ORAU TEAM

Dose Reconstruction

Project for NIOSH

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

Page 1 of 10

Document Title:

Hanford Site – Introduction

Document Number: ORAUT-TKBS-0006-1 

Revision: 02

Effective Date: 08/30/2006

Type of Document: TBD

Supersedes: Revision 01

Subject Expert: Edward D. Scalsky

Document Owner

Approval: Signature on File Approval Date: 08/28/2006

Edward D. Scalsky, TBD Team Leader

Approval: Richard Merrill Signature on File for Approval Date: 08/17/2006

John M. Byrne, Task 3 Manager

Concurrence: Signature on File Concurrence Date: 08/18/2006

Edward F. Maher, Task 5 Manager

Concurrence: Signature on File Concurrence Date: 08/17/2006

Kate Kimpan, Project Director

Approval: Signature on File Approval Date: 08/30/2006

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-0006-1 Revision No. 02 Effective Date: 08/30/2006 Page 2 of 10

PUBLICATION RECORD

EFFECTIVE 

DATE

REVISION 

NUMBER DESCRIPTION

11/07/2003 00 First approved issue. Initiated by Edward D. Scalsky.

12/05/2003 01-A Revised to add page headers, correct editorials, acronyms and to 

change references to TBD to Site Profile where applicable. Initiated 

by Edward D. Scalsky.

12/23/2003 01-B Incorporates OCAS comments. Initiated by Edward D. Scalsky.

01/09/2004 01 Approved issue of Revision 01. Initiated by Edward D. Scalsky.

08/30/2006 02 Revised as a result of biennial review. Approved issue of Revision 

02. Constitutes a total rewrite of the document. Incorporates formal 

internal and NIOSH review comments. This revision results in no 

change to the assigned dose and no PER is required. Training 

required: As determined by the Task Manager. Initiated by Edward 

D. Scalsky.
Document No. ORAUT-TKBS-0006-1 Revision No. 02 Effective Date: 08/30/2006 Page 3 of 10

TABLE OF CONTENTS

SECTION TITLE 

Acronyms And Abbreviations...............................................................................................................

PAGE

4

 

1.1 Introduction..................................................................................................................................5

1.2 Purpose .......................................................................................................................................6

1.3 Scope ..........................................................................................................................................6

1.4 Discussion ...................................................................................................................................6

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

DOE U. S. Department of Energy

EEOICPA Energy Employees Occupational Illness Compensation Program Act of 2000

IMBA Integrated Modules for Bioassay Analysis

IREP Interactive RadioEpidemiological Program 

MDA minimum detectable activity 

NIOSH National Institute for Occupational Safety and Health

ORAU Oak Ridge Associated Universities

POC probability of causation

PUREX Plutonium-Uranium Extraction

REDOX Reduction/Oxidation

TBD technical basis document

U.S.C. United States Code

§ section
Document No. ORAUT-TKBS-0006-1 Revision No. 02 Effective Date: 08/30/2006 Page 5 of 10

1.1 INTRODUCTION

Technical basis documents (TBDs) 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 at 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 the NIOSH staff in the completion of the individual work required for each dose 

reconstruction.

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) of 2000 [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 occupationallyderived:

] 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.

 

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

causation (POC). 
Document No. ORAUT-TKBS-0006-1 Revision No. 02 Effective Date: 08/30/2006 Page 6 of 10

• radiation from naturally-occurring radon present in conventional structures;

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

1.2 PURPOSE

The purpose of this Introduction is to provide a summary of the contents of the five TBDs that, along 

with this introduction, constitute the Hanford Site Profile.

1.3 SCOPE

The Site Profile is divided into this Introduction and five major TBDs: Site Description, Occupational 

Medical Dose, Occupational Environmental Dose, Occupational Internal Dose, and Occupational 

External Dosimetry. This Introduction briefly describes the contents of those five TBDs. 

1.4 DISCUSSION

This Hanford Site Profile provides supporting technical data to evaluate, with assumptions favorable 

to claimants, the total Hanford occupational radiation dose that can reasonably be associated with the 

worker’s radiation exposure. This dose results from exposure to external and internal radiation 

sources in Hanford facilities, to Hanford occupationally required diagnostic X-ray examinations, and to 

onsite environmental releases. In addition, the Site Profile examines the dose that could have 

occurred while the worker was not monitored or dose that could have been missed. Over the years

since operations at Hanford began, new and more reliable scientific methods and protection 

measures have been developed. The methods needed to account for these changes are identified in 

this Site Profile. 

This Site Profile can be a tool when performing dose reconstructions for Hanford workers. The 

Integrated Modules for BioAssay Analysis (IMBA) computer code is a tool useful for internal dose 

calculations. Information on measurement uncertainties is an integral component of the NIOSH 

approach. This document describes how to evaluate uncertainty associated with Hanford exposure 

and dosimetry records.”

The Site Description TBD (latest version of ORAUT 2004a) briefly describes the facilities and 

processes used in the development of nuclear weapons and other programs at Hanford since the 

early 1940s.

Over time, there were more than 500 facilities on the 600-square-mile Hanford Site that contributed to 

the mission of producing plutonium, uranium, tritium, and other radionuclides that contributed not only 

to the weapons program but also to the space program and the medical profession. These facilities 

were used for radiation effects studies, nuclear physics research and development, criticality studies, 

calibrations, radiochemistry development, radiometallurgy, biochemistry, process equipment 

development, and many other applications.

Beginning in 1944, nine production reactors were operated to produce plutonium by the irradiation of 

metallic uranium fuel elements. In addition to the plutonium production, Hanford conducted 

experiments on other defense-related radionuclides such as the irradiation of thorium to produce 233U, 

depleted uranium to produce 240Pu, neptunium targets to produce 238Pu, and americium to produce 

medical-grade 238Pu.
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In addition to the production reactors, there were seven testing, research, and demonstration reactors 

used for testing fuel elements and fuel configurations, measuring changes due to various types of fuel 

elements, measuring the thermal impact on fission cross-sections, studying reactor physics 

technology, performing long-term testing of reactor materials, producing medical radioisotopes, and 

researching power systems for use in space. 

The reactor products had to be chemically separated for use in the weapons program. These 

chemical separations were done in the T- and B-Separations Canyons. The complex chemical and 

physical processes performed in these canyons separated uranium, plutonium, and fission products. 

Plutonium was separated from the uranium and fission products by a bismuth-phosphate precipitation 

batch process. Additional processing resulted in the desired final plutonium product. The chemical 

separations processes changed over the years from the bismuth-phosphate precipitation process to 

the reduction oxidation (REDOX) process to the plutonium–uranium extraction (PUREX) process. 

Both the REDOX and PUREX processes used organic solvent extraction processes. Each process 

improved the recovery of uranium, plutonium, and other radionuclides such as neptunium.

In addition to the production and separations facilities, there were three facilities for fuel fabrication: 

the Uranium Metal Fuels Fabrication facility, the Uranium Metal Extrusion facility, and the Fuel 

Cladding facility. There were also two support facilities, the Uranium Storage and Oxide Burner 

facility and the Reactor Fuel Manufacturing Pilot Plant.

Waste handling facilities were present on the site to handle the high- and low-level radioactive wastes 

produced in the various processes mentioned above. The U-Plant was used for the recovery of 

uranium from high-level liquid wastes from the B- and T-Plants. The U-Plant operated from 1952 until 

January 1958. Various other facilities were built to support the separations process for the uranium, 

plutonium, neptunium, and tritium.

The Occupational Medical Dose TBD (ORAUT 2005) provides information about the dose that 

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

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

required X-rays varied over time and as a function of the worker’s age. All workers received annual 

chest X-rays from before 1946 to 1959. From April 12, 1959, to January 28, 1983, workers over 

50 years of age received annual X-rays, while workers from 40 to 49 received X-rays biennially, and 

those under the age of 40 received an X-ray every 3 years. This frequency changed from January 28, 

1983, to March 30, 1990, during which time employees over 50 received an X-ray biennially, those 40 

to 49 every third year, and the under 40 age group every fifth year. From March 30, 1990, to April 22, 

1997, all employees received an X-ray every fifth year. From April 22, 1997, to the present, X-rays 

have been given only as required.

Both the X-ray equipment and the techniques used 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. Where there was doubt about the technique used, 

assumptions favorable to claimants were made to ensure that the worker’s dose would not be 

underestimated. The investigated parameters 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 received by the worker.

The doses to other exposed organs from chest X-rays have also been calculated. The calculated 

doses take into account the uncertainty associated with each of the parameters. Tables in this TBD 

list the doses received by the various organs in the body as a convenient reference for the dose 

reconstructors. . 
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The Occupational Environmental Dose TBD (ORAUT 2003) applies to workers who were not 

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

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

the air, direct radiation from plumes, contact with particles on the skin, and direct exposure to 

radionuclides that could have become incorporated in the soil.

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

inhalation of radioactive materials, and it can result in a whole- or partial-body external dose from 

radionuclides deposited on the skin or submersion in the cloud of radioactive material. 

The radionuclide concentrations in Hanford areas are based on the source terms developed by 

others. Screening studies have demonstrated that 131I, 41Ar, 144Ce144Pr, 137Cs, 239Pu, 103Ru103Rh, 

106Ru106Rh, 90Sr, 90Sr90Y contributed the greatest dose to site workers. This TBD discusses the 

solubilities of several of these radionuclides.

Intakes of radionuclides by workers at specific locations on the site were calculated using the 

Regional Atmospheric Transport Code for Hanford Emission Tracking (RATCHET) computer program 

and a spreadsheet. Attachment A to this TBD lists these intake data along with source term data and 

submersion doses. 

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

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

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

Hanford reservation. From the beginning of Hanford operations in 1943 until 1946, personnel 

monitoring was the responsibility of the Medical Department. At that time, there was no bioassay 

program to determine the internal dose that workers could have received. Therefore, assumptions 

favorable to claimants have been made to provide the dose reconstructors with the ability to 

determine a worker’s dose in this early period. Later, the bioassay program was developed and 

constantly improved over the years as technology progressed. Electronic databases were developed 

to maintain urinalysis records. These are discussed along with the various codes used to identify the 

specific analysis performed.

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

reporting protocols for the radionuclides at Hanford. These parameters varied over the years for each 

of the evaluated radionuclides, which included those of plutonium, americium, curium, tritium, 

uranium, strontium, promethium, polonium, neptunium, and fission products. This TBD discusses 

these issues in detail.

In addition, this TBD discusses the in vivo MDAs, the analytical methods, and the reporting protocols 

for the X- and gamma-ray emitting radionuclides. The in vivo measurement equipment and 

techniques were developed in the late 1950s and have been in routine use at Hanford since 1960. 

Detailed discussions are presented for the use of the whole-body counter, the radionuclides for which 

it was used, the radionuclide-specific MDAs, and the reporting levels for the various periods during 

which these parameters changed. There are similar discussions of the in vivo chest counters, thyroid 

counters, and head counters. Detailed information is provided in a database to assist the dose 

reconstructors in interpreting data they might encounter in the worker’s records.

The TBD discusses information on the specific radionuclides in each of the various facilities to which 

the workers 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 could 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 who could have been exposed, but for whom there are no confirmed intakes because of the 

detection capabilities or the sampling techniques used at the time or because there were missed 

samples. Methods for evaluating doses that could 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 Attachment D to aid the dose reconstructor in evaluating the potential 

doses received by workers under all circumstances. 

The Occupational External Dosimetry TBD (ORAUT 2004c) discusses the program for measuring skin 

and whole-body doses to the workers. As with internal dosimetry, the methods for evaluating external 

doses to workers have evolved over the years as new techniques and equipment have been 

developed and as the concepts in radiation protection have changed. The dose reconstruction 

parameters, Hanford practices and policies, and dosimeter types and technology for measuring the 

dose from the different types of radiation are discussed in this section. Attention is given to the 

evaluation of doses measured from exposure to beta, gamma, and neutron radiation. Tables show 

test results for various dosimeters 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 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. These potentially missed doses are discussed as a 

function of facility location, dosimeter type, year, and energy range. Attachment E to this TBD 

describes the use of the external dosimetry technical basis parameters to facilitate the efforts of the 

dose reconstructors.
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REFERENCES

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

Hanford Site – Site Description, ORAUT-TKBS-0006-2, Rev. 00 PC-1, Oak Ridge, Tennessee, 

December 29.

ORAUT (Oak Ridge Associated Universities Team), 2005, Hanford Site – Occupational Medical Dose, 

ORAUT-TKBS-0006-3, Rev. 01, Oak Ridge, Tennessee, April 11.

ORAUT (Oak Ridge Associated Universities Team), 2003, Technical Basis Document for the Hanford 

Site – Occupational Environmental Dose, ORAUT-TKBS-0006-4, Rev. 00, Oak Ridge, 

Tennessee, October 15.

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

Hanford Site – Occupational Internal Dose, ORAUT-TKBS-0006-5, Rev. 01, Oak Ridge, 

Tennessee, November 24.

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

Hanford Site – Occupational External Dosimetry, ORAUT-TKBS-0006-6, Rev. 01, Oak Ridge, 

Tennessee, January 9.