

plutonium are chemically bound, and will leave the body together. The internal TBD 

(Argall 2004, pp. 20–21) contradicts this statement by indicating the plutonium-toamericium ratio in urine will differ from that of the material inhaled. Consideration 

should be given to the preferential excretion of americium not only in high-fired oxides, 

but also in more soluble forms of americium. 

• 	 The Am-241 activity values in plutonium are provided in Tables 5-3, 5-4 and 5-7. The 

percentage of Pu-241 in Table 5-6 is the same as Rocky Flats for weapons grade Pu, 
 

 

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which grows in Am-241 at a rate of ~20 ppm per month. At one year the Am-241 will be 

around 300 ppm and over 500 ppm at 2 years. For individuals working with higher 

Pu-240 mixtures, the default values may underestimate the dose. 

There were no further discussions related to Questions #2, #16, #19, and #21 listed in 

Attachment 3, Responses to SC&A Questions for the LANL Site Profile Document – 

Occupational Internal Dose, ORAUT-TKBS-0010-5. The written answer provided was adequate 

to answer the question. 

Action Items for NIOSH/ORAU 

(1) Provide a list of planned changes to the Occupational Internal Dose TBD 

(2) Provide a list of documents recently received from LANL 

(3) Explanation of when the dose reconstructor uses OTIB-0018 verses OTIB-0002 

(4) The location of the LANL Database containing bioassay for the LANL population. 

Action Items for SC&A 

(1) Provide NIOSH with a list of Action Items from the conference call. 

(2) Provide a summary of the conference call discussion. 
 

 

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LANL Occupational External Dose TBD Conference Call Summary 

Date: March 21, 2006 

Subject: Los Alamos National Laboratory-Occupational External Dose, 

ORAUT-TKBS-0010-6 

Time: 12:00 pm – 2:00 pm EST 

Individuals who participated included: 

ORAU: Jack Buddenbaum, Tom Widner (TBD Author), Don Stewart 

NIOSH: Sam Glover, 

SC&A: Ron Buchanan, Kathryn Robertson-DeMers, Tom Bell, Joe Fitzgerald 

LANL: Jim Lawrence 

General Comments 

Since January 2005, approximately 900 new documents have been screened and provided to the 

LAHDRA project. The LANL TBD team has access to these documents. Nine additional boxes 

of LAHDRA documents are currently being processed. These documents may or may not be 

relevant to external dose reconstruction, and are currently being reviewed for their relevance to 

the NIOSH dose reconstruction process. The LANL external dosimetry technical basis 

document will undergo revision following receipt of comments from S. Cohen and Associates 

(SC&A, Inc.) and review of applicable records identified in the LAHDRA documents recently 

received from LANL. The revision will incorporate recommendations from Ken Silver and 

SC&A. NIOSH/ORAU does not plan on sending specific responses to recommendations 

provided by Ken Silver. Although the Occupational External Dose TBD (Widner 2004) has not 

formally undergone revision, some of the methodologies to be implemented in the revision have 

been passed onto the dose reconstructors. 

A large number of skin cancers are compensable. There are few situations were extremity dose 

reconstructions are necessary. 

The revision of TBDs from other sites may affect the revisions made to the LANL TBDs. For 

example, changes in the SRS TBD (Scalsky 2005), will impact those in the LANL TBD. 

External Monitoring 

In the 1940s and 1950s, if individuals were working directly with radioactive material, a film 

badge was issued. The external monitoring program covered the individuals who received the 

dose. The LANL badging criteria was comprehensive enough to cover those exposed, as well as 

those who were not exposed. Support workers would have been included in the badged 

population. NIOSH/ORAU uses the recorded dose in dose reconstructions including cases 

where ionization chambers were used as dosimeters. 
 

 

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In the 1940s, film was not well known for its effectiveness in monitoring radiation exposure. 

The reactors at LANL were used for critical mass determinations and neutron sources, and later 

testing of various reactor designs. The first film badges at LANL were used in the reactors. 

Monitoring was added for those individuals involved in refining and concentrating product. The 

detection limit of 10 mrem was not conceivable until around 1953. Prior to this time, radiation 

safety personnel were looking for beta burn type affects to determine high exposures. LANL 

was not able to measure extremity dose prior to 1952. 

Nuclear Track Plates were used at LANL starting in about 1948. The function of these plates 

was to make physics measurements. In about 1949, the Nuclear Track Plates were attached to 

the badge. This system provided a crude process by which to measure exposure. Doses assigned 

from this monitoring system were recorded in the dose of record regardless of the quality of the 

measurement. 

Individuals working with neutron sources (PuBe, PoBe, etc.) and accelerator operations 

personnel were the first set of individuals monitored. Initially, reactor workers were not 

monitored for neutron exposure. 

Finger print changes were used to monitor large beta exposures prior to 1951. In 1951, the use 

of finger ridge impressions was discontinued because it was determined that they were not a 

good indicator of radiation exposure. Skin dose is assigned by the methodology outlined in 

OTIB-0017 (Merwin 2005). 

Neutron Dose 

The revisions to the TBD use neutron-to-photon ratios rather than NTP and NTA results to 

determine neutron dose. This methodology is currently built into the dose reconstruction 

process. Both a median and a 95% value are available for application by the dose reconstructor. 

The neutron-to-photon ratios determined from 1979–2000 will be used to reconstruct neutron 

dose back to 1942. NIOSH/ORAU feel the neutron-to-photon ratios provide the best data 

available. At the moment, there is some uncertainty in how to verify that the 1979–2000 data is 

representative of the early years. The photon measurements also represent the best available 

technology at the time. There were a lot of studies conducted on these badges, and the lab had a 

good idea of how these badges responded. 

For the LANSCE facility, a combination of data from TLDs and NTA film data is available. The 

dose reconstructor would combine the results from both dosimeters to obtain the dose. After 

1979, this would be used in lieu of the neutron-to-photon ratios. 

Neutron correction factors were applied by LANL at the time of badge processing, and are 

reflected in the dosimetry records. 
 

 

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Uncertainty Factor 

The +8% uncertainty factor for the Model 7776 and 8823 dosimeters comes from DOELAP 

studies of the badge systems. Additional uncertainty is built into the dose reconstruction beyond 

the +8% uncertainty factor. 

Tritium Dose 

The tritium dose was determined from bioassay data, but is included with external dosimetry. 

Individual dose components (e.g., tritium, neutron, photon) are available in the dosimetry 

records. 

Co-worker Dose 

Specific co-worker dose procedures for dose reconstruction are determined by Task 5. Coworker doses are under evaluation and will be ready by about May 2006 for LANL. There are 

generic methods covered OTIB-0020 (Merwin 2004 - external) and OTIB-0019 (Brackett 2004 - 

bioassay). 

Records 

Senator Udall’s office is currently involved in an investigation of the accuracy of medical 

records. His office has contacted NIOSH about the medical records stored at the Los Alamos 

hospital. NIOSH is currently trying to determine how the absence of these records will affect 

dose reconstruction. 

It appears that pocket ionization chamber (PIC) data was not extracted from medical records to 

dosimetry notebooks, files, or databases, but further confirmation of this should be obtained from 

LANL. If the PIC data were available, it is noted that these dosimeters were fragile and prone to 

discharge upon impact and represent unreliable data for dose reconstruction. 

Incidents 

The dose record provided by Los Alamos includes documentation on doses received from 

criticality accidents, as well as other incidents. In the case of a criticality accident, the site would 

have performed a special analysis that would be considered in the dose reconstruction. There is 

no specific methodology developed for handling the criticality accidents, as there was with the 

Y-12 TBD (Ijaz and Adler 2004). Dose reconstructors have not seen cases involving major 

incidents like this to date. 

The five volumes of information on the dosimetry program (the Bible) talk about external 

dosimetry limits, but do not necessarily discuss criticality specifications. The Criticality Safety 

group was a part of the Criticality Experiment group. Although they worked collaboratively, the 

Criticality Safety requirements were generated by Criticality Safety and not Radiological 

Control. 
 

 

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In-Vivo Detection of Na-24 

The initial in-vivo counter (Humco) was not able to distinguish between radionuclides. When 

the NaI detectors were put into service, they would have been able to detect Na-24 if it were 

present. There were no significant measurements associated with Na-24 activation. 

Shortly after the SL-1 Accident in Idaho, LANL developed a Personal Neutron Activation 

Dosimeter (PNAD) with various foils. This was for the purposes of measuring exposure in an 

accident situation. There were no accidents following their implementation that required these 

dosimeters to be read. 

Offsite Exposure 

Individuals involved in radiological activities at other sites (e.g., NTS) were assigned a badge at 

that site. The results were returned to the site. The record bears out this statement. 

NIOSH/ORAU is also making records requests for LANL employees from Nevada. The 

inclusion of the dose in LANL records, and the separate consideration of dose records from 

Nevada in the dose reconstruction process may result in a double assignment of dose. 

SEC Petition 

There was an SEC petition submitted for LANL; however it did not qualify. 

There were no further discussions related to Questions #4, #6–#13, #15–#21, and #23–#27 listed 

in Attachment 3, Responses to SC&A Questions for LANL Site Profile Document – Occupational 

External Dose, ORAUT-TKBS-0010-4. The written responses and discussions covered under 

other questions were adequate to answer these questions. 

SC&A Comments 

Page 67 of TBD-6 (Widner 2005) lists the uncertainty factors as 8% for the Model 7776 and 

8823 Dosimeters. This is for a very specific DOELAP neutron energy exposure, and not an 

indication of the dosimeter’s ability to measure neutron doses to within 8% in the overall 

working environment at LANL. Limitation of these dosimeters to different neutron energy 

spectra is discussed in TBD-6, and is one of the reasons for changing from the Model 7776 to the 

8823. To provide a clearer concept of what these dosimeters were capable of, TBD-6 needs to 

indicate the narrow energy range that the 8% uncertain covers, or better yet, list a more realistic, 

wider energy range with a corresponding larger percentage of uncertain (i.e., 20% for 10 keV to 

14 MeV, or what ever is appropriate for these dosimeters). 

Action Items for NIOSH/ORAU 

(1) Provide a list of planned changes to the Occupational External Dose TBD 

(2) Provide a list of documents recently received from LANL 
 

 

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(3) Provide further substantiation for the switch from neutron dosimeters to neutronto-photon ratios 

(4) Provide access to the following document along, with addition documentation collected 

to date about critical mass studies and measurements involving the first attempts to 

temporarily create a critical mass of fissile material. 

Hacker, B. The Dragon’s Tail: Radiation Safety in the Manhattan Project, 1942–1946, 

University of California Press (1987), p. 69. 

Action Items for SC&A 

(1) Provide NIOSH with a list of Action Items from the conference call. 

(2) Provide a summary of the conference call discussion. 

(3) Clarify the question on sub-criticality experiments and indicate how this might 

affect the dose reconstruction process 

(4) Provide questions regarding the use of neutron-to-photon ratios and the data 

supporting this approach 

(5) Review OTIB-0017 (Merwin 2005) as a procedure for assigning skin dose at LANL 
 

 

 

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ATTACHMENT 5: SUPPLEMENTAL RESPONSES TO ACTION ITEMS 

FROM CONFERENCE CALLS 

During the conference call several action items were assigned to both SC&A and the 

NIOSH/ORAU team. The response to these action items has been compiled below. 

Action Items Response for NIOSH/ORAU 

During the course of the conference call, it became apparent that significant changes were under 

consideration for the LANL site profile, and that the revision to the site profile was pending the 

release of the SC&A site profile review. The NIOSH/ORAU team has provided a list of the 

proposed planned changes to the site profile to inform both SC&A and the Advisory Board of 

their plans. 

Site description summary 

(1) Provide an updated response to General Question #3 regarding dose received at 

test sites – (Refer to the attached file Attachment “Proposed Changes-LANLTBD2006”).
 

(2) Elaborate on the use of TIBs in dose reconstructions for LANL claims – (Refer to 

the attached file Attachment C “Input from Task 5 for LANL”) 

(3) Make the following reference cited in the TBD responses available to SC&A: 

U.S. Department of Energy, 1991, Tiger Team Assessment of the Los Alamos 

National Laboratory, September 23–November, 8, 1991, Office of Environment, 

Safety and Health. This report is available on the ORAUCOC terminal 

server/SRDB. 

Occupational Medical Dose TBD Conference Call Summary 

(1) Provide access to the records referenced in the responses to the Medical TBD 

questions – (Refer to the attached file Attachment C “Input from Task 5 for 

LANL”) 

(2)	 NIOSH/ORAU will provide clarification on when PFG dose is applied by dose 

reconstructors – (Refer to the attached file Attachment C “Input from Task 5 for 

LANL”) 

Occupational Internal Dose 

(1) Explanation of when the dose reconstructor uses OTIB-0018 versus OTIB-0002 – 

(Refer to the attached file Attachment C “Input from Task 5 for LANL”) 

(2)	 The location of the LANL Database containing bioassay for the LANL population 

– (Refer to the attached file Attachment C “Input from Task 5 for LANL”) 
 

 

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Occupational External Dose 

(1) Provide input from Jack Fix on the effectiveness of the early photon badges at 

LANL – awaiting reply from Jack Fix 

(2) Provide further substantiation for the switch from neutron dosimeters to neutronto-photon ratios – (Refer to the attached file Attachment A “Proposed ChangesLANL-TBD2006”). 

(3) Provide pertinent sections of the following document along with additional 

documentation collected to date regarding subcriticality experiments.
 

Hacker, B. 1987. The Dragon’s Tail: Radiation Safety in the Manhattan Project, 

1942–1946, University of California Press, pg. 69. 

This book provides an overview of early radiation safety issues encountered at LANL 

and at other MED sites, but does not offer new details that could be used for a site profile 

document, specifically the LANL site profile. No further response is planned regarding 

this book. 

The NIOSH/ORAU team indicated during the conference call that 9 nine additional boxes of 

LANL documents were received from LANL by the LAHDRA project. These documents may 

or may not be applicable to or useful for the site profile revision. The NIOSH/ORAU team has 

provided a complete list of documents (NIOSH Attachment B) found in these boxes. 

The complete list has not been provided in this review as it contains 5,198 entries. The 

documents contained in these boxes are currently under review by NIOSH/ORAU but have not 

been uploaded to the Site Research Database to date. Some of these documents include 

additional H-Division reports, process descriptions, operations logbooks, material balance sheets, 

environmental monitoring information, Health Physics monitoring data, health hazard 

summaries, and correspondence and technical reports from the H-Division. 

NIOSH Attachment A 

Proposed Changes to be Made to Los Alamos TBDs Intro and Section 2, Site Description 

(1) Changes will be made to the Introduction section of the site profile document as 

necessary to reflect changes in other site profile sections. 

(2) Addendum to the ORAU/NIOSH Response to SC&A General Question 3: The 

following statement is an addendum to the ORAU/NIOSH initial response and 

supersedes the prior response: All dosimetry results for LANL workers visiting 

other sites where dosimetry was provided by the host sites were sent to LANL and 

became part of a worker’s exposure history file. This practice was confirmed by 

Dr. James N.P. Lawrence and John Voltin during the March 2006 conference 

calls with ORAU/NIOSH project members and SC&A reviewers. Dr. Lawrence 

was a LANL health physicist who started his employment there in 1951 and 

retired in the early 1990s. John Voltin is a health physicist currently employed at 

LANL. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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(3) The error on page 29 of Section 2 will be corrected and the value will be changed 

to 0.04 R/day. 

(4) Will update Reference section to include a list of available LANL H-Division 

reports. 

Proposed Changes to be Made to Los Alamos TBD Section 3, Occupational Medical Dose 

No revisions to Section 3 are currently planned due to a lack of new reference material. NIOSH 

is currently reviewing other medical records located at the Los Alamos Hospital that may contain 

relevant information for this section. If these efforts lead to the discovery of useful information, 

then ORAU/NIOSH will notify SC&A of any planned revisions to this TBD. 

Proposed Changes to be Made to Los Alamos TBD Section 4, Occupational Environmental 

Dose 

Errors were identified through Verification and Validation efforts in three tables of the TBD. 

These errors are attributed to data transcription issues. The necessary corrections have been 

made to Tables 4-2, 4-10, and 4-15 (Refer to revised tables below). The corrected information is 

highlighted in red. 

The impact of the changes led to a lowering of estimated intakes, particularly for H-3 at TA-3. 

In no case is there a significant increase in intake. 

Table 4-2. Estimated annual average intakes of Am-241, H-3, I-131, Pu-239, Th-232, 

U-234, MFP, and P/VAP for TA-3 (Bq/yr)a
 

Year 241Am 3

Hb 131I 239Pu 232Th 234U MFPc P/VAPd 

1971 2.7E+04 1.3E+02 2.5E-02 2.3E-02 

1972 2.8E-03 4.4E+03 5.8E+01 1.2E-02 6.9E-03 

1973 6.2E-04 4.7E+03 7.4E+01 1.2E-02 3.0E-03 1.4E-02 2.5E+00 

1974 2.9E-01 3.9E-02 6.7E-02 

1975 6.4E+03 8.2E-02 3.8E-02 3.6E-02 

1976 7.7E-03 7.1E-02 8.1E-02 

1977 1.2E+05 6.5E-03 6.6E-02 9.4E-02 

1978 2.9E+04 1.1E-02 3.6E-02 7.9E-02 

1979 8.8E+05 8.9E-01 2.1E-01 5.1E-02 9.2E-02 

1980 1.3E+03 1.4E+00 1.4E-01 3.0E-02 8.3E-02 

1981 2.6E+05 8.3E-01 7.7E-03 4.6E-02 3.4E-02 

1982 5.7E+05 9.2E-01 1.5E-02 6.3E-02 1.5E-02 

1983 6.7E+05 2.7E-01 1.7E-02 3.5E-02 3.3E-03 

1984 5.2E+05 5.9E-02 2.2E-02 4.2E-02 8.1E-03 

1985 6.2E+05 1.7E-02 3.8E-02 6.7E-02 6.8E-03 

1986 3.6E+05 1.6E-02 3.8E-02 1.2E-01 9.4E-03 

1987 2.5E+05 1.3E-02 1.7E-01 4.2E-03 

1988 2.4E+06 1.0E-02 9.8E-02 5.8E-03 

1989 8.5E+04 7.6E-03 7.1E-02 7.5E-03 

1990 1.5E+05 4.2E-03 3.8E-02 7.6E-03 
 

 

 

 

 

 

 

 

 

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Table 4-2. Estimated annual average intakes of Am-241, H-3, I-131, Pu-239, Th-232, 

U-234, MFP, and P/VAP for TA-3 (Bq/yr)a
 

Year 241Am 3

Hb 131I 239Pu 232Th 234U MFPc P/VAPd 

1991 1.3E-04 2.0E+03 1.1E-04 8.2E-03 2.8E-03 

1992 2.8E-04 3.6E+03 2.2E-04 3.2E-03 1.6E-03 

1993 1.7E-03 7.1E+02 4.9E-03 1.3E-03 1.2E-03 

1994 5.2E-04 2.7E+02 2.8E-04 3.3E-03 7.5E-03 

1995 1.3E-03 8.0E+02 2.6E-04 1.8E-03 1.8E-01 4.4E+02 

1996 1.3E-04 1.7E+02 2.4E-04 3.2E-05 2.1E-03 

1997 2.2E-04 4.8E+02 2.4E-04 7.4E-05 1.5E-03 

1998 3.1E-04 3.6E+02 3.6E-05 8.2E-05 1.3E-03 3.1E+00 

1999 2.0E-04 3.6E+02 2.4E-04 4.3E-05 1.7E-03 

2000 0.0E+00 3.2E+02 2.3E-04 2.5E-05 2.7E-03 

2001 0.0E+00 4.1E+02 5.3E-05 2.7E-05 2.4E-03 

2002 1.5E-04e 3.4E+02 1.6E-04 5.0E-05 1.9E-03 

2003 1.5E-04e 3.9E+02 1.6E-04 5.0E-05 1.9E-03 

a. Calculated from estimated air concentrations in Table 4C-3, assuming an inhalation rate of 2,400 m3/yr (and 

multiplying by 3.7 × 10-2 Bq/pCi); blanks indicate no data are available for those years. 

b. 3H intake multiplied by 1.5 to account for submersion dose. 

c. MFP = mixed fission products; claimant favorable to assume all is 90Sr. 

d. P/VAP = Particulate/vapor activation products; claimant favorable to assume all is 68Ge, Class W. 

e. Estimated from average of corresponding values for 1997–2001. 

Table 4-10. Estimated annual average intakes of Am-241, H-3, I-131, 

Pu-239, U-234, and MFP for TA-21 (Bq/yr)a 

Year 241Am 3

Hb 131I 239Pu 234U MFPc 

1971 5.7E-04d 1.1E+04 2.6E-03 1.1E-02 

1972 5.7E-04d 2.0E+04e 7.5E-03 9.6E-03 

1973 5.7E-04d 2.0E+04 2.0E-03 1.4E-02 2.0E-04 

1974 5.7E-04d 2.0E+04e 2.1E-03 6.9E-03 5.7E-04 

1975 5.7E-04d 8.5E+03 1.6E-03 4.3E-03 2.8E-04 

1976 5.7E-04d 5.3E+03 6.7E-04 5.8E-03 1.1E-04 

1977 5.7E-04d 6.9E+03 1.9E-03 1.3E-02 6.4E-04 

1978 6.6E-06 6.9E+03e 2.0E-03 1.3E-02 2.0E-04 

1979 3.7E-06 5.1E+02 5.4E-04 1.1E-02 9.1E-05 

1980 1.2E-05 1.5E+03 2.8E-03 9.9E-03 8.2E-04 

1981 5.7E-06 7.5E+02 4.1E-04 5.0E-03 5.5E-04 

1982 6.8E-06 2.1E+03 5.3E-04 1.3E-02 8.5E-05 

1983 1.9E-05 2.7E+03 8.0E-05 4.3E-03 1.6E-04 

1984 5.7E-04d 1.2E+03 1.3E-04 8.9E-03 6.1E-05 

1985 5.7E-04d 2.1E+03 3.6E-05 5.8E-03 7.1E-05 

1986 5.7E-04d 2.2E+03 1.2E-04 4.8E-03 6.3E-05 

1987 5.7E-04d 6.9E+03 9.8E-05 4.8E-03 3.7E-05 

1988 5.7E-04d 5.3E+03 7.1E-05 7.2E-03 3.0E-05 

1989 5.7E-04d 2.2E+03 1.2E-04 1.1E-02 6.1E-06 

1990 5.7E-04d 1.7E+03 2.0E-04 6.7E-03 2.5E-06 

1991 0.0E+00 1.1E+03 1.7E-04 7.5E-03 5.9E-06 

1992 2.4E-04 1.2E+03 8.9E+01 2.2E-04 3.3E-03 4.7E-06 

1993 3.2E-04 5.6E+02 4.4E-04 2.4E-03 2.0E-06 

1994 5.7E-04 4.5E+02 5.9E-04 2.5E-03 9.8E-06 

1995 5.5E-04 1.1E+03 1.1E-03 2.8E-03 
 

 

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Table 4-10. Estimated annual average intakes of Am-241, H-3, I-131, 

Pu-239, U-234, and MFP for TA-21 (Bq/yr)a 

Year 241Am 3

Hb 131I 239Pu 234U MFPc 

1996 3.7E-04 4.1E+02 1.5E-03 2.2E-02 

1997 3.8E-04 6.3E+02 1.5E-03 1.9E-03 

1998 5.0E-04 1.5E+03 2.3E-03 1.4E-03 

1999 2.6E-04 8.2E+02 3.1E-04 1.9E-03 

2000 8.3E-05 9.7E+02 3.3E-04 1.8E-03 

2001 0.0E+00 9.6E+02 3.3E-04 2.3E-03 

2002 2.4E-04f 9.8E+02f 9.5E-04f 1.9E-03f 

2003 2.4E-04f 9.8E+02f 9.5E-04f 1.9E-03f 

a. Calculated from estimated air concentrations in Table 4C-12, assuming an inhalation rate of 2,400 m3/yr 

(and multiplying by 3.7 × 10-2 Bq/pCi); blanks indicate no data are available for those years. 

b. 3

H intake multiplied by 1.5 to account for submersion dose. 

c. MFP = mixed fission products; claimant favorable to assume all is 90Sr. 

d. Assumed to be the highest value of all years for which data are available. 

e. Assumed to be the highest value of the two adjacent years. 

f.	 Estimated from average of corresponding values for 1997–2001. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Table 4-15. Estimated annual average intakes of H-3, Pu-239, and 

U-234 for TA-41 (Bq/yr)a
 

Year 3Hb 239Pu 234U 

1971 9.4E+04 3.7E-03 

1972 3.2E+04 2.1E-03 

1973 1.7E+04 3.0E-04 

1974-1978 

1979 4.2E+04 

1980 1.2E+05 

1981 3.7E+04 

1982 3.8E+04 

1983 2.9E+05 

1984 1.4E+06 

1985 3.7E+05 

1986 3.9E+05 

1987 1.4E+05 

1988 5.1E+05 

1989 3.4E+06 

1990 1.3E+06 

1991 1.1E+06 

1992 8.6E+04 

1993 1.4E+05 2.0E-06 

1994 5.0E+04 3.9E-06 

1995 2.3E+04 3.0E-06 1.8E-06 

1996 3.2E+04 

1997 1.2E+04 

1998 1.1E+04 

1999 3.8E+03 

2000 1.8E+03 

2001 1.6E+05 

2002 3.7E+04c 

2003 3.7E+04c 

a. Calculated from estimated air concentrations in Table 4C-17, assuming an 

inhalation rate of 2,400 m3

/yr (and multiplying by 3.7 × 10-2 Bq/pCi); blanks 

indicate no data are available for those years. 

b. Estimated from average of corresponding values for 1997–2001. 

c. 3H intake multiplied by 1.5 to account for submersion dose. 

No other revisions to Section 4 are currently planned due to a lack of qualified data before 1971. 

Revisions to this TBD are possible in the future as release estimates for pre-1971 are refined 

under the LAHDRA project efforts. 

Proposed Changes to be Made to Los Alamos TBD Section 5, Occupational Internal Dose 

(1)	 Will add discussion on the format and content of the new LANL Bioassay Data base 

which was finalized in November 2005 and includes units, MDA values, and supporting 

information (e.g., sampling date, volume, and interpretation of results). 

(2) Will add descriptions of Delayed Neutron Activation Analysis (DNAA) and associated 

practices used by LANL for estimating uranium in bioassay samples and interpretation of 

data presented in the new LANL Bioassay Database for U-238 and U-235 when both 
 

 

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results are listed for a sample. Uranium results had not been supplied to NIOSH before 

the TBD was published and therefore descriptions of uranium analysis were not included 

in the document. The issues have been researched and the information communicated to 

the dose reconstructors. How to use results for uranium DNAA (presently referred to as 

UNAA at LANL) will be incorporated into the TBD document. 

(3)	 Will add clarification on MDA values used for the early years based on information 

provided by Margo Clark’s paper in 2005 on the history of the Bioassay program. 

(4) Will add inventory values for Barium-140/Lanthanum-140 and strontium-90 in the RaLa 

shots; hypothetical overestimates of missed intakes will be derived for workers with 

presumptive cancers potentially exposed during the RaLa project years. 

(5)	 Will add clarification of bioassay protocol for Zia workers based on discussions with Jim 

Lawrence, who directed the bioassay program from 1951 through 1992. Clarification 

will include discussions of the bioassay protocol and protocols used for restricting Zia 

workers’ access to material handling areas. 

(6) Will add clarification on the availability of ‘special nuclide’ bioassay information. No 

bioassay results for special nuclides will be available in the new database. Information 

on nuclides other than plutonium, americium, tritium, uranium, and polonium in-vitro 

bioassay and fission/activation product whole-body counts and uranium, americium, and 

plutonium lung counts will be the only data generally provided for a claimant. The 

results of any other bioassay that may have been performed for other nuclides will only 

be available upon request. 

(7) Will remove statements regarding missing 1951 uranium bioassay data. Originally 

documents from the 1990s indicated that the notebook was missing. However, review of 

the new database indicates that bioassay results are present for 1951. 

(8)	 Will develop a list of organs and the fission products that produce the highest potential 

dose to those organs. This is useful in assigning potential missed dose when whole-body 

count results are below MDA levels. This can be done on an individual basis, but this 

type of list will assist the dose reconstructor to determine the most claimant-favorable 

assignment more quickly. Estimates of missed intakes may be provided based on air 

sample results if additional results are available, and if necessary. The calculated coworker internal dose may be determined to be adequate for mixed fission products. 

(9)	 Documented intake incidences that have been identified since the TBD was released will 

be added. 

(10) Revised TBD will include general editing for enhancement and readability of the 

document. 

(11) Will remove the word “not” on page 30 concerning iodine at OWR. 
 

 

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(12) The internal co-worker doses are expected to be published soon. These doses will be 

reviewed. Following the review, the extent to which the TBD will need to be modified to 

fill in any gaps will be determined at that time. 

Proposed Changes to be Made to Los Alamos TBD Section 6, Occupational External Dose 

(1) Will add text regarding the definition of “facility” to the Section 6.1 Introduction. 

(2) Will change the photon energy group percentages for Accelerator Operations in Table 

6-14 and Table 6E-7 based on comments from Task 5 and OCAS personnel. Will 

eliminate discrepancy between Tables 6-14 and 6E-7 and add guidance concerning 

attribution of “shallow” dose to <30 keV photons and >15 keV electrons. 

(3)	 Will clarify the adjustment factors to be applied to reported photon doses (Table 6E-3) 

and the time periods and conditions under which they should be applied. 

(4)	 Will change the recommended distributions for neutron-to-photon ratio from uniform 

distributions to distributions characterized by medians and 95th percentile values, and add 

a distribution for plutonium facilities that handled Pu-238. 

(5)	 Will correct the definition of RBE, which currently yields 1/RBE. 

(6)	 Will, if so directed by ORAU Task 5/NIOSH, add a discussion concerning the 

representativeness of neutron-to-photon ratio distributions derived from 1979–2000 data 

to operations in years before 1979, and/or provide justification for use of those 

distributions to estimate neutron exposures when neutron monitoring was not performed, 

unreliable, or highly uncertain. 

(7)	 If so directed by ORAU Task 5/NIOSH, will remove the +8% uncertainty factors for the 

7776 and 8823 TLDs, or add an indication that the uncertainty factors provided in 

Table 6E-4 are not the factors ultimately used in dose reconstruction. 

(8) If clarification is provided concerning what information is desired, will add a discussion 

of external dose monitoring practices applied to workers involved in critical assembly 

experimentation and/or criticality incidents, and/or information regarding radiation fields 

that would have been expected from those activities. 

(9) Will review referenced recent revisions to the SRS TBD and, if applicable, propose 

revisions to the LANL TBD that are warranted. 
 

 

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NIOSH Attachment C 

Additional Detail from Task 5 on Los Alamos National Laboratory 

SC&A Questions 

(Don Stewart) 

Site Description Summary, Item 4. 

As SC&A points out, the use of technical information bulletins in LANL dose reconstructions 

is case-specific, and they are applied for a variety of reasons. The best resource for a given 

claim is of course the dose reconstruction report, which will cite each technical information 

bulletin used; however, for the sake of assisting resolution of the question, the following 

highlights are provided. 

 Some technical information bulletins apply guidance to all dose reconstructions equally, 

such as ORAUT-OTIB-0005, ‘Internal Dosimetry Organ, External Dosimetry Organ, and 

IREP Model Selection by ICD-9 Code,’ which lists current guidance over which cancer 

model, assumed internal organ for dose reconstruction, and assumed organ for external 

dose reconstruction are to be applied to any given ICD-9 code; 

 Some technical information bulletins apply to all cancers in a certain class, the most-used 

example being ORAUT-OTIB-0017, ‘Interpretation of Dosimetry Data for Assignment of 

Shallow Dose,’ which is used to apply the current best assumptions for estimating skin 

dose from dosimeter records; 

 Some technical information bulletins were created especially to address gaps or updates to 

information in site technical basis documents (e.g. technical information bulletin ORAUTOTIB-0027, ‘Supplementary External Dose Information for Rocky Flats Plant’), or 

incorporation of additional information published elsewhere (e.g., ORAUT-OTIB-0050, 

‘Use of Rocky Flats Neutron Dose Reconstruction Project Data in Dose Reconstructions’). 

Currently, there are no technical information bulletins in these categories for Los Alamos 

National Laboratory. 

 Co-worker doses, when available, are applied in accordance with guiding technical 

information bulletins ORAUT-OTIB-0020 ‘Use of Co-Worker Dosimetry Data for 

External Dose Assignment,’ and specific doses are provided in specific technical 

information bulletins for each site. No co-worker doses are currently published in technical 

information bulletins for Los Alamos National Laboratory. 

 Other TIBs guide dose reconstructors to perform specific tasks, such as wound modeling, 

calculating tritium doses from tritium bioassay results, etc. Many of these would be 

applicable to LANL in specific cases, as indicated in individual dose reconstruction reports. 

 Internal dose overestimates are available in ORAUT-OTIB-0014, ‘Assignment of 

Environmental Doses for Employees Not Exposed to Airborne Radionuclides in the 

Workplace,’ ORAUT-OTIB-0018, ‘Internal Dose Overestimate for Facilities with Air 

Sampling Programs,’ and ORAUT-OTIB-0002, ‘Maximum Internal Dose Estimates for 

Certain DOE Complex Claims.’ 
 

 

 

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Occupational Medical Dose, Item 3. 

Records referenced in the responses referenced in the responses to the Medical TBD questions 

include the technical basis document itself, other cited references, and the reproduction of a 

table discussing application of occupational medical x-ray doses in a dose reconstruction 

guideline for the LANL site. Since this is a convenience document that summarizes the 

technical basis document, the technical basis document itself remains the best record in this 

case. 

Occupational Medical Dose, Item 4. 

Dose reconstructors assume all routine annual occupational medical x-rays through the year 

1956 are photofluorographic exams. In light of this standard overestimating assumption, no 

decision is called for in this case by the dose reconstructor as to whether a given exam was 

photofluorographic or not, prior to 1957. 

Occupational Internal Dose, Item 3. 

 ORAUT-OTIB-0018, ‘Internal Dose Overestimate for Facilities with Air Sampling 

Programs,’ and ORAUT-OTIB-0002, ‘Maximum Internal Dose Estimates for Certain DOE 

Complex Claims,’ both provide overestimated internal dose estimates as delimited by the 

use limitations in each document. Dose reconstructors have the option to use them when 

applicable, and may even apply them in cases where they are not strictly applicable 

according to the use limitations, if this application is sufficiently justified based on case 

data and the justification for the application is documented in the dose reconstruction report 

(this is rare); 

 Typically, OTIB-0002 is applied for individuals with no internal dose monitoring or dose 

monitoring with zero or negligible results; OTIB-0002 is also limited to non-systemic 

organs per its list of applicable organs. Systemic organs are included in the applicability of 

OTIB-0018. 

 The selection of TIB-0018 is typically reserved for claims where individuals are more 

likely to have been exposed to airborne radioactivity on a routine basis. It presupposes a 

continuous exposure (over an occupational year) to airborne radioactivity at the control 

criterion, which is, as most operational health physicists will agree, an overestimating 

assumption due to the fact that typical exposures at or above the control criterion are short 

with respect to an occupational year. 

 Due to its higher internal doses, OTIB-0018 is typically used when an individual is 

suspected to have been exposed to unmonitored intakes based on work category, 

information in the interview record, or other case-specific data. 

 It should be noted that the utility of the internal dose overestimate from this OTIB-0018 is 

limited for systemic organs, as the allowable air concentrations and the resultant doses to 

systemic organs are often large, precluding their use for completing a non-compensable 

claim. 
 

 

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 Both OTIB-0002 and OTIB-0018 may be used only for non-compensable cases at the Los 

Alamos National Laboratory. 

Action Items Response Summary for SC&A 

SC&A’s summary of the conference call is documented in Attachment 4. Included in this 

summary are the action items from each of the conference calls held. This summary was shared 

with the NIOSH/ORAU Team on May 7, 2006, to obtain their feedback on the factual accuracy. 

Comments received have been integrated. 

SC&A provided questions related to the use of neutron-to-photon ratios and the data used to 

support this approach. The original TBD makes use of the neutron dosimetry results, whereas 

the planned revision will apply neutron-to-photon ratios. This marks a significant changed in 

approach that is not reflected in ORAUT-TKBS-0010-6, Rev. 0. The NIOSH/ORAU Team 

referred SC&A to ORAUT-OTIB-0017 as the approach to be used for assigning skin dose. If 

assigned by the Advisory Board, SC&A will conduct a formal review of the OTIB. 
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ATTACHMENT 6: LANL-SPONSORED ATMOSPHERIC AND UNDERWATER 

Table A6-1: Los Alamos National Laboratory Sponsored Atmospheric Weapons Tests, Underwater W

and Special Projects 

Test Operation Date Location Type 

Trinity 7/16/1945 Alamagordo, New Mexico Atmospheric Able Crossroads 6/30/1946 Bikini Island Airdrop Baker Crossroads 7/24/1946 Bikini Island Underwater 

X-ray Sandstone 4/14/1948 Enewetak Tower 

Yoke Sandstone 4/30/1948 Enewetak Tower Zebra Sandstone 5/14/1948 Enewetak Tower Able Ranger 1/27/1951 Nevada Test Site Airdrop Baker Ranger 1/28/1951 Nevada Test Site Airdrop Easy Ranger 2/1/1951 Nevada Test Site Airdrop Baker-2 Ranger 2/2/1951 Nevada Test Site Airdrop Fox Ranger 2/6/1951 Nevada Test Site Airdrop Dog Greenhouse 4/7/1951 Enewetak Tower 

Easy Greenhouse 4/20/1951 Enewetak Tower 

George Greenhouse 5/8/1951 Enewetak Tower 

Item Greenhouse 5/24/1951 Enewetak Tower 

Able Buster 10/22/1951 Nevada Test Site Tower Baker Buster 10/28/1951 Nevada Test Site Airdrop Charlie Buster 10/30/1951 Nevada Test Site Airdrop 

Dog Buster 11/1/1951 Nevada Test Site Airdrop Easy Buster 11/5/1951 Nevada Test Site Airdrop Sugar Jangle 11/19/1951 Nevada Test Site Surface Uncle Jangle 11/29/1951 Nevada Test Site Crater 

Able Tumbler-Snapper 4/1/1952 Nevada Test Site Airdrop 

Baker Tumbler-Snapper 4/15/1952 Nevada Test Site Airdrop Charlie Tumbler-Snapper 4/22/1952 Nevada Test Site Airdrop 

Dog Tumbler-Snapper 5/1/1952 Nevada Test Site Airdrop 
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Table A6-1: Los Alamos National Laboratory Sponsored Atmospheric Weapons Tests, Underwater W

Special Projects (continued) 

Test Operation Date Location Type 

Easy Tumbler-Snapper 5/7/1952 Nevada Test Site Tower Fox Tumbler-Snapper 5/25/1952 Nevada Test Site Tower 

George Tumbler-Snapper 6/1/1952 Nevada Test Site Tower How Tumbler-Snapper 6/5/1952 Nevada Test Site Tower Mike Ivy 10/31/1952 Enewetak Surface King Ivy 11/15/1952 Enewetak Airdrop Annie Upshot-Knothole 3/17/1953 Nevada Test Site Tower Nancy Upshot-Knothole 3/24/1953 Nevada Test Site Tower Dixie Upshot-Knothole 4/6/1953 Nevada Test Site Airdrop Badger Upshot-Knothole 4/18/1953 Nevada Test Site Tower Encore Upshot-Knothole 5/8/1953 Nevada Test Site Airdrop 

Harry Upshot-Knothole 5/19/1953 Nevada Test Site Tower Grable Upshot-Knothole 5/25/1953 Nevada Test Site Airburst Climax Upshot-Knothole 6/4/1953 Nevada Test Site Airdrop 

Bravo Castle 2/28/1954 Nevada Test Site Surface Union Castle 4/25/1954 Nevada Test Site Barge Yankee Castle 5/4/1954 Nevada Test Site Barge Nectar Castle 5/13/1954 Enewetak Barge Wasp Teapot 2/18/1955 Nevada Test Site Airdrop Moth Teapot 2/22/1955 Nevada Test Site Tower Hornet Teapot 3/12/1955 Nevada Test Site Tower Bee Teapot 3/22/1955 Nevada Test Site Tower 

Ess Teapot 3/23/1955 Nevada Test Site Crater 

Apple-1 Teapot 3/29/1955 Nevada Test Site Tower Wasp Prime Teapot 3/29/1955 Nevada Test Site Airdrop 

HA Teapot 4/6/1955 Nevada Test Site Airdrop 

MET Teapot 4/15/1955 Nevada Test Site Tower 

Apple-2 Teapot 5/5/1955 Nevada Test Site Tower Wigwam Wigwam 5/14/1955 Pacific Underwater 

Zucchini Teapot 5/15/1955 Nevada Test Site Tower No.1 Project 56 11/1/1955 Nevada Test Site Surface 
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Table A6-1: Los Alamos National Laboratory Sponsored Atmospheric Weapons Tests, Underwater W

Special Projects (continued) 

Test Operation Date Location Type 

No. 2, Plutonium dispersal Project 56 11/3/1955 Nevada Test Site Surface No. 3, Plutonium dispersal Project 56 11/5/1955 Nevada Test Site Surface No. 4, Plutonium dispersal Project 56 1/18/1956 Nevada Test Site Surface 

Romeo Castle 3/26/1956 Nevada Test Site Barge Lacrosse Redwing 5/4/1956 Enewetak Surface 

Cherokee Redwing 5/20/1956 Bikini Island Airdrop Erie Redwing 5/30/1956 Enewetak Tower 

Franklin Plumbbob 6/2/1956 Nevada Test Site Tower Seminole Redwing 6/6/1956 Enewetak Surface Flathead Redwing 6/11/1956 Bikini Island Barge Blackfoot Redwing 6/11/1956 Enewetak Tower 

Osage Redwing 6/16/1956 Enewetak Airdrop Dakota Redwing 6/25/1956 Bikini Island Barge Navajo Redwing 7/10/1956 Bikini Island Barge Huron Redwing 7/21/1956 Enewetak Barge No.1, Plutonium dispersal Project 57 4/24/1957 NAFR Surface Boltzmann Plumbbob 5/28/1957 Nevada Test Site Tower Priscilla Plumbbob 6/24/1957 Nevada Test Site Balloon 

Coulomb-A Plumbbob 7/1/1957 Nevada Test Site Surface John Plumbbob 7/19/1957 Nevada Test Site Rocket Kepler Plumbbob 7/24/1957 Nevada Test Site Tower Pascal-A Plumbbob 7/26/1957 Nevada Test Site Balloon 

Stokes Plumbbob 8/7/1957 Nevada Test Site Shaft Doppler Plumbbob 8/23/1957 Nevada Test Site Balloon Pascal-B Plumbbob 8/27/1957 Nevada Test Site Shaft Franklin Prime Plumbbob 8/30/1957 Nevada Test Site Balloon Galileo Plumbbob 9/2/1957 Nevada Test Site Tower Coulomb-B Plumbbob 9/6/1957 Nevada Test Site Surface Laplace Plumbbob 9/8/1957 Nevada Test Site Balloon 

Fizeau Plumbbob 9/14/1957 Nevada Test Site Tower Newton Plumbbob 9/16/1957 Nevada Test Site Balloon 
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Table A6-1: Los Alamos National Laboratory Sponsored Atmospheric Weapons Tests, Underwater W

Special Projects (continued) 

Test Operation Date Location Type 

Pascal-C Project 58 12/6/1957 Nevada Test Site Shaft Coulomb-C Project 58 12/9/1957 Nevada Test Site Surface Yucca Hardtack 1 4/28/1958 Pacific Balloon Cactus Hardtack 1 5/5/1958 Enewetak Barge 

Butternut Hardtack 1 5/11/1958 Enewetak Barge 

Koa Hardtack 1 5/12/1958 Enewetak Surface 

Wahoo Hardtack 1 5/16/1958 Enewetak Underwater 

Holly Hardtack 1 5/20/1958 Enewetak Barge Yellowwood Hardtack 1 5/26/1958 Enewetak Barge 

Magnolia Hardtack 1 5/26/1958 Enewetak Barge 

Tobacco Hardtack 1 5/30/1958 Enewetak Barge Rose Hardtack 1 6/2/1958 Enewetak Barge 

Umbrella Hardtack 1 6/8/1958 Enewetak Underwater 

Walnut Hardtack 1 6/14/1958 Enewetak Barge 

Linden Hardtack 1 6/18/1958 Enewetak Barge 

Elder Hardtack 1 6/27/1958 Enewetak Barge Sequoia Hardtack 1 7/1/1958 Enewetak Barge Scaevola Hardtack 1 7/14/1958 Enewetak Barge Pisonia Hardtack 1 7/22/1958 Enewetak Barge 

Teak Hardtack 1 8/1/1958 Johnston Island Area Rocket 

Orange Hardtack 1 8/12/1958 Johnston Island Area Rocket Argus I Argus 8/27/1958 South Atlantic Rocket 

Argus II Argus 8/30/1958 South Atlantic Rocket Argus III Argus 9/6/1958 South Atlantic Rocket 

Eddy Hardtack II 9/19/1958 Nevada Test Site Balloon Mora Hardtack II 9/29/1958 Nevada Test Site Balloon Quay Hardtack II 10/10/1958 Nevada Test Site Tower Lea Hardtack II 10/13/1958 Nevada Test Site Balloon Dona Ana Hardtack II 10/16/1958 Nevada Test Site Balloon Rio Arriba Hardtack II 10/18/1958 Nevada Test Site Tower 

Socorro Hardtack II 10/22/1958 Nevada Test Site Ballon 
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Table A6-1: Los Alamos National Laboratory Sponsored Atmospheric Weapons Tests, Underwater W

Special Projects (continued) 

Test Operation Date Location Type 

Oberon Hardtack II 10/22/1958 Nevada Test Site Tower Catron Hardtack II 10/24/1958 Nevada Test Site Tower De Baca Hardtack II 10/26/1958 Nevada Test Site Balloon Santa Fe Hardtack II 10/30/1958 Nevada Test Site Balloon 

Adobe Nougat 4/25/1962 Christmas Island Area Airdrop 

Aztec Nougat 4/26/1962 Christmas Island Area Airdrop 

Questa Nougat 5/4/1962 Christmas Island Area Airdrop 

Mesilla Nougat 5/9/1962 Christmas Island Area Airdrop 

Swordfish Nougat 5/11/1962 Pacific Underwater Encino Nougat 5/12/1962 Christmas Island Area Airdrop Nambe Nougat 5/25/1962 Christmas Island Area Airdrop Alma Nougat 6/8/1962 Christmas Island Area Airdrop 

Yeso Nougat 6/10/1962 Christmas Island Area Airdrop Rinconada Nougat 6/15/1962 Christmas Island Area Airdrop 

Dulce Nougat 6/17/1962 Christmas Island Area Airdrop Dulce Nougat 6/17/1962 Christmas Island Area Airdrop Otowi Nougat 6/22/1962 Christmas Island Area Airdrop 

Otowi Nougat 6/22/1962 Christmas Island Area Airdrop Starfish Prime Storax 7/9/1962 Johnston Island Area Rocket 

Sunset Storax 7/10/1962 Christmas Island Area Airdrop 

Small Boy Storax 7/14/1962 Nevada Test Site Tower Little Feller Storax 7/17/1962 Nevada Test Site Surface 

Chama Storax 10/18/1962 Johnston Island Area Airdrop Checkmate Storax 10/20/1962 Johnston Island Area Rocket Bluegill 3 prime Storax 10/26/1962 Johnston Island Area Rocket Kingfish Storax 11/1/1962 Johnston Island Area Rocket 

Tightrope Storax 11/4/1962 Johnston Island Area Rocket 

* Data has been compiled from United States Nuclear Tests, July 1945 through September 1992 (DOE/NV 2000). 
 

 

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ATTACHMENT 7: SUMMARY DOSE RECONSTRUCTION 

ASSUMPTIONS AND CONSISTENCY OF ASSUMPTIONS WITH OTHER 

SITE PROFILES 

The default site profile assumptions and methodologies for Los Alamos National Laboratory 

(LANL) are summarized below and were compared to those of other site profiles reviewed to 

date or in current review. LANL developed many of the initial procedures used at other DOE 

facilities to support the weapons program. Periodically, LANL served as a backup to other DOE 

sites, such as Rocky Flats Plant and Hanford. LANL is the only remaining U.S. pit production 

facility since the shutdown of Rocky Flats and the Plutonium Finishing Plant Hanford. Site 

profiles completed to date by the SC&A team include Bethlehem Steel, Mallinckrodt Chemical 

Works (MCW), Iowa Army Ammunition Plant (IAAP), Hanford, the Savannah River Site (SRS), 

the Y-12 National Security Complex (Y-12 Plant), Idaho National Engineering and 

Environmental Laboratory (INEEL), the Nevada Test Site (NTS), and the Rocky Flats Plant 

(RFP). Additional site profiles in the process of review are Oak Ridge National Laboratory 

(ORNL), the Mound Plant (Mound), and Fernald (FMPC). LANL had multiple missions that 

overlapped with a number of other sites in the DOE complex, such as weapons research, the heat 

source program, reactor research, assembly and disassembly operations, and tritium operations, 

to name a few. 

To ascertain the differences in assumptions between what assumptions are used for the LANL 

site profile versus other site profiles, the assumptions from each LANL TBD must first be 

understood. The core assumptions for each TBD have been outlined below. 

Dose Reconstruction Assumptions for Occupational Medical Dose 

There was a limited amount of site-specific data related to x-ray equipment and techniques in the 

TBD. Information provided in ORAUT-TKBS-0010-3, Table 3-1 (Johnson 2004, pg. 5) 

indicates that x-ray frequency through the operating period ranged from semi-annually to every 

five years. Claimant-specific information is provided to NIOSH by LANL, and is used to 

supplement the frequencies listed in ORAUT-TKBS-0010-3, Table 3-1 (Johnson 2004, pg. 5). 

The basis for the LANL occupational medical exposure site profile (Johnson 2004) is ORAUTOTIB-0006, Technical Information Bulletin: Dose Reconstruction from Occupationally Related 

Diagnostic X-ray Procedures, Revision 2 (Kathren 2003). In the absence of site-specific data, 

the LANL site profile relied on values provided in this document for occupational medical 

exposure. 

The default values for Occupational Medical Dose are the same as those used in other site 

profiles, as noted on the following pages of the Occupational Medical Dose TBD (Johnson 

2004). 

• 	 Exam included posterior-anterior (PA) and lateral (LAT) views. 

• 	 Dose conversion factors assume minimum collimation for calculating the organ dose for 

Type I x-ray equipment (pg. 6). 
 

 

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• 	 Organ doses from lateral chest x-rays estimated by multiplying the PA Entrance Skin 

Exposure (ESE) by a factor of 2.5 (pg. 6). 

• 	 Dose Conversion Factors (DCFs) outlined in ICRP Publication 34 (ICRP 1982) to assign 

organ dose (pg. 6). 

• 	 Source-to-image distance assumed was 72 inches (pg. 7). 

• 	 No air gaps between the patient and the film (pg. 8) 

• 	 Single phase x-ray units except the three phase Type V unit (pg. 8) 

• 	 Chest thickness for PA chest x-rays is 24 cm and lateral chest x-rays is 36 cm (pg. 7) 

• 	 Added filtration of 2.5 mm for Type I x-rays (pg. 13) 

• 	 Skin dose calculated using a backscatter factor of 1.35 or 1.4 based on NCRP 102 (NCRP 

1989) (pg. 21) 

• 	 Dose conversion factor for the thyroid from Anterior-Posterior (AP) c-spine x-rays 

corrected for depth by 0.2 (pg. 15) 

• 	 Analogue organs used for the organs listed in IREP but not in International Commission 

on Radiation Protection (ICRP) Publication 34 (ICRP 1982, pg. 11) 

• 	 Type II examinations from 1964 to 1976 required interpolation of all listed DCFs, to 

estimate the DCF for the HVL of 7.2 mm Al that was found in available data. ICRP 34 

(ICRP 1982) contains DCFs for (half value layers (HVLs) up to 4.0 mm Al. (pg. 9) 

• 	 Type II examinations from 1977 to 1984, Type IV and Type V equipment assumed an 

HVL of 3.5. For Type III equipment an HVL of 3.0 was used. 

• 	 PFG assumptions based on the methodology in ORAUT-OTIB-0006, Revision 2 

(Kathren 2003). 

• 	 Uncertainty for x-ray procedures is 30% (pg. 17). 

For guidance on lumbar spine exams, the LANL site profile (Johnson 2004) based its 

assumptions on Radiation Doses in Diagnostic X-ray Procedures (Lincoln and Gupton 1958) 

Lumbar spine x-ray dose has been integrated into the latest revision of ORAUT-OTIB-0006, 

Revision 3, PC-1 (Kathren and Shockley 2005). This information should be integrated into 

subsequent revisions of the LANL TBD. 

Dose Reconstruction Assumptions for Occupational Environmental Dose 

ORAUT-TKBS-0010-4 (Cehn and McDowell-Boyer 2004) describes the default assumptions for 

occupational environmental dose at LANL. Supplemental information based on recent data 

review efforts by the NIOSH/ORAU team are provided in Attachment 5 of this report. 

Occupational environmental dose included internal exposures from onsite atmospheric 

radionuclide concentrations, and external exposure from submersion and ambient radiation. 

Values derived for occupational environmental dose were based on environmental measurements 

(i.e., air monitoring data) and emission rates. Other assumptions made with respect to 
 

 

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environmental dose from the Occupational Internal Dose TBD (Cehn and McDowell-Boyer 

2004) include: 

• 	 Environmental measurement data reflect air concentrations from nearby as well as more 

distant sources of emission (pg. 8). 

• 	 Emission estimates are used in the absence of measurement data (pg. 8). 

• 	 Radionuclides of concern were defined as those that resulted in 1 mrem 50-year effective 

dose or 10 mrem to the highest exposed organs (pg. 11). 

• 	 For radionuclide screening, a 1.7 m3/hour inhalation rate over a 2000-hour work year was 

assumed (pg. 11). 

• 	 The radionuclides of concern for environmental dose were tritium, I-131, Th-232, U-234, 

U-238, Pu-238, Pu-239, mixed fission products (MFPs) and particulate and vapor 

activation products (P/VAP) (pg. 11). 

• 	 Where monitoring data were available, the average air concentrations over all stations in 

the TAs were used (pg. 12). 

• 	 For years and locations where data were not available, an estimate based on the source 

emission rate and the air concentration data for available years was made (pg. 12). 

• 	 Ratios between plutonium air concentration and releases in TA-3 and TA-21 were 

derived, and these ratios were applied to effluents from other TAs to obtain an air 

concentration (pg. 12). 

• 	 Pu-239 and Pu-239 specific data were summed and reported in the TBD as Pu-239 

(pg. 13). 

• 	 The specific activity for uranium is based on 0.02% U-234, 2.96% U-235, and 97.02% 

U-238. All uranium was assumed to be U-234 (pg. 13). 

• 	 All mixed fission products were assumed to be Sr-90 (pg. 13). 

• 	 All P/VAP were assumed to be Ge-68, Class W (pg. 13). 

• 	 For post-1970 intakes, the average air concentrations were used to estimate an annual 

intake based on a breathing rate of 2,400 m3

/yr and 2,000 work hours per year (pg. 14). 

• 	 Where the location of the worker could not be determined, the site-wide maximum 

estimated intake was assumed (pg. 14). 

• 	 All particles are considered respirable (pg. 14). 

• 	 The most claimant-favorable solubility is assumed (pg. 14). 

• 	 Site-wide maximum and GM values were calculated based on results from TA-3, TA-18, 

TA-53, and TA-54. Dose is based on 2080-hours per year (pg. 15). 

• 	 A resuspension factor of 1E-9/meter is applied for soil resuspension calculations (pg. 15). 

• 	 When the worker location is unknown, the site-wide maximum ambient radiation dose is 

assigned (pg. 18). 
 

 

 

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• 	 The off-site dose for Los Alamos town site (TA-0) was applied to LANL workers in 

TA-0, TA-2, TA-21, TA-35, TA-41, TA-43, TA-48, TA-53, TA-60, and TA-61 during 

the period of testing. The distance to the receptor is 2.9 kilometers (pg. 18). 

• 	 Average airborne concentrations for Ar-41 in TA-2 were calculated for 1967 forward. 

The source and receptor were assumed to be at the same level (pg. 19). 

• 	 From the noble gas concentrations, the resulting average annual dose was calculated 

based on exposure for 2,000 hours/year (pg. 19). 

• 	 O-15 was used to estimate skin dose from emissions by TA-53, and Ar-42 was used to 

estimate the whole-body dose. The average airborne concentration was determined, and 

an average dose calculated based on 2,000 hours/year. A ground level release was 

assumed (pg. 20). 

Dose Reconstruction Assumptions for Occupational Internal Dose 

ORAUT-TKBS-0010-5 (Argall 2004) describes the default assumptions for occupational internal 

dose at LANL. The assumptions were derived from historical records relating to the in-vivo, the 

in-vitro, and the air monitoring programs. 

Assumptions related to in-vitro analysis in the Occupational Internal Dose TBD (Argall 2004) 

include: 

• 	 Assume the plutonium compound to be plutonium oxide unless otherwise indicated 

(pg. 13). 

• 	 Urine data marked as invalid in the database can be used at the discretion of the dose 

reconstructor (pg. 69). 

• 	 Use the date of intake provided by LANL if it is available. If no intake date is indicated, 

use current models and best judgment in determining the intake date for acute intakes 

(pg. 83). 

• 	 The isotopic mixture for thorium under a best-fit scenario should be based on 

professional judgment. In the case of a maximizing approach, assume Th-230. The 

absorption class (M or S) should be selected based on the expected compound or matrix 

(pg. 33). 

• 	 Assume weapons-grade plutonium (6%), or prior to 1957 (3%). For maximizing intakes, 

assume fuel-grade plutonium (12%) at 10-years old. For intakes since 1996, assume fuelgrade plutonium (12%) at 20-years old (pg. 20). 

• 	 If the results from the thermal ionization mass spectrometry (TIMs) analysis are used for 

dose assessment, Pu-240 must be accounted for in the calculations (pg. 18). 

• 	 Pulmonary absorption types are assumed based on the work location or material 

composition where they are known (pg. 20). 
 

 

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• 	 Tritiated water (HTO) is assumed where specific information is not available on chemical 

form or work location. In the case of HRL and IBF Buildings, the predominant form of 

tritium is organically bound tritium (OBT) (pg. 23). 

• 	 Specific guidance for assessment of OBT and special metal tritides (SMT) doses is 

provided in OCAS-TIB-002 (OCAS 2003, pp. 23–24). 

• 	 The isotopic composition for uranium is defaulted to the values in the Integrated Modules 

for Bioassay Analysis IMBA NIOSH Phase I database USDOE Version 1.0.42, 

Table 5-11 (depleted uranium), or Table 5-12 (enriched uranium) (pp. 25–26). 

• 	 The default absorption for uranium is Type M (pg. 26). 

• 	 Background uranium is subtracted from uranium bioassay results (pg. 29). 

• 	 Any gross beta activity should be considered an occupational intake (pg. 30). 

• 	 Strontium dose is only calculated when bioassay results are available (pg. 31). 

• 	 Missed dose for polonium is assessed only if there is polonium bioassay data, or there is 

an indication of exposure from the claimant interview. Dose should only be assessed for 

those years when polonium bioassay was available (pg. 31). 

• 	 Individual specific polonium baseline values in urine and feces are subtracted from later 

results (pg. 32). 

Other assumptions discussed in the LANL Occupational Internal Dose TBD (Argall 2004) 

related to in-vivo counting include: 

• 	 Detection of Cs-137 in a whole-body count should be considered occupational exposure 

if other fission or activation products are detected, or if fission products, activation 

products, or radiostrontium are detected in the urine (pg. 37). 

• 	 All fission and activation products, excluding Cs-137, identified in a whole-body or lung 

count should be considered unless there is a reason for invalidating dose documented in 

the record (pg. 37). 

• 	 If the record indicates that Cs-137 is from a non-occupational source, the dose should be 

disregarded (pg. 37). 

• 	 If Cs-137 is detected in the whole-body count, and the values are below the mean body 

burdens from fallout derived by the NCRP (NCRP 1987), Cs-137 is assumed to be from 

fallout (pg. 37). 

• 	 In-vivo results and detection limits should be used only to bound intakes determined from 

in-vitro counting for americium, plutonium, and uranium. These results are not used as 

the primary source of determination of intake or missed dose (pg. 38). 

• 	 The standard deviation assumed for whole-body counts is 0.3 times the minimum 

detectable activity (MDA) or reporting level, and for chest counts is 0.5 times the MDA. 

For results greater than 3 times the MDA, assume a standard deviation of 0.1 times the 

result (pg. 41). 
 

 

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• 	 Am-241 observed in lung counts years after the intake are considered in-growth from 

Pu-241 or from the Am-241 in the initial plutonium mixture (pg. 20). 

• 	 Plutonium mixtures should not be inferred from americium results, and the absence of 

americium should not preclude the calculation of dose from americium contribution to 

the mixture. If Am-241 is a part of a mixture, the absorption type is assumed to be the 

same as the plutonium for that mixture (pg. 22). 

• 	 The calculation of missed americium dose is based on sensitivities listed in Table 5-8 of 

the TBD (pg. 23). 

Air Monitoring Data 

• 	 Average airborne concentrations by location and year were calculated from general air 

samples or averages obtained directly from LANL reports (pg. 42). 

• 	 Maximum and average airborne concentrations can be used to establish boundary 

conditions for chronic intakes below the instrument detection levels (pg. 42). 

• 	 Potential missed dose from radionuclides other than plutonium and americium are 

determined based on contamination levels, tolerance and maximum allowable 

concentration (MAC) air concentration levels, and airborne concentration of significant 

radionuclides (pg. 51). 

• 	 For individuals with no early bioassay data for plutonium, uranium, and polonium, but 

bioassay data from later years, the later bioassay data can be used to back-calculate an 

internal dose (pg. 51). 

Average or maximum air concentration data is used to assess intakes for polonium, uranium, and 

plutonium missed dose in 1943–1946. A geometric standard deviation (GSD) of 5 is assumed 

for a hypothetical intake (pg. 51). 

Dose Reconstruction Assumptions for Occupational External Dose 

The LANL Occupational External Dose TBD ORAUT-TKBS-0010-6 (Widner 2005) describes 

the default assumptions for occupational external dose at LANL. The dose assignments were 

based on pocket dosimeter, film badge, neutron track plate, track-etch dosimetry, and 

thermoluminescent dosimeter results. The current Occupational External Dose TBD (Widner 

2005) states that it does not address reconstruction of skin dose. 

Assumptions related to beta/gamma exposure include (Widner 2005): 

• 	 Beta and photon energy distributions are determined by area (pp. 69–70). 

• 	 The default beta and photon energies for input into IREP are > 15 keV beta and 20– 

250 keV photon (pp. 69–70). 

• 	 100% AP geometry is assumed for all workers (pg. 49). 
 

 

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• 	 For operations from 1949, nonpenetrating dose was attributed to beta dose. 

Nonpenetrating dose equals the skin dose minus the sum of the deep dose, neutron dose, 

and tritium dose (pg. 70). 

• 	 For operations prior to 1949, the beta dose is calculated by multiplying the recorded deep 

dose by 1.008. This ratio was derived from median annual shallow-to-deep dose ratios 

for 1949 through 1958. Only values where the deep dose was greater than 50 mrem were 

considered in the analysis. This method applies to reactor operations, uranium 

production, accelerator operations, waste handling, radioactive lanthanum sources, and 

calibration facilities (pg. 70). 

• 	 Low-energy photon exposures are considered pertinent to TA-1 (D-Building), TA-21, 

TA-55 and TA-3 (pg. 69). 

• 	 For plutonium processing and production facilities, low-energy photon exposures are 

evaluated. Before 1949, 100% of the photon dose is attributed to the 30–250 keV energy 

range, and an additional dose of 1.86 times the photon dose is attributed to the <30 keV 

energy range. The low-energy photon dose is in addition to the recorded photon dose. 

For 1949 and after, the nonpenetrating dose should be attributed to the <30 keV energy 

range to account for low energy photons (pg. 69). 

• 	 Missed dose is based on the minimum detectable level/2 times the exchange frequency 

(pg. 68). 

• 	 Missed beta/photon dose is entered as a lognormal distribution with a GSD of 1.52 

(pg. 68). 

• 	 Uncertainty factors for reported LANL doses are provided based on characterization of 

dosimeters by site personnel and the DOELAP analysis. Uncertainties for beta/photon 

dose range from 14%–30%, and for neutron dose range from 8%–50%. The actual value 

is based on the dosimeter type (pg. 67). 

• 	 Adjustment factors for photon doses are recommended for plutonium areas from 1949– 

1962 and 1973–1979. Adjustment factors for photon exposures >200 keV are 

recommended for the brass-cadmium badges from September 1961–October 1964 

(pg. 67). 

• 	 Mean, median, and 95% gamma doses were calculated by year for all dosimeter results 

that were equal to or exceeded 50 mrem. The median dose is assigned to unmonitored 

workers for each year of employment (pp. 65–66). 

Assumptions related to neutron exposure include (Widner 2005): 

• 	 The main work areas where there was a potential for neutron exposures include DBuilding (TA-1), DP West (TA-21), DP East (TA-21), TA-55, Omega Site (TA-2), TA53, Criticality Laboratory (TA-2, TA-18), and the CMR Building (TA-3). Assume the 

plutonium compound to be plutonium oxide unless otherwise indicated (pg. 36). 

• 	 ICRP 60 (ICRP 1991) neutron correction factors were determined for plutonium 

production facilities (TA-1, TA-21 and TA-55), the LAMPF (TA-53), reactor operations 
 

 

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(TA-2, TA-35, TA-52), criticality experiments (TA-2, TA-18), and actinide chemistry 

and metallurgy research (pg. 92). 

• 	 Assume 100% fission spectrum neutrons (0.1 to 1 MeV) for LANL reactors (pg. 43). 

• 	 The neutron spectrum at the Chemical and Metallurgy Research (CMR) facility is 

assumed to be similar to that of the plutonium facilities, but with a slightly higher fraction 

of 2 to 20 MeV neutrons (pg. 43). 

• 	 Missed neutron doses prior to 1979 are based on the application of a neutron-to-photon 

ratio for each work area to the photon dose (pg. 49). 

• 	 The recommended neutron-to-photon ratios are determined for plutonium facilities, 

criticality experiments, and other operations. The neutron-to-photon ratios were 

determined from dosimeter values in 1979–2004 with deep and neutron doses greater 

than or equal to 50 mrem (pg. 35). 

• 	 Work location records are used to determine whether an individual worked in an area 

with neutrons and what the appropriate energy distribution of neutrons was. If no 

neutron dose was assigned to the worker or co-workers for several months, the 

assumption is that the person was not exposed to neutrons and is, therefore, not assigned 

a missed neutron dose (pg. 71). 

Inconsistencies within the LANL Site Profile 

There is some confusion on when to calculate dose based on photofluorography (PFG) 

parameters. The Occupational Medical Dose TBD (Johnson 2004) indicates that PFG should be 

assumed prior to 1957, when no specification of x-ray type is available (pg. 6). Furthermore, it 

indicates that all exams after 1956 are assumed to be chest radiographs (pg. 6). Later the TBD 

(Johnson 2004) states that PFG should be used prior to 1964 when no information on the type of 

exam is available (pg. 10). OTIB-0006 Revision 3 (Kathren and Shockley 2005) also lists 1964 

as the year of the last documented PFG. The direction on when to apply PFG should be clarified 

as it appears to be inconsistent with the document. 

The Occupational External Dose TBD (Widner 2005) states that it does not address skin 

exposure, yet it provides detailed guidance on how to determine non-penetrating and low-energy 

photon doses. These data seem to be providing a methodology to assess skin exposure in spite of 

the statement made in the Occupational External Dose TBD (Widner 2005). This inconsistency 

should be corrected. 

Am-241, H-3, I-131, Pu-239, Th-232, U-234, MFPs (i.e., Sr-90), and P/VAPs (i.e., Ge-68) were 

considered for the site-wide maximum exposures, which are applied when work location is 

unknown. Ambient external dose as well as dose external dose from Ar-41 was considered. 

External dose from Ar-41 was specific to TA-2. Be-7, P-32, As-72, Br-76, Rb-88, Cs-137, 

Cs-138, La-140, Ir-191, Hg-203, and Th-234 were considered; however, the dose contributions 

were <10E-5 Sv/year so this dose was neglected. Other radionuclides, such as Po-210, I-125 

Xe-133, Kr-85, Ra-226, Np-237, C-11, N-13, I-133, I-135, and U-233, were not considered even 

in the screening assessment, yet they were mentioned in the LANL Site Description 

(Buddenbaum 2004). 
 

 

 

 

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Inconsistencies Between Site Profiles 

There is variation among site profiles related to the standard chest thickness and whether an 

adjustment factor is applied. As mentioned above, the thicknesses assumed for LANL were 24 

cm and 36 cm for PA chest x-rays and lateral chest x-rays, respectively. The SRS TBD (Scalsky 

2005) and INEEL TBD assumes a chest thickness of 26 cm and 34 cm for PA chest x-rays and 

lateral chest x-rays, respectively. OTIB-0006 Revision 2 and Revision 3 both indicate that the 

average worker chest size is 22–24 cm (Kathren and Shockley 2005). The OTIB recommends 

that adjustments be applied for larger individuals with chest thicknesses of 25–27 cm and 

> 27 cm chest thickness, resulting in an increase in dose by a factor of 1.5 and 2.0, respectively. 

In the absence of site-specific data, consistent default assumptions are warranted. The LANL 

site profile should reference the most current version of ORAUT-OTIB-0006 when using this 

document in dose reconstruction. 

The NIOSH/ORAU team has recognized that there should be a consideration of exposure by 

receptor points. The application of multiple receptor points is consistent with the approach in the 

Hanford, SRS, and Idaho National Engineering and Environmental Laboratory (INEEL) TBDs. 

The LANL TBD (Cehn and McDowell-Boyer 2004) relies on environmental air sampling data as 

well as applying the χ/Q methodology to determine the annual average air concentrations. The 

Hanford TBD applied the puff advection model (Savignac 2003), while the SRS applied the 

Gaussian model (Scalsky 2005). The assumptions made with respect to ventilation rate and 

exposure time are consistent with other site profiles. Models used within the different 

environmental TBDs are not consistent; nor is an explanation provided for why one applies 

certain models at one DOE site, but not at another. 

Dose from the resuspension of contaminated soil has been given minimal attention in the current 

version of the Environmental Dose TBD (Cehn and McDowell-Boyer 2004), but is currently 

under investigation by the NIOSH/ORAU team. Soil resuspension dose is considered in relation 

to environmental exposure at both the Rocky Flats Plant (McDowell-Boyer and Little 2004) and 

the Savannah River Site (Scalsky 2005). The inclusion of dose from resuspension of soil is 

appropriate for LANL given the numerous weapons test shots the laboratory conducted, 

especially in the early years of operations (Buddenbaum 2004, pp. 12–16). 

The Iowa Army Ammunition Plant TBD (Leonowich et al. 2005) specifically deals with 

hydroshots from both an environmental and internal dose perspective. Although the 

environmental TBD recognizes the potential exposures from the radioactive lanthanum test shots 

conducted at Bayo Canyon, it does not appear to address potential exposures from other testing 

sites including TA-4, TA-5, TA-7 (Gomez Ranch Site), TA-8 (Anchor Site West), TA-12, TA-13 

(P Site), TA-14 (Q Site), TA-20 (Sandia Canyon Site), TA-27 (Gamma Site), TA-40 ( Detonator 

Firing Site), TA-67 (Pajarito Site), and TA-68 (Water Canyon Site). Consideration should be 

given to all test sites as the radionuclides of concern vary. At IAAP, clean-up operations 

presented exposure hazards to fine as well as visible pieces of radioactive material. Since LANL 

has similar operations, this is likely the case at the laboratory. 
 

 

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There is mention of Ra-226 and radon in Table 5A-10 (pg. 70) of the LANL internal dose TBD, 

although there was no discussion included for potential internal dose from radon. Radon was 

specifically addressed in the Mallinckrodt Chemical Workers (MCW) and Fernald TBDs, where 

K-65 residues with high concentrations of Ra-226 were handled; yet the LANL TBD (Argall 

2004) fails to consider radon exposure from the cooking off of sources or leaking of radium 

sources in TA-1. The impact of radon on dose reconstruction should be evaluated, particularly 

for the earlier years. 

During the Y-12 Special Exposure Cohort petition review, considerable attention was given to 

radionuclides generated by the ORNL Isotopes Production Group and potential exposures to 

Y-12 workers from these activities. Similar operations were conducted at LANL at the 

accelerators. The TBD (Argall 2004) does not include a discussion on accelerator-produced 

radionuclides, radionuclides produced during early experiments, and medical radionuclide 

production. Depending on the quantities and types of radioactive material produced, this may 

affect internal dose. 

The LANL Occupational Internal Dose TBD (Argall 2004) simply refers the dose reconstructor 

to the specific guidance provided in OCAS-TIB-002 (OCAS 2003), when the dose records 

indicate an exposure to organically bound tritium (OBT) and metal tritides (MTs). The Mound 

Internal Dosimetry TBD (Millard 2004), in Section 5.3.1.1 Metal Tritides, states that a lung 

clearance class of S should be assumed for all metal tritides other than lithium. The SRS Internal 

Dosimetry TBD and associated TIBs fail to treat the topic of dose reconstruction from exposure 

to organically bound tritium and metal tritides. Consideration should be given to identifying 

those facilities with special tritium compounds and developing a common methodology to assign 

dose from the compounds. 

There has been no consideration of ingestion dose for LANL workers. The Bethlehem Steel and 

the Mallinckrodt Chemical Works (MCW) TBDs included ingestion as a potential route of 

internal dose. This may particularly be appropriate at LANL in the early years when, as the TBD 

indicates, conditions were deplorable. Although engineering controls were implemented over 

time, internal contamination from incidents, reused personal protective equipment, and 

deposition on food and beverages in areas where eating was allowed may have led to ingestion. 

The Hanford, SRS, and other site profiles discount the use of NTA film as an adequate measure 

of neutron dose yet the LANL site profile appears to use NTA film results for monitored 

workers. The LANL Occupational External Dose TBD (Widner 2005) applies an area-specific 

neutron energy distribution for years after 1978. For years prior to 1980, the annual photon dose 

is multiplied by a neutron-to-photon ratio to obtain the neutron dose. The TBD (Widner 2005) 

has derived three neutron-to-photon ratios for the plutonium facilities, criticality experiments 

(> 50 m distant), and other operations. The SRS Occupational External Dosimetry TBD 

distinguishes neutron energies and neutron-to-photon ratios for reactors, fuel fabrication, 

plutonium production, and radionuclide production and calibration (Scalsky 2005). The INEEL 

Occupational External Dose TBD (Rohrig 2004) considers the reactors, the processing plant, 

waste handling operations, calibration sources, and uranium handling. Neutron energy spectra 

and neutron-to-photon ratios for Pu-238 and Pu-239 operations are segregated at SRS (Scalsky 

2005). The categories used in the LANL TBD (Widner 2005) lack the detailed analyses seen in 
 

 

 

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site profiles from other sites. Further evaluation of neutron-to-photon ratios should include more 

specific categories including neutron sources (RaBe, Cf, etc.), accelerators, early subcriticality 

experiments, initiator development and neutron spectra from alternate fissile materials. 

NIOSH/ORAU has proposed to include a Pu-238 specific neutron-to-photon ratio in the next 

revision. 

The Occupational External Dose TBDs for Y-12 (Murray 2003), SRS (Scalsky 2005), and 

Hanford (Scalsky 2003) base their default exposure geometry on the compensability or noncompensability of the claim. The MCW (Westbrook 2005) and RFP (Furman and Lopez 2004) 

Occupational External Dose TBDs base default exposure geometries on job titles. Both the 

LANL TBD (Johnson 2004) and the INEEL (Rohrig 2004) Occupational External Dose TBDs 

default to 100% Anterior-Posterior (AP) exposure. Further evaluation of exposure geometry for 

photon and neutron exposure should be evaluated for LANL workers to determine if 100% AP 

geometry is appropriate for all LANL workers, or whether methods employed at other facilities 

are more appropriate. 

In general, the Integrated RadioEpidemiology Program (IREP) input criteria for Radiation Rate, 

Radiation Type, and Dose Distribution Type are the same for LANL as for other site profiles. 

Maximizing internal dose is assigned with the use of ORAUT-OTIB-0018, Internal Dose 

Overestimates for Facilities with Air Sampling Programs, or ORAUT-OTIB-0002, Technical 

Information Bulletin: Maximum Internal Dose Estimates for Certain DOE Complex Claims. The 

application of these OTIBs for the assignment of dose is consistent with other site profiles. 

External dose assumptions were consistent with those used in other site profiles. The default 

energies for beta, photon, and neutron exposure were >15 keV, 30–250 keV, and 0.1–2.0 MeV, 

respectively. The missed external dose is calculated using the MDL/2 calculation times the 

number of monitoring periods, and is entered as a lognormal distribution with a GSD of 1.52. 

This is consistent with other site profiles. 
 

 

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ATTACHMENT 8: SITE EXPERT COMMENTS ON THE LANL SITE 

PROFILE 

Several comments were provided by individuals interviewed, which related directly to the LANL 

Site Profile documents. These comments are provided as a separate attachment from the site 

expert interview summaries. The information provided below was from interviews and hardcopy 

documentation from Dr. Ken Silver of Eastern Tennessee State University and current 

employees at Los Alamos National Laboratory. 

Comments from Dr. Ken Silver 

Dr. Silver submitted Review and Critique of the Draft NIOSH Site Profile Document for Los 

Alamos National Laboratory to the NIOSH Office of Compensation, Analysis and Support, 

Extensive on September 19, 2005. This document provides a detailed critique of the LANL site 

profile; however, to date NIOSH has not formally responded to Dr. Silver’s comments on the site 

profile. As a result of the issues identified in Dr. Silver’s document, SC&A held a conference 

call with Dr. Silver on November 1, 2005 to get some clarification on the issues raised in his 

review, and on additional concerns he had with the content of the LANL site profile. 

Dr. Silver discussed the following issues as his primary areas of concern regarding the NIOSH 

Los Alamos National Laboratory site profile. 

• 	 NIOSH had access to a number of LANL documents, and simply repackaged the 

documents in their site profile. These technical report documents have not undergone 

external peer review. They documented the “official story” and did not include input 

from workers who experienced the program firsthand. 

• 	 NIOSH/ORAU is having difficulty retrieving necessary data from LANL according to 

chapter five of the Occupational Internal Dose TBD (Argall 2004). As of June 2005, 

ORAU personnel indicated that bioassay data would be forthcoming from LANL within a 

few weeks. The current status of this is unknown. The data being provided may not be 

the raw data, but may include LANL adjustments. 

• 	 Workers have had difficulty establishing their employment at LANL. Early in the 

EEOICPA process, even some of the Construction unions were of little assistance to the 

workers in proving employment. 

• 	 There is a need to have more insight into the data available to NIOSH prior to making 

any decisions on dose reconstruction. 

• 	 The average worker doesn’t have confidence that the dosimeters were properly 

measuring dose. 

• 	 There was reportedly “purging” of dosimetry records for Zia workers. Purportedly, this 

was related to lawyers’ concerns at the time the Zia contract changed. 
 

 

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• 	 There is an inconsistency in the collective doses reported by LANL and those reported to 

DOE in annual dose reports. The numbers used in the LANL site profile were based on a 

2004 internal LANL document that bears no “technical report number. Many times these 

collective doses were lower than those reported to DOE (Silver 2005, pg. 42) 

• 	 NIOSH stated that periodic progress reports were issued until 1960. Some are publicly 

available through 1964. Workers indicated that reports were issued beyond 1964. There 

may be security reasons why reports are not being provided by LANL. Or there may be 

an effort to conceal information about environmental and workplace exposures to fission 

products. For example, they may be withholding reports on the Rover tests, 

Experimental Breeder Reactors, and fuel elements brought back for post mortem studies. 

• 	 A comprehensive list of incidents is absent from the site profile. Based on the many 

issues with the bioassay program cited in the Tiger Team report, one cannot assume the 

bioassay results will capture uptakes from incidents. For example, there were issues with 

who was monitored, how samples were collected, and how samples were handled. 

• 	 TA-21 Decontamination and Decommissioning (D&D) personnel were not required to 

wear respirators. The Occupational Environmental Dose TBD (Cehn and McDowellBoyer 2004) cites a LANL technical report which claims all workers wore respirators. 

• 	 There was a gap noted in the Occupational Environmental Dose TBD (Cehn and 

McDowell-Boyer 2004) for exposure from ambient airborne releases prior to 1970. Dr. 

Silver does not have environmental air monitoring data from this era; however, there are 

technical reports available for years after about 1959. Another issue related to 

environmental exposure is the problem with workers tracking contamination home. This 

was of particular concern on a 1960–1961 underground hydronuclear test. 

• 	 There has been an SEC petition filed by State Representative Harriet Ruiz. The petition 

issues center around the unavailability of medical records for LANL employees and the 

potential impact these records have on dose reconstruction. 

• 	 Dr. Silver has suggested to the Construction Trades that they file a Freedom of 

Information Act (FOIA) request for a “Vaughn index” of NIOSH holdings on LANL for 

the records not yet publicly available. The Waste Disposal Facility (Area G, TA-54) may 

be the subject for a future petition based on the 92 different radionuclides handled in that 

area and issues with instruments. 

• 	 Previous worker interviews indicate that LANL was aware of the disparity between the 

radiation protection procedures and what actually occurred in the field. Documentation 

to this effect has not been located yet. 

• 	 Communication with claimants indicates that the existing LANL site profile is used as a 

basis for denial. 
 

 

 

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Dr. Silver recommended that SC&A consider the following questions during the course of the 

review. 

• 	 How did NIOSH address geometry questions such as Electromechanical Technicians 

sitting on magnets and other equipment at accelerators? 

• 	 What bioassay programs were implemented for workers? 

• 	 Has there been a comparison between the quantities of material processed and the 

availability of bioassay? How did NIOSH address exposure to radionuclides available in 

smaller quantities? 

• 	 How are gaps with pre-1970 environmental data addressed in dose reconstructions? 

• 	 Have sample claims been reviewed to evaluate partial body exposures (e.g., 

Electromechanical Technicians) and individuals handling core samples with potential 

neutron exposure? 

• 	 Why is there a discrepancy in collective dose between the LANL reports and the annual 

reports submitted to DOE? 

• 	 Have egress procedures and spread of contamination to non-radiological areas been 

reviewed, including offsite? 

• 	 Why is it so difficult to establish employment at LANL? 

• 	 What is the quality of the data provided to NIOSH? 

Several follow-up discussions were held with Dr. Silver during the course of the review to 

identify potential sources of information on the above topics. Dr. Silver recommended several 

sources of information pertinent to dose reconstruction and the historical radiation protection 

program. 

• 	 Appendices to the Tiger Team report on microfiche – supplement to the report which 

may provide further information. 

• 	 Institutional History Document in 3 volumes – helpful in determining the structure of the 

Radiation Protection Program through time. 

• 	 Information on Human Radiation Experiments for the 1940s and 1950s also contained 

information on measurement of occupational exposures. Because the human experiments 

ended after the 1950s, information on occupational exposures in the 1960s and 1970s is 

not available in the public domain. Harry Schulte and Harry Jordan wrote journal articles 

on worker and environmental exposures. 

• 	 LA-6848-MS, Author Margaret Rogers 
 

 

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• 	 Zia worker study (Galke et al. 1992) 

• 	 Article on the Medical Health Surveillance program by Brian S. Schwartz (see American 

Journal of Industrial Medicine) 

• 	 University of New Mexico Zimmerman Library – Copies of FOIA requests maintained 

here (along with CDC LAHDRA documents). 

Dr. Silver recommended several site experts to SC&A that he felt would provide valuable 

information on LANL operations and safety. These individuals included personnel from 

RadCon, dosimetry, the accelerators, waste management, D&D, Construction Trades, and 

outside individuals who have conducted research related to LANL. 

Comments on the Occupational Environmental Dose TBD 

There were several improvements recommended by LANL staff related to the NIOSH 

Occupational Environmental Dose TBD (Cehn and McDowell-Boyer 2004) 

• 	 As the early releases were likely more significant, retrieval of early environmental 

monitoring data would be beneficial (1940s, 1950s). Less is known about this period of 

time than other periods. 

• 	 The data from the annual Environmental Surveillance Reports need to be considered in 

context. Often, the data are measured close to a source of radiation or contamination and 

do not represent the exposure to a general worker onsite. 

• 	 The maximum environmental air sampling data has been assumed as the most appropriate 

number for dose reconstruction by NIOSH without consideration of air monitor position 

or restricted access to areas. It is incorrect and misleading to use these data for all site 

personnel. For example, there is a sampler adjacent to tritium disposal shaft. The 

ambient air sampling levels is high because of the location. 

• 	 There is no explanation of where the data in Table 4A-1 (Cehn and McDowell-Boyer 

2004) was obtained. LANL and Center for Disease Control and Prevention (CDC) 

contractor personnel are currently working to locate data from the 1940s for TA-1. 

• 	 There was a contamination problem with environmental air samples from the Second 

Quarter of 1995. The data is qualified in LA-13210-ENV, Environmental Surveillance at 

Los Alamos During 1995 (LANL 1996, pg. 85). The NIOSH Occupational 

Environmental Dose TBD (Cehn and McDowell-Boyer 2004) did not take this into 

account. 

• 	 Table 4B-1 (Cehn and McDowell-Boyer 2004) lists the Estimated Maximum Effective 

Dose for 1967 from Th-232 as 8.3E2 Sv/year. The Estimated Maximum Effective dose 
 

 

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for 1950 from U-234 is 3.3E-1 Sv/year. These doses are excessive and there is no 

justification for them. 

• 	 In Table 4C-12 (Cehn and McDowell-Boyer 2004), the estimated decrease from 1970 to 

1971 is a factor of 200. This suggests the earlier values are overestimated by a factor of 

200. This discontinuity needs to be further investigated. 

• 	 The list of references in the NIOSH Occupational Environmental Dose TBD (Cehn and 

McDowell-Boyer 2004) is short compared to the thousands of relevant references (i.e., 

memos, progress reports) available through LANL. There are reports from 1958–1971. 

The reports for earlier years are more sporadic. 

• 	 The environmental monitoring group at LANL provided documentation to NIOSH, but 

was not provided an opportunity to comment on the NIOSH TBD after it was final. 

HSR-12 and HSR-4 had an opportunity to comment on portions of the Occupational 

Environmental Dose TBD (Cehn and McDowell-Boyer 2004). 

• 	 The Occupational Environmental Dose TBD (Cehn and McDowell-Boyer 2004) does not 

include information from the EPA regarding the Cerro Grande Fire. LANL workers 

requested that this information be included in the site profile for LANL. 

There was a concern expressed by environmental monitoring staff that the use of overestimates 

of environmental doses in the NIOSH dose reconstruction process undermines the best estimate 

values derived using reasonable assumptions by LANL. 

Comments from Other Site Experts 

• 	 Site experts in general felt the Site Description TBD (Buddenbaum 2004) presented a 

good history of the site operations. In particular, the TA-18 description was “pretty 

good.” 

• 	 The NIOSH/ORAU team interviewed several of the Radiological Control staff at LANL, 

including members of the Dose Assessment, External Dosimetry, and current and former 

Medical staff. Questions were related to the dosimetry and medical programs. Although 

the NIOSH/ORAU team held worker outreach meetings, there was not focused effort to 

interview personnel outside the HSR group. 

• 	 LANL staff recognized the incompleteness of the incident file provided in the NIOSH 

Site Description incident list, which seems to be a very small and arbitrary subset of the 

recorded incidents. There were incidents missing which resulted in intakes or 

overexposure. For example, the NIOSH incident list did not include the March 2000 

event involving a group of workers from PF4 who received internal uptakes of Pu-238. 

The negative pressure was not operating. As a result, a radiological control technician 

(RCT) crawled under the glove box. While there, the swage lock fitting blew out. There 

were no incidents listed after 1978, when in fact they did occur. There were also some 
 

 

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apparent gaps in the NIOSH Internal Dosimetry (Argall 2004) incident list. The incidents 

in these lists can easily be cross-checked against hardcopy incident files and/or the 

Incident Database. In fact, the Dose Assessment Team indicated that the total number of 

exposures at the laboratory was much larger than the NIOSH incident lists. 

• 	 Some Dose Assessment team members expressed their concern with the legal and 

political nature of the NIOSH dose reconstruction program versus its scientific basis. 

During the dose reconstruction process for EEOICPA, records of officers traveling to other DOE 

sites were not included as a part of the LANL record and were not requested by LANL-DOE for 

submission to NIOSH. A true dosimetry reading is unlikely for LANL employees traveling offsite to other DOE facilities.