ORAU TEAM

Dose Reconstruction

Project for NIOSH

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

Page 1 of 9

Document Title:

K-25 Site – Introduction

Document Number: ORAUT-TKBS-0009-1

Revision: 01

Effective Date: 05/04/2006

Type of Document: TBD

Supersedes: Revision 00

Subject Expert: Paul A. Szalinski

Document Owner

Approval: Signature on File Approval Date: 04/19/2006

Paul A. Szalinski, TBD Team Leader

Approval: Signature on File Approval Date: 04/24/2006

John M. Byrne, Task 3 Manager

Concurrence: Signature on File Concurrence Date: 04/24/2006

Edward F. Maher, Task 5 Manager

Concurrence: Signature on File Concurrence Date: 04/18/2006

Kate Kimpan, Project Director

Approval: Signature on File Approval Date: 05/04/2006

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-0009-1 Revision No. 01 Effective Date: 05/04/2006 Page 2 of 9

PUBLICATION RECORD

EFFECTIVE 

DATE

REVISION

NUMBER DESCRIPTION

01/06/2004 00 New Technical Basis Document for the K-25 Site – Introduction. 

First approved issue. Initiated by Joseph Alvarez.

05/04/2006 01 Incorporates introductory language from NIOSH. Updates document 

for biennial review. No further changes resulted as a result of formal 

internal review. Incorporates NIOSH formal review comments. 

Approved issue of Revision 01. Training required: As determined by 

the Task Manager. Initiated by Jay J. Maisler.
Document No. ORAUT-TKBS-0009-1 Revision No. 01 Effective Date: 05/04/2006 Page 3 of 9

TABLE OF CONTENTS

SECTION TITLE

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

PAGE

4

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

1.1.1 Purpose.........................................................................................................................6

 1.1.2 Scope............................................................................................................................6

1.2 Site Description........................................................................................................................6

1.3 Occupational Medical Dose......................................................................................................6

1.4 Occupational Environmental Dose ...........................................................................................6

1.5 Occupational Internal Dose......................................................................................................7

1.6 Occupational External Dose.....................................................................................................7

References ..........................................................................................................................................9
Document No. ORAUT-TKBS-0009-1 Revision No. 01 Effective Date: 05/04/2006 Page 4 of 9

ACRONYMS AND ABBREVIATIONS

DOE U.S. Department of Energy

EEOICPA Energy Employees Occupational Illness Compensation Program Act

NIOSH National Institute for Occupational Safety and Health

TBD technical basis document

U.S.C. United States Code
Document No. ORAUT-TKBS-0009-1 Revision No. 01 Effective Date: 05/04/2006 Page 5 of 9

1.1 INTRODUCTION

Technical basis documents (TBDs) 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 in the event additional relevant information is obtained about the 

affected site(s). These documents may be used to assist the National Institute for Occupational 

Safety and Health (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 [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 [probability of causation] 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.

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 the facility 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:

• radiation from naturally occurring radon present in conventional structures;

• radiation from diagnostic X-rays received in the treatment of work-related injuries.
Document No. ORAUT-TKBS-0009-1 Revision No. 01 Effective Date: 05/04/2006 Page 6 of 9

1.1.1

This Site Profile can be a tool when performing dose reconstructions for K-25 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 K-25 exposure and 

dosimetry records.

Purpose

1.1.2

The Site Profile is divided into five major sections: Site Description, Occupational Medical Dose, 

Occupational Environmental Dose, Occupational Internal Dose, and Occupational External Dosimetry, 

in addition to this Introduction. 

Scope

1.2 SITE DESCRIPTION

The Site Description TBD (ORAU-TKBS-0009-2) contains a brief description of the facilities and 

processes used in the processing of uranium. The K-25 Site processed thousands of tons of uranium 

through diffusion cascades for more than 40 years beginning in February 1945. The vast majority 

was natural uranium from ore, but some was recycled material obtained from spent reactor fuel.

1.3 OCCUPATIONAL MEDICAL DOSE

The Occupational Medical Dose TBD (ORAU-TKBS-0009-3) provides information about the dose that 

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

included preemployment X-rays, annual chest X-rays during physical examinations, and health 

monitoring X-rays to determine the effects of inhalation of uranium. The frequency of required X-rays 

varied over time. All radiation workers received annual chest X-rays from 1944 through 1980, and

every 5 years after 1980. Nonradiation workers received annual chest X-rays until 1960, but none 

after 1960. Workers with a potential to inhale uranium dust might have had X-rays as frequently as 

monthly in 1944 and 1945, and bimonthly from 1946 to 1959.

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

this Site Profile. These factors were considered in estimating the dose that a worker would have 

received from the X-ray. Favorable assumptions were made to ensure that there was no 

underestimation of the worker’s dose if there was a doubt about the technique used. The parameters 

included tube current and voltage, exposure time, filtration, source-to-skin distance, view (posterioranterior or lateral), and any other factor that could affect the dose the worker received.

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

the uncertainty associated with each of the parameters mentioned above. The doses received by the 

organs in the body are listed in tables for convenient reference for dose reconstruction.

1.4 OCCUPATIONAL ENVIRONMENTAL DOSE

The Occupational Environmental Dose TBD (ORAU-TKBS-0009-4) applies to workers who were not 

monitored for external or internal radiation exposure. Workers received an environmental dose when 

working outside buildings on the site from inhalation of radioactive materials in the air, direct radiation 

from plumes, contact with particles on the skin, and direct exposure to radionuclides incorporated in 

the soil.
Document No. ORAUT-TKBS-0009-1 Revision No. 01 Effective Date: 05/04/2006 Page 7 of 9

Inhalation of environmental radionuclides results in internal dose to the whole body or body organs. 

Whole- or partial-body external dose results from deposited radionuclides or submersion in a cloud of 

radioactive material.

The internal dose for workers outside facilities was determined from air concentrations resulting from 

releases from stacks, individual building releases, and the purge cascade and other operations at 

K-25. Unmonitored workers could have been exposed to occupational doses internally from onsite 

releases to the air.

The air concentration of radionuclides was determined using use well-documented source terms 

developed for the Oak Ridge Dose Reconstruction (Burmeister 1996, 1997a,b) coupled with 

documented environmental monitoring data to estimate radionuclide-specific airborne concentrations 

for 234, 235, 238U, 238, 239, 240, 241, 242Pu, 237Np, and 99Tc (Shonka 2003). These radionuclides were 

determined to account for most of the potential missed dose from the inhalation and submersion 

pathways.

External doses to workers from onsite ambient radiation levels and from submersion in a cloud of 

radioactive material were estimated from onsite environmental dosimeters.

1.5 OCCUPATIONAL INTERNAL DOSE

The Occupational Internal Dosimetry TBD (ORAU-TKBS-0009-5) describes the internal dosimetry 

program at K-25. A bioassay program based on urinalysis for uranium started when K-25 began 

processing uranium. Urinalysis techniques used over the years followed the technology development 

for uranium detection. Urinalysis was preferred over in vivo techniques because in vivo minimum 

detectable activities were relatively high and thus of limited use for detecting uranium intakes. The 

processing of recycled uranium from spent reactor fuel introduced other radionuclides to K-25, in 

particular plutonium, americium, curium, neptunium, and 99Tc. These radionuclides were also best 

analyzed in urine. In general, the fraction of dose from these radionuclides in relation to uranium was 

very small and usually immeasurable if the uranium dose was small.

This TBD discusses interferences that might be encountered in the collection and analysis of bioassay 

samples and uncertainties in the bioassay measurements. It presents information that might be 

useful in estimating possible missed doses due to monitoring practices that were inadequate in 

comparison to modern standards. It also presents methods for evaluating potential doses that might

fall in this category.

1.6 OCCUPATIONAL EXTERNAL DOSE

The Occupational External Dosimetry Program TBD (ORAUT-TKBS-0009-6) discusses the program 

for measuring skin and whole-body doses to workers. It develops methods for evaluating external 

doses to workers that evolved as new techniques and equipment. Techniques changed as concepts 

in radiation protection changed. This TBD discusses dose reconstruction parameters, K-25 practices 

and policies, and dosimeter types and technology for measuring the doses from different types of 

radiation. It also discusses the evaluation of doses measured from exposure to beta, gamma, and 

neutron radiation.

This TBD discusses sources of bias, workplace radiation field characteristics, responses of different 

beta/gamma and neutron dosimeters in workplace fields, and adjustments to the recorded dose 

measured by dosimeters in specific years.
Document No. ORAUT-TKBS-0009-1 Revision No. 01 Effective Date: 05/04/2006 Page 8 of 9

Some sources of potential dose could be missed because of the limitations of dosimetry systems and 

the methods of reporting low doses. This TBD discusses missed dose as a function of dosimeter 

type, year, and type of radiation.
Document No. ORAUT-TKBS-0009-1 Revision No. 01 Effective Date: 05/04/2006 Page 9 of 9

REFERENCES

Burmeister, R. E., 1996, The Atmospheric Master Release List and Atmospheric Source Term for 

K-25, SRA 96-012, 

Burmeister, R. E., 1997a, 237Np and 99Tc Released to Air and Water from Historic Operations at the 

K-25 Site and Y-12 Sites, SRA-97-003, 

Burmeister, R. E., 1997b, Per Annum Atmospheric Releases of Uranium from the K-25 Site from 1944 

to 1995, SRA-97-011, 

Shonka, J., 2003, Calculations for the ORGDP Technical Basis Document (TBD) – Modified 

Atmospheric Master Routine List for ORGDP and Background Gamma Radiation, 

SRA 03-001,