ORAU Team

NIOSH Dose Reconstruction Project

Technical Basis Document for Hanford Introduction

Document Number:

ORAUT-TKBS-0006-1 

Effective Date: 01/09/2004

Revision No.: 01 

Controlled Copy No.: ______

Page 1 of 7

Subject Expert: Edward D. Scalsky 

Document Owner

Approval: Signature on File__________ _ Date: 01/09/2004

Edward D. Scalsky, TBD Team Leader

Approval: Signature on File ________ Date: 01/09/2004 Judson L. Kenoyer, Task 3 Manager

Concurrence: Signature on File ____ _ Date: 01/09/2004 Richard E. Toohey, Project Director

Approval: Signature on File ______ _ Date: 01/09/2004 James W. Neton, OCAS Health Science Administrator

Supersedes:

 Revision No.: 00

 TABLE OF CONTENTS

ACRONYMS

RECORD OF REVISIONS

1.0 INTRODUCTION
Effective Date: 01/09/2004 Revision No. 01 Document No. ORAUT-TKBS-0006-1 Page 2 of 7

RECORD OF ISSUE/REVISIONS

ISSUE 

AUTHORIZATION 

DATE

EFFECTIVE 

DATE

REV. 

NO. DESCRIPTION

11/07/03 11/07/2003 00 First approved issue. Initiated by Edward D. 

Scalsky.

Draft 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.

Draft 12/23/2003 01-B Incorporates OCAS comments. Initiated by 

Edward D. Scalsky.

01/09/2004 01/09/2004 01 Approved Issue of Revision 01. Initiated by 

Edward D. Scalsky.
Effective Date: 01/09/2004 Revision No. 01 Document No. ORAUT-TKBS-0006-1 Page 3 of 7

ACRONYMS

EEOICPA Energy Employees Occupational Illness Compensation Program Act of 2000

DOE U. S. Department of Energy

ORAU Oak Ridge Associated Universities

IREP Interactive RadioEpidemiological Program 

IMBA Integrated Modules for Bioassay Analysis

TBD Technical Basis Document

PUREX Plutonium-Uranium Extraction

REDOX Reduction/Oxidation

MDA minimum detectable activity 
Effective Date: 01/09/2004 Revision No. 01 Document No. ORAUT-TKBS-0006-1 Page 4 of 7

1.0 INTRODUCTION

In enacting the Energy Employees Occupational Illness Compensation Program Act of 2000 

(EEOICPA), the U.S. Congress officially recognized the hazardous nature of producing and testing 

nuclear weapons. Under the Act workers, who have developed selected types of cancer or their 

survivors may be entitled to compensation and medical benefits. This program is administered by the 

Department of Labor (DOL) Office of Worker Compensation (OWCP). The Department of Health and 

Human Service’s (HHS) National Institute for Occupational Safety and Health (NIOSH) is responsible 

for determining the individual worker’s dose.

Specifically the Act requires the estimation of radiological doses from ionizing radiation received by 

workers in the nuclear weapons production programs of the various U. S. Department of Energy 

(DOE) and its predecessor agencies. Methods for implementing provisions of the Act have been 

promulgated in 42 Code of Federal Regulations Part 82 (42CFR Part 82), “Methods for Radiation 

Dose Reconstruction Under the Energy Employees Occupational Illness Compensation Program Act 

of 2000” (Federal Register, Vol. 67 No. 85, Thursday, May 2, 2002).

Oak Ridge Associated Universities (ORAU) leads a team, the ORAU Team, to support NIOSH in 

conducting this major program. This Site Profile represents a specific support mechanism to the 

ORAU Team concerning documentation of historical practices at the Hanford Site. This Site Profile 

can be used to evaluate both internal and external dosimetry data for unmonitored and monitored 

workers and serve as a supplement to, or substitute for, individual monitoring data. This document 

provides a site profile of Hanford that contains technical basis information to be used by the ORAU 

Team to evaluate the total occupational radiation dose for EEOICPA claimants. 

This document also provides supporting technical data to evaluate, with claimant-favorable 

assumptions, the total Hanford occupational radiation dose that may 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 

on-site environmental releases. Also included is the dose that may have occurred while the worker 

was not monitored or the dose may have been missed. Over the years new and more reliable 

scientific methods and protection measures have been developed. The methods needed to account 

for these changes are also identified in this document. 

The doses are evaluated using the NIOSH Interactive RadioEpidemiological Program (IREP) and the 

Integrated Modules for Bioassay Analysis (IMBA) computer codes. Information on measurement 

uncertainties is an integral component of the NIOSH approach. This document describes how the 

uncertainty for Hanford exposure and dose records is evaluated.

The Site Profile is divided into five major Technical Basis Documents (TBDs); Site Description, 

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

Occupational External Dosimetry. Each TBD has an accompanying attachment that provides the 

critical data for the specialists reconstructing the doses. 

The Site Description TBD (ORAUT-TKBS-0006-2) presents a brief description of the facilities and 

processes that have been used in the development of nuclear weapons since the early 1940s.
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Beginning in 1944 nine reactors were operated to produce plutonium by the irradiation of metallic 

uranium fuel elements. In addition to the plutonium production, other defense-related radionuclides 

were experimented with, such as the irradiation of thorium to produce 233U, irradiation of depleted 

uranium to produce 240Pu, irradiation of neptunium targets to produce 238Pu, and irradiation of 

americium to produce medical grade 238Pu.

In addition to the production reactors, there were seven physical testing, research and demonstration 

reactors that were 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 space power systems.

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

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

physical processes that were performed in these canyons separated uranium, plutonium, and fission 

products. Specifically, plutonium was separated from the uranium and fission products by a bismuth 

phosphate precipitation batch process. Additional processing was done that 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 used organic solvent extraction processes. Each process improved the 

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

The U plant was another facility that was used for the recovery of uranium from high level liquid waste 

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.

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

i.e., 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.

Overall 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.

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

wastes produced in the various processes mentioned above.

The Occupational Medical Dose TBD (ORAUT-TKBS-0006-3) provides information about the dose 

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

X-rays included pre-employment and annual chest X-rays during their annual physical exams. The 

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

received annual chest X-rays from before 1946 through 1959. From April 12, 1959 through January 

28, 1983, workers over 50 years of age received annual X-rays, while workers in the 40-49 age group 
Effective Date: 01/09/2004 Revision No. 01 Document No. ORAUT-TKBS-0006-1 Page 6 of 7

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 

years of age received an X-ray biennially, the 40-49 age group, 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 were 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. When there was a doubt about the technique used, the 

most claimant favorable assumptions have been made to ensure the worker’s 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 received by the worker.

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

dose also takes into account the uncertainty associated with each of the parameters mentioned 

above. The doses received by the various organs in the body are presented in the tables for 

convenient reference by the dose reconstructors. .

The Occupational Environmental Dose TBD (ORAUT-TKBS-0006-4) applies to workers who were not 

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

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

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

radionuclides that may have become incorporated in the soil.

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

inhaling 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 in Hanford areas are based on the source terms developed by 

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

103Ru103Rh, 106Ru106Rh, 90Sr, 90Sr90Y contributed the greatest dose to site workers. The solubility of 

several of these radionuclides is also presented in this section.

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

computer program and an Excel spreadsheet. These data are presented in the tables in Attachment A 

of this section 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 Dosimetry TBD (ORAUT-TKBS-0006-5) discusses the internal dosimetry 

program that existed at the Hanford reservation. Initially (1943-1946) personnel monitoring was the 

responsibility of the Medical Department. At that time, there was no bioassay program in place to 

determine the internal dose workers may have received. Therefore claimant favorable assumptions 

have been made to provide the dose reconstructors with the ability to determine a worker’s dose in 

these early time periods. Later 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 used to identify the specific analysis 

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

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

years for each of the radionuclides evaluated, i.e., plutonium, americium, curium, tritium, uranium, 

strontium, promethium, polonium, neptunium, and fission products. This is discussed in great detail in 

this TBD.

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. Similar discussions are presented for the in vivo chest counters, thyroid 

counters and head counters.

Detailed information is provided in the database to assist the dose reconstructors in interpreting data 

they may encounter in the worker’s records.

Discussions are provided that provide information on the specific radionuclides that the workers in 

each of the various facilities may be exposed to. Information is also provided for the periods of time 

when processes changed as a result of improvements in the processing systems.

Interferences that may be encountered in the collection and analysis of bioassay samples are 

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

workers with no confirmed intakes, but who may have been exposed, as a result of the detection 

capabilities available or the sampling techniques used, or because there were missed samples.

Methods for evaluating potential doses that may 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-TKBS-0006-6) discusses the program for 

measuring skin and whole body doses to the workers. The methods for evaluating 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, 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. Test results are tabulated 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. This potentially missed dose is discussed as a 

function of facility location, dosimeter type, year, and energy range. Attachment E describes the use 

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