ORAU Team

NIOSH Dose Reconstruction Project

Technical Basis Document for the Rocky Flats Plant –

Introduction

Document Number:

ORAUT-TKBS-0011-1

Effective Date: 04/20/2004

Revision No.: 00

Controlled Copy No.: ________

Page 1 of 7

Subject Experts: Craig Little, Robert Meyer

Document Owner

Approval: Signature on File Date: 04/09/2004

Robert Meyer, TBD Team Leader

Approval: Signature on File Date: 04/14/2004

Judson L. Kenoyer, Task 3 Manager

Concurrence: Signature on File Date: 04/19/2004

Richard E. Toohey, Project Director

Approval: Signature on File Date: 04/20/2004

James W. Neton, OCAS Health Science Administrator

Supersedes:

None

TABLE OF CONTENTS

Section

Record of Issue/Revisions ...................................................................................................................

Page

2

Acronyms and Abbreviations ...............................................................................................................3

1.0 Introduction.................................................................................................................................4

Reference............................................................................................................................................7
Effective Date: 04/20/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-1 Page 2 of 7

RECORD OF ISSUE/REVISIONS

ISSUE 

AUTHORIZATION 

DATE

EFFECTIVE 

DATE

REV. 

NO. DESCRIPTION

Draft 02/18/2004 00-A New technical basis document for the Rocky 

Flats Plant – Introduction. Initiated by Robert 

Meyer.

Draft 04/02/2004 00-B Incorporates NIOSH review comments. Initiated 

by Robert Meyer.

Draft 04/09/2004 00-C Incorporates additional NIOSH review 

comments. Initiated by Robert Meyer.

04/20/2004 04/20/2004 00 First approved issue. Initiated by Robert Meyer.
Effective Date: 04/20/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-1 Page 3 of 7

ACRONYMS AND ABBREVIATIONS

CFR Code of Federal Regulations

DOE U. S. Department of Energy

DOL U.S. Department of Labor 

EEOICPA Energy Employees Occupational Illness Compensation Program Act of 2000

HHS U.S. Department of Health and Human Services

ICRP International Commission on Radiological Protection

IREP Interactive RadioEpidemiological Program 

IMBA Integrated Modules for Bioassay Analysis

MDA minimum detectable activity 

NIOSH National Institute for Occupational Safety and Health

ORAU Oak Ridge Associated Universities

OWCP Office of Worker Compensation 

PA posterior-anterior

RFP Rocky Flats Plant

TBD Technical Basis Document
Effective Date: 04/20/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-1 Page 4 of 7

1.0

The purpose of the Site Profiles is to assist with the evaluation of site-specific data in the dose 

reconstruction process. Each profile provides the rationale and historic background information 

required for dose reconstruction related to a particular site that participated in the manufacture or 

assembly of nuclear weapons or their components.

INTRODUCTION

Technical Basis Documents and Site Profile Documents are general working documents that provide 

guidance concerning the preparation of dose reconstructions at particular sites or categories of sites. 

They will be revised if additional relevant information is obtained about the affected site(s). These

documents may be used to assist NIOSH 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 facility” as defined in the Energy Employee 

Occupational Illness Compensation Program Act of 2000 (42 U.S.C. § 7384l (5) and (12)).

This Site Profile provides specific information concerning documentation of historical practices at the 

Rocky Flats Plant (RFP). Dose reconstructors can use this Site Profile to evaluate internal and 

external dosimetry data for unmonitored and monitored workers, and to serve as a supplement to, or 

substitute for, individual monitoring data. This document provides an RFP site profile that contains 

technical basis information the ORAU Team can use to evaluate the total occupational radiation dose 

for EEOICPA claimants.

In addition, this document also provides supporting technical data to evaluate, with claimant-favorable 

assumptions, the total RFP occupational radiation dose that can reasonably be associated with a

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

sources in RFP facilities, occupationally required diagnostic X-ray examinations, and onsite 

environmental releases. In addition, this document includes the dose that might have occurred while 

the worker was not monitored or the dose that might have been missed. Over the years new and 

more reliable scientific methods and protection measures have been developed. This document 

identifies methods needed to account for these changes. 

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

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

uncertainties is an integral component of the National Institute for Occupational Safety and Healh 

(NIOSH) approach. This document describes the evaluation of uncertainty for RFP exposure and 

dose records.

The Site Profile consists of five major technical basis documents (TBDs): Site Description, 

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

Occupational External Dosimetry. The TBDs may have attachments to provide detailed information

for the specialists reconstructing the doses. 

The Site Description TBD (ORAUT-TKBS-0011-2) describes RFP facilities and processes used in the 

development of nuclear weapons since the early 1940s. RFP operations played an important role in 

the U.S. nuclear weapons program; these operations included production of weapons components. 

This TBD contains documentation to assist in the evaluation of worker dose from RFP operations and 

processes.
Effective Date: 04/20/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-1 Page 5 of 7

In March 1951, the U.S. Atomic Energy Commission announced its decision to build the Rocky Flats 

Plant in Colorado, and groundbreaking occurred in July 1951. From the beginning, the plant was a 

manufacturing facility. The primary mission and general activities at the plant remained essentially 

the same from the time the plant opened until 1989, when DOE suspended plutonium operations. 

RFP had two major missions – production of plutonium triggers (or “pits”) for nuclear weapons, and 

processing of weapons for plutonium recovery. Early designs that were solid units made mostly of 

uranium gave way to a plutonium pit design in the mid-1950s. Plutonium pits or triggers are

components of fission bombs, and can be used to initiate the second-stage fusion reaction in 

hydrogen bombs. Plutonium was received from the Savannah River and Hanford production sites,

and from retired warheads and residues. 

Parts were formed and machined from plutonium, uranium, beryllium, stainless steel, and other 

materials. Plutonium and uranium recovery and waste handling facilities were present on the site to 

handle radioactive wastes produced in these processes.

The Occupational Medical Dose TBD (ORAUT-TKBS-0011-3) provides information about doses

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

Entrance, exit, and periodic physical examinations were performed on all employees as part of the 

requirements for employment at RFP. These examinations could include radiographic examinations 

of the lungs and, for some employees, possible radiographs of the lumbar spine. 

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

takes into account the uncertainty associated with machine type, exam frequency and job 

classification. This TBD presents doses received by the various organs in the body in tabular form for 

convenient reference by dose reconstructors.

The Occupational Environmental Dose (described in TBD ORAUT-TKBS-0011-4) is the dose workers 

receive when working outside buildings, from inhalation of or direct exposure to radioactive materials 

in the air, and from direct exposure to radionuclides that might 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 radioactive materials, or could result in a whole- or partial-body external dose from deposited 

radionuclides or submersion in a cloud of radioactive material. Although plutonium (239/240Pu, 241Pu) is 

the primary material of concern for offsite exposures, tritium, natural thorium, enriched uranium, 

depleted uranium and Americium-241 (241Am) were the radionuclides of concern identified in historical 

public exposure studies, and were the significant radionuclides encountered in the environment by 

site workers. 

External doses to workers from onsite ambient radiation levels are determined from measurements 

reported in and estimated from site annual environmental reports.

The Occupational Internal Dosimetry TBD (ORAUT-TKBS-0011-5) discusses the RFP internal 

dosimetry program, and develops estimates of potential intakes. Workers at RFP had the potential to 

take in plutonium, americium, enriched uranium, depleted uranium, and tritium, as well as smaller 

quantities of other radionuclides. This TBD describes available source term information, including 

isotopic composition, solubility and particle size for plutonium, americium, enriched uranium, depleted 

uranium, and tritium (

3

H). Site-specific internal dosimetry information for other radionuclides, such as 

thorium, curium and neptunium, is either rare or not available. 

Primary modes of intake were chronic or acute inhalation or through breaks in the skin (wounds). 

Bioassay data estimate radionuclide activity excreted in the urine following an inhalation or wound 
Effective Date: 04/20/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-1 Page 6 of 7

intake. Lung count data estimate the radionuclide present in the lungs after an inhalation intake. The 

TBD discusses these two data sets in detail, including history, sensitivity, and pertinent nuances of 

methods and data.

The internal exposure record for a specific worker consists of records of his/her bioassay data, and 

reports of involvement in incidents, accidents, or special situations. This TBD examines samples of 

records and reports, providing explanations of aspects and terms important to dosimetry.

The TBD discusses minimum detectable activities (MDAs), the analytical methods and reporting 

protocols related to urinalysis methods for the radionuclides encountered at RFP. Such parameters 

changed over the years for each radionuclide evaluated (i.e., plutonium, americium, curium, tritium, 

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

details of these variables.

The TBD also discusses minimum detectable activities (MDAs), analytical methods, and reporting 

protocols for in vivo lung counts for X- and gamma-ray-emitting radionuclides. Such in vivo

measurement equipment and techniques, which were developed in the late 1950s, have been in 

routine use at RFP since 1964. The TBD contains a detailed discussion of the lung counter, including 

241Am-specific MDAs and reporting levels for the various periods during which these parameters 

changed. It provides detailed information to assist dose reconstructors in interpreting data they might 

encounter in worker records.

The Occupational External Dosimetry TBD (ORAUT-TKBS-0011-6) describes the methods and 

concepts of measuring occupational external dose to workers, and how the methods have evolved 

since the beginning of RFP operations. It provides supporting technical data to evaluate, with 

claimant-favorable assumptions, external RFP occupational doses that can reasonably be associated 

with worker radiation exposures covered under the EEOICPA. These doses include occupational 

external exposures in RFP facilities, and onsite exposures to RFP environmental releases. The TBD 

evaluates unmonitored and monitored worker exposure, and missed dose. Consistent with NIOSH 

Implementation Guidelines, it provides guidance on the adjustment of occupational external recorded 

dose to parallel current scientific methods and protection factors. 

In addition, this TBD presents the technical basis for methods used to prepare RFP worker external 

dose records for input to the NIOSH IREP system used to evaluate worker dose. Information on 

measurement uncertainties is an integral component of the NIOSH approach. This TBD describes the 

evaluation of uncertainty for RFP exposure records. 

In summary: all five technical TBDS for the Rocky Flats Plant provide detailed information, data, 

explanations, and references for use during the reconstruction of RFP worker doses. In addition, the 

Rocky Flats TBD Users Guide will combine key data from each TBD, to create a single document 

allowing more efficient use of the information by dose reconstructors.
Effective Date: 04/20/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-1 Page 7 of 7

REFERENCE

ICRP (International Commission for Radiological Protection), 1996, Age-Dependent Doses to 

Members of the Public from Intake of Radionuclides: Part 5, Compilation of Ingestion and 

Inhalation Coefficients, Publication 72, Pergamon Press, Oxford, England.