ORAU TEAM

Dose Reconstruction

Project for NIOSH

Oak Ridge Associated Universities I Dade Moeller & Associates I MJW Corporation

Page 1 of 10

Document Title:

Los Alamos National Laboratory – Introduction

Document Number: ORAUT-TKBS-0010-1 

Revision: 01

Effective Date: 10/01/2007

Type of Document TBD

Supersedes: Revision 00

Subject Expert(s): Jack E. Buddenbaum

Site Expert(s): N/A

Approval: Signature on File Approval Date: 09/12/2007

Donald N. Stewart, Document Owner

Concurrence: Signature on File Concurrence Date: 09/12/2007

John M. Byrne, Task 3 Manager

Concurrence: Signature on File Concurrence Date: 09/12/2007

Edward F. Maher, Task 5 Manager

Concurrence: Signature on File Concurrence Date: 09/27/2007

Kate Kimpan, Project Director

Approval: Brant A. Ulsh Signature on File for Approval Date: 10/01/2007

James W. Neton, Associate Director for Science

 New Total Rewrite Revision Page Change

FOR DOCUMENTS MARKED AS A TOTAL REWRITE, REVISION, OR PAGE CHANGE, REPLACE THE PRIOR 

REVISION AND DISCARD / DESTROY ALL COPIES OF THE PRIOR REVISION. 
Document No. ORAUT-TKBS-0010-1 Revision No. 01 Effective Date: 10/01/2007 Page 2 of 10

PUBLICATION RECORD

EFFECTIVE 

DATE

REVISION

NUMBER DESCRIPTION

01/25/2005 00 New technical basis document for Los Alamos National Laboratory -

Introduction. First approved issue. Incorporates formal internal and 

NIOSH review comments. Initiated by Jack E. Buddenbaum.

10/01/2007 01 Approved Revision 01 initiated to include References and Attributions 

and Annotations sections. Minor editorial changes made. No further 

changes occurred as a result of formal internal review. Incorporates 

formal NIOSH review comments. Training required: As determined 

by the Task Manager. Initiated by Donald N. Stewart.
Document No. ORAUT-TKBS-0010-1 Revision No. 01 Effective Date: 10/01/2007 Page 3 of 10

TABLE OF CONTENTS

SECTION TITLE

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

PAGE

4

1.0 Introduction ..............................................................................................................................5

 1.1 Purpose........................................................................................................................6

 1.2 Scope...........................................................................................................................6

 1.3 Attributions and Annotations.........................................................................................9

References ........................................................................................................................................10
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ACRONYMS AND ABBREVIATIONS

Ci curie

DOE U. S. Department of Energy

EEOICPA Energy Employees Occupational Illness Compensation Program Act of 2000

LAMPF Los Alamos Meson Physics Facility

LANL Los Alamos National Laboratory

LASL Los Alamos Scientific Laboratory

NIOSH National Institute for Occupational Safety and Health

ORAU Oak Ridge Associated Universities

OWR Omega West Reactor

POC probability of causation

TBD technical basis document

U.S.C. United States Code 

§ section or sections
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1.0

Technical basis documents and site profile documents are not official determinations made by the 

National Institute for Occupational Safety and Health (NIOSH) but are rather general working 

documents that provide historic background information and guidance to assist in the preparation of 

dose reconstructions for particular sites or categories of sites. They will be revised in the event 

additional relevant information is obtained about the affected site(s). These documents may be used 

to assist NIOSH staff in the completion of the individual work required for each dose reconstruction.

INTRODUCTION

In this document the word “facility” is used as a general term for an area, building, or group of 

buildings that served a specific purpose at a site. It does not necessarily connote an “atomic weapons 

employer facility” or a “Department of Energy [DOE] facility” as defined in the Energy Employees 

Occupational Illness Compensation Program Act [EEOICPA; 42 U.S.C. § 7384l(5) and (12)]. 

EEOICPA defines a DOE facility as “any building, structure, or premise, including the grounds upon 

which such building, structure, or premise is located ... in which operations are, or have been, 

conducted by, or on behalf of, the Department of Energy (except for buildings, structures, premises, 

grounds, or operations ... pertaining to the Naval Nuclear Propulsion Program)” [42 U.S.C. 

§ 7384l(12)]. Accordingly, except for the exclusion for the Naval Nuclear Propulsion Program noted 

above, any facility that performs or performed DOE operations of any nature whatsoever is a DOE 

facility encompassed by EEOICPA.

For employees of DOE or its contractors with cancer, the DOE facility definition only determines 

eligibility for a dose reconstruction, which is a prerequisite to a compensation decision (except for 

members of the Special Exposure Cohort). The compensation decision for cancer claimants is based 

on a section of the statute entitled “Exposure in the Performance of Duty.” That provision [42 U.S.C. 

§ 7384n(b)] says that an individual with cancer “shall be determined to have sustained that cancer in 

the performance of duty for purposes of the compensation program if, and only if, the cancer ... was 

at least as likely as not related to employment at the facility [where the employee worked], as 

determined in accordance with the POC [probability of causation1

As noted above, the statute includes a definition of a DOE facility that excludes “buildings, structures, 

premises, grounds, or operations covered by Executive Order No. 12344, dated February 1, 1982 

(42 U.S.C. 7158 note), pertaining to the Naval Nuclear Propulsion Program” [42 U.S.C. § 7384l(12)]. 

While this definition contains an exclusion with respect to the Naval Nuclear Propulsion Program, the 

section of EEOICPA that deals with the compensation decision for covered employees with cancer 

[i.e., 42 U.S.C. § 7384n(b), entitled “Exposure in the Performance of Duty”] does not contain such an 

exclusion. Therefore, the statute requires NIOSH to include all occupationally derived radiation 

exposures at covered facilities in its dose reconstructions for employees at DOE facilities, including 

radiation exposures related to the Naval Nuclear Propulsion Program. As a result, all internal and 

external dosimetry monitoring results are considered valid for use in dose reconstruction. No efforts 

are made to determine the eligibility of any fraction of total measured exposure for inclusion in dose 

reconstruction. NIOSH, however, does not consider the following exposures to be occupationally 

derived:

] guidelines established under 

subsection (c) ...” [42 U.S.C. § 7384n(b)]. Neither the statute nor the probability of causation

guidelines (nor the dose reconstruction regulation) define “performance of duty” for DOE employees 

with a covered cancer or restrict the “duty” to nuclear weapons work.

• Radiation from naturally occurring radon present in conventional structures

• Radiation from diagnostic X-rays received in the treatment of work-related injuries

 

1 The U.S. Department of Labor is ultimately responsible under the EEOICPA for determining the POC. 
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1.1 PURPOSE

This Site Profile describes the Los Alamos National Laboratory (LANL) site. Dose reconstructors can 

use the information in this Site Profile as a substitute for or supplement to worker exposure 

information to evaluate occupational radiation exposures.

This Site Profile consists of this Introduction and five technical basis documents (TBDs) with 

supporting tables and attachments. This Introduction provides a summary description of the five TBD 

sections: Site Description, Occupational Medical Dose, Occupational Environmental Dose, 

Occupational Internal Dose, and Occupational External Dosimetry. 

1.2 SCOPE

The Site Description TBD (ORAUT 2004a) presents a brief description of the facilities and processes 

that have been used in the development of nuclear weapons since the early 1940s. 

DOE owns LANL in northern New Mexico. From 1943 to 1981, the site was known as the Los Alamos 

Scientific Laboratory (LASL). The University of California has managed the laboratory since its 

establishment in 1943 as part of the Manhattan Project to create the first atomic weapons. LANL’s 

responsibilities have expanded since then to include thermonuclear weapons design, high-explosives 

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

waste incineration, chemistry, criticality experimentation, tritium handling, biophysics, and 

radiobiology.

From time to time, Los Alamos also performed special functions in its backup role to Hanford and the 

Rocky Flats Plant. For example, because of an accident at the Hanford Plutonium Finishing Plant in 

1984, plutonium was sent in oxide form to Los Alamos for conversion to metal. In addition, Los 

Alamos served in a backup role for limited periods after major fires in plutonium facilities at Rocky 

Flats in 1957 and 1969. Today, LANL is the only remaining U.S. pit production facility.

Operations at Los Alamos have taken place in land divisions called technical areas (TAs). The 

current convention for describing locations at LANL is TA 3 66, where 3 is the area number and 66 is

the building number. For TA 3, buildings are identified by letters (for example, TA 3-29 Building 29). 

Some buildings in TA 3 are identified as SM 66 for South Mesa Site. 

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 weapons critical assemblies on a limited scale until 

the late 1950s. Other radionuclides that were handled on a smaller scale in comparison with 

plutonium and uranium included americium, polonium, lanthanum, and barium. Starting in 1946, 

TA-21 (also known as 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, during the next several years, the DP sites underwent decontamination and 

decommissioning. The Chemistry and Metallurgy Research at TA-3 processed primarily plutonium, 

uranium, and americium.

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

reactors, Plutonium Fast Reactor [also known as Clementine (1946 to 1950)], Omega West Reactor 

(1956 to 1992), and other reactors for critical experiments that were later moved to TA-18 in 1947. 

Early reactors, which were 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 that were designed, and in some cases built and operated, at Los Alamos. While some of 
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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, formerly known as the Los Alamos Meson Physics Facility 

(LAMPF), 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, radioactive airborne emissions have accounted for the 

largest boundary doses from all of LANL operations. For example, 117,000 Ci of air activation 

products were released to the environment from LAMPF in 1978 (LASL 1979). Principal radionuclides 

that were released to the air include 41Ar, 11C, 13N, and 15O.

The Occupational Medical Dose TBD (ORAUT 2004b) provides information about the dose that 

individual workers received from X-rays that were required as a condition of employment. These 

X-rays included preemployment and annual chest X-rays during annual physical examinations. The 

frequency of required X-rays varied over time and also as a function of worker age. 

Both the X-ray equipment and the techniques for taking X-rays have changed over the years covered 

by this TBD. These factors have been taken into account in determining the dose that a worker would 

have received from the X-ray. When there was a doubt about the technique used, assumptions 

favorable to claimants have been made to ensure the dose has not been underestimated. The 

parameters that have been investigated include the tube current and voltage, exposure time, filtration, 

source-to-skin distance, the view (posterior-anterior or lateral), and any other factor that could affect 

the dose the worker received.

The doses to other exposed organs from the chest X-ray have also been calculated. The doses take 

into account the uncertainty that is associated with each of the parameters that is mentioned above. 

The doses that were received by the various organs in the body are presented in tables for convenient 

reference by the dose reconstructors.

The Occupational Environmental Dose TBD (ORAUT 2004c) applies to workers who were not 

monitored for external or internal radiation exposure. The environmental dose is the dose workers 

received when working outside the buildings on the site from inhalation of radioactive materials in the 

air, direct radiation from plumes (immersion dose from radioactivity in the air), contact with radioactive 

particles on the skin, and from direct exposure to radionuclides that were incorporated in the soil.

Exposure to these sources can result in an internal dose to the whole body or body organs from

inhalation of the radioactive materials or could result in a whole- or partial-body external dose from 

deposited radionuclides or submersion in the cloud of radioactive material. 

The radionuclide concentrations within the TAs at LANL are based on the source terms that were 

developed from air-monitoring stations and release estimates. Screening analyses in Section 4 of the 

LANL site profile have demonstrated that the radionuclides 3

H, 131I, 41Ar, 238Pu, 239Pu, 232Th, 235U, 238U, 

and 90Sr contributed the greatest dose to site workers. Other radionuclides that were evaluated 

included 241Am 11C, 13N, 15O, 137Cs. The solubility of several of these radionuclides is discussed in 

Sections 2, 4, and 5 of LANL site profile documents (ORAUT 2004a, 2004d, 2004e). 

Intakes of radionuclides by workers were assumed to occur near the air-monitoring stations from 

which sampling data were taken to estimate air concentrations. These data can be found in Section 
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4.2 tables (e.g., Tables 4-1 and 4-2). Source emissions, screening results, and air concentrations are 

presented in Attachments A, B, C, and D to this TBD along with source term data and submersion 

doses. 

The external dose to workers from the ambient radiation levels on site and from submersion in a cloud 

of radioactive material are also presented along with the skin dose from the 41Ar.

The Occupational Internal Dose TBD (ORAUT 2004d) discusses the internal dosimetry program at 

LANL. At first, there was no bioassay program to determine the internal dose workers could have 

received. Starting in 1944, blood tests were performed after potential exposures. However, these 

blood tests were performed for blood count levels in relation to external radiation exposure rather than 

the radioactive content of the blood. Therefore, records of blood counts that were performed on an 

individual or mentioned in claimant interviews are not directly applicable to internal dose calculations. 

Many of the exposure histories and work records are not specific about the assigned work areas of 

individuals. However, when information about the work location is available, assumptions favorable to 

claimants have been made to provide the dose reconstructors with the ability to determine worker 

dose in these early periods. Section 5.2 discusses in vitro methods for specific radionuclides. 

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 significant potential for exposure were monitored. Although the number of 

monitored individuals has increased, not all individuals who work at LANL are currently monitored. A 

survey in 1986 estimated that approximately 350 persons had known burdens of plutonium. 

Air samples, identifiable with the individual records, were performed beginning in 1944. These data 

along with coworker data can be used to estimate doses for unmonitored workers as deemed 

appropriate by the dose reconstructors.

As the state of the art of radiation detection progressed, whole-body counting for fission products was 

begun in 1955, chest counting was begun in 1970, and wound counting was performed beginning 

before 1967. Section 5.3 discusses the historical and current in vivo bioassay methods. 

The bioassay program was developed and constantly improved over the years as technology 

progressed. Electronic databases were developed to maintain urinalysis records. This is discussed 

along with the various codes LANL used to identify the specific analyses. Much of the older 

monitoring data that are needed for LANL claims are not in a format that is easily retrieved. NIOSH 

and Oak Ridge Associated Universities (ORAU) Team members are currently developing a new 

bioassay database for all in vitro and in vivo results that will allow access to a complete set of records 

for all available data for a given claimant. Detailed information is provided in the database to assist 

the dose reconstructors in interpreting data they might encounter in worker records. 

This TBD discusses the in vitro minimum detectable activities, the analytical methods, and the 

reporting protocols for the radionuclides that have been encountered at LANL. These aspects of the 

bioassay program varied over the years for each of the evaluated radionuclides (i.e., plutonium, 

americium, tritium, uranium, polonium, and fission products). Details of the monitoring techniques and 

programs are presented in this TBD.

Discussions are provided that present information on the specific radionuclides to which workers in 

each of the various facilities could have been exposed. Information is provided for the periods when 

processes changed as a result of improvements in the processing systems.
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Interferences that might have been encountered in the collection and analysis of bioassay samples 

are discussed, as are the uncertainties in the bioassay measurements. Information is presented for 

workers with no confirmed intakes but who may have been exposed in the early days when the 

detection capability and sampling techniques were poor or there were missed samples. Methods for

evaluation of potential doses that might fall in this category are presented. Additional data are

provided for the evaluation of the worst-case scenario and for unmonitored workers.

Many tables are provided in this TBD to aid the dose reconstructor in evaluation of the potential doses 

workers received under all circumstances. 

The Occupational External Dose TBD (ORAUT 2007) discusses the program for measurement of skin 

and whole-body doses to the workers. The methods for evaluation of external doses to workers have 

also evolved over the years as new techniques and equipment have been developed. Concepts in 

radiation protection have also changed. The dose reconstruction parameters, LANL practices and 

policies, and dosimeter types and technologies for measuring the dose from the different types of 

radiation are discussed in this section. Attention is given to the evaluation of doses that were 

measured from exposure to beta, gamma, and neutron radiation. Test results are tabulated for 

various dosimeters that were exposed to different exposure geometries and radiation energies.

Sources of bias, workplace radiation field characteristics, responses of the different beta/gamma and 

neutron dosimeters in the workplace fields, and the adjustments to the recorded dose that has been 

measured by these dosimeters during specific years are discussed in detail.

There are sources of potential dose that could be missed because of the limitations of dosimetry 

systems and the methods of reporting low doses. This missed dose is discussed as a function of 

facility location, dosimeter type, year, and energy range. Attachment A to this TBD describes the use 

of the external dosimetry technical basis parameters to facilitate the efforts of the dose reconstructors.

1.3 ATTRIBUTIONS AND ANNOTATIONS

All information requiring identification was addressed via references integrated into the reference 

section of this document.
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REFERENCES

LASL (Los Alamos Scientific Laboratory), 1979, Environmental Surveillance at Los Alamos During 

1978, Environmental Studies Group, Los Alamos, New Mexico, April.

ORAUT (Oak Ridge Associated Universities) 2004a, Technical Basis Document for the Los Alamos 

National Laboratory – Site Description, ORAUT-TKBS-0010-2, Rev. 00, Oak Ridge, 

Tennessee, May 7.

ORAUT (Oak Ridge Associated Universities) 2004b, Technical Basis Document for the Los Alamos 

National Laboratory – Occupational Medical Dose, ORAUT-TKBS-0010-3, Rev. 00, Oak 

Ridge, Tennessee, December 29.

ORAUT (Oak Ridge Associated Universities) 2004c, Technical Basis Document for the Los Alamos 

National Laboratory – Occupational Environmental Dose, ORAUT-TKBS-0010-4, Rev. 00, Oak 

Ridge, Tennessee, October 8.

ORAUT (Oak Ridge Associated Universities) 2004d, Technical Basis Document for the Los Alamos 

National Laboratory – Occupational Internal Dose, ORAUT-TKBS-0010-5, Rev. 00, Oak 

Ridge, Tennessee, December 21.

ORAUT (Oak Ridge Associated Universities) 2007, Los Alamos National Laboratory – Occupational 

External Dose, ORAUT-TKBS-0010-6, Rev. 00, Oak Ridge, Tennessee, May 30.