May 31, 2007 

Mr. David Staudt 

Center for Disease Control and Prevention 

Acquisition and Assistance Field Branch 

Post Office Box 18070 

626 Cochrans Mill Road – B-140 

Pittsburgh, PA 15236-0295 

Re: Contract No. 200-2004-03805, Task Order 1: Transmittal of Draft SCA-TR-TASK1-0017, 

K-25 Gaseous Diffusion Plant Site Profile Review 

Dear Mr. Staudt: 

SC&A, Inc. is please to submit its draft report titled K-25 Gaseous Diffusion Plant Site Profile 

Review, SCA-TR-TASK1-0017. This report was submitted for Privacy Act (PA) review on 

March 9, 2007, and has been revised to accommodate that review. This report is considered predecisional and is being submitted to the Advisory Board for review. 

Should you have any questions, please contact me at 732-530-0104. 

Sincerely, 

John Mauro, PhD, CHP 

Project Manager 

cc: P. Ziemer, PhD, Board Chairperson A. Makhijani, PhD, SC&A 

Advisory Board Members H. Behling, SC&A 

L. Wade, PhD, NIOSH M. Thorne, SC&A 

L. Elliott, NIOSH H. Chmelynski, SC&A 

J. Neton, PhD, NIOSH J. Fitzgerald, Saliant 

S. Hinnefeld, NIOSH J. Lipsztein, SC&A 

L. Homoki-Titus, NIOSH K. Robertson-DeMers, CHP, Saliant 

A. Brand, NIOSH S. Ostrow, PhD, SC&A 

J. Broehm, NIOSH K. Behling, SC&A 

L. Shields, NIOSH T. Bell, Saliant 

Project File (ANIOS/001/17) 

1608 SPRING HILL ROAD, SUITE 400 • VIENNA, VIRGINIA • 22182 • 703.893.6600 • FAX 703.821.8236 
 

Draft 

ADVISORY BOARD ON 

RADIATION AND WORKER HEALTH 

National Institute for Occupational Safety and Health 

K-25 Gaseous Diffusion Plant Site Profile Review 

Contract No. 200-2004-03805 

Task Order No. 1 

SCA-TR-TASK1-0017
 

Prepared by 

S. Cohen & Associates 

1608 Spring Hill Road, Suite 400 

Vienna, Virginia 22182 

Saliant, Inc.
 

5579 Catholic Church Road 

Jefferson, Maryland 21755
 

May 2007 

Disclaimer 

This document is made available in accordance with the unanimous desire of the Advisory Board 

on Radiation and Worker Health (ABRWH) to maintain all possible openness in its 

deliberations. However, the ABRWH and its contractor, SC&A, caution the reader that at the 

time of its release, this report is pre-decisional and has not been reviewed by the Board for 

factual accuracy or applicability within the requirements of 42 CFR 82. This implies that once 

reviewed by the ABRWH, the Board’s position may differ from the report’s conclusions. Thus, 

the reader should be cautioned that this report is for information only and that premature 

interpretations regarding its conclusions are unwarranted. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

2 of 191 

 

S. Cohen & Associates: Document No. 

SCA-TR-TASK1-0017 

Technical Support for the Advisory Board on 

Radiation and Worker Health Review of 

Effective Date: 

Draft — May 31, 2007 

NIOSH Dose Reconstruction Program Revision No. 

0 – DRAFT 

K-25 GASEOUS DIFFUSION PLANT SITE 

PROFILE REVIVEW 

Page 1 of 191 

Task Manager: 

________________________ Date: ___________ 

Joseph Fitzgerald 

Supersedes: 

N/A 

Project Manager: 

________________________ Date: ___________ 

John Mauro 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker
 

Health for factual accuracy or applicability within the requirements of 42 CFR 82.
 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

3 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

TABLE OF CONTENTS 

Acronyms and Abbreviations ..........................................................................................................5 

1.0 Executive Summary.............................................................................................................9 

1.1 Summary of Strengths............................................................................................11 

1.2 Summary of Findings.............................................................................................12 

1.2.1 Primary Findings........................................................................................12 

1.2.2 Secondary Findings....................................................................................15 

1.3 Opportunities for Improvement .............................................................................16 

2.0 Scope and Introduction ......................................................................................................20 

2.1 Review Scope.........................................................................................................20 

2.2 Review Approach...................................................................................................21 

2.3 Report Organization...............................................................................................22 

3.0 Assessment Criteria and Methods......................................................................................24 

3.1 Objectives ..............................................................................................................24 

3.1.1 Objective 1: Completeness of Data Sources.............................................24 

3.1.2 Objective 2: Technical Accuracy..............................................................24 

3.1.3 Objective 3: Adequacy of Data.................................................................25 

3.1.4 Objective 4: Consistency among Site Profiles..........................................25 

3.1.5 Objective 5: Regulatory Compliance........................................................25 

4.0 Site Profile Strengths .........................................................................................................29 

4.1 Internal Dose TBD Strengths.................................................................................29 

4.2 External Dose TBD Strengths................................................................................29 

4.3 Medical Dose Strengths .........................................................................................30 

4.4 Environmental Dose TBD Strengths .....................................................................30 

5.0 Vertical Issues....................................................................................................................31 

5.1 Issue 1: More Guidance is Needed on Appropriate Enrichment when 

interpreting Uranium Bioassay Mass Concentration Data.....................................31 

5.2 Issue 2: No Default Absorption (Solubility) Classes for Any of the Intakes 

are Identified ..........................................................................................................32 

5.3 Issue 3: The Default Isotopic Distribution does Not Appear to be Claimant 

Favorable................................................................................................................34 

5.4 Issue 4: There is General Inconsistency or Lack of Complete Radionuclide 

Information for Facilities in the TBD Tables ........................................................35 

5.5 Issue 5: Lack of Incident Information May be a Problem for Accuracy and 

Claimant-Favorable Internal Dose Reconstruction................................................36 

5.6 Issue 6: Coworker Data Use and Approach for Unmonitored Employees 

May not be Appropriate.........................................................................................37 

5.7 Issue 7: Uranium Cylinder Storage Yard Dose May be Underestimated and 

Neutron Dose May have been Missed ...................................................................39 
 

 

Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

4 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

5.8 Issue 8: Until 1980, Some dosimeters were only processed upon request 

resulting in ambiguity regarding the construction of doses in the early years.......40 

5.9 Issue 9: Chronic Neutron Exposure Opportunities May have been 

Overlooked.............................................................................................................40 

5.10 Issue 10: Potential Exposure to Tc-99 Beta were Not Recorded by 

Dosimeters and are Not Addressed in the TBD.....................................................41 

5.11 Issue 11: Reliance on a Single Neutron-to-Photon Ratio for the Entire Plant 

is Questionable.......................................................................................................42 

5.12 Issue 12: All Beta Dosimetry was based on a Uranium Slab Calibration ............42 

5.13 Secondary Issues....................................................................................................43 

5.13.1 Secondary Issue 1: There is a Lack of Guidance on Bioassay 

Interpretation..............................................................................................43 

5.13.2 Secondary Issue 2: There is No Comparison between Measured 

and Predicted Environmental Dose............................................................45 

5.13.3 Secondary Issue 3: The TBDs do not provide a Consistent Time
 

Period for the Processing of RU at K-25. ..................................................45 

5.13.4 Secondary Issue 4: The TBD Does Not Adequately Define 

Frequency and Assess All Types of X-rays in Occupational Medical 

Exposure. ...................................................................................................46 

5.13.5 Secondary Issue 5: Techniques and Protocols Increase Uncertainty 

of Dose Conversion Factors Listed in the TBD.........................................48 

5.14 Review of Technical Support Documents .............................................................50 

5.14.1 Review of Internal Coworker Data for K-25, ORAUT-OTIB-0035 .........50 

5.14.2 Review of External Dosimetry Coworker Data for K-25, ORAUTOTIB-0026.................................................................................................52 

6.0 Overall Adequacy of the Site Profile as a Basis for Dose Reconstruction ........................54 

6.1 Satisfying the Five Objectives ...............................................................................54 

6.1.1 Objective 1: Completeness of Data Sources.............................................54 

6.1.2 Objective 2: Technical Accuracy..............................................................55 

6.1.3 Objective 3: Adequacy of Data.................................................................57 

6.1.4 Objective 4: Consistency among Site Profiles..........................................58 

6.1.5 Objective 5: Regulatory Compliance........................................................61 

6.2 Usability of Site Profile for Intended Purposes .....................................................61 

6.2.1 Ambiguous Dose Reconstruction Direction ..............................................62 

6.2.2 Inconsistencies and Editorial Errors in the Site Profiles............................62 

6.3 Unresolved Policy or Generic Technical Issues ....................................................62 

References......................................................................................................................................64 

Attachment 1: NIOSH Technical Documents Considered During the Review Process...............70 

Attachment 2: Site Expert Interview Summary............................................................................72 

Attachment 3: Key Questions and Responses for NIOSH/ORAU Regarding Site Profile 

Documents .......................................................................................................................134 

Attachment 4: Summary of Conference Calls on SC&A Questions Provided to NIOSH..........164 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

5 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

ACRONYMS AND ABBREVIATIONS 

Advisory Board Advisory Board on Radiation and Worker Health 

AEC Atomic Energy Commission 

ALARA As Low as Reasonably Achievable 

ANALIS Old Environmental Management Laboratory Information System Database 

AMAD Activity Median Aerodynamic Diameter 

ANSI American National Standards Institute 

ASA Accelerated Safety Analysis 

ASER Annual Site Environmental Report 

AVLIS Atomic Vapor Laser Isotope Separation 

BJC Bechtel Jacobs Company, LLC 

BNFL British Nuclear Fuels Limited 

Bq Becquerel 

BWXT BWX Technologies Company 

CBD Chronic Beryllium Disease 

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act 

CFR Code of Federal Regulations 

Ci Curie 

CIP Cascade Improvement System 

C&S An Oak Ridge, Tennessee Laundry Company 

CUP Cascade Upgrade Program 

DAC Derived Air Concentration 

DCF Dose Conversion Factor 

DCG Decontamination Guidelines 

D&D Decontamination and Decommissioning 

DOD Department of Defense 

DOE Department of Energy 

DOELAP Department of Energy Laboratory Accreditation Program 

DOL Department of Labor 

dpm Disintegrations per Minute 

DR Dose Reconstruction 

DRs Dose Reconstructors 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

6 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRS Dose Reconstruction System 

EEOICPA Energy Employees Occupational Illness Compensation Program Act of 2000 

ECG Electrocardiogram 

EMWMF DOE Environmental Management Waste Management Facility 

EOC Emergency Operations Center 

EPA United States Environmental Protection Agency 

ESE Entrance Skin Exposure 

ETTP East Tennessee Technology Park (Formerly the K-25 Site) 

FSR Facility Safety Representative 

GSD Geometric Standard Deviation 

HEU Highly Enriched Uranium 

HHE Health Hazards Evaluation 

HP Health Physics Group 

HPSO Health Physics and Safety Organization 

HVL Half Value Layer 

ICATS Information Corrective Actions Tracking System 

ICRP International Commission on Radiological Protection 

IH Industrial Hygiene Group 

IMBA Integrated Modules for Bioassay Analysis 

INEEL Idaho National Engineering and Environmental Laboratory 

keV Kilo electron Volt 

KOH Potassium Hydroxide 

LANL Los Alamos National Laboratory 

LAT Lateral Chest X-ray 

LLD Lower Limit of Detection 

LPT Lymphocyte Proliferation Testing 

μCi Microcurie 

MCW Mallinckrodt Chemical Works 

MDA Minimum Detectable Activity 

MDC Minimum Detectable Concentration 

MDL Minimum Detectable Level 

MeV Million-electron Volt 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

7 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

MMC Oak Ridge Methodist Medical Center 

MPC Maximum Permissible Concentration 

mR Milliroentgen 

mrem Millirem 

NCRP National Council on Radiation Protection and Measurements 

NESHAP National Emission Standards for Hazardous Air Pollutants 

NDA Non-Destructive Testing 

NIOSH National Institute for Occupational Safety and Health 

NPDES National Pollutant Discharge Elimination System 

NRC United States Nuclear Regulatory Commission 

NTA Eastman Kodak Nuclear Track Film Type A 

NTS Nevada Test Site 

OCAS Office of Compensation Analysis and Support 

ORNL Oak Ridge National Laboratory 

ORAU Oak Ridge Associated Universities 

ORGDP Oak Ridge Gaseous Diffusion Plant 

ORR Oak Ridge Reservation 

OTIB ORAU Technical Information Bulletin 

PA Posterior-Anterior Chest X-ray 

PACE PACE Local 5-288 and International Union 

PCB Polychlorinated Biphenyls 

PCM Personnel Contamination Monitor 

PEMS Paducah Project Environment Management System 

PDD Paducah Daily Distributed Newsletter 

PFG Photofluorography 

PGDP Paducah Gaseous Diffusion Plant 

PHS Preliminary Hazards Screening 

PIC Pocket Ionization Chamber 

PNAD Personal Neutron Accident Dosimeter 

POC Probability of Causation 

PPE Personal Protective Equipment 

ppm Parts Per Million 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

8 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

PSS Plant Shift Supervisor 

QA Quality Assurance Group 

R&D Research and Development 

RCP Radiological Control Permit 

RCT Radiological Control Technician 

RCW Radioactively Contaminated Waste 

RCRA Resource Conservation and Recovery Act 

RFP Rocky Flats Plant 

RPP Radiation Protection Permit 

RU Recycled Uranium 

RWP Radiation Work Permit 

SC&A S. Cohen and Associates 

SEC Special Exposure Cohort 

SP Security Policeman 

SRS Savannah River Site 

SWP Special Work Permit 

TBD Technical Basis Document 

TCE Trichloroethylene 

TDEC Tennessee Department of Environment and Conservation 

TIB NIOSH Technical Information Bulletin 

TLD Thermoluminescent Dosimeter 

TOXCO Tennessee Reindustrialization Tennant Company 

TRU Transuranics 

TSCA Toxic Substances Control Act 

TSR Technical Safety Review 

UCC Union Carbide Corporation 

UMTRA Uranium Mill Tailings Remedial Action Program 

USEC USEC, Inc., A Global Energy Company 

UT-B ORNL University of Tennessee – Battelle Company 

Y-12 Y-12 National Security Complex 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

9 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

1.0 EXECUTIVE SUMMARY 

This report provides the results of an independent audit conducted by S. Cohen and Associates 

(SC&A, Inc.) of the Technical Basis Documents (TBDs) that make up the site profile developed 

by the National Institute for Occupational Safety and Health (NIOSH) for the Oak Ridge K-25 

Gaseous Diffusion Plant Site. This audit was conducted during the period of October 3, 2006– 

February 22, 2007, in support of the Advisory Board on Radiation and Worker Health (Advisory 

Board) in the latter’s statutory responsibility under the Energy Employees Occupational Illness 

Compensation Program Act of 2000 (EEOICPA) to conduct such reviews and advise the 

Secretary of Health and Human Services on the “completeness and adequacy” of the EEOICPA 

program. 

The Oak Ridge K-25 Gaseous Diffusion Plant Site (K-25 Site) is owned by the U. S. Department 

of Energy (DOE) and played an important role in the U.S. nuclear weapons program. It is 

currently known as the East Tennessee Technology Park (ETTP). The K-25 Site processes 

included uranium enrichment (U-235), radiochemical processing, uranium recycling, and waste 

management. The dates of operation of the K-25 facilities and activities are summarized in the 

K-25 Site Description TBD, ORAUT-TKBS-0009-2 (Szalinski 2006b), and as the TBD explains, 

are based on information from Recycled Uranium Mass Balance Project, Oak Ridge Gaseous 

Diffusion Plant (Currently Known as East Tennessee Technology Park) Site Report (BJC and 

Haselwood Enterprises 2000). 

The Site Description TBD (Szalinski 2006b) provides the following summary of the scope of the 

nuclear activities conducted at the K-25 Site: 

The K-25 Site, now known as the East Tennessee Technology Park (ETTP), 

processed thousands of tons of uranium through diffusion cascades for more than 

40 years. The vast majority of the uranium was extracted and purified from ore, 

but some was recycled material obtained from spent reactor fuel. 

The primary K-25 areas that enriched 235U using the gaseous diffusion process 

include Cascade Buildings K-25, K-27, K-29, K-31, K-33, K-413, and K-631. 

Uranium was initially processed in series operation in Buildings K-25, K-27, and 

K-29. Buildings K-31 and K-33 were later placed in series operations with the 

existing cascade. When the enrichment process was active, the uranium in these 

areas was almost exclusively in the form of uranium hexafluoride (UF6). 

The uranium processed in these areas originated both from natural ores and 

recycled uranium products. The uranium feed materials, whether natural or 

recycled uranium, were purified before reaching K-25 and were chemically 

identical. Various natural sources were used but the uranium feed material was 

not source-dependent. The recycled uranium contained trace amounts of 

activation and fission products that were not completely removed by the recovery 

and purification processes. The recycled feed material could have varied 

somewhat depending upon both time in the reactor and process of recovery. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

10 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Processing of recycled uranium from spent reactor fuel was intermittent, with 

campaigns conducted in 1952 to 1964, 1969 to 1974, and 1976 and 1977. 

Virtually all of the recycled uranium came from plutonium production reactors at 

the Hanford and Savannah River Sites, with little from power or demonstration 

reactors. 

The material recycled from reprocessed reactor fuels contained trace quantities 

of fission products and transuranic (TRU) elements formed during irradiation of 

the fuels. Most of these impurities were removed during chemical processing of 

the fuels. Because fluorinated compounds of the elements in question have 

limited volatility, much of the impurity activity initially present remained in the 

feed cylinders or was deposited in the cascade equipment very close to the feed 

point. However, trace quantities passed through the chemical and physical 

separations to contaminate the diffusion cascades. Process operations primarily 

resulted in 234U, 235U, and 238U contamination. Characterization of the recycled 

uranium included in the Recycled Uranium Mass Balance Project Oak Ridge 

Gaseous Diffusion Plant Site Report indicate the primary contaminants incident 

to the recycled uranium are technetium-99 (99Tc), neptunium-237 (237Np), 

americium-241 (241Am), plutonium-238 (238Pu), and 239/240Pu (Szalinski 2006b, 

pp. 6–7). 

SC&A’s review focused on the six TBDs that make up the K-25 Site Profile. These address 

Introduction, Site Description, Internal Dose, External Dose, Occupational Medical Dose, and 

Occupational Environmental Dose, as they pertain to historic occupational radiation exposure to 

K-25 workers. As “living” documents, TBDs are constantly being revised as new information, 

experience, or issues arise. For the K-25 Site Profile, in particular, interviews with NIOSH and 

ORAU staff underscored their ongoing and extensive efforts to upgrade the existing TBDs. In 

that context, SC&A discussed with NIOSH (and ORAU) the latter’s dose estimation guidance 

for K-25 that may figure in their next TBD revision and would supersede earlier site profile 

direction. That discussion is reflected in several of the SC&A findings in order to add an 

updated perspective of how NIOSH plans to address these issues (notwithstanding that the 

SC&A review remains based on the current TBD editions). 

SC&A’s review process included a review of the TBDs, one onsite visit to conduct interviews 

with site experts and identify documents for data retrieval, reviews of retrieved K-25 and other 

historic records, and an exchange of questions and answers, in addition to TBD-specific 

conference calls, between SC&A and its NIOSH and ORAU counterparts. The TBDs were 

evaluated for their completeness, technical accuracy, adequacy of data, compliance with stated 

objectives, and consistency with other site profiles, as stipulated in the SC&A Standard 

Operating Procedure for Performing Site Profile Reviews (SC&A 2004). A complete list of the 

K-25 TBDs, as well as supporting documents, that were reviewed by SC&A is provided in 

Attachment 1. 

The Site Description TBD states that, along with uranium enrichment, recycling, and waste 

management, there was radiochemical processing; however, there is little information provided 

covering this or any special research or programs that may have used sources other than the 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

11 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

traditional uranium source terms it describes. Comments have been made at a project meeting 

with former employees that K-25 had other programs that involved radionuclide sources that 

were different than the uranium fuel mixtures (NIOSH 2005). There is also some inconsistency 

in the TBDs regarding the time periods of processing recycled uranium (RU) (the site description 

states in one section that 1977 and in another section that 1984 was the end of processing RU; 

the internal dosimetry description states that it was 1976). 

The site profile does not address occupational radiation sources beyond the more established and 

well-documented ones. This is potentially problematic, given the radiological significance of 

many of these “other” radionuclides, the steadily evolving nature of radiological controls, 

dosimetry practices, and recordkeeping at the site through the late 1940s, 1950s, 1960s, and into 

the 1970s, and the lack of individual specific radiological monitoring and dose data that may 

have contributed to information gaps critical to dose estimation. 

The Site Description and Internal Dose TBDs do not consistently identify all potentially 

important radionuclides in the source terms (Pu-241 and U-236 are not identified in the Site 

Description TBD; Th-230, Am-241, Cm-242, and Cm-244 are not identified in the source terms 

listed for specific buildings in the internal dosimetry TBD). There is no discussion on the 

contamination levels (air and surface contamination) that could have been involved with 

exposures at the site. Radiological controls, such as source containment, air-monitoring data, 

respiratory protection usage, and surface contamination monitoring and the changes in these 

practices as the site progressed were not covered in the TBDs. 

Issues presented in this report are sorted into the following categories, in accordance with 

SC&A’s review procedures: 

(1) Completeness of data sources 

(2) Technical accuracy 

(3) Adequacy of data 

(4) Consistency among site profiles 

(5) Regulatory compliance 

Following the introduction and a description of the criteria and methods employed to perform the 

review, the report discusses the strengths of the TBD, followed by a description of the major 

issues identified during our review. The issues were carefully reviewed with respect to the five 

review criteria. Several of the issues were designated as primary findings, because they 

represent key deficiencies in the TBDs that need to be corrected, and which have the potential to 

substantially impact at least some dose reconstructions. Others have been designated “secondary 

findings” to both connote their importance for the technical adequacy and completeness of the 

site profile, and to indicate that they have been judged by SC&A to have relatively less influence 

on dose reconstruction or the ultimate significance of worker doses estimated. 

1.1 SUMMARY OF STRENGTHS 

The K-25 Occupational Environmental TBD, ORAUT-TKBS-0009-4 (East 2006), describes the 

potential exposures from ambient sources to unmonitored workers while outside the facilities. 

The document presents data for estimating annual intakes from radionuclides in air and external 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

12 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

dose from ambient radiation, as well as from cylinder storage yards. The TBD provides 

references to numerous environmental reports for the site. 

The K-25 Occupational Internal Dose TBD, ORAUT-TKBS-0009-5 (Thomas 2006), identifies 

that interpretation of bioassay data can be difficult, due to uncertainty regarding enrichment, 

solubility, and the contribution of environmental uranium. It also identifies intakes that could 

involve soluble and insoluble fractions, which could complicate interpretation. This TBD also 

states that samples were collected at work, so cross-contamination could contribute to 

uncertainty. The K-25 Site Description TBD, ORAUT-TKBS-0009-2 (Szalinski 2006b) 

provides numerous examples of the varying uranium to transuranic radionuclide (U:TRU) and 

uranium to technetium-99 (U:Tc) ratios that could have occurred at the site, which can help 

internal dose assessment. 

1.2 SUMMARY OF FINDINGS 

1.2.1 Primary Findings 

Finding 1: More guidance is needed on appropriate enrichment assumptions when 

interpreting uranium bioassay mass concentration data. The K-25 Occupational Internal 

Dose TBD (Thomas 2006) needs to provide more guidance on the appropriate enrichment to 

assume when interpreting uranium bioassay mass concentration data, and the enrichment 

assumed for the default isotopic distribution may not be appropriate or claimant favorable. 

Finding 2: No default absorption (solubility) classes for any of the intakes are identified. 

Absorption classes for two important forms of uranium (UO3 and U3O8) listed are incorrect. 

There is no discussion on high-fired uranium oxides or Special Class Y (S) material that would 

have different biokinetics than traditional Class S uranium compounds 

Finding 3: The default isotopic distribution does not appear to be claimant favorable. It 

does not contain Pu-238, Pu-240, Pu-241, and Pu-242; Cm-242 and Cm-244; assumes only low 

enriched (2%) uranium; and the Tc-99 ratio is questionably low. The Site Description, as well as 

the Internal Dose TBD, describe the use of higher enrichments and identify 3% as the 

predominant enrichment at the site, as discussed in the finding above, along with the fact that 

higher enrichment would lead to higher activity intakes and doses when interpreting uranium 

urine mass concentrations. There needs to be a strong justification for the assumptions regarding 

enrichment, as adopted by NIOSH, because they do not appear to be claimant favorable or 

correct. 

Finding 4: The TBD is inconsistent or lacks complete information on radionuclides for 

K-25 facilities. There is a general inconsistency or lack of complete radionuclide guidance and 

information for facilities shown in the tables of the TBD. Several major radionuclides are not 

shown in source terms at various buildings in Table 5-4 (Thomas 2006), Source Term Summary 

by Location. Table 5-2, principal radionuclides found at uranium facilities and gaseous diffusion 

plants, list Th-230, Am-241, Cm-242, and Cm-244, and the default isotopic distribution in 

Table 5-6 lists Th-230 and Am-241, yet these radionuclides are not shown as part of the source 

term in any buildings listed in Table 5-4. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

13 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Finding 5: Lack of information regarding incidents may be a problem for accurate and 

claimant-favorable internal dose reconstructions. The lack of information on incidents that 

could have caused significant intakes of radionuclides could hinder accurate interpretation of 

bioassay results and identification of intakes by unmonitored or inadequately monitored workers. 

There are no incidents identified in this TBD. There were likely several incidents which have 

incident investigation information that would help dose reconstructors perform accurate and 

claimant favorable intake and dose assessments. Interpretation of bioassay data can be assisted 

by the use of incident records information and, if no bioassay data are available for an 

unmonitored or inadequately monitored claimant that may have been involved in an incident, 

then other types of data from the investigation may be used for dose assessment. 

Finding 6: Coworker data use and approach for unmonitored employees may not be 

appropriate or claimant favorable. NIOSH’s use of the median bioassay data values from 

1948 to 1988 for uranium intake rates and 1978 to 1988 data for Tc-99 intake rates may not be 

reasonable or claimant favorable for several reasons. Because there was undoubtedly some 

variation of intake rates around the median values, it does not appear to be claimant favorable to 

assume that a claimant’s intake was a median intake, as opposed to a higher value such as the 

84th percentile value. NIOSH needs to determine if the work processes (such as production 

level/throughput), exposure conditions, and radiological controls (engineering, administrative, 

personal protective equipment (PPE)) for the 1945–1947 period were similar to the periods that 

followed it. 

Finding 7: Uranium cylinder storage yard dose may be underestimated. Section 6.7.3 of 

the Occupational External Dose TBD (Miles 2006) states that the neutron dosimeters in use 

“were generally insensitive to the low neutron dose rates at K-25...” In addition, as discussed 

elsewhere in this review, the dosimeters were insensitive to any dose rate due to neutrons below 

the NTA cutoff (somewhere between 0.5 and 1.0 MeV.) In spite of this, DRs are instructed to 

add missed neutron dose only for workers in the cylinder yards. There will have been pervasive, 

low-level neutron fields in other areas of the plant due to the alpha-N reaction, spontaneous 

fission, the presence of trace levels of transuranics in some feed stocks, and possible incidents or 

“slow cooker” events. Given these facts, SC&A recommends that all areas of the plant be 

evaluated to determine an appropriate missed dose component for neutron exposure. NIOSH 

should evaluate the advisability of using the PGDP recommended 200 mrem/2,000 hr as the 

basis for a more claimant favorable dose estimate for K-25 workers. 

Finding 8: Until 1980, some dosimeters were only processed upon request, resulting in 

ambiguity regarding the construction of doses in the early years. Until 1980, the TBD 

(Miles 2006) states that dosimeters were only processed upon request. Another TBD statement 

points out that ORNL provided K-25 dosimeter and processing technical support starting in 

1945. It is unclear from these two statements whether dosimeters were routinely processed for 

workers or only done in some random frequency. If the latter is true, many workers may have 

missed dose due to lack of processing or recording. SC&A recommends that this issue be 

investigated and appropriate data be collected to address this missed dose if NIOSH finds that it 

did occur. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

14 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

The Occupational External Dose TBD (Miles 2006, pg. 10) states that “From 1945 to 1979, 

ORNL processed dosimeters only on request,” yet there is no discussion as to the meaning of this 

statement. For example, who was able to make such a request, and on what basis? Were any 

random dosimeters selected to check for unanticipated exposures? What was entered in the 

record if a dosimeter was processed that revealed a worker had been receiving an exposure over 

an extended period? SC&A recommends that this issue be investigated and data collected in 

situations such as the percentage of issued badges that were processed, the procedures for 

selecting which badges to process, the procedures for handling positive results, and the 

implementation of a QA program if any, etc. 

Finding 9: Chronic neutron exposure opportunities may have been overlooked for the 

early years. For health physics and safety coverage during the early years, it seems that little 

attention was paid to the possibility of neutron exposures. While it is possible that this was 

because there were no significant neutron fields, it is also possible that limited staff, 

inexperience, inadequate instrumentation, and a generally more relaxed attitude to chronic 

exposure levels may have resulted in safety staff overlooking or ignoring neutron exposure 

potential. SC&A suggests that this issue should be revisited and a determination made as to 

whether some categories of workers could have been exposed to chronic low-level neutron 

fields. 

Finding 10: Potential exposures to Tc-99 betas were not recorded by dosimeters and are 

not addressed elsewhere in the TBD. It is also likely that the film badges used in the 1945 to 

1979 period did not detect Tc-99. (Details on wrapping and cover materials in mg/cm2

 would be 

helpful.) It is asserted that only skin contamination could have given rise to significant beta 

exposure due to Tc-99, yet this claim is unsupported by any discussion of typical quantities of 

Tc-99 that might be present or any measurements or calculations of dose rates. The potential for 

exposure to beta fields needs to be more fully evaluated, with a parallel consideration of the 

dosimetry in use at the time and the potential for unreported or under-reported dose. 

Finding 11: Reliance on a single neutron-to-photon ratio for the entire plant is 

questionable. Reliance on a single neutron-to-photon ratio for the entire plant geography and 

history and a ratio that additionally is based on a measurement at another facility is questionable. 

The K-25 plant had a number of potential sources of neutron exposure that will have varied over 

time as processes, facilities, procedures, impurities, and enrichments changed. Additional 

research and analysis is recommended to evaluate the neutron-to-photon ratio(s) that should be 

used to estimate missed neutron doses over the K-25 plant history. SC&A recommends that 

careful consideration be given to situations where the photon component of the field may have 

been effectively shielded by process equipment and pipe work, leaving a neutron component of 

exposure that is not accompanied by a significant photon component. This would undermine the 

application of the ratio method for these situations. 

Finding 12: All beta dosimetry was based on a uranium slab calibration. Given that it is 

likely that at least some workers were routinely exposed to Tc-99, and given that the dosimeters 

will have partly or completely missed this lower energy beta, SC&A recommends that an 

evaluation be performed to determine the degree to which Tc-99 dose was under-reported or 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

15 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

missed entirely. The use of only a uranium slab calibration may well have missed these lower 

energy betas. 

1.2.2 Secondary Findings 

Finding 13: There is a lack of guidance on bioassay interpretation. There is a lack of 

guidance on bioassay interpretation regarding appropriate assumptions for intake assessments. 

The TBD needs to either provide more specific guidance to the dose reconstructor on several 

parameters that must be chosen or adjusted for intake and dose assessment, or reference the 

documents that will provide this guidance. 

Finding 14: There is no comparison between measured and predicted ambient radiation 

dose data. The PGDP Occupational Environmental TBD, ORAUT-TKBS-0019-4 (East 2004) 

states that since 1962, “At PGDP all personnel wore film badges...” The ORNL Occupational 

Environmental TBD, ORAUT-TKBS-0012-4 (Burns 2004) states, “ORNL went to a take home 

badge (i.e., security badge and dosimeter combined) in the early 1950s...” It is reasonable to 

postulate that given similar activities to a sister site (PGDP) and being a part of the Oak Ridge 

Reservation (ORR), K-25 employed a similar personnel dosimetry arrangement for workers. A 

comparison between personnel dosimetry data (measured) with estimates based on ambient 

environmental exposures (predicted) would prove useful to validate the methods for 

reconstructing external environmental doses. 

Finding 15: The TBD does not provide a consistent time period for the processing of RU at 

K-25. The potential radionuclide contaminants in RU (Tc-99, Np-237, Pu-238, Pu-239, Pu-240, 

Pu-241, Pu-242, Am-241, Cm-242, and Cm-244) can give a significant increase in the dose from 

intakes of RU process material compared to natural uranium ore sources that do not contain these 

radionuclide contaminants. The Occupational Internal Dose TBD (Thomas 2006) does identify a 

default isotopic distribution that contains some of these contaminants to assume for intakes in 

Table 5-6; however, it does not make it clear for which years to assume this default. The TBD 

should identify specific time periods that RU and its default isotopic distribution are to be 

assumed in intake assessment for possible claimant-favorable exposures. 

Finding 16: The TBD fails to adequately define frequency and assess all types of x-rays in 

occupational medical exposure. Initial guidance on medical exposure and dose guidelines, as 

presented in Revision 2 of ORAUT-OTIB-0006 (Kathren 2003), provides basic guidelines that 

the dose reconstructor can use to ensure that all occupational medical exposures are reasonably 

included in determining the overall dose estimations for claimants. Unfortunately, the 

interpretation, to date, by the contractor (ORAU) has not been applied conservatively to be 

claimant favorable. The Occupational Medical Dose TBD (Turner 2006) assumes an 

interpretation that has been considered and applied at other sites, such as the Mound Plant, Los 

Alamos National Laboratory (LANL), Paducah, and Pinellas. It is assumed that occupationally 

related medical exposures are included in dose reconstruction for pre-employment, annual, 

health monitoring examinations, and post-employment chest x-rays. Although NIOSH has stated 

that they rely on the K-25 Site to provide all medical records information (Attachment 4), an 

interview with a K-25 medical x-ray technologist, there since 1957 (Attachment 2, Medical 

X-ray Procedures section), indicated that the data provided may not contain information retired 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

16 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

to microfiche. In the early period, workers with potential for exposure to uranium dust 

inhalation were reported in the TBD (Turner 2006, Table 3-1) to have often received monthly 

chest x-rays. NIOSH needs to review the microfiche to verify the frequency of chest x-rays in 

the early years, and what the appropriate number of chest x-rays for inclusion in dose 

reconstruction is, for workers exposed to uranium dust. This would need to be developed for 

those workers whose individual medical records do not document the frequency of chest x-rays. 

Finding 17: Techniques and protocols increase uncertainty of dose conversion factors 

(DCFs) listed in the TBD. The Occupational Medical Dose TBD (Turner 2006) provides little 

documentation to support the assumed techniques and protocols applied to calculate the dose, 

which is mainly derived from ICRP Publication 34 (ICRP 1982). The TBD states that a 

posterior-anterior (PA) chest x-ray was typically the only view taken until the early 1950s. It is 

an undocumented assumption in the TBD that exams required only a PA view. SC&A has 

inquired whether a definitive protocol existed to validate that chest exams possibly included PA 

views and lateral (LAT) views on a limited basis. NIOSH has acknowledged in other TBD 

reviews that the lack of verifiable protocols is a generic problem at many sites, has planned to 

search all available records, and will include pertinent records and references in any future 

revision of this section of the TBD. The Occupational Medical Dose TBD is also deficient in 

that little documentation exists to validate x-ray protocols, equipment maintenance, and upkeep 

records. 

1.3 OPPORTUNITIES FOR IMPROVEMENT 

(1) There is ambiguity in the Internal Dosimetry TBD (Thomas 2006) about ending of RU 

processing. 

The Site Description TBD (Szalinski 2006b) states in one section that RU was processed 

through 1977, and through 1984 in another section; however, the Internal Dose TBD 

identifies that 1976 was the last year of using RU for feed material. These TBDs need to 

be in agreement. The lack of considering that RU was also used in later periods could 

lead to an incorrect intake assessment and unfavorable determination for the claimant. 

NIOSH, in its response to SC&A’s Internal Dose section question 9, which is included in 

Attachment 3 of this report, states that the reference that they used to identify the period 

that RU was received at K-25 states that it was 1952 through 1988 (BJC 2000), and that 

they will revise the appropriate section of the TBD for clarity. In the conference call 

(Attachment 4, Internal Dosimetry, question 9), NIOSH stated that all intakes of uranium 

will assume that RU was involved from 1952 through the present, and will use the default 

isotopic distribution in the Internal Dose TBD (Table 5-6) for assessed intakes. 

(2) Use of ICRP 23 (ICRP 1974) Reference Man anatomical and physiological data may be 

questionable, because this document has been updated with ICRP 89 data (ICRP 2002). 

A determination should be made on the applicability of using the larger daily urine 

excretion volume from ICRP 89 for the conversion of urine bioassay concentration data 

(μg U/liter) to 24-hour excretion activity that is used to calculate intakes. The ICRP 89 

volume (1.6 liters for men and 1.2 liters for women) is larger than the volume 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

17 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

recommended in ICRP 23 (1.4 liters for men and 1.0 liters for women). Using the larger 

volumes will increase the intakes and doses determined from concentration (e.g., mass or 

activity per liter) bioassay data interpretation for internal dose assessment. If NIOSH 

does not believe that the larger volumes are applicable, it should state this and defend the 

use of the smaller volumes. 

(3) There is no discussion on the respiratory protection program—air sampling or other 

radiological control practices—that would help provide potentially valuable information 

for internal dose reconstruction. 

This information provides a general overview and possibly specific data on the conditions 

that claimants were exposed to and the methods employed to minimize or limit intakes of 

radionuclides. This information may be useful if a dose reconstructor must make a 

professional judgment decision on the potential for intakes to occur. Another important 

piece of information that may be extracted from this is the level of knowledge of a 

claimant’s work locations, which would help identify their specific exposure conditions. 

There also is no discussion of the cascade improvement/cascade upgrade programs in the 

1970s, which may have involved increased exposure problems (mentioned in the site 

expert’s interview in Attachment 2). 

In addition to this basic program information, NIOSH needs to determine if the site has 

done any airborne radionuclide particle size and/or lung solubility analyses for the 

radionuclides in the source terms of buildings, and then provide any applicable 

information to dose reconstructors. 

NIOSH, in its response to SC&A’s Internal Dose section question 5 (Attachment 3), 

states that the primary method of evaluation for dose reconstructions is use of individual 

monitoring data, and, if it is necessary, area-monitoring information will be reviewed. In 

its response to question 3 of this attachment, NIOSH states that particle size distributions 

are specific to operations and conditions in the locations, and it is not reasonable to 

assume that a measurement in one location is universally applicable to other locations. 

However, it notes that dose reconstructors may use site-specific information if it is 

contrary to the 5-micrometer default activity median aerodynamic diameter (AMAD) 

assumption. 

(4) Table 5-7 (Thomas 2006) identifies in-vitro MDCs, yet incorrectly labels these as being 

in mg/L units in its heading, and no fecal bioassay MDCs are identified. 

The units do not need to be identified in the heading of Table 5-7 of the Internal Dose 

TBD, because each bioassay MDC unit is identified in the table next to its numerical 

value (some in mass and some in activity concentration units). The type of samples these 

MDCs apply to is not identified specifically in the table, but from reading the text, it can 

be assumed that these are for urine bioassay, because it is the only in-vitro bioassay 

discussed. No fecal bioassay is identified, which infers that fecal bioassay data is not 

available. During the site interview and document search, a research paper was obtained 

that indicated fecal sampling was performed for a period from 1964–1966 at the Uranium 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

18 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Recovery Facility (Schultz 1966), and this was reported to NIOSH in the conference call 

(Attachment 4, Internal Dosimetry, question 2). NIOSH should discuss the availability of 

any fecal bioassay data. 

(5) A discussion of the determination for potential radium and thorium sources is needed to 

identify if dose assessment for workplace-related radon exposures is warranted. 

Although K-25 was primarily a uranium-processing site, it was claimed in a project 

meeting (NIOSH 2005) that there were some special research missions at the site. 

NIOSH should look for any information that could indicate the significant use of radium 

or thorium sources. If any sources are found, NIOSH should then discuss the internal 

dosimetry effort (including radon dose assessment) that may be needed to account for 

these. NIOSH, in its response to SC&A’s Internal Dose section question 8 

(Attachment 3), states that, “No information on the presence of radium sources at the site 

is currently available.” The site expert interviews indicated that radium was a significant 

radionuclide in K-1024, K-1030, and K-1035 (Attachment 2); therefore, it is 

recommended that NIOSH investigate this possibility, and any potential radium and 

radon doses that could have resulted. 

(6) Occupational Medical Dose TBD (Turner 2006) provides little documentation to support 

the assumed techniques and protocols applied to calculate the dose, which is mainly 

derived from ICRP Publication 34 (ICRP 1982). 

The TBD provides a summary on the use of PA and LAT chest x-rays. NIOSH should 

attempt to find additional data to validate that the process described leads to the most 

claimant-favorable dose for occupationally related chest x-rays. 

(7) Figure 4-1 of the Occupational Environmental Dose TBD (East 2006) shows major 

buildings and environmental monitoring stations relative to release points. 

It would be valuable to include wind rose data to validate the chosen monitoring stations. 

Also include the discussed administrative area in relation to these locations. Table 4D-4 

provides estimated average gamma radiation levels for two perimeter K-25 stations. For 

the years 1973–1985, asterisks need to be included denoting data derived from empirical 

site measurements. 

(8) Photographs showing typical facilities, equipment, and processes would be helpful. 

Photographs showing typical facilities, equipment, and processes would assist dose 

reconstructors and reviewers unfamiliar with the K-25 facilities in understanding the 

layout, inherent shielding, and distances commonly encountered by workers. Any photos 

of the dosimeters in use and associated dosimeter processing facilities and equipment 

would also be helpful. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

19 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

(9) A discussion of major incidents is needed. 

A discussion of major incidents throughout the site history and how unusual doses were 

added to the record over the extended time period under review would be helpful. 

(10) A discussion of the range and type of non-standard operations would be helpful. 

A discussion of the range and type of non-standard operations, such as plant upgrades, 

maintenance, research and development (R&D), etc., would be helpful. For example, 

while Tc-99 recovery is mentioned, it is unclear to the reader what this entails. 

(11) The Site Description TBD needs a comprehensive list of buildings. 

Site interviews with a number of workers make it clear that a number of buildings are not 

addressed in the site profile. K-25 Site Expert Interviewees (Attachment 2, 

Production/Operations section) identified numerous buildings including K-101, K-131, 

K-631, and others. SC&A recommends that NIOSH prepare a comprehensive list of all 

the buildings on the site and use this to identify work areas with potential for missed 

dose. The table in Attachment 2 should be helpful to the dose reconstructor when 

reviewing a claimant’s work area for potential higher external or internal dose. This is 

important, as there could be an opportunity for exposure to internal and external hazards, 

even if the building is clean. There is documentation of contaminated equipment being 

transferred to inactive areas for repairs or modification during the life of the K-25 plant. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

20 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

2.0 SCOPE AND INTRODUCTION 

The review of the K-25 Site Profile was conducted from October 3, 2006– February 22, 2007, by 

a team of SC&A health physicists and technical personnel. 

2.1 REVIEW SCOPE 

Under the EEOICPA and Federal regulations defined in Title 42, Part 82, Methods for Radiation 

Dose Reconstruction Under the Energy Employees Occupational Illness Compensation 

Program, of the Code of Federal Regulations (42 CFR Part 82), the Advisory Board is mandated 

to conduct an independent review of the methods and procedures used by NIOSH and its 

contractors for dose reconstruction. As a contractor to the Advisory Board, SC&A has been 

charged under Task 1 to support the Advisory Board in this effort by independently evaluating a 

select number of site profiles that correspond to specific facilities at which energy employees 

worked and were exposed to ionizing radiation. 

This report provides a review of the following six documents related to historical occupational 

exposures at the K-25 Gaseous Diffusion Plant: 

•	 ORAUT-TKBS-0009-1, K-25 Introduction, Rev. 01, May 4, 2006 (Szalinski 2006a). 

•	 ORAUT-TKBS-0009-2, Technical Basis Document for the K-25 Site – Site Description, 

Rev. 01, October 4, 2006 (Szalinski 2006b). 

•	 ORAUT-TKBS-0009-3, Technical Basis Document for K-25 the Site – Occupational 

Medical Dose, Rev. 00 PC-1, November 7, 2006 (Turner 2006). 

•	 ORAUT-TKBS-0009-4, Technical Basis Document for the K-25 Site – Occupational 

Environmental Dose, Rev. 00 PC-1, September 26, 2006 (East 2006). 

•	 ORAUT-TKBS-0009-5, K-25 Gaseous Diffusion Plant -Occupational Internal Dose Rev. 

00 PC-1, October 4, 2006 (Thomas 2006). 

•	 ORAUT-TKBS-0009-6, Technical Basis Document for the K-25 Site – Occupational 

Internal Dose, Rev. 00 PC-1, September 26, 2006 Miles 2006). 

These documents are supplemented by technical information bulletins (TIBs), which provide 

additional guidance to the dose reconstructor. A complete list of these documents is available in 

Attachment 1. 

Implementation guidance is also provided in “workbooks,” which have been developed by 

NIOSH for selected sites to provide more definitive direction to the dose reconstructors on how 

to interpret and apply TBDs, as well as other available information. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

21 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

SC&A, in support of the Advisory Board, has critically evaluated the K-25 Site TBDs for the 

following: 

•	 Determine the completeness of the information gathered by NIOSH in behalf of the site 

profile, with a view to assessing its adequacy and accuracy in supporting individual dose 

reconstructions 

•	 Assess the technical merit of the data/information 

•	 Assess NIOSH’s use of the data in dose reconstructions 

SC&A’s review of the six TBDs focuses on the quality and completeness of the data that 

characterized the facility and its operations, and the use of these data in dose reconstruction. The 

review was conducted in accordance with SC&A Standard Operating Procedure for Performing 

Site Profile Reviews (SC&A 2004), which was approved by the Advisory Board. 

The review is directed at “sampling” the site profile analyses and data for validation purposes. 

The review does not provide a rigorous quality control process, whereby actual analyses and 

calculations are duplicated or verified. The scope and depth of the review are focused on aspects 

or parameters of the site profile that would be particularly influential in deriving dose 

reconstructions, bridging uncertainties, or correcting technical inaccuracies. This review does 

not explicitly address the issue of radiation exposures to cleanup workers and decommissioning 

workers, as that is not addressed in the TBDs. 

The six TBDs serve as site-specific guidance documents used in support of dose reconstructions. 

These site profiles provide the health physicists who conduct dose reconstructions on behalf of 

NIOSH with consistent general information and specifications to support their individual dose 

reconstructions. This report was prepared by SC&A to provide the Advisory Board with an 

evaluation of whether and how the TBDs can support dose reconstruction decisions. The criteria 

for evaluation include whether the TBDs provide a basis for scientifically supportable dose 

reconstruction in a manner that is adequate, complete, efficient, and claimant favorable. 

Specifically, these criteria were viewed from the lens of whether dose reconstructions based on 

the TBDs would provide for robust compensation decisions. 

The basic principle of dose reconstruction is to characterize the radiation environments to which 

workers were exposed, and determine the level of exposure the worker received in that 

environment through time. The hierarchy of data used for developing dose reconstruction 

methodologies is dosimeter readings and bioassay data, coworker data and workplace monitoring 

data, and process description information or source term data. 

2.2 REVIEW APPROACH 

SC&A’s review of the TBDs and supporting documentation concentrated on determining the 

completeness of data collected by NIOSH, the adequacy of existing K-25 personnel and 

environmental monitoring data, and the evaluation of key dose reconstruction assumptions. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

22 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

2.3 REPORT ORGANIZATION 

In accordance with directions provided by the Advisory Board, and with site profile review 

procedures prepared by SC&A and approved by the Advisory Board, this report is organized into 

the following sections: 

(1) Executive Summary 

(2) Scope and Introduction 

(3) Assessment Criteria and Method 

(4) Site Profile Strengths 

(5) Vertical Issues 

(6) Overall Adequacy of the Site Profile as a Basis for Dose Reconstruction 

Based on the issues raised in each of these sections, SC&A prepared a list of findings, which are 

provided in the Executive Summary. Issues are designated as Findings if SC&A believes that 

they represent deficiencies in the TBD that need to be corrected, and which have the potential to 

have a substantial impact on at least some dose reconstructions. Issues can also be designated as 

Secondary Issues if they simply raise questions, which, if addressed, would further improve the 

TBDs and may possibly reveal deficiencies that will need to be addressed in future revisions of 

the TBDs. 

Many of the issues that surfaced in the report correspond to more than one of the major 

objectives (i.e., strengths, completeness of data, technical accuracy, consistency among site 

profiles, and regulatory compliance). Section 6.0 provides a list of the issues in summary form, 

and to which objective the particular issue applies. 

The TBDs, in many ways, have done a successful job in addressing a series of technical 

challenges. In other areas, the TBDs exhibit shortcomings that may influence some dose 

reconstructions in a substantial manner. Major issue areas include the following: 

•	 Insufficient data for early worker dose reconstructions 

•	 Appropriate uranium enrichment assumptions for internal dose assessment are not 

sufficiently documented 

•	 Lack of guidance for default absorption classes to assume for internal dose assessment 

•	 Inadequate consideration of missed dose to other radionuclides not as well characterized 

or monitored 

•	 Lack of incident information for accurate and claimant-favorable internal dose 

reconstructions 

•	 Underestimation of neutron dose, due to the assumption that the only major source of 

neutron exposure was around the cylinder yards 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

23 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

•	 Lack of data, particularly in the early days, of the type of x-ray equipment used, the beam 

quality, and the x-ray protocols that impact the dose conversion factors (DCFs) 

SC&A believes that these important issues need to be effectively dealt with in any upcoming 

revisions to the K-25 Site Profile TBDs in order that more claimant-favorable dose 

reconstructions can be effectively conducted in areas where these data gaps exist. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

24 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

3.0 ASSESSMENT CRITERIA AND METHODS 

SC&A is charged with evaluating the approach set forth in the site profiles that is used in the 

individual dose reconstruction process. These documents are reviewed for their completeness, 

technical accuracy, adequacy of data, consistency with other site profiles, and compliance with 

the stated objectives, as defined in SC&A Standard Operating Procedure for Performing Site 

Profile Reviews (SC&A 2004). This review is specific to the K-25 Site Profile, supporting TIBs, 

and dose reconstruction worksheets; however, items identified in this report may be applied to 

other facilities, especially facilities with similar source terms and exposure conditions. The 

review identifies a number of issues and discusses the degree to which the site profile fulfills the 

review objectives delineated in SC&A’s site profile review procedure. 

3.1 OBJECTIVES 

SC&A reviewed the site profile with respect to the degree to which technically sound judgments 

or assumptions are employed. In addition, the review identifies assumptions by NIOSH that give 

the benefit of the doubt to the claimant. 

3.1.1 Objective 1: Completeness of Data Sources 

SC&A reviewed the site profile with respect to Objective 1, which requires SC&A to identify 

principal sources of data and information that are applicable to the development of the site 

profile. The two elements examined under this objective include (1) determining if the site 

profile made use of available data considered relevant and significant to the dose reconstruction, 

and (2) investigating whether other relevant/significant sources are available, but were not used 

in the development of the site profile. For example, if data are available in site technical reports 

or other available site documents for particular processes, and if the TBDs have not taken into 

consideration these data where it should have, this would constitute a completeness of data issue. 

The Oak Ridge Associated Universities (ORAU) site profile document database, including the 

referenced sources in the TBDs, was evaluated to determine the relevance of the data collected 

by NIOSH to the development of the site profile. Additionally, SC&A evaluated records 

publicly available relating to the K-25 Site and records provided by site experts. 

3.1.2 Objective 2: Technical Accuracy 

SC&A reviewed the site profile with respect to Objective 2, which requires SC&A to perform a 

critical assessment of the methods used in the site profile to develop technically defensible 

guidance or instruction, including evaluating field characterization data, source term data, 

technical reports, standards and guidance documents, and literature related to processes that 

occurred at K-25. The goal of this objective is to first analyze the data according to sound 

scientific principles, and then to evaluate this information in the context of compensation. If, for 

example, SC&A found that the technical approach used by NIOSH was not scientifically sound 

or claimant favorable, this would constitute a technical accuracy issue. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

25 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

3.1.3 Objective 3: Adequacy of Data 

SC&A reviewed the site profile with respect to Objective 3, which requires SC&A to determine 

whether the data and guidance presented in the site profile are sufficiently detailed and complete 

to conduct dose reconstruction, and whether a defensible approach has been developed in the 

absence of data. In addition, this objective requires SC&A to assess the credibility of the data 

used for dose reconstruction. The adequacy of the data identifies gaps in the facility data that 

may influence the outcome of the dose reconstruction process. For example, if a site did not 

monitor all workers exposed to neutrons who should have been monitored, this would be 

considered a gap and, thus, an inadequacy in the data. 

3.1.4 Objective 4: Consistency among Site Profiles 

SC&A reviewed the site profile with respect to Objective 4, which requires SC&A to identify 

common elements within site profiles completed or reviewed to date, as appropriate. In order to 

accomplish this objective, the K-25 TBD was compared to several of the sites already reviewed 

by SC&A. 

3.1.5 Objective 5: Regulatory Compliance 

SC&A reviewed the site profile with respect to Objective 5, which requires SC&A to evaluate 

the degree to which the site profile complies with stated policy and directives contained in 

42 CFR Part 82. In addition, SC&A evaluated the TBD for adherence to general quality 

assurance policies and procedures utilized for the performance of dose reconstructions. 

In order to place the above objectives into the proper context as they pertain to the site profile, it 

is important to briefly review key elements of the dose reconstruction process, as specified in 

42 CFR Part 82. Federal regulations specify that a dose reconstruction can be broadly placed 

into one of three discrete categories. These three categories differ greatly in terms of their 

dependence on and the completeness of available dose data, as well as on the 

accuracy/uncertainty of data. 

Category 1: Least challenged by any deficiencies in available dose/monitoring data are dose 

reconstructions for which even a partial assessment (or minimized dose(s)) corresponds to a 

probability of causation (POC) value in excess of 50%, and assures compensability to the 

claimant. Such partial/incomplete dose reconstructions with a POC greater than 50% may, in 

some cases, involve only a limited amount of external or internal data. In extreme cases, even a 

total absence of a positive measurement may suffice for an assigned organ dose that results in a 

POC greater than 50%. For this reason, dose reconstructions in behalf of this category may only 

be marginally affected by incomplete/missing data or uncertainty of the measurements. In fact, 

regulatory guidelines recommend the use of a partial/incomplete dose reconstruction, the 

minimization of dose, and the exclusion of uncertainty for reasons of process efficiency, as long 

as this limited effort produces a POC of greater than or equal to 50%. 

Category 2: A second category of dose reconstruction is defined by Federal guidance, which 

recommends the use of “worst-case” assumptions. The purpose of worst-case assumptions in 

dose reconstruction is to derive maximal or highly improbable dose assignments. For example, a 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

26 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

worst-case assumption may place a worker at a given work location 24 hours per day and 

365 days per year. The use of such maximized (or upper-bound) values, however, is limited to 

those instances where the resultant maximized doses yield POC values below 50%, which are 

not compensated. For this second category, the dose reconstructor needs only to ensure that all 

potential internal and external exposure pathways have been considered. 

The obvious benefit of worst-case assumptions and the use of maximized doses in dose 

reconstruction is efficiency. Efficiency is achieved by the fact that maximized doses avoid the 

need for precise data and eliminates consideration for the uncertainty of the dose. Lastly, the use 

of bounding values in dose reconstruction minimizes any controversy regarding the decision not 

to compensate a claim. 

Although simplistic in design, to satisfy this type of a dose reconstruction, the TBD must, at a 

minimum, provide information and data that clearly identify (1) all potential radionuclides, 

(2) all potential modes of exposure, and (3) upper limits for each contaminant and mode of 

exposure. Thus, for external exposures, maximum dose rates must be identified in time and 

space that correspond to a worker’s employment period, work locations, and job assignment. 

Similarly, in order to maximize internal exposures, highest air concentrations and surface 

contaminations must be identified. 

Category 3: The most complex and challenging dose reconstructions consist of claims where 

the case cannot be dealt with under one of the two categories above. For instance, when a 

minimum dose estimate does not result in compensation, a next step is required to make a more 

complete estimate. Or when a worst-case dose estimate that has assumptions that may be 

physically implausible results in a POC greater than 50%, a more refined analysis is required. A 

more refined estimate may be required either to deny or to compensate. In such dose 

reconstructions, which may be represented as “reasonable,” NIOSH has committed to resolve 

uncertainties in favor of the claimant. According to 42 CFR Part 82, NIOSH interprets 

“reasonable estimates” of radiation dose to mean the following: 

. . . estimates calculated using a substantial basis of fact and the application of 

science-based, logical assumptions to supplement or interpret the factual basis. 

Claimants will in no case be harmed by any level of uncertainty involved in 

their claims, since assumptions applied by NIOSH will consistently give the 

benefit of the doubt to claimants. [Emphasis added.] 

In order to achieve the five objectives described above, SC&A reviewed each of the six TBDs, 

their supplemental attachments, and TIBs, giving due consideration to the three categories of 

dose reconstructions that the site profile is intended to support. The six K-25 TBDs provide 

well-organized and user-friendly information for the dose reconstructor when adequate data were 

available to do that comprehensively. 

ORAUT-TKBS-0009-1, Rev. 00, Technical Basis Document for K-25 Site – Introduction 

(Szalinski 2006a), explains the purpose and the scope of the site profile. SC&A was attentive to 

this section, because it explains the role of each TBD in support of the dose reconstruction 

process. During the course of its review, SC&A was cognizant of the fact that the site profile is 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

27 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

not required by the EEOICPA or by 42 CFR Part 82, which implements the statute. Site profiles 

were developed by NIOSH as a resource to the dose reconstructors for identifying site-specific 

practices, parameter values, and factors that are relevant to dose reconstruction. Based on 

information provided by NIOSH personnel, SC&A understands that site profiles are living 

documents, which are revised, refined, and supplemented with TIBs as required to help dose 

reconstructors. Site profiles are not intended to be prescriptive nor necessarily complete in terms 

of addressing every possible issue that may be relevant to a given dose reconstruction. Hence, 

the introduction helps in framing the scope of the site profile. As will be discussed later in this 

report, NIOSH may want to include additional qualifying information in the introduction to this 

and other site profiles describing the dose reconstruction issues that are not explicitly addressed 

by a given site profile. 

ORAUT-TKBS-0009-2, Rev. 01, Technical Basis Document for the K-25 Site – Site Description 

(Szalinski 2006b), is an extremely important document because it provides a description of the 

facilities, processes, and historical information that serve as the underpinning for subsequent 

K-25 TBDs. 

ORAUT-TKBS-0009-3, Rev. 00 PC-1, Technical Basis Document for the K-25 Site – 

Occupational Medical Dose (Turner 2006), provides an overview of the sources, types of 

exposure, and the frequency of exams that workers potentially received. 

ORAUT-TKBS-0009-4, Rev. 00 PC-1, Technical Basis Document for the K-25 Site – 

Occupational Environmental Dose (East 2006), provides background information and guidance 

to dose reconstructors for reconstructing the doses to unmonitored workers outside of the 

facilities at the site who may have been exposed to routine and episodic airborne emissions from 

these facilities. 

ORAUT-TKBS-0009-5, Rev. 00 PC-1, K-25 Gaseous Diffusion Plant – Occupational Internal 

Dose (Thomas 2006), presents background information and guidance to dose reconstructors for 

deriving occupational internal doses to workers. 

ORAUT-TKBS-0012-6, Rev. 00, Technical Basis Document for the K-25 Site – Occupational 

External Dose (Miles 2006), presents background information and guidance to dose 

reconstructors for deriving occupational external doses to workers. 

In accordance with SC&A’s site profile review procedures, SC&A performed an initial review of 

the six TBDs, their supporting documentation, and the TIBs or procedures (PROCs). Interviews 

with Site Experts are provided in Attachment 2. SC&A then submitted questions to NIOSH with 

regard to assumptions and methodologies used in the site profile. Prior to the conference calls 

with SC&A for the K-25 Site Introduction TBD (Szalinski 2006a), the K-25 Site Description 

TBD (Szalinski 2006b), the K-25 Site Occupational Medical Dose TBD (Turner 2006), the K-25 

Occupational Environmental Dose TBD (East 2006), the K-25 Occupational Internal Dose TBD 

(Thomas 2006), and the K-25 Site Occupational External Dose TBD (Miles 2006), NIOSH 

provided written responses to SC&A Questions (Attachment 3). The SC&A key questions and 

the NIOSH responses to the SC&A are provided in Attachment 3. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

28 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Two conference calls were then conducted with NIOSH, ORAU, and the SC&A team to allow 

NIOSH to provide clarifications and to explain the approaches employed in the site profile 

TBDs. A summary of the conference calls with NIOSH, ORAU, and SC&A is provided in 

Attachment 4. 

Information provided in the conference calls with NIOSH was evaluated against the preliminary 

findings to finalize the vertical issues1

 addressed in the audit report. There are two levels of 

review for this report. First, SC&A team members review the report internally. The second 

level, referred to as the expanded review cycle, will consist of a review of this draft by the 

Advisory Board and NIOSH. 

After the Advisory Board and NIOSH have an opportunity to review this draft, SC&A plans to 

request a meeting with Advisory Board members and NIOSH representatives to discuss the 

report. Following this meeting, we will revise this report and deliver the final version to the 

Advisory Board and to NIOSH. We anticipate that, in accordance with the procedures followed 

during previous site profile reviews, the report will then be published on the NIOSH Web site 

and discussed at the next Advisory Board meeting. This last step in the review cycle completes 

SC&A’s role in the review process, unless the Advisory Board requests SC&A to participate in 

additional discussions regarding the closeout of issues, or if NIOSH issues revisions to the TBDs 

or additional TIBs, and the Advisory Board requests SC&A to review these documents. 

Finally, it is important to note that SC&A’s review of the six TBDs and their supporting TIBs is 

not exhaustive. These are large, complex documents, and SC&A used its judgment in selecting 

those issues that we believe are important with respect to dose reconstruction. 

1

 The term “vertical issues” refers to specific issues identified during our review, which were identified as 

requiring more in-depth analysis, due to their potential to have a significant impact on dose reconstruction. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

29 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

4.0 SITE PROFILE STRENGTHS 

In developing a TBD, the assumptions used must be fair, consistent, and scientifically robust, 

and uncertainties and inadequacies in source data must be explicitly addressed. The 

development of the TBD must also consider efficiency in the process of analyzing individual 

exposure histories, so that claims can be processed in a timely manner. With this perspective in 

mind, we identified a number of strengths in the K-25 Site Profile TBDs. These strengths are 

described in the following sections. 

4.1 INTERNAL DOSE TBD STRENGTHS 

In the Occupational Internal Dose TBD (Thomas 2006), Table 5-5 identifies, in detail, the 

isotopes of plutonium and their activity per unit mass in the facility-specific radionuclide 

conversion factors. This TBD also identifies the urine bioassay minimum detectable 

concentrations (MDCs) applicable for the different in-vitro bioassays in Table 5-7 and the 

in-vivo minimum detectable activities (MDAs) in Table 5-9 for the site history, which are also 

helpful for internal dose assessment. 

The K-25 Occupational Internal Dose TBD (Thomas 2006) had sections that were relatively 

consistent with other site profiles. Source term information for locations and bioassay analytical 

detection levels were covered similarly to the Paducah Gaseous Diffusion Plant Internal Dose 

TBD (Mantooth 2006) and the Portsmouth Gaseous Diffusion Plant Internal Dose TBD 

(Demopoulos 2004). The K-25 Internal Dosimetry Coworker Data TBD (Cherry 2006) uses 

similar approaches for estimating intakes and doses for non-monitored claimants as found in the 

Paducah Internal Dosimetry Coworker Data TBD (Ikenberry 2005). 

Where in-vivo and in-vitro analyses are available, this information is provided for use in the 

determination of internal dose. 

4.2 EXTERNAL DOSE TBD STRENGTHS 

A good breakdown of the various site locations and activities as a function of time was provided. 

Dosimetry methods used for beta, photon, and neutron dose monitoring were described 

separately, and also as a function of time and technology changes. Bioassay methods and their 

associated detection limits used over the site history were provided (Thomas 2006). Ratios of 

U:TRU and U:Tc radionuclides were described in good detail in the Site Description TBD 

(Szalinski 2006b). Some prescribed health physics monitoring procedures and recordkeeping 

methods were described, along with the logbooks containing this information. K-25 has been 

fortunate to have noted scientists and R&D facilities to address radiation and health physics 

problems throughout its years of operations. 

A well-developed approach is in place to address potentially overlooked chronic low-level skin 

contamination exposures (Miles 2006, Section 6.7.2). 

Where routine beta/gamma and neutron dosimeters are available and adequate, this information 

is provided for use in determination of external exposure. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

30 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

4.3 MEDICAL DOSE STRENGTHS 

Within the Occupational Medical Dose TBD (Turner 2006), a very helpful table has been 

developed (Table 3.3, pg. 8) that assists the dose reconstructor in finding the appropriate organ 

dose per x-ray for the various x-ray examinations from 1944–2000. 

Likewise, the Occupational Medical Dose TBD additionally provides Table 3.2 on page 7 that 

summarized information taken from Cardarelli et al. 2002. This table nicely summarizes each 

x-ray machine kVp kV) output, the assumed half-value level (HVL) of Al, the image size, and 

the entrance skin exposure (ESE) for both PA and LAT films. A medical x-ray technologist 

interviewed during the K-25 site visit did, however, describe an x-ray machine currently in use 

that is not included in the Occupational Medical TBD. From 1987 to the present, the K-25 Site 

Medical Department has been using a Bennett D-5251 Unit with a Eureka Tube (Inovision 

Model 4000) with an automatic collimator. 

4.4 ENVIRONMENTAL DOSE TBD STRENGTHS 

The TBDs’ use of personnel monitoring data and environmental monitoring data to determine 

dose is consistent with the requirements outlined in 42 CFR Part 82, which state, “Where 

environmental measurements are available, these data are used as the basis for environmental 

dose.” 

The K-25 Occupational Environmental Dose TBD (East 2006) has provided a good summary of 

the occupational environmental dose received by unmonitored workers from onsite releases to 

the environment and elevated ambient radiation. The contribution from soil resuspension is 

accounted for in excess conservatism used to account for limitations in the source term. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

31 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

5.0 VERTICAL ISSUES 

SC&A has developed a list of key issues regarding the K-25 Site Profile. These issues relate to 

each of the five objectives defined in SC&A’s review procedures (SC&A 2004). Some issues 

are related to a particular objective, while others cover several objectives. Many of the issues 

raised below are applicable to other DOE and Atomic Weapons Employer sites, and should be 

considered in the preparation and revision of other site profiles. 

5.1	 ISSUE 1: MORE GUIDANCE IS NEEDED ON APPROPRIATE ENRICHMENT 

WHEN INTERPRETING URANIUM BIOASSAY MASS CONCENTRATION 

DATA 

The K-25 Occupational Internal Dose TBD (Thomas 2006) needs to provide more guidance on 

appropriate enrichment to assume when interpreting uranium bioassay mass concentration data, 

and the enrichment assumed for the default isotopic distribution may not be appropriate or 

claimant favorable. 

Section 5.3, Scope, of the TBD (Thomas 2006) states the following: 

The facility processed both virgin feed material and recycled or reprocessed 

reactor fuel to enrichments of up to 93% (by weight) of 235U from 1945 to 1964. 

After 1964 the highest enrichment was 5%. 

Section 5.4, Source Term, of the TBD (Thomas 2006) states the following: 

The primary mission of K-25 was to enrich uranium in the form of UF6 (for use in 

domestic and foreign commercial power reactors) from roughly 0.7% 235U 

(natural enrichment) to 93.5% 235U (DOE 2000a). 

Table 5-1 provides isotopic fraction information on four uranium enrichments (2%, 4%, 93%, 

and natural) that were handled at K-25 along with the default (2%) to be used when information 

is inadequate to identify the potential enrichment to which the claimant may have been exposed. 

There is little discussion on which specific enrichment to use for intake and dose assessment in 

relation to the buildings or time frames in which the claimant may have worked. It is critical to 

choose a correct uranium enrichment when interpreting uranium bioassay mass concentration 

data (typically in μg/liter). When assessing intakes and internal doses using this data, the mass 

must be converted to activities of the isotopes that make up the mass to calculate radiation doses. 

Most of the bioassay data for K-25 is in urine mass concentration units, so the enrichment 

assumption will affect most internal dose assessments. As shown in Table 5-1, the activities of 

specific uranium isotopes change as enrichment increases. These changes result in the total 

alpha activity that gives the dose going up several fold with increasing enrichment (total of 

activities for natural = 0.0254 Bq/μg; 2% = 0.0389 Bq/μg; 4% = 0.0792 Bq/μg; 93% = 

2.489 Bq/μg). The majority of the increase in activity as enrichment increases is from the U-234 

isotope, which enriches at a higher rate through the diffusion process than the U-235 isotope, due 

to its smaller mass number. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

32 of 191 

 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

It is obvious from the K-25 Site Description (Szalinski 2006b) that the enrichments involved 

with intakes could have been much higher than the default assumption of 2%. This default 

enrichment also is in disagreement with statements and other information in this TBD. 

Footnote 2 in Section 5.3 on page 6, which refers to the first statement from the text quoted 

above, states “The predominant enrichment level was 3.0%...” (Szalinski 2006b). Also, in 

Table 5-4, Source term summary by location, 3% enrichment is identified in three locations; 

however, 2% is not identified in any locations in the table. Use of 3 % enrichment as the default 

enrichment would significantly increase the alpha activity and dose assessed in intakes from 

interpretation of urine bioassay mass concentration data. Therefore, it is recommended that 

NIOSH review the appropriateness of the default uranium enrichment assumption for accuracy 

and claimant-favorable assessments. 

NIOSH in its response to SC&A’s internal dose section question 16, which is included in 

Attachment 3 of this report, states that: 

...the predominant enrichment level at K-25 was 3%, except for the period of time 

when reprocessed fuel was used as feed. The dose reconstructors will select the 

input parameters on enrichment based upon the dates of exposure for each 

claimant.” (Attachment 3, question 16) 

In its response to question 17 of Attachment 3, NIOSH states the following: 

Because the predominant enrichment level at K-25 is described in Section 5.3 as 

being 3%, Table 5-1 will be revised to capture this level as the default.” 

(Attachment 3, question 17) 

NIOSH appears to have appreciated the concern for assuming too low an enrichment for 

interpretation of bioassay mass concentration data, and apparently will address this by correcting 

the default enrichment assumption. NIOSH also stated in a conference call that most bioassay 

data is in activity (not mass) units and, therefore, the enrichment assumption will not be 

important for most intake assessments (Attachment 2, Internal Dose section, question 17). 

SC&A agrees with this, because no conversion from mass to activity is needed in these cases; 

however, for cases that have only uranium mass concentration data, the enrichment assumption 

still remains important. 

5.2	 ISSUE 2: NO DEFAULT ABSORPTION (SOLUBILITY) CLASSES FOR ANY 

OF THE INTAKES ARE IDENTIFIED 

No default absorption (solubility) classes for any of the intakes are identified. Absorption 

classes for two important forms of uranium (UO3 and U3O8) listed are incorrect. There is no 

discussion on high-fired uranium oxides or Special Class Y (S) material that would have 

different biokinetics than traditional Class S uranium compounds. 

The Occupational Internal Dose TBD (Thomas 2006) identifies the absorption classes for the 

principal radionuclides in Table 5-2, and the chemical forms of uranium by location in Table 5-4. 

However, there is no guidance on which absorption classes to assume when assessing intakes 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

33 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

and doses using the default isotopic distribution for intakes shown in Table 5-6. The intakes of 

radionuclides and doses to organs interpreted from bioassay can vary by large amounts when 

different absorption classes are chosen. The guidance on uranium absorption to assume is 

generally adequate; however, there is little discussion on the absorption to choose for plutonium, 

thorium, or technetium that is assumed to be in intakes assessed with the default isotopic 

distribution. 

The TBD does not identify the potential for the UO2 and U3O8 at the site to behave more like the 

Special Class S (Y) material that has an approximately 100-day half-life in the lung and 

excretion parameters more like Class M (W) material (ANSI 1995). There is no discussion on 

whether any high-fired forms of uranium (and/or possibly transuranic radionuclides) existed at 

the site, which may have been more difficult to detect by urine bioassay, and for which fecal 

sampling would have been more applicable. High-fired uranium dioxide is shown in the list of 

absorption classification for some uranium compounds in Table 5-3, but there is no statement in 

the text on its being or not being at the site, and this should be clarified. 

In Table 5-3, the TBD (Thomas 2006) shows UO3 as Class F absorption, yet this is identified by 

the ICRP as Class M, and it also shows U3O8 as being Class M, while the ICRP identifies this as 

Class S (ICRP 1994). Use of the incorrect, more quickly absorbed classes for intake assessment 

of these chemical forms of uranium could lead to significant underestimations of intakes and 

doses to organs. NIOSH needs to correct these absorption identifications before dose 

reconstructors use them or explain the reason for disagreement with the ICRP. 

NIOSH in its response to SC&A’s Internal Dose Section, question 19 (Attachment 3), states the 

following: 

If a claimant has knowledge of the chemical form of the materials with which 

he/she worked, the dose reconstructor will use that information, along with the 

relevant assumptions on monitoring frequency and intake pattern, to reconstruct 

the dose. If information on chemical form, monitoring frequency and intake 

pattern are unknown, the default assumptions described elsewhere in the TBD 

would be applied in a manner which is favorable to claimants. 

It is doubtful that all claimants will know all of the chemical forms of the radionuclides they 

could have been exposed to during their work assignments. Therefore, it is important that 

NIOSH identify default absorption classes that must be assumed for bioassay interpretation in 

cases that applicable process knowledge to a claimant’s case is lacking and/or bioassay data may 

be insufficient in number or sampling frequency for identifying likely absorption classes of 

intakes from modeling. NIOSH’s response appears to show their knowledge of the importance 

of choosing an appropriate claimant-favorable absorption class. However, NIOSH’s lack of 

elaboration or understandable discussion in the TBD on how they will handle this for K-25 

claimants when there is no or insufficient process information for bioassay interpretation leaves 

concern regarding consistency. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

34 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

5.3	 ISSUE 3: THE DEFAULT ISOTOPIC DISTRIBUTION DOES NOT APPEAR TO 

BE CLAIMANT FAVORABLE 

The default isotopic distribution does not appear to be claimant favorable. It does not contain 

Pu-238, Pu-240, or Pu-241. Also, the distribution for Pu-242, Cm-242, and Cm-244 is based on 

the assumption that only low enriched (2%) uranium was present. In addition, the Tc-99 ratio is 

questionably low. 

The Site Description, as well as this Internal Dose TBD (Thomas 2006), describe the use of 

higher enrichments and identify 3% as the predominant enrichment at the site, as discussed in the 

finding above. Also, higher enrichment would lead to higher activity intakes and doses when 

interpreting uranium urine mass concentrations. There needs to be a strong justification for this, 

because it does not appear to be claimant favorable or correct. 

Curium-242 and Cm-244 are identified in Table 5-2 (Thomas 2006) as principal radionuclides 

found at uranium facilities and gaseous diffusion plants; however, these are neither included in 

the default isotopic distribution nor discussed anywhere in the text of the TBD. 

Protactinium-234m is identified in Section 5.4 as one of the progeny of dosimetric interest, yet it 

is not discussed anywhere else in the text, nor is it addressed as part of the default isotopic 

distribution. Plutonium-238, Pu-240, Pu-241, and Pu-242 are isotopes of plutonium that will be 

in any amount of this element taken from a reactor. Since the transuranic radionuclides 

identified in the default isotopic mix are from reprocessed reactor fuel, then these must be part of 

the plutonium isotopes in the contaminants. This is reinforced by the fact that Table 5-5, 

Facility-Specific Radionuclide Conversion Factors, lists all of these with the other radionuclide 

contaminants from the reprocessed fuel. Plutonium-241 has the highest activity of the plutonium 

isotopes per unit mass of uranium at all of the K-25 facilities listed. NIOSH needs to discuss any 

rationale for not adding these radionuclides into the default isotopic distribution. 

The Tc-99 activity concentration in the default isotopic distribution in Table 5-6 (Thomas 2006) 

is a very small fraction of the total uranium activity (very large U:Tc-99 ratio of approximately 

9000:1), which appears to be an underestimate of the potential Tc-99 levels to which claimants 

could have been exposed. Section 5.4 (Thomas 2006) states the following: 

The fission product Tc-99 has also been present during plant operations, 

particularly during the processing of reactor tails. The available documentation 

indicates that the tails contained from 0.041 to 7.0 ppm Tc-99 (Smith 1984, 

Appendix 12; DOE 2000a). 

This indicates that the Tc-99 contaminant levels varied in the source by a factor of at least 175. 

In addition, the Site Description TBD identifies much lower U:Tc-99 ratios, which mean that the 

activity levels of Tc-99 could have been much higher than shown in the default isotopic 

distribution. Statements from the Site Description TBD that support this are as follows: 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

35 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

• Section 2.2, Site Activities and Processes (Thomas 2006): 

In this area, technetium was deposited in many items of equipment. During 

maintenance operations, some of these materials were spilled or released from 

the equipment (some in the gaseous state). This resulted in significant surface 

contamination in Units K-310-1, K-310-2, and K-310-3 of Building K-25 and 

Units K-402-1, K-402-8, and K-402-9 of Building K-27.... Characterization 

studies to date indicate that the observed activity ratio of U:Tc has been as low as 

0.002:1 in these areas. Activity ratios less than 1:1 of U:Tc are common in these 

areas, indicating that 99Tc contamination was significant. 

• Section 2.2.2, Facilities and Support Locations (Thomas 2006): 

K-1420 Decontamination Facility... The observed activity ratio of U:Tc has been 

as low as 0.5:1. 

NIOSH needs to determine if the activity concentration of Tc-99 in the default isotopic 

distribution in Table 5-6 (Thomas 2006) is reasonable and claimant favorable, and why. In 

general, with all of the concerns about the default isotopic distribution, NIOSH should consider 

writing a section or attachment to discuss and defend the development of this issue. 

NIOSH, in its response to SC&A’s Internal Dose section question 12 (Attachment 3), states the 

following: 

At this time, the only facility-specific source term information available is that 

shown in Tables 5-4 and 5-5. The default distribution in Table 5-6 was drawn 

from the same references. If additional source term information should become 

available, the TBD will be revised accordingly, as will the default isotopic 

distribution. (Attachment 3, question 12) 

As pointed out above, NIOSH identified all of the radionuclides that may need to be added into 

the default isotopic distribution in other tables and text in the TBD. NIOSH also provided 

significant information in the Site Description TBD on the varying levels of Tc-99 that could 

have been in source terms. Therefore, it is still not understood why these potential “missing” 

radionuclides and possible higher levels of Tc-99 will not be accounted for. 

In the conference call, NIOSH stated that there is a TIB being developed on RU (Attachment 3, 

Internal Dose section, question 12). According to NIOSH, it is supposed to be released soon and 

addresses RU across the complex. This may answer the questions in this finding. 

5.4	 ISSUE 4: THERE IS GENERAL INCONSISTENCY OR LACK OF COMPLETE 

RADIONUCLIDE INFORMATION FOR FACILITIES IN THE TBD TABLES 

There is a general inconsistency or lack of complete radionuclide guidance and information for 

facilities shown in the tables of the Occupational Internal Dose TBD (Thomas 2006). 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

36 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Several major radionuclides are not shown in source terms at various buildings in Table 5-4, 

Source Term Summary by Location. Table 5-2, Principal Radionuclides Found at Uranium 

Facilities and Gaseous Diffusion Plants, lists Th-230, Am-241, Cm-242, and Cm-244; and the 

default isotopic distribution in Table 5-6 lists Th-230 and Am-241, yet these radionuclides are 

not shown as part of the source term in any buildings listed in Table 5-4. Several facilities 

(K-1410, K-1064, K-1417, K-1419, K-1037, K-1435, K-1015, K-1066, K-1004, K-1006, 

K-1088C) listed in Table 2-2, K-25 Radiological Hazards by Area, of the Site Description TBD 

(Szalinski 2006b) are not covered in Table 5-4 or Table 5-5, Facility Specific Conversion 

Factors. If these non-listed facilities are involved with intakes, NIOSH needs to give further 

guidance on the radionuclide source terms listed. 

NIOSH also needs to address the possibility of intakes of other radionuclides that apparently 

were not bioassay monitored, but were identified during the site expert interviews 

(Attachment 2). Tritium (H-3) may have been in wastes from other DOE sites and were 

disposed of at the TSCA incinerator, which has operated since the 1990s. Radium (which 

produces radon) was identified as having been handled at three facilities (K-1024, K-1030, and 

K-1035), and U-233 was also possibly handled at the site (Attachment 2). Cesium-137 and 

Sr-90 (likely from other Oak Ridge facilities outside of K-25) were found to be contaminants in 

the drinking water, and possibly need to be investigated in the internal dose or environmental 

dose assessments. 

NIOSH, in its response to SC&A’s Internal Dose section questions 10 and 11 (Attachment 3), 

states that, “At this time, the only source term information available is that shown in Tables 5-4 

and 5-5. If additional source term information should become available, the TBD will be revised 

accordingly.” NIOSH appears to recognize the importance of determining accurate source terms 

for buildings; however, it is not understood why the Site Description TBD listing of buildings 

with radiological hazards (Table 2-2) includes several buildings that are not identified in the Site 

Description TBD (Szalinski 2006b). 

5.5	 ISSUE 5: LACK OF INCIDENT INFORMATION MAY BE A PROBLEM FOR 

ACCURACY AND CLAIMANT-FAVORABLE INTERNAL DOSE 

RECONSTRUCTION 

The lack of information on incidents that could have caused significant intakes of radionuclides 

could hinder accurate interpretation of bioassay results and identification of intakes by 

unmonitored or inadequately monitored workers. 

There are no incidents identified in this TBD. There were likely several incidents that have 

incident investigation information that would help dose reconstructors perform accurate and 

claimant-favorable intake and dose assessments. Interpretation of bioassay data can be assisted 

by the use of incident records information and, if no bioassay data are available for an 

unmonitored or inadequately monitored claimant that may have been involved, then other types 

of data from the investigation may be used for dose assessment. The use of medical 

interventions for any major intakes that would have undoubtedly been associated with incidents 

(e.g., chelation for plutonium intakes, bicarbonates for uranium intakes, etc.) that are not 

discussed in this TBD may be found in incident records, and bioassay interpretation can be 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

37 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

assisted by this data. NIOSH needs to determine if an incident records review of greater extent 

needs to be performed, and to justify why it does not need to do this, if it believes it is not 

applicable to reconstructing doses accurately. 

NIOSH, in its response to SC&A’s Internal Dose section, question 4 (Attachment 3), indicates 

that sodium bicarbonate can be used for medical intervention in uranium intake mitigation and, if 

noted in the claimant file, the dose assessment would take this into account. In its response to 

question 6 in Attachment 3, NIOSH reaffirms their TBD statement that no incident information 

is available, and states the TBD revisions in the future may capture these as they are identified by 

claimant interviews or other information sources. This response by NIOSH indicates that they 

are aware that incident information can be valuable for dose reconstruction; however their effort 

to obtain this information appears to be reliant mainly on other parties taking the initiative to find 

and provide it. NIOSH stated in the conference call that if there is a situation where an 

individual claimant states in their CATI that they were involved in an incident, and the dose 

reconstructor does not have enough information in the records provided by the site, NIOSH can 

make a supplemental data request for more data to try to find more information. NIOSH stated 

that there does not seem to be incident documentation at K-25, but there is a system in place to 

pick it up. However, the site expert interviews in Attachment 2 indicate that there should have 

been a lot of records and probably at least one database kept on incidents. 

5.6	 ISSUE 6: COWORKER DATA USE AND APPROACH FOR UNMONITORED 

EMPLOYEES MAY NOT BE APPROPRIATE 

NIOSH’s use of the median bioassay data values from 1948 to 1988 for uranium intake rates and 

1978 to 1988 data for 99Tc intake rates may not be reasonable or claimant favorable for several 

reasons. Because there was undoubtedly some variation of intake rates around the median 

values, it does not appear to be claimant favorable to assume that a claimant’s intake was a 

median intake as opposed to a higher value, such as 84th percentile value. NIOSH needs to 

determine if the work processes (such as production level/throughput), exposure conditions and 

radiological controls (engineering, administrative, personal protective equipment) for the 1945– 

1947 period were similar to the periods that followed. There more than likely were 

improvements to radiological controls as the site progressed over the years; therefore, it appears 

to be a questionable assumption that intake rates during the latter years would have been similar 

to intake rates during the early years. NIOSH also assumes that intakes were chronic; however, 

the Internal Dose TBD (Thomas 2006) states the following in Section 5.5.1, Measurement Types 

and Detection Levels: 

The expected intake pattern in most cases is acute. At K-25, airborne and surface 

contamination was typically controlled to prevent intakes, so most would have 

been the result of unexpected releases. 

NIOSH needs to assess whether acute or multiple acute intakes would provide more claimantfavorable assessments. The urine bioassay data was normalized to 1,400 ml, which is from 

ICRP 23 (ICRP 1974), currently an outdated reference updated with ICRP 89 (ICRP 2002) that 

uses 1,600 ml for a 24-hour excretion volume. Using the current volume would increase the 

bioassay values by more than 10%. The TBD states that only gross alpha results were used to 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

38 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

determine the intake rates, but does not discuss any background adjustment for the gross alpha 

results. If background adjustments were made, this needs to be discussed; if not, it should be so 

stated. 

Also, the guidance for dose reconstructors is vague when it comes to use of coworker data. 

Section 6.9 of the Occupational External Dose TBD (Miles 2006) contains specific guidance for 

dose reconstructors. The third bullet suggests, “In general, assign the maximum reasonable 

coworker dose as a favorable to claimant estimate” (Emphasis added). Guidance is needed to 

avoid individual dose reconstructors selecting their own definition of “reasonable” for this aspect 

of the dose determination. 

NIOSH, in its response to SC&A’s Internal Dose Coworker Data section of Attachment 3, 

question 4, indicates that an individual who was never monitored is assumed to not have the 

potential to have received larger intakes than the majority of those who were monitored, and that 

they assume that the coworker distribution is representative of their intakes. The median dose is, 

therefore, assigned as a lognormal distribution, and the associated GSD is assigned to account for 

possible larger intakes and uncertainty associated with the distribution. This approach is 

reasonable, as long as these assumptions have validity, and the intake scenarios (radiological 

conditions and controls) were not significantly worse in the earlier years. 

NIOSH, in its response to SC&A’s Internal Dose Coworker Data section, questions 1 and 2 

(Attachment 3), indicates that information was not available for determining if air concentrations 

and surface contamination, as well as levels of general radiological control, were different before 

bioassay data are available (pre-1948). NIOSH is using intakes modeled from 1948–1988 to 

estimate the intakes of workers prior to 1948, and states that if the workers “had larger intakes in 

the earlier years their bioassay results would have reflected this in the years that samples were 

collected.” However, NIOSH must be aware that relatively large acute intakes of uranium in 

chemical forms that have fast (Class F) absorption rates (such as UF6, which was the most 

prevalent form at the site) may not be detectable several months or years after initial intakes and, 

therefore, may not be reflected in samples taken this length of time after the intake. If any 

workers had relatively large intakes of Class F chemical forms of uranium in the early years 

(e.g., 1945 or 1946), it is very possible that bioassay in 1948 did not detect or reflect the 

intake(s). In an instance like this, only air samples or surface contamination data would be 

relatively useful for identifying the intake. 

NIOSH, in its response to SC&A’s Internal Dose Coworker Data section, question 3 

(Attachment 3), states that it is not possible to model all intake scenarios, and that the default 

assumption applied across the complex has been to assume chronic intakes. It also points out 

that a chronic intake assumption can be used to approximate small acute intakes. There is no 

doubt that chronic, acute, or a series of either types or combinations of these types of intakes 

could have occurred at this site. The important issue is that NIOSH should have a strong basis 

for using any intake assumption that is not as claimant favorable as any realistic potential intake 

scenario that could be assumed. 

NIOSH stated in the conference call that they do not know if anything has been found on 

radiological controls (Attachment 3, Internal Dosimetry Coworker Data, question 2). Their 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

39 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

approach is to take people who started in the days before monitoring, and look at their bioassay 

results later on. NIOSH assumes that with the slow excretion of uranium, you can take samples 

several years later and still get a relatively reasonable picture of what their exposure has been. 

From this approach, they assumed the same intake rate for each period (before and after bioassay 

started). NIOSH did note that the urine results were pretty steady, and varied up or down by a 

factor of 3 or 4. This still leaves two concerns; (1) the possibility of quicker excretions from 

more soluble form intakes in the early years that could go undetected, and (2) since there is some 

variation observed, choosing the median value projections may not be a reasonable claimantfavorable approach. 

5.7	 ISSUE 7: URANIUM CYLINDER STORAGE YARD DOSE MAY BE 

UNDERESTIMATED AND NEUTRON DOSE MAY HAVE BEEN MISSED 

The K-25 Occupational Environmental Dose TBD (East 2006) states that, “Uranium cylinder 

storage yards remain the only significant source of external exposure at K-25. Surveys in 

cylinder yards at the sister plants show dose rates up to 200 mrem/2000h.” It also states that, 

“The ORR Annual Environmental Report for 2003 (DOE 2004) reports a dose from the K-25 

cylinder yards to a nearby parking area at 4.75 mrem/125h (75 mrem/2000h).” The PGDP 

Occupational Environmental Dose TBD (East 2004) states the following: 

Unmonitored workers in the early years did not have significant inventories of 

depleted uranium to contribute to external dose. Later, unmonitored workers 

would not spend their entire work year at the depleted cylinder yards and, 

therefore, would not reach the maximum dose recorded by fence line monitoring. 

No other significant sources of external exposure are associated with the PGDP 

operations. An assumed deep dose equivalent rate of 200 mrem/yr for all years 

would be reasonable, and deficiencies in earlier measurement techniques thereby 

become immaterial. 

The recommended 200 mrem/2,000 hr for the PGDP is quoted in the K-25 TBD, yet 

75 mrem/2,000 hr is used as the K-25 recommended external dose from the uranium cylinder 

yards. It is also reasonable to assume that doses in a nearby parking area would be less than 

doses nearer to the cylinder storage yards. NIOSH should evaluate the advisability of using the 

PGDP-recommended 200 mrem/2,000 hr as the basis for a more claimant-favorable dose 

estimate for K-25 workers. 

In addition, Bechtel Jacobs published a report in May 2000 entitled, Evaluation of Potential 

Radiation Doses to Members of the Public and ETTP Unmonitored Site Workers, East Tennessee 

Technology Park, Oak Ridge, Tennessee, BJC/OR-585/R1 (BJC 2000), to evaluate exposures 

from the K-25 cylinder yards. The report concluded that an unmonitored site worker who may 

spend 250 hours in a year (1 hour per work day) close enough to several cylinder yards could 

receive 125 mrem. These individuals are able to access the radiological posted areas present 

inside the fencing to get close enough to areas with potential exposure rates exceeding 

0.4 mrem/hr. This exposure rate includes exposure to both gamma and neutrons using a 

conservative 4:1 gamma-to-neutron dose ratio. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

40 of 191 

 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Section 6.7.3 of the TBD states that the neutron dosimeters in use “were generally insensitive to 

the low neutron dose rates at K-25...” In addition, the dosimeters were insensitive to any dose 

rate due to neutrons below the NTA cutoff (somewhere between 1.0 and 0.5 MeV). In spite of 

this, dose reconstructors are instructed to add missed neutron dose only for workers in the 

cylinder yards. There will have been pervasive, low-level neutron fields in other areas of the 

plant, due to the alpha-N reaction, spontaneous fission, the presence of trace levels of 

transuranics in some feed stocks and incidents or “slow cooker” (Cardarelli undated–circa 1966) 

events. Given these facts, SC&A recommends that all areas of the plant be evaluated to 

determine an appropriate missed dose component for neutron exposure. 

5.8	 ISSUE 8: UNTIL 1980, SOME DOSIMETERS WERE ONLY PROCESSED 

UPON REQUEST RESULTING IN AMBIGUITY REGARDING THE 

CONSTRUCTION OF DOSES IN THE EARLY YEARS 

The Occupational External Dose TBD (Miles 2006, pg. 9) stated the following: 

K-25 began operations in 1945 using dosimeter and processing technical support 

provided by the Oak Ridge National Laboratory (ORNL). ORNL, then the Clinton 

Laboratory, had implemented its dosimetry methods based on the personnel 

beta/photon dosimeter design developed at the Metallurgical Laboratory at the 

University of Chicago (Pardue, Goldstein, and Wollan 1944). ORNL provided 

K-25 with beta/photon film dosimeters and neutron nuclear track, type A (NTA) 

emulsion. 

The TBD (Miles 2006, pg. 10) also made the following declaration: 

From 1945 to 1979, ORNL processed dosimeters only on request. 

There is, however, no discussion as to the meaning of this statement. It is unclear from these two 

statements whether dosimeters were routinely processed for workers or only done in some 

random frequency. If the latter is true, many workers may have missed dose, due to lack of 

processing or recording. A key question is whether the practical determination to process a 

badge was based on an expected reading above the lower limit of detection (LLD) or above the 

weekly allowable dose, or some other action level. This information is vital in order to assess 

the validity of the coworker database. 

SC&A recommends that this issue be investigated and data collected in situations such as the 

percentage of issued badges that were processed, the procedures for selecting which badges to 

process, the procedures for handling positive results, the implementation of a QA program (if 

any), etc. 

5.9	 ISSUE 9: CHRONIC NEUTRON EXPOSURE OPPORTUNITIES MAY HAVE 

BEEN OVERLOOKED 

The TBD contains the statement that there was minimal potential for significant neutron doses. 

In the same paragraph, it states that doses ranged up to “less than 0.05mSv/hr.” These seemingly 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

41 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

low fields could give rise to a 10 rem/yr dose to a worker who spent a full work year in this field, 

not even accounting for x, beta, and gamma (2,000 hours × 0.05 mSv/hr = 100mSv). It appears 

that the authors may have assumed that certain areas, processes, operations, or equipment did not 

pose a hazard, when perhaps they did. SC&A suggests that this issue be revisited, and a 

determination made as to whether some categories of workers could have been exposed to 

chronic low-level neutron fields. (In addition, did workers routinely work more than 

40 hrs/week? If so, then chronic dose rates have an even greater impact.) 

For health physics and safety coverage during the early years, it seems that little attention was 

paid to the possibility of neutron exposures. While it is possible that this was because there were 

no significant neutron fields, there is another more likely scenario—limited staff, inexperience, 

inadequate instrumentation, and a generally more relaxed attitude to chronic exposure levels— 

may have resulted in safety staff overlooking or ignoring neutron exposure potential. In a 

contemporaneous health physics and safety review in the 1950s (HPSO 1954), there is no 

mention of potential neutron exposures, yet alpha, beta, and gamma hazards are discussed. 

Given what we now know regarding neutron exposure, due to slow cooker events and in the 

cylinder yard, and that the NTA dosimeters worn at the time would have missed most or all of 

the neutron exposures, potential neutron dose cannot be simply disregarded. 

SC&A suggests that this issue should be revisited and a determination made as to whether some 

categories of workers could have been exposed to chronic low-level neutron fields. 

5.10	 ISSUE 10: POTENTIAL EXPOSURE TO TC-99 BETA WERE NOT RECORDED 

BY DOSIMETERS AND ARE NOT ADDRESSED IN THE TBD 

Section 6.5.4 of the Occupational External Dose TBD (Miles 2006) discusses potential beta 

exposure from Tc-99 (294 keV endpoint). It is recognized that TLD dosimeters that were used 

for part of the site history would not detect these betas. It is also likely that the film badges used 

in the 1945 to 1979 period did not detect Tc-99. (Details on wrapping and cover materials in 

mg/cm2

 would be helpful.) It is asserted that only skin contamination could have given rise to 

significant beta exposure due to Tc-99, yet this claim is unsupported by any discussion of typical 

quantities of Tc-99 that might be present, or any measurements or calculations of dose rates. 

Note that, although the wrapping on the dosimeter would completely adsorb the technetium 

betas, they are still more than capable of penetrating 7mg/cm2 to deliver skin dose. 

There is evidence from other gaseous diffusion sites that problems can arise where substantial 

external exposure is possible. For example, in 1968 at Paducah (a sister facility), an incident was 

reported where workers were exposed to a significant unsuspected beta field from Tc-99 (BJC 

1968a, BJC 1968b). Resultant skin doses of up to 36 rem were recorded. 

The potential for exposure to beta fields needs to be more fully evaluated, with a parallel 

consideration of the dosimetry in use at the time and the potential for unreported or underreported dose. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

42 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

5.11	 ISSUE 11: RELIANCE ON A SINGLE NEUTRON-TO-PHOTON RATIO FOR 

THE ENTIRE PLANT IS QUESTIONABLE 

Reliance on a single neutron-to-photon ratio for the entire plant geography and history that 

additionally is based on a measurement at another facility is questionable. The K-25 plant had a 

number of potential sources of neutron exposure that will have varied over time as processes, 

facilities, procedures, impurities, and enrichments changed. Section 6.5.4 of the Occupational 

External Dose TBD (Miles 2006) describes the process by which the ratio was derived. 

Measurements at Paducah during a cylinder-painting project are construed to be applicable to the 

entire depth and breadth of K-25 operations. This seems to be unlikely, given that K-25 went 

through several upgrades, utilized virgin and recycled feed, and was an experimental facility to 

some extent. 

The choice of this neutron-to-photon ratio is significant, since the entire dosimetry record (based 

on NTA film) will be completely disregarded, due to the NTA low-energy cut-off in the energy 

region likely to be of concern at K-25 (Miles 2006, Section 6.7.3). 

Additional research and analysis is recommended to evaluate the neutron-to-photon ratio(s) that 

should be used to estimate missed neutron doses over the K-25 plant history. SC&A 

recommends that careful consideration be given to situations where the photon component of the 

field may have been effectively shielded by process equipment and pipe work, leaving a neutron 

component of exposure that is not accompanied by a significant photon component. This would 

undermine the application of the ratio method for these situations. 

5.12	 ISSUE 12: ALL BETA DOSIMETRY WAS BASED ON A URANIUM SLAB 

CALIBRATION 

The Occupational External Dose TBD (Miles 2006, pg. 16) states the following: 

...beta calibrations were routinely performed using a slab of uranium, the 

primary source of shallow dose at K-25. No adjustment to recorded dose from 

the dosimeter is recommended. 

While energetic uranium betas may well have been the predominant source of beta exposure at 

the site, it is recognized that Tc-99 was also present, concentrated, and collected as part of the 

process. The TBD does not give any insight into this process, however. Given that it is likely 

that at least some workers were routinely exposed to Tc-99, and given that the dosimeters will 

have partly or completely missed this lower-energy beta, SC&A recommends that an evaluation 

be performed to determine the degree to which Tc-99 dose was under-reported or missed 

entirely. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

43 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

5.13 SECONDARY ISSUES 

5.13.1 Secondary Issue 1: There is a Lack of Guidance on Bioassay Interpretation 

There is a lack of guidance on bioassay interpretation. The TBD needs to either provide more 

specific guidance to the dose reconstructor on several parameters that must be chosen or adjusted 

for intake and dose assessment, or reference the documents that will provide this guidance. 

In Section 5.5.3, Instructions for Addressing Possible Interferences and Uncertainties (Thomas 

2006), the following is stated: 

The practice of offsite collection of samples that takes place approximately 24 to 

48 hours after leaving the plant not only minimizes the possibility of sample 

cross-contamination, but it ensures that samples are collected after the transfer of 

the rapid clearance component. Some K-25 employees were asked to collect 

samples after 1 or 2 days off from work; if so, that collection instruction was 

sometimes noted in the analytical record. 

The next paragraph states the following: 

Urine samples were typically collected in the workplace at K-25. Therefore, 

contamination of samples from worker’s hands or clothing cannot be ruled out as 

a contributor to any given result. If a second analysis was performed and if that 

result was negative, sample cross-contamination could have occurred during first 

collection. 

This information is apparently conflicting and confusing. If the author is discussing two separate 

eras of sampling, then it should be noted. Another issue is ruling out an intake with a second 

analysis (presumably from a second bioassay sample, i.e., follow-up or special bioassay). The 

TBD (Thomas 2006) does not identify that a calculation (modeling) should be performed to 

determine if an intake could have occurred that would not have been detectable by a second 

bioassay. Such a bioassay could easily take several days after the first sample, which would be a 

more claimant-favorable approach. Another issue that appears unresolved regarding the 

sampling methods was the use of spot urine samples. Spot urine samples have a greater 

variability than 24-hour samples, and a determination for any needed adjustment to these results 

should be made (Medley et al. 1994). 

NIOSH, in its response to SC&A’s Internal Dose section, question 13 (Attachment 3), states the 

following: 

As described in Section 5.5 of the TBD, urine samples were collected as both 

“spot” samples and as 24-hour collections, with the latter the standard procedure 

after 1950. If the measurement results are given in units of concentration, the 

dose reconstructors will convert them to 24-hour-equivalent excretion rates by 

using the Reference Man volume in ICRP Publication 23. If results are given in 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

44 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

units of activity only, a 24-hour collection may be presumed if the date of the 

analysis is after 1950 (Attachment 3, question 13). 

NIOSH should elaborate on any needed adjustments for the greater variability of spot urine 

sample concentrations when interpreting spot urine data, per the reference cited above. It also 

should consider using the replacement to ICRP Publication 23 (ICRP 1974), which is ICRP 

Publication 89 (ICRP 2002), which identifies larger 24-hour excretion volumes. This would 

increase 24-hour-equivalent uranium excretion rates proportionally and likely increase doses for 

urine bioassay concentration data. 

In Section 5.6.3, Instructions for Addressing Possible Interferences and Uncertainties (Thomas 

2006), there is a statement regarding in-vivo bioassay interpretation: 

For in-vivo measurements, contamination could have occurred as external to the 

body or, in the case of chest counting, as external to the lung. If a follow-up 

in-vivo count (the same day or within a few days) showed a dramatic decrease in 

activity or no detectable activity, then external contamination should be assumed. 

This should be qualified with a statement that a determination of a possible intake of a form of 

the radionuclide with short lung retention must be made to be claimant favorable, particularly 

when urine bioassay is available. 

There is little guidance on addressing the potential situation of a claimant having multiple intakes 

of different absorption classes, which could increase the complexity of the bioassay data 

interpretation. Also, if lung absorption/solubility analysis was performed on any of the materials 

at the site, this information needs to be made available to the dose reconstructors if the data 

warrants adjustment to the modeling input parameters or applicable biokinetic models. There is 

very little discussion on background subtraction for gross alpha counting or alpha spectrometry 

for isotopic uranium in urine. If there is going to be any adjustment for background 

radionuclides in urine, this should be discussed and defended in detail, because it will have a 

significant affect on interpreting these results. According to Attachment A of the K-25 

Urinalysis Codes (Definitions) 1948–1988, Attachment A (Wallace 2005), describing the 

bioassay database, sampling frequency varied from monthly to semi-annually. There should be 

some discussion on the default assumed intake dates with these wide-ranging sampling 

frequencies when there is not enough bioassay data to determine most likely intake dates from 

modeling. 

NIOSH, in its response to SC&A’s Internal Dose section question 2 (Attachment 3), states the 

following: 

When assessing intakes based on uranium urinalyses, our standard procedure has 

been to assume that the entire result is due to occupational exposure... No 

background subtraction is performed. 

This is a reasonable claimant-favorable approach and NIOSH should ensure that it is consistently 

followed, in light of its statement within the TBD that interpretation of results can be difficult 
 

Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

45 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

because of the contribution of environmental uranium. In its response to SC&A’s Internal Dose 

section question 15 (Attachment 3), NIOSH states the following: 

The frequency of sampling as a programmatic issue is not a useful piece of 

information; the worker sample results are in the DOE files so the required 

frequency is irrelevant after the fact. Because uranium is long-lived and long 

retained, a dose reconstruction can be performed with very few results. 

Uranium is not retained for long periods if it is in chemical forms that have fast (Class F) 

absorption rates, such as UF6, which was the most prevalent form at the site. Relatively large 

intakes could have gone undetected for acute intakes that may have occurred many weeks before 

a urine sample was taken if the claimant did not provide a timely urine sample. This is most 

significant with the bioassays that were analyzed for uranium mass concentration by fluorimetry 

(pre-1989), which had a much higher MDC than more recent analytical methods. The intake 

date assumption can be critical when modeling acute intakes and the TBD (Thomas 2006) should 

be clear on directions for intake date assumption, or refer to other ORAU procedural documents 

that clearly provide the necessary guidance. 

5.13.2 Secondary Issue 2: There is No Comparison between Measured and Predicted 

Environmental Dose 

The PGDP Occupational Environmental TBD, ORAUT-TKBS-0019-4 (East 2004), states that 

since 1962, “At PGDP all personnel wore film badges...” The ORNL Occupational 

Environmental TBD, ORAUT-TKBS-0012-4 (Burns 2004), states that, “ORNL went to a takehome badge (i.e., security badge and dosimeter combined) in the early 1950s...” It is reasonable 

to postulate that given similar activities to a sister site (PGDP) and being a part of the Oak Ridge 

Reservation (ORR), K-25 employed a similar personnel dosimetry arrangement for workers, as 

well. A comparison between personnel dosimetry data (measured), with estimates based on 

ambient environmental exposures (predicted), would prove useful to validate the methods for 

reconstructing external environmental doses. 

5.13.3 Secondary Issue 3: The TBDs do not provide a Consistent Time Period for the 

Processing of RU at K-25. 

The Site Description TBD (Szalinski 2006, Section 2.2, Site Activities and Processes) states the 

following: 

Processing of recycled uranium from spent reactor fuel was intermittent, with 

campaigns conducted in 1952 to 1964, 1969 to 1974, and 1976 and 1977. 

The Site Description TBD then states the following (Section 2.2.1, K-25 Processing History): 

1964 to 1985 

In 1964, Buildings K-25 and K-27 were shut down, with the exception of K-25 

purge cascade and its pigtail operation. In 1968, part of Building K-29 was shut 
 

Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

46 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

down. The bottom of the cascade was now in Building K-31. ORGDP processed 

reactor returns through 1984, and continued to receive product from PGDP for 

use as feed. 

The Occupational Internal Dose TBD (Thomas 2006, Section 5.3, Scope, pg. 6, footnote 2) states 

the following: 

The predominant enrichment level was 3.0%. Reprocessed fuel was used as feed 

from 1952 until 1976. At that time, the cascade facilities were upgraded and most 

of the TRU and fission product materials were removed. Campaigns involving 

reprocessed fuel elements ended in the 1980s. 

Then the Occupational Internal Dose TBD (Section 5.4, Source Term) states the following: 

Certain TRU isotopes have been present at K-25 including 237Np, and 239Pu. 

These resulted from the processing of reactor tails. Reactor tails were fed to the 

cascade from 1953 to 1964, and again from 1969 to 1976, with the exception of 

1971 when none of the feed was of reactor origin (Smith 1984, pg. 9). 

These statements in the two TBDs make it somewhat difficult to determine an appropriate ending 

date for the potential of exposure to the radionuclide contaminants in RU during processing 

work. It appears that 1976, 1977, 1984, and “the 1980s” are identified as ending dates. The 

potential radionuclide contaminants in the RU (Tc-99, Np-237, Pu-238, Pu-239, Pu-240, Pu-241, 

Pu-242, Am-241, Cm-242, and Cm-244) can give a significant increase in the dose from intakes 

of RU process material compared to natural uranium ore sources that do not contain these 

radionuclide contaminants. The Occupational Internal Dose TBD (Thomas 2006) does identify a 

default isotopic distribution that contains some of these contaminants. The default isotopic 

distribution is assumed for intakes in Table 5-6. However, the TBD text does not clarify the 

years to assume for this default. The TBD should identify specific time periods that RU and its 

default isotopic distribution are to be assumed in intake assessment. This is not consistent with 

current guidance, and may not be claimant favorable. 

In the conference call (Attachment 4, Internal Dosimetry, question 9), NIOSH stated that all 

intakes of uranium will assume that RU was involved from 1952 through the present, and will 

use the default isotopic distribution in the Internal Dose TBD for assessed intakes (Thomas 2006, 

Table 5-6). 

5.13.4 Secondary Issue 4: The TBD Does Not Adequately Define Frequency and Assess 

All Types of X-rays in Occupational Medical Exposure. 

Initial guidance on medical exposure and dose guidelines, as presented in Revision 2 of 

ORAUT-OTIB-0006 (Kathren 2003), provides basic guidelines that the dose reconstructor can 

use to ensure that all occupational medical exposures are reasonably included in determining the 

overall dose estimations for claimants. Although the conference call with NIOSH 

(Attachment 4) indicated that dose reconstructors were using these guidelines, the latest 

Occupational Medical Dose TBD (Turner 2006) does not provide information that the updated 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

47 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Revision 3 of ORAUT-OTIB-0006 (Kathren and Shockley 2005) is being used. The 

Occupational Medical Dose TBD (Turner 2006) assumes an interpretation that has been also 

considered and applied at other sites, such as the Mound Plant, the Los Alamos National 

Laboratory (LANL), Paducah, and Pinellas. It is assumed that occupationally related medical 

exposures are included in dose reconstruction for pre-employment, annual, health monitoring 

examinations, and post-employment chest x-rays. There is no indication in the TBD that a 

review of individual medical records (particularly in the early years, where medical data is on 

microfiche) has been conducted to verify the frequency of chest x-rays in the early years, and 

what the appropriate number of chest x-rays for inclusion in dose reconstruction is for workers 

exposed to uranium dust. This would need to be developed for those workers whose individual 

medical records do not document the frequency of chest x-rays. Table 3.1 (Turner 2006, pg. 7) 

points out in the footnotes to that table that during 1944–1945, some workers with the potential 

for exposure to uranium dust received monthly chest x-rays, while uranium dust workers 

between 1946 and 1959 received chest x-rays every few months. Although NIOSH has stated 

that they rely on the K-25 Site to provide all medical record information (Attachment 4), an 

interview with a K-25 medical x-ray technologist working there since 1975 (Attachment 2, 

Medical X-ray Procedures section), indicated that the data provided may not contain information 

retired to microfiche. In the early period, workers with potential for exposure to uranium dust 

inhalation were reported in the TBD (Turner 2006, Table 3-1) to have often received monthly 

chest x-rays. NIOSH needs to review the microfiche to verify the frequency of chest x-rays in 

the early years for claimants, and what the appropriate number of chest x-rays for inclusion in 

dose reconstruction is for workers exposed to uranium dust. This would need to be developed 

for those workers whose individual medical records do not document the frequency of chest 

x-rays. 

The TBD (Turner 2006) does indicate that the reconstruction of occupational dose should 

include all occupational x-rays according to the frequency listed in Table 3.1, unless the 

individual-specific frequency is known and is more frequent than that in Table 3.1 (Turner 2006, 

pg. 7). 

If the dose reconstructor, as a general rule, assumes only one annual chest x-ray, this would 

substantially underestimate some workers’ medical exposure. In the more recent documentation 

in Revision 3 of ORAUT-OTIB-0006 (Kathren and Shockley 2005), it is concluded that other 

examinations should be included, such as special screening exams (e.g., respiratory protection, 

beryllium workers, asbestos workers, food handlers, etc., and termination examinations). The 

TBD does not address assigned dose for these special chest x-rays. 

The Occupational Medical Dose TBD (Turner 2006) does not refer the dose reconstructor to 

either the earlier version (Revision 2) of ORAUT-OTIB-0006 (Kathren 2003) or to the updated 

Revision 3 (Kathren and Shockley 2005). Revision 2 assumes that special chest radiography for 

respirator certification, beryllium workers, asbestos workers, and food handlers are accomplished 

as part of the routine physicals. This is not documented in the Occupational Medical Dose TBD. 

Another factor not discussed in the TBD is the potential and impact of x-ray procedures utilized 

by medical authorities to do special screenings that are performed outside the frequency 

suggested in the TBD or at alternate locations. The ORR had numerous sites, and contracted 

with numerous radiology services and hospitals that provided these services upon request. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

48 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

It is also known that Oak Ridge did upper GI fluoroscopy and lumbar spines up through 1953; 

however, no specific recommendation is given to dose reconstructors on how to incorporate 

these types of x-rays into the dose reconstruction process. It is suggested that the policy during 

1960 to 1979 was to assume that radiation workers were given one annual chest x-ray. From 

1980 to 2002, that frequency was reduced to one chest x-ray every 5th year for radiation workers. 

But nothing is documented regarding a policy covering the frequency of these exams. To the 

contrary, there is ample evidence that chest x-rays were often provided on a voluntary basis to 

nearly all workers, usually on an annual basis from 1944 to 1959 (Turner 2006, Table 3.1, pg. 7). 

The majority of workers had chest x-rays annually as a routine at DOE sites until the mid-1980s, 

when Federal guidelines warning against routine screening were first being enforced. 

NIOSH made the decision to limit occupational medical exposure to those chest exams and 

frequencies described above, except for some lumbar spine exams in 1950 to 1953, and to 

include all other exposure as part of worker non-occupational medical dose. SC&A believes 

such an interpretation is not claimant favorable to those most at risk. Our concern is that 

specified “high-risk” workers, those most likely exposed to radiation and beryllium, would be at 

risk of having an incomplete dose assessment if not all radiation associated to medical screening 

for job-related activities were included. Since all radiation provides some risk, and arguably, is 

cumulative, workers warrant consideration of all forms of work-related x-ray exposure to be 

claimant favorable. SC&A believes NIOSH should review its interpretation of included medical 

exposure, and should reasonably adopt a broader interpretation in the K-25 Occupational 

Medical TBD of occupational medical dose, as provided in the most recent version of ORAUTOTIB-0006 (Kathren and Shockley 2005). 

5.13.5 Secondary Issue 5: Techniques and Protocols Increase Uncertainty of Dose 

Conversion Factors Listed in the TBD 

The Occupational Medical Dose TBD (Turner 2006) fails to describe adequately all the 

information upon which to establish beam quality for x-ray units in use from 1943. The TBD 

relies on Publication 34 (ICRP 1982) to provide that data: 

ICRP (1982) provides tables of average absorbed dose (mGy) in selected organs 

for selected X-ray projections at 1 Gy entrance kerma (i.e., air kerma without 

backscatter) for selected views and selected beam qualities [i.e., various halfvalue layers (HVLs)]. These tables list the basic dose conversion factors for 

converting air kerma to organ dose. Air kerma was obtained from Table 3.2-1 

for machine, view, and period by assuming R = cGy (kerma). This assumption is 

conservative (Turner 2006, pg. 5). 

The TBD goes on to point out additional information organ dose and assumed collimation prior 

to 1979. Table 3.3 (Turner 2006, pg. 8) lists organ doses based on Publication 34 (ICRP 1982) 

equations. The TBD points out that the results of Table 3.3 assume poor collimation prior to 

1970, which means that some organs are included in the primary beam that would not normally 

be included had the beam been properly collimated. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

49 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

The TBD describes the type of x-ray machines used at K-25: 

Two X-ray machines were used at K-25 during the 1940s and 1950s: (1) a 

General Electric (GE) Model KX-10 Photoroentgen X-ray machine, used 

primarily for photofluorography of the chest, and (2) a Westinghouse 200-mA 

X-ray machine, used with an adjustable table and fluoroscopic attachment to 

examine extremities, spine, hips, skull, shoulder, and other nonthoracic locations. 

The Westinghouse machine, which produced the now-conventional 14-in. x 17-in. 

chest X-ray, was primarily a backup to the GE machine (Cardarelli 2000) 

(Turner 2006, pg. 5). 

...The K-25 site used only the conventional PA chest X-ray technique for routine 

examinations after the early 1950s, which substantially reduced radiation doses 

per examination. In 1962, a Westinghouse 300-mA machine replaced the 200-mA 

machine. Additional X-ray exposure was introduced in the early 1970s when the 

health monitoring program added a lateral (LAT) chest view to the routine chest 

X-ray examination procedure (Cardarelli 2000). In 1987, a Westinghouse 

500-mA X-ray unit replaced the 300-mA machine. Routine PA and LAT chest 

views were performed through 2000 (Turner 2006, pg. 6). 

The TBD (Turner 2006, pg. 7) has provided a very helpful table (Table 3.2) that lists each 

type of x-ray equipment and also includes the following data: 

• kVp (kV) 

• Assumed HVL (mm Al eq) 

• Image size in inches 

• Entrance Skin Exposure PA (cGy) 

• Entrance Skin Exposure LAT (cGy) 

It is pointed out in the TBD that the values in Table 3.2 are used for obtaining air kerma, 

and that the entrance skin exposures (ESEs) are all from actual measurements made and 

documented in the literature (Turner 2006, pg. 6). 

The TBD acknowledges that occupational medical dose is the largest part of worker dose: 

....workers might have received their largest occupational doses from the 

required medical X-ray examinations. The amount of dose received depends on 

the type of equipment, the technique factors, and the number of examinations 

typical in the early years (Cardarelli 2002). K-25 medical records include 

notations in individual worker files regarding the date and the purpose of the of 

X-ray examinations (Turner 2006, pg. 6). 

In the absence of definitive tube output measurements, the TBD directs the use of default values 

and dose conversion factors (DCFs) derived from ICRP Publication No. 34 (ICRP 1982). These 

values are then applied to determine organ doses using Tables A.2 through A.8 of ICRP Report 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

50 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

No. 34 (ICRP 1982). An issue of concern is that the DCFs are derived using a default half-value 

layer of 2.5 mm Al for Type 1 units in use from 1946–1980. 

The Occupational Medical Dose TBD (Turner 2006) provides little documentation to support the 

assumed techniques and protocols applied to calculate the dose, which is mainly derived from 

ICRP Publication 34 (ICRP 1982). The TBD provides the following summary on the use of PA 

and LAT chest x-rays: 

The K-25 site used only the conventional PA chest X-ray technique for routine 

examinations after the early 1950s, which substantially reduced radiation doses 

per examination... Additional X-ray exposure was introduced in the early 1970s 

when the health monitoring program added a lateral (LAT) chest view to the 

routine chest X-ray examination procedure (Cardarelli 2000) (Turner 2006, 

pg. 6). 

It is an undocumented assumption in the TBD that exams required only a PA view. SC&A has 

inquired whether definitive protocol existed to validate that chest exams possibly included PA 

views and LAT views on a limited basis. NIOSH has acknowledged in other TBD reviews that 

the lack of verifiable protocols is a generic problem at many sites, has planned to search all 

available records, and will include pertinent records and references in any future revision of this 

section of the TBD. The Occupational Medical Dose TBD is also deficient in that little 

documentation exists to validate x-ray protocols, equipment maintenance, and upkeep records. 

5.14 REVIEW OF TECHNICAL SUPPORT DOCUMENTS 

5.14.1 Review of Internal Coworker Data for K-25, ORAUT-OTIB-0035 

For K-25 workers that may have had occupational internal dose from intakes of radionuclides, 

but were not monitored for the intakes or were inadequately monitored, NIOSH has calculated 

estimated intake rates for uranium and Tc-99 based upon analysis of coworker bioassay data, as 

described in ORAUT-OTIB-0035 (Cherry 2006). NIOSH followed the processes for this 

analysis described in ORAUT-OTIB-0019, Analysis of Coworker Bioassay Data for Internal 

Dose Assignment (Brackett 2004) and ORAUT-PLAN-0014, Coworker Data Exposure Profile 

Development (ORAUT 2004). Although their approach is generally consistent for unmonitored 

or inadequately monitored worker assessments, there are potential weaknesses, inaccuracies, and 

assumptions made that could result in dose calculations that are not claimant favorable. 

NIOSH is using intakes modeled from 1948–1988 to estimate the intakes of workers prior to 

1948, and states that if the workers “...had larger intakes in the earlier years, their bioassay 

results would have reflected this in the years that samples were collected” (Attachment 3, 

questions 1 and 2). However, NIOSH must be aware that relatively large acute intakes of 

uranium in chemical forms that have fast (Class F) absorption rates (such as UF6, which was the 

most prevalent form at the site) may not be detectable several months or years after initial 

intakes. Therefore, these acute intakes of uranium may not be reflected with any sensitivity in 

samples taken several years after the intake. If any workers had relatively large intakes of 

Class F chemical forms of uranium in the early years (e.g., 1945 or 1946), it is very possible that 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

51 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

bioassay in 1948 did not detect or reflect the intake(s). In an instance like this, only air-sample 

or surface-contamination data would be relatively useful for identifying the intake. 

NIOSH, in its response to SC&A’s Internal Dose Coworker Data section, question 4 

(Attachment 3), indicates that an individual who was never monitored is assumed to not have the 

potential to have received larger intakes than the majority of those who were monitored. NIOSH 

assumes that the coworker distribution is representative of their intakes; the median dose is, 

therefore, assigned as a lognormal distribution, and the associated geometric standard deviation 

(GSD) is assigned to account for possible larger intakes and uncertainty associated with the 

distribution. The use of the median bioassay data values from 1948 to 1988 for uranium intake 

rates, and 1978 to 1988 data for Tc-99 intake rates, may not be reasonable or claimant favorable. 

Because there was undoubtedly some variation of intake rates around the median values, it does 

not appear to be claimant favorable to assume that a claimant’s intake was a median intake, as 

opposed to a higher value, such as the 84th percentile value (+1 standard deviation). 

NIOSH, in its response to SC&A’s Internal Dose Coworker Data section, question 3 

(Attachment 3), states that it is not possible to model all intake scenarios, and that the default 

assumption applied across the complex has been to assume chronic intakes. It also points out 

that a chronic intake assumption can be used to approximate small acute intakes. There is no 

doubt that chronic, acute, or a series of either types or combinations of these types of intakes 

could have occurred at this site. The important issue is that NIOSH should have a strong basis 

for using any intake assumption that is not as claimant favorable as any realistic potential intake 

scenario that could be assumed, and defend the use of such intake assumptions. 

NIOSH stated in the conference call that they do not know if anything has been found on 

radiological controls (Attachment 4, Internal Dosimetry Coworker Data, question 2). Their 

approach is to take people who started in the days before monitoring and look at their bioassay 

results in later years. NIOSH assumes that with the slow excretion of uranium, you can take 

samples several years later and still get a relatively reasonable picture of what their exposure has 

been. From this approach, they assumed the same intake rate for each period (before and after 

bioassay started). NIOSH did note that the urine results were pretty steady, with variations of 

only a factor of 3 or 4. Besides the fact that reviewing any available radiological control 

information (such as air sampling and surface contamination data) could be helpful in 

determining potential intakes of unmonitored workers, this bioassay interpretation approach still 

leaves two concerns; (1) the possibility of quicker excretions from more soluble form intakes in 

the early years that could go undetected, and (2) since there is some variation observed, choosing 

the median value projections may not be a reasonable claimant-favorable approach. 

During the conference call, it was determined that NIOSH had not found any fecal sample data 

for the site (Attachment 4, Internal Dose, question 2). They were informed that a report was 

found during the site visit that identified a fecal-sampling program used from 1964 to 1966 at the 

Uranium Recovery Facility (Schultz 1966). This report was sent to NIOSH for review to 

determine if it has any information that could be useful for a future revision of the coworker data 

document. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

52 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

There were also a few strengths seen in the internal dosimetry coworker document. The 

assumption of U-234 contributing 100% of the uranium isotope activity in the intake was 

claimant favorable, due to having a higher dose factor for this isotope than for U-235 and U-238. 

Directing dose reconstructors to add the other radionuclides (plutonium, neptunium, etc.) in the 

default isotopic distribution identified in the Internal Dose TBD (Thomas 2006) to all uranium 

intakes after start of processing RU is important. The guidance to run dose calculations with 

each uranium absorption rate (F, M, S) to determine which gives the largest dose to the organ 

and POC is appropriate. The document was also consistent with other site coworker internal 

dosimetry approaches. 

5.14.2 Review of External Dosimetry Coworker Data for K-25, ORAUT-OTIB-0026 

Until approximately 1980, few of the dosimeters issued at the K-25 Site were processed. Thus, 

the coworker data that is developed in ORAUT-OTIB-0026 (Merwin 2006) is significant and 

will play a role in the dose determination for many workers. 

The doses that are assigned in the database are based on a composite of limited measurements 

and an assignment of the LOD/2 entered in place of missing or null results, as required in 

ORAUT-OTIB-0020 (Merwin 2005). As discussed in the external dosimetry section 

(Finding 5.8), it is not entirely clear when and how dosimeters were pulled for processing. 

Therefore, the entire database for coworkers is based to a great extent on an unknown group of 

(presumably) higher exposure individuals, coupled with a large component attributable to the 

LOD/2. 

A concern arises in the guidance provided to dose reconstructors in Section 7, item 5, of 

ORAUT-OTIB-0026 (pg. 8). The dose reconstructor is required to determine whether a worker 

was in one of the following three categories: 

...unlikely to have been exposed..., or 

...Exposed to intermittent low levels of radiation..., or 

...routinely exposed... 

Based on the dose reconstructor’s judgment, a choice is made to use the onsite ambient dose, the 

50th percentile, or the 95th percentile as a best estimate of the worker’s dose. This is counter to 

the requirement for dose calculations to follow a prescriptive approach. This concern is 

discussed in detail in the SC&A report, The Review of NIOSH/ORAU Procedures and Methods 

Used for Dose Reconstruction, Supplement 1 (Behling 2006). NIOSH should develop a 

prescriptive approach to this issue that enables the dose reconstructor to categorize the worker 

without the routine need for personal judgment. 

There is a concern with the development of the shallow dose table (Merwin 2006, Table 2). The 

process of deriving the data for the table resulted in zero values for the non-penetrating 

component of dose for 19 of the 41 years the table addresses. The TIB describes the issue on 

page 10: 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

53 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

...With the methodology described above, null values for non-penetrating dose 

can occur because of the subtraction of the reported penetrating doses from the 

reported shallow doses and the favorable to claimant method described above to 

establish coworker doses based on the addition of potential missed doses. 

However, a “zero” value in Table 2 for non-penetrating dose will not result in a 

dose of zero being assigned to an organ such as the skin. For example, the 

50th percentile dose to the skin in 1948 would be assigned entirely as 0.780 rem of 

photons. This approach does not result in an underestimation of probability of 

causation (which is determined by the Department of Labor) because assigning 

beta dose as gamma dose in IREP has no negative effect, since the radiation 

effectiveness factors are the same for >15 keV electrons and >250 keV photons, 

and are higher for 30–250 keV photons (Merwin 2006, pg. 10). 

This issue is dismissed as unimportant, as it is stated that IREP will automatically assign the 

penetrating dose to the non-penetrating input. This may well be technically appropriate at the 

present time; however, this assumption would collapse were NIOSH to modify IREP in the 

future and change this particular programming rule. NIOSH should correct the table to ensure 

that a modification of IREP does not inadvertently cause the system to fail with regard to nonpenetrating dose calculations. In this reviewer’s opinion, the reliance on the current design of a 

software program as a method of ensuring the accuracy of input data from a very different 

component of the overall dose reconstruction system is a weak quality link. 

There are two areas where the TIB will provide a significantly claimant-favorable approach. 

First, as discussed in the final paragraph of Section 7.0 of the TIB, the annual doses show a 

marked decline once actual dosimetry results are used in place of estimates. Although doses 

might be expected to decline slightly when dosimeter processing is first ramped up due to 

increased worker and management awareness, the reduction by factors ranging by 5 to 10 signify 

that the estimates were crafted conservatively. 

The second area where a conservative approach has been taken is in the use of the system-wide 

modifying factor for construction workers, as laid out in ORAUT-OTIB-0052 (Chew et al. 

2007), and incorporated in the November 2006 version of ORAUT-OTIB-0026 (Merwin 2006). 

This TIB reviewed a number of sites and a system-wide adjustment factor of 1.4 was adopted for 

construction workers. This is claimant favorable for K-25, which was a selected site for the 

review. The data shows that the construction worker doses were bounded by the total worker 

dose for every year of K-25 operation except one. Therefore, for all other years, the coworker 

dose assigned for construction trades will automatically be increased by a factor of 1.4, despite 

the fact that the data shows that this is not required for K-25. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

54 of 191 

 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

6.0	 OVERALL ADEQUACY OF THE SITE PROFILE AS A BASIS FOR 

DOSE RECONSTRUCTION 

The SC&A procedures call for both a “vertical” assessment of a site profile for purposes of 

evaluation-specific issues of adequacy and completeness, as well as a “horizontal” assessment 

pertaining to how the profile satisfies its intended purpose and scope. This section addresses the 

latter objective in a summary manner by evaluation of (1) how, and to what extent, the site 

profile satisfies the five objectives defined by the Advisory Board for ascertaining adequacy; 

(2) the usability of the site profile for its intended purpose, i.e., to provide a generalized technical 

resource for the dose reconstructor when individual dose records are unavailable; and (3) generic 

technical or policy issues that transcend any single site profile that need to be addressed by the 

Advisory Board and NIOSH. 

6.1 SATISFYING THE FIVE OBJECTIVES 

The SC&A review procedures, as approved by the Advisory Board, require that each site 

profile be evaluated against five measures of adequacy—completeness of data sources, 

technical accuracy, adequacy of data, site profile consistency, and regulatory compliance. 

The SC&A review found that the NIOSH site profile (and its constituent TBDs) for K-25 

represents an adequate accounting of the primary internal issues related to plutonium, 

uranium, polonium, and tritium exposures, as well as main external hazards from the 

reactor and accelerator facilities. The K-25 Site Profile falls short in fully characterizing 

a number of key underlying issues that are fundamental to guiding dose reconstruction. 

In some cases, these issues may impact other site profiles. Many of the issues involve 

lack of sufficient conservatism in key assumptions or estimation approaches, or 

incomplete site data or incomplete analyses of the data. Section 6.0 summarizes the key 

issues. Detailed evaluation of these issues is provided elsewhere in the report. 

6.1.1 Objective 1: Completeness of Data Sources 

The breadth of data sources used as a basis for the K-25 Site Profile is evident in the 420 

documents for the K-25 Site in the Site Profile Research Database. One hundred and three 

reports (103) were cited in the site profile references, while others served to provide confirmatory 

information. The NIOSH/ORAU team consulted health physics personnel with long histories at 

K-25 who have extensive knowledge of key dosimetry historical processes and personnel 

monitoring data. 

The SC&A review of the K-25 dosimetry records cited in the site profile from the standpoint of 

their adequacy and completeness, as well as their inclusion of known sources of K-25 worker 

radiation dose information, indicates a lack of verification on the part of NIOSH to ensure 

records provided by the site are complete. Interviews with K-25 workers have uncovered some 

additional sources of personal radiation exposure that may not routinely be provided by the K-25 

Site to NIOSH for individual claimants (Attachment 2). K-25 has limited the information 

provided to NIOSH from the individual medical records to x-ray reports and, in some cases, 

incident information. All this data is directly relevant and should be reflected in dose 

reconstruction. Finally, while accidents and incidents are listed in the site profile, the site profile 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

55 of 191 

 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

does not fully address the significance of such incidents, how they may have contributed to 

worker dose, and how they would be addressed by dose reconstruction. 

The hierarchy of data used in the dose reconstruction process begins with the use of individual 

monitoring data as a priority. This is fundamental to the performance of dose reconstruction. 

The K-25 Site typically contains hardcopy internal and external monitoring results, personal 

contamination records, secondary dosimetry results, whole-body count reports, etc., but lacks 

mention of incident reports. The individual monitoring data provided to NIOSH, as cited by the 

site profile and applied in dose reconstruction, are pulled from these records at K-25. 

6.1.2 Objective 2: Technical Accuracy 

The site profile does not adequately address data insufficiency for impact and implications to 

early worker dose reconstruction. Information available for dose reconstruction in the early 

years is limited, inadequate, or in some cases, not available. The Occupational Internal Dose 

TBD (Thomas 2006, pg. 6) states that, “Data are available from 1952 to the present for both in 

vivo and in vitro analysis records and associated interpretations.” It appears, therefore, that the 

approach is to use data from 1952 or later to assign dose for the pre-1952 period. This needs to 

be better clarified in the Internal Dose TBD. This may entail the use of a hypothetical chronic 

intake for uranium and any other radionuclides where bioassay data are unavailable. The 

bioassay monitoring appears to be limited to workers directly handling radionuclides, or had not 

been developed. The Occupational Internal Dose TBD points out the following: 

The primary method for monitoring employees for intakes of radionuclides at 

K-25 was urine bioassay. Bioassay monitoring was instituted at the start of 

enrichment operations and has continued to the present. However, the focus of 

the monitoring program in the very early years was the detection of excreted 

soluble uranium. When monitoring for less soluble isotopes of uranium and TRU 

elements was necessary, in vivo methodologies were implemented, primarily 

whole-body counting and chest (lung) counting (Thomas 2006, pg. 6). 

The TBD (Thomas 2006) lacks guidance on bioassay interpretation. The current TBD does not 

consistently address potential internal dose from radionuclides such as Pu-238, Pu-241, Pu-242, 

Cm-242, and Cm-244, and possibly other radionuclides that were brought up in the site expert 

interviews, if these existed at K-25 as the interviewees reported (Attachment 2). As pointed out 

earlier, there is a general inconsistency or lack of complete radionuclide guidance and 

information for facilities, as shown in the tables of the TBD. In an effort to address both internal 

and external coworker dose for unmonitored workers, NIOSH/ORAU has provided two technical 

information bulletins for use by the dose reconstructor; ORAUT-OTIB-0026 (Merwin 2006) 

provides guidance for external coworker dosimetry data for the K-25 Site, and ORAUT-OTIB0035 (Cherry 2006) similarly provides guidance for internal coworker dosimetry data for K-25. 

A number of deficiencies were identified with the Internal Dose TBD (Thomas 2006) related to 

inadequate consideration of exposure and missed dose, where SC&A questions the premise of 

the approach. This was borne out by information provided by K-25 Site Expert interviewees 

(Attachment 2, Missed Dose section). Exposure to a number of these radionuclides was not 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

56 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

given adequate, or in some cases, any consideration in the Internal Dose TBD, although some are 

listed as facility-specific radionuclides handled in particular technical areas. The completeness 

of results for uranium and plutonium is uncertain. No default absorption (solubility) classes for 

any of the intakes are identified in the TBD. The TBD (Thomas 2006, Table 5.2, pg. 8) does 

point out that the primary radionuclides found at uranium facilities and gaseous diffusion plants 

are Th-230, U-234, U-235, U-236, U-238, Pu-238, Pu-239/240, Np-237, Cm-242, Cm-244, 

Am-241, and Tc-99. Further research into the potential exposures from these radionuclides is 

needed to determine which workers may have been exposed, the quantities they were exposed to, 

and the potential internal doses from intakes. 

The Occupational Internal Dose TBD (Thomas 2006) lacks a clear means to assign dose to 

unmonitored workers. Radionuclides used at K-25 are not well characterized, and this can make 

it difficult to find the data needed for claimant-favorable dose reconstruction. 

The current methodology outlined in the Occupational External Dose TBD (Miles 2006) may 

result in an underestimate of neutron dose. Neutron dose is determined from NTA film results 

and is modified with a correction factor. The TBD fails to address the neutron detection cutoff 

for the NTA film that occurs below 1 MeV. The TBD makes the following general assumption: 

Workers at the K-25 site, especially those employed during peak production in the 

1950s, 1960s, and 1970s, were exposed to radiation types and energies associated 

with natural and recycled uranium enrichment processes (Miles 2006, pg. 8). 

In regard to energy ranges the TBD mentions the following: 

In most areas at K-25, the majority of the photon dose is attributable to photons 

in the 0.06- to 0.25-MeV range, energies at which dosimeters will overestimate 

exposure, reported in units of roentgen (Miles 2006, pg. 8). 

In many areas at K-25, the primary cause of photon doses during normal 

operations was gamma rays from 235U, with primary photon energies ranging 

from 144 to 205 keV. This is particularly true in areas where enriched uranium 

was present (with a higher than natural abundance of 235U). The photon 

dose rate from uranium is proportional to the level of enrichment (Miles 2006, 

pg. 11). 

The energies of major radiation emissions at K-25 are provided in Table 6-3, page 12 of the 

TBD. From the above information, it appears that the entire spectrum is essentially below the 

practical 1-MeV detection limits of NTA film used in the workers’ badges. The TBD is 

confusing, however, in regards to the upper energy levels at K-24, in that it also states the 

following: 

The neutron energies at K-25 are between 0.1 and 2.0 MeV, for which the ICRP 

Publication 60 radiation-weighting factor is 20 (ICRP 1990). The associated 

dose correction factor is 1.91, which is rounded to 2. Dose reconstructors should 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

57 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

apply this factor to both measured neutron dose equivalent and missed neutron 

dose equivalent (Miles 2006, pg. 13). 

The Occupational Medical Dose TBD (Turner 2006) provides little documentation to support 

that the assumed techniques and protocols applied to calculate the dose, which are mainly 

derived from Cardarelli et al. 2002, are accurate. NIOSH believes that when no information is 

readily available about the energy spectrum, it is reasonable to use the assumptions for DCFs that 

are presented in the Implementation Guide (OCAS 2002). 

The Occupational Medical Dose TBD (Turner 2006) does consider the potential contribution to 

dose that may have resulted in less than optimal use of collimation by stating the following: 

The results of Table 3-3 assume poor collimation prior to 1970, which means that 

some organs are included in the primary beam that would not normally be had 

the beam been properly collimated (Turner 2006, pg. 7). 

For K-25, NIOISH refers the dose reconstructors to the estimated organ doses for PA and 

LAT chest X-rays, “...based on the dose conversion factors in ICRP (1982)” (Turner 

2006, pg. 6). The TBD goes on to state the following: 

These tables list the basic dose conversion factors for converting air kerma to 

organ dose. Air kerma was obtained from Table 3-2 for machine, view, and 

period by assuming R = cGy (kerma). This assumption is conservative 

(Turner 2006, pp. 6–7). 

Unresolved is the concern that the DCFs are derived from ICRP (1982) and, therefore, are not 

comparable in terms of beam quality, which varies from unit to unit. These factors can 

contribute greatly to the dose to the chest and other organs for units in operation prior to 1985, 

where little documentation exists. 

As written, the Occupational Environmental Dose TBD (East 2006) fails to test the adequacy of 

evaluating the cumulative (additive) effect of numerous source terms at differing locations. 

Interviews of retired K-25 personnel (see Attachment 2) suggest that essential data, as far back as 

1958, does exist. SC&A believes that the lack of air monitoring stations, within a particular 

building at the K-25 Site of known higher releases of a specified isotope, does not readily enable 

one to accurately estimate environmental dose, using air monitoring data, from an adjacent 

building air monitoring station. It will be difficult for the dose reconstructor to accurately 

estimate environmental dose without accurate air monitoring data derived from a station 

proximal to the release point. 

6.1.3 Objective 3: Adequacy of Data 

Questions regarding data adequacy have largely focused on the adequacy of early occupational 

monitoring data. The potential for unmonitored intakes was significant from 1945–1948 for site 

workers. In the absence of early bioassay data prior to 1948, the Occupational Internal Dose 

TBD (Thomas 2006) provides the dose reconstructor with little guidance. There is a large 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

58 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

amount of uncertainty in calculation of early internal doses resulting from inadequate or 

incomplete monitoring data, including air concentration data, which casts doubt on the feasibility 

to reconstruct internal dose prior to the establishment of routine, reliable bioassay methods. 

The Occupational External Dose TBD (Miles 2006) states the following: 

During the early years, only workers entering controlled areas and likely to 

receive measurable dose received dosimeters. Beginning in 1951, dosimeters 

were issued to the entire work force as part of the security badge, although only 

those likely to have received measurable dose were processed. Beginning in 

1980, all dosimeters were processed....Various radiation dose concepts and 

quantities have been in use to measure and record occupational dose since the 

initiation of the MED in the early 1940s. The basis of comparison for 

reconstruction of dose is the Personal Dose Equivalent, Hp(d), where d identifies 

the depth (in millimeters) and represents the point of reference for dose in tissue 

(Miles 2006, pg. 5). 

The TBD does provide discussion on handling of missed dose by stating the following: 

Watson et al. (1994) examined methods analysts can consider when there is no 

recorded dose for a period during a working career. The missed dose for 

dosimeter results less than the MDL is particularly important for earlier years 

when MDLs were higher and dosimeter exchange was more frequent. NIOSH 

(2002) describes options to calculate missed dose for this situation. The 

preferred option estimates a claimant-favorable maximum potential missed dose 

as (MDL)/2 multiplied by the number of zero-dose results (Miles 2006, pg. 13). 

SC&A has concerns related to the measurement of early exposures and the consistency in which 

they were documented. 

6.1.4 Objective 4: Consistency among Site Profiles 

An extensive comparison was performed by SC&A to compare and contrast the methodologies 

used in the K-25 Site Profile and other site profiles reviewed to date. These comparisons focus 

on the methodologies and assumptions associated with dose assessments and the derivation of 

values used to obtain a POC for individual claimants. 

The site description provides a comprehensive evaluation of activities that occurred at the 

different technical areas, and some of the potential hazards associated with these operations. 

This valuable data is not carried through to the other TBDs, such as the Environmental Dose and 

Internal Dose TBDs. 

SC&A notes that the K-25 Site Profile TBDs do not address the significant exposure potential 

that existed for individuals that worked around the cascades when they were open. The Paducah 

Site Description TBD (Turpin 2006) brings this out as a significant source of worker exposure. 

It is most likely that the K-25 Cascades presented a similar potential for high external dose and 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

59 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

may have represented a potential for significant internal dose, particularly for workers exposed to 

the cascade dust. 

There were two cascade improvement/upgrade programs at PGDP – the Cascade 

Improvement Program (CIP) and the Cascade Upgrade Program (CUP). The 

first ran from 1958 to 1962 and the second from 1973 to 1981. These programs 

were significant because of possible worker exposure to transuranic (TRU) 

elements while the cascade systems were open. 

The Paducah Site Description (Turpin 2006, pp. 17 and 20–21) went on to note the 

following: 

Operations Performed in the Cascade Buildings and Maximum Radionuclide 

Concentrations Expected (Bechtel Jacobs 2001): 

Cascade operations – 1953–1964, 1969–1970, and 1972–1976 

450 ppb Np-237 

0.09 ppb Pu-239 

23,000 ppb Tc-99 

Moderate external radiation exposure potential 

Cascade maintenance (cascade dust) – 1954–1961 and 1973–1981 (CIP/CUP) 

2,740 ppb 239Pu-239 

3,220,000 ppb 237Np-237 

Specific concentrations of Tc-99 not available for this operation 

High external radiation exposure potential 

Operations Performed in Building C-409 and Maximum Radionuclide 

Concentrations Expected (Bechtel Jacobs 2001): 

Cascade maintenance – 1954–1961 and 1973–1981 (CIP/CUP)
 

450 ppb Np-237 

0.09 ppb Pu-239 

Specific concentrations Tc-99 not available for this operation 

High external radiation exposure potential.
 

SC&A recommends that any updates to the K-25 TBDs provide a section that addresses this 

significant potential for exposure from work around the K-25 Site open cascades, and that dose 

reconstructors ensure that dose received during work around the cascades is included in the 

claimant’s dose reconstruction. 

The basic default values assigned for determining medical exposure are relatively consistent 

among site profiles. The site profiles do not always apply the same revision of ORAUT-OTIB0006, as is the case with the K-25 Site Profile, which was not corrected in the most recent 

November 7, 2006 revision of the TBD (Turner 2006). Other deviations from the standard 

assumptions are based on site-specific information. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

60 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

The Y-12 (Murray 2006), SRS (Scalsky 2005), and Hanford (Shockley and Kathren 2005) 

Occupational Medical Dose TBDs base their default exposure geometry on the compensability or 

non-compensability of the claim. The Mallinckrodt Chemical Worker (MCW) (Westbrook 

2005) and Rocky Flats Plant (RFP) (Furman and Lopez 2004) Occupational Medical Dose TBDs 

based default exposure geometries on job titles. The ORNL (Fleming 2004), LANL (Johnson 

2004), and the Idaho National Engineering and Environmental Laboratory (INEEL) (Rohrig 

2004) Occupational Medical Dose TBDs choose to default to 100% Anterior-Posterior (AP) 

exposure. The K-25 Occupational Medical Dose TBD (Turner 2006) is silent on the use of the 

default of 100% Anterior-Posterior (AP) exposure by the dose reconstructor. Further evaluation 

of exposure geometry for photon and neutron exposure should be evaluated for K-25 workers to 

determine if 100% AP geometry is appropriate for all K-25 workers. NIOSH should consider 

development of a consistent default assumption for exposure geometry in all site profiles. 

Review of site profiles to date indicates that the NIOSH/ORAU team has not come to a 

consensus on what components should be considered in the environmental dose. The analysis 

considered internal dose from onsite atmospheric radionuclide concentrations, limited evaluation 

of internal dose from resuspended soil, and ambient external exposure. 

The K-25 Occupational Internal Dose TBD (Thomas 2006) does not present radionuclide 

components of the uranium source term in a similar manner as identified in the Paducah 

Occupational Internal Dose TBD (Mantooth 2006), Table 5-2. The Paducah TBD has identified 

Pu-241 and Pu-242 as contributors to this source term (from RU), whereas the K-25 TBD has 

missed these two contributors in its default isotopic distribution. The in-vitro measurement 

methods section of the Paducah TBD (Mantooth and Barton 2007) provides a table of bioassay 

frequencies used at the site throughout its history. A similar table in the K-25 TBD would also 

be helpful for internal dose assessment. The Paducah TBD also identifies several incidents with 

internal dose potential, which apparently was not accomplished in the K-25 development effort. 

The recommended 200 mrem/2,000 hr for the PGDP is quoted in the K-25 TBD, yet 

75 mrem/2,000 hr is used as the K-25 recommended external dose from the uranium cylinder 

yards for K-25. 

The SRS TBD (Scalsky 2005) distinguishes neutron energies and neutron-to-photon ratios for 

reactors, fuel fabrication, plutonium production, and radionuclide production and calibration. 

The INEEL External Dose TBD (Rohrig and Bump 2006) considers the reactors, the processing 

plant, waste-handling operations, calibration sources, and uranium handling. Neutron energy 

spectra and neutron-to-photon ratios for Pu-238 and P-239 operations are segregated at SRS 

(Scalsky 2005). The categories used in the K-25 TBD lack the detailed analyses seen in other 

TBDs. 

The K-25 Occupational External Dose TBD (Miles 2006) does not spend much time discussing 

the potential impact of differing exposure geometries on worker dose, and only offers the 

following: 

Examinations of the beta, photon (X-ray and gamma ray), and neutron radiation 

type, energy, and geometry of exposure in the workplace, and the characteristics 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

61 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

of the K-25 dosimeter responses are crucial to the assessment of bias and 

uncertainty of the original recorded dose in relation to the radiation quantity 

Hp(d). Dose reconstructors can compare earlier dosimetry systems to current 

systems to evaluate their performance, based on the premise that current systems 

have more stringent criteria, as indicated in the DOELAP and NVLAP programs 

(Miles 2006, pg. 6). 

The K-25 operation was large and complex, the building being the world’s largest for a time. 

There is a dearth of information relating to the operations and how they evolved over several 

decades. There are almost no maps, diagrams, or flow charts provided. The Pinellas Site Profile 

is a study in contrasts. Detailed drawings, photographs, and maps are provided, with lists of 

equipment incorporated and site incidents tabulated. The K-25 Site Profile should be improved 

to provide as much detail as possible, as was done for Pinellas (Orr and Demopoulos 2006). 

6.1.5 Objective 5: Regulatory Compliance 

SC&A reviewed the site profile with respect to Objective 5, which requires SC&A to evaluate 

the degree to which the site profile complies with stated policy and directives contained in 

42 CFR Part 82. In addition, SC&A evaluated the TBDs for adherence to general quality 

assurance policies and procedures utilized for the performance of dose reconstructions. NIOSH 

has complied with the hierarchy of data required under 42 CFR Part 82 and its implementation 

guides. As mentioned above, quality assurance with respect to claimant-specific information is 

lacking, and further consideration should be given to evaluating records provided by sites, and 

how the requests for these records are communicated to the sites. In essence, if something is not 

explicitly requested, it will not be provided. 

6.2 USABILITY OF SITE PROFILE FOR INTENDED PURPOSES 

SC&A has identified seven criteria that reflect the intent of the EEOICPA and the regulatory 

requirements of 42 CFR Part 82 for dose reconstruction. Because the purpose of a site profile is 

to support the dose reconstruction process, it is critical that the site profile assumptions, analytic 

approaches, and procedural directions be clear, accurate, complete, and auditable (i.e., 

sufficiently documented). SC&A used the following seven objectives to guide its review of the 

K-25 Site Profile TBDs to determine whether it meets these criteria: 

Objective 1 − Determine the degree to which procedures support a process that is expeditious 

and timely for dose reconstruction. 

Objective 2 − Determine whether procedures provide adequate guidance to be efficient in select 

instances where a more detailed approach to dose reconstruction would not affect the outcome. 

Objective 3 − Assess the extent to which procedures account for all potential exposures, and 

ensure that resultant doses are complete and are based on adequate data. 

Objective 4 − Assess procedures for providing a consistent approach to dose reconstruction, 

regardless of claimants’ exposures by time and employment locations. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

62 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Objective 5 − Evaluate procedures with regard to fairness and the extent to which the claimant is 

given the benefit of the doubt when there are unknowns and uncertainties concerning radiation 

exposures. 

Objective 6 − Evaluate procedures for their approach to quantifying the uncertainty distribution 

of annual dose estimates that is consistent with and supports a Department of Labor (DOL) POC 

estimate at the upper 99% confidence level. 

Objective 7 − Assess the scientific and technical quality of methods and guidance contained in 

procedures to ensure that they reflect the proper balance between current/consensus scientific 

methods and dose reconstruction efficiency. 

6.2.1 Ambiguous Dose Reconstruction Direction 

Direction provided in the site profile as a stand-alone document can be confusing, and in some 

cases, directions are inconsistent throughout a particular TBD. With the supplemental TIBs in 

the case of internal coworker dosimetry data (Cherry 2006), external coworker dosimetry data 

(Merwin 2006), and internal dose estimates for facilities with air sampling programs (Brackett 

and Bihl 2005), the approach is somewhat more clearly defined. 

The conditions for application of environmental dose to K-25 employees are not clearly defined 

in the introduction of the Environmental Dose TBD, as is usually the case with other TBDs. 

There are recommendations for usage throughout the TBD, but concrete direction for which 

workers receive environmental dose is lacking. 

Radon was specifically addressed in the MCW (Westbrook 2004) and the Fernald Internal Dose 

TBD (Rich 2004), where K-65 residues with high concentrations of Ra-226 were handled, yet 

the K-25 Occupational Internal Dose TBD indicates on page 5 that NIOSH does not consider 

naturally occurring radon present in conventional structures to be an exposure to be 

occupationally derived. The K-25 Internal Dose TBD (Thomas 2006) does not address potential 

radon exposure in the workplace as a contributor to dose. 

6.2.2 Inconsistencies and Editorial Errors in the Site Profiles 

There is an inconsistency between the Site Description TBD (Szalinski 2006b) and Occupational 

Internal Dose TBD (Thomas 2006) regarding the time when RU processing ended (1976, 1977, 

or 1984). 

6.3 UNRESOLVED POLICY OR GENERIC TECHNICAL ISSUES 

A number of issues were identified that are common in the K-25 and other site profiles reviewed 

to date and, in some cases, represent potential generic policy issues that transcend any individual 

site profile. These issues may involve the interpretation of existing standards (e.g., oro-nasal 

breathing), how certain critical worker populations should be profiled for historic radiation 

exposure (e.g., construction workers and early workers), and how exposure itself should be 

analyzed (e.g., treatment of incidents and statistical treatment of dose distributions). NIOSH 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

63 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

indicates that it may develop separate TIBs in order to address these more generic issues. The 

following represents those issues identified in the K-25 and previous site profile reviews that, in 

SC&A’s view, represent transcendent issues that need to be considered by NIOSH as unresolved 

policy or generic technical issues. 

(1) Direction on the applicability of the TBD and/or TIBs to individual dose reconstructions 

is absent. 

(2) Mobility of the work force between different areas of the site should be addressed. Site 

expert testimony that many workers moved from one plant to the next is a complicating 

factor. Establishment of an accurate worker history is crucial in such cases. This will be 

especially difficult for family member claimants. 

(3) Statistical techniques used in the application of the data to individual workers should be 

further considered and substantiated. 

(4) Dose from impurities and/or daughter products in radioactive material received and 

processed at sites should be assessed as a contributory exposure source. 

(5) The significance of various exposure pathways and the assumptions made that influence 

dose contributions need to be considered (most notably) for solubility, oro-nasal 

breathing, and ingestion. 

(6) Analysis needs to be performed regarding how “frequent or routine incidents” should be 

addressed, given the possibility that such “spike” exposures often may be missed by 

routine monitoring as a function of how often and in what manner it was conducted. 

(7) Availability of monitoring records for “transient or outside workers,” e.g., subcontractors, 

construction workers, and visitors, who may have potential exposure while working on or 

visiting a facility should be ascertained. 

(8) Dose to decontamination and decommissioning workers should be assessed. Many 

facilities have large-scale decontamination and decommissioning (D&D) operations, 

which extend back many years. Decontamination and decommissioning (D&D) 

operations often require working in unknown situations, which may provide unique 

exposure situations. 

(9) Dose reconstruction for occupational medical exposures remains incomplete. NIOSH 

needs to reconsider the definition to include all forms of radiation medical exposure, to 

ensure its considerations are claimant favorable. 

(10) Dose reconstruction for workers involved in nuclear weapons testing who were employed 

by a site other than the test site. 

(11) Quality Assurance on records provided by the site to the NIOSH/ORAU team is 

necessary to ascertain whether complete information is being provided. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

64 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

REFERENCES 

42 CFR Part 82, Title 42, Public Health, Part 82, Methods for Radiation Dose Reconstruction 

Under the Energy Employees Occupational Illness Compensation Program Act of 2000, Code of 

Federal Regulations, May 2, 2002. 

ANSI (American National Standards Institute) 1995, Bioassay Programs for Uranium, HPS 

N13.22-1995, Washington, DC. 

BJC (Bechtel Jacobs Company), 1968a, Report of Investigation of Beta Exposure Incident at 

Cylinder Wash Facility C-400, Report No. KYB114, Union Carbide Corporation, Nuclear 

Division, Paducah Plant, April 16, 1968. 

BJC (Bechtel Jacobs Company), 1968b, Report of Conclusions and Recommendations or Beta 

Exposure Incident at Cylinder Wash Facility C-400, Report No. KYB115, Union Carbide 

Corporation, Nuclear Division, Paducah Plant, April 16, 1968. 

BJC (Bechtel Jacobs Company) 2001, Recycled Uranium Mass Balance Project Paducah 

Gaseous Diffusion Plant Site Report, BJC/PGDP-167 DRAFT, prepared for the DOE Office of 

Environmental Management. 

Behling, V. H., 2006, SCA-TR-TASK3 Supplement 1, Rev. 0, Draft June 2006, The Review of 

NIOSH/ORAU Procedures and Methods Used for Dose Reconstruction, Supplement 1 , S. Cohen 

and Associates, June 2006. 

BJC (Bechtel Jacobs Company) and Haselwood Enterprises, 2000, Recycled Uranium Mass 

Balance Project, Oak Ridge Gaseous Diffusion Plant (Currently Known as East Tennessee 

Technology Park) Site Report BJC/OR-584, East Tennessee Technology Park, Oak Ridge, 

Tennessee. [SRDB Ref ID 16497] 

Brackett, E. M., 2004, Technical Information Bulletin – Analysis of Coworker Bioassay Data for 

Internal Dose Assignment, ORAUT-OTIB-0019, Rev. 00, Oak Ridge Associated Universities, 

Oak Ridge, Tennessee, December 29, 2004.
 

Brackett, E.M., and Bihl, D.E., 2005, Internal Dose Overestimates for Facilities with Air 

Sampling Programs, ORAUT-OTIB-0018, Revision 01, Oak Ridge Associated Universities, Oak 

Ridge, Tennessee, August 9, 2005. 

Burns, R. E., 2004, Technical Basis Document for the Oak Ridge National Laboratory – 

Occupational Environmental Dose, ORAUT-TKBS-0012-4, Rev. 00, Oak Ridge Associated 

Universities, Oak Ridge, Tennessee, May 7, 2004. 

Cardarelli, J. J., Undated, Health Hazard Evaluation Report 96-0198-2651, Portsmouth Gaseous 

Diffusion Plant, Piketon, Ohio, Health-Related Energy Research Branch, Division of 

Surveillance, Hazard Evaluation and Field Studies, National Institute for Occupational Safety 

and Health, undated. (Circa 1996) 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

65 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Cardareilli, J. J., 2000, A Potential Consequence of Excluding Work Related X-Ray Exposures 

When Computing Occupational Radiation Dose as a Uranium Enrichment Plant, Dissertation, 

University of Cincinnati, Ohio. 

Cardarelli, J. H., Spitz, C., Rice, C, Buncher, R. Elson, H., and Succop, P., 2002, Significance of 

Radiation Exposure From Work-Related Chest X-Rays for Epidemiological Studies of Radiation 

Workers, Amer. J. of Indust. Med. 42-490-501. 

Cherry, R. N. 2006, Internal Dosimetry Coworker Dosimetry Data for the K-25 Site, OTAUTOTIB-0035, Rev. 00 PC-1, Oak Ridge Associated Universities, Oak Ridge, Tennessee, July 21, 

2006. 

Chew, M. H., Devanney, J. A., Faust, L. G., Morris, R. L, and Potter, E. W., 2007, Parameters to
 

Consider when Processing Claims for Construction Trade Workers, ORAUT-OTIB-0052, Rev. 

00 PC-1, Oak Ridge Associated Universities, Oak Ridge, Tennessee, January 16, 2007. 

Close, P. J., 1945, Determination of Policy on Gases of Exposure to Occupational Disease, 

Memorandum to Major G. A. Tamey, Jr., Army Services Forces, United States Engineer Office, 

Manhattan District, Oak Ridge, Tennessee, July 26, 1945. 

Demopoulos, P.J. 2004, Technical Basis Document for Portsmouth Gaseous Diffusion Plant – 

Occupational Internal Dose, ORAUT-TKBS-0015-5,Rev. 00, Oak Ridge Associated 

Universities, Oak Ridge, Tennessee, November 24, 2004. 

DOE (U.S. Department of Energy) 2000a, Phase II – Independent Investigation of the Paducah 

Gaseous Diffusion Plant – Environment, Safety and Health Practices, 1952–1990, Office of 

Oversight, Environment, Safety and Health, Washington, DC. 

DOE (U.S. Department of Energy) 2000b, Independent Investigation of the East Tennessee 

Technology Park, Volume 1: Past Environment, Safety and Health Practices, Office of 

Oversight, Environment, Safety and Health, October 2000. 

DOE 2004, Oak Ridge Reservation Annual Site Environmental Report for 2003, Oak Ridge 

National Laboratory, U S. Department of Energy, Washington DC, September 2004. 

East, J., 2004, Technical Basis Document for the Paducah Gaseous Diffusion Plant – 

Occupational Environmental Dose, ORAUT-TKBS-0019-4, Rev. 00, Oak Ridge Associated 

Universities, Oak Ridge, Tennessee, August 24, 2004. 

East, J., 2006, Technical Basis Document for the K-25 Site – Occupational Environmental Dose, 

ORAUT-TKBS-0009-4, Rev. 00 PC-1, Oak Ridge Associated Universities, Oak Ridge, 

Tennessee, September 26, 2006. 

Fleming, K., 2004, Technical Basis Document for the Oak Ridge National Laboratory – 

Occupational Medical Dose, ORAUT-TKBS-0012-3, Rev 01, Oak Ridge Associated 

Universities, Oak Ridge, Tennessee, October 29, 2004. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

66 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Furman, J. and Lopez., T., 2004, Technical Basis for Rocky Plants Plant – Occupational Medical 

Dosimetry, ORAUT-TKBS-0011-3, Rev. 00, Oak Ridge Associated Universities, Oak Ridge, 

Tennessee, February 9, 2004. 

HPSO, 1954, Health Physics and Safety Organizational Overview, K/EM-109, ORF00986, 

E.0503.034.0670, July 13, 1954. 

ICRP (International Commission on Radiological Protection) 1974, Reference Man, Publication 

23, Pergamon Press, Oxford, England. 

ICRP (International Commission on Radiological Protection) 1982, Protection of the Patient in 

Diagnostic Radiology, Publication 34, Pergamon Press, New York, New York. 

ICRP (International Commission on Radiological Protection) 1990, 1990 Recommendations of 

the International Commission on Radiological Protection, Publication 60, Annals of the ICRP, 

Volume 21, Numbers 1–3, Pergamon Press, Oxford, England. 

ICRP 1994 (International Commission on Radiological Protection) 1994, Human Respiratory 

Tract Model for Radiological Protection, ICRP Publication 66, Pergamon Press, Oxford, 

England. 

ICRP (International Commission on Radiological Protection) 2002, Basic Anatomical and 

Physiological Data for Use in Radiological Protection: Reference Values, Publication 89. 

Annals of the ICRP, 32(3-4). Oxford: Elsevier Science, Ltd. 

Ikenberry, T. A. 2006, Internal Dosimetry Coworker Data for the Paducah Gaseous Diffusion 

Plant, ORAUT-OTIB-0037, Rev. 00 PC-1, Oak Ridge Associated Universities, Oak Ridge, 

Tennessee, July 21, 2006. 

Johnson, P. G., 2004, Technical Basis Document for the Los Alamos National Laboratory – 

Occupational Medical Dose, ORAUT-TKBS-0010-3, Rev. 00, Oak Ridge Associated 

Universities, Oak Ridge, Tennessee, December 29, 2004. 

Kathren, R.L., 2003, Technical Information Bulletin: Dose Reconstruction from Occupational 

Related Diagnostic X-ray Procedures, ORAUT-OTIB-0006, Revision 02, Oak Ridge Associated 

Universities, Oak Ridge, Tennessee, December 29, 2003. 

Kathren, R L. and Shockley, V. E., 2005, Technical Information Bulletin: Dose Reconstruction 

from Occupationally Related Diagnostic X-ray Procedures, ORAUT-OTIB-0006, Rev. 03, Oak 

Ridge Associated Universities, Oak Ridge, Tennessee. December 21, 2005. 

Mantooth, D, 2006, Paducah Gaseous Diffusion Plant – Occupational Internal Dose, ORAUTTKBS-0019-5, Rev. 01, Oak Ridge Associated Universities, Oak Ridge, Tennessee, October 25, 

2006. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

67 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Mantooth, D. S., and Barton, C. B., 2007, Paducah Gaseous Diffusion Plant – Occupational 

Internal Dose, ORAUT-TKBS-0019-5, Rev. 01 PC-1, Oak Ridge Associated Universities, Oak 

Ridge, Tennessee, January 31, 2007. 

Medley, D.W., R.L. Kathren, and A.G. Miller, 1994, Diurnal Urinary Volume and Uranium 

Output in Uranium Workers and Unexposed Controls, Health Physics, volume 67, number 2, pp. 

122–133. 

ge Tennessee, January 19, 2005. 

Merwin, S. E., 2005, Use of Coworker Dosimetry Data for External Dose Assignment, ORAUTOTIB-0020, Rev. 01, Oak Ridge Associated Universities, Oak Ridge, Tennessee, October 7, 

2005. 

Merwin, S. E., External Coworker Dosimetry Data for the K-25 Site, 2006, ORAUT–OTIB ­

0026-6, Rev. 00 PC-2, Oak Ridge Associated Universities, Oak Ridge, Tennessee, November 15, 

2006. 

Miles, C. J. 2006, Technical Basis Document for the K-25 Site – Occupational External Dose, 

ORAUT-TKBS-0009-6, Rev. 00 PC-1, Oak Ridge Associated Universities, Oak Ridge, 

Tennessee, September 26, 2006. 

Murray, W. E., 2006, Technical Basis Document for the Y-12 National Security Complex – 

Occupational Medical Dose, ORAUT-TKBS-0014-3, Rev. 00 PC-3, Oak Ridge Associated 

Universities, Oak Ridge, Tennessee, April 18, 2006. 

NCRP 1989, (National Council on Radiation Protection and Measurements) 1989, Medical Xray, Electron Beam, and Gamma-Ray Protection for Energies Up to 50 MeV (Equipment Design, 

Performance, and Use), Report No. 102, NCRP, Bethesda, Maryland. 

NIOSH, 2005, Meeting with PACE Local 5-288 and International Union, NIOSH Dose
 

Reconstruction Meeting on K-25 Site, National Institute for Occupational Safety and Health, 

Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, 

Washington, DC, April 6, 2005, http://www.cdc.gov/niosh/ocas/pdfs/tbd/outreach/wo040605.pdf 

OCAS (Office of Compensation Analysis and Support) 2002, External Dose Reconstruction 

Implementation Guidelines, Revision 1, OCAS-IG-001, National Institute for Occupational 

Safety and Health, Centers for Disease Control and Prevention, U.S. Department of Health and 

Human Services, Washington, DC. 

ORAUT (Oak Ridge Associated Universities Team) 2004, Coworker Data Exposure Profile 

Development, ORAUT-PLAN-0014, Rev.00, Oak Ridge, Tennessee, November 24, 2004. 

Orr, M.P. and Demopoulos, P. 2006, Pinellas Plant – Site Description, ORAUT-TKBS-0029-2, 

Rev. 01, Oak Ridge Associated Universities, Oak Ridge, Tennessee, October 4, 2006. 

Pardue, L.A., N. Goldstein and E.O. Wollan, 1944, Photographic Film as a Pocket Radiation 

Dosimeter, CH-1553-A-2223, Metallurgical Laboratory, Chicago, Illinois. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

68 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Rich, B. L., 2004, Technical Basis Document for the Fernald Environmental Management 

Project (FEMP) – Occupational Internal Dose, ORAUT-TKBS-0017-5, Rev. 00, Oak Ridge 

Associated Universities, Oak Ridge, Tennessee, May 28, 2004. 

Rohrig, N. D, 2004, Technical Basis Document for the Idaho National Engineering and 

Environmental Laboratory (INEEL) – Occupational Medical Dose, ORAUT-TKBS-0007-3, 

Rev. 00, PC-1, Oak Ridge Associated Universities, Oak Ridge, Tennessee, May 28, 2004. 

Rohrig, N. D., and Bump, S. L., 2006, Idaho National Engineering and Environmental 

Laboratory – Occupational External Dosimetry, ORAUT-TKBS-0007-6, Rev. 01, Oak Ridge 

Associated Universities, Oak Ridge, Tennessee, November 7, 2006. 

Rollins, G., and Brackett, E. M., 2007, Technical Information Bulletin, Maximum Internal Dose 

Estimates for Certain DOE Complex Claims, ORAUT-OTIB-0002, Rev. 02, Oak Ridge 

Associated Universities, Oak Ridge, Tennessee, February 7, 2007. 

SC&A 2004, SC&A Standard Operating Procedure for Performing Site Profile Reviews, Rev. 0, 

March 18, 2004. 

Scalsky, E.D., 2005, Savannah River Site, ORAUT-TKBS-0003, Revision 3, Oak Ridge 

Associated Universities, Oak Ridge, Tennessee, April 5, 2005. 

Schultz, N. B., 1966, Inhalation Cases of Enriched Insoluble Uranium Oxides, Report K-C-822, 

Union Carbide Corporation, Nuclear Division, Oak Ridge Gaseous Diffusion Plant, Oak Ridge, 

Tennessee, August 16, 1966. 

Shockley, V. E., and Kathren, R. L., 2005, Hanford Site – Occupational Medical Dose, ORAUTTKBS-0006-3, Rev. 01, Oak Ridge Associated Universities, Oak Ridge, Tennessee, April 11, 

2005). 

Smith, R. F., 1984, Historical Impact of Reactor Tails on the Paducah Cascade, KY/L-1239, 

Union Carbide Corporation, Paducah, Kentucky. 

Szalinski, P. A., 2006a, K-25 Site – Introduction, ORAUT-TKBS-0009-1, Rev. 01, Oak Ridge 

Associated Universities, Oak Ridge, Tennessee, May 4, 2006. 

Szalinski, P. A., 2006b, K-25 Site – Site Description, ORAUT-TKBS-0009-2, Rev. 01, Oak 

Ridge Associated Universities, Oak Ridge, Tennessee, October 4, 2006. 

Thomas, B. R., 2006, K-25 Gaseous Diffusion Plant – Occupational Internal Dose, ORAUTTKBS-0009-5, Rev. 00 PC-1, Oak Ridge Associated Universities, Oak Ridge, Tennessee, 

October 4, 2006. 

Tuck R. L. 1957, Survey of the Picker R-2 X-ray machine, ORNL Health Physics Group, Oak 

Ridge National Laboratory, Oak Ridge, Tennessee, August 21, 1958. 

Turner, J. E., 2004 Technical Basis Document for the K-25 Site – Occupational Medical Dose, 

ORAUT-TKBS-0009-3, Rev. 00, Oak Ridge Associated Universities, Oak Ridge, Tennessee, 

June 29, 2004. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

69 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Turner, J. E., 2006 Technical Basis Document for the K-25 Site – Occupational Medical Dose, 

ORAUT-TKBS-0009-3, Rev. 00 PC-1, Oak Ridge Associated Universities, Oak Ridge, 

Tennessee, November 7, 2006. 

Turpin, B. 2006, Paducah Gaseous Diffusion Plant – Site Description, ORAUT-TKBS-0019-2, 

Rev. 00, Oak Ridge Associated Universities, Oak Ridge, Tennessee, August 21, 2006. 

Watson, Jr., J.E., J.L. Wood, W.G. Tankersley, and C.M. West, 1994. Estimation of Radiation 

Doses for Workers without Monitoring Data for Retrospective Epidemiologic Studies, Health 

Phys. 64(4):402-205. 

Westbrook, J. L., 2005, Basis for the Development of an Exposure Matrix for the Mallinckrodt 

Chemical Company, St. Louis Downtown Site and the St. Louis Airport Site, St. Louis, Missouri, 

Period of Operation; 1942-1958, ORAUT-TKBS-0005, Rev. 01, Oak Ridge Associated 

Universities, Oak Ridge, Tennessee, March 10, 2005. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

70 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

ATTACHMENT 1: NIOSH TECHNICAL DOCUMENTS CONSIDERED 

DURING THE REVIEW PROCESS 

TECHNICAL BASIS DOCUMENTS 

ORAUT-TKBS-0009-1, K-25 – Introduction, Rev. 01 (Szalinski 2006a). May 4, 2006. 

ORAUT-TKBS-0009-2, Technical Basis Document for the K-25 Site – Site Description, Rev. 01 

(Szalinski 2006b). October 4, 2006. 

ORAUT-TKBS-0009-3, Technical Basis Document for the K-25 Site – Occupational Medical 

Dose, Rev. 00 PC-1 (Turner 2006). November 7, 2006. 

ORAUT-TKBS-0009-4, Technical Basis Document for the K-25 Site – Occupational 

Environmental Dose, Rev. 00 PC-1 (East 2006). September 26, 2006. 

ORAUT-TKBS-0009-5, K-25 Gaseous Diffusion Plant – Occupational Internal Dose, Rev. 00 

PC-1 (Thomas 2006). October 4, 2006. 

ORAUT-TKBS-0009-6, Technical Basis Document for the K-25 Site – Occupational External 

Dosimetry Rev. 00 PC-1 (Miles 2006). September 26, 2006. 

TECHNICAL SUPPORT DOCUMENTS 

ORAUT-OTIB-0002, Rev. 02, (2007), Technical Information Bulletin, Maximum Internal Dose 

Estimates for Certain DOE Complex Claims, Oak Ridge Associated Universities, Oak Ridge, 

Tennessee, February 7, 2007, (Rollins and Brackett 2007). 

ORAUT-OTIB-0006, Technical Information Bulletin – Dose Reconstruction from 

Occupationally Related Diagnostic X-ray Procedures, Rev. 03 (Kathren and Shockley 2005). 

Oak Ridge Associated Universities, Oak Ridge, Tennessee. December 21, 2005. 

ORAUT-OTIB-0018, Rev. 01, (2005), Technical Information Bulletin – Internal Dose 

Overestimates for Facilities with Air Sampling Programs (Brackett & Bihl 2005). Oak Ridge 

Associated Universities, Oak Ridge, Tennessee. August 9, 2005. 

ORAUT-OTIB-0020, Rev. 01, (2005) Use of Coworker Dosimetry Data for External Dose 

Assignment, (Merwin 2005b), Oak Ridge Associated Universities, Oak Ridge, Tennessee. 

October 07, 2005. 

ORAUT-OTIB-0026, External Coworker Dosimetry Data for the K-25 Site, Rev. 00 PC-2 

(Merwin 2006). Oak Ridge Associated Universities, Oak Ridge, Tennessee, November 15, 2006. 

ORAUT-OTIB-0035, Internal Dosimetry Coworker Data for the K-25 Site Rev. 00 PC-1 (Cherry 

2006). Oak Ridge Associated Universities, Oak Ridge, Tennessee, July 21, 2006. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

71 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

ORAUT-OTIB-0052, Rev. 00 PC-1, Parameters to Consider when processing Claims for 

Construction Trade Workers, (Chew et al., 2007). Oak Ridge Associated Universities, Oak 

Ridge, Tennessee, January 16, 2007. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

72 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

ATTACHMENT 2: SITE EXPERT INTERVIEW SUMMARY 

The purpose of the Site Expert Interviews was to receive first-hand accounts of past radiological 

control and personnel monitoring practices at the Oak Ridge K-25 Gaseous Diffusion Plant, and 

a better understanding of how operations were conducted. A total of 41 current or retired 

workers were interviewed. An attempt was made with the retirees to interview previous workers 

who had been employed at this facility for at least 20 years. Approximately three-quarters of the 

interviewees are currently employed at K-25, with the remaining one-quarter being retirees. 

Harry Pettengill, Abe Zeitoun, Kathy Robertson-DeMers, and R. Thomas Bell, who are all 

employees of SC&A, conducted the interviews. These interviews were held from December 11– 

15, 2006, and were conducted at the East Tennessee Technology Park (ETTP), Local UVW 

Union Hall, or at the DOE Federal Building in Oak Ridge, Tennessee. 

These interviews were held in addition to open discussions with K-25 workers conducted by 

NIOSH and Oak Ridge Associated Universities (ORAU) on April 5, 2005, with the Security 

Police and Fire Professionals of America and the International Guards of America; and on April 

6, 2005, with the Pace Local 5-288 and International Union. A more in-depth interview process 

with the K-25 Site workers is considered by SC&A to be helpful in better understanding the 

working environment and radiological conditions that occurred at the K-25 Site over its many 

years of operation. 

Interviewees were selected so as to represent a reasonable cross-section of the various job 

disciplines that were characteristic of those who are currently working or who had worked at the 

K-25 Site. Time was also spent reviewing unclassified health physics records and reports, 

conversing with records staff, and reviewing documents at the DOE Reading Room, Oak Ridge, 

Tennessee, and the Bechtel Jacobs Library at Building K-1007. 

Workers were briefed on the purpose of the interviews, and background on the EEOICPA dose 

reconstruction program and site profiles, and asked to provide their names, in case there were 

follow-up questions. Participants were advised that participation was strictly voluntary. Each 

participant was given the opportunity to review this interview summary for accuracy and 

completeness. This is an important safeguard against missing key issues or misinterpreting some 

vital piece of information. 

When these K-25 Site Expert interviewees were asked about their review of the Oak Ridge 

Associated Universities (ORAU) Site Profile TBDs, they indicated that they felt that the ORAU 

K-25 TBDs seem accurate and complete, and that they effectively incorporated the concerns of 

the K-25 workers. Most all facilities seemed to be covered. The interviewees were not aware of 

any additional sources of information relating to historical and potential exposure situations. A 

few of the interviewees had not looked at Table 2-2, and were unaware of any additional 

buildings at K-25 that were not covered in the K-25 Site Description TBD. Another interviewee 

indicated that he had been interviewed by NIOSH/ORAU. Others in the group had attended one 

of the NIOSH /ORAU outreach meetings. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

73 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

The Dosimetry staff was interviewed by NIOSH/ORAU during the preparation of the site profile. 

They were not given the chance to comment on the site profile once it was drafted. There have 

been some difficulties with employment verification. 

One interviewee indicated that he was not involved in the development of the K-25 TBDs, that 

the SC&A interviews were the first such interviews for him, and that NIOSH/ORAU had not 

interviewed him. He was not involved in the NIOSH/ORAU worker outreach meetings. The 

interviewee did participate in the worker medical program and answered the questionnaire the 

Medical Department asked him to fill out. 

It was one RCTs opinion that for claims in the 1940s, 1950s, and 1960s, NIOSH does not really 

know where workers worked. The K-25 RadCon staff is concerned about the exclusion of 

former K-25 workers from the development of the site profile. The conflict of interest policy 

does not make sense. Two interviewees indicated that they were not interviewed as a part of the 

site profile development. Two interviewees stated that some information provided during 

worker outreach meetings was considered by NIOSH/ORAU in development of their K-25 

TBDs. One interviewee indicated that the coworker doses established in the NIOSH/ORAU site 

profiles look about right. It was pointed out that 5 to 50 projects at K-25 have been granted 

Special Exposure Cohort (SEC) status. Most of these involved the thermal diffusion process. 

One of the interviewees did not see this in operation. 

All interviews have been documented and summarized below. The information provided is not a 

verbatim discussion, but a summary of information from multiple interviews with multiple 

individuals. Individuals have provided this information based on their personal experience. It is 

recognized that these current and former workers’ recollections and statements may need to be 

further substantiated before adoption into the six Oak Ridge K-25 Gaseous Diffusion Plant 

TBDs; however, they stand as critical operational feedback. These interview notes are provided 

in that context; former worker input is similarly reflected in our discussion and, with the 

preceding qualifications in mind, has contributed to our findings and secondary issues. 

The interviewees represented a wide array of job categories and responsibilities. In addition, this 

cross-section of personnel worked in many of the facilities/areas represented in the Site 

Description TBD. It should be noted that many of the interviewees stated that many 

facilities/area were not listed in Table 2-2 of the Site Description TBD. The following is a list of 

job categories represented during the interviews, and a table listing the facilities/areas listed in 

the TBD, along with additional facilities/areas that these interviewees identified as missing from 

this document. A comment section has also been added to this table that shows which buildings 

were missing in Table 2-2 of the Site Description TBD, and interviewee information provided 

about the buildings during their interviews. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

74 of 191 

 

The job categories represented by the interviewees included the following: 

Administrative Assistant 

Analytical Chemistry 

Analytical Chemistry 

Building Demolition 

Cable Spicer/Lineman 

Chemist 

Commander 

Community Advocacy 

Coordinator 

Craft Supervisor 

D&D worker 

Dosimetry Manager 

Electrician 

Engineer 

Engineering Manager 

Engineering Specialist 

Environmental and Waste Management 

Environmental Engineer 

ES&H Administrator 

ES&H Representative 

Facility Manager 

Field Services 

Fire Protection 

Health Physicist 

Industrial Hygienist 

Internal Dosimetrist 

K-25 Gaseous Diffusion Plant Worker 

Machinist 

Maintenance 

Maintenance Engineer 

Maintenance Mechanic 

Medical X-ray Technologist 

Operator 

Painter 

Physician 

Pollution Prevention Project Manager 

Project Engineer 

Quality Assurance Specialist 

RadCon Field Operations Manager 

RadCon Subcontractor Project Manager 

Radiation Control Technician (RCT) 

Radiological Engineer 

RCT Supervisor 

Records Manager 

Security 

Security Inspector 

Security Police Officer 

Shift Superintendent 

Shift Supervisor 

Site Dosimetry Coordinator 

Store Clerk 

Supervisor 

Supervisor I 

Supervisor II 

System Engineer 

Union Safety and Health Representative 

Utilities Worker 

Waste Characterization 

Table of Building Information 

Building No. Comments About the Building 

G-Pit Missing in Table 2-2, K-25 Site Description TBD. 

K-25 Primarily UF6, but pervasive secondary radioisotopes were throughout (Tc-99, Am-241, Pu-240, 

Np-239, and thorium). 

There was no robust Radiological Control Program until about 1989. A ChemRisk Report of 

March 2000 concluded that airborne uranium releases were 50% higher than values reported by 

DOE. Tc-99 was present. Beryllium was stored in K-25 in the early days. There was HEU in 

this building and it had to be constantly cleaned up. Fires occurred in K-25. 

K-27 Tc-99 was present. 

K-31 Tc-99 was present. There was a fire in the K-31 ventilation ducts in the 1972–1973 timeframe. 

The oil in these ducts was PCB-contaminated. 

K-33 Seals were often blown when they were trying to see how much pressure the seals could hold. 

K-101 Missing in Table 2-2, K-25 Site Description TBD. Some incineration was done in the building 

in the early days. 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker
 

Health for factual accuracy or applicability within the requirements of 42 CFR 82.
 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

75 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 
 

Health for factual accuracy or applicability within the requirements of 42 CFR 82.
 

 

 

 

 

Table of Building Information 

Building No. Comments About the Building 

K-131 Maintenance. This building was a process auxiliary. Contamination problems were common. 

Some incineration was done in the building in the early days. Missing in Table 2-2, K-25 Site 

Description TBD. 

K-200 

K-310-3 Purge Cascades. Tc-99 was not significant. 

K-311-1 Purge Cascades. Tc-99 was not significant. 

K-315 Fires occurred in this building. One worker cut the wrong pipe and the resulting fire created a 

glowing chuck of metal. 

K-402-8 Purge Cascades. Tc-99 was not significant. 

K-402-9 Purge Cascades. Tc-99 was not significant. 

K-413 Missing in Table 2-2, K-25 Site Description TBD. 

K-601 Tailings withdrawal. Some incineration was done in the building in the early days. Missing in 

Table 2-2, K-25 Site Description TBD. 

K-622 

K-631 Missing in Table 2-2, K-25 Site Description TBD. 

K-632 Missing in Table 2-2, K-25 Site Description TBD. 

K-633 Test Loops. Contamination problems were common. This building was also a process 

auxiliary. Missing in Table 2-2, K-25 Site Description TBD. External doses as high as 1.5 R/hr 

were seen in this building. 

K-701 This building had a beryllium problem. A beryllium prevention program was started in 1995– 

1996. 

K-770 Scrap Yard with Converter Heads and Casks that were radioactively contaminated. Missing in 

Table 2-2, K-25 Site Description TBD. 

K-1001 

K-1004-A Analytical Laboratory 

K-1004-B Analytical Laboratory 

K-1004-C Analytical Laboratory 

K-1004-D Analytical Laboratory 

K-1004J 

K-1004L 

K-1006 

K-1007 Administrative, Medical, and Active Records Vault 

K-1008C 

K-1008D Decontamination Facility. 

K-1010 Cylinders were present in this building. 

K-1015 Laundry Facility. 

K-1024 Radium was common. This facility had radioactive maintenance activities. Radioactive 

contamination was common. 

K-1030 Radium was common. This facility had radioactive maintenance activities. Radioactive 

contamination was common. 

K-1034A Inactive records vault. Field radiological control records were stored here until older records 

were shipped to the Federal Records Center in Atlanta. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

76 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 
 

Health for factual accuracy or applicability within the requirements of 42 CFR 82.
 

 

 

 

 

 

 

 

 

 

 

 

Table of Building Information 

Building No. Comments About the Building 

K-1035 Radium was common. This facility had radioactive maintenance activities. Radioactive 

contamination was common. 

K-1037 Atomic Vapor Laser Isotope Separation (AVLIS) Building. There was a dumpster fire in this 

building. Uranium oxidized and caught fire in the dumpster. Also known as the Barrier Plant 

and had blend towers. 

K-1037C Smelting was done in this building. 

K-1041 Laboratory where testing of instrument systems that were used in the cascades was done. 

Contaminated equipment was often brought in for cleaning or repairs, which lead to the 

contamination of building surfaces and equipment. Groundwater contamination was detected 

under the basement. This was an R&D area in the north end of the building that was off limits 

to most personnel. Contamination was common. 

K-1064 The Peninsula. 

K-1065 Waste Storage Facility. Missing in Table 2-2, K-25 Site Description TBD. 

K-1066 Cylinder Storage Yards. 

K-1070 Commonly used to describe a series of six burial grounds for contaminated waste. These burial 

grounds potentially contain thorium, uranium, and technetium. Missing in Table 2-2, K-25 Site 

Description TBD. 

K-1074 Cascades were operating in this building, and there was a lot of hydrogen fluoride and uranium. 

K-1121 A lot of contamination was found when this building was torn down. 

K-1131 Feed Building. The operations in the building involved the conversion of Ug4 to UF6 through 

an ash-oxide fluorination system. Venting loss of 58,854 grams of uranium and 407 grams of 

U-235. Work from K-1421 was completed here. One interviewee read that workers manually 

shoveled ash into hoppers in the early 1950s. This building had a blend tower, screw 

conveyors, and a horizontal reactor. A lot of contamination was found when this building was 

torn down. 

K-1133 Missing in Table 2-2, K-25 Site Description TBD. 

K-1200 Hot runs were done here that resulted in some hot stream releases. 

K-1210 Hot runs were done here that resulted in some hot stream releases. Many cylinders were lying 

there. 

K-1210A 

K-1203 Radioactive sewage sludge was done in this building. 

K-1220 Hot runs were done here that resulted in some hot stream releases. 

K-1225 

K-1231 Waste was put into a tanker and shipped to K-25 for waste treatment. Missing in Table 2-2, 

K-25 Site Description TBD. 

K-1233 Missing in Table 2-2, K-25 Site Description TBD. 

K-1300 A complex of buildings. K-1300 had stacks. Missing in Table 2-2, K-25 Site Description TBD. 

Some of these buildings were involved in uranium recovery. 

K-1301 Fluoride Production Facility and also the Nitrogen Plant. There was a large area painted with 

magenta paint and signs are posted that read “Do Not Disturb.” Missing in Table 2-2, K-25 Site 

Description TBD. Involved in uranium recovery. 

K-1302 On May 26, 2006, 20.5 pounds of scaling containing 34.8% uranium were removed from the 

walls and bottom of the K-1302 vent stack. 

K-1310B Offices. 

K-1310LM 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

77 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 
 

Health for factual accuracy or applicability within the requirements of 42 CFR 82.
 

 

 

 

 

 

 

 

Table of Building Information 

Building No. Comments About the Building 

K-1401 Machine Shop. Materials went from this building to the decontamination labs in K-1401 or 

K-1420. Oxidants were used to remove the plugs from the barriers and the oxidants became 

contaminated. Contamination problems were present. The ventilation ductwork was 

contaminated in this building. Gaseous diffusion done in this building. Process compressors 

alloyed with beryllium, during tipping operations on the compressor blades, spread machining 

dust containing beryllium throughout the building. Missing in Table 2-2, K-25 Site Description 

TBD. 

K-1405 Missing in Table 2-2, K-25 Site Description TBD. 

K-1407 Laboratory. This building was a Pit radioactive acids neutralization area. Missing in Table 2-2, 

K-25 Site Description TBD. 

K-1413 Radium was common. This building was used for experiments in the early phases of the 

uranium gaseous diffusion process development. One interviewee described the building as a 

“bad lab.” Missing in Table 2-2, K-25 Site Description TBD. In K-1413, they did radioactive 

material experiments, and the building served as one of the development labs. 

K-1417 Raffinate Ponds. 

K-1420 Decontamination Facility. This building was the most contaminated place on the K-25 Site. 

This building housed the pickling operations, acid baths, and a decontamination facility, and 

was the building where operations of various types were carried out. Attempts were made in 

this building to recover uranium. K-1420 had showers that were regularly used. Hand 

contamination was common, and most workers didn’t even know they were contaminated. 

There was no monitoring in the early days. The floor was painted a lot to fix contamination 

spread. The break room was found to be contaminated at one time. They used blowguns to 

blow off the paint used to cover contaminated floors, and the chunks went all over the place. 

This was around the 1975 timeframe. K-1420 sludge ponds had to be cleaned out by dredging 

dirt and sludge out of them. K-1420 had a flame tower. 

K-1421 Incinerator Building. This building had the original furnaces, which were like brick oven 

fireplaces with stacks. Smelting was done in this building. This building had few RadCon 

controls in the early years and anything that could burn was incinerated there. In the northwest 

corner of this building, they burned contaminated clothing in the incinerator. This area often 

had a lot of radiological hot spots. The incinerator in K-1421 had few controls in the early days 

and anything that could burn was incinerated there. 

K-1423 A release of yellow cake leaked on the floor in this building. 

K-1435 TSCA Incinerator. 

K-1580 Offices. 

K-1600 Series of Buildings, all bearing 1600 numbers. Missing in Table 2-2, K-25 Site Description 

TBD. 

K-2527 

K-3133 

K-Shop 

L-Lab This was a hot area around 1984 according to one interviewee painter. 

Chin Building 

Commerce Park 

ETTP Site East Tennessee Technology Park. Recent name for the old K-25 Site. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

78 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

This Site Expert Interview Summary has been divided into the following sections: 

• Production/Operations 

• Work for Others 

• Transfer between Facilities 

• Radiological Control (RadCon) and Health Physics Aspects 

• Radiation Monitoring 

• Internal Dosimetry 

• External Dosimetry 

• Potential Missed Dose 

• Contamination 

• Decontamination and Decommissioning 

• Waste Disposal 

• Incidents/Unusual Occurrences 

• Audits 

• Environmental Dose and Monitoring 

• Industrial Hygiene/Chemical Exposures 

• Maintenance/Crafts/Utilities 

• Dosimetry Records 

• Medical Examinations 

• Medical X-ray Procedures 

• Union and Safety Concerns 

• Security 

• Safety Hazards 

• References Provided or Cited by Interviewees 

PRODUCTION/OPERATIONS 

Worker health and safety at K-25 was overshadowed by production. The culture that was 

maintained at the site was to impede information about risks and hazards from reaching the 

employees under the umbrella of protecting technical secrets. This statement was similar to a 

quotation in the DOE’s Office of Oversight 2000 report, Independent Investigation of the East 

Tennessee Technology Park, Volume 1: Past Environment, Safety, and Health Practices, which 

the interviewees provided. 

Workers were exposed to a variety of radionuclides, but mainly uranium compounds, uranium 

decay products, transuranics, and fission products, including technetium. Supervisors at the 

plant were aware that workers were receiving internal doses from their work environment. 

Workers left the complex with uranium dust on their clothes and shoes. Protective equipment 

provided to workers was inadequate. Frequent airborne contamination problems were common 

while doing cell change-outs and maintenance. Assigning respirator use for workers evolved 

from multi-user, to single user, to single use. In the early years, workers would reuse their 

respirators and carry them around their necks. Some maintenance workers stored their 

respirators in the bottom of their toolboxes, where many rotted from lack of use and exposure to 

heat. Respirators were stored in cabinets, and there was intermittent cleaning of respirators 

between uses. Respirators were in use when one interviewee reported to K-25 in 1975. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

79 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Types of radioactive material at K-25 included primarily UF6, but also large amounts of UF4 in 

the early days. UO2F2 was the primary waste form. There are pervasive secondary 

radionuclides throughout (Tc-99, Am-241, Pu-240, Np-237, and thorium) as minor constituents 

to the U. The labs worked with much more, which included fission products of many types. The 

physical form is gas (primarily), solid (in cylinders), or liquid (in autoclaves). Other forms were 

mainly solids (in fluoride or oxide forms). In 1976, working on seals was a radiological hazard, 

since it was known that Tc-99 was a contaminant of these operations. HP knew how much 

radiation was coming off the above radionuclides, as well as some of the fission products. HP 

moved toward experiments to learn more about what was present. In the early days, it was hard 

to detect some of these radionuclides with the survey instruments they had. 

There were small-scale operations conducted by ORNL in the Powerhouse area. K-25 provided 

support services to these operations. 

In regards to operations with uranium that required heating to high temperatures, one 

interviewee responded by saying that he didn’t know for sure. There were oxide conversion 

facilities in K-1420 and maybe K-101, K-601, and K-131. 

During this time, the functions of HP and protection and medical programs were ancillary and 

poorly funded. Health and Safety oversight was a function of line management, who lacked 

training and the incentive to be effective. The emphasis was always on production. 

In the early days, major leaks were done by qualified welders, but these workers had poor 

training. General Wesley Groves, the project manager, wanted the building built in 69 days, and 

it was hard to ensure that the welds were done properly. As a result, there were many leaks— 

some huge leaks. There were thousands of pounds of U-235 brought in. The operational time 

for the three early plants was short. The push to increase production contributed to the building 

of Y-12. 

It was reported that the Army Corps of Engineers captured draftees out of the Universities and 

brought them to Oak Ridge to help build the K-25 gaseous diffusion plants. 

K-1401 was the Maintenance Shop. Materials went from there to the decontamination labs in 

K-1401 or K-1420. The basement of K-1420 had a different purpose and had conditioning 

stands. The purpose of the basement area was to convert plugs (using primary separation 

devices). Oxidants were introduced to remove the plugs from the barriers. During the process, 

the oxidants became contaminated with uranium. These oxidized contaminants were evacuated 

through stacks to the atmosphere outside the plant. In K-1420, attempts were made to recover as 

much of the uranium as was possible. In the early days, little was done in the way of radioactive 

waste management. There were only one or two health physicists (HPs) in those early days. 

In 1959, they shut down the old electrical plant. In the 1960s, they sold the generators, stripped 

them out, and hauled them out by rail. Another power plant was built to replace the old electrical 

plant. The power plant provided the steam to create the electricity needed. It was most difficult 

to tear down. In the 1990s, they demolished the power plant. There are now five power sources 

into the site. The coal dust from these power generation stations is a good source of radium that 

sometimes is carried by the wind to the K-25 Site. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

80 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

In 1972, production was emphasized over safety. Meeting production schedules was paramount. 

In those days, K-25 management was immune to audits, and there appeared to be no radiological 

concerns. For instance, they were allowed to eat and drink in the production area of the labs, and 

then this was no longer allowed; regulations tightened up in the late 1980s. Also in the late 

1980s, Union Carbide began setting up separate lunchrooms away from the production areas. 

Health Physics coverage and overview improved throughout the 1980s. 

The responsibilities of the Field Services Department were mainly uranium recovery, which was 

recycled from solutions generated in K-1420. Monitoring for exposure to radionuclides and 

external exposure was very scant in the 1970s and early 1980s. In 1983, the Resource 

Conservation and Recovery Act (RCRA) began to have an impact on how K-25 handled their 

radiological waste. They did not do waste processing for other facilities at Oak Ridge or outside. 

Rad Safety’s major problems had to do with decontamination until the late 1980s. It was not 

until the late 1980s that the Toxic Substances Control Act (TSCA), the National Emission 

Standards for Hazardous Pollutants (NESHAPs), and Department of Energy (DOE) regulation 

changes purged a lot of the old timers and brought in an increased staff of health physics 

personnel that ushered in more stringent radiological control programs. This also coincided with 

the shutdown of production. 

Uranium was more valuable than gold, thus the workers at the K-25 Site attempted to recover as 

much of the uranium from the enrichment waste products as they could. Materials were taken 

out of the process building, decontaminated, and extracted principally by a wet process. Liquid 

was discharged in low concentrations for recovery. A liquid-liquid extraction process was used 

to convert uranium to UO2. As a part of this, the material was heated in a calciner at 

temperatures as high as 1,300oF to 1,500oF. The uranium fluoride was oxidized to make UF6. It 

was a U3O8 conversion that was done in Building K-1420. They took uranium out of trapping 

systems, oils, paper, plastic, and woods by a leaching out process. Building 1421 had the 

original furnaces, which were like brick oven fireplaces with stacks. By simple gas combustion, 

impurities were burned off. This facility was shut down in the late 1980s, because the TSCA 

incinerator was being put into operation. 

Operations with uranium at K-25 that required heating of oxides to high temperatures involved 

work in the calciner where U3O8 was produced, and later where UF4 was converted to UF6. This 

latter process involved the highest temperatures. 

The principal radioactive materials found at K-25 are uranium, plutonium, neptunium, and 

Tc-99. There was no field characterization at K-25. K-25’s principal role was to handle, 

process, and store both enriched and depleted uranium. 

Some smelting was done in both K-1420 and K-1037C. The process was used to recover 

aluminum and nickel. Personnel manually removed ash from the smelter. Personnel protective 

clothing was worn during this job. Most of the material that needed smelting went to Paducah. 

Building K-1131 was involved in the conversion of UF4 to UF6 through an ash-oxide fluorination 

system. Ash was put into hoppers. Respiratory protection was worn at the drumming station. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

81 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

In 1975, the staff at K-25 totaled about 4,000–5,000. By 1978, the staff peaked at 6,000–6,500. 

Production in the gaseous diffusion plant was stopped in 1985. They worked hard to meet the 

growing need for enriched uranium, and conducted uranium recoveries to assist in adding to the 

uranium on hand. The production phase of uranium enrichment at the original K-25 gaseous 

diffusion occurred from 1953–1965. Production at the other facilities (i.e., K-31/K-33) 

continued until 1984. The whole plant site is sometimes referred as K-25, similar to ORNL 

being called X-10. One interviewee indicated that overtime was not common at K-25. 

There was little HP coverage until mid-to-late 1980s. It was about that time that they started 

using friskers in K-25 and K-27, and set up better radiation control procedures. The number of 

safety employees gradually increased until 1989, when the HP staff was greatly increased. For 

this interviewee, little transfer occurred between facilities and he did not have much 

communication with Y-12 or X-10. 

In 1980, the HP and IH groups were in Technical Services. Earlier on, they were under the 

Medical Department. IH did surveys but they were not radiological in nature. The two groups 

did not work much with each other. 

The Chemical Operations Group evolved into the TSCA Incinerator Group. All waste that could 

be burned went to the incinerators. The second generation TSCA Incinerator had a sophisticated 

offgas process. So as not to jeopardize the permitting process, all other incinerators on the K-25 

Site were shut down. The average assay at the facility at the time was 1.5% of the authorized 

limits. 

The TSCA Incinerator management, testing, and permitting had been conducted by one of the 

interviewees up until the time of almost the last permitting process, when that function was 

assigned to another office. The final permitting of the new TSCA Incinerator took place around 

the 1989–1990 timeframe. An incident happened that brought close scrutiny on the whole 

permitting process. The predecessor to the first Tiger Teams also got involved. The TSCA 

Incinerator was designed to burn TSCA and RCRA regulated solids, liquids (organic liquids), 

and mixed waste. All these contaminants had some radiological constituents. The TSCA 

Incinerator was not for burning oils. K-25 had thousands upon thousands of gallons of PCBs 

(polychlorinated biphenyls). The TSCA regulations said the Incinerator had to operate below 

2,200o

F and the RCRA regulations said it had to operate below 1,900oF. So it took some time to 

work this out. The TSCA Incinerator has been, and still is, periodically tested and re-permitted. 

Production had already been shut down when the TSCA Incinerator came up to operation. 

Through the 1990s, the decontamination organizations continued their decontamination 

processes at K-25. The TSCA incinerator had an off gas treatment system. 

It was mentioned that the Portsmouth Gaseous Diffusion Plant had a larger and better HP staff, 

especially their airborne monitoring program. The programs at K-25, however, were similar. 

Paducah dealt more with fission products, but the work was about the same. K-25 seemed to 

have more problems than the other gaseous diffusion plants. There were a lot more facilities and 

a lot more contaminated facilities. K-25 had a high change-out of low activity projects. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

82 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

ORNL, Y-12, and K-25 management would bid on jobs in the 1980s, and as a result of who got 

the funding, personnel would be laid off at one site and take a job at another site. This was 

during the era of Lockheed Martin and Martin Marietta. This was very common in those days. 

Some of the interviewees indicated that they transferred between K-25 and other Oak Ridge sites 

(e.g., Y-12 and X-10). One interviewee went to Y-12 frequently. 

Operations personnel worked areas K-31/33, K-29 Area, Utilities, etc. Maintenance personnel 

worked in the same areas and K-1420 or K-1401. Many maintenance personnel worked many 

buildings and were reassigned several times. Some crews worked the entire plant. 

Building K-1041, which was constructed in the early 1940s, contained a laboratory where testing 

of instrumentation systems used in the cascades took place. Contaminated equipment was often 

brought in for cleaning or repairs, which led to the contamination of building surfaces and 

equipment. Groundwater contamination was detected under the basement of K-1041. A copy of 

a draft report BJC/OR-1384 dated 2004 (Tetra Tech Inc. 2004) was provided that detailed the 

extent of contamination at Building K-1041. This report, however, was not part of the K-25 Site 

records database. 

DOE personnel rarely visited the K-25 Site facilities prior to the 1990s. 

It appears that NIOSH based their listing of facilities on the 1993 Consort Technologies 

document (K/HS-570). It appears all they know is what they read in that document. In general, 

though, the Site Description TBD has done a good job of listing major facilities. 

The following buildings were missing in the K-25 Site Description TBD (Szalinski 2006) and 

represent work areas of potential missed dose: 

• K-101 

• K-131 

• K-413 

• K-631 

• K-632 

• K-633 (Test Lab) 

• K-1133 

• K-1231 

• K-1233 

• K-1231 

• The 1300 complex (K-1300 – stacks, K-1301 – fluoride production, K-1301) 

• K-1405 

• K-1407 (Laboratory) 

• K-1413 

• The Centrifuge Complex (i.e., K-1200, K-1210 and K-1220) 

• The 1600 buildings 

• The 1070 series burial grounds 

• G-pit 

• K-1065 (Waste Storage Facility) 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

83 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

• K-770 (scrap yard with converter heads and casks) 

• K-601 (tailings withdrawal) 

Some of these facilities were involved in uranium recovery in all these buildings. In K-1423 and 

K-633 (Test Loop), external dose exposure got as high as 1.5 R/hr. The burial grounds 

potentially contain thorium, uranium, and technetium. 

K-1131 contained the blend towers, the screw conveyors, and had a horizontal reactor. In 1954, 

it was gutted out and all the equipment was upgraded. Reactor vessels came in during the 1970s.
 

K-1413 was used for experiments in the early phases of the uranium gaseous diffusion process 

development. Two of the workers at the time both knew about these experiments. 

Buildings K-1004-A, K-1004-B, K-1004-C, and K-1004-D were the analytical laboratories. 

WORK FOR OTHERS 

There were inter-assignments between facilities at the K-25 Site and between K-25 and Y-12 or 

X-10. Also, work was done for other DOE facilities, e.g., Los Alamos, Sandia National 

Laboratory, Portsmouth and Paducah Gaseous Diffusion Plants and others. 

K-25 implemented and participated in a program referred to as “Work for Others.” Other sites or 

organizations sent work to K-25 because of their unique capabilities (e.g., precision machining). 

This program included work for other DOE complex facilities, the National Aeronautics and 

Space Administration (NASA), and the DOD. Y-12 provided the decontamination services in 

the early days. 

The Work for Others program at K-25 didn’t start until about 1985. Y-12 conducted Power 

Operations on the K-25 Site starting in 1998. Laboratories on the K-25 Site processed 

radioactive material from Hanford. Uranium gas was introduced to the AVLIS system. There 

were office areas within the production facilities. USEC conducted research for the new 

centrifuge prototype in Building 1600 on the K-25 Site. It was noted that there was work for 

others in the 1960s, in the 1980s, and in the 1990s. Most of it was fabrication or engineering of 

things. It was also mentioned that K-25 did do a little bit of work for other countries. 

Also, the site could bid out plant services to other entities, such as the Navy, Air Force, and other 

DOE complex sites. K-25 was involved in the Aircraft Nuclear Propulsion (ANP) activities 

conducted by DOE. 

In 1982, DOE mandated that K-25 meet the requirements of RCRA. A local judge required the 

K-25 Site to treat approximately a million gallons of liquid radioactive waste. This waste was 

predominantly from the barrier production process. In addition, Y-12 was to discontinue 

discharging material to the S-3 Ponds. As a result, the waste was put into a tanker and shipped to 

K-25 for waste treatment. A lot of this work was done in Building 1231. Operators provided the 

liquid waste that was to go into the burners. Types of liquid waste included mop water, organic 

contaminants with uranium contamination, and cleaning solutions. Y-12 waste was burned. If 

this had not been handled effectively, the Judge’s ruling could have shut down Y-12. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

84 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

The uranium recovery process involved uranyl nitrate. Contaminants were released into the air. 

Air monitoring was done periodically on the incinerator in 1986–1987. They developed a Work 

for Others program group onsite that was dedicated to stack monitoring. The first real-time test 

of the stack monitoring system was when they purged the cascades in the late 1980s. The TSCA 

regulations required that continuous sampling and analysis be done in compliance with 

NESHAP. 

Another Work for Others project involved the National Pollutant Discharge Elimination System 

(NPDES) permits and work for other DOE laboratories. K-25 provided a place to store waste. It 

had a sophisticated machine shop. K-25 also had a nickel-plating capability that permitted the 

nickel-plating process to pull the nickel out of other materials and reclaim it. 

K-25 had the capability to perform a series on neutralization precipitations that was used on 

sludge being stored for disposal. The waste processing capability did not involve the recovery of 

uranium. 

In K-1420, K-25 supported other sites as “Work for Others.” They worked with the Savannah 

River Site and with Hanford National Laboratory in radiochemical development projects. Some 

of this work was done in the K-1004 complex where they did bench scale work. 

The gaseous diffusion plants operated as if they were one site. Paducah served as the feed plant. 

Paducah released uranium to Oak Ridge, uranium that K-25 enriched to 1% or 1.5%. This was 

some of the source of the Tc-99. K-25 did reactor returns, but the main source was Paducah. 

K-25 did a limited amount of work for others in foreign countries, but not a lot (e.g., Cogema 

reactor returns). 

TRANSFER BETWEEN FACILITIES 

There was a lot of interchanging between facilities, especially before the Bechtel Jacobs days. 

This involved transferring workers between K-25 and the other Oak Ridge sites (e.g., X-10 and 

Y-12). Workers went from one site to the other, but often stayed as an employee at K-25. Prior 

to 1989, they actually were employed at different places, depending on where there was funding 

to hire them. 

Prior to 1989, Lockheed Martin or Martin Marietta often moved workers between K-25, Y-12, 

and X-10. When jobs slowed down at one site, the other sites were generally hiring and a worker 

could pick up a job there. It was mentioned that K-25 had some supervising responsibilities for 

environmental monitoring at the other Oak Ridge sites. 

Workers employed at the K-25 Site were loaned out to either X-10 or Y-12, but the K-25 

employee continued to work through his K-25 reporting chain and was provided with K-25 

support. 

Paducah fed materials to Portsmouth and K-25, and K-25 personnel were involved in the 

material transfer. Tc-99 came primarily from the reactor returns. 
Effective Date: Revision No. Document No. Page No. 

May 31, 2007 0 SCA-TR-TASK1-0017 85 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

K-25 relied on Y-12 and X-10 mainly for product and feed transfers, and for some technical 

support. 

One interviewee recalled that there was relatively little transferring until the mid-1980s when the 

plant shut down. Even then, there were still only a small percentage of workers who transferred 

between facilities. 

. 

In regard to the relationship between K-25, Paducah, and Portsmouth, one interviewee 

responded that there was not too much transferring between sites in the earlier years. There 

were Engineers that did work at all three sites, however. One interesting example is that 

Engineers were assigned strike duty in Portsmouth during a strike in the early 1990s, and some 

of them did instrument work with contaminated instrumentation. When asked if these facilities 

shared parts and equipment, the interviewee responded that this was not normally done, though 

there was some equipment shipped during the CIP/CUP, and a lot of spare parts were left that 

came from Paducah and Portsmouth after shutdown. A lot of these parts were not 

decontaminated at K-25. 

Another interviewee reported in the 1980s, they had an assignment at Y-12 in the 1515U 

complex. There was movement between facilities at the K-25 Site. One interviewee 

remembered taking tours and going to K-33. 

In the early days, they took their dosimeters with them wherever they went. 

RADIOLOGICAL CONTROL (RADCON) AND HEALTH PHYSICS ASPECTS 

There was no robust Radiological Control program at K-25 until about 1989. Four technicians 

were responsible for radiological monitoring at the K-25 Site for the first 40 years. Initially, 

individuals worked by job request. With the improvement of the RadCon program, more 

technicians were hired. There are currently about 60 technicians provided by an outside 

contractor. The site is currently in a Surveillance and Maintenance mode operating 24 hours per 

day, 7 days per week. The site is currently in a D&D mode. Two technicians are maintained on 

the back shift. Only about six areas on the whole K-25 Site had any reliable internal dose 

coworker data before 1989. By the mid-1980s, coworker doses averaged about 60 mrem. 

At K-25, uranium fell under the jurisdiction of the Radiation Control (Health Physics 

Department) organization, based on its properties as an alpha emitter, as a radioactive material. 

The Heath Physics Group did the monitoring and analysis for radiological exposure to uranium, 

which included urinalysis, whole-body counting, and airborne area and personal sampling. The 

Industrial Hygiene Department was notified if results indicated a health concern from a heavy 

metal perspective. Both the Industrial Hygiene and the Health Physics Departments reported 

directly to the Medical Department. Routine area and integrated personal sampling was 

performed by the Industrial Hygiene Department for non-radiological air contaminants, and 

results were recorded and provided to management and the individual sampled. 

In the early days in K-1210, there were many cylinders and most were stored rather 

indiscriminately. As the interviewee was taking samples there and in the K-1205 areas, while 

wearing all the appropriate PPE (lab coat, cotton gloves, hard hat, safety glasses, and 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

86 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

respirator—which the one interviewee indicated she religiously wore), others would come 

around and watch, but these onlookers did not have on any PPE protection. The interviewee 

indicated that she adhered to the dress out instruction and did as the procedure prescribed as she 

did this sampling. When the onlookers left the area, they were not monitored for radiation 

contamination before going home. This occurred in the mid- to late-1970s timeframe. The 

interviewee also did cylinder sampling in the K-1010 building, as well as in the K-1200 complex 

areas. There were a lot of workers in the K-1200 area buildings. 

There was a lack of knowledge in the 1970s about what materials were radiologically 

contaminated or contaminated with chemicals or toxics. It was assumed that if you took a 

shower at the end of the day, everything was fine. Showering was required in areas where it was 

needed. In the late 1980s, there was less emphasis on showering, since the production processes 

were shut down. After production shutdown, there was still a lot of processing of liquids that 

went to Paducah. Bioassay sampling was done appropriately for what was known at the time. 

Select workers received annual whole-body counts. 

Around 1976–1977, there was a dosimeter that had a detachable picture badge. The dosimeter 

badge was dropped off at a dosimeter rack before leaving and the picture badge was taken home. 

Later on, they stopped doing it this way, and workers would take home both their dosimeters and 

their picture badges, and bring them back in the following day. 

There were no friskers until 1976. At this point in time, workers did not wear PPE unless they 

were going into the pots. There were no health physics (HP) technicians onsite at that time. In 

the late 1970s, there were only two HPs. One interviewee recalled that the HPs came around 

only once every 6 months. It wasn’t until 1986–1987 that HP coverage started to really improve 

and become more efficient. The new regulations resulted in a heightened awareness and concern 

by the HP Group. 

Bioassays were not routinely provided in the 1970s – only certain workers in certain jobs 

participated. The taking of urine bioassay was not started until 1980, when they first started 

taking baseline urine bioassay on workers who had internal exposures or were thought to have 

the potential for internal exposure. Whole-body counts and bioassay were done on workers 

involved in incidents. In the 1970s, bioassay was yet to become common at K-25. If workers 

were called in to have a urine bioassay, it usually reflected a concern about a higher potential for 

uranium uptake. 

It wasn’t until the early 1990s that Bechtel Jacobs started to provide each worker with radiation 

exposure feedback in the form of an annual personal radiation exposure summary. 

In the earlier days, operators did wear rubber gloves, aprons, and galoshes. Their hands still, 

however, looked pink. 

During the mid to late 1970s, several industrial hygiene and safety professionals were hired to 

address the increased demands of the cascade improvement/cascade upgrade (CIP/CUP) 

program, as well as to comply with the newly created Occupational Safety and Health Act of 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

87 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

1971. The number of industrial hygiene and safety employees remained constant until 1985, 

which is when all uranium enrichment at the K-25 Site ended. 

In the early days, workers were pretty much alone, and not really provided with much HP 

supervision. It wasn’t until the mid-1980s that HPs started to be increased. This was about the 

time of the shutdown of production in the gaseous diffusion plant. K-25 was shut down without 

workers wearing anti-Cs. About this time, friskers began to be used as boundary control 

monitors. 

The interviewees said they did not submit nasal smears. They all, however, did participate in the 

urine bioassay program. They indicated that the need for these was driven by the time they 

worked under a Radiation Work Permit (RWP), which did not start up until 1990 or so. At one 

point in the 1970s, bioassays for them were done quarterly. 

One of the interviewee said he worked in blue jeans, but did wear company shoes. They 

remembered that the one HP would bring a meter over once in a while in the late 1970s and 

check things out. K-770 was the radiologically contaminated waste yard. There was usually no 

check done on clothing. There was no one to even check if workers were wearing their gloves. 

When clothes got to the laundry, they were checked, but they did not check the individual 

worker. Work uniforms were laundered onsite. One interviewee did say that he showered every 

day. 

RWP and Special Work Permit (SWP) requirements as to who needed PPE, bioassay, 

dosimeters, RCT coverage, and entry/exit requirements were done on a building-specific basis 

and was decided by the building Supervisor. Local protocols were followed. The RWP process 

started at K-25 in 1989 for one interviewee. 

One interviewee recalled that he wore his film badge from the first day he arrived. In the 1970s, 

film badges were left on a rack before leaving for the day. Dosimetry processing was done at 

K-25. In the 1970s, the picture badge had the film inserted within it. Sometime in the 1970s, 

they transitioned to TLDs. Everybody was issued a TLD. In 1984, they installed a TLD reader 

at K-25. There were portals to control access for security. The guards, however, never checked 

for dosimeters. 

Workers were sent for a whole-body count if they knew they had received some internal dose 

exposure. 

One interviewee reported that he felt that Rad Safety did know what was hot and what was not 

hot. It was reported that Rad Safety was able to inspect most of the experimental equipment. 

Monitoring and “green tagging” of equipment, however, did not start until mid to late 1980s. In 

1991, Rad Safety began to find items that had been green tagged but were found to be 

contaminated. 

The first radiation-training course that those interviewed could recall was in 1988. The first Rad 

Worker II course at K-25 was offered in the early 1990s. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

88 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

One interviewee recalled entering an area where workers were wearing respirators and was told 

to stay away from the area. 

One interviewee was involved in monitoring the centrifuge machines. The interviewee reported 

wearing a dosimeter during these operations, and wearing a respirator when samples were pulled. 

The interviewee did not receive any radiation training for these jobs, but was Q-cleared. The 

interviewee learned how to sample the machines from the person who performed the task before 

her, and followed the procedure thereafter. The interviewee always wore PPE—cotton gloves, a 

respirator, a hard hat, safety glasses, and a lab coat—to take these samples. The degree of PPE 

protection was based on pre-surveys done by Rad Safe to identify radiation areas. 

Some interviewees indicated that they did eat, drink, and smoke in the break room that was a 

separate room in the middle of the work area. Sometimes they even would take their food back 

into the work area. Eating on the job was not a concern of the worker or management. 

One worker worked in K-131 and K-27, which was across the street from the Process Building. 

The Process Building had a cool area that would remain cool, even if it were 97o outside. They 

would go into the Process Building to cool down and didn’t think much about the contamination. 

The lack of concern about contamination was that way even up into the 1980s. But K-25 Site 

was a good place to work. The workers felt that had a good Medical Facility. They believed in 

what they were told. 

One interviewee noted that respirators were issued on an as needed basis, and stated that he was 

never issued or wore a respirator himself. Banana oil was used in the early years for respirator 

fit testing. He was allowed to eat, drink, and smoke in the immediate vicinity of radioactive 

material. 

Respirators should have been worn in the appropriate areas. Some workers would change out 

their respirators daily and dispose of them, while others did not seem to care much about it. 

Coveralls were issued in the 1972–1973 timeframe, but some workers preferred to wear their 

own blue jeans. 

In the northern end of K-1401, there was a Research and Development (R&D) area. You needed 

to have a reason to go there. 

There were radiological hazards when working within the converters. One worker had to do this 

often, and these areas were contaminated. 

There was no green tagging of radiation waste until the mid-1980s. 

Workers were allowed to take their dosimeters home with them. 

Posting of radiation areas was started post-1985. Workers in the Steam Plant worked around 

coal dust and ashes, and wore either a half-face mask or a respirator. Yellow rope and magenta 

and yellow radiation area signs were not evident at K-25 until the mid-1990s. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

89 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

When gaseous diffusion activities ended, there was a downsizing of the Industrial Hygiene and 

Health Physics Departments, with many professionals leaving to accept jobs at other Oak Ridge 

facilities. In 1990, based on a DOE initiative (Tiger Team Inspections), Industrial Hygiene, 

Safety, and Health Physics Organizations increased staffing to meet the new DOE requirements. 

Posting as defined by DOE orders and 10-CFR-835 was not implemented onsite until about 

1989. After 1989, every building with the potential for radiation exposure was suddenly posted. 

In earlier years, the areas may have been posted as Zone 1, Zone 2, and Zone 3 for 

contamination. 

Everybody was monitored with TLDs or bioassayed, where it was needed, from the late 1980s to 

1995, when the potential for exposure dropped significantly. In 1995, the local DOE 

representatives pushed to stop monitoring those workers who did not enter known radiation areas 

or areas of radiation or inhalation exposure, or who were suspected to have no potential for 

radiation exposure. As a result, health physics stopped badging workers who were not entering 

the radiation areas. Workers did get a personal neutron accident dosimeter (PNAD) if they were 

out in the field. 

It was mentioned that RCTs were the most likely workers to move around between K-1131 and 

K-1420. In the early days, there were only two HPs on the whole K-25 Site, and radiological 

control overview was very limited. One maintenance worker was mentioned as an individual 

who moved around a lot. Laborers were usually steady where they worked in the early days. 

Since 1989, respirators are used in areas where uranium dust or other airborne contaminants are 

present. This can be a full-face respirator in heavy dust areas, or half-face respirators in other 

areas. The RCP defines when the full-face respirators are needed. Workers often decide 

themselves when they think half-face respirators are needed, although the RCP may define this 

in some areas. 

There were significant quantities of Tc-99 even outside the area where it was processed. The 

cascades were highly contaminated with Tc-99, which was easily tracked throughout the 

facilities. Based on characterization data and waste profiling, Tc-99 is not high outside of the 

Purge Cascades (K-311-1, K-310-3, K-402-9, and K-402-8). Tc-99 was not processed per se. It 

is a radionuclide that could not be chemically separated during the plutonium and uranium 

recovery by the extraction (PUREX) process, and was subsequently fed into the process system 

as an impurity in the recycled uranium. 

Workers were often in the immediate vicinity of areas where work required PPE. For example, it 

was not unusual to find one worker wearing a respirator and several others working with him 

unprotected. It was indicated that showers and change room facilities were available to the 

workers, but there were no requirements concerning showering after work. Workers used to eat 

in lunchrooms and offices throughout the process buildings, drank from water fountains and 

coolers, ate candy bars and snacks, and drank soft drinks on the process floors, and smoked 

everywhere. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

90 of 191 

 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

There were x-rays done for non-destructive testing of welds. These x-ray areas were roped off. 

Most workers were not sure where this testing area was in K-1401. The site also had a 1.25 

MeV gamma Co-60 sealed source for calibration of the survey instruments. 

Things were not controlled by written procedures in the early days. The Radiological Control 

Program often did not provide appropriate field monitoring. It was extremely rare to see 

radiological monitoring occurring. For example, one individual who worked in Building K-1131 

for 3 years reported seeing RadCon monitoring only a few times. In about 1989–1990, there was 

an improvement in the overall safety programs at K-25. Field monitoring was conducted more 

routinely and workers received training. Although the Oak Ridge sites were run by the same 

contractor for many years, the safety program was not equivalent between Y-12, K-25, and X-10. 

X-10 had the best safety program of the three plants. Y-12 and K-25 originally had poor 

programs. 

Facilities creating the highest potential for exposure to radiation included the five major cascade 

buildings; a feed manufacturing plant; disassembly, decontamination, and cleaning facilities; 

maintenance buildings; uranium recovery facilities; numerous laboratories, pilot plants, and test 

facilities; the barrier manufacturing plant; smelters; and incinerators. 

Radionuclides other than uranium present at K-25 included americium, neptunium, plutonium, 

and technetium. These were mostly contaminates from reactor tails. There was thorium work 

done as a part of testing work for the Navy. 

The contamination within the K-1131 area was controlled by vacuuming and washing down 

floors and other accessible areas. This water flowed to Poplar Creek. Individuals liked to fish in 

this creek. If an area could not be decontaminated, it was painted to keep the contamination 

from going airborne. 

Building K-1131 was the Feed Manufacturing plant. The radiological conditions in this building 

were not good. This area handled green salt, yellowcake, or a blend of material. In some areas 

(e.g., on beams), green salt and yellowcake were often visible. 

While working on the fluid bed in K-1131, workers were required to wear lead aprons and finger 

rings, and were given a time limit for work in this area. There was also a Co-60 source in this 

building. 

Personnel were allowed to eat in the process area. In fact, cantinas were located in process 

buildings where personnel could order grilled or cooked food. Lunchrooms and drinking 

fountains were also available. The cafeteria (K-1002) was often found to be contaminated, 

because workers wore their coveralls and shoes from the process area into this area without 

changing. 

Dust masks or respirators weren’t always available. As a result, workers had the potential for 

inhaling airborne radioactive material. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

91 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Maintenance workers did not receive body counts prior to the 1970s. Individuals were selected 

at random for body counts prior to the 1970s. 

Personnel Protective Equipment (PPE) varied by location. In Buildings like K-25, K-27, and 

K-1131, workers wore company-issued coveralls, shoes, underwear, and socks. In K-1037, 

workers wore their personal clothing. At the Steam Plant, coveralls were required for work 

inside the boilers. In 1954, the union negotiated with the company to provide all workers with 

coveralls. 

Work around fluorine generators required heavy rubber gloves, safety glasses, plastic suits, and a 

face shield. 

There were issues with contaminated vehicles at K-25. 

RADIATION MONITORING 

The primary external dose received at K-25 comes from exposure in the cylinder yard. A 

measurable dose rate is also associated with the Building 1401 machining trap. This is primarily 

from Tc-99. 

K-25 currently has a DOELAP-accredited bioassay program; however, ORNL does the analysis 

on bioassay samples now. At one time, K-25 had its own analytical laboratory. ORNL is 

responsible for processing the Harshaw brand TLDs for K-25, and they hold the external 

dosimetry DOELAP accreditation. K-25 also works under ORNL’s external dosimetry TBD and 

DOELAP Accreditation. 

When Special Bioassay samples were requested, a 24-hour bioassay sample was collected. 

Beta/gamma dosimetry was on a quarterly exchange cycle starting in 1989. Prior to this, there 

were individuals on up to a monthly exchange cycle. Neutron dosimeters (i.e., TLDs) were on a 

quarterly exchange cycle. 

Personnel were directed to wear beta/gamma dosimeters on the chest. Neutron dosimeters were 

worn on a belt at the waist. Currently, personnel are allowed to take dosimeters home. ORNL 

conducted a study of background on dosimeters that are taken home by workers. As a result of 

the study, they subtract a standard background. 

If the dosimeter is accidentally left at home, an individual can get a temporary dosimeter, which 

is linkable back to the individual. 

All employees were externally monitored through the 1980s until about 1995. At that time, 

assignment of dosimeters to administrative support personnel was discontinued. Only personnel 

qualified as Radiological Workers are assigned a regular dosimeter. Others may be issued a 

Nuclear Accident Dosimeter, which would be processed only in the case of a nuclear criticality 

accident. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

92 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Neutron monitoring depended on the area to which you were assigned. Neutron dosimetry was 

assigned to personnel in non-destructive analysis who worked with neutron sources, those 

working in the cylinder yards, and those working in Building K-25. Since 1989, a correction 

factor of 10 has been used for the limited neutron exposure at K-25. Prior to that, there is no 

information on historical procedures. 

TSCA (the kiln), the AVLIS, and material from the Building 1420 are considered Type S 

materials for internal dosimetry. Building 1401 has a furnace in the basement, which also had 

Type S material. Bioassay for Buildings 1401 and 1420 include uranium and technetium. 

During waste-handling operations, individuals are potentially exposed to plutonium, neptunium, 

tritium, and uranium. Thorium may also be present in waste. There may be high levels of 

tritium in the TSCA waste as a result of accepting material from across the DOE complex. 

A lapel air-sample monitoring program was implemented by BJC. Lapels are placed on 1 out of 

every 3 to 5 individuals, where necessary. With areas containing transuranics, lapels are placed 

on all personnel. The site uses derived air concentration (DAC) hour tracking for thorium and 

transuranics to compensate for technology shortfalls in the bioassay program. Respiratory 

protection factors are considered when tracking dose. 

In cases where urine samples are compromised, dose is assigned using the lapel air monitoring 

results or by assigning coworker dose. 

INTERNAL DOSIMETRY 

Airborne uranium and other radionuclides were often present, creating a potential for inhalation. 

The interviewee provided a copy of a memo from contractor personnel dated June 4, 1963, 

which indicated that 20.5 pounds of scale containing 34.8% uranium were removed from the 

walls and bottom of K-1302 vent stack. The same contractor also reported two additional 

occasions that uranium-contaminated scales were removed from the same vent. An October 4, 

1963, memo reported the removal of 8 lbs of solids containing 6.3% of U- 235. A November 5, 

1963, memo reported the removal of a total of 75 lbs of solids containing 2.7% U-235. The 

interviewee also provided a copy of a memorandum dated September 18, 1958, that highlights 

the venting loss of 58,854 grams of uranium and 407 grams of U-235 from building K-1131. 

The interviewee commented that, “One must wonder how much went into the lungs of the 

workers.” 

A ChemRisk Report of March 2000 to the Tennessee Department of Health concluded that 

airborne uranium releases from K-25 were 50% higher than the values reported by DOE. It was 

estimated that 10,713 kilograms of uranium were released, compared to the 1,600 kilograms 

reported by DOE. 

Bioassays were not provided in the 1970s. Urine bioassays were not taken until 1980, when they 

were used on workers who had internal exposures or when the workers were thought to have the 

potential for internal exposure. We were provided with a copy of a letter dated October 11, 

1991, from Martin Marietta’s Fred Mynatt, VP of Compliance, Evaluations, and Policy, to 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

93 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Dr. D.L. Cragle, an epidemiologist with Oak Ridge Associated Universities, detailing the 

limitations of the use of pre-1989 worker radiation exposure data in epidemiological studies. He 

concluded that this data was not sufficient for dose assessment. 

Tc-99 was present in some K-25 buildings, especially in the 1970s. The meters used then, 

however, could not detect Tc-99, so bioassay was not always done in these areas if it was not 

realized that TC-99 was present. A RadCon individual determined if there was Tc-99 in the K25 building. Later, Tc-99 appeared in K-27, K-29, and K-31. 

One interviewee reported that whole-body counting was done once a year at K-25 for employees 

who worked in areas of potentially high contamination when the whole-body counting trailer 

was set up at K-25. Later, workers went to ORNL for their whole-body counts. This, however, 

was done on a low percentage of workers at K-25. 

Urinalysis bioassays were commonly done, but rarely did they do fecal samples. Nasal smears 

were commonly taken to detect Tc-99. Workers were also monitored for the presence of Tc-99 

in their hair, where it tended to accumulate and represented a potential for inhalation or scalp 

exposure. 

The supervisors knew that workers were receiving internal dose from their work environment. It 

was not uncommon for workers to have 12,000 cpm on their hands. Bioassay was done for U 

and Pu. Of particular concern were manual operations, such as when workers shoveled ash into 

hoppers. One interviewee read of this happening in K-1131 in the early 1950s. 

In regards to a question about the basis for determining who was put on a bioassay program, the 

following was offered. Bioassay was required for workers in K-1401 who had the potential for 

exposure to uranium and Tc-99. Bioassay was also required in K-1420, which had the potential 

for exposure to neptunium, tritium, uranium, and thorium. Tritium was high in some areas, and 

often came into the building from other facilities and DOE sites. 

Once bioassay sampling began, there were generally no gaps in covering individuals that worked 

in areas where internal dose potential existed. Starting in 1989, the Radiological Control Permits 

(RCPs) set out the requirements for who needed to be bioassayed, and only those individuals had 

urine bioassays done. In the early days, they did urine bioassays on everyone just to try to ensure 

that they captured workers who were receiving internal dose uptakes. 

In regard to a question about whether 24-hour bioassay samples were considered routine, 

interviewees confirmed that they either took 24-hour urine collections or simulated 24-hour urine 

collections (void in the morning and void in the evening). 

Processing of the urine bioassays was done in the earlier days by BWXT, UT Battelle, or Bechtel 

Jacobs. Currently they are done at X-10. 

When asked about whether there is a routine fecal sampling program at K-25, it was learned that 

since 1989, this is done only when employees are working on classified uranium projects. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

94 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

In regards to a question about U-233 processing and storage at the K-25 Site, it was mentioned 

that there were different chemical forms of uranium that could have included U-233. In two 

areas specifically, Class S solubility U was handled or processed. This involved one small area 

of Building K-1420 in the calciner area, where the temperature got up to 860°. Also in K-1401, 

Super S solubility U could have been present. Materials were burned in burners in the Toxic 

Substances Control Act (TSCA) area. Workers had to go inside the kiln itself to scrape and 

knock off the slag. This definitely would have represented exposure to Class S uranium. 

Workers, however, were only bioassayed for uranium, but this did not start until about 1989. 

When asked about isotopic fractions of U-234, U-235, U-236, and U-238, it was explained that 

DAC-hour tracking has been used since 1989 when Bechtel Jacobs came in and tightened up the 

health physics program. DAC-hour exposure tracking has been helpful in determining these 

isotopic fractions, especially if there is no data to determine the maximum dose. It is used to 

look into what is really a reasonable dose to assign to the worker so exposed. 

According to an interviewee, NIOSH uses a default value of Type S in dose reconstructions. 

This is the most claimant-favorable solubility for calculation of dose. One interviewee indicated 

that this is not necessarily so. He indicated that it depends on the site, if the absorption type is 

known, and what is claimant-favorable. The favorability is based on the cancer organ. Type S 

solubility is most favorable for the lung. 

If needed, personnel were sent to Y-12 or ORNL for a whole-body count. Routine counts were 

conducted, first in a portable trailer on the K-25 Site, but later at ORNL. 

Stack discharges and treatment discharges were routine at K-25. Specific facilities involved 

were all the Purges and Process Buildings, some of the Process Auxiliaries, the Sewage Plant, 

the K-1420 Facilities, all the discharges to K-1407-B&C Pond, and the RCW process. 

RWPs required bioassay samples to be taken if the worker was expected to get a dose greater 

than 100 mrem. The type of bioassay is determined based on a characterization of the area. At 

times, it seemed that bioassay was overdone. However, urinalysis was the most effective means 

to identify if workers were receiving internal dose. 

When an injury occurred in a radiological area, the individual was asked to submit a Special 

Bioassay sample. Incidents were documented in e-mails, which were placed in an individual’s 

personal exposure file. An interviewee did not know if this is true historically; however, he did 

indicate that this has been true since the 1990s. 

Dosimeters didn’t measure inhalation dose, and there was potential for internal exposure at the 

K-25 Site. According to one interviewee, however, there really wasn’t much potential for 

environmental dose. The Health Physics Department tried to get a handle on occupational 

environmental dose, but it was just too difficult. It was hard to handle inhalation dose from 

airborne contamination that was not a direct result of local workplace releases, because HP 

didn’t know how long they were exposed and in what location. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

95 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

EXTERNAL DOSIMETRY 

The first film badge remembered was the Lazarus badge, which was turned in every day and 

picked up the next morning. The badge was read during the night and recorded. The 

interviewee was not aware of where the dosimeters were turned in or who processed them. Later 

when TLDs came in, the TLDs were changed quarterly. At that point, dosimeters could be taken 

home at night and brought back in the morning. Since Bechtel Jacobs took over in 1998, ORNL 

has been doing the TLD processing. 

Workers were instructed to wear their film badge at chest level on the front of their bodies. In 

the 1970s, workers left their dosimeters on racks and did not take them home. They only took 

home their cover security badge. When they transitioned to TLDs in the 1980s, workers were 

allowed to take their dosimeters home with them along with the attached security badge. There 

was a problem with TB screening, whereby workers’ badges would receive non-workplace dose 

on them. In regards to possible directional problems with the dosimeter not really capturing the 

dose from behind or above, this was usually only a problem with Dosimetry personnel who used 

calibration sources. 

In the early days, most workers did not move around a lot. The exception to this was the security 

guards, the samplers, and the RCTs that did move around all over their facilities, as well as 

throughout all the K-25 Site facilities. 

During the period when the site was actively engaged in the gaseous diffusion process, the 

Dosimetry group was in the analytical labs and in K-1004 (now torn down). Instrument analysis 

(Electron microscopy) was done in K-1006 on samples from the centrifuge machines and various 

components. 

One RCT indicated that external dose at K-25 was very low. The LLD of the dosimeter was 

14 mrem. He felt that external dose was not a problem at K-25, except in a few limited areas. 

Extremity monitoring was not routinely used at K-25. The most likely source of external 

environmental exposure would be from the cylinder yards. 

One interviewee reported that nothing was posted as a radiation area or contamination area in the 

early days (1970–mid 1980s). In the early days, there was a < 0.1 mr/hour LLDs of the radiation 

survey meters that were used in the uranium production areas; < 0.1 mr/hour was considered to 

be comparable to ~10,000 dpm for uranium contamination. 

Radiation surveys were done by radiation monitors. Prior to the 1980s, the Supervisors were 

trained, but the operators who usually did the surveys were not always trained. Sometimes the 

Supervisors did the surveys. 

When asked about movement between K-25 and other Oak Ridge sites, one interviewee 

indicated that some personnel traveled, as well as transferred, between sites a lot. Fire and 

security personnel move around the sites a lot. Their film badges and later their TLDs were 

combined to their security badge, so they had to have them with them as they moved around. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

96 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Radiation surveys were done, but the guidelines kept changing. One interviewee remembered a 

spot survey on an old capped drain where contamination was detected. In the late 1980s, the 

guidelines were cut in half. 

From the 1980s on, workers performing a similar task were all monitored. Workers were trained 

as to what type of PPE to use in contamination areas, even before 1980. The use of PPE, 

however, according to one interviewee, was not consistent between different areas. The use of 

coworker assigned dose at K-25 was not a common practice. Most workers had their own 

dosimeters or received urine bioassay, when needed. 

Dosimetry badges went with the employees from one place to another. Each site read its own 

dosimeter. Workers were notified only if there was a positive reading or something was wrong. 

For some time now, each worker has been receiving an annual report of his or her radiation 

exposure. Whole-body counts were also conducted. The whole-body counter was in a portable 

trailer at K-25. Later K-25 workers were sent to ORNL for their whole-body counts. Wholebody counting was generally done every 2 years. 

After 1990, dosimeter and bioassay results were provided to each worker annually. The 

interviewees reported that they did receive an annual personal radiation exposure report. 

Logbooks were kept that showed daily the date, location, and job of individual workers, which 

included notes on type of PPE worn, contamination levels on the floors, and any air-sampling 

data. 

The highest external dose occurred in areas around the compressor seals. They did use dosimeter 

rings when doing these tasks. 

When asked about potential exposure from other radiation sources, it was indicated that there are 

none now. Since those being interviewed were not there in the earlier days, they had no 

additional information to offer. 

Neutron monitoring was done in some of the cylinder yard areas, in the non-destructive assay 

(NDA) open areas, and parts of K-25 wherever a cylinder was stored. 

Higher external doses were found around the cylinder yards or in the cylinder building. Now 

that the cylinders are gone, there is no longer much potential for external dose. 

In regard to contractor and subcontractor dosimeter monitoring, it as explained that Bechtel 

Jacobs badged contractor and subcontractors like everyone else. Prior to 1989, these workers got 

only accident dosimeters. These accident dosimeters were not read unless there was a criticality 

accident. Not many visitors, however, went into areas where the dose could exceed 50 mrem. It 

was recalled that the Dose Reconstruction System (DRS) may have data on a monthly basis. 

Individuals were directed to wear their dosimeters on the upper torso at chest level. If they were 

issued a neutron albedo dosimeter, they usually wore it on their belt at the midline of the body. 

UT-Battelle does the TLD readouts. Currently workers are allowed to take their TLDs home 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

97 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

with them. Health Physics could tell if they took their badge home or not. If a worker forgot 

his/her TLD, they were issued a temporary TLD, and once they returned their issued TLD, the 

results of both were merged. Some unread badges were held in the Dosimetry Office. At 

designated intervals, the TLDs were shipped to UT Battelle and the K-25 Site followed UT 

Battelle external dose procedures. 

There were two sources of neutron exposure. There was some neutron exposure in the gaseous 

diffusion plant around the cylinders. In addition, there was a Co-60 source that had a high curie 

content. The neutron-to-photon ratio, where applicable, is documented as a part of the As Low 

as Reasonably Achievable (ALARA) reviews. The approximate ratio is 5:1 photon to neutron. 

There was also a PuBe source that was stored in a big can of paraffin. The interviewees never 

saw it used much. 

Currently K-25 is using the Harshaw TLD. For those workers suspected of being exposed to 

neutrons, the TLDs are done quarterly. 

In addition, there was an iridium source that was used extensively for radiography. 

Building K-1401 was where the whole radiography group was located and did their radiography. 

This work was done under the auspices of a Nuclear Regulatory Commission (NRC) license, and 

in more recent years, NRC came in to review the doses. 

One interviewee remembers an old Photo badge with a hole in it and the film packet hung behind 

the hole. The worker wearing it was decontaminating an area/equipment. A contaminated chip 

of uranium stuck in the hole. The radiation exposure the worker received resulted in a 

blackening of the film under the area of the hole in the film badge packet. This was determined 

by a RadCon investigation. 

There were sealed sources on the K-25 Site. More details of this should be in the records in the 

K-25 records archive, or in the records sent to the Atlanta Archives. The Records folks know 

where they are. 

A radiation dosimetry specialist looked at the dosimeters regularly, and it was he who developed 

the foil dosimeters. 

POTENTIAL MISSED DOSE 

The two worst buildings for exposure to radioactive material were K-1131 and K-1420. K-1131 

was the feed building, and exposure was of particular concern when processing reactor returns. 

Building K-1420 housed pickling operations, an acid bath, a decontamination facility, and 

operations of various types. Work was finished in K-1131 in 1999. Work there (when it was in 

operation) was nasty. Work during the D&D of K-1131 was controlled with engineered controls, 

administrative controls, and the selection of proper PPE. No internal doses were received and 

any external dose would have been minimal (10-20 mrem). Work on environmental cleanup of 

K-1420 was to be completed on December 20, 2006. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

98 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Another hot facility not on the K-25 Site Profile building list is the centrifuge facility. They did 

some hot runs that resulted in some hot steam releases. These were the K-1200, K-1210, and 

K1220 facilities. The K-1210 facility is still on the K-25 Site. 

There is missed dose in K-33. PCB oil accumulated in the troughs installed along the seams of 

the building air ducts. When the workers drained the troughs, this PCB fluid, with concentrated 

radiological contamination, dripped onto the floor and workers walked through these areas where 

it could be tracked. The whole building ventilation came through these vents. Also, the 

management staff often gave away small cards with uranium samples attached to the cards as 

souvenirs. 

It was not uncommon to see yellow power on the floor and working surfaces (ammonium 

diuranate, the precursor to yellow cake). This was not regulated before 1976—until the 

implementation of the Uranium Mill Tailings Remedial Action (UMTRA) Program. 

There were contamination problems in K-131 and K-633, which had the test loops. Radioactive 

contamination was common in K-1030, K0135, and K-1024. K-1413 did radioactive material 

experiments and served as one of the development labs. These activities resulted in frequent 

contamination problems. 

Frequent airborne contamination problems were common while doing cell change-outs in the 

CIP/CUP. Some maintenance jobs had airborne contamination problems. 

Workers, especially in the earlier days, worked all across the K-25 Site. 

K-1121 and K-1131 had a lot of contamination and were the first ones to be torn down. K-1420 

had two large rollup doors at opposite ends of the building. There were times when you looked 

down the aisle between these two doors that you couldn’t see from one door to the next, because 

of the urynal nitrate fog that often hung up near the ceiling and sometimes settled near the 

working areas. Conolux paint was painted over the floors to seal the contamination under the 

paint layer. One of the painters at the time would also put some Americoat epoxy paint down. It 

had to be periodically stripped and reapplied. They used blowguns to blow off the paint and 

chunks went all over K-1420. This occurred around the 1975 time period. The K-1401 ceiling 

was cleaned with blowguns; painters did not wear respirators while blowing down the ceilings. 

Painters applied Americoat epoxy paint after ceilings were cleaned. 

There was an incinerator (K1421) behind Building K-1420. Plastic garbage bags containing 

contaminated waste were burned in this incinerator, usually in the evening hours after sundown. 

This produced a thick black smoke. All that kept the plastic bags closed was a yellow shakerlike wire around the neck of the bag. These bags were staged in the SW corner of K-1420 

Building awaiting incineration. This incinerator was operated as late as 1985. The TSCA 

Incinerator replaced this operation and it went into operation about 1990s. 

L Lab was a hot area. One of the interviewees who worked in L Lab in 1984 stated that he only 

wore coveralls, but was not told to wear a respirator during his work activities. He did wear a 

TLD on his chest above waist level. At that point in time, it was the bubble albedo TLD 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

99 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

dosimeter that was issued in the late 1980s. He received no special instructions, however, on 

how to protect himself from radiological contaminants in L lab. 

There was waste disposal stuff all over the site. 

Workers had to clean out the K-1420 sludge ponds by dredging dirt and sludge out of them. This 

dirt and sludge was then mixed with concrete and put in plastic-lined, metal 55-gallon drums. 

These drums were then sent to an area called the “Valley of the Drums.” At one point, workers 

were asked to double the production of processed waste drums and as a result, the waste drums 

often did not get a plastic liner installed before the sludge and concrete was put into them. As a 

result, some of these waste drums started leaking. The drums were eventually moved to a 

landfill site. This drum processing area no longer exists. 

It was mentioned that X-10 had things a lot more dangerous than that at K-25, which, in the 

opinion of the interviewees, are not well recorded. 

One interviewee told of a claimant’s wife who was told that there was no Pu at Paducah. After 

he passed away, there was an analysis of his bones and they found Pu at levels 2,000 times the 

limit. Y-12 was also reported to be worse than K-25. 

In the K-25 machine shops, five out of the five workers that were assigned a particular toolgrinding job have subsequently developed brain cancer. 

In the early days of the 1970s, there were no posted radiation areas. There were heavy-duty 

gamma exposures in the cylinder yards, as well as some neutron exposure. 

One interviewee indicated that there were lots and lots of UF6 in the K-25 plant and at other 

locations as well. The reactor returns in K-33 represented another potential for radiation 

exposure. Tc-99 was also present. When they fed in the uranium, it came out in various 

enrichments. These were then fed into the cascades and then all were finally hooked together. 

There was no highly enriched uranium (HEU) office in 1964. Prior to 1964, there was HEU 

present in K-25 Building and it had to be constantly cleaned up. Around 1985–1986, the Facility 

Safety Representative (FSR) started to oversee these areas. Currently, there are Technical Safety 

Reviews (TSRs), Accelerated Safety Analyses (ASAs), and Preliminary Hazard Screenings 

(PHSs), but these did not begin until after most of the production had closed down. 

One interviewee remembered that he and other workers sweated so bad that they got green stains 

around their wrists. The work was hot and nasty and involved working in environments with a 

lot of powder dust. 

In K-1074 where the cascades were operating, there was lots of hydrogen fluoride and uranium. 

One interviewee thought the cylinder yards were not too bad for presenting any problem with 

high doses. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

100 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

When they took cells off line or worked on the wet air pumps, they pulled an exhaust on the seal 

to keep the seal pressure lower. If there was uranium present, it would get mixed with the oil 

and would be hard to clean out. Liquid freon was also leaked. The most contaminated area for 

this kind of work was in K-33. 

It was pointed out that every time workers took a cell off line, if the pressure was too high, there 

would be a puff of smoke coming out of it. If the pressure was negative, then wet air went into 

the cell. 

CONTAMINATION 

K-1420 was the most contaminated place on the K-25 Site. This was where all the 

decontamination and uranium recovery was conducted. In the early days, workers just wore 

coveralls and dusted them off before leaving work areas. The floor in K-1420 was so 

contaminated that it was hard to clean off the contamination. Painters, therefore, just painted 

over the contamination to fix it in place. They used red lead paint coating. In the mid 1980s, 

workers began to use lapel monitors and air sampling became more routine. 

Building K-1410 housed a small equipment decontamination facility. This was the 

decontamination facility for the entire plant site in the 1950s and 1960s. K-1410 was also 

involved in decontamination of equipment for K-25, K-27, K-413, K-1131, and K-1231 

Buildings. A lot of the decontamination operations were done on the outside of the 

1410 Building. Drains within the building and soil surrounding the area were assumed to be 

contaminated. Building K-1410 was not large enough to handle some of the converters, so the 

K-1420 facility was built. Building K-1420 was involved in converter disassembly, or deheading of converters, and decontamination of this equipment. 

There were also issues associated with the leakage from cylinders that were in storage. 

In the K-1420 decontamination facility in the 1970s and even into the 1980s, if a worker got his 

hand contaminated, he did not know it as there was no monitoring for contamination at that time. 

British Nuclear Fuels (BNFL) surge drums were usually pretty tight. Contamination just was not 

measured. If you needed a part, a worker would just go over to the K-1420 Building or to K-33 

and get the part without any survey being done. In the old jet cells, uranium was found around 

the roof. It wasn’t until 1986–1987 that they started to “green tag” parts to indicate they could 

be released for public use. 

In the early days, the use of change rooms and showers by non-craft workers was minimal. The 

craft folks were generally the only ones to frisk themselves prior to leaving the areas. The noncraft workers wore personal clothing and often did not have coveralls. Coveralls came in later 

and in the mid-1980s, these non-craft workers were issued khaki work clothes. The khakis were 

laundered and cleaned by C&S. The RadCon group monitored these workers to ensure their 

khakis were below prescribed release limits before they left for the laundry facility. At ORNL, 

everyone had khaki work clothes. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

101 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

The types of operations at K-25 that involved radionuclides, where the potential for 

contamination existed, were primarily from uranium and Tc-99. Uranium was stored in the K-25 

building. Contamination problems did occur in the equipment and utilities areas. Materials 

removed from the reactors (reactor tails) were taken to the cascades. There were fission products 

from the cascade process. During the fluorination process (HF4 to HF6) radium did come out. 

They identified the fluorination area as one area with contamination problems. Field 

characterization started in the late 1980s. 

Workers in the blend tower in K-1037 were not required to take showers in the early days. In 

1960–1962, it was reported by one interviewee that workers went on strike, because they wanted 

to have company-issued shoes and coveralls. As a result of the strike, they finally got coveralls. 

Another interviewee said he wore company coveralls, as did all the operators, and that he never 

left the site without showering. He recalled that later, in the 1979–1989 timeframe, the HPs and 

the environmental engineers wore company-issued khakis. 

If there were contamination incidents, the workers were either brought to the decontamination 

facility (Building 1008D) or taken to the Medical Department, if there were injuries associated 

with the incident. 

Starting in the 1980s, shoe surveys were done for workers in contaminated areas to prevent the 

tracking of contamination into clean areas. There were routine radiological monitoring surveys 

in the cafeteria. In about the early 1960s, there was unmonitored tracking of uranium 

contamination out of production areas. This, however, was not a problem in the 1980s. 

Assigning respirator use for workers evolved from multi-user, to single user, to single use. In the 

early years workers would reuse their respirators. Respirators were stored in cabinets. There 

was intermittent cleaning of respirators between uses. In the early days, workers kept their 

respirators around their neck. 

Coveralls were the primary PPE, along with the use of respirators, welding masks, aprons, and 

gloves. One interviewee recalled inspecting motors and seal failures while only wearing street 

clothes. 

As time evolved, PPE requirements became more controlled, single-use more common, and Rad 

Safety began to monitor its use in controlled areas. 

PPE and safety requirements were communicated daily to workers. There were some special 

briefings as well. This all evolved into the current radiation protection program. PPE 

requirements were not always consistent between different departments. 

When asked about situations where workers were in the immediate vicinity of areas where work 

required PPE, one interviewee responding by saying that this was a tricky question. He indicated 

that they have people today in Level B wearing PPE, and people 6 feet away across a radiation 

warning rope in Level D not wearing PPE. It's always been that way. The safety professionals 

established the job requirements and the boundaries. They determined the appropriate actions to 

take. He remembered being 10 feet away from mechanics in respirators doing seal changes, and 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

102 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

wearing his work clothes. The primary change has been in contamination control and 

monitoring. The practice still occurs, but it's currently better controlled. 

It was indicated that showers and change room facilities were available to the workers, and that 

showers were mandatory for certain workers. 

When asked about eating, drinking, and smoking in the immediate vicinity of radioactive 

material, one interviewee noted that he remembered that the term “contamination area” is 

relatively new. People ate in lunchrooms and offices throughout the process buildings, drank 

from water fountains and coolers on the process floors, and smoked everywhere. This ended in 

the 1980s. When asked if workers were allowed to have food or beverages at their immediate 

work location, the response was generally no, although some (very few) did eat at their 

workbenches. 

In Building K-1423 during a release, there was yellow cake that leaked on the floor. A 

supervisor was on his way out to evacuate the area and walked over the yellow cake, tracking 

contamination down the hall. The tracking path was surveyed by RadCon personnel, and it was 

determined that the contamination levels were below limits for the hallways. This faded away 

fairly soon, however. 

One interviewee reported that there was contamination in L Lab and in the analytical 

laboratories. 

The ventilation ductwork was contaminated in Building 1401. 

Friskers started to be used in the late 1980s in some areas. By the early 1990s, when the new 

DOE Order took effect, Rad Safety began to rope off any area that was a contamination area. 

Personnel contamination monitors (PCMs) were used starting in the 1990s with the introduction 

of the Berthold. Prior to the implementation of PCMs, a Model 177 alpha/beta/gamma 

instrument was used to frisk worker’s hands and clothing prior to exiting work areas. If 

contamination was found, they had to go back and clean up before leaving the site. Many people 

were found with contamination on their hands. 

There were contamination problems in K-131 and K-633, which had the test loops. Radium was 

common in K-1030 and K-1035, as well as in K-1024. K-1413 performed radiation experiments 

and served as a development lab. These activities resulted in frequent contamination problems, 

especially for workers. 

Fluorine leaks occurred at the end of the uranium enrichment process, which involved uranium 

contamination. This was during the stage when UF4 (Green Salt) was being converted into UF6. 

Building K-1420 was the decontamination facility. In the 1980s, the HP Group did routine floor 

surveys. They had a lunchroom in K-1420, and they kept it clean; however, the break room in 

K-1420 was found to be contaminated at one time. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

103 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

One habit of workers was to cook their food on top of the incinerator, which was a “High 

Contamination Area.” 

Respirators were assigned for use in areas of frequent airborne radiological contamination. 

Based on the level and type of air contaminant(s), half-mask respirators were used in lieu of fullface respirators. Respirators were cleaned and issued on site, and were distributed from a 

controlled issue point. 

Personnel protective equipment (PPE) used for the various K-25 operations were usually 

coveralls, gloves, safety shoes and glasses, and hearing protection (i.e., ear plugs) in the early 

years. Use of PPE was more or less job-specific, and depended on specific IH or HP instruction. 

Showers were used at the end of each work shift. Most workers did shower and change into 

personal clothing before leaving for home. 

Material got a green tag (called the radiation clearance tag) if it was shown that the exposure 

level was <0.1 mr/hr. In order to release equipment and objects to the public, it had to be less 

than 5,000 dpm or less than 1,000 transferable dpm. 

It was not until the mid 1990s that RadCon and their contractor support staff posted and roped 

off contamination in areas that up to that point had not been posted or controlled. This was 

based on the old guideline limits. 

Dust masks were usually worn in the 1980s, but not for work in radiologically contaminated 

areas. They were worn more to prevent inhalation of mold. There were bird droppings and dead 

birds on the plant floor. Histoplasmosis, however, was not much of a problem. 

Most early workers started wearing a half-face mask for most jobs. If the job required greater 

protection, then they would put on their full-face respirator. If HP required the use of full-face 

respirators, then they were worn. 

One interviewee indicated that he worked daily in contaminated areas while he was performing 

his HP duties. 

Technicium-99 was tracked easily. Technicium-99 leaked from the seals when a mechanic 

changed them out. The worker would put his tools into his toolbox, and it would be picked up 

later in non-contaminated areas and spread Tc-99 contamination there. Rad Safety corrected 

this, when it was realized this was happening, by creating the concept of a “dedicated” 

contaminated work place toolbox. The toolbox was not removed from the contaminated area. 

The changed part was placed in a sealed package before it was brought out. Technicium-99 was 

only a leakage problem in the end room of K-27 Building and K-29 Building. Later, this also 

became a problem in K-31 and K-33. 

Cross contamination of groundwater lines contributed to contamination of drinking water 

fountains, which contributed to uranium ingestion and ingestions also resulting from intake 

associated with cesium-137 and strontium-90 from the X-10 releases into the K-25 sanitary 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

104 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

water system. Also, there were several incidences of cross-connections between sanitary 

(drinking) water and cooling water from the uranium enrichment processes. 

In the 1970s and 1980s, workers were allowed to eat, drink, or smoke in the immediate vicinity 

of the radioactive materials (e.g., contamination area) and were allowed to have food or 

beverages at their immediate work location. 

When exiting from the process areas, workers were directed to wash their hands. Some 

personnel were required to shower at the end of the day. Showering was optional for others. At 

K-25, there were showers and change rooms in those facilities that had contamination problems. 

Workers changed into personal clothing (including shoes) before leaving for home. 

A pilot study on contamination control was initiated in Building K-1420. This involved donning 

and doffing anti-contamination clothing and exit monitoring. 

There were some fires and explosions that occurred at K-25 that did result in contamination 

incidents. 

In K-33, they used sanitary waste water as the feed for their water needs. In one situation, the 

backflow valve failed and some of the facility coolant water that got too hot in temperature and 

could not re-circulate ended up going back into the storm drain. In K-33, they had to pump a lot 

of air through the facility all the time. In these situations, they did not use lapel air samplers. 

In K-33, there were seal blowouts when they were trying to see how much pressure the seals 

could hold. Other people were around the worker testing the seal and would get exposed during 

the blowout. They tried to shut it down, but the brakes didn’t work. There were 3,300 motors 

that had these kinds of seals. 

Seal exhaust pumps often leaked, and workers would have to paint them to fix the 

contamination. In K-31 and K-33, there wasn’t much of this painting done. The building was 

just too big and too long. In K-1420, they painted the floor a lot. 

When asked about the kinds of egress monitoring that had been implemented historically, it was 

mentioned that firemen and guards had their own uniforms. Supervisors would keep their 

respirators in their offices and wore their own street clothes. Most workers did change their 

respirators every 30 days. One of the interviewees said he cleaned his respirator with alcohol to 

clean it up. He always used a full-face respirator, but could get a half-mask, if ever needed. 

Workers on the crawling line or those that went in to stop leaks wore full-face respirators. If a 

worker was just pulling a sample, then he often did not wear a respirator. No gloves were worn 

if they did not suspect contamination to be present. 

In the cascades, UF6 was a problem when valves were closed. Sometimes a light gas would 

bubble up. It was soon realized that value control procedures were needed if UF6 was involved. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

105 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

In 1978, the potassium hydroxide (KOH) scrubbers would fill up with UF6 gas and the workers 

would have to burp it to prevent buildup. In the late 1980s to early 1990s, TSCA began to 

change things and more sampling was done around the scrubbers. 

Sometimes contamination occurred when taking down the cell to remove the D-Blade. These 

events were usually written up in the area control room logs. Contamination occurred to some 

extent every time a worker shut down a cell. There were disk brakes involved and asbestos was 

released. The disk brakes had a gas bearing seal, which only had a life span of 10 years or so. 

In regards to a question about types of posting designations, one interviewee recalled a job where 

it was necessary to cut holes in the lines to the stacks. The worker would have to use a 40-foot 

line to get the pieces out of the line. 

In one operation, one interview recalled a situation where they were purging a cell and a worker 

had to crawl back into the cell where there were concentrations of hydrogen fluoride. He 

remembered they had to sweep up all the HF. The dust was so thick, it would almost knock you 

down. They had to use a fan to help blow it all out. There were three 30-foot openings. All you 

could do was blow away the HF and thus help to dilute it. 

In one incident, a hole was punched into an expansion joint and white UO2 smoke filled up the 

entire building. 

Old fly ash often went into a pile – it was a different world in those days. 

One skin burn incident occurred with a worker. The worker was lowered by a rope around his 

ankles to allow him to put a pipe wrench on a handle and close it. He received hydrogen fluoride 

burns on all exposed areas of his skin. He retired a while back and now is deceased. 

One current Bechtel Jacobs’s employee used to work on feed in the K-1131 Building and could 

tell you more about his experiences. 

Leaks were common when workers were pulling samples. 

There was a big spill in K-27; however, one interviewee could not remember any big events in 

K-33. 

When asked about containment failures, one interviewee recalled a situation where a worker was 

pulling a sample. The job required the wearing of a respirator. He was in the pipe gallery 

without a respirator when the event took place. The worker had to come out quickly, dry off, 

don his respirator, and clean up the spill. When he had finished the cleanup, he then took a 

shower. 

When there was a big environmental release at one of the other Oak Ridge sites, the 

environmental engineers found that there was a notable increase in radiological contamination 

found in the potable water for the K-25 Site, since their source of water was the Clinch River. 

As soon as it was noted, the water intakes into the K-25 Site were closed down, and clean 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

106 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

potable water was brought into the K-25 Site for employee use until it was safe to go back on 

water intake from the Clinch River. 

There was an analysis of the drinking water at K-25, which found that it was not contaminated. 

DECONTAMINATION AND DECOMMISSIONING 

It was explained that the extent of D&D operations at K-25 involved contaminated facilities or 

portions of facilities that have been decontaminated and decommissioned routinely since the 

1940s. There have been capital projects since day one at K-25 that removed, covered, or 

decontaminated equipment and structures at this site. Only beginning in the 1990s was this 

considered D&D. Prior to that, it was considered demolition in preparation for new construction. 

When asked about the type of environmental restoration and waste clean-up operations that 

occurred at K-25, the following were recalled. The first environmental restoration project that 

was recalled was the “Environmental Protection and Safety Modifications, Phase I” project in 

1981. This was the start of the Batch Plant for K-1407-B&C Ponds cleanup and the Central 

Neutralization Facility. There have been many since. When asked about the methods of 

contamination control that were used at these facilities, one interviewee responded that his first 

radiation protection course was on March 16, 1989. It was recalled that this was the day, 

approximately, that the K-25 Site began working under the new radiation protection 

regulations that are known today as 10 CFR 835. Before then, you would have to talk to the 

radiation technicians. Personally, the interviewee recalled that he had worn a dosimeter every 

working day of his career, had two baseline bioassays, but never had a whole- or partial-body 

count. Another interviewee recalled that he did not have any baseline bioassays that he recalled. 

His primary years of exposure (1975–1980) never resulted in a request for these special exams or 

any notification of his external exposure from the dosimeter. He remembered that in the late 

1970s, many of the Operations and Maintenance personnel were on a routine bioassay program 

(depending upon their job duties), but he did not remember if people were sent for whole-body 

counts. 

In response to a question about burning or incineration activities at K-25, one interviewee 

responded that there were such operations. There was the K-1421 Incinerator, the K-1420 Flame 

Tower, and something in K-101, K-131, and K-601 in the early days (1940s). 

WASTE DISPOSAL 

In response to a question about treatment and disposal activities for radioactive waste one 

interviewee provided some detailed information. Disposal of radioactive waste went to 

K-1070-A, which was the burial ground for most radioactive waste. K-1070-F was the waste 

site for clean construction debris. K-770 was the scrap yard for radioactive scrap metal. 

K-1093/K-1094 received the clean scrap metal. There were also some other debris sites 

around the plant that were remnants from the original construction days (JA Jones Area, 

Demolition Placement Area) and other construction times (K-901-A Construction Debris). 

Also, K-1407 waste ponds were the disposal basins for radioactive sludges. The White Wing 

Scrap Yard was used for clean scrap metal, until it was shutdown and K-1093/94 opened. A 
Effective Date: Revision No. Document No. Page No. 

May 31, 2007 0 SCA-TR-TASK1-0017 107 of 191 

 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

few cylinders were also disposed of (shot with a rifle) in K-901-A Pond. Other places for 

waste storage were K-720 Slough–Powerhouse Ash, and K-901-A, the Holding Pond for 

RCW sludges. Treatment was a nebulous term used at K-25. K-1407 was a Pit, radioactive 

acids neutralization area. Several facilities that treated RCW and made sludges/sediments of 

various types included sewage treatment at K-1203 and K-7 10. The Central Neutralization 

Facility is the current treatment system. 

Disposal criteria did change significantly over time. In the early years radioactive waste was 

buried with no containers, and then later went into drums and boxes (wood, cardboard, and 

metal). 

When asked if there was a hold up of radioactive material in piping and ventilation, one 

interviewee indicated that this was a problem. It was detected via NDA and visual observation. 

Sometimes it was detected by instrumentation. 

INCIDENTS/UNUSUAL OCCURRENCES 

Accidental releases and equipment repairs often lead to injuries and excessive exposures, which 

resulted in burns and respiratory complications. Workers often went home with contaminated 

clothing, because they were never warned of the dangers. 

The K-1401 Motor Shop was the place you went to when you wanted something fixed. K-31/33 

was another location for motor repairs. When they tore down these motors, there were all kinds 

of yellowcake powder (ammonium diuranite) that fell out and piled up to 1-inch thick. Folks, 

however, did not stir up too much dust. No one wore respirators in these areas. In the motor 

shop over a 7-year period, over 600 motors were brought from K-31 and K-33 process buildings 

to K-1401 for repairs or preventative maintenance. The motors were not repaired in the process 

building, but only in K-1401. These Motor Shops were the most up-to-date motor repair shops 

in the Eastern United States. 

. 

Motors were then taken to a degreasing tank, and would come back nice and clean. The starter 

and rotor would be dipped in cleaner to remove the oil and grease. Then they would use cranes 

to lift them into a spraying booth. At this point, workers would don their respirators. They 

would use plant compressed air with water running in from the back to clean the parts. After 

they dipped the parts, they would dry it with plant air. At that point, a HP would come in and the 

instrument would peg. So he got another and it pegged, too. 

There was a means of documenting incidents and/or non-routine occurrences. The Information 

Corrective Actions Tracking System (ICATS) was used to document such occurrences. The 

interviewees assumed that any dose received and reported could be traceable. In terms of offnormal situations, IH didn’t monitor for personnel radiation exposures, but focused on 

monitoring for chemical and physical agents. 

Not much could be recalled on the threshold for incident reports. It was assumed that such 

thresholds were the maximum permissible concentrations (MPCs) or the DACs. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

108 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

The interviewees indicated that there are databases compiled of incidents at K-25, and they felt 

that this data is generally available through the QA Group. 

In 1981, there was a converter fire in the K-29 Building. A lot of workers were involved. 

Phosgene gas was released. There was crossover in the respirator air input line and the worker 

started breathing pure nitrogen. 

Transformer fires occurred at K-1420. When one transformer blew, it was so extensive an 

explosion that it blew out the sides of the containment fence. 

One interviewee reported that there were releases of airborne uranium in K-1131, but they were 

not particularly high. 

The biggest concern for internal dose involved an airborne release and inhalation of uranium. 

There was an incident in Building K-1200 (the Centrifuge Building). In a room that was lined 

with lead sheetrock wall, the door was not properly secured, and the source beam got past the 

leaded door and hit a meter on the desk of an HP worker. 

There was a dumpster fire in K-1037. Building K-1037 housed the AVLIS Program. ORNL 

personnel brought over a uranium sample to use in the AVLIS project. After use, they threw it 

into a dumpster for disposal, and the uranium oxide caught fire. 

In the northwest corner of K-1420, they burned contaminated clothing in an incinerator. This 

area often had a lot of radiological “hot” spots. 

The documentation of incidents and/or non-routine occurrences in the early days often meant 

reporting it to the Plant Shift Superintendent (PSS). One interviewee remembers being at a PSS 

morning meeting (sunrise service) called when he was informed that there had been an incident. 

He immediately went over to see what had happened. Such incidents were recorded in logbooks. 

These logbooks are no longer around in the local work areas and are likely over in Archives. A 

look through these log books would provide some interesting reading, and would reveal a lot 

about what releases occurred and the contamination levels involved. 

Incidents and/or non-routine occurrences were logged into logbooks, maintenance records, safety 

reports, quarterly reports, etc. These records are maintained in active and inactive records, at 

least those that are left. Clean-up operations were conducted after the incident as much as was 

necessary to remove the contamination. 

Documentation of off-normal situations (e.g., spills) documentation depended on the person 

spilling the materials or witnessing it. 

ICATS is the system that records incidents and unusual event reports. This may include survey 

or field data, or formal incident reports. If there are issues associated with personnel exposure, 

that data that will find its way back into the individual worker file, as well as the dose 

determined for the individual. Where the only data comes from an area monitor but individuals 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

109 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

received no dose, the information would not get into the worker’s individual file. Such nonroutine files exist back to 2001. 

One group of interviewees indicated that there were plenty of fires and explosions at K-25. 

Another interviewee indicated that there were not too many fires or explosions. One interviewee 

advised that if more information is needed on fires, the Fire Department should be consulted. He 

indicated that they keep good records. But the interviewee did not remember any specifically. The 

big fire in his career was the K-29 converter fire. 

There was one fire in K-33. A transformer blew and the fire storm blew off the door panels of 

the transformer. One interviewee said he was close to it, but he was leaving when it happened, 

just saw it, and was not hurt. 

An additional report on off-site emissions is a report, entitled Oak Ridge Health Studies, Phase I, 

Feasibility Study, A Summary of Historical Activities on the Oak Ridge Reservation, published in 

April 1993 (Copy not provided during the K-25 Site Visit.) This includes information 

concerning off-site emissions of hazardous materials. It was published by Chem Risk (A 

Division of McLaren and Hart). It can be ordered by writing to 113 Atlanta Avenue, Alameda 

California, 94501. 

There was a fire in the K-31 ventilation ducts in the 1972–1973 timeframe. These ducts supplied 

fresh air to all areas of the K-31 operating floor. Over the years, waste oil had accumulated in 

the air ducts, and during a job that required the use of oxygen/acetylene torches, oil in the ducts 

caught fire. The ventilation fans blowing fresh air through the ducts caused the oil fire to spread 

smoke throughout the building. The oil in these ducts was PCB-contaminated. Workers 

breathed this contaminated smoke. After 2 days, there was fallout detected in Berea, Kentucky, 

over 100 miles away. 

There were fires at the K-25 Site in K-25, K-315, K-310 (took the roof off the building), K-29, 

and K-413. In K-413, a worker cut the wrong pipe and the resulting fire created a glowing chuck 

of metal. 

In K-335, a hole was opened in a compressor and a fire ball (C-fire) ensured that took the roof 

off. This C-fire involved three cells with release of CF3. The explosion was created by a spark 

that came out of the cell. 

AUDITS 

Internal DOE audits began in the 1980s. In the late 1980s, Tiger Team Audits were conducted at 

K-25. Nuclear safety concerns hit the fan in a big way in 1989 as Admiral James Watkins, then 

the DOE Secretary, initiated a rapid tightening of the regulations and radiation safety controls. It 

was pointed out that in more recent years, DOE has conducted an audit of the Health and Safety 

program at K-25 every 2 years. There were routine audits internally at K-25, as well as those 

done by DOE. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

110 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

There was a recent DOE Inspector General audit of records that began in January 2006 and is 

still ongoing. It involved looking at how things are being done now in the bioassay program 

(i.e., are bioassays being done and are we DOELAP-accredited). 

The interviewees stated that the K-25 Site did not destroy any safety-related records in the past. 

Procedures and documents were available to workers who were expected to enter radiological 

contamination areas, chemical areas, and/or physical hazard areas. 

ENVIRONMENTAL DOSE AND MONITORING 

Environmental Dose 

In the 1970s, there was no monitoring done on stack releases. Incidents at Paducah finally 

alerted the K-25 Rad Safety staff that these needed to be monitored. It wasn’t until the late 

1980s or even the early 1990s before stack monitors started to do a good job of monitoring stack 

releases. At this point in time, the Rad Safe staff put up air monitors and began to do water 

sampling. 

If a worker needed to purge a cell, he had to vent it out the stack. 

If waste drums became full in the decontamination facility, construction engineers would just dig 

a pit and bury the waste there on site. Some of the liquid coming out of the cylinders also had to 

be drained into these ponds and it reacted with the water. There were lots of this type of 

radioactive waste and no record kept of what was used. For many years, this waste was not 

labeled and no one tracked where it was going. If it involved the R&D facilities, we didn’t ask, 

and they would say, “Let’s try this,” and we did it. 

From 1963–1993, if a piece of equipment or part was needed, workers would just cut them out, 

not knowing if they were contaminated or not. This didn’t change much until monitoring started 

in the late 1980s. 

One interviewee remembered a hands-on operation involving uranium at the K-770 radiation 

waste yard. A compressor, with only a canvas cover on each end, was being loaded onto a truck. 

The compressor was covered with a tarp. It was taken to K-1420 Building where something hit 

it and waste water from the compressor drained into columns at the bottom of the K-1420 

Building. In Building K-1401, it was later disassembled and then put back together again. 

Another incident remembered involving hands-on operations with uranium involved a K-25 Site 

known as the “Valley of the Drums.” This disposal area never worked very well. Workers 

would take sediments and put them into drums. When the drums later rusted, they began to leak. 

In the 1970s and 1980s, there was little effort to monitor releases from the K-25 Site incinerators. 

In these early days, whatever was thought to be capable of being burned was incinerated. It 

wasn’t until the TSCA Incinerator was completed and received its certification that monitoring 

of the incinerator releases became much more closely controlled and monitored. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

111 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Environmental Issues 

The Pond Waste Management Program ensured that pond waste areas were posted with air 

monitors. If Rad Safety personnel detected elevated levels, they would investigate the source of 

the problem. 

The incinerator in K-1421 had few controls in the early days, and anything that could burn was 

incinerated there. 

There were a few minor incinerators in operation over time at K-25. The interviewees all 

presumed that these were used for waste materials. The TSCA Incinerator was the major one at 

the K-25 Site. 

The interviewees did not have much to offer on any situations where a major environmental 

release occurred at the site that resulted in an evacuation. 

There was a problem with cross connections of potable and process water lines (e.g., K-1401), 

which was discovered in 1986. Sr-90 and Cs-137 were detected in the drinking water as a result 

of contamination with process water. The company made an announcement that personnel were 

not to drink the water. Pregnant women were further instructed to wash their hands. Bottled 

water was brought in to serve as drinking water. The problem was resolved by a change in the 

engineering design of the system. Around the same time period, plastic covers were put over 

drinking fountains in the process areas. 

There were routine releases on a weekly basis as a result of purging the cascades. The process 

buildings had a 30-ft stack. On humid nights, the off gas from the stack would flow downward 

to the ground adjacent to the building. Off gas could be seen up to 3⁄4 of a mile away. As a result 

of these releases, some of the buildings’ roofs were found contaminated (e.g., K-25, K-31, and 

Pump Station). 

There are underground and street-level steam lines running between the buildings. Cooling 

towers, as well as manholes, often released steam. The manholes were positioned on the 

sidewalks, where workers often walked during breaks and/or lunch. 

TSCA was originally designed to handle low-level radioactive waste, but was expanded to 

include other toxic materials and mixed wastes. 

K-25 had numerous disposal areas and burial grounds, including the areas near K-631, K-1007, 

K-1070A, and K-1420. K-770 was a dumping site for contaminated debris. There were several 

waste ponds located onsite containing radioactive and chemical waste. Barrels with waste were 

stored on the east side of the K-25 plant. 

Radionuclides identified in the outside areas of K-25 include uranium, technetium, strontium, 

cesium, thorium, and plutonium. These are related to the releases over the years including 

airborne releases and spills. Material has contaminated the waterways. A few cases of 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

112 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

contaminated deer are identified each year, when deer are monitored after hunting. The deer are 

monitored for surface contamination, as well as deposition of material in their organs. 

In 1984, there was a fire in Building K-29 that resulted in a large release to the atmosphere. 

Workers recall the plume was yellowish in color. 

Due to the large number of operations and facilities at K-25 over its entire period of operations, 

and due to incomplete records, the interviewees felt some potential hazards may not have been 

identified. 

Hundreds of accidental releases of UF6 and other hazardous materials probably occurred, often 

resulting in releases to the environment. Some contaminants may have migrated offsite. 

There were broken windows in the process buildings. 

Environmental Monitoring 

Pre-1970s, there was little environmental monitoring performed. Environmental monitoring 

reports started in the late 1970s and increased through the 1980s. 

There are currently 6 to 8 air monitors around the K-25 Site. The Annual Site Environmental 

Report (ASER) tells exactly where these air monitors are positioned. Some of the more current 

of these reports (within the past 10 years) can be viewed on the web at 

http://ornl.gov/sci/env_rpt. As a general observation, most current environmental monitoring is 

done for compliance (environmental regulations and DOE Orders) and to properly record dose to 

public (as opposed to employee exposure). This is based on data from the mid-1980s on. There 

is not much historical data prior to that. 

The 2006 Annual Environmental Monitoring Report is very similar to the 1995 Annual 

Environmental Monitoring Report. Not much has changed during these years. An individual 

was assigned as the interface to ORNL UT-Battelle (UT-B) who had the responsibility 

reservation-wide to develop the Oak Ridge Reservation Environmental Monitoring Plan and the 

annual report. This interface manager is one of Bechtel Jacobs’s Environmental Compliance and 

Protection Leads assigned to ETTP. A female manager at ORNL is in charge of the reservationwide environmental monitoring program. She is the Program Manager and is responsible for 

preparing the Oak Ridge Reservation Annual Environmental Report. 

In the earlier years, Lockheed Martin pulled all the site environmental monitoring data together 

into the annual environmental monitoring reports. Now, ORNL UT-B Environmental 

Compliance on behalf of the DOE Oak Ridge Reservation Environmental Compliance office 

coordinates the reservation-wide reporting, trending, and dose assessments. The ORNL UT-B 

Program Manager is interested in dose assessments and any important environmental changes at 

all the Oak Ridge sites. ORNL UT-B Environmental Sciences Division oversees the 

environmental data/fish populations in Mitchell Branch, in accordance with a subcontract with 

BJC. Improvement has been noted within Mitchell Branch over the past number of years. Most 

environmental monitoring currently is done for environmental compliance (e.g., to meet the 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

113 of 191 

 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

NESHAPs level of 10 mrem/year and DOE Order 5400.5). Main effluent charges are currently 

below the decontamination guidelines (DCGs) and are compliant with DOE Order 5400.5. 

BJC environmental compliance, BWXT-Y-12 Plant environmental compliance, and the UT-B 

ORNL Program Manager work together to develop the reservation-wide environmental 

monitoring plan in support of the DOE Federal Building environmental compliance staff. 

Permit-required monitoring has changed over the years. For example, prior to the mid-1980s, 

there were only three outfalls on the Y-12 NPDES permit. Today, there are probably over 200 

outfalls being monitored at Y-12. 

After 1998, Bechtel Jacobs beefed up the radiation safety and industrial safety/hygiene program. 

The Tennessee Department of Environment and Conservation/DOE environmental oversight 

office (TDEC DOE Oversight) handles overview and reporting mostly offsite, and monitors dose 

around the cylinder yards. 

Environmental monitoring stations located on the K-25 Site have stayed about the same over the 

years. ORNL also manages some monitoring stations around the K-25 Site for use in the 

reservation-wide reporting. 

Significant Episodic Releases 

There have been two episodic releases in the past several years that involved activation of the 

Emergency Operations Center (EOC). In the early 2000s, there was a small fluorine release. 

There were no reportable quantities, according to the Environmental Protection Agency (EPA) 

standards, and the EOC was involved in the response. The State EOC was also involved. In 

2004, there was also a Na release at a site managed by a reindustrialization tenant (TOXCO). 

Again, the emergency response effort was handled by the EOC. 

There have been no substantial spills of radioactive materials, at least during the Bechtel Jacobs 

period of operations. There was an incident that occurred about 2003, when some radioactive 

material was released on a public roadway while transferring waste from ONRL to the EMWMF. 

The roadway had to be closed until it could be resurfaced or decontaminated. There have been 

periodic thermal relief vent openings at the TSCA Incinerator typically caused by power failures, 

but releases from these events are very low. 

From a historic perspective, there may have been other releases at the site such as UF6, but the 

interviewees had no first-hand knowledge of these events. K-25 doesn’t currently monitor for 

hydrogen fluoride. 

In the recent past, the highest reportable dose to the public was 2–3 mrem from site radionuclide 

air emissions. This is compared to the EPA standard of 10 mrem/year (air pathway) and DOE 

standard of 100 mrem/year (for all pathways). 

About 2–3 years ago, there was an incident that involved the release of more than a reportable 

quantity (greater than 1 pound) of asbestos that fell from insulated piping. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

114 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Routine Environmental Releases 

NESHAP requires monitoring if a point source’s potential emissions exceed 0.1 mrem/year. The 

ORR ambient air-monitoring program converts air concentration data into dose to demonstrate 

that a member of the public will not receive dose from the release of unmonitored and fugitive 

emissions. There is no real-time monitoring for folks outside the site near such releases. 

During D&D operations, there is, of course, potential for releases. The HP personnel have been 

able to show that these doses are not significant, and these low levels are confirmed through the 

Environmental Compliance ambient air monitoring stations. Any environmental accidents are 

reportable under NESHAP as well. NESHAP is based on dose to the members of the public. At 

the TSCA Incinerator, they do a full sweep and monitor for all radionuclides that make up nearly 

100% of the total dose that might occur. 

Control of Environmental Releases 

HP data is used to estimate fugitive releases from buildings that may occur through building 

ventilation systems. Area monitors are used to detect radionuclide concentrations inside the 

buildings. If the concentrations exceed 10% of the DAC, emissions from the building are 

calculated using the measured concentrations and the building ventilation rates. 

Types of sampling done include TLD monitoring near cylinder yards, water monitoring, air 

samples, stack samples, and groundwater samples. From this data, dose calculations are 

performed. 

Before waste is brought onto the site for incineration, it must be analyzed to the waste 

acceptance criteria. This analysis can cost as much as $50,000 per shipment coming in. 

TSCA Incineration currently uses state-of-art stack monitors. Stack sampling is done 

isokinetically. However, in D&D areas, there are no stack monitors, because the emissions are 

fugitive in nature. Ambient air monitors are used to demonstrate that fugitive emissions are not 

significant. 

TSCA Incineration operations are highly regulated. The TSCA Incinerator over time has gotten 

a lot of scrutiny. 

RadCon does not routinely calculate environmental doses. They do calculate doses to workers 

from employee monitoring. The interviewee’s work scope addresses potential dose to the public 

and insuring compliance with regulations. RadCon addresses worker exposures. 

There are aerial fly-over surveys conducted periodically that can be used to identify hot spots. 

External environmental radiation levels are/have been monitored, and the TDEC DOE-Oversight 

Office also collects external radiation data. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

115 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Disposal criteria have changed over time at K-25. Prior to the early 1980s, rad wastewater went 

into ponds that were later buried. Currently, wastewater has to go to a NPDES-permitted or 

RCRA facility and be actively monitored. Solid D&D waste goes to DOE Environmental 

Management Waste Management Facility (EMWMF) (onsite CERCLA disposal cell) and the Y12 landfills. Most incinerator ash is inorganic. Most legacy waste at the K-25 Site is now gone. 

Audits and Environmental Compliance Reviews 

Bechtel Jacobs gets at least nine TDEC Inspections per year. The inspections include Resource 

Conservation and Recovery Act (RCRA), the Clean Air Act, and the Clean Water Act. There are 

also DOE audits that are done periodically. The TDEC DOE Oversight Team also conducts 

walkdowns onsite on a periodic basis. The TDEC also monitors offsite releases to the public, as 

well as some TLD measurements around the cylinder yards. The TDEC DOE Oversight office 

reports to the Environmental Enforcement office in Knoxville, Tennessee. There is also a Site 

Specific Advisory Board that monitors the environmental programs in Oak Ridge, including 

ETTP. 

INDUSTRIAL HYGIENE/CHEMICAL EXPOSURES 

The K-25 safety organization did interact with subcontractors when they came on site. The IH 

group had the responsibility to monitor their activities. Safety issues were enforced and IH was 

aware of what was going on. IH coverage was during the day shift only, but they were on call, if 

needed. Dosimeters were distributed to employees by the HP organization, and the dosimeters 

were exchanged quarterly. Finger dosimeters and other types of dosimeters were issued for 

individuals working in specialized activities as needed for monitoring purposes. 

Periodically, professional assistance was provided to other Oak Ridge, Paducah, and Portsmouth 

sites. For example, some K-25 industrial hygienists were sent on loan for short periods of time 

(1–2 weeks) to assist with assessments and provide subject matter expertise. While away from 

the site, K-25 Site radiological dosimeters were worn. Some of the K-25 workers were also lent 

out to work primarily at either X-10 or Y-12, and rarely at Paducah and Portsmouth. 

Over the years, K-25 in some situations received assistance and support for health and safety 

professionals and craft labor fromY-12 and X-10. 

All IH interviewees reported that their job responsibilities took them all over the K-25 Site. 

Their jobs usually did not involve radioactive materials, but they were measured and monitored. 

Health Physics did ensure that they were monitored with uranium bioassay. They worked mostly 

with toxic substances and non-radiological materials. The interviewees of the IH Group reported 

that the radionuclide program at the K-25 Site was managed by the HP Group. In regard to a 

question about uranium being handled in the immediate vicinity of beryllium, the interviewees 

stated that beryllium was rarely used at the K-25 Site, primarily as a part of a metal alloy in some 

specialized equipment parts. 

The IH personnel did not do radiation monitoring. The HP Group did the radiation monitoring in 

those situations. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

116 of 191 

 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Beryllium was a problem at K-25. Beryllium was stored in K-25 in the early days. 

All of the compressor blades used in the Process Compressors were alloyed with beryllium.
 

During the “tipping” operation, where the compressor blades were machined to specified size, 

machining dust from this operation migrated throughout K-1401. Workers developed chronic 

beryllium disease (CBD). There was also a beryllium problem in K-701, where there was a pile 

up of beryllium powder. A beryllium prevention program was started in 1995–1996. Today we 

know of six workers who have chronic beryllium disease and 23 are sensitized. 

Lapel/breathing-zone air monitoring was the primary method for industrial hygiene sampling. 

There were very few real-time monitors to detect airborne radiological contaminants in the early 

days. 

Chronic beryllium disease was long fought at the complex. Now DOE at K-25 recognizes the 

problem, and has designed a program to detect and diagnose beryllium among current and 

former workers. 

MAINTENANCE/CRAFTS/UTILITIES 

Maintenance work involved compressors, valves, seals, machines of all kinds, and working in 

and on gaseous diffusion process equipment and systems; also repair, removal, and replacement 

of pumps, pipe lines, and all types of mechanical equipment in air, chemical, process, sewer, 

sanitary, and cooling water systems inside, outside, and atop of most of the buildings on the 

K-25 Site. Exposures included radiation (internal and external), especially uranium and its 

daughter products; and a plethora of chemicals, dusts, fumes and mists. K-25 was involved in 

hundreds of different research programs and projects other than enriching uranium. Maintenance 

mechanics were closely involved in fabricating, installing, and maintaining equipment used by 

various scientists in carrying out their research. 

K-25 and K-27 enriched uranium to greater than 20%. As a result, maintenance workers were 

required to have an escort when entering these areas. 

Firemen and security guards sometimes went into radiation areas without their TLDs on. 

Sometimes they missed being monitored by urine bioassay. Firemen and security guards did 

wear respirators in some areas, but when a guard showed up, he may not have had a respirator 

with him. They usually did wear at least a dust mask, coveralls over their street clothes, and 

booties. When they took their coveralls off, however, they did not shower. In K-1420, there 

were showers that were regularly used. Construction workers were one of the biggest problems. 

Crafts personnel had the greatest tendency to move around a lot. 

Security guards and firemen provided coverage to the entire site and, therefore, could have 

entered any building. Maintenance personnel were shifted between Oak Ridge sites, depending 

on the work and their seniority. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

117 of 191 

 

 

 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Building K-1401 was the Machine Shop. It included the Jig and Fixture Shop and the Converter 

Shop. When working on the converters, one interviewee reported that there was a “scarfing off 

from the welds” and contaminated materials during this process went airborne. Workers were 

often sitting in those areas eating and drinking, dressed out in coveralls. There were 

contamination release episodes. This material was released in K-1401 in the Converter Shop. 

Equipment was sent over from K-1420 for machining in the K-1401 machine shop. At this 

point, there was no visible or removal contamination on the surface that did not exceed 2 mr/hr. 

Painters wore respirators and used gloves. They needed the proper safety gear. They painted 

over contamination on floors with magenta paint. In K-1301 (Nitrogen Plant), there is a large 

area painted with magenta paint, and signs are posted that read “Do Not Disturb.” 

Maintenance personnel worked in all buildings throughout the K-25 Site protected areas and also 

worked outside the facility fence line, such as at the Power Plant and the Central Water Plant. 

There were always high expectations to maintain production quotas. If an individual was 

assigned a task for a defined time and didn’t complete it on time, he was told it would be written 

up and reported. 

Routine and corrective maintenance were conducted on storage tanks, motors, pumps, etc. 

Maintenance personnel were often involved in retrofit activities that were done as frequently as 

daily on the cell equipment. For example, compressor seals had to be replaced very often. 

Respirators used by maintenance personnel were equipped with dust filters. 

There were additional shops and maintenance offices in K-131. 

Filter changes of the air-handling system, because of inherent radiation hazards, required job 

coverage by Radiation Monitors. 

After working on jobs with high-exposure potential, maintenance personnel were reassigned to a 

cold area for a period of time. 

Maintenance personnel often accessed areas that were normally inaccessible to production 

workers. For example, when a compressor de-bladed, a hole was often cut in the piping, and 

maintenance personnel crawled into the pipe to retrieve the metal pieces. 

DOSIMETRY RECORDS 

General 

K-25 records are filed by system number, but they only go back to 2001. These documents are 

searchable sometimes back to 1989. Hardcopy files are maintained in the library of K-1007. 

They are still in the process of collecting records as facilities onsite are being closed out. The 

library is archiving inactive files. Pre-1989 records during the era of Lockheed Martin have been 

sent to the St. Louis National Archive. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

118 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Bechtel Jacobs has computerized records that can be searched electronically. Bechtel Jacobs’s 

electronic system has tried to pull together all payrolls, medical, IH, and radiation-related files 

into one database. 

Individual worker radiation exposure files are maintained by the Dosimetry Department, and are 

filed by SSN and case number. There is restricted access to these personnel radiation exposure 

files. Hard copy data is available back to 2001. Electronic dosimetry information is available 

back to 1989. Records prior to 2001 are located in archives. Some have been sent to the Federal 

Records Center. It was explained that if an individual has been employed at the K-25 Site for a 

continuous period of time and did not have a break in employment of more than 5 yrs, then there 

is hard copy data for them. Unfortunately, records were archived a few years back for 

individuals who had not been here for more than 5 yrs or were deceased. 

If an individual worked at either Y-12 or ORNL prior to Bechtel Jacob’s contract, and then took 

a position with Bechtel Jacobs or one of their sub-contractors, then the records prior to Bechtel 

Jacobs stayed with the site. All records after Bechtel Jacob’s contract were Bechtel Jacob’s. If 

the individual was at K-25 and remained at K-25, then all electronic records were maintained by 

BJC. 

Bechtel Jacobs took control of the site in 1998. At this time, there was a large shuffle of 

employees between X-10, Y-12, and K-25. It is important to be aware that an individual’s 

exposure records on the K-25 Site only contain information from K-25. If they worked at the 

other facilities, records would also have to be obtained from these facilities. 

USEC workers are monitored by USEC under their own Radiation Protection Program (RPP). 

Separate requests are required to obtain dosimetry information for these individuals. The first 

year that USEC came back to this site, they were monitored by Bechtel Jacobs. Bechtel Jacobs’s 

management did not want to pay for their Dosimetry services, so they made DOE force USEC to 

work under their own RPP. At that time, they subcontracted with UT-Battelle for Dosimetry 

services (2004). 

When NIOSH requests the records for an EEOICPA claimant, the following records are 

provided: 

•	 All hard copy records – this includes what is in the worker’s dosimetry file. 

•	 These are delivered to C.J. Enterprises. 

•	 There is gap in data in the 1996–2000 timeframe, and we can’t find these records. These 

are the records for the old Decontamination Recovery System (DRS) in the old K-1420 

building. These records were maintained in a DRS Database that had data, but we no 

longer have access to that system of records. 

•	 All internal dose files. 

•	 All external dose files. 

•	 All hard copy records pertinent to the individual. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

119 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

There are no dosimetry records contained in the Medical records. 

Radiological Exposure Records 

Shallow dose currently is just beta/low-energy gamma (neutron dose is included if an individual 

had neutron dose). It has been that way since the late 1980s. Beta is determined from the open 

window but some is taken from the open window, and the slightly shielded area. There are very 

few neutron dosimeters processed at K-25. Up to the late 1980s, the shallow dose was equal to 

the beta plus photon dose. Deep dose was the sum of the photon and neutron dose. 

Field radiological records consist of air-sampling data, surveys, log sheets, and other field data. 

Manual surveys are stored by month, year, and survey number. There is now an electronic 

database used to maintain survey data. 

There are very few records of extremity monitoring. Multiple dosimeters were not generally 

used at K-25. There are some extremity badges, but these are only issued when special 

experiments are being undertaken. 

Pocket Ionization Chambers (PICs) were used at K-25, and can be filed either with the RWP or 

on manual log sheets in the personal dosimetry records. Manual login sheets are not in the 

Dosimetry Records. 

There is incident exposure data that includes internal dosimetry data, external dose data, and 

contamination data. 

The same system of records is maintained for subcontractors as are maintained for K-25 workers; 

however, we only forward any dose received by a subcontractor if a request is made to the K-25 

Records Manager. Everyone monitored by Bechtel Jacobs receives an Annual Report of their 

dose. That includes sub-contractors, as well as Bechtel Jacobs’ employees. 

Health and Ecology records fall under the CJ Enterprises responsibility, and are stored at Central 

records. 

Subcontractors are treated the same as all other employees with regard to monitoring. These 

records are maintained for the subcontractors at K-25 and are only provided upon request. 

Visitors are also monitored per the same criteria as employees. One difference with visitors is 

that prior dose history is not requested for these individuals. Visitor dosimetry has to be 

requested by the onsite person hosting the visitor. 

Union Carbide left all records at the site when they ended their contract. 

Field radiological records may be stored in the records vault at Building 1034A; however, many 

of the older records were shipped to the Federal Records Center in Atlanta. The records were not 

organized in any specific manner and would be difficult to find. K-1034-A is the inactive 

records vault. The active records vault is in K-1007. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

120 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Emergency Management documented fires and kept records in the 1980s and 1990s. 

One interviewee said he always wore his film badge and later his TDL got exposed, but he never 

got a report on his radiation/contamination exposure in the early days. Currently he does get an 

annual report summary of his radiation exposure history. 

Another interviewee indicated that Emergency Management should have good records on who 

responded to emergencies/incidents. The Fire Department also has logs on their response to 

incidents. 

Y-12 took over the old ANALIS laboratory database from the K-25 Labs for analytical samples 

prior to Project Environment Management System (PEMS) coming on board. 

In regards to a question about field characterization data, one interviewee responded that this was 

too big a question. There is much radiation data in the historical records, and numerous radiation 

survey reports and summary reports. RadCon has much of it, but there's been a lot of it archived 

in K-1034. Some of it may have been sent to Inactive Records offsite. 

One interviewee indicated that K-25 has lost Maintenance Records, Maintenance Work Orders, 

Engineering Service Orders, many logbooks (maintenance, operations, laboratory, safety, etc.), 

and big bunches of drawings. 

MEDICAL EXAMINATIONS 

K-25 employees were offered the opportunity to get an annual physical along with a chest x-ray, 

which could be declined on an individual basis. The Medical Department informed the workers 

of any health concerns. 

Workers were given routine annual physicals, which included a chest x-ray. Bechtel stopped the 

program in 1998. Medical services were reduced, except for emergencies or first aid. This was 

a management decision. Other DOE contractor sites in Oak Ridge continued full onsite medical 

coverage. 

Workers did receive annual physicals with a chest x-ray. In addition, their respirator was fittested and x-rayed at the same time. Hazmat/Asbestos workers received a chest x-ray twice a 

year; one time during their annual physical and another one 6 months later. They were not sent 

offsite to get their chest x-ray. The x-ray machine was mounted, so that the worker stood against 

the wall. The bucky system made a noise, so you knew when the unit was in operation. The 

same x-ray machine was used each year. 

If you were an asbestos worker, you got a chest x-ray during your annual physical, and another 

chest x-ray 6 months later. The asbestos testing was based on the Electrical Code. In 1979 and 

1980, the K-25 Site had to do asbestos fireproofing on 17 miles of underground cable, thus 

resulting in more potential for asbestos exposure. They would use a glove bag to take the 

asbestos off the rolls. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

121 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Workers were periodically called over to Medical and asked to have a whole-body count. This 

started in the early 1990s, but it was pointed out that not everyone had whole-body counts 

performed. 

X-rays were also given for respirator fit testing. 

Due to switching between K-25, Y-12, and X-10, medical records sometimes were not always 

centralized in one place. This was somewhat due, as well, to outsourcing mandates by DOE. 

Since 1989, when Bechtel Jacobs took over, medical records have been maintained and stored in 

Building K-1007. 

Workers got a physical examination each year, where you received an annual chest x-ray. One 

interviewee only remembered getting a physical with a chest x-ray once every 2 years. It was 

pointed out that much later, the interval for a chest x-ray became less frequent, depending on the 

age of the worker. In addition, if you were in jobs that required a respirator, you also got an 

x-ray fit test at the same time as the physical examination. Asbestos workers currently are not 

site employees – this work is done by contractor employees. 

One interviewee remembered going to the Medical Department twice, one time when he 

punctured his glove and the other when he caught his finger on a hook. 

One interviewee reported that he had an annual medical physical examination once each year, 

including a chest x-ray. The other interviewee said he received an annual physical only once 

every 2 years. This latter interviewee said that he did not wear a respirator, and did not get a 

chest x-ray for respirator fit testing. He did verify that those in the respiratory protection 

program did an x-ray for their fit test, as well as a chest x-ray, during their annual physical 

examination. After age 40, workers got 1 chest x-ray per year. As the new regulations were 

issued in the late 1980s, there were fewer chest x-rays done. 

Another interviewee recalled receiving a medical examination with chest x-ray annually. 

Medical also did do x-rays for fit testing. In 1989, Bechtel Jacobs scaled down the Medical 

Program. Emergency personnel do, however, continue to receive annual medical examinations. 

Nurse practitioners now try to do many of the things that physicians used to do, but their scope is 

much more limited. 

A physician interviewee, who had been the physician at K-25 in the past, established the 

minimum physical requirements for the K-25 Site when he was staff physician. He carried those 

requirements with him to Concentra, and is using most of the same programs that he used at 

K-25. 

For the early years at K-25 (1946–1989), medical exams were done every year for radiation 

workers and included a chest x-ray. In the early years, physical exams were optional, but most 

workers felt it was a good program and had regular annual physicals. One interviewee stated 

that at K-25 from 1987 to the end of 1998, HazMat, Asbestos, Respirator, and other program 

physicals were required physicals, whereas personnel not enrolled in these programs were 

offered voluntary physicals. The offering of voluntary physicals may have been withdrawn at a 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

122 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

later date, as the Medical Program had been scoped down to meet the realities of DOE mandates 

and funding levels for the K-25 Medical Program. The minimum requirements established, 

according to more recent guidelines, call for a chest x-ray once every 5 years for workers under 

age 40, and every 3 years after age 40. 

No interviewees could remember having lumber spine x-rays as a screening exam. 

If there were injuries onsite that needed x-rays, they were done onsite. If they needed a 

specialist, they were referred to the Oak Ridge hospital or a private physician. 

HazMat physicals were more intense and required additional medical testing. 

X-rays were also done for asbestos workers and beryllium workers. The schedule for chest xrays for asbestos was as follows: 

• Every 5 years for ages 15–30 

• Every 2 years for ages 35–45 

• Every year after age 45 

One of the interviewees stated that one or two K-25 workers have been diagnosed with 

berylliosis, though he could not remember how that diagnosis was made. B-readers were used 

for backup reading of x-rays for persons on the Asbestos program. ONRL did the LPTs—they 

used both the National Jewish and University of Pennsylvania laboratories. If a worker got a 

positive on his/her LPT, they were sent to a specialist to diagnose for CBD. 

Security guards and Security Inspectors had stress electrocardiogram (EKGs) done routinely. 

The medical department personnel indicated they saw very few contaminated workers – maybe 

1–2 per year. 

One interviewee noted there were reported problems with Tc-99 getting matted in the hair of a 

worker. In this case, they had to use scissors to cut the Tc-99 matted material out of a worker’s 

hair. Medical personnel who needed to decontaminate workers did so in a designated building 

and wore Tyvac suits. Contaminated workers were surveyed prior to and during 

decontamination efforts. 

None of the interviewees could recall the need to treat any skin burns due to exposure to Tc-99. 

Acid burns were not frequent, but did occur rarely. There was one situation where a worker was 

brought in with an irritated eye, due to exposure to hydrogen fluoride. There were also some 

skin irritations from hydrogen fluoride and nitric acid. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

123 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Medical Records 

Chest x-rays taken at K-25, as well as other x-rays for asbestos and respirator fit testing, are 

maintained in charts still stored in K-1007 for current Bechtel Jacobs employees back to 1989. 

This included pre-employment physicals and annual physical exams. 

Medical charts for workers in the 1940s to 1960 may have been microfilmed. After 40 years, 

such medical data can be put into retirement. 

MEDICAL X-RAY PROCEDURES 

General Medical X-ray Policy 

For many years, workers got an annual physical with a chest x-ray. It was a voluntary program, 

but was well received by the K-25 workers. HAZWOPER workers were required to get an 

annual physical. 

Before Bechtel Jacobs took over in 1989, the Medical Department did non-occupational x-rays at 

the request of the worker. It was considered better to keep the worker onsite at his job than to 

send him to his physician offsite. These were always recorded and kept in their records. 

For asbestos and beryllium workers, an initial pre-employment physical was required; and if an 

active worker, an annual physical with chest x-ray each year. If they were inactive workers, they 

got a chest x-ray every 36 months. If they became sensitized to beryllium, they went on a 

different physical examination schedule. The latter was true if they developed CBD. 

Full-face respirator x-rays were done on workers who needed fit testing on an annual basis. 

Some pre-employment examinations were done at Medical Methodist Health Works downtown 

in Oak Ridge to take some of the load off the K-25 Medical Department. Some x-rays were 

done at the Oak Ridge Methodist Medical Center (MMC), particularly if there were serious 

injuries involved. 

At K-25, PA and LAT x-rays were always done. This was also true at ORNL. At Y-12, 

however, they only did a PA film. 

An age test later was recommended. If the worker was less than 45 years of age, he/she received 

a chest x-ray only once every 2 years. After age 45, a chest x-ray was done annually. 

X-rays were taken for other occupational reasons. The K-25 Medical Department did some 

injuries that were thought to be occupationally related. These injuries, however, were few 

(maybe 2 injured/week) and usually involved just fingers, toes, and sprained ankles. If there 

were minor injuries onsite that needed x-rays, they were done onsite. If the injuries were serious, 

the worker was sent to the Oak Ridge Hospital for their x-rays. If they needed a specialist, they 

were referred to the Oak Ridge hospital or a private physician. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

124 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

HazMat physicals were more intense and required additional medical testing. 

Retakes were minimized as much as possible. The retake rate at K-25 was monitored closely 

and was kept at a level that was considered the acceptable norm for the industry. 

Only one patient was allowed in the x-ray room while having the x-ray taken. The technician 

closed the door to the room before taking an x-ray, and she stood behind a lead shield when 

taking the x-ray. 

All chest x-ray films are maintained in the individual’s medical record. 

Calibration of the X-ray Machine 

The HVL for the x-ray machines was measured by a known, licensed, and respected health 

physicist. 

X-ray Machines Used at K-25 

1947–1987: Westinghouse XM Machine with a manual collimator that needed to be set. This 

machine was inspected annually under the FDA contract, until the agreement between FDA and 

DOE dissolved. 

1987 to Present: Bennett D-5251 Unit with a Eureka Tube (Inovision Model 4000) with an 

automatic collimator. X-ray output is 500 mA, but it is run at 300 mA. It was explained that 

300 mA is stronger than 500 mA. 

Both x-ray machines were reported to function well by the K-25 medical x-ray technologist. 

The processor and film developer have continuing maintenance to keep them clean. If the retake 

rate looks abnormal, they would do an additional cleaning prior to taking more x-rays. They 

have an outside contractor come in monthly to clean the processor and film developer. 

Inspection/Certification of the X-ray Machines 

In-house inspections have been done on the x-ray machine being used at K-25 at least since 

1977. A medical health physicist checked the Westinghouse XM machine until 1987. The 

machine was inspected twice a year. They would be provided a report showing the mR readings, 

which were about 17 mR reading in air at 10 mA and 60 kVp, and up to 154 mR mrem/film at 

20 mA and 120 kVp. These values are part of a known, respected, and certified health physicist 

medical x-ray unit Inspector memo to the K-25 medical x-ray department dated April 20, 2006. 

The HP would check their techniques to see if the mR was where it was supposed to be. 

The medical department provided copies of the Radiation Protection Survey of X-ray Equipment 

at ORGDP dated January 3, 1977, and certified by the certified health physicist medical x-ray 

unit Inspector, which indicates that the survey was being done semi-annually. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

125 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

The backup documentation of what was provided during the interviews with the medical 

department personnel is available in a backup PDF file, if needed. 

The surveys, done by a certified health physicist, included a survey of medical x-ray units, 

exposure in air data, and entrance at skin data provided for various x-ray examinations. 

Once a year since 1990, a certified health physicist was brought in as an outside inspector. This 

was necessary, since the HP staff at K-25 was being reduced as a result of the end of production 

of the plant in 1985. 

Retake rates have been inspected since 1985. 

The medical department provided copies of the reports of some of the x-ray unit surveys. 

mm Al used 

The mm of Al used were within specifications. The maximum kVp used was 125 kVp. The mm 

of Al was based on the kVp setting according to the following rule, which was demonstrated on a 

5/9/06 Year 2000 Medical HP Survey Sheet done on the K-25 x-ray machine: 

• 3.0 mm Al - 60 kVp 

• 3.5 mm Al – 80 kVp 

• 4.6 mm Al – 100 kVp 

• 5.8 mm Al – 120 kVp 

After 1985, the x-ray films were looked at even more carefully than in the past. The films were 

now read by a radiologist downtown, and they dictated the retake rate. 

In the mid 1990s, x-rays were also done for asbestos workers and beryllium workers. The 

schedule for chest x-rays for asbestos was as follows: 

• Every 5 years for ages 15–30 

• Every 2 years for ages 35–45 

• Every year after age 45 

NIOSH Visit to the K-25 Site 

NIOSH spent 2 weeks at the K-25 Medical Department complex. “The purpose of their visit was 

to obtain historical information on the medical surveillance program at the site since the early 

1940s.” The information, it is stated, “will be used to help estimate active bone marrow doses 

the workers may have received during routine x-ray examinations of the chest and lower lumbar 

regions during their careers at the site.” They went into the Records Vault in K-1034. They told 

the medical department personnel that they could tell the voltage used and how much the dosage 

was by looking at the x-ray films. They tried to determine if claimants could have gotten a 

higher dose than reported. Their visit is documented in a July 14, 1999, report sent to the 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

126 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Medical department. NIOSH contractors were working on the exposure assessment portion of a 

then-current NIOSH Multiple Myeloma case control study. 

Medical Records 

Chest x-rays taken at K-25, as well as other x-rays for asbestos and respirator fit testing, are 

maintained in charts still stored in K-1007 for current Bechtel Jacobs employees back to 1989. 

This included pre-employment physicals, and annual physical exams. 

Medical charts for workers in the 1940s to 1960 may have been microfilmed. After 40 years, 

such medical data can be put into retirement. 

UNION AND SAFETY CONCERNS 

Union Health and Safety Representatives interface with all levels of workers, managers, health 

and safety professionals, and experts (both internal and external to the site) in industrial safety, 

industrial hygiene, and health physics. 

The Union’s Worker Health Protection Medical Screening Program assists in obtaining medical 

exams for former and current K-25 employees, and with follow-up help with compensation 

claims. Several hundred of these people are eligible for state workers compensation, as well as 

EEOICPA compensation, as a result of their exposures to radiation and toxic substances at K-25. 

Supervisors generally described a “good man” as one who kept his mouth shut around the safety 

people, and did not ask questions! It should be remembered that DOE told their contractors that 

they didn’t want to see incidents; especially involving contamination exposures. The contractors 

made every effort to “clean up” and carefully wordsmith ALL reports going to the DOE. 

COMMUNITY AND HEALTH CONCERNS 

Some interviewees were told that the K-25’s Centrifuge Workers Study reported that the 

incidence of bladder cancer among workers is 7 times higher than the general population. Other 

studies showed 84 cases of Multiple Myeloma, significant increases in lung cancers, nonmalignant diseases of respiratory systems, and cancer of the large intestine. The centrifuge 

workers were supposed to have medical screening for the rest of their lives; but since Lockheed 

Martin is no longer operating K-25, several interviewees felt that DOE has not imposed that 

screening be completed by the new contractor. 

A copy of a July 26, 1945, memorandum (Close 1945) includes a report of concerns by one K-25 

employee that radioactive exposure is the probable culprit of occupational diseases, including 

nephritis, and raised the employee’s concerns of legal implications. 

The interviewees did not remember a K-25 Site employee’s newsletter, but there was an 

employee’s Energy Systems and Union Carbide newsletter that was sent to each K-25 worker’s 

home address. Another interviewee indicated that there is a PDD Daily report, and that there 

were weekly or monthly publications for the employees in the 1980s. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

127 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

An interviewee indicated that she has been supportive in setting up the Coalition for a Healthy 

Environment, the Alliance for Nuclear Workers Advocacy Groups, and the Oak Ridge 

Communities Allied, and has advocated for sick workers. 

During the period of 1999–2004, a contract with the Community Partnership Center at the 

University of Tennessee had existed. Oak Ridge Communities Allied was awarded a technical 

assistance grant by the United States Environmental Protection Agency to study clean-up issues, 

and specifically the re-industrialization program at the K-25 Site in Oak Ridge. About 25 of the 

then K-25 Site workers were interviewed, and an analysis of site documents was completed. The 

completed document was published, but not released, in May 2004. A copy was provided during 

this interview for use by the SC&A K-25 audit team. A reference is cited for this document at 

the end of this interview summary. 

One interviewee noted that at various times, they may have entered areas where workers were 

required to use booties, safety shoes, and safety glasses without PPE equipment being used. 

One interviewee was concerned that they may have been exposed to cyanide at K-25. A group 

of 80 people, both from K-25 and in the community of Oak Ridge, similarly felt that they had 

suffered potential cyanide poisoning and were the instrumental group that formed the Coalition 

for a Healthy Environment. All of them reported high urine thiocyanate levels during the period 

of 1995–1996. 

In 1995 at K-25, a sewer relining project was underway that used a hot blast of air to cause the 

lining to adhere to the walls of the old sewer. This process caused a cyanide gas compound to be 

released into the atmosphere. Upon request from the workers, NIOSH came to perform a Health 

Hazard Evaluation (HHE). K-25 Plant Management had new radiation signs erected to preclude 

anyone from going into certain areas. Hence, NIOSH was prohibited from performing a 

complete investigation. The University of Alabama was brought in to review the situation and 

found the HHE lacking. 

It was noted that according to a report completed by the PACE union, that in K-1037, there is a 

high risk of exposure to nickel and mercury. Also, because of the development work on circuit 

boards in K-1037, there could have been exposures to gallium. An interviewee also reports 

exposure to gadolinium. 

Radiological Exposure 

One interviewee recalls a situation where they turned off the monitors for the TSCA incinerator 

because the alarms had been going off too frequently. In the early years, workers were not 

monitored consistently (mostly external doses) and workers were never monitored for exposures 

to anything but radiation. 

An interviewee recalled that after 1992, some workers who were not wearing PPE, went into 

sites where pollution prevention projects were underway. When the interviewee was on the site, 

it was customary to use just booties, eye protection, a hard hat, and safety shoes. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

128 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

At ORNL, an interviewee saw workers loading low-level waste into containers, and those 

watching were not wearing PPE. 

Radiation Monitoring 

One interviewee indicated they did have a TLD badge, but stated that it was only changed once a 

year. The interviewee stated that they did go into the cylinder yards and the fluorination areas, 

where there is a potential for high gamma dose. They were instructed to wear their dosimeter 

above the waist. It was reported that they received an annual dose report that always showed 

“zero” exposure to any radiation. The interviewee never had a respirator assigned. 

An interviewee reported that they did have change rooms and showers in K-1037. They were 

allowed to eat, drink, and smoke in the kitchen, and anywhere in K-1037 or the entire site. 

One interviewee noted that they had no training in HAZWOPER or radiation safety. They 

reported that they only had the TLD changed annually while at K-25. 

Environmental Characterization 

From 1994 to 1996, a great deal of environmental characterization occurred at the K-25 Site. 

They used dye in wells to trace the flow of groundwater contamination. 

Worker Death 

There was one fatality on the K-25 Site that involved a foreman who insisted on doing a job 

himself, realizing that it was a hazardous situation. He was working on a rack during lunchtime 

and fell to his death. 

SECURITY 

Security Policemen (SP) at K-25 were responsible for the physical protection of the entire 

facility. SPs were responsible for protecting sensitive and classified assets, including assignment 

to close in patrols and verification of integrity. This required the physical presence of the SP at 

the asset location, which potentially exposed SPs to hazards associated with the location. The 

responsibility of the job required access all around the K-25 facility (e.g., process buildings, 

laboratories, dump sites, incinerators, support buildings, and areas immediately surrounding the 

site). SPs at K-25 worked on a rotating shift basis, along with a rotating assignment schedule. 

Tactical drills often required that SPs go into areas not normally occupied by employees (e.g., 

the pipe gallery). These areas were not known to be decontaminated prior to entry. SPs entered 

these areas to get the best line of site view for the exercises. SPs from K-25 were often assigned 

to drills conducted at Y-12 and X-10. 

There was a common firing range used by security personnel from X-10, Y-12, and K-25 on 

Bear Creek Road. Among the activities that took place at the range was the purging and blowing 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

129 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

up of discarded UF6 cylinders. There was also a burial site at this general location. Duratek, a 

private entity, also operates a Hazardous Waste Processing Area adjacent to the range. 

Security personnel were often called upon to respond to emergencies and incidents at the facility 

and around the site. They provided asset protection when necessary, traffic control, and people 

control during this time. During the initial response phase, SP were often very close to the 

incident. 

Security personnel also routinely visited other DOE sites while on special assignments. For 

example, if a guard union went on strike at one DOE site, K-25 security staff may be relocated to 

replace the striking staff. Some of the sites visited by those interviewed included Y-12, X-10, 

RFP, Hanford, Nevada Test Site (NTS), Paducah, Portsmouth, Sandia, and Pinellas. These 

assignments could last a few days up to months. While on temporary assignment, they 

essentially performed the duties similar to their regular duties at these sites. Some security 

personnel worked with subcontractors prior to being hired by the site contractor (Union Carbide). 

There was no requirement for frisking in and out of areas prior to the 1990s. The site was not 

managed to control the spread of contamination. For decades, when workers, including SP, had 

a need to leave a hazardous work zone, they simply left without any controls in place, thereby 

creating the possibility of spreading contamination into support areas of the plant, such as the 

cafeteria, medical, and administrative areas. As a result, administrative workers were often also 

exposed to the same hazards to which the process workers were exposed. 

SPs were required to wear uniforms in order to have access to weapons and to be allowed 

unrestricted movement capabilities. There were some areas where SPs only wore their uniforms, 

while other workers were required to wear protective clothing. For decades, SPs changed into 

their street clothes while storing their contaminated uniforms in the same locker. If not soiled, 

uniforms may be reused for multiple shifts. Many wore contaminated shoes home. Showers 

were optional for SPs at the end of the shift. 

Prior to the mid-1990s, there was some random urine sampling provided for Security personnel. 

For other non-security workers, bioassay could be collected as frequently as weekly. One 

individual recalls submitting a urine sample after banging his head while responding to an alarm 

in a radiological area. He was told to drink plenty of water and come back in 1 week for reanalysis. 

Those SPs interviewed received only a single-body count during their entire time at K-25. 

Dosimeters were assigned to patrol. However, the Security personnel believe that only some 

badges were processed for those workers defined by Health Physics to be the most exposed 

workers (e.g., K-1420 personnel). Security personnel felt their badges were selected and read on 

a random basis. 

The PPE has changed over time at K-25. Personnel originally used half-face respirators, which 

were carried into the process areas in a duty bag. Respirators were reused more than once. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

130 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Filters were not always approved for the contaminants to which they were potentially exposed. 

Full-face respirators were also used for some jobs. 

One of the interviewees indicated he noted an absence of 10 years of dosimetry records in his 

individual dosimetry file. 

SAFETY HAZARDS 

K-25 was involved in several activities that exposed workers to chemical hazards. 

Trichloroethylene (TCE) and rags were used as a cleaning agent. Although the workers wore 

gloves, they were not effective at keeping the TCE from getting on the skin. 

Maintenance personnel were exposed to beryllium while grinding the metal. 

MFL oil was used in Building K-413 to trap contaminants, because of its high density and 

consistency. The use of this oil resulted in evacuations of specific buildings as frequently as 

daily for a period of time. 

The acids used in K-1131 caused etching in the building’s windows. 

K-1413 was involved in experimental work using a wide variety of chemicals. Some of the work 

was done for X-10. 

There were incidents associated with the internal portion of the fluorine generators exploding. 

This required that the internal portion of the unit be removed and reworked. 

Other hazardous chemicals found at K-25 include mercury, asbestos, picric acid, motor oils, 

Hexavalent Chromium, PCBs, dioxins, and acids, to name a few. Biological hazards were 

identified in cooling water. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

131 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

REFERENCES PROVIDED OR CITED BY THE INTERVIEWEES 

Alvarez, Robert. 2000. A Review of the Health And Mortality Experience of U. S. Department 

of Energy Workers. The Government Accountability Project. January 2000. [Selected Pages 

only] 

BJC (Bechtel Jacobs LLC). 2000. Oak Ridge Gaseous Diffusion Plant Mass Balance Project. 

[No title page was provided] Bechtel Jacobs Company, 2000. 

BJC (Bechtel Jacobs LLC), Environmental Baseline Survey Report for the Title Transfer of K1007 Building at the ETTP, BJC/OR-1236/R1. 

Chem Risk. 1993. Report on off-site emissions is a report entitled “Oak Ridge Health Studies, 

Phase I, Feasibility Study, A Summary of Historical Activities on the Oak Ridge Reservation” 

published in April 1993. This includes information concerning off-site emissions of hazardous 

materials. It was published by Chem Risk (A Division of McLaren and Hart). It can be ordered 

by writing to 113 Atlanta Avenue, Alameda. California, 94501. 

ChemRisk. 2000. Oak Ridge Dose Reconstruction Project Summary Report. Reports of the 

Oak Ridge Dose Reconstruction, Vol. 7. Submitted to the Tennessee Department of Health. 

March 2000. [Selected Pages only] 

Close, Philip J. 1945. Determination of Policy on Gases of Exposure to Occupational Disease. 

A memo to Major G. A Tamey, Jr. Army Service Forces, United States Engineer Office, 

Manhattan District, Oak Ridge, Tennessee. July 26, 1945. 

Clouse, R. J. 1963a. May Inspection of K-1302 Vent Stack. A Union Carbide Nuclear Company 

Memorandum to R. L. Newton on June 4, 1963. 

Clouse, R. J. 1963b. K-1302 Vent Stack Cleaning. Union Carbide Nuclear Company 

Memorandum to W. H. Taylor on November 11, 1963. 

Clouse, R. J. 1963c. K-1302 Vent Stack North Fan Housing. Union Carbide Nuclear Company 

Memorandum to W. H. Taylor on November 13, 1963. 

Consort Technologies sampling report. 

DOE 1997. Declassification of Today’s Highly Enriched Uranium Inventories at the Portsmouth 

Gaseous Diffusion Plant in Portsmouth, Ohio and the K-25 Site in Oak Ridge, Tennessee. U. S. 

Department of Energy, Office of the Press Secretary, Washington, DC 20585. January 30, 1997. 

DOE 2000a. Independent Investigation of the East Tennessee Technology Park, Volume 1: Past 

Environment, Safety, and Health Practices. DOE Office of Oversight, Environment, Safety and 

Health. October 2000. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

132 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DOE 2000b. Independent Investigation of the East Tennessee Technology Park, Volume 2: 

Current Environment, safety, and Health Programs and Issues. DOE Office of Oversight, 

Environment, Safety and Health. October 2000. 

Dixon, J. W., and S. S. Stief. 1958. K-1131 Material Release, Report No. 271. Union Carbide 

Nuclear Company Memorandum to J. A. Parsons on September 18, 1958. 

EH Investigation of the Uranium Recycle Program. 

Former Worker Medical Surveillance Program at the Department of Energy Gaseous Diffusion 

Plants: Needs Assessments. 

Griffon, Mark, and Michael Ellenbecker. 1997, Preliminary Exposure Assessment for the 

Former Workers at the DOE Gaseous Diffusion Facilities (Oak Ridge K-25, Portsmouth, and 

Paducah). University of Massachusetts Lowel, Work Environment Department. September 

1997. 

Goddard, P. L., A. J. Legeay, D. S. Pesce, and A. M. Stanley. 1991. Site Descriptions of 

Environmental Restoration Units at the Oak Ridge K-25 Site, Oak Ridge, Tennessee. Prepared 

for U. S. Department of Energy, K/ER-47. October 1991. [Selected Pages only] 

Hilsmeier, W.F., Supplementary Meteorological Data for Oak Ridge, Report ORO-199, U.S. 

Atomic Energy Commission, Oak Ridge Operations. 

Jarabek, R. J., and P. E. Osborne. 1989. The Chemical Inventory for Materials and Chemistry 

Technology Department. Oak Ridge Gaseous Diffusion Plant, Martin Marietta Energy Systems, 

K/QT-320. October 1989. 

Kaplan, Susan. 2001. Hold Government Responsible For Worker Health Care Needs. Source: 

http://www.oakridger.com. October 4, 2001. 

Lawson, Bruce. [undated]. Report for Dr. Michaels. Former Pace Local 5-288 Health and 

Safety Representative. 

Listing of Facilities on the 1993 Consort Technologies document (K/HS-570). 

Michaels, David, 2000, Independent Investigation of the ETTP, Volume 1: Past Environmental, 

Safety and Health Practices, Office of Oversight, Department of Energy, October 2000. 

Miller, Richard. 2006. The Energy Employees Occupational Illness Compensation Program 

Act: Are We Fulfilling the Promise We Made to these Veterans of the Cold War When We 

Created the Program? Testimony to the Government Accountability Project, Committee of 

Judiciary, U. S. House of Representatives, Oversight Hearing 4. November 15, 2006. 

MMES Radiological Control Operations Manual. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

133 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Mynatt, Fred R. 1991. Worker Radiation Exposure Data Used for Epidemiological Studies. A 

letter to D. L. Cragle, Director of the Center for Epidemiological Research, Oak Ridge 

Associated Universities, Oak Ridge, Tennessee. Martin Marietta Energy Systems, Inc. October 

11, 1991. 

Proposed Transfer of Buildings K-1007, K-1225, K-1330, K-1400, and K-1580 at the ETTP, Oak 

Ridge, Tennessee, January 15, 2004. 

Reed, W. R. 1988. ORGDP Diffusion Facilities Permanent Shutdown. Engineering Feasibility 

Study/Site Characterization. March 3, 1988. [Selected Pages only] 

Soil Vapor Results for the Winter Sampling for Building K-1007 at the ETTP. 

Smith, R. F. 1984. Historical Impact of Reactor Tails on the Paducah Cascade. Paducah 

Gaseous Diffusion Plant, Union Carbide Report KY/L-1239. [One page only]. 

Tetra Tech, Inc. 2004. Limited Characterization Plan for the Main Plant Phase II Facilities, 

East Tennessee Technology Park, Oak Ridge, Tennessee. Bechtel Jacobs Company LLC, 

BJC/OR-1384 (DRAFT). May 2004. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

134 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

ATTACHMENT 3: KEY QUESTIONS AND RESPONSES FOR 

NIOSH/ORAU REGARDING SITE PROFILE DOCUMENTS 

SC&A submitted questions related to the K-25 Site Profile Documents to NIOSH on November 

9, 2006. The NIOSH/ORAU team provided written responses to these questions on December 

13, 2006. Both the questions and responses have been provided below. A summary of the 

conference call conducted between SC&A and the NIOSH/ORAU team with regard to these 

questions is available in Attachment 4. 

Responses to SC&A Questions for the K-25 Site Profile Document – 

Introduction TBD, ORAUT-TKBS-0009-1 

Site Description TBD, ORAUT-TKBS-0009-2 

Occupational Medical Dose TBD, ORAUT-TKBS-0009-3 

Occupational Environmental Dose TBD, ORAUT-TKBS-0009-4 

Occupational Internal Dose TBD, ORAUT-TKBS-0009-5 

Occupational External Dose TBD, ORAUT-TKBS-0009-6 

Planned revisions of these documents will include additional information collected since the 

publication of this TBD and any applicable information that comes from NIOSH responses to 

SC&A questions. 

ORAUT Answers to Key Questions 

Regarding the K-25 Site Profile 

December 13, 2006
 

[Questions submitted by the SC&A review team, November 9, 2006] 

GENERAL QUESTIONS 

(1) Please clarify when dose from the Naval Nuclear Propulsion Program is included in a 

dose reconstruction. For example, would the following be included: 

(a) DOE employees working on NNPP tasks; 

(b) Non-DOE employees working on a DOE site on NNPP tasks; 

(c) Subcontractor employee working on a DOE site on NNPP tasks. 

Response - 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 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

135 of 191 

 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

the Naval Nuclear Propulsion Program. As a result, all internal and external dosimetry 

monitoring results are considered valid for use in dose reconstruction. 

(2) Were classified records considered in the site profile development? If so, what were 

these documents? 

Response - No classified documents were reviewed prior to the development of the K-25 

Site Profile. 

(3) Is there a classified version of the site profile? 

Response - No, a classified version of the Site Profile was not developed. 

(4) In general, what areas could not be included in the TBD for National Security Reasons? 

How were these compensated for in the TBD? 

Response - Specific procedures and descriptions of process equipment were not available 

for review in unclassified documents. Details about the separation of uranium isotopes 

and the equipment used to enrich uranium 235 were not available to develop the Site 

Profile. However, personnel exposure to ionizing radiation, both internal and external 

exposure, was documented using the technology and criteria approved for that period of 

time. There was sufficient information to establish radiation exposures for personnel 

working with classified materials. The current Site Profile addresses what is believed to 

be the major contributors to exposure, but as additional information becomes available 

and modifications are warranted, the Site Profile will be revised. 

(5) Is any of the work history, medical or radiation exposure data for claimants classified? 

Are claimant files being redacted for national security reasons? 

Response – We are not aware of any claim files that are classified or being redacted for 

national security reasons. 

(6) The TBDs have mentioned several times that the TBD has addressed Worker Outreach 

comments. Please provide SC&A with the contents and respective NIOSH responses. 

Response – These are located in Attachment A. 

(7) Which TIBs are used to supplement the TBDs in the dose reconstruction process? 

OTIB-0002, Maximum Internal Dose Estimates for Certain DOE Complex Claims 

OTIB-0018, Internal Dose Overestimates for Facilities for Air Sampling Programs 

OTIB-0020, Use of Coworker Dosimetry Data for External Dose Assignment, 2004. 

OTIB-0035, Internal Dosimetry Coworker Data for K-25, 2005. 

OTIB-0026, External Dosimetry Coworker Data for the K-25 Site, 2006. 

OTIB-0052, Parameters to Consider When Processing Claims for Construction Trade 

Workers, 2006.
 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

136 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

(8) With whom did NIOSH conduct site expert interviews during the development of the site 

profile? Please provide the names of individuals. 

Response – Contributions on internal dosimetry, external dosimetry, and medical 

exposures were incorporated based on discussions with current and former staff. These 

contributions are referenced in the Site Profile. 

(9) What types of claims have been evaluated to date? Without a complete dataset, how is 

NIOSH/ORAU sure the doses are bounded? 

Response – Cases with both monitored and unmonitored workers have been evaluated 

with numerous cancer types. The analysis performed to generate OTIB-0026, OTIB-0035 

and OTIB-0052 support that the doses are bounded. 

(10) How has NIOSH/ORAU verified the completeness and accuracy of the data provided by 

K-25 Site? 

Response - The Site Profile was developed using documents that were developed by K-25 

and reviewed by the DOE. When available, multiple documents were referenced to 

provide consistency. 

(11) How have you integrated site expert input into the TBD? 

Response – Contributions on internal dosimetry, external dosimetry, and medical 

exposures were incorporated based on discussions with current staff. These contributions 

are referenced in the Site Profile. 

SITE DESCRIPTION (ORAUT-TKBS-0009-2) 

(1) Explain why the Site Description did not address the cascade improvement efforts at K25. 

Response – From review of the available literature it appears that the cascade 

improvement efforts continued over much of the operating life of the K-25 facility. It 

appears that these efforts were part of the ongoing activities at the site. If significant 

events within the cascade improvement effort are identified which have the effect of 

causing significant unmonitored dose which isn’t otherwise addressed by the site profile, 

it will be included in a document revision. 

(2) Has NIOSH identified any special projects or facilities that handled other radionuclides 

than those handled in the uranium enrichment and recycling processes? 

Response - Other projects were mentioned in Worker Outreach meetings. However, no 

definitive documentation was found during data capture to detail other activities. It is 

assumed that uranium was the primary source of exposure. Impurities in recycled 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

137 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

uranium are also addressed, and a Tc-99 campaign was included in the internal dose 

coworker OTIB. 

(3) NIOSH discusses the U:TRU activity ratios in several sections. Is this referring to the 

total TRU activity or that of a specific TRU radionuclide? If this is total TRU activity, 

NIOSH ought to identify which TRU radionuclides make up this group. 

Response – Section 5, Occupational Internal Dose, Table 5-6 lists the default isotopic 

distribution. 

(4) Should NIOSH be identifying 242Pu as one of the TRU radionuclides in the facility? 

Response - Pu-242 is identified as being present at K-25 in Table 5-5 of ORAUT-TKBS0009-5. 

(5)	 242/244Cm are listed in Table 2-1, but not discussed as being in any of the facilities 

discussed. Please explain. 

Response – Although reference to 242/244Cm was not found specifically in the documents 

researched for K-25, it is a contaminant of recycled uranium. It is provided in the table to 

give the dose reconstructor an assumed solubility type if it is referenced in a worker’s 

records. 

OCCUPATIONAL MEDICAL DOSE (ORAUT-TKBS-0009-3) 

(1) What type of special medical chest x-ray examinations have been documented in the 

individual medical record and are included in the K-25 worker’s occupational medical 

dose? 

Response - No special medical X-ray examinations have been noted in the individual 

medical records for K-25. Per 42 CFR 81 and 82, the only occupational medical dose 

eligible to be included in dose reconstruction under EEOICPA is dose from x-rays that 

were required of employees, as part of medical screening and surveillance programs. The 

Occupational Medical TBD addresses organ dose from these procedures, and these 

procedures only, as prescribed by 42 CFR 81 and 82. 

(2) If the individual medical record and CATI do have specific information on the frequency, 

reasons for and type chest x-ray, how is NIOSH/ORAU handling the assignment of dose 

when it is evident that these types of chest x-rays were commonly being given? 

Response - [The responder infers that “do NOT have” is meant in the first line of this 

question.] 

Section 3.2 in the TBD states, “The reconstruction of occupational dose should include 

all occupational X-rays according to the frequency listed in Table 3-1 unless the 

individual-specific frequency is known and is more frequent than that in Table 3-1.” This 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

138 of 191 

 

 

 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

is the approach taken when a dose reconstructor uses an "overestimate" approach in the 

dose reconstruction. When a "best estimate" approach to the dose reconstruction is 

necessary, the actual x-ray records are requested from K-25, if not already provided, and 

used for X-ray dose assignment. K-25 has been responsive to such requests. These 

approaches are documented in Procedure 61, Occupational X-ray Dose Reconstruction 

for DOE Sites. 

(3) Did worker’s have dose estimates in their medical records for chest x-rays taken for 

respiratory protection, beryllium work, asbestos work, food handling and, radiographic 

operations? 

Response - No dose estimates from X-rays are included in the records provided by the 

K-25. 

(4) Table 3.1-2 (Turner 2004 – pg. 9) indicates that during the period from 1944 to 1945 

some uranium dust workers were getting chest x-rays monthly and during the period from 

1946 to 1959 every few months. What is the default number (i.e., 12) for uranium dust 

workers when there is no evidence in their medical record that this many chest x-rays 

were given. Likewise, how is NIOSH handling chest x-rays every few months for those 

uranium dust workers from 1946 to 1949? 

Response - [The responder believes that the question refers to Table 3-1 (not 3.1-2) at 

the beginning and to 1959 (not 1949) at the end.] 

Section 3.2 in the TBD states, “The reconstruction of occupational dose should include 

all occupational X-rays according to the frequency listed in Table 3-1 unless the 

individual-specific frequency is known and is more frequent than that in Table 3-1.” K-25 

usually provides the actual x-ray records with the individual dosimetry data. The dose 

reconstructor assigns dose from the X-ray examinations found in the medical records. If 

the actual records indicate that monthly X-rays were not provided, then dose from 

monthly exams is not assigned. 

(5) How is NIOSH/ORAU assigning dose for K-25 workers who worked with uranium dust? 

How are these uranium dust workers differentiated from other workers to ascertain 

whether to assign annual or more frequent x-rays? 

Response - This response addresses only the medical dose for uranium dust workers. 

Because there has been no indication in the medical records of X-rays provided on a 

monthly basis, an assumption has been made to assign X-rays on an annual basis and to 

request actual records when there is a question as to the appropriate X-ray frequency. As 

mentioned previously, K-25 usually provides the actual x-ray records with the individual 

dosimetry data, and they are responsive to requests to provide it, in case they did not to 

begin with. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

139 of 191 

 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

(6) If some workers received more chest x-rays than Table 3.1-1 (Turner 2004 – pg. 9), how 

is this being determined? Is there any other evidence of frequency other than the 

individual medical record and the CATI and are such workers assigned dose for these 

more frequent x-rays? 

Response - There is no documentation or other indication that chest X- rays were given 

more often than according to the frequencies shown in Table 3-1. In any case, doses 

would be included for all such examinations shown in an individual’s medical or other 

personal records. 

(7) The Occupational Medical Dose TBD (Turner 2004 – pg. 4) states that “...chest x-rays 

were no longer required for non-radiation workers after 1950...” Have the individual 

medical records of non radiation workers been reviewed to validate this? 

Response - In the citation, the year is 1959, rather than 1950. This has not been 

validated; however, a claimant favorable approach has been used to assign annual 

X-rays unless the actual records indicate a lesser frequency. 

(8) The Occupational Medical Dose TBD (Turner 2004 – pg. 5) states that “The K-25 site 

used only the conventional PA chest X-ray technique for routine examinations after the 

early 1950s...” Up until what time are K-25 workers, who received PFG exams, being 

assigned the higher dose associated with PFG examinations? 

Response - See response to item 10, below. Until the end of 1956, the higher PFG doses 

are to be assigned in the absence of information to the contrary. As evident from 

Table 3-3, the organ doses for PFG examinations are considerably higher than the other 

values. 

(9) Will subsequent updates of the K-25 Site Occupational Medical Dose TBD incorporate 

the additional new information in OTIB-0006 (Kathren and Shockley 2005) and will the 

3.0 rem/PFG exam be utilized in determining dose for K-25 workers in the period up to 

the early 1950s? 

Response - In effect, for the pre-1970 time period, the TBD is almost entirely consistent 

with OTIB-0006 (Kathren and Shockley), which was available and consulted in advanced 

draft form prior to its issuance. The site specific documented skin entrance kerma, 

2.488 cGy, for the K-25 PFG exams (Table 3.2-1) was utilized in the TBD rather than the 

generic default value 3.0 cGy from OTIB-0006. (ORAUT-OTIB 0006 was developed to 

provide default values for entrance kerma and organ doses when specific X-ray machine 

data from a site was either not available or suspect.) 

(10) The Occupational Medical Dose TBD (Turner 2004 – pg. 7) states that “The type of Xray machine was probably recorded, so organ dose can be extracted directly from Table 

3.3-1.” Has the NIOSH/ORAU review of the claimant’s individual medical record 

documented that this is indeed the case and if not, what other documentation has been 

found to establish this? 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

140 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Response - As stated in the TBD along with the above quotation, Cardarelli (2002) 

estimates that, from 1944 to 1956, when both machines were in use, 86% of the 

examinations were performed with GE KX-10 PFG exposures. If the medical record does 

not identify which machine was used, the claimant-favorable assumption would be that it 

was the GE KX-10. This is consistent with a recommendation given (p. 18) in Winslow 

2006 (ORAUT-PROC-0061). In most cases, the individual medical records do not 

include the information to ascertain the type of X-ray machine used, and the latest 

revision of the TBD (2006) does not contain the statement quoted above. 

(11) How is NIOSH/ORAU handling the assignment of dose for upper GI fluoroscopy and 

lumbar spines done on some K-25 workers? 

Response - Per 42 CFR 81 and 82, the only occupational medical dose eligible to be 

included in dose reconstruction under EEOICPA is dose from x-rays that were required 

of employees, as part of medical screening and surveillance programs. The Occupational 

Medical TBD addresses organ dose from these procedures, and these procedures only, as 

prescribed by 42 CFR 81 and 82. 

Evidence has not been found to indicate that upper GI (UGI) fluoroscopy exams were 

performed for medical screening at K-25, nor does the relative infrequent occurrence of 

UGI exams in the K-25 worker records support the indication that UGI fluoroscopy was 

used for medical screening. Lumbar spine exams, however, are well known to have been 

performed for medical screening of certain groups of workers, and OTIB-0006 provides 

guidance for the assignment of lumbar spine doses, should they be indicated in the 

workers' medical record to have been performed for medical screening (i.e. not for work 

related or personal injury). 

(12) As noted in the discussions with NIOSH/ORAU regarding ORNL workers, does 

NIOSH/ORAU still plan to limit occupational medical exposure to pre-employment, 

annual, health monitoring examinations and termination chest x-ray examinations except 

for some lumbar spine examinations in the 1950 to 1953 timeframe and to include all 

other exposures (including screening examinations) as part of worker non-occupational 

medical dose? 

Response - Per 42 CFR 81 and 82, the only occupational medical dose eligible to be 

included in dose reconstruction under EEOICPA is dose from x-rays that were required 

of employees, as part of medical screening and surveillance programs. The Occupational 

Medical TBD addresses organ dose from these procedures, and these procedures only, as 

prescribed by 42 CFR 81 and 82. 

(13) Can NIOSH/ORAU provide more definitive information to establish beam quality for xray units used for K-25 worker chest x-rays? 

Response - Beam-quality assignments in the TBD are probably reasonable, especially for 

later times. As pointed out above (question 9), the pre-1970 organ doses are close to the 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

141 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

claimant-favorable default values in OTIB-0006. Beam quality appears to be adequately 

established. 

(14) Has NIOSH/ORAU been able to find documentation to support the assumed techniques 

and protocols applied to calculate the dose for K-25, which is mainly derived, in general, 

from ICRP Publication 34 (ICRP 1982)? 

Response - Use of the dose conversion factors (DCFs) in ICRP Publication 34 (ICRP 

1982) is a widely accepted method of x-ray dosimetry, once entrance kerma and half 

value layer are known or can be reasonably estimated. NIOSH has used "substitute" 

DCFs from ICRP Publication 34 (ICRP 1982) in some circumstances when it can be 

reasonably postulated that actual conditions at DOE sites were such that substitute DCFs 

were warranted. For example, it can be reasonably postulated that x-ray beams prior to 

about 1970 were not as well collimated as the beams in 1982 when ICRP Publication 34 

(ICRP 1982) was published, meaning that additional organs were likely to have been 

irradiated in a poorly collimated x-ray beam. The K-25 TBD and OTIB 0006 both 

assume a poorly collimated beam prior to 1970, and use substitute DCFs to account for 

this. The substitute dose conversion factors are chosen (and documented in ORAUTOTIB 0006, 2003 and 2005) to include more organs in the primary beam than would be 

the case for a properly collimated beam. 

OCCUPATIONAL ENVIRONMENTAL DOSE (ORAUT-TKBS-0009-4) 

(1) The K-25 Occupational Environmental Dose TBD (East 2006, pg. 7, Section 4.2, Internal 

Dose from Onsite Atmospheric Radionuclide Concentrations) states the following. 

...Unmonitored workers can be exposed to occupational doses internally from 

onsite releases to the air and from the resuspension of radioactive materials 

in soil, and externally from ambient radiation and releases of radioactive 

noble gases to the air. 

There is no other mention of noble gases elsewhere in the TBD. Is this a generic 

statement or has NIOSH/ORAU identified radioactive noble gases that may have 

contributed to the external dose of unmonitored workers? 

Response - There was a potential for the presence of noble gases released after the 

processing of recycled uranium. The exposures that were evaluated in Chapter 5 of the 

K-25 TBD were associated with the presence of transuranics, including neptunium and 

plutonium and mixed fission products including technetium. There was no specific 

evaluation of noble gases rather the pathway for exposure from noble gases was external 

radiation and the assignment of external exposure to unmonitored workers. External 

exposure to monitored workers was evaluated using the external dosimetry available in 

the claim files. 

(2) The K-25 Occupational Environmental Dose TBD (East 2006, pg. 7, Section 4.2.1, 

Onsite Release to Air) states: 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

142 of 191 

 

 

 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

...A calculation was performed using well-documented source terms 

developed for the Oak Ridge Dose Reconstruction (ORDR) (Burmeister 1996, 

1997, Burns 1997), coupled with some 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 the majority of the potential missed dose from 

inhalation and submersion pathways. 

By comparison, the K-25 Site Description TBD (Szalinski 2006, pg. 7, Section 2.2, Site 

Activities and Processes) states 

...Process operations primarily resulted in 234U, 235U, and 238U 

contamination. Characterization of the recycled uranium included in the 

Recycled Uranium Mass Balance Project Oak Ridge Gaseous Diffusion Plant 

Site Report indicate the primary contaminants incident to the recycled 

uranium are technetium-99 (99Tc), neptunium-237 (237Np), americium-241 

(

241Am), plutonium-238 (238Pu), 239/240Pu. 

Has NIOSH/ORAU considered including 241Am as a contaminant of concern for potential 

missed dose? 

Response - As described in Chapter 5 of the K-25 TBD, the potential exposure to various 

isotopes in recycled uranium were evaluated. While several isotopes were potentially 

present, the major contribution to radiation dose was associated with plutonium and 

neptunium. The current TBD addressed what is believed to be the major contributors to 

exposure, but as additional information becomes available and if it indicates 

modifications are warranted, the TBD will be revised. 

(3) The air concentrations used to calculate annual intakes for the included contaminants of 

concern are provided at the 50th percentile. By comparison, the K-25 sister facility 

(PGDP) has provided maximum reported air concentrations to calculate annual intakes. 

Has NIOSH/ORAU considered the difference in these two approaches? Is the use of the 

50th percentile air concentration values claimant favorable? 

Response- The environmental data provided in the K-25 TBD were derived source terms 

calculated for the Oak Ridge Dose Reconstruction (ORDR) by Burns and Shonka. Results 

from the air monitoring stations were modified to account for dilution and an estimate of 

maximum ground concentrations. In short, the use of the 50th percentile result is 

considered to be a claimant favorable approach given the modifications required to 

convert the data into a useful representation of potential radiation dose. In contrast, the 

results at PGDP required fewer modifications and were considered to be more 

representative of potential exposure to unmonitored workers. The current TBD addressed 

what is believed to be the major contributors to exposure, but as additional information 

becomes available and if it indicates modifications are warranted, the TBD will be 

revised. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

143 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

(4) Is there any wind study data (wind rose) to support the use of the environmental monitors 

chosen for maximum ground level concentrations? Where is the administrative area 

(Figure 4-1, pg. 8) in relation to the identified release points? 

Response - There was no wind study data available at the time of the development of the 

environmental dose for the K-25 TBD. The current TBD addressed what is believed to be 

the major contributors to exposure, but as additional information becomes available and 

if it indicates modifications are warranted, the TBD will be revised. 

The administrative area was a significant distance (more than 2,000 meters away) from 

the air monitoring stations depicted in Figure 4-1. For that reason, the results from the 

monitoring stations were modified to address potential dilution and estimate the 

maximum ground level concentrations. A description of the modifications is provided in 

Section 4.2.1 of Chapter 4 of the TBD. 

(5) The K-25 Occupational Environmental Dose TBD (East 2006, pg. 8, Section 4.2.1, 

Onsite Releases to Air) states: 

...To provide a conservative estimate, environmental monitors were chosen 

that were adjacent to the K-25 Site and generally located in upwind and 

downwind locations relative to release points. These were where maximum 

ground level concentrations from the site would occur. 

Has NIOSH/ORAU considered that an upwind location would provide release data and 

ground-level concentrations that are lower than those observed at the downwind location 

and not be conservative or claimant favorable? 

Response - It is not clear that this potential situation has been considered. This TBD 

should be revised to clarify that the downwind sampling locations be given primary 

consideration when determining environmental occupational dose. Also, given the new 

documents that are available for K-25, it may be appropriate to update this chapter. 

The current TBD addressed what is believed to be the major contributors to exposure, 

but as additional information becomes available and if it indicates modifications are 

warranted, the TBD will be revised. 

(6) Has NIOSH/ORAU taken into consideration acute or episodic releases (other than 

uniform releases) that might contribute to missed internal or external dose of the 

unmonitored worker? 

Response - No. As described in Section 4.2.1, source terms were established using the 

reports published by the ORDR in 1997. The current TBD addressed what is believed to 

be the major contributors to exposure, but as additional information becomes available 

and if it indicates modifications are warranted, the TBD will be revised. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

144 of 191 

 

 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

(7) The K-25 Occupational Environmental Dose TBD (East 2006, pg. 11, Section 4.3.1, 

Ambient Radiation) states: 

...The ORR Annual Environmental Report for 2003 (DOE 2004) reports a 

dose from the K-25 cylinder yards to a nearby parking area at 4.75 

mrem/125h (75 mrem/200h). 

Has NIOSH/ORAU considered that doses received by unmonitored workers working 

near the cylinder yards would be potentially higher than doses measured in the parking 

area? 

Response – Access to the cylinder storage yards was limited and the parking lot 

represents the closest location where unmonitored workers may visit. Workers assigned 

to work in the cylinder storage yard were monitored. For the purposes of unmonitored 

workers, the exposure in the parking lot is a claimant favorable assumption. 

(8) The K-25 Occupational Environmental Dose TBD (East 2006, pg. 11, Section 4.3.1, 

Ambient Radiation) states: 

...Uranium cylinder storage yards remain the only significant source of 

external exposure at K-25. Surveys in cylinder yards at the sister plants show 

dose rates up to 200 mrem/2000h. 

The PGDP Occupational Environmental Dose TBD (East 2006, pg.12, Section 4.3 

External Dose) states: 

...Unmonitored workers in the early years did not have significant inventories 

of depleted uranium to contribute to external dose. Later, unmonitored 

workers would not spend their entire work year at the depleted cylinder yards 

and, therefore, would not reach the maximum dose recorded by fence line 

monitoring. No other significant sources of external exposure are associated 

with the PGDP operations. An assumed deep dose equivalent rate of 200 

mrem/yr for all years would be reasonable, and deficiencies in earlier 

measurement techniques thereby become immaterial. 

The recommended 200 mrem/2000h for PGDP is quoted yet 75 mrem/2000h is used as 

the recommended external dose from the uranium cylinder yards for K-25. Has 

NIOSH/ORAU considered the difference in these two approaches? Is the use of the 

75 mrem/2000h claimant favorable? 

Response - The assumptions for potential external exposures at PGDP may not be 

applicable to the potential exposures at K-25. It is not clear that this potential situation 

has been considered. This TBD should be revised to clarify the potential for external 

exposures to unmonitored workers given primary consideration when determining 

environmental occupational dose. Also, given the new documents that are available for 

K-25, it may be appropriate to update this chapter. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

145 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

(9) The background gamma radiation levels provided in Table 4D-4 of the K-25 

Occupational Environmental Dose TBD (East 2006, pg. 21) are those reported at the two 

perimeter ORGDP stations, HP-33 and HP-35. Has NIOSH/ORAU considered that doses 

to unmonitored workers working outside buildings might receive doses higher than what 

are reported at the site boundary? 

Response - There is a potential that unmonitored workers received an external dose 

higher than those reported at the site boundary. This TBD should be revised to clarify 

the potential for external exposures to unmonitored workers given primary consideration 

when determining environmental occupational dose. Also, given the new documents that 

are available for K-25, it may be appropriate to update this chapter. 

(10) Note that for estimated air concentration data used to calculate intakes, the distance was 

adjusted (reduced) to account for intakes near the release points. Has NIOSH/ORAU 

considered performing a similar exercise to account for ambient radiation doses to 

unmonitored workers outside of buildings within the site boundary? 

Response - As stated in Question 9, there were no modifications of the external dose to 

unmonitored workers; the radiation dose reported by the perimeter monitors was used 

for the potential environmental exposures. This TBD should be revised to clarify the 

potential for external exposures to unmonitored workers given primary consideration 

when determining environmental occupational dose. Also, given the new documents that 

are available for K-25, it may be appropriate to update this chapter. 

(11) Did a Cascade Improvement Program or Cascade Upgrade Program exist at K-25 similar 

to that at PGDP resulting in releases that may have contributed to unmonitored worker 

internal and external dose? 

Response - Information about the changes to the K-25 Cascade were not available at the 

time that Chapter 4 of the TBD was developed. It is possible that the changes to the 

cascade may have contributed to the radiation dose of the unmonitored workers. The 

current TBD addressed what is believed to be the major contributors to exposure, but as 

additional information becomes available and if it indicates modifications are warranted, 

the TBD will be revised. 

(12) What exposure routes are included in the dose reconstruction for environmental dose 

(e.g., stack releases, direct exposure, soil resuspension, etc.)? 

Response - As described in Chapter 4 of the TBD, the pathways for exposure are 

inhalation and external exposure. Source terms were used from the ORDR to estimate the 

environmental airborne concentrations and the basis for potential exposure to 

unmonitored workers. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

146 of 191 

 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

(13) How did NIOSH define the site boundaries verses the site fence line? 

Response - As stated in Section 4.2.1, the monitoring stations were located at the 

boundary of the Oak Ridge Reservation, approximately 2500 meters from the center of 

the K-25 plant. The K-25 site fence line is generally less than 100 meters from the 

process buildings. 

(14) Which environmental results are in K-25 reports and which are in ORNL reports? 

Response - There were no environmental results specific for K-25 available at the time 

that the TBD was developed. The estimate of source terms for K-25 were published in the 

ORDR and modified to estimate the potential exposure to unmonitored workers. The 

current TBD addressed what is believed to be the major contributors to exposure, but as 

additional information becomes available and if it indicates modifications are warranted, 

the TBD will be revised. 

(15) Please explain why NIOSH has concluded that air concentration levels were not 

associated with releases from other than K-25 operations?
 

Response - It is likely that the air concentrations detected at the reservation boundary 

were the combination of K-25 as well as other Oak Ridge operations. There was no 

defensible manner to segregate the releases from K-25 from the other operations at Oak 

Ridge. In a manner that was claimant favorable, it was assumed that all activity detected 

at the monitoring stations was associated with K-25. 

OCCUPATIONAL INTERNAL DOSE (ORAUT-TKBS-0009-5) 

(1) How will NIOSH review the bioassay database for accuracy (verification and 

validation)? 

Response – ORAUT-RPRT-0022, Analysis of Electronic Personnel Exposure Data from 

Y-12, addresses the issue of Y-12 data, which are maintained in the same database as K25 data. While K-25 data are not specifically verified in this report, they are mentioned 

in the document because many people worked at both facilities. The report also states 

that a similar analysis (to that done for Y-12) will be performed for the K-25 data. This 

analysis is pending. 

(2) For bioassay of radionuclides that occur naturally (uranium, thorium, etc.), how will 

NIOSH handle the determination of the occupationally contributed component in the 

bioassay sample in a claimant-favorable manner? Should the average background for the 

population be used or an individual specific background (if available)? Is the average 

value the most appropriate to use or the –1 standard deviation (σ) value for background 

subtraction? 

Response - When assessing intakes based on uranium urinalyses, our standard procedure 

has been to assume that the entire result is due to occupational exposure because of the 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

147 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

large variability in the natural background and its dependence on personal habits (such 

as drinking water source) of the individual. No background subtraction is performed. 

(3) Is NIOSH going to investigate if there is any site-specific airborne radionuclide particle 

size analysis data available (determination of actual activity median aerodynamic 

diameters) that will result in more claimant-favorable assessments? 

Response - Particle size distributions are generally specific to operations and physical 

conditions in the locations where work is performed. It is not reasonable to assume a 

measurement of particle size in one location is universally applicable to other locations. 

Therefore, as instructed in Section 5.4 of the TBD, a particle size assumption of five (5) 

micrometer AMAD is assumed by the dose reconstructors unless there is site-specific 

information to the contrary. 

(4) NIOSH does not identify any use of radionuclide intakes for medical intervention in the 

TBD. This infers that there were no major radionuclide intakes requiring medical 

intervention in the history of the site. Does NIOSH plan to investigate this further? How 

will NIOSH handle dose reconstruction for any workers that had medical intervention 

treatments for minimizing internal dose? 

Response - The primary nuclide of interest at K-25 is uranium. DTPA is not approved for 

use for mitigating uranium intakes. Sodium bicarbonate can be used; if noted in the 

claimant file the dose assessment would take this into account. 

(5) No information on radiological surveying, air sampling data, use and evolution of applied 

air concentration limits / action levels, or use of respiratory protection are discussed 

which would give information on the radionuclide air concentrations and surface 

contamination that workers could have been exposed to. Has NIOSH reviewed any 

monitoring data and respiratory protection program information to determine if it has any 

usefulness in the internal dose reconstruction effort? 

Response – The dose reconstructions use individual monitoring data as the primary 

method of evaluation because it is more representative of a given individual. Because 

uranium has a long half life, just a few measurements are adequate to approximate the 

exposure, provided there are results through the end of employment. There is a coworker 

study that spans most of the history of the site (recent years have not yet been modeled); 

if it is determined that additional information is necessary, area monitoring information 

will be reviewed. 

(6) NIOSH states that there are no incident reports where there was a potential for internal 

doses available. Does NIOSH plan to do a thorough search of the incident information 

available in order to identify as many incidents with internal dose significance as possible 

to assist the dose reconstructors? Incident reports often provide very useful information 

for accurate dose reconstruction. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

148 of 191 

 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Response - Section 5.7 of the TBD acknowledges that no incident information is currently 

available. The CATI provides another opportunity for claimants to give information on 

incidents. As incidents are identified, they may be captured in future revisions of the 

TBD. 

(7) Has NIOSH reviewed any contamination monitoring (air and/or surface) that may have 

been done in areas around the perimeter of airborne and surface contamination areas to 

determine if workers in these areas may have had intakes at some frequency without 

being participants in bioassay? 

Response - This issue is addressed in K-25-4, “Occupational Environmental Dose.” 

(8) Has NIOSH identified any 226Ra or 228Ra sources of significance handled in the site 

history that would require assessment of doses from radon or thorium? 

Response - No information on the presence of radium sources at the site is currently 

available. 

(9) The Site Description TBD identifies 1977 as the last year of uranium recycling from 

reprocessing spent fuel, but this TBD identifies 1976. How will NIOSH decide which 

year is correct? This can be critical for assessing intakes that occurred in 1977 in order to 

provide claimant-favorable assessments. 

Response - Table 3.4-1 of the “Recycled Uranium Mass Balance Project”, referenced as 

(BJC 2000) in the TBD, states that recycled uranium was received at K-25 from 1952 

through 1988. For clarity, however, the first paragraph of Section 5.3 of the TBD will be 

revised to include the entire time period when recycled uranium was received, rather 

than just the start date. 

(10) Tables 5-4 and 5-5, which list source terms and facility-specific radionuclide conversion 

factors (respectively), do not cover all facilities in Table 2-2 of the Site Description TBD. 

Will NIOSH add more facilities to Tables 5-4 and 5-5 to assist the dose reconstruction 

accuracy? 

Response - At this time, the only source term information available is that shown in 

Tables 5-4 and 5-5. If additional source term information should become available, the 

TBD will be revised accordingly. 

(11) Table 5-4 (Source term summary by location) does not show any 241Am, 242Cm, or 244Cm 

at any facilities and these are shown in Table 5-2 as principal radionuclides. Does 

NIOSH have a reason for this apparent inconsistency? 

Response - At this time, the only facility-specific source term information available is 

that shown in Tables 5-4 and 5-5. If additional source term information should become 

available, the TBD will be revised accordingly. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

149 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

(12) Is the default isotope distribution in Table 5-6 claimant favorable? The 99Tc looks low 

when compared to the ratios of uranium activity to 99Tc activity discussed in the Site 

Description TBD. Higher enrichments and the addition of other radionuclides (238Pu,

242Cm, 244Cm) that were identified as principal radionuclides at the site (Table 5-2) would 

increase doses. Note also that 242Pu was identified in the Paducah Internal Dose TBD as 

a radionuclide of concern which came from spent fuel reprocessing and could be assumed 

to be present at K-25 from the same type of source. 

Response - At this time, the only facility-specific source term information available is 

that shown in Tables 5-4 and 5-5. The default distribution in Table 5-6 was drawn from 

the same references. If additional source term information should become available, the 

TBD will be revised accordingly, as will the default isotopic distribution. 

(13) Has NIOSH determined whether the urine bioassay results may need adjustment before 

input into IMBA to account for the variability of spot samples compared to 24-hour 

samples, and how will NIOSH adjust these if needed? 

Response - As described in Section 5.5 of the TBD, urine samples were collected as both 

“spot” samples and as 24-hour collections, with the latter the standard procedure after 

1950. If the measurement results are given in units of concentration, the dose 

reconstructors will convert them to 24-hour-equivalent excretion rates by using the 

Reference Man volume in ICRP Publication 23. If results are given in units of activity 

only, a 24-hour collection may be presumed if the date of the analysis is after 1950. 

(14) Has NIOSH looked at any other uranium bio-kinetic models for UF6 to determine if these 

could be more claimant favorable (Fisher et al. 1991)? 

Response - No, this has not been reviewed. 

(15) Has NIOSH determined the frequencies of sampling throughout the history of the 

bioassay program and how to determine potential intake dates for long periods between 

samples? 

Response - The frequency of sampling as a programmatic issue is not a useful piece of 

information; the worker sample results are in the DOE files so the required frequency is 

irrelevant after the fact. 

Because uranium is long-lived and long-retained, a dose reconstruction can be 

performed with very few results. Chronic intakes are assumed for the majority of workers 

(at all sites) and a gap of many years does not affect the assessment. 

(16) Does NIOSH have a process of determining which enrichments a worker could have been 

exposed to for their intake assessments? This is critical because the doses can vary 

substantially depending on the enrichment assumed when interpreting mass concentration 

(μg/liter) bioassay data. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

150 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Response - As described in Section 5.3 (footnote 2) of the TBD, the predominant 

enrichment level at K-25 was 3%, except for the period of time when reprocessed fuel 

was used as feed. The dose reconstructors will select the input parameters on enrichment 

based upon the dates of exposure for each claimant. 

(17) What is the basis for assuming 2% enrichment as a default for isotopic fractions? When 

is the default isotopic fraction used in dose reconstruction? How does NIOSH determine 

whether an alternate isotopic fraction should be used? 

Response - Because the predominant enrichment level at K-25 is described in Section 5.3 

as being 3%, Table 5-1 will be revised to capture this level as the default. 

(18) Please provide more detail and the basis why the Y-12 monitoring history was assumed 

for K-25 rather than using K-25’s monitoring history as it’s not explained well in the 

TBD. 

Response - The availability of records and documentation for K-25 was limited as of the 

current revision date of the TBD. Therefore, and as stated in Section 5.5, the 

programmatic elements of the Y-12 monitoring program was assumed because there was 

evidence of professional interactions between the two organizations and the two plants 

were in close proximity. If K-25-specific records showing deviations from the approach 

described in the TBD should become available, the TBD will be revised accordingly. 

(19) Table 5-3 lists seven chemical forms of uranium, yet the TBD does not provide a 

correction factor for situations where samples were collected after two days. This is 

particularly important in detecting acute intakes. Why has a correction factor not been 

considered? 

Response - Table 5-3 contains the absorption factors for the various chemical forms of 

uranium present at the site. If a claimant has knowledge of the chemical form of the 

materials with which he/she worked, the dose reconstructor will use that information, 

along with the relevant assumptions on monitoring frequency and intake pattern, to 

reconstruct the dose. If information on chemical form, monitoring frequency and intake 

pattern are unknown, the default assumptions described elsewhere in the TBD would be 

applied in a manner which is favorable to claimants. 

(20) Has NIOSH investigated the calibration procedures for the Y-12 mobile in vivo counter, 

apparently used at K-25 and whether these calibrations were accurate? 

Response - No data, information or documentation exists at this time that would offer a 

means of “correcting” the in-vivo results obtained using the Y-12 mobile counter even if 

evidence exists that its calibration factors were questionable. If such data, information or 

documentation should become available, the TBD will be revised accordingly. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

151 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

INTERNAL DOSIMETRY COWORKER DATA FOR K-25 

(1) Is NIOSH considering the use of any air sampling or surface contamination data to 

reconstruct doses for the pre-1948 period?
 

Response - The OTIB has been extended back to the start of the site. 

(2) Has NIOSH tried to determine if the radiological controls in the pre-1948 period were 

significantly less stringent and exposures could have been higher than after this period? 

Were processes and production levels the same? This may require consideration of a 

multiplier to adjust the extrapolated data for significant differences if these exist. 

Response - This information was not available, so other approaches were used to 

extrapolate to that time period (see Attachment C of the coworker OTIB for complete 

details). Most significantly, a review of the urine data from 1948-1988 for 120 of the 

workers who were working at K-25 from 1945-1947 confirms the fact that they were 

indeed typical workers from 1948-1988, which supports the belief that they would have 

been typical workers during 1945-1947. Had they had larger intakes in the early years, 

their bioassay results would have reflected this in the years when bioassay samples were 

collected. 

(3) Is the assumption of modeling chronic intakes appropriate? Note that the Internal Dose 

TBD states, “The expected intake pattern in most cases is acute.” Will acute intakes give 

more claimant-favorable assessments? 

Response - Because it is not possible to model all possible intake scenarios, the default 

assumption of chronic intakes has been applied across the complex when there is not 

specific information for a given individual. This assumption can be used to approximate a 

series of small acute intakes, which is likely more representative of the actual pattern. 

(4) Why are assigned doses calculated from the 50th-percentile intake rates rather than the 

84th-percentile (+1 standard deviation) intake rates? Is there a rationale to justify not 

using the higher possible intake rates? 

Response - It is assumed that an individual who was never monitored did not have the 

potential to have received larger intakes than the majority of those who were monitored. 

It is assumed that the coworker distribution is representative of their intakes; the median 

dose is therefore assigned as a lognormal distribution and the associated GSD is 

assigned to account for possible larger intakes and the uncertainty associated with the 

distribution. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

152 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

(5) Has NIOSH determined the appropriate enrichments to assume during this period, which 

will control the total U activity for intakes? 

Reference: 

Fisher, D. R., Kathren R. L, and Swint, M. J., 1991, Modified Biokinetic Model for 

Uranium from Analysis of Acute Exposure to UF6 , Health Physics. 60(3):335-342, 

March 1991 

Response - Not certain what is meant by “this period.” However, only gross alpha (units 

of activity) results were used for the history of the site in the coworker evaluation so the 

enrichment does not affect the outcome. The total uranium activity is assessed as U-234. 

OCCUPATIONAL EXTERNAL DOSE (ORAUT-TKBS-0009-6) 

(1) Different documents refer to the NTA dosimeter neutron having a cutoff at energies 

varying from 0.5 MeV to 1.0 MeV. This may be significant for neutron fields anticipated 

at K-25. The Occupational External Dose TBD (Miles 2006 – pg. 8) points out that “The 

dosimeter response for photon energies greater than 0.06 MeV is of primary interest for 

K-25 workers.” How is the threshold considered and applied at K-25? Is there data to 

support the value being applied at K-25 over the extended timeframe and workplace 

conditions that NTA was in use? 

Response - Personnel external dosimetry at K-25 was provided using what is termed the 

ORNL personnel dosimeters as described in the Site Profile. The photon energy response 

of this dosimeter type is illustrated in Figure 6-1 showing that it is capable of reasonable 

response to K-25 photon fields. Confirming documentation of the response of this 

dosimeter design to selected photon beams is presented in publications by AEC (1955), 

Parish (1982), Wilson et al. (1990) and Thierry-chef et al. (2002). The missed neutron 

dose, as applied by the dose reconstructor based on considerations from the claim, CATI 

and Site Profile, is estimated by applying a neutron to photon dose ratio of 0.2 to the 

measured and missed photon dose. There is no consideration in this approach of the NTA 

neutron energy threshold. 

References; 

AEC (U.S. Atomic Energy Commission), 1955, “Intercomparison of 

Film Badge Interpretations,” Isotopics, Volume 2, number 5, pp. 8–23. 

Parish, B. R., 1982, Evaluation of External Personnel Monitoring 

Devices and Data for Oak Ridge National Laboratory Epidemiological 

Study, University of North Carolina, Chapel Hill, North Carolina. 

Thierry-Chef, I., F. Pernicka, M. Marshall, E. Cardis, and P. Andreo, 

2002, “Study of a Selection of 10 Historical Types of Dosimeter: 

Variation of the Response to Hp(10) with Photon Energy and Geometry 

of Exposure,” Radiat Prot Dos, 102(2): 101-113. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

153 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Wilson, R. H., J. J. Fix, W. V. Baumgartner, and L. L. Nichols, 1990, 

Description and Evaluation of the Hanford Personnel Dosimeter 

Program From 1944 Through 1989, PNL-7447, Pacific Northwest 

Laboratory, Richland, Washington. 

(2) Have any “slow cooker” events been documented or postulated at the K-25 site? If so, 

what doses have been assigned to individuals and various cohorts? (See HETA 96-0198­

2651 report on Portsmouth Gaseous Diffusion Plant for description of potential 

problems.) If not, what evidence is there to support the lack of this kind of event at 

K-25? 

Response - Slow cooker effects were considered during worker outreach comment 

review. Neutron exposures were monitored and there is guidance in the TBD section 

6.7.3 for estimating missed and unmonitored neutron dose using the neutron-to-photon 

ratio of 20% for dose equivalent. 

(3) What type of incidents have occurred over the years that may have impacted external 

doses, and how would those dose estimates, if any, be assigned to individual records? 

Response - Incidents were reviewed during the research for the TBD. DOE 2000b, 

Independent Investigation of the East Tennessee Technology Park [SRDB Ref ID: 13787] 

notes that there were numerous spills and releases but that these were not always well 

documented. The CATI would reveal information about specific individual’s exposure. In 

addition, Incident Investigation Reports are requested during the NIOSH Request for 

Exposure Information. 

(4) Was industrial radiography performed on site during construction, maintenance, 

modification or QA inspections? If so, what procedures were in place to prevent 

inadvertent entry to radiation areas? 

Response - Industrial radiography was likely performed at K-25. Information was not 

found during site research about specific procedures used to control areas during 

radiography. It is presumed that the then current industry standards were applied to 

control of areas during radiography. 

(5) In Section 6.5.2.1 of the Occupational External Dose TBD (Miles 2006), under response 

of dosimeters to photons of <60keV, they are considered to be of no consequence. Is this 

assumption valid, given that some operators are exposed to extended, unshielded sources 

of material during contamination incidents, maintenance or other routine activities such 

as cylinder washing? 

Response - The ORNL type film dosimeter used at K-25 had an open window with 

minimal filtration that would significantly respond to lower energy photon radiation as 

illustrated in Figure 6-1 whereas the filtered region of the film would have had a 

decreasing response as the photon energy decreased. The combination of the open 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

154 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

window and filtered response of the film would assure that no significant photon dose 

would be missed. 

(6) What efforts have been made to identify whether experimental or non routine R&D type 

activities were performed throughout the site evolution? 

Response - Special dosimetry considerations for experimental or non routine activities 

would have been addressed by the health physics job planning and practices in place at 

the time. It was noted that as early as 1949 finger rings were used [Levine 1949]. 

Levine 1949, Dr. H.V., Ring Film Processing [SRDB Ref ID: 864] 

(7) Section 6.5.2.2 of the Occupational External Dose TBD states that neutron doses ranged 

up to “less than 0.05mSv/hr...” It also states in the same paragraph that there was 

minimal potential for significant neutron doses. Given that 2000 hours/year at the upper 

bound of the “minimal” dose rate would result in an annual neutron dose of 100mSv, or 

10 rem, how is this statement supported? 

Response - None of the documents reviewed indicated that individuals were exposed 

continuously to neutron fields of 0.05mSv/hr. The upper range of the neutron dose rates 

cited in ORAUT-TKBS-0009-6 was not meant to define minimal dose. Neutron 

monitoring results reviewed in the NOCTS claim files do not support high neutron 

exposures; the individuals with the highest potential for neutron exposure were 

monitored. 

(8) Section 6.5.3.1 of the Occupational External Dose TBD states that all beta dose 

determinations were for a uranium slab calibration. Where are the supporting references 

to show that any errors associated with this assumption are reasonable and claimant 

favorable? 

Response - Calibration factors established from a depleted uranium slab are assumed to 

closely match the radionuclide beta energies at the K-25 gaseous diffusion plant and 

represent the appropriate selection for determining the shallow dose equivalent 

Hp(0.07). As noted in Figure 6-1, the open window response to lower energy photons will 

substantially over-estimate the shallow dose based on a uranium shallow dose 

calibration. 

(9) Section 6.5.4 of the Occupational External Dose TBD discusses 99Tc betas (maximum 

energy 294 keV). The claim is made that film dosimeters and TLDs will not detect 99Tc 

betas efficiently and that only skin contamination could cause significant shallow dose. 

As it is a given that the dosimetry would not detect the betas, what evidence is there that 

workers were never exposed to large extended sources of 99Tc? What are the typical and 

largest Curie amounts of 99Tc that the workers encountered during normal operations and 

what would the resultant radiation dose rates have been? (Beta and bremsstrahlung 

fields) 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

155 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Response - The primary means to detect and measure 99Tc was through radioanalyses of 

samples because of the low-energy beta emission. The highest concentrations of Tc-99 

were found in the ORGDP Stream 21 - Cascade Accumulation Stream. Information to 

answer the specific question about defining the “typical and largest Curie amounts of Tc99 that workers encountered during normal operations...” was not found in the site 

research. 

Bechtel Jacobs 2000, Recycled Uranium Mass Balance Project Oak Ridge Gaseous 

Diffusion Plant, provides “estimated levels” of Tc-99 at various locations in the plant. 

Tables 5-4 and 5-5 of the internal dose technical basis document (ORAUT-TKBS-0009-5) 

provide the relative concentrations of the radionuclides at various locations. Tc-99 will 

not produce significant bremsstrahlung radiation due to the relatively low energy beta 

radiation emission. 

(10) Section 6.5.4 of the Occupational External Dose TBD states “...99Tc was concentrated at 

K-25 for the purposes of recovery and removal.” What processes were involved and 

what Curie levels and concentrations were typically and potentially encountered? What 

potential dose rates due to wide area beta sources (peak energy 294 keV) were present? 

Response - 99Tc is considered a potential significant nuclide associated with recycled 

uranium to provide a major source of bremsstrahlung radiation from the beta radiation 

emission, if present in significant quantity. Based on the NIOSH review of Portsmouth 

(Cardarelli, 1996), very low rates of gamma and bremsstrahlung radiation were found 

with the highest levels found in feed cylinder handling areas. The precise activity levels 

are not known, at least in the context of the K-25 TBD. 

(11) Section 6.5.4 of the Occupational External Dose TBD (Neutron Fields). Where is the 

supporting evidence for claiming that the neutron-to-photon measured ratio at Paducah 

during a single project is applicable to the entire history of K-25? Likewise what is the 

basis for the Y-12 small cylinder measurements as stated in Section 6.5.3.2? 

Response - The Paducah neutron:photon ratio and the Y-12 measurements were 

provided as related technical information that was available to determine a realistic 

neutron to photon dose ratio because of the similarity in handling enriched uranium 

among these plants. As described in 6.5.3.2, measurements with a tissue equivalent 

proportional counter (TEPC) at Y-12 were supported by similar (although qualitative) 

measurements made in 1993 with a TEPC at the K-25 cylinder yard. Discussions with 

ORNL staff involved in these measurements confirmed that the neutron dose rates were 

very low, necessitating long measurement periods with associated greater uncertainty. 

(12) Section 6.5.2.2 of the Occupational External Dose TBD states that neutron capable TLDs 

were provided from around 1988, but read on an “as needed” basis. What criteria were 

used to determine when the dosimeters were read and what evidence is there that this 

policy and procedure were adequate and claimant favorable? 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

156 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Response - The TLDs were processed using a fully automated reader system. The TBD 

should likely have stated that the neutron dose was not fully evaluated because of the 

difficulties associated with the low dose rate, the neutron spectra and the selection of an 

appropriate neutron dose calibration. The criteria to assess the neutron dose may have 

been different during different time periods. The TLD neutron dose was available for 

evaluation in the event of an incident. 

(13) Section 6.5.2.2 of the Occupational External Dose TBD also states that “higher neutron 

sensitivity” TLDs were used in some cases. Given that neutron fields were stated to be 

“minimal” why was this done? What types of dosimeters were used and what is the 

impact of this information on decisions affecting dose determinations? 

Response - The types of neutron badges are presented in Table 6-1. The neutron dose 

rates are typically so low that accurate measurement of the actual neutron dose has been 

a challenge. The Harshaw TLDs are available in different models with some models 

having a higher neutron sensitivity. 

(14) Section 6.5.3.1 of the Occupational External Dose TBD states that the move to phantom 

based photon calibration would have resulted in overestimated doses. Please explain the 

thinking here as to why this is not taken into account in the full calibration system. 

Response - Section 6.5.3.1 should be revised to say, “Photon calibrations without the use 

of a phantom tended to cause overestimated doses...” 

In the 1980s, studies at a number of laboratories assessed changes from the on-phantom 

calibration mandated by the DOELAP testing criteria (Fix et al. 1982; Wilson 1987; 

Wilson et al. 1990; Taylor et al. 1995). 

Fix, J. J., J. M. Hobbs, P. L. Roberson, D. C. Haggard, K. L. Holbrook, M. R. Thorson, 

and F. M. Cummings, 1982, Hanford Personnel Dosimeter Supporting Studies FY-1981, 

PNL-3736, Pacific Northwest Laboratory, Richland, Washington. 

Wilson, R. H., 1987, Historical Review of Personnel Dosimetry Development and its Use 

in Radiation Protection Programs at Hanford, 1944 to the 1980s, PNL-6125, Battelle 

Memorial Institute, Pacific Northwest Laboratory, Richland, Washington, February. 

[SRDB Ref ID: 262] 

Wilson, R. H., J. J. Fix, W. V. Baumgartner, and L. L. Nichols, 1990, Description 

and Evaluation of the Hanford Personnel Dosimeter Program From 1944 

Through 1989, PNL-7447, Pacific Northwest Laboratory, Richland, Washington. 

Taylor, G. A., K. W. Crase, T. R. LaBone, and W. H. Wilkie, 1995, A History of 

Personnel Radiation Dosimetry at the Savannah River Site, WSRC-RP-95-234, 

Westinghouse Savannah River Company, Aiken, South Carolina. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

157 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

(15) Section 6.7.1 of the Occupational External Dose TBD refers to use of the (MDL)/2 

approach to estimate missed doses. How does this comply with the decision to use the 

claimant favorable 95th percentile approach? 

Response - Using 1⁄2 the MDL for “missed dose” is described in OCAS-IG-001, External 

Dose Reconstruction Implementation Guideline. This guideline goes on to describe the 

method to calculate the 95 % dose estimate for missed dose; generally by multiplying the 

(MDL) times the number of zero measurements. 

Please note that the Technical Basis Document does not provide instruction about 

performing the dose reconstruction, but as described in the purpose, the TBDs are 

“general working documents that provide historical background information and 

guidance to assist in the preparation of dose reconstructions for particular sites..... The 

documents will be revised in the event additional relevant information is obtained about 

the affected site(s).” 

(16) Section 6.7.1 of the Occupational External Dose TBD discusses averaging the doses for 

monitored workers. The claim is made that those that were badged were the most likely 

to be exposed. Please provide procedural, anecdotal and other supporting information to 

support this claim. For instance, how do we know that management did not choose to 

sample a representative cross section of workers and jobs with a range of exposure 

conditions? 

Response - DOE 2000b, Independent Investigation of the East Tennessee Technology 

Park [SRDB Ref ID: 13787] notes that “exposures were primarily monitored by the use 

of film badges assigned to personnel based on their anticipated tasks and work areas.” 

This same document goes on to say “A 1977 study of the lifetime health and mortality 

experience of employees of ERDA contractors noted that the ORGDP procedures from 

1945 to 1974 called for routine monitoring only for employees who worked or entered 

areas with a potential for exposures...” 

(17) Section 6.7.3 of the Occupational External Dose TBD suggests that Paducah data be used 

to define missing neutron dose N: P ratios. What basis is there for relying on this data, 

especially for the early years? Is this approach assumed to be claimant favorable? 

Response - The Paducah neutron:photon ratio was provided for dose reconstructors to 

estimate the K-25 neutron dose due to the similarity in the plants. If better information 

(neutron:photon dose equivalent ratio) specific to the K-25 plant is obtained ORAUTTKBS-000906 should be updated. 

(18) What is the basis for applying a single neutron-to-photon ratio from a specific work task 

at a sister facility? The enrichments of uranium differed between K-25 and Paducah with 

K-25 handling higher enrichments. The alpha, n reaction for higher enrichments by 

weight would increase as the enrichment increases. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

158 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Response - Dose reconstruction practices at K-25, Portsmouth and Paducah Gaseous 

Diffusion Plants are similar in that a neutron-to-photon dose ratio is applied to measured 

and missed photon dose for some workers depending upon work activities. The studies of 

neutron doses by Cardarelli (NIOSH Health Hazard Evaluation Report 96-0198-2651), 

PNL (1990) and ORNL (1993) as noted in the K-25 TBD all indicate very low dose rates 

to the extent that accurate measurement of the neutron dose component is uncertain. 

ORNL has provided TLD dosimetry at various times to Paducah and Portsmouth in 

addition to their monitoring at Y-12, K-25 and X-10. The TLD measured neutron doses 

are comparatively low. The neutron dose component is certainly associated with the 

enrichment, the chemical form and configuration, and primarily associated with uranium 

storage and locations in the process where uranium residues can concentrate (i.e., slow 

cooker phenomena). 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

159 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

 

Attachment A 

Responses to Worker Outreach Comments at K-25
 

Comment: How often is the urinalysis test required? 

Response: Frequency was added to Section 5.4 of ORAUT-TKBS-0009 Rev. 0 PC-1A 

Comment: The thermoluminescent dosimeters (TLDs) for guards at K-25 always read zero. 

Because guards have worked and continue to work in every building on the site, the guards do 

not believe the paperwork that they receive regarding their exposures. 

Response: Guidance for external dose reconstruction is provided in OCAS-IG-001 and 

ORAUT-OTIB-0020, Use of Coworker Dosimetry Data for External Dose Assignment and 

ORAUT-OTIB-0026, External Coworker Dosimetry Data for the K-25 Site 

Comment: At East Tennessee Technology Park (ETTP), we have quite a few new concerns 

about possible worker exposures. People wonder why you need a TLD or Personnel Nuclear 

Accident Dosimeter (PNAD) when you go past Portal 11 into limited areas. We do have areas 

that contain numerous UF6 (uranium hexafluoride) cylinders. Many of the UF6 cylinders that 

they are receiving in Paducah are coming from our site. 

Response: The use of TLDs and/or PNADs is governed by site procedures for access to 

radiologically-controlled areas. UF6 cylinders are discussed in Section 6.5.4, Workplace 

Radiation Fields, in ORAUT-TKBS-0009 Rev 0 PC-1. The receipt at Paducah of K-25 cylinders 

is discussed in the Paducah Site Profile. 

Comment: In times past, a dried up vial of a cousin to the West Nile Virus was found in K-25. 

When they were doing the clean up on K-31 and K-33, they found things that were not supposed 

to be in those buildings. I have also heard stories from guards who said that years ago they 

would have releases at night so that the releases would not be seen. 

Response: Discussion of non-radiological hazards is not appropriate for this Site Profile. 

Atmospheric releases of uranium and other radioactive materials are addressed in ORAUTTKBS-0009-4. 

Comment: Using data from Portsmouth and Paducah to write the K-25 Site Profile is not 

appropriate. There are huge differences in the percentages of enrichment. It is also important to 

remember that K-25 was more experimental than Paducah and Portsmouth. 

Response: As gaseous diffusion plants, these sites share similarities in processes. The Site 

Profile contains K-25 specific material. 

Comment: I remember traps and converters starting on fire. Men died in their 40s and 50s due 

to exposures working at K-25. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

160 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Response: No discussion of fires in traps or converters was found in K-25 documents. Fires are 

discussed in the reference ORAUT-TKBS-0009-4 - "DOE (U.S. Department of Energy), 2000b, 

Independent Investigation of the East Tennessee Technology Park." 

Comment: The Uranium Mass Balance Report only considered production/process buildings. 

Response: The Mass Balance Report is only one of many references used. 

Comment: The J Lab Facility had a Plutonium Program which processed plutonium. 

Response: The processing of transuranic elements is discussed in ORAUT-TKBS-0009-5. 

Comment: We know that there were specific operations occurring throughout the gaseous 

diffusion plants (K-25, Paducah, and Portsmouth) that would be useful to the dose 

reconstructors. Some areas had different ratios. If you get this type of information and it is 

verified, will the site profiles change to reflect the new information? 

Response: Yes, the site profiles are revised as new information becomes available. The ratios 

you mentioned are discussed throughout the site profiles for the gaseous diffusion plants. 

Comment: Transuranics plate out in various stages of the cascade. The Operational Report 

from Portsmouth only checked for UF6, not for solids. There would be different transuranics 

depending on where you are cutting into the system. Different ratios affect exposures. 

Response: ORAUT-TKBS-0009-5 discusses transuranics at many stages of the enrichment 

process not just Paducah UF6. 

Comment: Workers are very concerned that NIOSH is only looking at data that are being 

provided directly to them. We have heard countless stories about workers who were removed 

from a job because their badge readings were so high. However, when these same workers got 

their badge reading reports back, they had zeros. In addition to the false zeros, many workers 

cannot locate their medical records. This all seems like a cover-up. 

Response: The intent of the Site Profile is to provide a facility description based on the best 

availble information. Reconstruction of dose is covered by OCAS-IG-001 and OCAS-IG-002. 

Comment: Documented calibration procedures, instrument types, and monitoring frequencies 

for the K-25 site would help out with the dose reconstruction calculations. 

Response: These are included throughout the K-25 Site Profile. 

Comment: Have you seen any procedures regarding the TLDs for K-25? 

Response: Yes. Bechtel Jacobs Procedure EH-4511, "External Dosimetry" was reviewed in 

preparation of the Site Profile. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

161 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Comment: Page 5, Section 2.2—References “characterization studies to date,” what are these 

characterization studies? 

Response: The text was changed to list the source of the studies (Bechtel Jacobs Mass Balance 

Report.) 

Comment: Page 7, Section 2.2.2—References “characterization studies.” I think that you are 

referencing one survey and basing all of your information on that one survey. Please find out if 

this is the case. 

Response: The text was changed to list the source of the studies (Bechtel Jacobs Mass Balance 

Report.) 

Comment: The External Dose section of the K-25 Site Profile does not mention slow cooker 

effects. 

Response: Slow cooker references were reviewed and it was determined that their mention did 

not add any beneficial information for the dose reconstructors. 

Comment: There was a Deposit Removal Project that took place at K-25 in which highly 

enriched uranium deposits were removed. I am not sure if this is noted in the K-25 Site Profile 

or not. 

Response: Uranium recovery is discussed in ORAUT-TKBS-0009-2. 

Comment: NCS documents as well as other references could provide another source of 

validation for K-25 data. 

Response: All available documents including Nuclear Criticality Safety (NCS) are reviewed to 

develop the Site Profiles. 

Comment: Building 1401 had a compressor shop and a converter maintenance shop. The 

southwest corner had ovens that recovered highly enriched uranium from converters. I believe 

that Building 1401 had to contain transuranics. I checked vent stack information and found out 

that 58 pounds of uranium-containing material were removed from one vent stack in a single 24- 

hour period. 

Response: The presence of recycled uranium and transuranics is diiscussed throughout the site 

profile. In particular, the presence of TRU in Building 1401 is mentioned in ORAUT-TKBS0009-2. 

Comment: After dark, the incinerator in Building 1421 was used to burn anything and 

everything (rags, clean up materials from spills). 

Response: Atmospheric releases of Uranium and other radioactive materials are addressed in 

ORAUT-TKBS-0009-4. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

162 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Comment: Building 1405 was a High Temperature Laboratory andI have been told that lots of 

highly enriched uranium was used in that building. 

Response: Highly enriched uranium at K-25 is discussed in ORAUT-TKBS-0009-6. 

Comment: The 131 Pipe Shop Maintenance building rebuilt parts. Parts were robbed from the 

K-25 building itself and used throughout the plant and then machined in Building 1401. 

Response: Documentation was not found in the Site Research Data Base. Due to the Site 

Profile's consideration of wide spread contamination and elevated dose rates throughout the 

facility it is unlikely that this would have significant impact on dose reconstruction. 

Comment: Building 631 was the “Test Loop” Tails Withdraw Facility. 

Response: Documentation was not found in the Site Research Data Base. Due to the Site 

Profile's consideration of widespread contamination and elevated dose rates throughout the 

facility, it is unlikely that this would have significant impact on dose reconstruction. 

Comment: The sanitary water system was crossed with the fire water system resulting in the 

sanitary water containing strontium and cesium. 

Response: Documentation was not found in the Site Research Data Base. 

Comment: The K-25 Site Profile does not discuss vaults. We had hot vaults at K-25. 

Response: Documentation was not found in the Site Research Data Base. Due to the Site 

Profile's consideration of widespread contamination and elevated dose rates throughout the 

facility, it is unlikely that this would have significant impact on dose reconstruction. 

Comment: Section 6.5.3—Are there any other data sources available regarding neutron 

exposure before 1989? Has there been any attempt to correlate information? 

Response: Section 6.7.3 of ORAUT-TKBS-0009-6 discusses assesment of missed or 

unmonitored neutron dose. 

Comment: The Blair Gate/Gallaher Gate Monitoring Stations kicked on once a week for 24 

hours. This could have been done on Sunday when there would have been less to monitor. 

Response: Because of the known limitations of air monitoring, ORAUT-TKBS-0009-4 

calculates environmental intakes based on releases of materials. 

Comment: A word of caution regarding using environmental data for validating – the 

environmental badges did not pick up neutron exposures because there was no phantom in place, 

so no whole body dose could be measured. Neutron monitoring was not being done as properly 

as it should have been. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

163 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Response: As documented in ORAUT-TKBS-0009-4, neutron exposures were not reported for 

environmental results until 2003. 

Comment: Workers question whether instruments were calibrated correctly, so please check 

into the procedures used, especially for cesium-137. 

Response: Review of records availble in the SRDB gived no indication of what source(s) were 

used for photon calibration; only that they be "NBS" traceable. 

Comment: Section 6.5, Page 13—approaches for estimating missed dose. What source 

document did you use for Tables 6.4 and 6.5? Has this been validated against source records? 

Response: Tables 6-4 and 6-5 were deleted from ORAUT-TKBS-0009-6 and replaced with 

Table 2 from ORAUT-OTIB-0026 which was developed from data from the Comprehensive 

Epidimiologic Data Resource (CEDR). 

Comment: There were a lot of system breaks with the Toxic Substances Control Act (TSCA) 

Incinerator. For example, one employee was told that the system was depressurized when it was 

not. Another employee was never told that he was in contact with transuranics until after his 

exposure. 

Response: Specific incidents are covered in the computer-assisted telephone interview (CATI). 

No specific references to incidents at the TSCA incinerator were found in the SRDB. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

164 of 191 

 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

ATTACHMENT 4: SUMMARY OF CONFERENCE CALLS ON SC&A 

QUESTIONS PROVIDED TO NIOSH 

INTRODUCTION 

SC&A submitted written questions to NIOSH pertaining to the K-25 Site Profile on November 9, 

2006. NIOSH/ORAU provided written responses to these questions on December 13, 2006, in 

preparation for a conference call with SC&A. The questions and responses are provided in 

Attachment 3. Information provided by NIOSH/ORAU gives SC&A a more in-depth knowledge 

of the rationale for assumptions made within the TBD and the source documents that provide the 

basis for the TBD. The summaries below are not verbatim discussions, but include information 

supplemental to the written responses provided by NIOSH/ORAU. They are arranged by general 

topics, since there was overlap in discussions conducted during the conference calls. The 

information provided by NIOSH/ORAU is listed under each topic. SC&A has provided 

comments toward the end of the summary. Action items resulting from discussions in the 

conference call are listed at the bottom of each summary. The Issue Resolution Conference Call 

for the K-25 Occupational External Dose TBD was held on January 18, 2007, and the Issue 

Resolution Conference Call for the K-25 Occupational Medical Dose TBD, the Occupational 

Environmental Dose TBD, and the Occupational Internal Dose TBD was held on January 24, 

2007. 

Conference Call Notes on K-25 Issue Resolution for the Occupational External Dose TBD 

Date: January 18, 2007 – K-25 Occupational External Dose TBD 

Participants: 

NIOSH: Chuck Nelson 

ORAU Team: Jack Fix, Paul Szalinski, Betsy Langille, Rob Winslow, Susan Winslow, 

Elyse Thomas 

SC&A: Harry Pettengill, Joe Zlotnicki, Tom Bell 

Introductory Comments: 

SC&A: We are recording the call. The reason we are doing that, if everyone concurs, is so that 

we can get what is said documented accurately. In a couple of hours after the call, there will be 

notation come back to everybody. If it doesn’t get back to everybody on the West Coast, I will 

make sure it gets to you, so that you will be able to go into it and listen to any part of the 

conversation you want to, if you just want to clarify something. That’s the only reason for it. In 

about 8-10 days, the information will just disappear. Is there any particular problem with tape 

recording what we are discussing? Hearing none, let’s go ahead. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

165 of 191 

 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

What we are doing today is going over the responses to our questions. We really do appreciate 

that Jack Fix has made himself available today, since we realize his schedule is full in 

preparation for his upcoming travel in the next 2 weeks. 

What we are doing today is going through these questions as part of our K-25 review. We sent 

out a number of questions to NIOSH on a number of things in the TBD and your responses. 

Over the holiday, we are trying to get around to having the opportunity of having a quick 

conference call to go over the questions and answers with you to see if there is any additional 

clarification between the questions and the NIOSH answers, and if there are any follow-on items 

that either we or NIOSH have to take care of. 

What we have agreed to today, in light of Jack’s travel situation, is that I have Joe Zlotnicki on 

the line, who is the person who did the review of the External Dose TBD. Unless there are any 

other announcements, we will turn it over to Joe, so that we can go though the questions that he 

had submitted and the responses that you, Jack, and others sent back to see if there is anything 

additional there that we have to sort out. 

SC&A: Harry, can I just go over who is on the line. From NIOSH, there is Chuck Nelson, and 

from the ORAU team, Jack Fix, Rob Winslow, Susan Winslow, Paul Szalinski, Elyse Thomas, 

and Betsy Langille. On the SC&A side, there is Harry Pettengill, Joe Zlotnicki and Tom Bell. 

SC&A: (Tom Bell is asking, because he will be responsible for making sure that we get all the 

information down, so that an electronic copy can be provided for review and editing.) 

SC&A: Joe, do you want to go ahead and kick things off? 

OCCUPATIONAL EXTERAL DOSE (ORAUT-TKBS-0016-6) 

General: 

SC&A: We are going to run through the questions and answers, and will indicate whether the 

response was satisfactory, and if I have no further questions, we are not going to spend any 

additional time on them. I think we are going to have a hard time getting through some of them, 

and this will allow more time to focus on them. 

Q.1 SC&A: OK, we are not using the NTA, so the response is fine. 

Q.2 SC&A: The slow cookers. The response was that we were using the gamma-to-neutron 

ratio and that will effectively manage the slow cooker, so that if there is a gamma dose, we are 

adding a component of neutron to take care of that. My question on this one is still, are we 

saying that anyone that was exposed to a slow cooker was wearing a dosimeter in the first place? 

Because the implication there is that they are. 

ORAU: Is NIOSH going to take the lead on these? How are we doing that? 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

166 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

NIOSH: What we will do is to have the ORAU person respond if they know. If there is 

someone else who can add any thing of value, then they can just chime in. If we can’t answer it, 

we will just move on if they can’t add anything pertinent. Elyse, you told me that Jack Fix is 

going to be there as an external dosimetry lead and also, who else from external will be there to 

follow up on the majority of these questions? 

ORAU: Do we have a site profile person? 

ORAU: Yes, Betsy is on the line and she, as I understand it, prepared some of the original 

responses, although Jack reviewed them before we submitted them. 

ORAU: Yes, I think the easiest way would to be to let the site profile person take the lead and 

where I can add additional details, I will. Let’s do it that way. Betsy, do you have a feeling on 

this one. 

ORAU: Yes, it is unchanged from what I provided. I guess I’m not positive that anyone who 

was potentially exposed to slow cooker events was wearing a badge, but I presume that those 

with the greatest potential for exposure were badged. So, we could add some kind of qualifier, 

but I think those kind of statements are already in the site profile. I don’t think that answers the 

question exactly, but that is the best I can do. 

ORAU: I have to agree with you, Joe, that the implication is that the people who had the 

potential to be exposed were badged, and if slow cooker events occurred, and I guess there is no 

question that they did occur, that his dose would be monitored, because they were wearing a 

dosimeter. It wouldn’t be much different than during the routine for other kinds of exposures. 

SC&A: OK, I think that we can only go so far on that. I understand that, but the inference is 

there that we don’t have to worry about the neutron, because they were monitoring the gamma. 

That obviously is an assumption in that point. Let’s move on to Q.3. 

Q. 3 SC&A: Regarding the incidents, one of the things that concerns me is if there were 

various types of incidents, and presumably, the earlier you go back in history, the less likely the 

incident was going to be written up and put into the file. And so, one of the questions I have is 

the fact that if you don’t find documentation of an incident report in the individual file, doesn’t 

mean that there wasn’t one. And, one general comment that I would make is that, and this would 

go beyond K-25, is that if one plotted out just the number of incident reports per year at a 

particular facility, and see the rapid spike in incidents in a given year, it could be because they 

opened up a plant or process, or it could be that they were just documenting them better. So, I 

wondered if this has been done in the case of K-25. If you go back before 1970 or 1949, I don’t 

care what the year is, and you see that there are no incident reports, then the fact that you do not 

have an incident report in file for the individual doesn’t mean they were not exposed in an 

incident. It just means it wasn’t documented. 

ORAU: Betsy, do you have any comment on this? I guess we don’t disagree with that. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

167 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

ORAU: We use the information in the CATI. In regard to plotting the incidents in the file per 

year, I don’t know if that’s been done. 

SC&A: My thought is that it might be quite easy. I may be wrong. There might be a lot of 

years where there is a zero in the early years. In later years, it would probably be very easy. 

There may be some interim time in the 1950s and 1960s and 1970s and maybe even into the 

1980s, who knows, it might be more difficult. But it’s just the thought that it might give 

someone the picture that there were no incident reports on file for a particular year, so I would 

have to use some other approach, either told by the worker or by whomever, that there was an 

incident or that they weren’t documenting them at all at the time. 

ORAU: I’m not sure what to say. The dose reconstruction is done on a claim-by-claim basis, so 

the details of the claim are reviewed fairly extensively, and if there are implications in that claim 

that there are undocumented incidents or that there are some issues in regard to an incident, I 

think those are taken very seriously, in terms of the radiological considerations. I think that the 

incident reporting is driven by the policies and what the criteria are for an incident. But that’s a 

good point. I don’t know how easy that would be. Betsy, do you have a feel for this? I’m not 

real familiar with the K-25 facility. Is there, do you have available to you, the incident reports or 

the frequency of the incidents? 

ORAU: No, I couldn’t agree that any kind of review of incident report files would provide any 

information that would be pertinent to the individual. I couldn’t see how that would help as far a 

site profile and general information about the site or how it would help a specific individual if he 

said I was exposed to a situation where there was an airborne release and it was so many times 

the MDA or MPC or whatever. 

SC&A: I would add to that that is the particular problem, as I understand it. Workers, even 

those who do not file a claim, would potentially say, yes, I was involved in a fire back in the 

1970s. Now the dose reconstructor may not be able to find any information relative to that in the 

site profile, because it was not able to be picked up, nor any other records that he might have to 

pursue. I guess the question is, how would that be handled? 

NIOSH: This issue came up with Hanford, and is coming up with every site, and I know that the 

Board and NIOSH are collectively monitoring and tracking this kind of situation with incidents 

and how far do you look into these incidents and how well we need to document such incidents 

throughout the site. So, this particular issue is germane to a lot of the sites. Like Jack said, 

another thing is, if you look at the individual claimant’s file, and sometimes based on the type of 

incident that they may mention in their interview, you can pretty much rule out that they got 

exposed, based on their external dose and internal dose records. That’s my take on it anyways. 

SC&A: The point is that if you know that there were hundreds of incident reports documented 

per year, and someone says there was a fire that year and I got exposed, you are going to treat 

that very differently than if he says there was such an incident and there is nothing in the record 

for the whole year for anyone. You are going to treat those two cases differently in terms of how 

much you are going to dig. That’s my point; it’s a general point. It doesn’t just cover external. 

It covers all the sites and all types of exposure. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

168 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

NIOSH: Agree. 

ORAU: OK, I agree with you. If you look at some of the other sites, like the criticality incident 

at Y-12, we actually went back and there was a dose assigned to everybody that was in the 

facility. So, it is taken very seriously. If it’s a significant incident, there is quite a bit of 

evaluation that is done. 

SC&A: Right. 

ORAU: I wanted to go back to that first point, because I am gradually getting all my information 

here. Your concern about the neutron dose from the slow cookers, the site profile does include 

information that can be used in assessing a dose, a neutron dose, to the workers depending upon 

their work function that is based on a neutron-to-photon ratio. So the idea is, is to give them the 

benefit of the doubt that there could be neutrons there and that they would be assigned depending 

on the details of the specific claim. 

SC&A: True, true. 

Q.4 SC&A: The industrial radiography question response is OK. I don’t think we can take 

that any further. 

Q.5 SC&A: This involves the under-response of the dosimeters. There seems to be a sort of 

disagreement between the response and the question. The question repeats a statement regarding 

the occupational external dose in the TBD that says the under-response of the dosimeter to 

photons of less than 60 keV are “considered to be of no consequence.” So, my reading of that is 

that it says that the dosimeters possibly under-respond to photons less than 60 keV and it doesn’t 

matter. The response says the dosimeter, because of the open window, and the filter and filtered 

position would have picked everything up. So, I guess there is a disconnect between those two 

and if the response is correct, then there needs to be a statement that says that we will go back 

and change the technical basis document and that this was in error. 

ORAU: That could be a good point. Maybe we just need to check the text. As I am sure you 

realize, for this particular dosimeter, the deep dose can be estimated for lower-energy photons 

that are definitely lower than 60 keV. The significance of that is this dose is picked up in the 

open window. As you know, the open window film response way overestimated the shallow 

dose. 

SC&A: Right. 

ORAU: The people in dosimetry would be aware of what type of radiation (photon radiation) 

would be hitting the dosimeter. 

SC&A: So I guess the question is, in the technical basis document, why does it say that the 

under-response is of no consequence? 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

169 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

ORAU: I don’t know. I would not particularly pick those words, because it depends on the 

radiation found in the workplace, and that is what the author is thinking. Betsy, do you have any 

feeling on that? 

SC&A: There are two problems here; the first problem is whether or not the dosimeter underresponds or over-responds. And, of course, if it was heavily protected from contamination in 

some thick pouch or something, at some low energy of x-ray, it’s not going to be picking it up. 

But the bigger issue is that it is considered to be of no consequence. That’s the second part to it. 

OK, and that is why someone might consider that those energies are of no consequence, clearly 

when the source is inside some kind of thick sealed container or pipe. This is probably true, but 

in other cases, it may not be so. So, there were several parts to that question. At the end of the 

day, the response did not jive with the question. 

ORAU: Well, Betsy, do you have a feel for this? I’m not sure I do not agree with you. Betsy, 

do you have a feel for why the term “are of no consequence” got into the TBD? I would assume 

that it had to do with the consideration of the radiation and the workplace radiation field. 

ORAU: No. Looking at it now, I agree that we could change those words to be better. I think it 

was probably just put in, because most of the photons are greater in energy. So, it would 

probably be better to say that most of the response of the dosimeter would be to energies greater 

than 60 keV. 

SC&A: But, it’s still a bit odd, given that Jack was commenting on the over response. It’s still 

odd to have that statement that even mentions under response. So again, I don’t know why that 

was put in the technical basis document. It, to me, just raises a flag on a couple of levels; one is 

the dosimetry level itself, and the other is that someone is making a rather broad statement that 

x-rays for transuranics were never an issue or were of no consequence. So that is the two pieces 

I read there. I’m still a little puzzled by this one. It may be nothing, but I am not comfortable 

with the response. 

ORAU: This is Paul Szalinski here. I haven’t checked with the team leader on this, but I agree. 

When we get through all of these, this might be driving us to a revision, or at least a page change 

to the TBD. This is certainly one we would want to clarify. We agree with you. 

SC&A: Good, thank you. 

Q.6 SC&A: I think this is a nice point to say that they were using finger rings as early as 1949. 

So, people were thinking about these kinds of things. I mean, it’s anecdotal and it doesn’t cover 

everything, but think it is a good example, is very specific, and does give you some small, but 

some positive, sort of feeling that, yes, we are looking at these non-routine situations. So, I 

thought that was a good response. 

Q.7 SC&A: The issue of neutron dose keeps coming back. I’ll explain where I am going with 

this and that it is that there seems to be a little bit of a circular argument in everything I am 

seeing on neutron exposure. Neutron wasn’t a problem, so that we don’t have to worry about it 

and we didn’t worry about it, because it wasn’t a problem. And here, I found it was common to 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

170 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

say that the highest dose they found is someone who was there for 2,000 hours. And, by the 

way, some of these people probably worked 2,500 or even 3,000 hours in some years. But let’s 

say its 2,000 hours, that’s 10 rem without any gamma dose, internal dose, or any other dose. 

Clearly that would be significant. And, I am not saying that anyone stood there for the entire 

2,000 hours. But, it’s not 10 mrem. It’s 10 rem, a fairly significant dose. And, that’s a pretty 

big field. Yet, if the assumption is that there is not much neutron, and that you don’t need to 

monitor for it, people could have been getting 2.0 rem (1/5th of that) and you wouldn’t even 

know. So, I just felt that the upper boundary that was measured. But it is far from trivial. It’s a 

pretty big dose. And that’s assuming that we got everything right on the measurements and 

nothing was different from the past. So, I just saw a disconnect there, to say, well, we would 

have monitored people if they had a high dose, but people at the same time are saying there 

wasn’t any high dose for neutrons, so we didn’t need to monitor for it. It just seems that there is 

back to front logic there. 

ORAU: Well, I guess we could make the argument that the neutron-to-photon ratio would be 

used for anyone who was potentially exposed to neutrons. 

SC&A: Well, I guess, that we will be coming back to something on this later. So, let’s move on 

until we get back to the ratio issue later on. That may or may not answer it. But I guess the 

point is that the 10 rem a year is not a minimal potential for neutron dose. I guess, that is not 

really the highest. But nonetheless, if someone could have been in the area for a few hundred 

hours, it is far from a trivial dose, if they did this for several years. 

ORAU: I think this underscores that the problem we have in many of these site profiles is 

certainly the dosimetry, at the time, was not what was used to protect the worker. They had 

instruments, so they were aware of the radiation fields and the type of radiation. So I guess we 

agree, obviously, that 10 rem is a significant neutron dose, certainly not a trivial dose. And it 

probably wasn’t the dosimetry that led to them to whatever protective actions they took in the 

work place. 

SC&A: Are we confident that they had suitable neutron dosimetry in the workplace (I’m sorry I 

meant instrumentation) that they would have been able to measure those? There are also 

comments about the various responses in the technical basis documents that the neutron dose 

measurements were so low that they were hard to measure. I mean they are hard to measure, 

even today. And yet, if someone is in a chronic exposure situation, like .5 millirem per hour, for 

2,000 hours, we will know that that’s a rem. So I guess the question is, do we have any 

evidence, given what you have just said, that at the time, they had suitable instrumentation? 

SC&A: In our site visit when were we talking to some of the people who worked there in those 

days, there was a discussion that they had very few health physics people covering the sites, 

especially in the 1950s and 1960s. And so the likelihood that they had a lot of good 

instrumentation for that does not seem to be very likely. When they got into the 1970s and 

1980s, it started to improve, but even up until the 1990s, they indicated that their health physics 

staff didn’t really shift a lot until Bechtel Jacobs came in about 1989. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

171 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

SC&A: Yes, I just have a general sense that this is true. A lot of the comments that neutrons are 

hard to measure and that gammas were there, their instrumentation would be difficult to carry 

around, even today. So, my sense is that instruments would be lacking. I find it hard to imagine 

in the 1950s, that workers necessarily knew they were standing in a half an R field of neutrons. 

Maybe the gammas were even entirely shielded by the containers the uranium was in, or 

whatever it was, but that there was a general neutron field there. And I just haven’t seen 

anything to say that there wouldn’t have been. So anyway, I can’t go much further than that, 

other than to say I just have a sort of discomfort with the premise that people weren’t being 

exposed to significant neutron. And, we are going to come back again, in a moment, to the ratio 

issue, since I do have some questions on it. 

ORAU: I agree that is a topic that we need to examine further, but neutrons were not difficult to 

detect, they were difficult to measure. They are easy to detect. 

SC&A: Right, good point. 

SC&A: The other thing I would have to offer is that maybe it’s leaning on the words 

0.05 mSv/hr. Maybe what it needs is a qualifier to demonstrate that even if it ranged up to those 

dose rates, it wasn’t a routine circumstance. Those fields weren’t everywhere. This allows you 

to understand that you are not going to extrapolate up to 10 rem /yr. 

SC&A: Good. Let’s go to Q.8 

Q.8 SC&A: This has to do with a more technical issue pertaining to the uranium slab 

calibration for beta (which is a high-energy beta) and the question arises for Tc-99. Now, I am 

not an expert on what was going on at that site; I have read that there was Tc-99 recovery. Now, 

whether that really means that there was separation of Tc-99 I don’t know. I have tried to read 

some of the uranium mass balance documents, and so on, it is still unclear to me whether what 

people may have been exposed to Tc-99 where that was the predominant shallow dose 

contributor and not uranium. And if so, the dosimetry may have been quite erroneous. Do you 

have any thoughts about that Jack? 

ORAU: No, I guess I would like to listen to those who wrote the site profile. I agree with you 

that dosimetry calibrated with uranium is not going to measure Tc-99. Paul or Betsy, I don’t 

know if you have any thought on that. 

ORAU: I think that there are a select group of workers at the site that would be exposed to the 

Tc-99, and I think those were the cascade workers. I’m sorry I didn’t go back and read the site 

profile this morning, and the other information, so I think it would be a select group of people 

that could be exposed to the technetium. It was pretty much caught up in the cascades and I 

think, I’m not sure, only certain sections of the cascades. So it was only maintenance workers 

who were exposed. 

SC&A: I think you may recall, since you were there as part of the on site discussion; I recall the 

problem had to do with when they changed out the seals. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

172 of 191 

 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

SC&A: Yes, that was where the big problem was. 

SC&A: So again, I don’t know. If the technetium was only 10% of the overall beta dose field or 

something like that, one could just say, oh well, it’s not that significant in the overall dose 

assessment. But if there were situations where the technetium was reasonably dominant, we may 

have been missing it with the dosimetry. And yet, there is a statement in the TBD that all beta 

dose is done with uranium slab calibration. So, a lot of what I focused on was more general, but 

that is one of the sorts of technical dosimetry concerns that I recall. So maybe for some people, 

the beta dose needs to be revisited or at least it could be examined for certain job types, if there 

was significant potential for shallow dose and whether or not the dosimeter in use at the time 

would even have seen it; whether it’s just the case of modifying the shallow dose by some 

correction factor, or having to do some other assessment because you missed it entirely. So, I 

would suggest this as an action item. 

ORAU: I think use of uranium slab calibrator was pretty much the industry standard until the 

1980s. 

SC&A: Right. 

ORAU: That was when people started to use a technetium source for beta dosimetry. 

SC&A: It was considered a uranium plant. As I recall having been there and reading about it in 

the site profile, they didn’t even pick up on the technetium until the 1970s. Isn’t that right, Tom? 

SC&A: Yes, that’s about the right time. 

SC&A: And so again, I am not an expert on that plant, so if the technetium was always a trace 

contributor to the uranium field, then I think things are fine as is. If there are situations where it 

was chemically extracted, or physically extracted, in the cascade and I read that they were 

deliberately trying to extract it, for various reasons to do with the clogging of the barrier, and 

different things, if there is a situation where it became either a significant fraction, which I would 

say is 10% of 20% or more of the overall beta field, or the dominant factor, then the calibration 

may have been wrong and the dosimeter may or may not have even picked it up. 

ORAU: Yes, I’m sure we agree with you in terms of the technical aspects of this. Like you said, 

is it a significant contributor? 

SC&A: And I think that the only person who would know that is someone who understands the 

sort of the chemical engineering of the plant, and whether or not technetium was ever sort of 

isolated as a relatively pure product, or was it always in ppm inside uranium or uranium 

compound. 

ORAU: We agree with you, maybe we need to review this. There is quite a bit of discussion in 

the TBD about technetium, but whether it’s adequate, in terms of a significant potential 

exposure, we will have to check that. It certainly says right in the site profile that this is a 

potentially significant source of exposure in terms of an impurity in the recycled uranium. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

173 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Q.9 SC&A: OK. The next one sort of continues on with technetium. One of my concerns was 

that clearly, if for example, technetium was inside a steel pipe, it is not going to cause much 

trouble – no trouble from a beta and if the pipes are too thick or maybe not even from a 

bremsstrahlung problem. But, presumably, workers are going in and breaking open pipes, 

vessels, or containers, and working with exposed and diffuse sources, rather than point sources; 

extended source of beta as contamination or crud inside pipes or on filters and so on, then they 

are exposed to extended sources of beta, so the same thing applies as on the previous one. And 

then, I want to, as part of this talk about the response to item 9, it seems that item 10 and item 9 

tend to disagree with each other. If you look at the last sentence in response to item 9, it says 

Tc-99 will not produce significant bremsstrahlung radiation, due to the relatively low energy beta 

radiation emission. In the first sentence of the response to item 10, it says that the Tc-99 ... will 

provide a major source of bremsstrahlung radiation from the beta emission. So, I would suggest, 

my health physics knowledge, would say that any beta emitter can produce significant 

bremsstrahlung, even tritium, by the way, if you have enough of it. And so, it all depends upon 

the situation and nonetheless, those two responses disagree with each other completely. 

ORAU: I think we agree with you technically, but the author was thinking probably of the 

practical significance, but we can agree that we could probably look at this. We all know that we 

use shielding, that bremsstrahlung is a function of energy and atomic number of the materials. 

SC&A: Right. I think the point there is that the Tc-99 in some sort of crud buildup that 

someone may be exposed to, without a big thick steel vessel or containment around it, then the 

bremsstrahlung and the beta might be significant. I guess my point is that you can’t just dismiss 

it. 

NIOSH: We agree. 

ORAU: Well, maybe we need to look at it. I guess I still think it’s not significant. Maybe we 

need to look at quantity of technetium that would be enough to produce, and the atomic number 

of the material that would be interacting to produce, a significant bremsstrahlung. 

SC&A: Absolutely, if you have uCi quantities there, then we are wasting our time talking about 

it. I did ask that question and the reply on the amount of material was the precise amount of 

material is not known. My reply to that is that I don’t want the precise activity level, but I’m 

happy with an order of magnitude. I do know that when you look at the mass balance project, 

they are talking about thousands of curies overall of technetium being released from the site. But 

given the massive quantity of material processed through the site, this may or may not be 

significant over many years. And it still doesn’t tell me how much was not released that sort of 

went through the site. So I agree, isn’t that correct? 

ORAU: Yes. 

SC&A: That’s an important question for me and knowing how much was there. That’s where I 

started coming from. I’ve got no sense of this from any of the documents that I have read, and 

that’s part of the problem. And whether there was chemical or physical concentration of the 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

174 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

technetium – again, I still do not know when it’s concentrated, is it just detected, or was it a 

problem. The fact that it is mentioned so much makes me assume it was a problem. That’s just 

an assumption on my part. 

ORAU: You know, from an interesting perspective, the more bremsstrahlung we have the better 

off the dosimetry will be. So we agree with you that maybe we just need to tighten this up a little 

bit because the question, “is this significant,” needs to be resolved. I think the site profile tried to 

address it, but obviously, given the questions that you have, the discussion wasn’t fully 

successful. 

SC&A: It may not be a problem, but I don’t see anything that tells me it’s not a problem. 

SC&A: The aspect I would offer is that, from our visit to the site and talking to various people 

and stuff like that, it wasn’t so much an issue of ubiquitous concentration of technetium around 

the site. I think the point that Betsy made earlier was that it was a small group of workers that 

really were coming into contact with it when they were changing out the seals and the transport 

of those materials down to 1104 of 1140—wasn’t it Tom? 

SC&A: Yes, it was somewhere in those buildings. 

SC&A: They would have been the ones who that really got any significant (potentially 

significant) exposure. 

SC&A: I agree. It’s clearly not a site-wide problem, because it would have been diluted in the 

stream. It’s only in those situations where it was accidentally or deliberately concentrated (and 

by the way I get the impression it was deliberately concentrated) to remove it for various reasons 

for some places and some points. The fact that it was concentrated does not necessarily mean 

that it was a significant hazard. I think everyone is in agreement on this. 

Q.11 SC&A: Item 11, the use of the ratio of neutron-to-photon fields and the use of the 

Paducah data – the concern I had and still have is were there similarities between the two plants? 

There were clearly differences between them, especially early on when K-25 was an 

experimental facility. The enrichments were different. And also, forgetting Paducah for a 

second, K-25 over its lifetime and while using recycled uranium; with different enrichments; the 

special projects going on over the life of the plant; I don’t see where there is any documented 

justification for the 0.2 ratio to be used over time and over geography (both to be the standard 

number). It may be that it’s very conservative and already covers worse-case scenarios, but if it 

does, it doesn’t say that. It just says we are just using a 0.2. And the key question that I have for 

the site profile is that surely there would be situations where there would be a container that 

emitting some x-ray or beta/gamma or material that emits x/or beta/gamma and some neutron 

field, but the container is thick steel, as an example, and clearly attenuates most all of the 

photons, yet there is no lower atomic number present and the neutron field becomes dominant. 

And I see no discussion of that at all. I know, from my own personal experience, I have seen 

that sort of situation, where people didn’t even know there were neutron fields and the containers 

shielded the x-ray and beta/gamma. They were actually storing some of these containers in 

someone’s office and yet they were sitting in a neutron field of about 30 mrem/hr, because the 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

175 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

gamma could be successfully shielded. So, I just don’t see any support for that blanket 

assumption; although it may be valid, it may be that the 0.2 was the worst thing that was ever 

found. I didn’t find the support for that. 

ORAU: Well coming up with a good source of information, when you can’t use the facilityspecific information for a surrogate for the neutron-to-photon ratio is a challenge. Do you have 

any recommendations as to what source of information you would use? 

SC&A: Well, I guess clearly going and measuring it would help. I think there has been some 

modeling done (computer modeling), and there have been some measurements. I think those are 

certainly on the right path. And then, I think some sort of learned discussion among some 

experts would be helpful. With yellow cake, the dose would be higher if it’s empty than if it’s 

full. I think some people who know these facilities, even in the present day, could ascertain if 

there would be situations where the neutron field is significant or not and dominant in terms of 

the neutron field. My gut reaction is that there would be. I may be completely wrong on that. 

And then, the other thing is that a lot of the numbers (you know- we know how thick a number 

of these containers were or are), a lot of this could be reconstructed without too much work, in 

terms of at least relative dose rates for the photons and the neutrons. And then again, it may be 

very conservative – it may not be. My gut reaction is that it is a pretty broad brush. 

ORAU: Well, speaking for the site profile team, we can certainly look at this further. These are 

good points. We will be in Oak Ridge next week; maybe we can corner someone at the meeting 

and ask them about it (or in Knoxville). 

SC&A: Yes, well maybe again, the one that is most likely is the one where there is no 

beta/gamma to speak of, so using a ratio just doesn’t have any meaning in those situations. 

ORAU: We have seen that in fuel casks. It’s somewhat different than this, however. 

SC&A: Good. Thank you. 

Q.12-Q.15 In regards to these next few responses, I didn’t have any additional things to discuss 

other than the correction in Q.14. 

Q.16 SC&A: This was the concern (were the people with the highest likely exposure badged?) 

or was it a cross section of the workers badged, including those who were most likely to get high 

doses, intermediate and low doses? There are different reasons for doing these two approaches. 

I guess there are different reasons for doing those two approaches, of course. And one example 

that was brought up in a 1977 study, where people were stated as having routine monitoring was 

used for workers when they entered areas with the potential for exposures. I guess it comes 

down to how comfortable we are with that one report. Is that valid? I’m too new to this to know 

whether I would hang my hat on this one study or not, so I will leave that to others to decide if 

that is an adequate answer. It still leaves me with an uncomfortable feeling. You are talking 

about a big plant with many different people with lots of different managers and contractors – 

does that study really hold is my question. I don’t have any evidence that it was done in any 

other way, but I do know that people did have reasons to badge other workers other than just the 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

176 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

highest workers to get a cross section of the data and so on. Harry, I don’t know if you have 

anything to add to that? 

SC&A: No, other than I think Chuck would agree that this issue has come up at other sites. Isn’t 

that correct, Chuck. 

NIOSH: I’ve been involved at the Hanford site thus far. I’m not 100% sure whether this is true 

for other sites. Jack has sat in for other sites; perhaps he has a comment. Who would be a better 

person to ask that question to? 

SC&A: Well, in my mind, it came up often in the how they handed out dosimeters to a 

representative group. 

ORAU: Well, I think it depends a lot on who has the potential for exposure. In many cases, at 

many different sites, they have essentially monitored a sampling of workers to assess what the 

situation is. There are many instances where they have assigned dosimeters and after 3 or 5 or 

6 months, have taken the dosimeters away because there didn’t seem to be enough exposure. At 

LANL and many other sites (e.g., Iowa), this was common practice to see what the potential 

might be. For some sites where there is a significant potential for incidents for very high 

exposure, and where there were security issues, like at Hanford, there was a tendency to require 

everybody to be badged when workers entered a radiological area, it was typical to have them 

monitored. It’s very site-dependent. 

SC&A: Yes, the issue here was two-fold. First was, were people wearing a badge at all, and 

second, people who were likely to get zero or who were expected to get zero, was it likely to 

issue them badges and then use some kind of averaging or coworker type of data manipulation— 

you are always at a risk of diluting the average of those that were exposed. 

ORAU: You bet. I agree with you totally. 

SC&A: So, that’s a hard one to manage and I think that the reply that was given to the question 

was a good start in my opinion. It was one example. But I don’t know if I would hang my hat 

on that one example that covers a range from 1959 to 1974. But one of the questions is how well 

respected is that study and how thorough was it. It may be all that is needed. I just don’t know. 

ORAU: I don’t know either. One thing nice about the health effect study is that they are 

typically looking at each subject. I suppose in some cases like collective dose, such a health 

effects study is particularly meaningful. 

SC&A: Tom, I don’t remember any discussion while we were on site that any representative 

dosimetry was used, or selective dosimetry, if you will. 

SC&A: No, that didn’t seem to come out. They either had a badge or were in an area where 

they didn’t think they would need a badge. 

SC&A: Yes, I didn’t get much of an idea that they used coworker badging. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

177 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

SC&A: Yes, coworker badging, it wasn’t as predominant at K-25 as at some other sites. 

ORAU: I’m thinking that for all the documents that I have reviewed, I don’t remember seeing 

any words like that – that they were going to monitor 25% of the population and then use that. 

NIOSH: If we are going to do a dose reconstruction on a person at K-25 and they had no 

dosimetry, based on their job function, and it looked like they were potentially exposed, then you 

would assign them a coworker dose. That’s how you would pick that person up. 

ORAU: Right. 

Q.17- Q.18 SC&A: On the last couple of questions really needed, probably from our side, 

could have been edited better on my part – a couple of questions were repetitive – or were 

nibbling around the same general question on the neutron-to-photon ratio subject – we have 

already agreed we need to look at that. So Q.17 and Q.18, I don’t have anything else. So, I think 

I am done with my comments on the responses. 

SC&A: Well, that’s what we have from our end. Chuck, is there anything you want to go back 

and review or actions and follow-up, and clarifies what you are going to look into? 

Actions for Follow-up for NIOSH/ORAU from the Conference Call 

NIOSH: Let's recap and clarify what we need to follow-up on. 

(1) Ensure that areas we agreed changes were needed are updated in the next revision of the 

K-25 External Dose TBD. 

(2) Q 5 – The statement that the dosimeter doesn’t respond to < 60 KeV and then the 

response that it over responds to 60 keV. Also, the point that it is “of no consequence” 

needs clarification in the TBD. 

(3) Q.7 – TBD’s claim that ‘dose less that 0.5 mSv/hr is not significant’ needs to be 

qualified. (How much it was and what it related to) 

(4) Q8 – TBD needs to clarify the utilization of the uranium slab as a calibration source for 

potential Tc-99 exposure. (What it applied to and what it didn’t apply to) 

(5) Q.9 – Need to tighten up the Tc-99 issue relative to the concentration and the potential 

number of workers who might have been exposed to significant concentrations – 

determine certain job functions and locations that may need to be looked at further. 

(6) Q 9 and 10 – Need to tighten up the discussion about bremsstrahlung exposure. (May not 

be a problem, but there is some inconsistency that needs to be worked out between Q.9 

and Q.10.) 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

178 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

(7) Q.9 and Q.10 – TC-99 potential dose needs to be evaluated further for certain job 

functions or locations. It was agreed that certain jobs could be an issue and need to be 

reviewed. 

(8) Q11 – The neutron-to-photon ratio issue needs to be looked at. Did it come from 

Paducah? Did it come from Cardarelli‘s Portsmouth study? If you use one number, then 

the TBD needs to justify that and determine if that is the right number that can be used in 

all situations. Follow-up at the Knoxville mid-year HPS meeting was mentioned as a 

way to follow-up on this. 

NIOSH: In responses where we need to modify those, should we do that at this point, or is this 

all going to feed into the SC&A audit report? 

SC&A: Tom, we can just cover that in our report, can’t we? 

SC&A: I would think so. Yes, we will summarize these in our report. 

SC&A: It will be in the summary conclusions of our audit report and that would leave it to you 

to resolve the intended actions and updates to the External Dose TBD. The good news is that 

this has all been recorded in a conference call recording tape and in the next few hours, it will be 

available if anyone wants to review it. What will happen, Tom will be writing this up as a 

summary in our report. 

SC&A: Yes, that is correct. 

SC&A: The fact that you have agreed to make those changes will, therefore, be included in our 

report. If no one has anything else, we appreciate your attendance and involvement and we will 

get back as soon as we can on it. 

Conference Call Notes on K-25 Issue Resolution for the Occupational Medical Dose TBD, 

the K-25 Occupational Environmental Dose TBD, and the K-25 Occupational 

Internal Dose TBD 

Date: January 24, 2007 

Participants 

NIOSH: Chuck Nelson 

ORAU: Susan Winslow, Bill Thomas, Carol Berger, Liz Brackett, Jim Turner, 

Elyse Thomas 

SC&A: Harry Pettengill, Tom Bell, Eric McKamey, Bill James 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

179 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

INTRODUCTORY COMMENTS: 

SC&A: We have followed what we did before for the K-25 Conference Calls. We already have 

completed the one conference call on the K-25 External Dose TBD last week. What we hope to 

do is follow the same kind of format today for the Occupational Medical Dose TBD, the 

Environmental Dose TBD, and the Internal Dose TBD. 

If you noted when we chimed in, we are recording this conference call. The only purpose of 

recording the call is to help us recall and get down the essential points. It will be available to 

everybody who is plugged into the call, and we will make sure that information gets through to 

you. So if you want to go back at a future time in the next few days, you can listen to any of the 

conversation to clarify anything that was said and to verify points. This is something that is 

available to everybody. Then, after about a week or 10 days, it goes away. If you want to keep 

it, you will have to download it to your computer. 

The process we will follow is that we will go through the sections and the questions, and we will 

indicate from our end where the response doesn’t quite answer the question for us and ask for 

clarification and any additional questions we would like to ask. I would like to use this 

opportunity to get clarification on any lingering issues in terms of, “Is that really what we meant 

by the questions?” 

We will take the responsibility of making sure the summary notes of the call get written up. 

Now the one thing we would tell everybody, and NIOSH has already agreed, is that what SC&A 

did the last time was too much verbatim. So we are going to try to cut back and shorten these 

summary notes, so that we just hit the salient points to reduce the information coming back to 

you. We will ask for your end to turn it around as quickly as you can, because this is an 

opportunity for you to clarify anything you feel is needed. 

ORAU: We do have a question. In regards to responding to your questions and comments, do 

our comments to change the summary go back to Elyse? Who should we send our comments 

back to? 

SC&A: You will respond back to Tom and I for SC&A, and I will send them over to Chuck and 

Elyse, who will coordinate and respond from their side. 

NIOSH: As the questions come up, they will be done by discipline or section, and the ORAU 

point of contact will chime in as best they can. If I have anything to add, I will add it in. If 

anybody else might have that expertise, just jump in and add anything, as needed. 

ORAU: Bill Thomas offered to cover as many questions as possible, and where he could not, he 

will get back to Paul Szalinski, who has other commitments today, for any additional input that is 

needed and can be included in the summary. 
Effective Date: Revision No. Document No. Page No. 

May 31, 2007 0 SCA-TR-TASK1-0017 180 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

GENERAL COMMENTS AND SITE DESCRIPTION 

SC&A: In regard to the General Questions and the Site Description responses, we found in most 

of the responses we have no problem with your answers at all. We will just accept them as 

written. The only comment that we have is on item 10. The question in item 10 is “How does 

NIOSH verify the completeness and accuracy of the data provided by the K-25 site? In your 

response, you indicated that the Site Profile was developed using documents that were developed 

by K-25 and reviewed by the DOE. When available, multiple documents were referenced to 

provide consistency. The only question here, and it came up from another site as well, is that in 

the course of the SC&A review, we found that almost verbatim, the information in the TBD, had 

been written by the site contractor. Is the wording “developed by” an overstatement of who 

wrote the TBD section? 

ORAU: The technical documents reviewed were provided by the K-25 contractor. We would 

look at those and retrieve paragraphs or summarize the elements of their program in the specific 

TBDs. For K-25, they had not been in operation for some time and the people working there did 

not participate in the development of the TBD, and they did not actually write the TBD. 

SC&A: Then we accept it as written for the responses that NIOSH/ORAU has provided for 

General questions and the K-25 Site Description section of the TBD. 

OCCUPATIONAL MEDICAL DOSE (ORAUT-TKBS-0016-3) 

General: 

SC&A: We want to thank the responders for their most helpful responses. For the most part, 

they answered our questions most thoroughly. There are still some issues that we would like to 

get some clarification on, and we can address these as we go through the questions and the 

responses. 

First off, we apologize for the confusion in the Table numbers. As we were reviewing the 

Medical TBD, we were continually aware that the K-25 Medical TBD was the only TBD 

document that had not been updated in 2006. We periodically checked the update page, to 

ensure that a more current update had not been published. Our comments were sent out to you 

on November 8, 2006. We didn’t catch that an update had just been released on November 7th 

until we looked at the OCAS update page on November 9th. 

As a consequence in using Turner (2004), as I noted in our questions, the tables were in an 

appendix at the back and were titled Table 3.1-1, 3.2-1 and 3.3-1 in the earlier TBD version. 

In the Turner 2006 update version, the tables were integrated into the text of the report and were 

entitled Table 3-1, 3-2 and 3-3. For the purposes of our discussion this afternoon, we will use 

these later table designations. The contents are identical as far as we can see. 

Secondly, if the response is OK, we will just say it’s OK and to save time, we will move on to 

the next question. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

181 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Q.1 SC&A: This question had to do with any evidence found for special medical x-rays. Your 

response seems OK for the most part. However, when interviewing the medical x-ray 

department personnel we found they had medical records for all K-25 and their individual x-ray 

files on file back to 1989. They also stated that the medical records for the 1940s and 1950s 

were thought to have been microfilmed, but they did not have them available. 

In your review for special medical x-ray examinations, were you able to verify that there were no 

special medical x-rays by reviewing those microfilmed medical records? 

ORAU: We did not personally review microfilm copies of claimant medical records. We relied 

on K-25 to provide pertinent information that they had access to when we made the request for 

their records. ORAU said that in reviewing some of that data, they did see documentation of 

x-rays being taken in the 1940s and 1950s, and they had not seen any evidence of any special 

medical examinations. NIOSH acknowledged that, if data doses exist on microfilm files, and it 

can be documented that the K-25 site personnel did not forward these, this data should then be 

looked into. 

Q.2 SC&A: In this question, we were concerned that the general rule on chest x-rays done 

annually might be used by the dose reconstructor as a default without a thorough check of the 

medical record to see if information on frequency, reasons, and types of x-rays might have 

picked up additional x-rays for the claimant. Your response addressed this well by stating that 

the frequency in Table 3-1 is used unless the individual-specific frequency is known and is more 

frequent than that in Table 3-1. 

Your response indicates that, when a “best estimate” approach to the dose reconstruction is 

necessary, the approaches used are those documented in PROC-0061. This is not mentioned 

anywhere in the updated Turner 2006 TBD, nor is the use of PROC-0061 mentioned. Will this 

be added to the next update of the K-25 Medical TBD? 

NIOSH: In the next future update of the K-25 Occupational Medical Dose TBD, PROC-0061 

will be addressed and its role in DR will be explained. 

Q. 3 SC&A: This response regarding whether dose estimates for the dose delivered by each 

chest x-ray was found in the individual claimants record is OK. When we talked with a medical 

x-ray technologist, during our interview it was verified that the dose delivered was consistent 

with good practice at the time, at least as far back as 1977. 

Q.4 SC&A: The issue of the possibility of some workers who worked with uranium dust 

getting monthly x-rays (mentioned in footnote to Table 3-1 in the period from 1944 to 1945) is 

still a concern to me. Footnote b, Table 3-1, as you pointed out, also states that some workers 

got chest x-rays every few months with potential for uranium dust exposure in the 1946–1959 

time periods. We just want to make sure that your review of claimant medical records is 

thorough enough to ensure that the claimant’s file is complete with all these either monthly 

x-rays in 1944–1945 or every few months in the 1946–1959 periods, and that they are being 

included in the individual claimant’s dose reconstruction. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

182 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

ORAU: We believe that the data we received from the K-25 site does not support this, and also 

based on claimant data submitted thus far, workers were not receiving monthly x-rays, and 

ORAU has found no other documentation of monthly x-rays for workers exposed to uranium 

dust in the 1944 to 1959 timeframe. 

Q.5 SC&A: This question was related on questions 4 above and has been resolved by our 

discussion above. 

Q.6 SC&A: This is similar to questions 4 and 5 above and has been covered. 

Q.7 SC&A: This response is OK. Your assignment of an x-ray dose on an annual basis after 

1959, even though chest x-rays were no longer required for non-radiation workers, is 

conservative and claimant favorable. 

Q.8 SC&A: Your response was reassuring in that you are assigning the higher PFG doses until 

the end of 1956 in the absence of information to the contrary. This response is OK. 

Q.9 SC&A: This question also had to do with assignment of a dose similar to the dose of 

3.0 rem recommended by OTIB-0006 (Kathren and Shockley 2005) for PFG examinations. As 

the TBD points out, these were done on K-25 workers from 1944 to 1956 using the GE-KX-10 

x-ray machine. 

We were concerned that even the K-25 Medical TBD (Turner 2004) did not mention OTIB0006. Your response validates that Table 3-2 documented skin entrance kerma of 2.488 cGy for 

these early PFG x-rays used, but it is not clearly explained in the text that this was being used in 

lieu of the generic default value of 3.0 cCy for OTIB-0006. 

Even in the updated Medical TBD (Turner 2006), OTIB-0006 and PROC-0061 are neither 

mentioned in the text of the TBD nor in the Reference section. Do you plan in future updates of 

the K-25 Medical Dose TBD to better explain this, and add some discussion about OTIB-0006 

and PROC-0061 and add them to the References? 

ORAU: We did have access to near-final copies of these two documents and have already 

incorporated the pertinent procedures into the DR process for K-25 occupational medical dose. 

NIOSH: In future updates of the K-25 Occupational Medical Dose TBD, there will be some 

discussion of the use of OTIB-0006 and PROC-0061 in the K-25 DR process. 

Q.10 SC&A: Our discussion in question 9 above covered this question as well. I have only on 

additional thing to note. Our question quoted something from (Turner 2004, pg. 7) that stated, 

“The type of X-ray machine was probably recorded, so organ dose can be extracted directly from 

Table 3.3-1.” Your finding that from 1944 to 1956, 86% of the examinations were performed 

with the GE KX-10 PFG exposures was most interesting. It was reassuring to note that if the 

medical record does not identify which machine was used, the claimant-favorable assumption 

would be that it was the GE KX-10 x-ray machine. The latter part of your response, however, 

states that, “In most cases, the individual medical records don’t include information to ascertain 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

183 of 191 

 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

the type of X-ray machine used, and that the latest revision of the TBD (2006) doesn’t contain 

the statement above.” If it was your intent to remove the quote in our question, I just wanted to 

point out that it is still in (Turner 2006) in Section 3.6, page 9, middle of the first paragraph. 

SC&A: Acknowledged that the assignment of 86% of the workers receiving the GE KX-10 PFG 

dose was claimant favorable. 

Q.11 SC&A: This response of documentation to support the assumed techniques and protocols 

applied to calculate dose for K-25 is OK. 

Q.12 SC&A: This question was answered in Q.11 above. 

Q.13 SC&A: This response is OK. 

Q.14 SC&A: This response if OK. A medical x-ray technologist interviewed during our K-25 

Site visit pointed out and provided documentation that in 1977, the Westinghouse 300-mA x-ray 

machine was inspected and certified by a known, licensed and respected health physicist. 

A medical x-ray technologist at the K-25 Site pointed out that from 1987 to present, the K-25 

Medical Department has been using a Bennett D-5251 Unit with a Eureka Tube (Inovision 

Model 4000) with an automatic collimator. X-ray output is 500 mA, but it is run at 300 mA. 

ORAU: ORAU stated that, “The K-25 TBD and OTIB 0006 both assume a poorly collimated 

beam prior to 1970, and used substitute DCFs to account for this. The substitute dose conversion 

factors are chosen (and documented in ORAUT-OTIB 0006, 2003 and 2005) to include more 

organs in the primary beam than would be the case for a properly collimated beam.” 

NIOSH: Indicated they would incorporate it into the next updated K-25 Occupational Medical 

TBD. 

OCCUPATIONAL ENVIRONMENTAL DOSE (ORAUT-TKBS-0016-4) 

General: 

SC&A: We also do appreciate the responses and have very little on which to comment. 

Q.1 SC&A: Because of a generic statement about noble gases in air, we felt this is one thing 

that needs to be investigated. We are OK with the response. 

Q.2 SC&A: There were two different references in the TBD that identified americium-241 as 

a contaminant. But given the response that the major contributors are what’s included in the 

table, we can accept the response. 

NIOSH: There were two references? 

SC&A: Yes, located in two different Sections in the TBD – Section 2.2 and the other in 

Section 4.2. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

184 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Q. 3 SC&A: The response is fine. We do understand that the calculations as performed are 

OK - no problem. 

Q.4 SC&A: The only reason that I brought up the administrative area was because, in the 

section where it was written about, there is reference to it, but it wasn’t shown on the map. That 

was the only reason. Other than that, it is OK. 

Q.5 SC&A: In the TBD, it identified upwind and downwind locations, and the response 

identified the downwind location as the primary consideration. The response is OK and, if it will 

be revised, that’s fine. 

Q.6 SC&A: OK – no problems. 

Q.7 SC&A: We noted a typo, in that 75 mrem/200 hours should be 75 mrem/2,000 hours. In 

the Annual Environmental Reports for 2003 and 2004, we found the report that was previous to 

those that, let’s say a 2000 report, that has some different information. Would it be reasonable to 

assume that if a report written in 2000 made recommendations, and within 3 years those 

recommendations had been instituted, that this could lower the doses? And if that is the case, is 

this previous document important to look at? 

ORAU: Our response is if we had one document that is the 2003 report, and there are other 

documents that we could review for information, the purpose of the site profile is to summarize 

those documents as they exist. Do you know of any additional documents? Are you saying that 

the 2000 report does have a section on this? 

SC&A: There is a 2000 report written by Bechtel Jacobs, actually a Bechtel Jacobs document, 

that is an investigation done by SAIC that has to do with the doses around the cylinder yards. 

The maximum value that they found is a little bit higher than the 75 mrem/2,000 hours, and it 

does estimate a gamma-to-neutron ratio for determination of neutron dose. 

ORAU: I think it might be pertinent to provide that information. There is nothing that has come 

to light that would show what actions were taken within those 3 years that might have reduced 

the dose. We think it is important to get that document. Is that document on the Site Query 

Research Database? 

SC&A: I believe that is a document we found during our site visit at the DOE reading room or 

the K-25 library. We will send it to them. We will need to identify which one you are referring 

to. We will see if we can get NIOSH/ORAU a copy. 

ORAU: So, we would want to summarize the data that exists and provide multiple data points. 

Q.8 SC&A: The reason we brought this information up was that we looked at the Portsmouth 

Gaseous Diffusion report where it identified the 200 mrem per 2000 hours. The K-25 TBD also 

made reference to that, but used a different value. To some extent, it leads to confusion. We 

guess it’s pertinent to show that there are similar dose rates, but by putting the higher value in 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

185 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

there, we don’t know if this doesn’t cause confusion or gives the impression that we are using a 

lower dose, when in fact, there are higher doses available. The response is definitely acceptable. 

ORAU: So the observation here is that in Chapter 4, these kinds of results are consistent? 

SC&A: Right. 

Q.9 to Q.15 SC&A: We are fine with the rest of your responses. However, on Q.11, I would 

like to ascertain some additional things. We would like to better understand, in the TBD, in 

regard to environmental dose, are these planned releases always from the stacks and exhaust 

points? Is that correct? 

ORAU: Yes. 

SC&A: Then the question that we have is, Are there any releases or even unplanned releases 

that have been documented that we can show would have provided exposure to unmonitored 

workers? 

ORAU: Are you saying are we aware of any? 

SC&A: Yes. 

ORAU: We are not, but if we see any of those records, we can certainly add them in. To my 

knowledge, none of those were included or were available when the TBD was prepared. 

SC&A: We noted that the TBD does say that if additional information is found, it will be 

revised. We understand this is a very dynamic process and we appreciate that. 

ORAU: You have had a chance to review it. Is there a particular incident that you came across 

that you were looking for that was not characterized that we should add? 

SC&A: We recovered some information and reports that they had numerous releases that we 

think occurred primarily between 1980 and 1985, and we recognized that they were in buildings 

where they were breaking into process lines, but not released directly to the environment. 

OCCUPATIONAL INTERNAL DOSE (ORAUT-TKBS-0016-5) 

Q.1 SC&A asked, “Has NIOSH made any progress on analyzing the accuracy of the K-25 data 

in the database? We are talking here about the accuracy of the bioassay data. Is there any work 

on the analysis that is pending?” 

ORAU: No, we did ask Mike Mchathy, because he did the review of the Y-12 data, which is in 

the same database. We found an e-mail message that said he was going to do that. We think he 

did tell me that he did check some of the K-25 data in the coworker database – but again, this is 

in the coworker database and we don’t know if that would be the same. We believe that K-25 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

186 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

uses the same database that we have, but I don’t think that has been pursued any further, and I 

don‘t know if he is the one that would be doing it. 

ORAU: It’s not being done by the group that Paul Szalinski is directing either. So, if you want 

us to come up with a schedule and find out the status, we can work with Liz and Mike to give 

you a more specific answer. It sounds like the schedule is still pending and has not been 

finalized yet. 

ORAU: Actually, Mike Mchathy worked at K-25, so if he has a conflict of interest, he will not 

be the one to work this and I (Liz) can’t either, so we will have to find someone else to do this. 

Q.2 SC&A: Does NIOSH expect any difficulties in using the bioassay data appropriately, such 

as problems with labeling units on results with identified result units, units difficult to interpret, 

or typographical errors, etc.? It sounds like you had the Y-12 bioassay data looked at and maybe 

can infer some things. 

ORAU: We did investigate this for K-25 – again, as far as coworker is concerned, we did 

investigate what units should actually be and did come to a conclusion of what they were 

supposed to be and documented that in the coworker OTIB-0035 in July 2006. This, however, 

did not make it into the Site Profile yet. But it was investigated. We did not put it into the TBD 

update, which came out (Chapter 5) in October 2006. There is some information there that we 

can glean from this for the next update. 

SC&A: Has NIOSH identified any fecal sample data yet? 

ORAU: We don’t think there was any discussion of fecal samples or fecal sample MDAs in the 

TBD. The TBD focused mainly on urine. We would have to look and see if there is anything in 

the TBD on fecal sampling. We don’t think we used fecal sampling results in the 2004 version 

and more recently the 2006 TBD version. There were none used in the coworker study. There 

was no fecal data found in the DOE files either and we have not run into any fecal samples at all 

at K-25. 

SC&A: During the site visit, our team did find a document in 1964 or 1966 at the uranium 

recovery facility where they had very insoluble forms there, and they decided to have couple of 

years fecal monitoring—so there may be some fecal data out there, and these may have been 

combined with urine monitoring. But we don’t know how well it’s going to be retrieved. Looks 

like in-vivo sampling started up in 1964. They determined some lung retention half-times in that 

report. The report was going to be a presentation at the first IRPA Meeting in mid-1966. It was 

a fairly impressive report, discussing all the monitoring they were doing at that time at the 

uranium recovery facility at K-25. 

ORAU: Is that a report that you say you have? 

SC&A: Yes, I got the report from Kathy Robertson-DeMers. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

187 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

ORAU: Can we get a copy of that, too, so that we can add it to our Site Research Query 

Database? 

SC&A: Sure. It’s on the list. 

ORAU: Is it on the CD? 

SC&A: It’s on the list I have; I think it might be on the CD. 

SC&A: I do remember it coming up. It was an IRPA conference presentation. 

SC&A: It was more of a summary discussion of the whole program and it was obviously dealing 

with pretty insoluble forms. It was interesting to see that the in-vivo counters could provide 

information on lung retention half-times. 

Q.3–Q.5 Okay 

Q.6 SC&A: Has NIOSH found any centralized incident information systems for K-25 or 

databases listing incidents for K-25? 

ORAU: We haven’t seen such a box, but I would assume it exists. 

SC&A: Is there any system in place to efficiently find incident report information if a claimant 

identifies incidents during the CATI that they were involved in some? Have you worked on a 

method to find them? 

SC&A: Maybe a better question is, when they got their file from K-25, did it include any 

information about incidents? 

ORAU: From what we have seen so far, we don’t recall seeing information about incident 

reports for K-25 workers. If we run across a situation where an individual claimant tells us in his 

CATI that he was involved in an incident, and we do not have enough information provided in 

the record provided by the site, we can make a supplemental data request for more data to try to 

find more information. There does not seem to be incident documentation at K-25, but there is a 

system in place to pick it up. We have done that for various cases on some of these sites. 

Q.9 SC&A: This relates to the last year of recycled uranium reprocessing of spent fuel, where 

you have opted to cover from 1952–1988 inclusive. We have a question as to how you are going 

to use that data. Will the default isotopic distribution that contains the transuranic and fission 

product contaminants (Table 5.6) be your default distribution? Will it be applied for all intakes 

of uranium assessed from 1952 to 1988? 

ORAU: Yes, we are applying the recycled uranium component from Table 5-6 to each of the 

dose reconstructions, based on our uranium information that we have for all years. Our 

assumption is that once it gets there, it is still going to be there. Just because they stopped 

receiving it, doesn’t mean that it is all gone 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

188 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

ORAU: Moreover, we can’t really tell when it stopped and started, so we believe it’s claimant 

favorable to do just that. 

SC&A: What about from 1988 to the present – will you assume the same isotopic distribution? 

ORAU: That’s what we have been doing, yes. 

Q.12 SC&A: Regarding the default distribution being claimant favorable, has any additional 

source term information been found in the last couple of months that would change your 

defaults? The site interviews and document searches indicate that there may have been other 

radionuclides involved with some work at the site and higher enrichments, than the default, 

which were used at the site. 

ORAU: We don’t have any additional information as it pertains to the existing site profile. We 

think it behooves us to look at the coworker study that was issued in July, and see if there have 

been any changes that would be needed there. 

ORAU: The coworker study would refer back to the TBD for the contaminants. 

SC&A: If we are depending on the TBD, we don’t have any new information today that would 

revise Table 6 in regards to any changes to those default distributions? 

ORAU: There is an OTIB on recycled uranium that hasn’t been looked at in relation to K-25, in 

particular. They did address larger DOE facilities, so there may be more information in there. 

We don’t think that this OTIB has been published yet. It’s close to being released. It is 

supposed to address recycled uranium across the complex. 

NIOSH: So that would be one document that we could look at for the K-25 site profile and 

verify that. We can follow the publication of OTIB-0053 on recycled uranium, and once issued, 

we could re-look at Table 5-6. 

ORAU: I believe OTIB-0053 is at OCAS now, because we had it for internal review already. 

ORAU: We could look at the new OTIB document and see how it applies. This particular topic 

has been of a lot of interest. I remember when we first started working on the document for 

K-25, as we looked at distributions at Paducah, and at Portsmouth, we actually had a 

subcommittee we formed called the harmonization committee to try to come up with some 

consistent assumptions, because at each site we had headed off in different directions and Cindy 

Bloom tried to help us harmonize the three gaseous diffusion plants. 

SC&A: Good, it looks like you are making sure we get all the radionuclides involved with all 

the default distributions. 

Q.17 SC&A: This question is about which enrichment. Is NIOSH going to assume 3% 

enrichment for all U intakes identified with mass concentration bioassay data, and will not 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

189 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

consider a higher enrichment? Site documents indicate enrichments higher than 3% at certain 

buildings during certain periods – higher enrichments generally in the earlier periods. 

ORAU: We can’t speak to that question, but we can tell that most of the bioassay results are in 

terms of activity, so the enrichment doesn’t affect the outcome of the dose assessment. For the 

coworker OTIB, we only used the results that were in activity. There were some mass 

measurements done at the same time, but there were activity measurements also. 

ORAU: Yes, we are using activity. 

ORAU: And, not that we don’t have to mention enrichment, but it will have little affect on the 

dose determination. 

SC&A: At least you are aware that when you are interpreting mass concentration, that you are 

not always sure how much is there. If you just changed 3% to 4%, the dose would go up 

significantly. There were a lot of areas during different periods, especially in the early years, 

where enrichment went up to 5% or 10% or 12%. We know what you are saying, and that most 

of that period was covered by the gross alphas data – the activity measurement should be 

associated with the higher enrichment. 

ORAU: Most of the data in the early days is gross alpha. They were doing gross alpha even 

when they were doing the mass measurements, so most people have both, and we use just the 

activity measurements. 

INTERNAL DOSIMETRY COWORKER DATA FOR K-25 

Q.2 SC&A: Has NIOSH found any information on early radiological controls during the pre1948 period, or that any doses would have been significantly higher before the beginning of the 

bioassay sampling? Site document searches found some documents that describe these earlier 

years that could be interpreted as showing controls were not as advanced as in the years that 

followed this period. 

ORAU: We don’t know if anything has been found on radiological controls, but what we did 

with the coworker OTIB was to take people who started in the days before monitoring, and we 

looked at their results later on. With the slow excretion of uranium, you can take samples 

several years later, and still get a relatively reasonable picture of what their exposure has been. 

The people who started in 1945, their results in 1948 and later were no different than the other 

people who had started in 1948, and later. So it looks like the exposures were still similar over 

the whole time frame. The workers in 1945 seemed to be excreting uranium at the same level as 

those in 1948 and later. It looks like we could assume the same intake rate for each period. In 

the coworker document, it is a single intake rate for this entire early period. The urine results are 

pretty steady. It only varied up and down by a factor of 3 or so. For the whole period of 

50 years, it’s still within a factor of 3 or 4 for every year. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

190 of 191 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Actions for Follow-up for NIOSH/ORAU from the Conference Call 

K-25 Medical Dose TBD Follow-up 

(1) Q.2 – When the Medical TBD is updated, ensure that it includes a discussion of PROC0061 and OTIB-0006 (Kathren and Shockley 2005) and how it related to the dose 

reconstruction process on occupational medical dose. 

(2) Q.9 – Clarify in a future update of the Medical TBD that the OTIB-0006 procedures were 

available, pre-issuance, and have been considered in the (Turner 2006 update). Clarify 

that the Table 3-2 documentation of skin entrance kerma of 2.488 cGy for these early 

PFG x-rays was used, and that it was used in lieu of the generic default value of 3.0 cGy 

from OTIB-0006. 

(3) Q.14 – Ensure that the below information, included in the NIOSH response to Q.14, is 

added to any new updates of the K-25 Medical TBD. 

The K-25 TBD and OTIB-0006 both assume a poorly collimated beam prior to 1970, and 

use substitute DCFs to account for this. The substitute dose conversion factors are 

chosen (and documented in ORAUT-OTIB 0006, Rev. 2, 2003 and Rev. 3, 2005) to 

include more organs in the primary beam than would be the case for a properly 

collimated beam. 

K-25 Environmental Dose TBD Follow-up 

(4) Q.1 – Investigate further the possible dose potential from noble gases. 

(5) Q.4 – Review/resolve inconsistencies in the down-wind maximum ground level 

concentrations mentioned in the text vs. those shown in the map in Figure 4-1, pg. 8. 

(6) Q.7 – Correct the typographical error. 75 mrem per 200 hours should be 75 mrem/2,000 

hours. 

(7) Q.7 – SC&A to provide NIOSH with Bechtel Jacobs document regarding the 

investigation dose around the cylinder yards in regard to gamma-to-neutron ratios that is 

on the CD-ROM sent out to SC&A Team Members. 

(8) Q.8 – Make sure assumptions for potential external exposure at the Portsmouth Gaseous 

Diffusion Plant are applicable to the potential exposures at K-25. 

K-25 Internal Dose TBD Follow-up 

(9) Q.2 – SC&A to provide NIOSH with a copy of the 1966 IRPA conference presentation 

summarizing whole-body counting programs and in-vivo bioassay on insoluble uranium. 
Effective Date: 

May 31, 2007 

Revision No. 

0 

Document No. 

SCA-TR-TASK1-0017 

Page No. 

191 of 191 

 

NOTICE: This report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

(10) NIOSH is to ensure that the default isotopic distribution contained in the recycled 

transuranic and fission product contaminants (Table 5.6) for intakes of uranium assessed 

from 1952 to 1988 are consistent with OTIB-0053 when it is released. 

(11) SC&A to provide NIOSH with the overview documents CD-ROM that was developed 

from scanned documents found at K-25 during the K-25 Site visit for interviews and 

document searches. 

(12) SC&A and NIOSH to explore a way to get a copy of the hardcopy documents found 

during the document search effort at K-25 to NIOSH for scanning into PDF files and 

added to the OCAS O Drive. John Burn at NIOSH would be a point of contact to 

facilitate this. SC&A is to provide a list of the hard-copy documents that were sent the 

SC&A site visit team members at the conclusion of the site visit, so that NIOSH can 

determine the importance of capturing in PDF files what was found. 

NIOSH – In responses where we need to modify those, should we do that at this point, or is this 

all going to feed into the SC&A audit report? 

SC&A: There won’t need to be individual responses back; this will just be overviews in the 

summary of our SC&A report. SC&A will leave it to NIOSH/ORAU to resolve the intended 

actions and update the appropriate K-25 TBDs. The good news is that this has all been recorded 

in a conference call recording tape and in the next few hours, it will be available if anyone wants 

to review it. If no one has anything else, we appreciate your attendance and involvement and we 

will get back as soon as we can on it.