Draft 

ADVISORY BOARD ON 

RADIATION AND WORKER HEALTH 

National Institute for Occupational Safety and Health 

Review of the Rocky Flats Plant Special Exposure Cohort (SEC) Petition, 

SEC-00030 

Volume 1: Main Report 

Contract No. 200-2004-03805 

Task Order No. 5 

SCA-SEC-TASK5-0052

Prepared by 

S. Cohen & Associates 

1608 Spring Hill Road, Suite 400 

Vienna, Virginia 22182 

Saliant, Inc. 

5579 Catholic Church Road 

Jefferson, Maryland 21755 

April 5, 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.
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Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Document No. 

SCA-SEC-TASK5-0052, Volume 1 

Effective Date: 

Draft — April 5, 2007 

S. COHEN & ASSOCIATES:

Technical Support for the Advisory Board on 

Radiation & Worker Health Review of 

NIOSH Dose Reconstruction Program Revision No. 

0 – Draft 

Review of the Rocky Flats Plant Special 

Exposure Cohort (SEC) Petition, SEC-00030 Page 2 of 231

Task Manager: 

________________________ Date: ___________ 

Joseph Fitzgerald 

Project Manager: 

________________________ Date: ___________ 

John Mauro, PhD, CHP 

Supersedes: 

N/A 
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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 ..........................................................................................................9 

Executive Summary.......................................................................................................................15 

1.0 Summary of Principal Conclusions ...................................................................................22 

2.0 Background and Introduction ............................................................................................31 

2.1 Review Purpose .....................................................................................................31 

2.2 Review Chronology ...............................................................................................31 

2.3 Review Scope.........................................................................................................45 

3.0 High-Fired Plutonium Oxide .............................................................................................46 

3.1 Overview of Issues.................................................................................................46 

3.2 SC&A Review Methods ........................................................................................46 

3.3 SC&A Conclusions................................................................................................47 

3.4 SC&A’s Review of the Rocky Flats Lung and Urinalysis Monitoring 

Results for the Design of the High-Fired Plutonium Model..................................49 

3.5 SC&A’s Review of the Rocky Flats Lung and Urinalysis Monitoring 

Results from Five Workers Involved in the 1965 fire Whose Data were Not 

used in the Design of the High-Fired Plutonium Model........................................50 

3.6 SC&A’s Review of the Rocky Flats Urinalysis Monitoring Results from 12 

Nonclaimant Workers Involved in the 1965 Fire whose Data were not used 

in the Design of the High-Fired Plutonium Model ................................................51 

3.7 SC&A’s Review of the Rocky Flats USTUR Data for a Worker Involved in 

the 1965 Fire whose Data were not included in the HIS-20 Database ..................51 

3.8 SC&A review of the Rocky Flats Plant data from the 25 workers involved 

in the 1965 fire.......................................................................................................51 

4.0 Interpretation of External Dose Data .................................................................................53 

4.1 Introduction and Overview of Issues.....................................................................53 

4.2 SC&A’s Review Methods......................................................................................54 

4.3 Credibility and Consistency of RFP Data..............................................................54 

4.3.1 Completeness of Records for 1969 and 1970 ............................................54 

4.3.2 Problems with Gaps, No Reading, No Current Data Available, and 

Zero Entries................................................................................................70 

4.3.3 Average Worker, Not Maximum Exposed, Monitored Prior to 1964 .......76 

4.4 Data Availability and Sufficiency for Coworker Model........................................76 

4.4.1 Analysis of Data to Determine Applicability to Early Unmonitored 

Workers......................................................................................................76 

4.4.2 Use of Neutron-to-Photon Ratio Values....................................................82 

4.4.3 Evaluation of HIS-20 Database for Use in Coworker Model....................84 

4.4.4 NDRP Applicability Concerns...................................................................85 

4.5 Neutron dose data issues........................................................................................85 

4.5.1 Use of NTA Calibration for NTP Reread ..................................................85 
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4.5.2 Use of One Calibration for NTA Film Reread...........................................86 

4.5.3 NDRP Data in HIS-20 Database................................................................86 

4.6 Use and Effects of Lead Aprons ............................................................................87 

4.7 Review of Three Hypothetical Dose Reconstruction Cases..................................88 

4.7.1 Case 1—Hypothetical Neutron Dose Assignment for Monitored 

Worker, Pre-1970.......................................................................................88 

4.7.2 Case 2—Hypothetical Beta/Photon/Neutron Exposures with Use of 

Glovebox....................................................................................................89 

4.7.3 Case 3—Coworker Dose Assignment Needed for Some Years; Lead 

Apron Correction Factor Used...................................................................89 

4.7.4 Summary of Dose Reconstruction Cases...................................................90 

4.8 Specific Issues........................................................................................................90 

4.8.1 Workers’ Dosimeter Storage Location May Affect Reading ....................90 

4.8.2 Improper Control Badge Storage...............................................................90 

4.8.3 Crystals on the Floor in Building 123........................................................91 

4.8.4 Dosimetry Records from July through October 1984................................91 

4.8.5 Handling of Dense Neutron Film Results..................................................91 

4.8.6 External Dose Reconstruction Feasibility Conclusion ..............................91 

5.0 Data Integrity .....................................................................................................................93 

5.1 Safety Concerns.....................................................................................................96 

5.1.1 Background................................................................................................96 

5.1.2 Analysis......................................................................................................97 

5.1.3 Inconclusive Safety Concerns....................................................................97 

5.1.4 Safety Concerns Not Affecting the Dose Reconstruction Process ............99 

5.1.5 Processing of Lost, Damaged, Overexposed, or Otherwise 

Compromised Dosimeters........................................................................101 

5.1.6 Safety Concerns Consistent with Statements in Affidavits or Public 

Comments................................................................................................102 

5.1.7 Safety Concerns Needing Further Basis or Investigation........................104 

5.1.8 Summary..................................................................................................105 

5.2 External Dosimetry Procedures and Investigations.............................................105 

5.2.1 External Dosimetry Processing Issues.....................................................107 

5.2.2 External Dosimetry Investigations...........................................................112 

5.2.3 Summary..................................................................................................114 

5.3 Logbook Review..................................................................................................115 

5.3.1 Personnel Logbook Entries......................................................................118 

5.3.2 Other Radionuclides.................................................................................120 

5.3.3 Field Logbooks, Incidents, and Badge Destruction.................................120 

5.3.4 Field and Urinalysis Logbook Data Comparison.....................................121 

5.4 Destruction of Records ........................................................................................134 

5.5 Response to Data Integrity Examples Analysis...................................................136 

5.5.1 Background..............................................................................................136 

5.5.2 Badge Results Not Reflective of Field Exposure Conditions..................138 

5.5.3 Occurrences of Black Badges..................................................................141 
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5.5.4 Dosimeter Processing...............................................................................142 

5.5.5 Contamination Incidents..........................................................................143 

5.5.6 Exposure Geometry and Partial Body Exposure .....................................144 

5.5.7 High-Fired Plutonium Oxide ...................................................................145 

5.5.8 Destruction of Records ............................................................................147 

5.5.9 Conclusion ...............................................................................................147 

5.6 Lung Counts After the Fire..................................................................................148 

5.7 Conclusion ...........................................................................................................149 

6.0 Internal Dose Issues.........................................................................................................151 

6.1 Other Radionuclides.............................................................................................151 

6.1.1 Dosimetry Areas and Bioassay Data for other radionuclides..................152 

6.2 Americium-241....................................................................................................153 

6.2.1 Americium-241 Intake Estimation...........................................................153 

6.2.2 Plutonium Depleted in Americium-241...................................................156 

6.3 Thorium-232 ........................................................................................................157 

6.3.1 Thorium-232 Source Term ......................................................................158 

6.3.2 Estimating Thorium-232 Intakes.............................................................165 

6.4 Uranium-233 and Thorium Strikes on URANIUM-233......................................174 

6.5 Remaining Radionuclides....................................................................................176 

6.6 Review of Three Hypothetical Internal Dosimetry Dose Reconstruction 

Cases....................................................................................................................176 

6.6.1 Case 4—Hypothetical Coworker Assignment for Unmonitored 

Uranium Worker......................................................................................177 

6.6.2 Case 5—Hypothetical Assignment for Ingestion of Depleted 

Uranium ...................................................................................................177 

6.6.3 Case 6—Hypothetical Type Super S Material Assignment for 

Monitored Plutonium Worker with No Chest Counts and Positive 

Urinalysis Results....................................................................................178 

6.6.4 Summary of Dose Reconstruction Cases.................................................179 

6.7 Data Sufficiency and Application of the Internal Dose Coworker Model...........179 

6.7.1 SC&A Technical Analysis of ORAUT-OTIB-0038................................181 

6.7.2 SC&A Analysis of the Database Used by NIOSH to Derive the 

Intake Model Described in ORAUT-OTIB-0038: Comparison of 

HIS-20 versus CEDR Databases..............................................................188 

6.7.3 The unmonitored worker’s dose should be based on a model that 

ensure sufficient conservatism and provide for less uncertainty. 

Adequacy of Internal Monitoring ............................................................190 

7.0 Dose Estimation for Decontamination and Decommissioning Workers.........................192 

7.1 Background..........................................................................................................192 

7.2 SC&A Review .....................................................................................................192 

7.2.1 SC&A Review of RFP and RFETS Documents from the D&D Era.......193 

7.2.2 OCAS-TIB-0014......................................................................................196 

7.2.3 Termination Bioassay Data Comparison .................................................196 

7.2.4 Analysis of Fecal versus Lung Count Issue.............................................197 
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7.2.5 Analysis of OCAS-TIB-0014 ..................................................................199 

7.2.6 Conclusion Regarding Dose Estimation for D&D Workers....................200 

8.0 Data Completeness Evaluation ........................................................................................201 

8.1 External Dose—Random Sample ........................................................................205 

8.2 Random Sample—Internal Dose .........................................................................207 

8.3 Sample of Workers with High Cumulative Exposure..........................................207 

8.4 NIOSH Dose Reconstructions for Sampled Cases..............................................209 

8.5 Data Gaps and Coworker Models........................................................................212 

8.6 Other Issues Regarding Completeness of Dose Data ..........................................215 

8.6.1 Subcontractor Workers ............................................................................215 

8.6.2 Unbadged Prime Contractor Workers......................................................216 

8.7 Overall Conclusions Regarding Completeness....................................................216 

9.0 References........................................................................................................................218 
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LIST OF TABLES 

Table 4-1. Percent of Zero Doses Recorded for 1952–2005...................................................57 

Table 4-2. Description of Nonplutonium Buildings as Determined by 

RFP Radiological Control......................................................................................63 

Table 4-3. A Comparison of Data Sources for Claimants with 1969 Gaps ............................71 

Table 4-4. Nonplutonium Area Worker Dose for Fourth Quarter 1968 and First 

Quarter 1969 ..........................................................................................................72 

Table 4-5. Average n/p Value vs. Time Period, 1952–2005 as per ORAUT-OTIB0050, ORAUT-OTIB-0058, and NDRP ................................................................82 

Table 4-6. Average Actual Workers’ n/p Values from NIOSH’s Summary Sheet from 

RFP Neutron-to-Photon Ratios Using NDRP Data for 1953–1958 File ...............82 

Table 5-1. Exposures in Excess of 5 Rem from 1951–1984...................................................99 

Table 5-2. Individuals with Documented Dosimetry Problems during the Period from 

March 1985 through July 1986............................................................................109 

Table 5-3. Summary Results for Quantitative or Semiquantitative External Exposure 

Logbook Analysis................................................................................................125 

Table 5-4. Summary Results for Qualitative External Exposure Logbook Analysis............126 

Table 5-5. Summary Results for Internal Monitoring/Exposure Logbook Analysis............127 

Table 5-6. Postfire Bioassay for Select Individuals Interviewed after the 1969 Fire ...........148 

Table 5-7. In-vivo Counts Reported for May–December 1969 ............................................149 

Table 6-1. Methods of Analysis............................................................................................152 

Table 6-2. Time Gaps in Thorium Material Balance Data as Indicated in the Data .............160 

Table 6-3. Calculation of CDE and Annual DE Dose (in mrem)..........................................167 

Table 6-4. Excerpts from Table 10.4 of Albert (1966)—Concentrations in Breathing 

Zone Air Samples (μCi/ml) .................................................................................170 

Table 6-5. Summary of Selected Measurements Made at the Hanford Melt Plant 

Building Investigations........................................................................................172 

Table 6-6. Abrasive Operations (daily averages d/m/m3

) .....................................................173 

Table 6-7. Comparison of the Number of Samples Reported by Lochamy with the 

Number of Records Reported by Cragle..............................................................189 

Table 8-1. Percent Badged ....................................................................................................203 

Table 8-2. Rocky Flats External Dose Data Completeness Analysis—Random Samples ...205 
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LIST OF FIGURES 

Figure 4-1. Example Logbook Sheet with Zeros Followed by Arrowing Down .....................73 

Figure 4-2. Fourth Quarter 1968 Dosimetry Logsheet for Individuals on a Quarterly 

Cycle from Building 111 .......................................................................................74 

Figure 4-3. First Quarter 1969 Dosimetry Logsheet for Individuals on a Quarterly Cycle 

from Building 111..................................................................................................75 

Figure 6-1. Predicted Plutonium Bioassay Results (line) Calculated Using IMBAderived Pu Intake Rates Compared with Measured Pu-in-Urine Results 

(dots)....................................................................................................................187 

Figure 8-1. Proportion of Workers Monitored for External Dose at Rocky Flats..................204 
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ACRONYMS AND ABBREVIATIONS 

Advisory Board, Advisory Board on Radiation and Worker Health 

The Board, or 

ABRWH 

AEC U.S. Atomic Energy Commission 

AI Alveolar Interstitial 

ALARA As Low as Reasonably Achievable 

Am Americium 

AMAD Activity Medium Aerodynamic Diameter 

ANSI American National Standards Institute 

AP Anterior-Posterior 

AWE Atomic Weapons Employer 

BBO Button Break Out 

Bq Bequerel 

CA-DTPA Calcium Diethylenetriamene Pentaacetate 

CAM Continuous Air Monitor 

CATI Computer-Assisted Telephone Interview 

cc Cubic Centimeter 

CDC Centers for Disease Control and Prevention 

CDE Cumulative Dose Equivalent 

CEDE Committed Effective Dose Equivalent 

CEDR or CER Comprehensive Epidemiologic Data Resource 

CEF Critical Experiments Facility 

Cf Californium

CFR Code of Federal Regulations 

Cm Curium 

cm Centimeter 

Co Cobalt 

cpm Counts Per Minute 

Cs Cesium 

CTW Construction Trade Worker 

D&D Decontamination and Decommissioning 
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DAC Derived Air Concentration 

DCF Dose Conversion Factor 

DE Dose Equivalent 

DFRC Denver Federal Records Center 

DNFSB Defense Nuclear Facilities Safety Board 

DOE U.S. Department of Energy 

DOELAP Department of Energy Laboratory Accreditation Program 

DOL U.S. Department of Labor 

dpm Disintegrations Per Minute 

DR Dose Reconstruction 

DTPA Diethylenetriamene Pentaacetate 

DU Depleted Uranium 

EDR Extended Dose Reconstruction 

EE Energy Employee 

EEOICPA Energy Employees Occupational Illness Compensation Program Act of 2000 

ER Electro Refining 

ERDA Energy Research and Development Administration 

EU Enriched Uranium 

EXPID Exposure Identity Number 

FRC Federal Record Center 

ft Foot 

ft3

 Cubic Foot 

FY Fiscal Year 

g Gram 

GAO General Accounting Office 

GI Gastrointestinal 

GM Geometric Mean 

GMSD Geometric Mean Standard Deviation 

GSD Geometric Standard Deviation 

h, hr Hour 

HAN Hanford 

HEPA High Efficiency Particulate Air (filter) 
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HEU Highly Enriched Uranium 

HFO High-Fired Oxide 

HHS U.S. Department of Health and Human Services 

HIS Health Physics Information System

HP Health Physics 

HPERER Health Physics External Radiation Exposure Report 

hr Hour 

HRA High Radiation Area 

HSDS Health Sciences Data System 

HSP Health and Safety Practices 

HTO Tritiated Water 

ICRP International Commission on Radiological Protection 

ID Identification 

IH Industrial Hygiene 

IMBA Integrated Modules for Bioassay Analysis 

in. Inch 

Ir Iridium 

IREP Interactive RadioEpidemiological Program 

JCUSC Joint Company-Union Safety Committee 

keV Kilo Electron Volt 

kg Kilogram 

KH Kaiser-Hill 

KHAP Kaiser-Hill Assessment Project 

L Liter 

LANL Los Alamos National Laboratory 

lb Pound 

LLNL Lawrence Livermore National Laboratory 

LOD Limit of Detection 

m Meter 

m3

 Cubic Meter 

MAA Material Access Area 

MBA Mass BAlance 
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MDA Minimum Detectable Activity 

MDL Minimum Detectable Level 

MeV Mega-electron Volt 

Mg Magnesium

mg Milligram 

ml Milliliter 

min Minute 

mm Millimeter 

MPBB Maximum Permissible Body Burden 

MPL Maximum Permissible Limit 

MPLB Maximum Permissible Lung Burden 

mR Milliroentgen 

mrad Millirad 

mrem Millirem 

mrep Millirep 

MSE Molten Salt Extraction 

NaI Sodium Iodide 

nCi nanoCurie 

NCRP National Council on Radiation Protection and Measurements 

NDRP Neutron Dose Reconstruction Project 

NDT Nondestructive Testing 

NIOSH National Institute for Occupational Safety and Health 

NMMSS Nuclear Materials Management and Safeguards System 

NOCTS NIOSH-OCAS Computer Tracking System 

n/p Neutron-to-Photon 

Np Neptunium 

NRC U.S. Nuclear Regulatory Commission 

NRT National Response Team 

NTA Nuclear Track A (film) 

NTP Neutron Track Plate 

NTS Nevada Test Site 

NUREG Nuclear Regulatory Commission Guidance Document 
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OCAS Office of Compensation Analysis and Support 

O-Drive OCAS Site Research Query Interface Database 

ORAU Oak Ridge Associated Universities 

ORAUT Oak Ridge Associated Universities Team 

ORISE Oak Ridge Institute of Science and Education 

OTIB ORAU Technical Information Bulletin 

Pa Protactinium 

Pb Lead 

pCi Picocurie 

PCM Personnel Contamination Monitor 

pdf Portable Document Format 

PHA Pulse Height Analysis 

Po Polonium 

POC Probability of Causation 

PPE Personal Protective Equipment 

ppm Parts Per Million 

PSZ Perimeter Security Zone 

Pu Plutonium

PuBe Plutonium Beryllium 

PuF4 Plutonium tetrafluoride 

PuO2 Plutonium Oxide 

QA Quality Assurance 

QC Quality Control 

R Roentgen 

R2 Coefficient of Determination 

R&D Research and Development 

Ra Radium

Rad Worker II Radiation Worker II 

RCA Radiological Control Area 

RCT Radiological Control Technician 

rem Roentgen Equivalent Man 

RFCAB Rocky Flats Citizens Advisory Board 
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RFETS Rocky Flats Environmental Technology Site 

RFP Rocky Flats Plant 

RGG Recommended Concentration Guide 

Rh Rhodium 

RHHB Radiological Health Handbook 

RI Rockwell International 

RMRS Rocky Mountain Remediation Services 

RPT Radiation Protection Technician 

RWP Radiation Work Permit 

SAAM Selective Alpha Air Monitor 

SC&A S. Cohen and Associates 

SEC Special Exposure Cohort 

Sr Strontium 

SRDB Site Research Database 

TBD Technical Basis Document 

TBP Tributyl Phosphate 

Th Thorium 

TIB Technical Information Bulletin 

TLD Thermoluminescent Dosimeter 

TTA Thenoyl Trifluro Acetone 

TWMA Time-Weighted Monthly Average 

Type SS Type Super S 

U Uranium 

USARF United Steelworkers of America Rocky Flats 

USTUR United States Transuranium and Uranium Registries 

USWA United Steel Workers of America 

WB Whole Body 

ZPPR Zero Power Physics Reactor 

μCi Microcurie 

μg Microgram 

μm Micrometer 
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EXECUTIVE SUMMARY 

This draft evaluation report was prepared by S. Cohen & Associates (SC&A) at the direction of 

the Advisory Board on Radiation and Worker Health (Advisory Board, the Board, or ABRWH). 

This report documents SC&A’s review of the Special Exposure Cohort (SEC) evaluation report 

prepared by the National Institute for Occupational Safety and Health (NIOSH) for the NIOSHapproved class of Rocky Flats Plant (RFP) workers for the period April 1952–February 15, 2005. 

The Energy Employees Occupational Illness Compensation Program Act of 2000 (EEOICPA) 

provides for the U.S. Department of Health and Human Services (HHS) to add certain classes of 

U.S. Department of Energy (DOE), Atomic Weapons Employer, contractor, and subcontractor 

employees to the SEC under specified conditions. The rules described in Title 42, Part 83, of the 

Code of Federal Regulations (42 CFR Part 83), Procedure for Designating Classes of Employees 

as Members of a Special Exposure Cohort Under the Energy Employees Occupational Illness 

Compensation Program Act of 2000, relate to the process for filing petitions for additions to the 

SEC and the ways in which NIOSH and its contractors will evaluate the petitions. These rules 

also specify the role that the Board plays in the process of SEC petition evaluations, which 

includes advising the Secretary of HHS whether to add a class to the SEC and providing the 

reasons for the Board recommendation. SC&A, the technical support contractor to the Board, 

was directed at the Board’s January 22–24, 2006, meeting to conduct a focused review of SEC 

issues related to the RFP SEC petition. 

On February 15, 2005, United Steelworkers of America Local 8031 submitted an SEC petition 

(USWA 2005) for all represented members, past and current, who worked at RFP between April 

1952 and February 15, 2005. As noted by NIOSH in its evaluation report (NIOSH 2006a) for 

SEC-00030 for RFP, the following information was considered sufficient to qualify the petition 

for evaluation: 

Periods of inadequate monitoring, lack of monitoring, and/or changes in 

methodology and procedures over the history of the Rocky Flats Plant which 

make accurate dose reconstruction over time impossible. Examples include: no 

routine lung counting until the late 1960s, no monitoring for neutron radiation 

prior to the late 1950s, and neutron measurements found in error until the 1970s, 

and the impossibility of accurate dose assessment for high fired oxide exposures. 

The petitioner asserted by affidavits that energy employees at RFP have either 

had their doses inaccurately reported or had unmonitored exposures.

In its qualification of SEC-00030, NIOSH expanded the petitioner-requested class to include all 

employees of DOE, DOE contractors, and subcontractors (regardless of union membership) who 

worked at RFP from April 1952 through February 2005 and who were employed for at least 250 

aggregated workdays. 

In February 2006, SC&A began its SEC evaluation review, consistent with the Board’s SEC 

evaluation criteria of January 16, 2006, and with the SEC draft review procedures being 
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discussed by the Board (since issued on June 12, 2006), and under the auspices and direction of a 

working group appointed by the Board. Starting with an identification of SEC-relevant issues 

based on SC&A’s site profile review for Rocky Flats, the working group became the forum for 

SC&A and NIOSH to exchange technical views, to surface SEC-significant issues, and to 

ascertain the relevance and importance of these issues to dose reconstruction. Following the 

issuance of NIOSH’s SEC evaluation of Petition SEC-00030 for RFP on April 7, 2006, SC&A’s 

focus shifted to reviewing the technical basis of NIOSH’s established conclusions and whether 

the scope of its evaluation was adequate and complete. 

Unlike previous SEC evaluations conducted by SC&A, RFP has more substantial individual dose 

records available over its 50-year history than other SEC petition sites reviewed to date, to the 

extent that NIOSH observed that its anticipated use of yet-to-be-completed (at the time) 

coworker models would likely be minimal (ABRWH 2006b). Therefore, the initial emphasis of 

the SC&A review centered on high-fired plutonium oxide and the integrity of the data, rather 

than data completeness, and the subsequently issued external and internal coworker technical 

information bulletins (issued on May 12 and August 3, 2006, respectively). As it became more 

evident that the Health Physics Information System 20 (HIS-20) electronic database—the 

primary RFP electronic dose record—has substantial gaps, particularly in the earlier years of 

plant operation, SC&A undertook sampling of both this database and raw dose data in the 

claimant files to ascertain whether there is a sufficient and valid basis for the derivation and use 

of the coworker models. The “data completeness” issue became particularly important as 

questions emerged regarding the extent and significance of gaps determined to exist in external 

dose records for 1969–1970 in RFP nonplutonium facilities and for neutron doses derived for the 

1950s. 

The presence of so-called high-fired or “Type Super S” plutonium oxide at Rocky Flats and its 

implications for the feasibility of dose reconstruction were a central issue in the SEC petition. 

The petitioners saw the relative insolubility of this form of plutonium and its prevalence at the 

plant, resulting from various fires and high-temperature processes, as fundamental impediments 

to sufficiently perform an accurate dose reconstruction. In response, NIOSH developed an 

approach whereby lung doses are calculated using the model outlined in Human Respiratory 

Tract Model for Radiological Protection (International Commission on Radiological Protection 

Publication 66 (ICRP 1994), together with empirically observed correction factors as described 

in ORAUT-OTIB-0049 (ORAUT 2007b), and its complementary documents (validated, in part, 

by autopsy data from the United States Transuranium and Uranium Registries (USTUR)). 

SC&A validated the NIOSH approach by reviewing the proposed methodology for its scientific 

validity and claimant-favorable bounding assumptions, as well as evaluating the 

representativeness of the model cases that form the basis of ORAUT-OTIB-0049. SC&A’s 

evaluation concluded that the empirical approach and its correction factors are claimant 

favorable, as they typically overpredict actual organ depositions of plutonium, and therefore, this 

issue does not have SEC implications. 

To validate the model cases that are the basis for the empirical derivation of ORAUT-OTIB0049, SC&A reviewed individual radiation files containing lung and urinalysis data for 25 

workers involved in the 1965 fire, the HIS-20 electronic database, data available in the claimant 
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files of six affected workers, and USTUR data from RFP workers, and compared them with the 

lung and urinalysis data used in the design cases. That review shows that the model cases 

selected are conservative and serve to bound doses from the workers involved in the 1965 fire. 

Following up on NIOSH’s indication in working group discussions of its intent to apply 

ORAUT-OTIB-0049 to all workers with plutonium intakes, SC&A also conducted confirmatory 

analyses based on historic plutonium oxide exposure scenarios at the plant. With these analyses, 

SC&A affirms that the ORAUT-OTIB-0049 model bounds early workers who may have been 

exposed to high-fired plutonium oxide before lung counting was available taking into 

consideration the qualifying issues discussed in this report. 

Many of the working group discussions focused on the adequacy of the radiation dose data and 

the feasibility of its use in coworker dose models that can bridge gaps in individual claimant dose 

records or estimate dose for unmonitored workers. Other deliberations focused on data integrity 

and reliability. If the radiation dose records used in individual dose reconstruction or in the 

development of coworker models are substantially incomplete, contain pervasive discrepancies, 

or show evidence of prevalent fraud, it would be infeasible “to estimate with sufficient accuracy 

the radiation dose that the class received,” a key criterion for SEC approval under 42 CFR 

Part 83. 

Since data integrity and reliability are fundamental to dose reconstruction under EEOICPA and 

for evaluations of SEC petitions, SC&A conducted extensive document searches that included 

field and urinalysis logbooks and dosimetry processing sheets, as well as in depth review of 

affidavits, and operational procedures to ascertain whether the integrity of RFP dosimetry data 

was compromised. SC&A was able to validate some of the comments provided by workers in 

the petition, during public meetings, or during interviews. Despite that, SC&A did not find 

conclusive documented evidence1

 of a systemic problem with RFP dose records. The review, 

however, raised some concerns about the validity of the dose records for workers working high 

dose rate jobs, in particular. No documentation was found pointing to a deliberate falsification 

or errant recordkeeping (other than for 1969–1970, as discussed later). 

With NIOSH relying on the original DOE-provided individual dose records for dose 

reconstruction (given acknowledged gaps in the HIS-20 database), SC&A proceeded to evaluate 

the completeness of those claimant files in a manner that would validate their completeness. 

This validation process found evidence of substantial gaps in the external and internal dose data 

for some periods and for some types of workers. NIOSH has not yet demonstrated its ability to 

fill these gaps for external dose in a manner that would produce bounding dose estimates that 

would satisfy the requirements of 42 CFR Part 83. There are also substantial gaps in internal 

1

 It should be noted that the inconclusiveness cited here stems from an investigation process directed at the 

“pervasiveness” or “systemic” nature of identified data or recordkeeping discrepancies. While the integrity of dose 

data is fundamental to reconstructing doses with “sufficient accuracy,” it was SC&A’s view, in consultation with the 

working group, that deficiencies in data integrity or completeness only rise to SEC significance when they can be 

shown to be reflective of the data or recordkeeping as a whole (a “pattern” of occurrence), as opposed to isolated 

and unrelated instances, and can be corroborated. In some cases, the results of the sampling itself have proven 

inconclusive or the level of corroborating evidence was not judged to be sufficient as a basis for a revised SEC 

conclusion. 
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dose. However, workers with high cumulative doses do not appear to have full-year gaps; hence, 

it appears that NIOSH should be able to bound internal dose with a coworker model, provided 

that it uses the available data with due attention to job types. 

A related issue involves external dose records for 1969–1970. Based on petitioner comments 

regarding improper assignment of zeros in worker dose records, SC&A examined annual dose 

records, year-by-year, and found that for some years, a higher proportion of zeros was recorded, 

an apparent anomaly most prominent for the 1969–1970 period. When SC&A raised this issue 

with NIOSH, a number of possible explanations were explored. An explanation involving a 

change in badging policy was identified as the most credible main explanation. Documentation 

exists confirming that RFP decided, in early 1969, prior to the fire, not to read quarterly badges 

in nonplutonium areas for workers with low exposure potential (apparently accepting that badges 

could be read, as needed, if any exposure incidents occurred). The unread badges were discarded 

after a few weeks. Though there is circumstantial evidence that the policy had ended by the 

close of 1970, there remains some uncertainty about when this policy ended or whether this 

practice (regardless of a sanctioning policy) may have predated or postdated 1969 and 1970, 

respectively. SC&A has concluded that this practice has significantly compromised the integrity 

of at least a portion of the 1969 and 1970 external dose record. SC&A concurs with NIOSH’s 

position at a recent Advisory Board working group meeting, during which an agency official 

characterized the zeros entered for the unread badges as “bad data” and suggested that affected 

workers be considered “unmonitored” with no recorded dose for the time periods involved 

(ABRWH 2007). As with the broader data completeness issue, SC&A concludes that an effort 

needs to be made by NIOSH to amend or construct coworker models to adequately bound the 

dose for workers affected by these gaps in their dosimetry records. 

 

SC&A examined both the Internal Dosimetry Coworker Data for Rocky Flats Environmental 

Technology Site, ORAUT-OTIB-0038 (Arno et al. 2006), and External Coworker Dosimetry 

Data for the Rocky Flats Plant, ORAUT-OTIB-0058 (Smith 2006), the respective coworker 

models for internal and external dose assessment. The review addressed the overall technical 

approach used, including the respective coworker models’ scientific validity and degree of 

conservatism as it relates to the historic dose distribution being addressed. SC&A acknowledges 

the NIOSH finding that most workers at RFP have individual monitoring records in the post1960 period, and therefore, relatively few of these workers will require the use of the coworker 

data to reconstruct their dose. However, some additional work to establish the sufficiency of 

data to support the coworker models remain, notably from the standpoint of external dose 

estimation for unmonitored nonplutonium workers in the 1950s. 

For the internal dose coworker model ORAUT-OTIB-0038, SC&A supports NIOSH’s 

conceptual approach, but is concerned that the lognormal distribution depicting the monitoring 

results truncates actual high-end results recorded, and that the 50th percentile derived from the 

lognormal distribution (applied in practice) would misrepresent the excretion rates at RFP. 

Given that the uncertainties of historic worker excretion rates are large, as shown by various 

analyses presented by both NIOSH and SC&A (see Section 6.0), consideration needs to be given 

to applying a more conservative distribution or adopting a more inclusive dose bounding 
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approach in the coworker model to assure that internal doses for unmonitored workers can be 

accomplished with sufficient accuracy. 

For the external dose coworker model, SC&A likewise supports NIOSH’s conceptual approach, 

but is concerned that the recommended neutron dose values in ORAUT-OTIB-0058 (Table 7-2) 

do not sufficiently represent and/or bound the actual doses received by workers during 1952–

1958. For example, if the ORAUT-OTIB-0058 derived neutron dose for 1957 of 0.086 rem per 

year (at the 50th percentile level) is compared to the dose for the appropriate time period of 

badging for each claimant in a NIOSH provided database, RFP NP Ratios using NDRP Data for 

53–58 (NIOSH 2007d), the recommended neutron dose is much less than the recorded neutron 

dose (an average of around 80% less). This is apparently a typical result when comparing 

coworker doses to the recorded doses. NIOSH has stated that the few workers who were 

monitored for neutrons in the 1952 to 1958 period (only 20 workers were issued monitoring 

devices for most of the period) were the ones with the greatest exposure potential. However, the 

evidence in this regard is not conclusive. NIOSH has stated that despite extensive efforts, the 

NDRP was not able to validate the model on which neutron doses were assigned to those at risk 

of such exposure in the 1952 to 1958 period by any measured field data. No documentation or 

data have been located to validate or provide quantitative support for the application of the 1959 

data to the 1952–1958 period. Since the NDRP made extensive efforts to perform such a 

validation, and failed to find data, it appears that none exist. As a result, the 1952-1958 assigned 

doses to workers at risk of neutron exposure are based on an unvalidated model. 

While neither NIOSH’s original site profile nor SEC evaluation addressed worker exposures in 

the decontamination and decommissioning (D&D) era, SC&A found the extension of ORAUTOTIB-0038 [via Rocky Flats Internal Dosimetry Coworker Extension, ORAUT-OTIB-0014 

(Allen 2006b)] for unmonitored D&D workers to be acceptable (with the same proviso above of 

applying a more conservative distribution or adopting a more inclusive dose bounding approach). 

This conclusion is based on analyses conducted by NIOSH showing that the dose distributions 

for top-tier contractors and lower tier D&D subcontractors compare favorably, thereby 

permitting a common coworker model to be applied. 

In its evaluation of both the site profile and SEC characterizations, SC&A focused on whether all 

significant sources of occupational radiation are adequately addressed to assure that claimants 

are given credit for potential exposures they may have received. In its review of the RFP site 

profile, SC&A questioned the lack of characterization given potential exposures related to 

Th-232, Th-228, and other radionuclides (including Np-237, Cm-244, Am-241, and tritium) 

involved in historic secondary operations at RFP. SC&A’s assessment confirms NIOSH’s claim 

that individual dose records contained data that would allow dose reconstruction for other 

radionuclides including Np-237, Cm-244, Am-241, and tritium. While the evidence is more 

equivocal for thorium, SC&A concludes that no information has been found to contradict 

NIOSH’s source term characterizations based on available materials balance records and other 

documentation, and therefore, no SEC issue has been established with respect to the source term. 

With regard to the actual performance of thorium dose estimations, however, SC&A questions 

NIOSH’s proposed use of Air Sampling in the Workplace, NUREG-1400 (NRC 1993), a generic 
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Nuclear Regulatory Commission guidance document designed to determine the need for 

workplace air monitoring. NIOSH’s analysis has established the plausibility of using NUREG1400 to provide a general view of average working conditions. However, SC&A has 

fundamental concerns with the proposed use of NUREG-1400 to reconstruct most thorium 

exposures at Rocky Flats. SC&A finds that NIOSH has not demonstrated through its example 

NUREG-1400 calculations that these estimates are uniformly bounding, and therefore, it would 

not meet the criteria of 42 CFR 83. While alternative approaches have been discussed within the 

working group, NIOSH continues to believe NUREG-1400 is valid for application under the 

specific conditions applying to RFP. As a result, the thorium dose reconstruction matter remains 

open as an SEC issue. 

OVERALL CONCLUSION 

In general, SC&A’s issues regarding NIOSH’s SEC evaluation for RFP concern the latter’s 

ability to validate or demonstrate that it can apply its stated methods, approaches, and coworker 

models to enable “dose reconstruction with sufficient accuracy,” as prescribed by 42 CFR 

Part 83. While SC&A agrees that these methods and approaches appear to be scientifically valid 

in concept, the Advisory Board’s guidelines for SEC review requires “demonstration that it is 

feasible to reconstruct individual doses with sufficient accuracy.” There are a number of 

instances where significant concerns remain regarding the adequacy and completeness of data to 

warrant demonstration by NIOSH that it can reconstruct individual doses for all members of the 

class with sufficient accuracy. These SEC “conditional” issues have been summarized above, 

detailed in the report that follows, and can be highlighted, as follows: 

1. Where NDRP dose data is used in support of the external coworker dose model of 

ORAUT-OTIB-0058, SC&A finds that there has been no quantitative validation of 

neutron dose assignments to workers with neutron exposure potential between 1952 and 

1958. The data for such validation do not appear to exist. 

2. NIOSH has not developed approaches for bounding thorium-related doses that have been 

demonstrated as feasible and bounding. SC&A has pointed to likely avenues for 

developing such estimates, but these approaches have been rejected by NIOSH for use at 

RFP. As a result, the issue remains unresolved. 

3. NIOSH has not demonstrated that its existing coworker model (or an alternative one) 

provides a bounding dose approach that would meet the criteria of 42 CFR 83, for 

nonplutonium workers in the 1950s. 

4. The validity of the use of 1969 and 1970 external dose data for dose reconstruction is 

conditional on treating the gaps in the data (and the zeros used to fill them) as periods of 

unmonitored exposure. 

5. The use of the internal coworker model as it has been implemented in practice by NIOSH 

does not adequately reflect actual higher-end exposures experienced by monitored 
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workers at RFP. NIOSH needs to demonstrate that its model defines a valid upper bound 

based on an appropriately conservative dose distribution. 

It should be noted that these conclusions are based on information and analyses available to 

SC&A up through mid-March 2007. Resolution or near-resolution of a number of potential SEC 

issues were achieved by that time, but some require additional validation or demonstration by 

NIOSH for confirmatory reasons, as noted above and in this report, and as discussed with 

NIOSH in Advisory Board working group meetings. A supplement to this report is planned to 

address these remaining questions, in particular the neutron dose estimation issue.
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1.0 SUMMARY OF PRINCIPAL CONCLUSIONS 

The following are the principal conclusions S. Cohen and Associates (SC&A) has drawn from its 

review of the National Institute for Occupational Safety and Health (NIOSH) evaluation of 

Special Exposure Cohort (SEC) Petition 00030 (NIOSH 2006a). 

(1) SC&A conclusion regarding the feasibility of dose reconstruction for high-fired 

plutonium oxide: Based on its review of ORAUT-OTIB-0049, and relevant cases that 

are the basis of the NIOSH approach, SC&A concludes that the use of the empirical 

model and its correction factors is plausible for estimating annual dose to the lung, 

systemic organs, gastrointestinal (GI) tract organs and tissues, and extra-thoracic regions 

for intakes of Pu-239 that are retained in the lung longer than predicted by the normal 

absorption Type S model. The SC&A evaluation found the empirical approach and its 

correction factors to be claimant favorable, as they typically overpredict organ 

depositions. SC&A based its conclusion on a review of methods used by NIOSH to 

derive the lung dose adjustment factors from in vivo bioassay results and from urine 

results, as well as the adjustment factors for systemic organs, GI tract, and the extrathoracic region. SC&A also reviewed the autopsy results, the lung count data, and the 

urinary excretion data for a representative number of Rocky Flats cases. In addition, 

SC&A compared the NIOSH approach with a model recently proposed in the literature 

for exposures to high-fired plutonium oxides at Mayak Production Association, a 

plutonium production facility in the former Soviet Union. 

Based on SC&A’s review of all 25 workers involved in the 1965 fire, SC&A concludes 

that the model cases chosen by NIOSH as a basis for ORAUT-OTIB-0049 are 

sufficiently conservative for broad use. SC&A also concludes that, when used properly, 

ORAUT-OTIB-0049, together with ORAUT-OTIB-0038, and a minimum detectable 

activity (MDA) that includes some extreme conditions, can be applied to specific 

exposure scenarios at Rocky Flats Plant (RFP) in a claimant-favorable way. 

(2) SC&A conclusions regarding sufficiency and completeness of external dose data to 

support dose reconstruction with sufficient accuracy: SC&A has analyzed the issue of 

completeness of dosimetry data in U.S. Department of Energy (DOE) files, which 

NIOSH views as the primary basis for dose reconstruction for individual claimants. This 

included a random sample of 32 claimant files and a selected sample of 20 files of 

claimants who were assessed by Rocky Flats in the 1990s to have high cumulative 

exposure. SC&A’s overall conclusions for the period 1951–1992 (except 1969) are as 

follows: 

(a) There are substantial gaps in external dose data for the 1950s. The investigation of 

the high cumulative exposure cases indicates that these gaps are likely related to work 

in what was then called Plant B at RFP and some other areas not associated with 

plutonium processing facilities. 
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(b) Extensive badge data exist for Building 44, where the depleted uranium foundry was 

located. NIOSH should either show that foundry workers, or other workers who may 

have been at risk of high shallow dose, were routinely badged, or that sufficient data 

are available for this job type to fill any existing gaps in dose data. 

(c) For Plant B (mainly Building 81) workers, NIOSH has not established that backwards 

extrapolation from the early 1960s into the 1950s, when there are almost no external 

dosimetry data, provides a bounding dose approach. A suitable approach using 

appropriate data, such as area monitoring badge data and dust data, remains to be 

developed for validating the backwards extrapolation. 

(d) There are large gaps in internal dose data, notably for the 1964–1992 period, during 

which almost three-fourths of the workers had gaps of at least 1 year in internal dose 

measurements. About one-third of the cumulative years of employment had no 

measurements in the 1964–1992 period. These observations relate to the random 

sample. 

(e) The bioassay data for the highly exposed workers have essentially no gaps for full 

years. Since the internal dose data for highly exposed workers do not show annual 

gaps in any period to 1992, it is likely that one or more suitable coworker models 

designed to appropriately reflect job types and periods of employment can fill the 

gaps in internal dose (see Section 6.0 on internal dose coworker model). 

(f) SC&A has evaluated NIOSH’s claim that the dose reconstructions of almost all of the 

claimants from among the 52 evaluated suffice to demonstrate its ability to do dose 

reconstruction with sufficient accuracy under Title 42, Part 83, of the Code of Federal 

Regulations (42 CFR Part 83), Procedure for Designating Classes of Employees as 

Members of a Special Exposure Cohort Under the Energy Employees Occupational 

Illness Compensation Program Act of 2000. This regulation provides that NIOSH 

must establish “that it has access to sufficient information to estimate the maximum 

radiation dose, for every type of cancer for which radiation doses are reconstructed, 

that could have been incurred in plausible circumstances by any member of the 

class...” SC&A has concluded that the completion of these dose reconstructions itself 

does not demonstrate that “sufficient information” exists as it relates to 

42 CFR Part 83 for members of the proposed class. 

Rocky Flats has extensive dosimetry data, but there are also gaps in the data for some 

periods and some types of workers. NIOSH has not demonstrated its ability to fill 

existing data gaps for external dose in a manner that would produce bounding dose 

estimates that would satisfy the requirements of 42 CFR Part 83. SC&A found that in the 

one instance among the 50 dose reconstructions where NIOSH used the external dose 

coworker model to fill an external dose data gap for a full year, the results did not 

demonstrate NIOSH’s ability to bound the doses in the areas where gaps have been 

revealed in this evaluation. However, the availability of data means that there may be 

approaches to make bounding dose estimates. NIOSH should either develop these 
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approaches or demonstrate that the existing coworker model is bounding for the specific 

categories of workers who have gaps in their external dose records. 

(3) SC&A conclusions regarding sufficiency of neutron monitoring data for 1952–1958 to 

support dose reconstruction with sufficient accuracy: SC&A agrees with NIOSH that 

there is insufficient neutron monitoring data from 1952–1958 to create a reliable 

coworker database for use in assigning neutron doses to unmonitored workers during that 

period. Some 1952–1958 neutron dose data with individual dose identifiers (requested 

by SC&A in mid-2006), which very recently became available, allow several preliminary 

benchmark comparisons to be made. These comparisons consisted of comparing the 

measured neutron-to-proton (n/p) values to those in Table 11.1 of the Neutron Dose 

Reconstruction Project (NDRP) Report and measured neutron doses to those contained in 

Table 7-2 of ORAUT-OTIB-0058 (which were derived by using an n/p value of 1.2 from 

Table 11.1 of the NDRP Report (ORISE 2005)). In its initial investigation, SC&A found 

that the proposed coworker neutron dose was less than the measured neutron dose 25 out 

of 25 times at the 50th percentile and 6 out of 25 times at the 95th percentile level. The 

results of these comparisons indicate that the neutron dose distribution function for the 

early monitored workers (who had a high potential for neutron exposure) is not the same 

as the neutron dose distribution function derived from coworker’s data used to construct 

the tables in OTIB-0058. Page 24 of the NDRP states “The N:G building ratios were 

determined starting in 1959. For the preceding years (1952–1958), the values for 1959 

were used without modification, since no other information was available to justify 

modifying the values.” According to NIOSH (NIOSH-SC&A conference call, March 28, 

2007), no documentation and/or data has been located that will allow for the direct 

comparison of the neutron doses received during 1952-1958 to the doses that were 

assigned by the NDRP or will be assigned using the coworker data in OTIB-0058. 

This means that a validation of the coworker model cannot be performed for the 1952-

1958 period. NIOSH has stated that the monitored workers in the 1952-1958 period were 

those with the greatest potential for neutron exposure. The evidence for this assertion is 

not conclusive. For 1953, for example, the largest doses among the workers in the NDRP 

were those for monitored workers, providing evidence for the NIOSH assertion. But the 

contrary was true for some other years (especially in 1954, 1955, and 1956), when the 

highest doses were those assigned to unmonitored workers as part of the NDRP neutron 

dose reconstruction. These high-end assigned doses included workers in Building 71, 

where there was no neutron monitoring until 1957. This provides some evidence that at 

least some of the workers at risk of neutron exposure who were not monitored may have 

had higher exposure potential than those who were, if the model used to assign dose by 

the NDRP is correct. 

At this time, it is not possible to arrive at a definitive conclusion regarding the sufficiency 

of neutron data to bound dose for unmonitored workers who had the potential for neutron 

exposure in the 1952-1958 period. This may be difficult in the absence of some method 

to validate whether the assigned neutron doses are, in fact, bounding for unmonitored 

workers with a potential for neutron exposure. 
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SC&A is currently investigating the data and methods used in the NDRP Report to assign 

neutron doses during the period 1952–1958. A supplement to this report will be issued 

before the next Advisory Board meeting in early May 2007. 

(4) SC&A conclusion regarding the reliability of dose data to be used by NIOSH in dose 

reconstruction: SC&A, in its evaluation of available records (e.g., safety concerns, field 

and urinalysis logbooks, dosimetry processing information, and technical reports and 

procedures), found no conclusive evidence of systemic discrepancies or fraudulent 

records. The evaluation, however, raised concerns about the validity of the dose records 

for specific workers working high dose rate jobs, in particular. 

SC&A’s conclusion is founded on varied and extensive means of validation: (1) review 

of 49 safety concerns directly relevant to radiation protection and dosimetry; (2) review 

of over 200 urinalysis and field radiological control logbooks, (3) evaluation of data 

integrity examples, (4) investigations into dosimetry practices; and (5) investigations into 

instances of records destruction. 

Safety concerns: While these safety concerns do not directly address potential 

falsification of records, a number of interviewed petitioners had expressed a lack of 

confidence in the monitoring program as far back as 1971. SC&A reviewed NIOSH’s 

assessment of 49 selected safety concerns from among 4,946 dating from 1970–2004. 

SC&A concurs with NIOSH that no documented evidence of a systemic problem with 

radiation dose data was identified in the safety concerns reviewed that would necessarily 

preclude sufficient accuracy to dose reconstruction. 

External dosimetry procedures and investigations: SC&A conducted an evaluation of 

how doses were assigned when dosimeters or dosimeter components were lost or 

otherwise compromised. This evaluation was conducted because of the frequent mention 

in the petition of blackened film, the presence of the notations of “no data available” in 

the records, the erroneous dosimetry processing, and dosimeter contamination. NIOSH 

and other site experts have indicated that there was redundancy in the badge that would 

mitigate this situation. SC&A concurs that, in some instances, this would allow RFP to 

assign an external dose although portions of the badge were compromised. This 

redundancy did not exist when the entire dosimeter was compromised or when the site 

used film badges. SC&A only had informal assurances from RFP radiological control 

staff that dosimetry investigations were completed and questionnaires filled out. SC&A 

could find no documentation supporting the fact that these investigations were completed 

regularly prior to the mid-1980s and doses were assigned based on sound methodology. 

The existence of positive values would indicate that zeros were not the only doses 

assigned in instances where dosimeter problems were identified. This preliminary 

assessment indicates that RFP staff did not appropriately document investigations and 

appropriate dosimetry investigations may not have been conducted. Accordingly, SC&A 

was not able to verify the resulting data. 
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Data integrity examples: SC&A reviewed the NIOSH assessment of 41 examples from 

affidavits for the SEC petition, Advisory Board meeting comments from April 26, 2006 

and April 27, 2006, Advisory Board working group meetings, and discussions with 

petitioners. SC&A found no documentation pointing to deliberate falsification or errant 

recordkeeping, despite the numerous petitioners indicating that this had been the case. 

SC&A was able to validate some of the critical comments made by workers such as the 

disparity between field exposure conditions and dosimetry data, the frequent occurrence 

of incidents and fires, and inconsistencies in monitoring programs. During the review, 

questions were raised about the validity of the dose records for workers performing high 

dose rate jobs, in particular. Several references to inadequate quality assurance in the 

dosimetry program were identified throughout claimant files. 

Logbook evaluation: SC&A concurs with NIOSH’s conclusions that the comparison of 

urinalysis and field logbook data with individual health physics files demonstrates no 

indication of systemic discrepancies. Both SC&A and NIOSH had greater than 90% 

agreement between data in urinalysis and field logbooks, and data in health physics files 

for urinalysis and dosimetry data. As demonstrated by other SC&A analyses in this 

report, significant gaps were identified in Health Physics Information System 20 (HIS20) external dosimetry and urinalysis data, including positive results. SC&A observed 

that health physics files were incomplete relating to dosimetry investigations, bioassay 

for radionuclides other than plutonium and uranium, and incident reports. Given 

concerns over the initial representativeness of logbook sampling, additional reviews were 

conducted by SC&A for selected time periods and facilities. 

Destruction of records: The one particular records destruction example presented 

(T-690 trailer records) by a former RFP worker was inconclusive; however, other 

documentation indicated that there was a recommendation to discard dosimeter film from 

individuals working outside the plutonium areas. Further investigation into whether this 

did, in fact, occur should be considered by NIOSH as this film was the only legitimate 

source of dose information for many of these claims. 

(5) SC&A conclusion regarding the internal dose contribution from Th-232 and other 

secondary radionuclides: In view of the availability of bioassay data, SC&A concurs 

with NIOSH that estimation of Cm-244, Np-237, and tritium intakes is not an SEC issue. 

Am-241 does not appear to present an SEC issue given the extensive data available even 

in the earlier years (1963 onward), as well as lung counting data, whose results are likely 

to be claimant favorable and would serve to supplement bioassay data, if needed. The 

declassified materials balance data provided recently by NIOSH, as well as other 

information, broadly addressed SC&A’s concerns about the completeness of the thorium 

source term data for RFP early operational uses. 

Specific conclusions regarding the thorium source term are as follows: 

(a) There is no information in available materials balance or other data that contradicts 

NIOSH’s conclusions about thorium processing at Rocky Flats. The material balance 
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sheets are, taken as a whole, broadly consistent with NIOSH’s assumptions about the 

thorium source term. 

(b) SC&A agrees with NIOSH that the maximum amount of thorium at Rocky Flats was 

~250 kilograms. 

(c) Attribution to Normal Operating Losses was highly non-uniform. Nearly half the 

cumulative losses up to 1976 occurred in just two years, fiscal year (FY) 1964 and FY 

1967. It is noteworthy that neither was the year of the largest processing—the ingot 

canning and rolling year—1960. The available data are insufficient to establish 

whether there was much more processing than usual in FY 1964 and FY 1967 or 

whether the losses recorded in those years actually occurred earlier. 

(d) A difference of interpretation remains between NIOSH and SC&A regarding the 

magnitude and nature of the magnesium-thorium alloy source term persists due to 

contradictory interview statements and lack of documentation to resolve the large 

differences implicit in the statements made by site experts from both the Dow 

Madison and RFP sites. However, subsequent followup with RFP petitioners and 

former RFP workers produced no corroborating information to substantiate Dow 

Madison shipments of magnesium-thorium alloy to Rocky Flats, nor did 

investigations find any further information about its applications there. 

In terms of dose estimation methods, NIOSH’s analysis has established the plausibility of 

using Air Sampling in the Workplace, NUREG-1400 (U.S. Nuclear Regulatory 

Commission (NRC) 1993), to provide a general view of average working conditions. 

However, notwithstanding the availability of alternative methods, the examples provided 

to date have not validated the use of NUREG-1400 in estimating a plausible upper-bound 

dose for individual workers at Rocky Flats that would meet the criteria of 42 CFR 

Part 83. While alternative approaches have been discussed within the working group, 

NIOSH continues to believe NUREG-1400 is valid for application under the specific 

conditions applying to Rocky Flats. As a result, the thorium dose reconstruction matter 

remains open as an SEC issue. 

(6) SC&A conclusion regarding unread badge data in 1969–1970: Based on their analyses 

of the problem, SC&A and NIOSH concur that there are gaps in the 1969–1970 external 

dosimetry data for some workers. A significant part of the problem arises from the policy 

of not reading quarterly badges (with some possible exceptions) instituted in 1969. The 

termination date for the practice has not been documented, and it likely continued into 

1970. 

SC&A has concluded that the practices discussed above significantly compromised the 

integrity of at least a portion of the 1969 and 1970 dose record. During the March 7, 

2007, Advisory Board working group meeting, a NIOSH official characterized the zeros 

entered for the unread badges as “bad data” and suggested that affected workers be 
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considered “unmonitored” with no recorded dose for the time periods involved (ABRWH 

2007). SC&A concurs with this assessment. 

There are indications that the policy of not reading issued badges had stopped by the end 

of 1970. However, NIOSH cited the nonissuance of badges to some prime contractor 

employees as an explanation for the case of the secretary who had blanks in the 

dosimetry record from 1963 to 1973 (inclusive). An investigation is needed to determine 

whether badges were not issued to workers who were assessed to have low exposure 

potential or whether they were issued and not read as a matter of informal policy (which 

was then formalized in the first quarter of 1969). In either case, the dose reconstruction 

for workers with gaps outside of 1969 and 1970 should take into account that the gaps 

cannot automatically be treated as being equivalent to missed dose (i.e., a badge reading 

below the limit of detection). 

Based on SC&A’s review, it appears possible to construct coworker models to adequately 

bound the external dose for workers affected by 1969-1970 gaps in their dosimetry 

records. The existing coworker model must be demonstrated to be bounding for the 

specific times and working conditions involved. Since the practice of not reading badges 

in 1969 and 1970 was carried out primarily for a worker population similar to the one that 

was not badged earlier, it should be possible to develop appropriate methods to fill the 

gaps. With respect to the zero entries made to replace gaps, SC&A recommends that all 

zeros entered when badges were not read be dropped from the data record and the gaps be 

identified as such. 

(7) SC&A conclusions regarding internal dose issues in the coworker model: SC&A 

examined ORAUT-OTIB-0038 (Arno et al. 2006), the coworker model for internal dose 

assessment, in terms of its conceptual approach, including the overall technical approach 

used, scientific validity, and degree of conservatism. SC&A accepts NIOSH’s position 

that it is possible to derive a surrogate exposure model for the unmonitored workers 

based on the distribution of internal doses received by the monitored workers at RFP. 

However, the use of a model based on the 50th percentile of the excretion rates of the 

workers (as used in practice), in the way it was derived by NIOSH in the model, may 

misrepresent the higher exposures experienced by unmonitored workers at RFP. The 

uncertainties related to a model based on the 50th percentile excretion rates of the workers 

are large, and as a consequence, dose reconstruction cannot be accomplished with 

sufficient accuracy. 

The ORAUT-OTIB-0038 intake model was derived based on two approaches: a 

lognormal fit to the bioassay data grouped by year or quarter of a year, and an IMBA 

intake fit to the 50th percentile excretion rate from the lognormal distributions of several 

years together. The intake rates derived in ORAUT-OTIB-0038 carry uncertainties 

related to the following: 

(a) The large discrepancies between the high real results and the ones generated by the 

lognormal curves. The lognormal distribution misrepresents the RFP high-end results 
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from workers that were contaminated routinely in the course of their work, even after 

NIOSH removal of the high results from incidents and other events from the 

distribution. 

(b) The 50th percentile, used to derive the intake rates, corresponds to very low excretion 

rates and depends on the approach NIOSH uses to account for the zero values and on 

uncertainties related to the MDA values. NIOSH has not discussed or resolved the 

uncertainties related to the MDA values and their relation to the reporting levels and 

to the registered bioassay monitoring values. 

(8) SC&A conclusions regarding adequacy of internal monitoring to support dose 

reconstruction with sufficient accuracy: The petition questions the absence of lung 

counting capabilities in 1952–1964 and the contention that they were “seldom used” from 

1964–1968 (USWA 2005). NIOSH concludes in its evaluation report that “the lack of 

routine lung counting prior to the 1960s does not preclude dose reconstruction because 

urinalysis and fecal sampling results are available” (NIOSH 2006a). While NIOSH does 

not provide much detailed substantiation in the evaluation report to support this 

conclusion, SC&A agrees that RFP internal doses can be reconstructed using urinalysis 

and fecal sample results and using claimant-favorable assumptions to complement limited 

information on exposure scenarios. SC&A reviewed the issue of exposures to fire-related 

plutonium oxides in the absence of lung counting, and with very low or below MDA 

excretion results. SC&A concludes that dose reconstruction can be accomplished by the 

simultaneous use of ORAUT-OTIB-0049, the intake model from ORAUT-OTIB-0038 

based on a percentile distribution equal to or higher than the 95th percentile, the missed 

dose concept using an MDA based on the recovery extreme condition, and the 

assumption of continuous exposure between two measurements within a limited period of 

time, no longer than 1 year. (Attachment 3, Evaluation of Application to Specific RFP 

cases, Including Unmonitored Workers, prior to the Introduction of In-Vivo Counting, 

discusses this last issue in detail.) 

(9) SC&A conclusions regarding dose estimation for RFP decontamination and 

decommissioning: SC&A concurs with NIOSH’s conclusion that it is able to estimate 

doses with sufficient accuracy for the decontamination and decommissioning (D&D) era 

of plant operations based on its favorable comparison of termination bioassay data 

between “top-tier” operating contractors and identified D&D subcontractors. SC&A 

accepts the concept of applying OCAS-TIB-0014 (Olsen 2006) as an extension of 

ORAUT-OTIB-0038 for worker populations in the D&D era. However, as noted 

previously, SC&A finds that the use of a model based on the 50th percentile of the 

excretion rates of the workers would misrepresent the higher exposures experienced by 

unmonitored subcontractors at RFP. SC&A supports the use of intake models based on a 

percentile equal to or higher than the 95th. SC&A also finds OCAS-TIB-0014 incomplete 

because it does not address in-vivo counting results and the relatively large uncertainties 

associated with the calculation of doses to the lung from urine data, which are 

compounded by the complexities introduced by the different types of material 

encountered in D&D activities producing different urinary excretion patterns. However, 
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SC&A considers these latter two issues to be “site profile” in nature, i.e., not precluding 

dose reconstruction with sufficient accuracy, but bearing on the relative claimant 

favorability or technical correctness. 

(10) SC&A conclusions regarding the external coworker model: ORAUT-OTIB-0058 

generally provides reasonable dose reconstruction recommendations for assigning beta 

and photon doses to unmonitored, or under-monitored, workers at the RFP. General 

inadequacies or inconsistencies identified are “site profile” in nature, i.e., not bearing on 

dose reconstruction with sufficient accuracy, with two notable exceptions. One key 

remaining concern is that the resulting neutron doses from the data contained in Table 7-2 

are sometimes excessively low and inconsistent with those given in other RFP documents 

and data. The average n/p values used to derive Tables 7-1 and 7-2 is 0.85, whereas the 

NDRP average n/p value is around 2; n/p values from 1972 thermoluminescent dosimeter 

(TLD) data average around 1.2, and n/p values from 1977–2000 TLD readings average 

0.42. Using ORAUT-OTIB-0058 in its present form could result in some workers being 

assigned neutron doses that are significantly lower than, and not representative of, the 

doses that were actually received. This is especially true for the period when NTP/NTA 

film was used (during which neutron dosimetry data are more likely to be missing) and 

could create SEC issues unless resolved. The other issue relates to validating the existing 

external coworker model as bounding for workers in nonplutonium areas in the 1950s or, 

in the alternative, developing specific coworker approaches for those portions of the 

class.
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2.0 BACKGROUND AND INTRODUCTION 

2.1 REVIEW PURPOSE 

Under the Energy Employees Occupational Illness Compensation Program Act of 2000 

(EEOICPA) and Federal regulations defined in 42 CFR Part 82, Methods for Radiation Dose 

Reconstruction Under the Energy Employees Occupational Illness Compensation Program, 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 5 to support the Advisory Board in this effort by 

independently evaluating the RFP SEC petition review. 

On June 16, 2005, the Office of Compensation Analysis and Support (OCAS) qualified SEC 

Petition SEC-00030. The petitioner’s class definition is as follows: 

all employees of DOE, DOE contractors, or subcontractors (regardless of union 

membership) who worked at the Rocky Flats Plant (RFP) in Golden, Colorado, 

from April, 1952, through February, 2005, and who were employed for at least 

250 aggregated work days either solely under the employment or in combination 

with work days within the parameters established for other SEC classes 

(excluding aggregate work day requirements). 

The purpose of this report is to provide a review of the NIOSH evaluation report dated April 7, 

2006, for the RFP SEC Petition (SEC-00030), along with other supporting material provided by 

NIOSH during the various Advisory Board working group meetings. This supporting material 

addresses the issues raised in the SEC petition and identified by the working group as within the 

scope of the focused review of the RFP petition, as authorized by the Advisory Board. Mark 

Griffon of the Advisory Board chaired the working group, with Advisory Board members Robert 

Presley, Wanda Munn, and Michael Gibson participating. Working group sessions were 

supported by staff from NIOSH and its support contractor, Oak Ridge Associated Universities 

(ORAU), and by the Advisory Board’s technical support contractor, SC&A. 

The results in this report were developed in a series of such working group sessions, punctuated 

by issue-specific conference calls and submission of various informal issue papers and analyses. 

The overall SC&A review process has spanned the period beginning with the SC&A review of 

the NIOSH site profile for RFP in June 2005 to the present, as detailed in the chronology that 

follows. 

2.2 REVIEW CHRONOLOGY 

Key milestones of this review process are as follows: 

December 30, 2004: The Board authorized SC&A to review the RFP site profile in accordance 

with approved SC&A review procedures. 
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August 31, 2005: NIOSH and the Board issued Task Order 5, creating the contractual vehicle 

and budget to perform SEC-related investigations. 

December 8, 2005: SC&A submitted to NIOSH and the Board its review of the RFP site 

profile, which consisted of a technical review of ORAUT-TKBS-0011-1 through 0011-6 and 

supporting technical information bulletins (TIBs). 

December 13, 2005: NIOSH published an ORAU Technical Information Bulletin (OTIB) 

entitled Use of Rocky Flats Neutron Dose Reconstruction Project Data in Dose Reconstruction

(ORAUT-OTIB-0050, Rev. 00) (Smith 2005b). 

December 15, 2005: SC&A submitted to NIOSH a Draft Issue Resolution Matrix for Findings 

and Key Observations Contained in the Rocky Flats Plant Site Profile Review, Rev. 00 (SC&A 

2005c). 

January 16, 2006: The Board working group issued Report of the Working Group on Special 

Exposure Petition Review as a general framework for reviewing SEC petitions and NIOSH SEC 

petition evaluation reports. 

January 24–26, 2006: A full Board meeting was held in Oak Ridge, Tennessee. The Board 

requested that SC&A perform a focused review of selected SEC issues related to the RFP SEC 

petition and that these reviews be appropriately performed under Task Order 5. At that time, the 

Board asked SC&A to help in defining the initial scope of the focused review. 

February 7, 2006: Representatives of the Board, NIOSH, and SC&A held a conference call to 

discuss the initiation and scope of a working group review of technical issues pertinent to the 

RFP SEC petition. The working group divided the findings of the SC&A site profile review into 

five matrix issues with potential SEC implications. 

February 24, 2006: NIOSH provided preliminary responses to the RFP issue resolution matrix, 

plus new items transmitted to NIOSH and the working group by SC&A on February 21, 2006. 

In this working session, NIOSH reported that the issuance of ORAUT-OTIB-0049 was 

“imminent” and the report would provide details regarding the empirical use of autopsy data as a 

means to define an upper-bound dose estimation for high-fired plutonium oxide at RFP. The 

working group and SC&A received a briefing on this approach. Other NIOSH responses 

concerned a comment that the site profile had, in fact, adequately addressed how lung counting 

was calibrated against the Am-241 assay of the plutonium, how the NDRP (ORISE 2005) 

interpreted Nuclear Track A (NTA) film, and the overall completeness of external dose data for 

dose reconstruction. 

February 27, 2006: The working group met in Boston, Massachusetts, to discuss SEC-related 

issues for RFP. 
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March 14, 2006: A full Board conference call was held, which included the discussion of RFPrelated issues. NIOSH indicated that it had placed several new documents on the O-drive for 

Board and SC&A review. These included the following: 

• Copy of the Super S approach 

• Data for 100+ United States Transuranium and Uranium Registries (USTUR) cases 

• Spreadsheets for ORAUT-OTIB-0049 

March 21, 2006: NIOSH's written response to SC&A comments addressed issues, such as zero 

dose entries, chips falling out of TLDs, deliberately false entries, and other data reliability issues. 

SC&A submitted a memorandum to the working group regarding “Rocky Flats Data Integrity 

Issues” and provided a first draft of a consolidated list of data integrity issues for RFP, as 

suggested by the Advisory Board chairman, Dr. Ziemer. 

March 24, 2006: NIOSH provided written responses to SC&A comments, addressing issues 

such as unbadged worker exposure to neutrons, neutron energy calibration for NDRP data, and 

1970 neutron dose data. 

March 28, 2006: The working group held a meeting to discuss RFP-related SEC issues. The 

group prepared a special SEC issue resolution matrix and used it to facilitate the discussion of 

the various issues and identify action items so that NIOSH and SC&A can further evaluate the 

issues. This matrix supersedes the February 27, 2006, version. During the meeting, NIOSH 

reported on its efforts to obtain the Job-Exposure Matrix developed by Dr. Ruttenber and 

discussed its followup on a Defense Nuclear Facilities Safety Board (DNFSB) finding of the use 

of an “inappropriate” low-energy photon detector correction factor, a number of data reliability 

concerns, and the technical basis for its empirical model for high-fired plutonium oxide dose 

estimation. 

April 5, 2006: NIOSH updated written responses to SC&A comments addressing issues such as 

average isotopic assay for Am-241 (with buildup) in plutonium, zero entries in dose records 

when badges are not returned, chips falling out of TLDs, hair and body oils on TLDs, deliberate 

false entries, unauthorized work practices, workers not wearing badges in production areas, 

exposure geometry, missing dose records in areas of high exposure, length of workweek, other 

radionuclides, and completeness of dosimetry records being provided to NIOSH. 

April 5, 2006: SC&A provided a trip report following onsite SC&A interviews of petitioners. 

The report outlined data reliability concerns and proposed lines of inquiry, including the 

following: 

• Employee safety concerns 

• External dosimetry investigation processes and procedures 

• Review of field logbooks for information contradictory to dosimetry records 

• Destruction of records pertaining to personnel monitoring 

• Completeness of records provided for dose reconstruction 
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April 7, 2006: NIOSH issued the SEC Petition Evaluation Report for SEC-00030, RFP. 

April 11, 2006: The working group reissued the updated issue resolution matrix, based on 

discussions at the March 28, 2006, working group meeting and the April 5, 2006, NIOSH 

response to comments. This update supersedes the March 28, 2006, matrix. 

April 12, 2006: The working group held a conference call to continue the discussion of RFPrelated SEC issues. NIOSH provided the following documents for discussion: 

• February 27, 2006, Matrix Issues and NIOSH Responses 

• Comparison of RFP HIS-20 and Comprehensive Epidemiologic Data Resource (CEDR) 

Databases for Coworker Bioassay Assessments (Lochamy et al. 2006) 

• Follow-up Evaluation of RFP HIS-20 and CEDR Databases for Coworker Bioassay 

Assessments (Lochamy 2006) 

The working group requested that SC&A develop and submit for consideration specific actions 

to address remaining RFP data reliability issues raised in the SEC petition for NIOSH and SC&A 

followup, respectively. 

April 19, 2006: SC&A submitted to the Board and NIOSH the report Interim Evaluation of 

Data Reliability Issues: Needed Document Retrievals and Evaluations. 

April 20, 2006: The working group held a conference call, during which it discussed RFP data 

reliability issues. NIOSH provided the following documents for discussion: 

• Status of NIOSH action items 

• Independent Investigation into High-Bioassay Results, National Response Team, 

NRT-068-05, October 31, 2005 

• Coworker TIBs 

From this meeting, a revised issue resolution matrix emerged, which included the following 

issues and actions: 

• SC&A has completed its review of ORAUT-OTIB-0049, Estimating Lung Doses for 

Plutonium Strongly Retained in the Lung (ORAUT 2007b), and will include its 

conclusions regarding the feasibility of estimating doses due to intakes of so-called 

“high-fired” plutonium oxide in its evaluation report. The report will include 

consideration of GI tract doses for Super S plutonium exposures. 
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• In response to issues raised by SC&A regarding the appropriate adjustments for 

plutonium isotopic ratios and americium in-growth, NIOSH is to outline its approach for 

determining internal dose from americium. 

• NIOSH made several commitments in response to data reliability issues raised by 

petitioners, including tracking specific “no data availability” cases and reviewing its dose 

database to determine whether a systemic problem exists. SC&A provided a draft report, 

Interim Evaluation of Data Reliability Issues: Needed Document Retrieval and 

Evaluation, dated April 19, 2006 (SC&A 2006c), outlining specific data integrity issues. 

Specific NIOSH followup actions in response included (1) retrieval and review of safety 

concern reports identified by SC&A, (2) review of specific cases for 1985–1986, where 

SC&A identified discrepancies between logbooks and personnel dosimetry records, as 

well as retrieval of similar logbooks from the film and Harshaw TLD period, and 

(3) retrieval and review of secondary dosimetry, contamination control, and foreman 

logbooks to ascertain exposure information useful in validating data reliability. 

• NIOSH is reviewing or has reviewed specific data relating to SEC implications of “chips 

falling out of” TLDs, hair and body oils on TLD chips, deliberately falsified dose record 

entries, unauthorized work practices, inappropriate subtraction of background, and nonwearing of badges in production areas. On the last issue, NIOSH provided preliminary 

statistical analysis suggesting that this allegation was not a systemic problem. 

April 22, 2006: The working group reissued the updated issue resolution matrix, based on the 

April 20, 2006, working group conference call. This supersedes the April 11, 2006, matrix. 

April 25–27, 2006: The Advisory Board held a meeting in Denver, Colorado, during which it 

discussed SEC issues for RFP and received public statements regarding data reliability issues at 

RFP. The discussion raised monitoring of D&D workers as a potential issue; neither the SEC 

evaluation nor the earlier site profile characterized the adequacy of such monitoring. 

May 9, 2006: SC&A provided a transmittal of Attachment 2 of the Draft Review of the NIOSH 

Site Profile for the Rocky Flats Plant (SC&A 2006e).

May 12, 2006: NIOSH published Rev. 00 of ORAUT-OTIB-0058, entitled External Coworker 

Dosimetry Data for the Rocky Flats Plant (Smith 2006). 

May 30, 2006: The working group met to discuss the remaining SEC-focused issues for RFP. 

For discussion, SC&A provided an overall draft assessment of external dosimetry issues, 

including neutron dose estimation. SC&A also provided an updated summary and status of data 

reliability actions. 

June 14–16, 2006: The Advisory Board held a meeting in Washington, DC, during which it 

discussed SEC issues for RFP. SC&A provided a special briefing for the Board on its 

preliminary evaluation of the feasibility of estimating dose for high-fired plutonium oxide, a 

draft of which SC&A submitted to the Board and NIOSH before the meeting. 
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July 26, 2006: The working group met in Cincinnati, Ohio, to discuss remaining issues in the 

RFP SEC evaluation. The group updated the issue resolution matrix based on progress achieved 

and new issues emerging since the previous matrix. This supersedes the matrix of April 22, 

2006. NIOSH provided the following documents for discussion at the meeting: 

• Spreadsheets for HAN-1 plutonium in lung and HAN-1 urinalysis measurements 

• Kittinger logbook with accompanying notes 

• Safety concerns list for RFP (beginning in 1971) 

• Super S design case identifiers 

The revised issue resolution matrix resulting from the discussions included the following new 

actions: 

• NIOSH to provide identifiers for 25 design-basis cases (cases with highest lung burdens) 

for estimating internal dose from high-fired plutonium oxide involved in the 1965 fire 

• NIOSH to provide HIS-20 database with identifiers (name, social security number, and 

company) 

• With regards to additional baseline characterization information for “other radionuclides” 

(other than plutonium) handled at RFP, including thorium, uranium, americium, and 

curium, NIOSH to research the material accounting logs to determine the amounts on site 

and the locations where the materials would have been used 

• NIOSH to review SC&A issues regarding early neutron dose data, including use of n/p 

ratios from later time periods (1970s) for earlier periods (1950s) 

• NIOSH to review and explain potential gaps identified in RFP worker dose records for 

1969–1970 and a seemingly high number of zero readings for 1969 

• NIOSH to retrieve urinalysis logbooks for comparison to HIS-20 database for purposes of 

validating reliability of bioassay records 

• SC&A to review NIOSH statistical analysis regarding cumulative dose (April 20, 2006, 

response) as a means to resolve allegation that workers frequently were not wearing 

badges to show conformance with quarterly dose limits 

• NIOSH to provide dosimetry data and further evaluation to resolve issue of potential 

missed dose for a worker in a high-exposure area, the Stacker Receiver area of 

Building 371 

• SC&A to review NIOSH list of RFP safety concerns for 1970–2000 and determine what 

additional safety concerns (beyond the 16 already selected) should be retrieved and 

evaluated for their implications for data reliability 
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• NIOSH to post retrieved logbooks on the O-drive for working group review; NIOSH to 

sample from three different types of logs from the 1970s to 2000 for production areas of 

concern (uranium, production, and decontamination) 

• NIOSH to review Radiation Worker II (Rad Worker II) training records and site roster for 

the D&D time period and compare against HIS-20 to determine if all workers (including 

subcontractor workers) were in the RFP routine bioassay program 

• NIOSH to investigate allegation regarding missing worker exposure records in T-690 

trailer through interviews with other workers at the site at that time 

August 3, 2006: NIOSH published Rev. 00 of ORAUT-OTIB-0038, entitled Internal Coworker 

Dosimetry Data for the Rocky Flats Environmental Technology Site (Arno et al. 2006). 

August 14, 2006: NIOSH and SC&A staff held a conference call to discuss remaining issues 

surrounding application of historic n/p ratios in dose estimation for the early years. 

August 31, 2006: The working group met in Cincinnati, Ohio, to discuss the remaining issues 

regarding RFP SEC evaluation. Using the July 26 issue resolution matrix, the group discussed 

the following new actions: 

• NIOSH will spot-check back-extrapolation of n/p ratios. 

• NIOSH will review benchmarks from 1950s and 1970s for consistency and determine 

whether other “coworker” models would be appropriate. 

• Regarding SC&A issues related to ORAUT-OTIB-0058 (external coworker model), 

NIOSH agreed to (1) obtain HIS-20 data with identifiers and post on the O-drive; 

(2) recheck values in Tables 7-1 and 7-2 for 1952–1969 using NDRP data in HIS-20; (3) 

add descriptive language to ORAUT-OTIB-0050 regarding the bases for assuming that 

n/p ratios in the 1950s would be consistent with later years; (4) scrutinize NDRP 

Table 1.1 and provide additional explanation; and (5) spot-check coworker methodology 

by comparing calculated vs. measured neutron doses for 1952–1959. 

• SC&A will review and comment on the NIOSH assessment of RFP data reliability 

allegations and concerns (e.g., NIOSH’s “Data Integrity Examples” compilation). 

• NIOSH presented results of the RFP materials inventory review, which focused on “other 

radionuclides, “how much,” what “exposure potential,” “who was exposed,” and over 

what “time periods.” At the working group’s request, NIOSH agreed to schedule 

discussion of classified information associated with inventory at the upcoming Las Vegas 

meeting of the Advisory Board. 
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• SC&A questioned ORAUT-OTIB-0038 (internal coworker model); NIOSH will provide 

for SC&A review an informal “white paper” outlining the approach taken and technical 

basis. 

• NIOSH will provide comparative analysis for HIS-20 and CEDR databases; the working 

group raised a question regarding the relative completeness of the two. 

• NIOSH provided a briefing regarding the Accident Investigation Report for the 1969 fire; 

the working group commented that a crosswalk of individual data for those monitored 

during and following the fire is needed. 

• Regarding D&D, NIOSH will provide what was identified as internal self-audits of the 

RFP bioassay program and procedures governing assignment of bioassays during the 

D&D era (1993–2005). An action item still stands from the July 26 matrix that called for 

the identification of subcontractors having Rad Worker II training who would have been 

subject to routine bioassay and validation if, in fact, routine bioassays had been provided. 

September 19–21, 2006: The Advisory Board met in Las Vegas, Nevada, to discuss the status 

of the remaining SEC issues for RFP. The Board held a separate classified discussion on the 

results of NIOSH’s investigation of RFP materials ledgers for “other radionuclides.” For 

thorium, which had been of particular concern, the Board learned that all components were 

shipped from Y-12 and were mated at RFP with no significant machining and waste streams. 

For Th-228 “strikes,” three to five individuals were involved, but potential exposure was 

controlled closely; NIOSH will provide the notes from its interview with an RFP site expert. 

Other radionuclides addressed included U-236, U-237, Sr-90, curium, tritium, Po-210, and 

depleted uranium (DU). 

September 25, 2006: NIOSH reported on its investigation into the Trailer T690 records issue, 

as indicated by issue resolution matrix 36. The report provides final conclusions, based on 

interviews with 32 former RFP workers. While some individuals interviewed recalled records 

being located at this trailer, none could remember what happened to them. 

October 4, 2006: NIOSH responded to SC&A’s inquiry regarding whether any quality 

assurance (QA)/quality control (QC) or third-party reviews were done to validate the NDRP 

database. The response details the efforts made to provide such assurance at the time. 

October 19, 2006: SC&A provided to the working group and NIOSH a “sampling” evaluation it 

conducted on the claimant file data for 12 former workers selected at random for purposes of 

reviewing data reliability. Given the results, which show apparently significant gaps in many of 

the files, SC&A asked that the next working group meeting address the issue of the completeness 

of claimant files. 

October 24, 2006: SC&A responded to previous NIOSH transmittal of D&D documents in 

terms of the completeness of bioassay data to support dose estimation of D&D era workers. The 

transmittal indicates that two key findings of the audit documents provided raise concerns over 
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the completeness of bioassay records, including (1) the lack of a consistent technical basis for 

characterizing work areas as meeting derived air concentration (DAC) hour requirements for 

bioassay monitoring and (2) the high proportion of D&D workers who did not submit terminal 

bioassays. 

October 25, 2006: NIOSH provided the notes (unclassified) from an interview with a site expert 

as followup to classified discussion regarding “other radionuclides” handled historically at RFP. 

October 26, 2006: NIOSH provided a report regarding lung counts taken following the 1969 

fire. 

October 27, 2006: SC&A provided its evaluation of two NIOSH papers in a memorandum 

report, “Thorium-232 and other ‘exotic’ radionuclides at Rocky Flats—review of NIOSH 

papers.” These reviews raise concerns regarding how the source term for Th-232 was 

determined, the application of NUREG-1400 (NRC 1993) for estimating intake, consistency with 

the way Th-232 dose estimation is performed for other DOE sites, and the need for corroborating 

references to support claims made for other radionuclides. 

October 27, 2006: NIOSH completed its review of Rocky Flats logbooks for purposes of 

ascertaining data reliability and provided its results on the O-drive for working group review. 

NIOSH indicated that it “found a 96% rate of agreement between data found in various 

logbooks, and data found in the workers’ radiation files.” NIOSH concluded that there is “no 

evidence of a systematic lack of corroboration between logbooks and the individual worker 

radiation files which would cast doubt on the integrity of Rocky Flats dosimetry data, nor was 

there any evidence of inappropriate manipulation of workers’ dosimetry results.” 

October 30, 2006: NIOSH provided its Summary of Investigations Regarding 1969 Data Gap 

(NIOSH 2006m), which addresses 136 claimant files that have been identified as missing data 

for 1969. Of the 136, 35 had no external dosimetry data at all for 1969 for reasons that could not 

be readily explained. In its review, NIOSH “tested” a number of hypotheses to explain the gap, 

including “data having been lost as a result of the 1969 fire, a computer reporting problem, and 

the possibility that some badges were simply not read.” NIOSH concluded that (1) the 1969 data 

gap is much smaller than originally estimated, (2) the patterns observed in the 1969 dosimetry 

data are consistent with the administrative decision to not read film badges from employees 

stationed in nonplutonium areas with low exposure potential, and (3) a computer programming 

error may have contributed to the lack of detail in the dosimetry data (this was later corrected in 

cumulative totals). 

October 31, 2006: The Advisory Board working group provided an updated issue resolution 

matrix for the Rocky Flats SEC review. This matrix supersedes the previous one dated July 26, 

2006. 

November 1, 2006: NIOSH responded to issues raised by SC&A regarding radiation doses and 

recordkeeping during RFP’s D&D era (1993–2005). NIOSH does not concur that “any serious 
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inadequacies which would affect NIOSH’s ability to conduct dose reconstruction with sufficient 

accuracy during the D&D era have been identified.” 

November 1, 2006: NIOSH responded to SC&A’s memorandum and data spreadsheet 

questioning data completeness based on a limited sampling (12 claimant cases) of RFP dose 

records. In its case-by-case review, NIOSH responded that it does “not concur with SC&A’s 

conclusion that a review of these files indicates that ‘significant problems may exist in data 

completeness’ for the Rocky Flats records. On the contrary, [NIOSH’s] review largely 

substantiated the completeness and integrity of the records reviewed.” NIOSH intends to discuss 

the response further at the upcoming working group meeting. 

November 3, 2006: NIOSH responded to SC&A’s comments (submitted on October 27) on 

NIOSH’s written analysis of working group questions surrounding Th-232 and other “exotic” 

radionuclides at Rocky Flats. In its issue-by-issue response for discussion at the upcoming 

working group meeting, NIOSH disagreed with SC&A’s interpretation of historic operational 

information regarding thorium, reaffirmed its position regarding the applicability of NUREG1400 for estimating thorium doses at RFP, and indicated the availability of monitoring data for 

Np-237 and Cm-244. 

November 6, 2006: The Advisory Board working group for RFP SEC review met in Cincinnati, 

Ohio. The agenda included completeness of data, other radionuclides, D&D workers, logbook 

analysis, the 1969 data gap, neutron dosimetry issues, Super S, safety concerns, and data 

integrity issues. Actions stemming from the meeting included the following: 

• For “completeness of data”: SC&A to draft sampling approach to be used in sampling 

from all claimant radiation files up to 1993; NIOSH to provide access to all needed 

claimant files. 

• For “other radionuclides”: NIOSH to provide “semi-empirical” validation of thorium 

intake model (bounding intakes estimated using NUREG-1400 approach); “available 

references” regarding other radionuclide use; and September 6, 2006, Freiberg interview 

notes. SC&A to further review information regarding neptunium and curium provided by 

NIOSH. 

• For D&D: NIOSH to provide termination bioassay data, with distinction made between 

prime and subcontractors, and substantiate sufficiency of data to support coworker model 

development. 

• For logbook and 1969 data review: NIOSH to post referenced radiation files for SC&A 

validation review. 

• For neutron dosimetry issues: NIOSH and SC&A to schedule an issue-specific 

conference call to discuss status and required actions. 
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• For Super S issue: NIOSH to provide SC&A with access to needed DOE raw data to 

permit sampling and cross-comparisons of 25 model cases for ORAUT-OTIB-0049. 

• For safety concerns and data integrity issues raised in the working group review: SC&A 

to provide its written evaluation. 

November 7, 2006: NIOSH posted monthly progress reports from various RFP departments 

(e.g., Industrial Hygiene, Bioassay, and Chemistry groups) spanning from about 1954 through 

about 1971. 

November 8, 2006: NIOSH suspended existing unrestricted online access by the Advisory 

Board and SC&A to its NIOSH-OCAS Computer Tracking System (NOCTS) claimant file due 

to Privacy Act concerns. In a November 9, 2006, telephone call, Larry Elliott, NIOSH OCAS 

Director, and John Mauro, SC&A Project Director, discussed a new procedure for gaining access 

to files placed on the O-drive. In this procedure, SC&A will identify the nature of the data 

access request, the reason for the request, the people who should have access to the information, 

and the time period involved. Full SC&A access to NOCTS was restored on November 30, 

2006, with provisos for Privacy Act protections via direction from the NIOSH Contract Officer. 

November 10, 2006: Mark Griffon, Advisory Board working group chairman, distributed the 

action items from the November 6, 2006, working group meeting on the RFP SEC review. 

November 13, 2006: SC&A notified NIOSH of information provided by a site expert and 

petitioner for the Dow Madison site in Illinois, who, in public statements before the Advisory 

Board and in interviews with NIOSH, has raised the possibility of “frequent and regular” 

shipments of thorium material between Dow Madison and RFP from the 1950s through the 

1970s. 

November 20, 2006: NIOSH provided transcripts of three interviews, along with a response to 

specific issues, including the relationship between Dow Madison and Rocky Flats, origin of 

thorium at Dow Madison, and destination of material produced at Dow Madison. In its 

conclusions, NIOSH stated the following: 

[NIOSH] found no documentation of any exchange of materials between the two 

sites in a search of Rocky Flats records. The Rocky Flats materials balance 

account records do not support the receipt of truckloads of thorium metal from 

Dow Madison or anywhere else, as the maximum recorded thorium inventory was 

238 kg. We have conducted a pretty extensive search of the Rocky Flats records, 

and interviewed several former workers, and all indications point to very limited 

handling of Th at Rocky Flats. We have found no indication of “frequent and 

regular” rail shipments of thorium to Rocky Flats, and no evidence that “tons” of 

thorium were ever present at Rocky Flats. 

November 21, 2006: SC&A identified for NIOSH followup an RFP internal paper (author 

unidentified), entitled Potential Thorium Intake at RFP, which describes several quantitative 
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parameters of potential relevance to the question of the significance of thorium use, including 

production data, materials accounting, and operating losses. The questions are whether the 

source documents behind these parameters can be located and whether additional documentation 

or records exist related to this particular paper. 

November 22, 2006: NIOSH provided background on the RFP internal paper identified by 

SC&A as one written in response to alleged thorium content in offsite livestock; however, no 

source documents were located containing the quantitative data referenced in the document. 

November 27, 2006: SC&A provided an interim draft evaluation of RFP safety concerns for 

working group review. SC&A concurred with NIOSH’s assessment of many of the 49 safety 

concerns and parts of other concerns. SC&A further indicated that, “Although not providing 

definitive evidence of a systematic problem with RFP radiation dose data that would necessarily 

preclude dose reconstruction, some of them do highlight historic instances of poor quality control 

practices.” 

December 5, 2006: SC&A and NIOSH/ORAU (with the Advisory Board working group 

present) held an issue-specific conference call to discuss the status of remaining neutron 

dosimetry issues. SC&A also interviewed Roger Falk, a NIOSH site expert with extensive 

radiation program management experience at RFP, about historic dosimetry practices and 

potential data gaps. The following action items from earlier in the year were reaffirmed as 

needing a NIOSH response: 

• A revised copy of ORAUT-OTIB-0058 to reflect recent changes. 

• Microsoft Excel spreadsheets that contain the neutron data and photon data that were 

used to create Tables 7-1 and 7-2 of ORAUT-OTIB-0058. 

• An ORAUT-OTIB-0058 guide that will assist SC&A in deriving the values in Tables 7-1 

and 7-2 from the data contained in the Excel spreadsheets. 

• In the near future, scanned copies of the supervisor reports will be posted on the O-drive. 

These reports contain the data for determining the n/p values to be used to separate the 

neutron and photon doses from the composite doses for 1970–1976. 

• The results of 60–65 cases from 1952–1959, where NIOSH compares the final doses 

derived from using the coworker model to the actual measured doses. 

December 6, 2006: SC&A and NIOSH/ORAU (with the Advisory Board working group 

present) held an issue-specific conference call to discuss the remaining SC&A questions about 

ORAUT-OTIB-0038, the coworker internal dose estimation approach for RFP. Discussion 

centered on both the conceptual and technical basis for the TIB, with SC&A expressing concerns 

regarding the application of the TIB for unmonitored workers at RFP whose recorded exposures 

may not be adequately addressed, even at the 95% level distribution. NIOSH’s position is that 

this distribution is sufficiently conservative and that SC&A’s internal dose spreadsheet for 
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certain years may have been superseded (this was later established). It was concluded that there 

did not seem to be any remaining SEC-related issues with ORAUT-OTIB-0038, other than the 

review of the proposed extension for the D&D era. 

December 7, 2006: NIOSH provided the working group and SC&A with its review, Badging of 

Personnel at RFP, to address concerns over data gaps. NIOSH concludes that “Review of 

dosimetry results from three different available sources is consistent with interpretation of the 

available [RFP internal] memos, indicating that an effort in 1964 brought a significant number of 

unmonitored occasional-access personnel into the external dosimetry program and in 1974 an 

effort to bring remaining miscellaneous personnel into the external dosimetry program was 

accomplished.” 

December 8, 2006: NIOSH provided the working group and SC&A with its proposed extension 

(ORAUT-OTIB-0014) of the existing ORAUT-OTIB-0038 for RFP internal coworker data 

through the D&D era. NIOSH also indicated that it has completed an analysis of termination 

plutonium bioassay data, which demonstrates that the results for subcontractors are essentially 

identical to the results for top-tier contractors, and that it is currently working on a similar 

analysis for uranium. 

December 11–13, 2006: The Advisory Board met in Naperville, Illinois. The RFP working 

group met on December 11 to discuss the current status of RFP review issues and actions as 

outlined in the working group priority action list of November 10, 2006. Discussion centered on 

the objectives and scope of the SC&A sampling plan for data completeness that is in preparation, 

the remaining NIOSH analysis to support its position on thorium, and data comparisons between 

top-tier and D&D subcontractors. SC&A committed to submitting an interim evaluation report 

to the working group by its next meeting (January 9, 2007). 

December 19, 2006: NIOSH provided its analysis of termination bioassay results for plutonium 

and for uranium. Results are reported for (1) top-tier contractors, (2) all subcontractors, and (3) 

D&D subcontractors. The results do not show any significant differences between top-tier 

contractors and all subcontractors, or between top-tier contractors and D&D subcontractors. 

 

December 27, 2006: NIOSH issued its compendium of historic thorium source term 

information for RFP, Summary of Thorium Handling at RFP, dated December 21, 2006, by 

Brant Ulsh, Bryce Rich, and Melton Chew (Attachment 20). 

January 3–18, 2007: SC&A issued five preliminary drafts of key review sections for working 

group review and discussion. These are “Response to Data Integrity Examples Analysis” 

(January 3), “Data Completeness Evaluation” (January 10), “Other Radionuclides” (January 10), 

“Completeness of Records for 1969 and 1970” (January 11), and “Logbook Analysis” 

(January 18). These five draft reports are in addition to “Safety Concerns,” released on 

November 29, 2006. 

January 26, 2007: During the Advisory Board working group, NIOSH provided its initial 

reaction to the preliminary draft report sections provided earlier in the month by SC&A. 
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Discussions centered on clarifying questions and technical counterpoints regarding SC&A’s 

preliminary findings concerning data completeness, data reliability, thorium source terms and 

dose reconstruction, and neutron dose estimation methods. 

February 5, 2007: NIOSH publication of final version of ORAUT-OTIB-0049, Estimating 

Doses for Plutonium Strongly Retained in the Lung (ORAUT 2007b).

February 7, 2007: The Advisory Board met in Cincinnati, Ohio. The Chairman of the 

Advisory Board working group reported on the status of working group deliberations on the RFP 

SEC evaluation, with special emphasis on key issues involving completeness of data. 

February 16, 2007: SC&A briefed the Colorado congressional delegation regarding 

preliminary draft review findings. 

February 26–March 2, 2007: NIOSH provided its responses to SC&A’s preliminary draft 

report sections. 

March 7, 2007: The working group met in Cincinnati, Ohio. Discussion centered around 

SC&A’s review of NIOSH’s responses to SC&A’s preliminary draft report sections provided in 

January. The group reached some preliminary resolution on several issues associated with 

completeness of data and thorium and took final actions to enable final report preparation by 

SC&A. These actions included further validation of HIS-20 as a basis for the two coworker 

models, as well as additional information to close out actions for neutron dose estimation and 

thorium dose modeling. 

The working group also requested that SC&A conduct a sampling of records not previously 

reviewed in the “450 boxes” NIOSH referred to in its logbook evaluation report (NIOSH 2006g). 

As directed by the working group, this sampling should focus on those periods of time and those 

facilities that would afford a more “representative” sampling of available logbooks and related 

documents. The objective was to determine if specific relevant entries or data can be identified 

in these logs and to what extent these various categories of logs are “data rich” and thus 

represent a means of database validation. 

March 12–16, 2007: SC&A conducted sampling of RFP records at the DOE Legacy 

Management offices in Westminster, Colorado, and reviewed a total of 153 record sets in hard 

copy or on microfilm. Data sets were examined to determine if they included individual-specific 

dose data. SC&A found, in its limited sampling, a number of relevant logbooks containing 

useful data from the 1970s, 1980s, and 1990s. However, while these entries include individual 

identified external and internal exposure measurements for a broad range of facilities and time 

periods relevant to data validation, this new information would not change the conclusions 

reached by the previous logbook reviews. 

March 14, 2007: NIOSH provides, for SC&A evaluation, identified RFP worker neutron doses 

for the 1953-1958 time period in a document provided on the O-drive, NIOSH RFP NP Ratios 
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using NDRP Data for 53-58. An additional document is being prepared (NDRP Paired Neutron 

Gamma Sets).

2.3 REVIEW SCOPE 

 

The Department of Labor (DOL), with assistance from NIOSH, will perform the task of 

identifying members of the SEC class. Since this report is a review of the evaluation report 

prepared by NIOSH, it does not address the protocols that DOL may use to decide which 

claimants are members of the class. However, this review does include analysis of NIOSH’s 

limitation of the proposed class to certain buildings, since that analysis is part of the evaluation 

report. 

This report includes a review of NIOSH’s conclusion that it can reconstruct doses for all 

employees in the 1952–2005 period other than members of the proposed class. The comments in 

this review do not address the issue of minimum dose reconstruction for compensation only 

under 42 CFR Part 82, since the purpose here is to support the Board’s discussion of dose 

reconstruction under 42 CFR Part 83. 

In preparing its review, SC&A was particularly attentive to the EEOICPA, which states that a 

class of employees may be considered part of the SEC if, “HHS [U.S. Department of Health and 

Human Services] determines that (1) it is not feasible to estimate with sufficient accuracy the 

radiation dose that the class received; and (2) there is a reasonable likelihood that such radiation 

dose may have endangered the health of members of the class” (42 CFR Part 82). 

In this regard, SC&A assessed the degree to which the evaluation report provided the technical 

basis for concluding that it is, in fact, feasible to estimate with sufficient accuracy the radiation 

doses to those members of the class for whom the evaluation report effectively recommends 

against granting SEC status. In addition, in preparing this report, SC&A drew upon the 

requirements of 42 CFR Part 83 and the guidance provided by the Board in Report of the 

Working Group on Special Exposure Petition Review (ABRWH 2006a). The following sections 

discuss each of the SEC-related issues that arose during the issues identification and review 

process that began with the issuance of SC&A’s site profile review report, continued through the 

issues identification and review process, and concluded with the issuance of the SEC Petition 

Evaluation Report by NIOSH. The issues are not necessarily addressed in the order in which 

they arose throughout this process. Since the evaluation report contains a new class definition, 

and since some relevant documents were published at about the time that SC&A was completing 

its site profile review, this review of NIOSH’s evaluation also covers these other issues, as 

appropriate.
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3.0 HIGH-FIRED PLUTONIUM OXIDE 

3.1 OVERVIEW OF ISSUES 

The Rocky Flats SEC-00030 petition has raised concerns about worker exposures to a unique 

form of plutonium referred to as high-fired plutonium oxide (PuO2). Formed at temperatures of 

1,000oC or higher, this plutonium compound has been shown to remain in the lung for much 

longer times than predicted by the default Type S International Commission on Radiological 

Protection (ICRP) lung model. 

In dose reconstruction, the proportion of plutonium lung burden in the respiratory tract relative to 

that in systemic tissues profoundly affects the interpretation of bioassay data that may include 

chest counting and urinalysis. For example, a chest count that assumes Type S plutonium would 

significantly underestimate the duration of time that plutonium remained in the lung and, 

therefore, underestimate the lung dose. Even more troublesome is the reconstruction of lung 

doses based on urinalysis. When urinalysis data are used, the first step in dose reconstruction is 

to estimate the inhaled intake, based on a model that mathematically describes the relationship 

between the observed plutonium content in urine samples and the amount of previously inhaled 

plutonium. For example, the erroneous assumption of default Type S plutonium, for the 

interpretation of bioassay results from urine samples that corresponds to a high-fired plutonium 

intake, will significantly underestimate the amount of inhaled plutonium. In addition to the 

underestimation of the intake, if default Type S parameters are used, plutonium in the lung is 

further underestimated by the assumption of faster biological removal processes. 

NIOSH has acknowledged that high-fired plutonium existed at Rocky Flats and that selected 

workers may have been exposed. NIOSH has also acknowledged that PuO2 may exhibit longterm retention in the lung exceeding that predicted by the default Type S model. 

Correspondingly, NIOSH has addressed these issues in ORAUT-OTIB-0049 (ORAUT 2007b). 

As part of SC&A’s review of the Rocky Flats SEC-00030 Petition, SC&A has conducted a 

thorough review of the methodology proposed by NIOSH in terms of its scientific merit and the 

degree to which outstanding uncertainties are bounded by assumptions that give the benefit of 

doubt to the claimant. SC&A provided the Advisory Board with this detailed review, presented 

in Attachment 1, prior to the Board’s June 2006 meeting, where SC&A also briefed the Board on 

its findings. 

3.2 SC&A REVIEW METHODS 

SC&A reviewed the NIOSH site profile for the RFP (Falk 2004) and submitted its draft review 

to the Advisory Board on December 8, 2005. In that review, SC&A stated that workers might 

have been exposed to high-fired plutonium oxides, which are characterized by high plutonium 

lung burdens in relation to the systemic organ burdens, at long times after exposure. As part of 

its “focused” review of NIOSH’s SEC evaluation for RFP, as requested by the Advisory Board, 

SC&A has supported the Board’s working group review of the high-fired plutonium issue. This 

review has included an evaluation of draft ORAUT-OTIB-0049 and its supporting analyses, as 
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well as data related to USTUR autopsy cases. NIOSH used the autopsy cases to validate the 

conservatism of empirical-based assumptions in ORAUT-OTIB-0049. 

The SC&A staff reviewed the methods used by NIOSH to derive the lung dose adjustment 

factors from in-vivo bioassay results and from urine results, as well as the adjustment factors for 

systemic organs, GI tract, and the extra-thoracic regions. The SC&A staff reviewed the autopsy 

results, the lung count data, and the urinary excretion data for a representative number of RFP 

cases. Cases included individuals who had intakes of the high-fired plutonium oxide, Type 

Super S (Type SS) absorption type, and other types of exposures to plutonium oxides not 

necessarily classified as Type SS at the time of the exposures. The review compared post-1965 

measured lung count data with autopsy data and the predicted values using the NIOSH ORAUTOTIB-0049 empirical model. Calculations were performed considering Type S and Type SS 

material using the urine excretion data, as well as the lung count data. SC&A reviewed the 

autopsy data for lung, liver, and skeletal plutonium content available in most cases. For living 

former workers, lung count and urine data were modeled for organ deposition estimates. 

SC&A also compared the NIOSH approach with a model recently proposed in the literature for 

exposures to high-fired plutonium oxides at the Mayak Production Association, a plutonium 

production facility in the former Soviet Union. 

3.3 SC&A CONCLUSIONS 

Overall, SC&A agrees with the NIOSH approach for estimating annual dose from intakes of 

plutonium that are retained in the lung longer than predicted by the normal absorption Type S 

model, based on the applicability of empirically derived adjustment factors for the lung, systemic 

organs, GI tract organs and tissues, and extra-thoracic regions. SC&A agrees it is claimant 

favorable under this approach to apply the adjustment factors if the intake material is unknown 

and plutonium oxide is a possibility. 

NIOSH has identified selected cases of contamination to high-fired plutonium oxides in its 

“design cases.” Among them, the two with the highest retention in the lung were chosen to 

derive the lung adjustment factors. However, as noted earlier, NIOSH did not explain fully the 

selection rationale for the design cases. NIOSH needed to demonstrate that the most 

conservative among the design cases would also be among the most conservative within the 

whole data file of workers exposed to high-fired plutonium oxides. At the request of the 

Advisory Board working group, SC&A reviewed the representativeness of the 10 model cases, 

upon which ORAUT-OTIB-0049 is based, and 19 other cases from the 1965 RFP fire to 

ascertain whether the NIOSH model envelops the cases and is, therefore, sufficiently 

conservative for broad use. SC&A also completed an evaluation of the ORAUT-OTIB-0049 

application to specific potential RFP exposure cases, including unmonitored workers prior to the 

introduction of in-vivo counting. Attachments 2 and 3 provide these analyses. SC&A also 

concludes that doses to systemic organs can be underestimated when calculated from lung 

measurements. 
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Based on the review of ORAUT-OTIB-0049 and relevant cases that are the basis of the NIOSH 

approach, SC&A concludes that the use of the empirical model and its correction factors is 

plausible for estimating annual dose to the lung, systemic organs, GI tract organs and tissues, and 

extra-thoracic regions for intakes of Pu-239 that are retained in the lung longer than predicted by 

the normal absorption Type S model. The SC&A evaluation found the empirical approach and 

its correction factors to be claimant favorable, as they typically overpredicted the organ 

depositions. 

Based on its review of all 25 workers involved in the 1965 fire, SC&A concludes that the model 

cases chosen by NIOSH as a basis for ORAUT-OTIB-0049 are sufficiently conservative for 

broad use (see Attachment 2). SC&A also concludes that when properly applied, ORAUTOTIB-0049, together with ORAUT-OTIB-0038 and an MDA that includes some extreme 

conditions, can be applied to cover specific exposure scenarios (Attachment 3 provides 

examples) in a claimant-favorable manner: 

 

However, the over-prediction for Type SS or “Super S” is not an unreasonable 

approach, considering the uncertainties that exist in the measured values (lung 

counts and urine assay models), and in particular, the autopsy extrapolations that 

were made. On this last point, an RFP site expert notes from first-hand 

knowledge that when the autopsy tissues were analyzed, the tracheal-bronchial 

lymph nodes and the bronchial-pulmonary lymph nodes were separated out, and 

the pathologist usually took a small portion of the lymph nodes and the lung tissue 

at the autopsy. Likewise, the pathologist usually took a portion of the liver, and, 

only representative samples of bone (a rib, a vertebral wedge, a femur ring, the 

sternum tree, a very small skull bone sample, part of the time the patella and a 

collar bone) were collected from which the skeletal deposition was extrapolated. 

This tissue sampling would contribute to the aforementioned uncertainties.

With respect to NIOSH responses to other petitioner issues related to high-fired plutonium 

oxides exposures, SC&A agrees with the positions taken in the evaluation report, as discussed 

below. 

Particle Size 

SC&A agrees with the NIOSH proposal of an adjustment factor for particle sizes in calculations 

of doses to the lung from urine bioassay results, as stated in ORAUT-OTIB-0049: 

PARTICLE SIZE ADJUSTMENTS FOR RFP PLUTONIUM FIRES 

Dose adjustment factors are based on the assumption of a 5-μm activity median 

aerodynamic diameter (AMAD) particle size (ICRP 1994). For the RFP 

plutonium fires, a particle size of 1 μm AMAD is recommended (ORAUT 2005). 

The dose adjustment factors underestimate the annual lung doses by a factor of 

2.6 for 1 μm AMAD aerosols because the deposition in the alveolar interstitial 

(AI) region of the lung is 2.6 times greater for 1 μm aerosols than 5 μm aerosols 

per unit intake. For energy employees involved in a plutonium fire at RFP (or 
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any time the dose reconstructor deems use of a 1-μm AMAD particle size 

appropriate), the dose adjustment factors in Attachment D must be multiplied by 

an additional factor of 2.6. Note that when the assessment is based on chest 

counts, the adjustment for particle size is not necessary because the lung 

deposition is directly measured, i.e., the dose would be adjusted upwards by this 

factor, but in order to get agreement in the Types S and SS predicted chest 

burdens, it would then need to be adjusted down by the same factor. (ORAUT 

2007b) 

Self-Absorption in High-Fired Particles 

SC&A agrees with the NIOSH position that any nontrivial self-shielding of the 60 keV gamma 

radiation (from the Am-241 daughter upon which plutonium lung counting relies) from a 

“ceramicized” high-fired plutonium particulate would not be plausible. This is based on the 

NIOSH calculation of expected reduction in radiation emitted by an assumed ceramically 

encased particle of 0.12 μm diameter, which showed a reduction of approximately 0.03% in the 

emitted gamma signal. 

Finally, the NIOSH approach for Type SS, high-fired plutonium is effective only if implemented 

as proposed for all RFP dose reconstruction cases where the intake material is unknown and 

plutonium oxide is a possibility. 

The SC&A analysis applies only to cases where the exposure was due to inhalation. The 

findings of this report about the proposed NIOSH approach for estimating lung dose and 

nonrespiratory tract doses are restricted to that exposure route. Specifically, the model may not 

be scientifically suitable or claimant favorable if the main intake route was via a wound. 

3.4 SC&A’S REVIEW OF THE ROCKY FLATS LUNG AND URINALYSIS 

MONITORING RESULTS FOR THE DESIGN OF THE HIGH-FIRED 

PLUTONIUM MODEL 

SC&A has reviewed the data from the six RFP workers (design data) involved in the 1965 fire, 

which were used to derive the high-fired plutonium oxides model. 

Lung Data (1965 and 1969 Fire) 

The lung data used for the design of the model (design data) were compared to the HIS-20 

database for the six cases. In the document “Observations of Lung Count Data in HIS-20” (Falk 

2006), NIOSH acknowledged that there was a mistake in the units used in the HIS-20 database. 

Even after correction for the difference in units, most of the values used for the design cases and 

the ones from HIS-20 do not match. 
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NIOSH has responded to SC&A with the correction factors used for reevaluation of the lung 

monitoring results in HIS-20. These correction factors should be discussed with NIOSH but are 

not an SEC issue. 

 

One of the individuals whose data were used to design the high-fired plutonium model was a 

claimant. The original lung data expressed as counts per minutes, μg, or fraction of lung burden 

in the lung were reported as zeros in the HIS-20 database and were converted into pCi of 

plutonium in the design data set. The original lung data, when expressed in nCi, match the HIS20 values, after correcting for the units. 

The lung monitoring data from the firefighter who was exposed in the 1969 fire were retrieved 

from the 1969 logbook (monitoring data from May 11, 1969–August 2, 1969). Data from this 

worker were also used to derive the high-fired plutonium model. Three very high values 

recorded in the logbooks were not used in the design data set. The other values were around 

20% higher than the original ones. 

Urinalysis Data

Original urinalysis data were retrieved from the bioassay logbooks. The 1966 and 1968 

logbooks were not available to SC&A. For urinalysis data of this claimant, SC&A found no 

significant differences between the three data sets (design data, HIS-20, and bioassay logbooks). 

3.5 SC&A’S REVIEW OF THE ROCKY FLATS LUNG AND URINALYSIS 

MONITORING RESULTS FROM FIVE WORKERS INVOLVED IN THE 1965 

FIRE WHOSE DATA WERE NOT USED IN THE DESIGN OF THE HIGHFIRED PLUTONIUM MODEL 

Five workers involved in the 1965 fire were claimants, and their lung and bioassay data were 

compared to the HIS-20 database. 

Lung Data 

In general, the HIS-20 database for lung results is incomplete. NIOSH acknowledged that there 

was a mistake in the units used in the HIS-20 database, as described in Falk 2006. 

After correcting for the units, the existing results in HIS-20 match the original ones with a few 

exceptions. 

This review found that lung data used to calculate dose for one claimant were applied without the 

correction factors that NIOSH had applied to the design data set. SC&A believes that if a 

correction factor must be applied to lung monitoring results in the design data set, it should be 

applied to results for all claimants. 
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Urinalysis Data 

In general, SC&A found the HIS-20 database for urinalysis results to be incomplete, although 

HIS-20 values do match the Health Sciences database. From a comparison of activity 

concentrations between results from the urinalysis record cards and HIS-20, SC&A found that 

many sampling dates do not match. 

 

In further comparisons for validation purposes, SC&A found that the data from the urinalysis 

cards match the data in the bioassay logbooks. 

The review found that some of the claimants had plutonium intakes prior to the 1965 fire. Those 

were the cases with higher lung burdens than the design cases. The appendices provide a 

detailed analysis of these data. 

3.6 SC&A’S REVIEW OF THE ROCKY FLATS URINALYSIS MONITORING 

RESULTS FROM 12 NONCLAIMANT WORKERS INVOLVED IN THE 1965 

FIRE WHOSE DATA WERE NOT USED IN THE DESIGN OF THE HIGHFIRED PLUTONIUM MODEL 

SC&A compared the data from the HIS-20 database to the data in the available urinalysis 

logbooks. Many dates from HIS-20 did not match the ones in the urinalysis logbooks. There are 

a few differences in the results, but in general, the results from HIS-20 match the ones from the 

available logbooks. 

Only one of the workers without prior exposures to plutonium had sufficient urine data to be 

included among the design cases. 

3.7 SC&A’S REVIEW OF THE ROCKY FLATS USTUR DATA FOR A WORKER 

INVOLVED IN THE 1965 FIRE WHOSE DATA WERE NOT INCLUDED IN 

THE HIS-20 DATABASE 

Results for two workers who were involved in the 1965 fire were not included in HIS-20. One 

of them was a USTUR case, and urinalysis and lung monitoring data from this worker were in 

the USTUR file. This worker died in 1970, and these data could not have been included among 

the design cases, as the design model is meant to cover long term retention of the high-fired 

plutonium oxides in the lungs. 

3.8 SC&A REVIEW OF THE ROCKY FLATS PLANT DATA FROM THE 25 

WORKERS INVOLVED IN THE 1965 FIRE 

SC&A has revised the data from the 25 workers involved in the 1965 fire. The raw lung data 

were modified according to the adjustment factors described in ORAUT-TKBS-0011-5, 

Attachment B (Falk 2004). These adjustment factors were not discussed with NIOSH but were 

applied as established in ORAUT-TKBS-0011-5. The initial ppm value of Am-241 was also not 

discussed with NIOSH. These adjustment factors and the initial ppm value of Am-241 are not 
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SEC issues for ORAUT-OTIB-0049 but should be the subject of further discussion. SC&A 

analyzed the data from the 25 workers and concluded that the design cases were correctly 

chosen. Only one other worker would qualify as a design case, but the inclusion of his data 

would not have modified the adjustment parameters chosen in ORAUT-OTIB-0049. 

Attachment 2 shows the details of these comparisons. 
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4.0 INTERPRETATION OF EXTERNAL DOSE DATA 

4.1 INTRODUCTION AND OVERVIEW OF ISSUES 

The Rocky Flats SEC-00030 Petition (USWA 2005) has raised issues concerning workers’ 

external dose exposures. The petition presented items that the petitioners believe would prevent 

adequate external dose reconstruction for RFP workers by NIOSH. These items include 

concerns about inadequate monitoring, lack of monitoring, changes in methodology, and 

inconsistency in procedures over the history of RFP. The petitioners provided further details 

about external dose exposures, handling of dosimeters, and lack of dose records. They included 

letters and testimonies with the petition attesting to certain incidents throughout the history of the 

RFP site that could lead to lack of external dose information necessary for claimant-favorable 

dose reconstructions. Some of the areas identified in the petition were the lack of adequate 

neutron monitoring in the 1950s; problems with neutron track plates (NTP) and NTA film 

reading and records; improper storage of workers’ and control dosimeters; TLD chips on the 

floor in the counting room; placement of dosimeter/exposure geometry; and zero or no data 

available in workers’ dose records. The petitioners presented details of these and other areas that 

they believe demonstrate that it is not feasible to perform dose reconstruction with sufficient 

accuracy under 42 CFR Part 83 for all classes of RFP workers identified in the petition. 

NIOSH has acknowledged that certain areas of external dose records are incomplete and that 

dose reconstructions for some workers will require correction factors to be applied to doses that 

were recorded, and assignment of coworker dose data when dose records are incomplete or 

contain gaps. Additionally, NIOSH has recognized the necessity of assigning missed dose 

because of the lower limits of detection (LODs) for external dosimeters. To correct the recorded 

external doses and to assign external doses to unmonitored workers at RFP during the period 

1952–2005, NIOSH has recommended using the RFP Occupational External Dosimetry 

technical basis document (TBD), ORAUT-RKBS-0011-6 (Langsted 2004); the NDRP Report 

(ORISE 2005); ORAUT-OTIB-0020 (Merwin 2005); ORAUT-OTIB-0027 (Smith 2005a); 

ORAUT-OTIB-0050 (Smith 2005b); and ORAUT-OTIB-0058, Revision 01 (Smith 2007). 

NIOSH has stated that it has access to sufficient information to either (1) estimate the maximum 

external radiation dose for every type of cancer for which radiation doses are reconstructed that 

could have been incurred under plausible circumstances by any member of the class; or 

(2) estimate the external radiation doses to members of the class more precisely than a maximum 

dose estimate (NIOSH 2006a, p. 65). 

SC&A has reviewed the Rocky Flats SEC-00030 Petition (USWA 2005) and NIOSH’s April 7, 

2006, evaluation report (NIOSH 2006a). Additionally, SC&A has evaluated the Introduction 

TBD (Little 2004), the Site Description TBD (Flack and Meyer 2004), the Occupational External 

Dosimetry TBD (Langsted 2004), the NDRP report (ORISE 2005), ORAUT-OTIB-0020 

(Merwin 2005), ORAUT-OTIB-0027 (Smith 2005a), ORAUT-OTIB-0050 (Smith 2005b), and 

ORAUT-OTIB-0058 (Smith 2007). SC&A has used this information to evaluate whether 

NIOSH has sufficient data and adequate methods to perform external dose reconstruction with 

sufficient accuracy under 42 CFR Part 83 by being able to estimate a plausible upper bound for 

all members of the class. This is not necessarily the same as being able to perform dose 
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reconstruction for individual workers. Being able to perform dose reconstructions does not, by 

itself, prove that NIOSH can meet the requirements of 42 CFR Part 83. 

 

4.2 SC&A’S REVIEW METHODS 

SC&A has reviewed the above-listed RFP TBDs and TIBs, some of their recent revisions, the 

NDRP Report, the Rocky Flats SEC-00030 Petition, NIOSH’s evaluation report on the petition, 

and NIOSH’s external dose reconstruction example cases. In addition, SC&A has engaged in 

extensive phone conferences, interviews, and correspondence with the petitioners/workers, 

NIOSH, and the document authors. SC&A has also accessed and analyzed many of the RFP 

documents that are available concerning external radiation exposures, dosimetry, dose records, 

and operational history at RFP from 1952–2005. 

SC&A then evaluated NIOSH’s overall dose reconstruction approach using the information 

SC&A had acquired from these documents. For issues concerning neutron exposures, SC&A 

performed a detailed analysis of two related TIBs, ORAUT-OTIB-0050 and ORAUT-OTIB0058, and provided NIOSH with an evaluation report for these TIBs. SC&A also examined the 

NDRP report in the context of ORAUT-OTIB-0058. For issues concerning composite neutron 

plus photon, photon, and/or beta doses, SC&A analyzed the workers’ detailed dose data that 

were made available to determine the adequacy of the dose records and the applicability of 

coworkers’ dose to unmonitored workers. At times, it was difficult to acquire the details of the 

annual neutron doses separate from the composite doses along with the workers’ identifications 

(IDs) and work locations for the period 1952–1969. This evaluation is based on the data that 

have been made available to date and the TIBs currently available. 

The following sections detail the results of SC&A’s review of the RFP documents, analysis of 

the available external dose data and its sufficiency for dose reconstruction, and the evaluation of 

NIOSH’s dose reconstruction approach. 

4.3 CREDIBILITY AND CONSISTENCY OF RFP DATA 

In the evaluation report on SEC-00030, NIOSH concludes that sufficient data exist to reconstruct 

external doses for all members of the proposed class for 1952 to the present. SC&A agrees that 

many of the RFP workers’ dose records provide the necessary information for adequate dose 

reconstruction; however, several areas of the dose records raise the concern that claimantfavorable data may not always be present. 

4.3.1 Completeness of Records for 1969 and 1970 

During SC&A’s review, a number of former workers from RFP were interviewed. Many of 

them expressed particular concern about the May 11, 1969, fire and its relevance to their dose 

reconstruction. SC&A reviewed DOE records if available for individuals raising this particular 

concern. In some cases, SC&A noted that on the Occupational Dose Report (handwritten 

external data summary), the shallow and deep doses were blank. Computer printouts of deep 

dose results within the health physics file were recorded as zero in the list of 1969 results, in 
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place of the blanks. Hence, some records contain blanks and zeros, while others, for the same 

worker and the same badging period, contain zeros only. SC&A has verified that this situation 

applies to a number of claimants whose employment period included 1969. SC&A also 

observed that doses during 1970 were significantly lower than those for 1968 or 1971. 

In interviews with workers who had gaps in their 1969 records, SC&A asked them if they had 

been assigned a dosimeter in 1969. The individuals indicated that there was no break in their 

monitoring and that they did enter radiological areas during 1969 and 1970. Because SC&A 

encountered this situation in several individual files, it conducted a review of the number of 

zeros in the file “RFP Coworker Data Stat (NDRP included, HIS-20 Data)” available on the 

O-drive (NIOSH 2006l). SC&A found a sudden increase in the percentage of zeros from 1968 to 

1969. The high percentage of zeros continued during 1970 and then dropped significantly in 

1971. 

These facts about the external dose records for 1969 and the first part of 1970 raise some 

questions:

• What was the reason for the blanks in the records? 

• How were blanks recorded in dosimetry logs and the HIS-20 database?

• Was there a common reason for the increase in blanks and zeros in 1969 in the individual 

raw data files? 

• What were the reasons for the increase in the zeros recorded in 1969 (relative to 1968)? 

• What were the reasons for the increase in the zeros recorded in 1970 (relative to 1968)? 

• Did the blank records that were assigned zeros correspond to exposure potential below 

the LOD for the badges of the time? 

• How are the zeros in the dose records from unread and read badges to be distinguished, 

assuming that the zero results for read badges are less than the LOD? 

As a result of the preliminary concerns raised by SC&A, NIOSH evaluated potential hypotheses 

to explain the gaps, including whether they were related to the May 11, 1969, fire and its 

subsequent cleanup. 

Summary of the NIOSH Analysis of the 1969 Data Gap 

In response to SC&A’s concern, NIOSH determined that 136 claimants had gaps in dosimetry 

records for 1969. Further analysis of these individuals indicated that they held a wide variety of 

jobs from administrative to production. In a few cases, the individual arrived at RFP within the 

last month of 1969 and may not have had dosimetry results for that year. NIOSH investigated 

the radiation files of each worker in an attempt to ascertain reasons for the apparent gap. The 
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investigation centered on 136 claimant files that had been identified as missing data for 1969. Of 

the 136, 35 had no external dosimetry data at all for 1969 for reasons that could not readily be 

explained. NIOSH clarified the problem in the following statement (NIOSH 2006m): 

Only 26% of the records tentatively identified as “missing” were completely 

missing. Four of those in the table were not RFP employees during 1969 and 

another 17 were employed for less than a calendar quarter. For nearly 60% of 

the records there was some data reported, albeit sometimes only a single zero 

entry of a badge coding of “01” which indicated that the badge was not returned. 

Therefore, the putative gap is considerably smaller than it seemed originally. 

NIOSH tested several hypotheses to explain the gap, including data having been lost as a result 

of the 1969 fire, a computer reporting problem, and the possibility that some badges were simply 

not read. Since data exist for first responders and employees who participated in cleanup 

operations related to the 1969 fire, NIOSH concluded that the gap was not connected with the 

May 11, 1969, fire. NIOSH stated (NIOSH 2006m): 

The external dose monitoring patterns observed in 1969 are consistent with a 

combination of the policy to not read badges for staff in non-Pu areas on 

quarterly badge exchange cycles, and a computer problem that arose during this 

period resulting in dose being reflected only in cumulative dose totals. The 

programming error that reportedly resulted in a loss of monthly and quarterly 

detail data for 400 workers certainly would have created an apparent gap in the 

records for those staff, but would not have impacted their cumulative doses 

because the gap was discovered and addressed. 

 

NIOSH concludes (1) the 1969 data gap is much smaller than originally 

estimated, (2) the patterns observed in the 1969 dosimetry data are consistent 

with the administrative decision to not read film badges from employees stationed 

in non-Pu areas with low exposure potential, and (3) a computer programming 

error may have contributed to the lack of detail in the dosimetry data, but this was 

discovered and corrected in the cumulative dose totals. Therefore, NIOSH 

concludes that dose reconstructions can be performed with sufficient accuracy for 

claimants employed at Rocky Flats in 1969.

The working group asked SC&A to review the NIOSH analysis. 

Evidence of Systemic Data Gaps 

SC&A identified a sudden jump in zero entries from 1968 to 1969. The high proportion of zeros 

continued into 1970 and then declined in 1971. These data were compiled from the RFP dose 

data posted on the O-drive (ABdoc review->RF->coworker data->RFP coworker data Stat 

(NDRP included, HIS20 data) posted 4/17/06). Table 4-1, which summarizes the number of zero 

entries each year in the HIS-20 database, shows that the percent of zero entries increases 

dramatically for these 2 years. Both 1969 and 1970 had over 36% zero entries for penetrating 
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(neutron + photon) external doses, while the previous 5 years (1964–68) showed an average of 

9.7% zero entries and the subsequent 5 years (1971–1975) had an average of 10.5%. This is 

especially relevant because many workers were involved in a major fire that occurred during the 

second quarter of 1969. 

Table 4-1. Percent of Zero Doses Recorded for 1952–2005 

Pene. Dose 

w/zeros 

Pene. Dose w/o 

zeros 

Year # of entries # of entries # of Zeros % of Zeros 

1952 42 42 0 0.0 

1953 319 290 29 9.1 

1954 353 273 80 22.7 

1955 529 426 103 19.5 

1956 781 662 119 15.2 

1957 918 804 114 12.4 

1958 1062 927 135 12.7 

1959 1063 1011 52 4.9 

1960 1284 1065 219 17.1 

1961 1638 1461 177 10.8 

1962 2003 1779 224 11.2 

1963 2176 2047 129 5.9 

1964 2834 2610 224 7.9 

1965 2826 2639 187 6.6 

1966 2888 2658 230 8.0 

1967 2902 2530 372 12.8 

1968 3101 2690 411 13.3 

1969 3471 2197 1274 36.7 

1970 3308 2096 1212 36.6 

1971 3398 2995 403 11.9 

1972 3282 2621 661 20.1 

1973 3020 2465 555 18.4 

1974 2687 2658 29 1.1 

1975 2489 2461 28 1.1 

1976 2424 2271 153 6.3 

1977 3740 2347 1393 37.2 

1978 4176 1781 2395 57.4 

1979 3893 2441 1452 37.3 

1980 3752 1760 1992 53.1 

1981 4060 1496 2564 63.2 

1982 4851 2490 2361 48.7 

1983 5360 3631 1729 32.3 

1984 5673 3607 2066 36.4 

1985 6140 3993 2147 35.0 

1986 4942 4603 339 6.9 

1987 2583 2354 229 8.9 
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Table 4-1. Percent of Zero Doses Recorded for 1952–2005 

Pene. Dose 

w/zeros 

Pene. Dose w/o 

zeros 

Year # of entries # of entries # of Zeros % of Zeros 

1988 2778 2503 275 9.9 

1989 5296 2891 2405 45.4 

1990 3369 2602 767 22.8 

1991 5641 4951 690 12.2 

1992 5831 5429 402 6.9 

1993 5313 4534 779 14.7 

1994 4839 3198 1641 33.9 

1995 4130 2502 1628 39.4 

1996 3454 2761 693 20.1 

1997 3718 2452 1266 34.1 

1998 3470 2036 1434 41.3 

1999 3655 2138 1517 41.5 

2000 3576 1256 2320 64.9 

2001 3443 1518 1925 55.9 

2002 3502 1147 2355 67.2 

2003 3373 947 2426 71.9 

2004 2758 559 2199 79.7 

2005 955 562 393 41.2 

SC&A investigated whether this sudden increase and then decrease in the number of zeros was 

indicative of data entry or credibility problems and what the implications might be for dose 

reconstruction. 

SC&A also noted that similar sudden jumps in zeros appeared from 1976 to 1977. The high 

proportion of zeros persists until 1985 and then drops in 1986. SC&A has not investigated these 

additional years with high proportions of zeros in detail; however, several changes in the 

dosimetry program occurred around this time. In 1976, the dosimetry group implemented the 

Health Sciences Database (Langsted 2004). At about that time, a decision was made to change 

the background subtraction method for TLD dose determination (Lagerquist 1975a): 

Beginning January 1, 1976 we will be subtracting background from all external 

radiation measurements of our employees. 

This background will be the average of the environmental measurements that we 

have made on plant site and in nearby communities.

Lagerquist (1976) indicated that an average background of 0.34 mrem/day was subtracted from 

the badge. There was also a proposal to record zero for doses less than 10 mrem as stated in a 

memorandum by Lagerquist “We are considering converting all employee readings of less than 

10 mrem to zero also, but we want to look at the 1976 data first. (Lagerquist 1976).
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Further, americium operations changed in 1976, and americium recovery was stopped in the late 

1970s (Flack and Meyer 2004, pp. 11–12). The end of these operations would be expected to 

significantly reduce external dose in some plutonium areas. SC&A did not discover comparably 

large external dose gaps for entire years in this period in its random sampling (see Section 8), 

indicating that the zeros in these later periods were readings less than the detection limit rather 

than gaps. 

Claimants with Data Gaps 

NIOSH identified 136 claimant files as “missing data for 1969,” with 26% of these files 

determined to have no external dosimetry for all of 1969 and others having data for portions of 

the year. NIOSH listed only one “Fire Protection Engineer” and one firefighter. Table 4-3 

contains a subset of the 136 individuals, all with blanks for four quarters of data on their 1969 

Health Physics External Radiation Exposure Report (HPERER) in the health physics file. These 

19 individuals worked all four quarters during 1969, and most continued employment into 1970. 

Each also had at least one badge reading in the 1969 Dosimetry Processing logs, where there was 

no indication of a late or unreturned badge. 

Note that Individual 19, listed in Table 4-3, is a firefighter. He indicated in his computerassisted telephone interview (CATI) that he was involved in “suppressing the fire” and in 

subsequent fire watches. In fact, he received an in vivo count shortly after the fire for a 

“potential inhalation from the 776 fire.” There is no explanation for the data gap for him in 

1969. In its late February 2007 report on the 1969 data gaps, NIOSH presented evidence 

regarding the external exposure conditions affecting the employees who dealt with the aftermath 

of the fire: 

Another piece of information that applies to this claimant is found in the July 24, 

1969 memo from Mann to Piltingsrud, shown above. Mann indicates that in the 

two month period including and immediately following the May 11, 1969 fire the 

maximum dose received by any of the 208 cleanup personnel was less than 200 

mrem. A draft memo originally dated May 16, 1969 states “Fifty special 

thermoluminescent dosimeter badges have been used so far by Dow employees 

and members of the investigating team. To date, no significant external exposures 

have been measured on any one entering Building 776” (1). These contemporary 

results belie the presumption that significant doses were missed for workers 

involved in the fire’s aftermath. Taken together, the urinalysis results, lung 

counts and ambient gamma exposure information for the fireman (ID #19) 

indicate that he did not accumulate a large dose during his fire suppression or 

fire watch activities. (NIOSH 2007b, pp. 9–10) 

SC&A agrees with NIOSH that external dose gaps for those involved in the aftermath of the fire 

are not an SEC issue. 
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The case of an individual not listed in Table 4-3 should also be considered.2

 In fact, he 

submitted an affidavit within the SEC petition in which he raised concerns that his film badge 

readings did not match his job duties. He worked as a laboratory technician supporting 

nondestructive analysis. According to the petition affidavit and the CATI, this individual 

performed duties in buildings all over the site, including plutonium processing buildings. The 

1969 dose on his HPERER was blank for all four quarters. The first three quarters on the 1970 

HPERER were recorded as zero with a significant drop in annual exposure for that year 

compared to doses in 1965-1968. No data from1969 were available for this individual on the 

Dosimetry by Individual Report or in HIS-20—that is, the year 1969 was missing altogether 

from the Dosimetry by Individual Report and the worker was not in the HIS-20 external dose 

database. The recorded deep doses for 1965, 1966, 1967, and 1968 were 1,512, 1,804, 4,130, 

and 645 mrad respectively, all above the 10% limit. The personnel file indicates that this worker 

was assigned to Building 444 in 1965 and 1966. For portions of 1967 and 1968, the individual 

spent time in the plutonium areas. The individual stated in the CATI that he was involved in the 

1969 fire cleanup. Within the health physics file are reports indicating that he received an 

abrasion in 1969 and a puncture wound in 1969 in Building 777. This would indicate that during 

at least some portion of 1969, he was working in Building 777. It is noteworthy that for at least 

three quarters in 1969, the individual was formally assigned to Building 444, which was a 

nonplutonium area even though he was performing work in a plutonium area. There were no 

densitometer readings in the dosimetry processing logs, and zeros were entered for three quarters 

in the dose readings with arrows, indicating that his badges were not read. In the fourth quarter, 

there is a blank in the log, with a notation that the badge was not returned, although he was still 

listed as being assigned to Building 444. He was on a quarterly badge cycle. This case raises 

questions regarding the policy of not reading badges for nonplutonium areas that was instituted 

in 1969. It shows also that individuals entered areas other than those to which they were 

formally assigned and illustrates as well the complexities introduced into dosimetry issues by the 

fire and the earlier decision on selective nonreading of quarterly badges. 

NIOSH responded to these observations in its February 2007 report as follows: 

NIOSH investigated this claimant’s file and determined that, indeed, doses from 

1965–1968 were higher than for 1969 and beyond, however SC&A only considers 

the doses prior to 1969 and makes no mention of the lower doses in the following 

years. For most of his career, he was a laboratory technician. In 1967 and 1968, 

he conducted non-destructive testing in buildings 777 and 991. In December 

1968 he was transferred to building 444 and later in September 1969 to building 

881 where he was stationed until August 1971. Hence, it is likely that in 1969 he 

was subject to the badge no-read policy outlined earlier. As demonstrated by his 

much lower doses in the years following 1969 during which he was stationed 

outside the Pu areas, his doses were far lower than in the years prior to 1969 

when he was stationed in Pu areas. This example validates the premise that 

2

 He was not included in the table because his data are completely missing from the HIS-20 database, 

making a comparison with the other databases impossible. His name is slightly misspelled in the 1969 Dosimetry 

Processing Logs. SC&A verified the data by reference to his badge number. 
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workers stationed outside the Pu areas on quarterly badge cycles were at low 

exposure potential. 

In May, 1969, he received a puncture and an abrasion to the right hand while 

doing decontamination in building 776, but a wound count showed no levels 

above background. Urinalysis results for 1970 and 1971 showed no 

contamination. (NIOSH 2007b, pp. 10-11)

Finally, the Mann memo of July 24, 1969 indicates that no fire cleanup personnel 

had received greater than 200 mrem. Therefore, this claimant likely did not 

receive a large dose during the 1969–1970 period. In spite of this, such an 

unmonitored worker would be assigned a penetrating dose of 2,702 mrem 

according to OTIB-58, which is a factor if 2.6 higher than any worker involved in 

the fire cleanup. NIOSH notes however, that this was unnecessary in this case, as 

the individual’s dose reconstruction has been completed, with a probability of 

causation >50%. Therefore, there was nothing here which prevented NIOSH 

from completing dose reconstruction with sufficient accuracy. 

The point of SC&A’s observations in this case is that workers stationed in nonplutonium areas 

appear to have been involved in the cleanup after the fire. The NIOSH response confirms this. 

SC&A agrees with NIOSH that the assignment of dose to those involved in the cleanup is not an 

SEC issue. The matter is raised here in the context of the gaps for 1969 and whether there are 

appropriate ways to address these gaps. 

On May 11, 1969, a large self-ignited fire occurred in Building 776, and contamination spread to 

Building 777. A total of 33 firefighters and security guards fought the fire at various times. 

Personnel were contaminated at levels from a few hundred to greater than 100,000 

disintegrations per minute (dpm) alpha/60 cm2

. Dow medical personnel, radiation monitors, 

body counter technicians, and six U.S. Atomic Energy Commission (AEC) personnel assisted in 

decontamination, monitoring, and contamination control. In the first 24 hours, 41 employees 

were decontaminated and checked with the body counter. Initial counts indicated that 15 of the 

41 employees had positive plutonium results. The only significant inhalation of plutonium 

attributed to the fire involved a firefighter who was given an in vivo count after being 

decontaminated (AEC 1969). 

Several radiation monitors relayed to SC&A that they discarded contaminated badges, or 

discarded badges on significantly contaminated clothing (see Attachment 4). Logbook entries 

reviewed for other time periods support the practice of destroying contaminated badges in the 

field (see Attachment 5). This would be a reasonable solution if badges could not be 

decontaminated because the facility would not have wanted to contaminate the Dosimetry 

Processing Laboratory. The destruction of contaminated badges may also have contributed to 

the gaps in 1969. The Dosimetry Processing logsheets for 776 are divided into 776A and 776B. 

For May 1969, 776A and 776B had a total of 90 and 192 individuals listed, respectively. The 

logsheets for 776A identified 16 badges as “not returned.” Those for 776B identified 59 badges 

as “not returned.” This high level of “not returned” badges may be indicative of badge 
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destruction in the field when badges were contaminated. This would not be restricted to specific 

areas on the plant site and would have implications for plutonium as well as nonplutonium area 

workers.3

Again, this issue is raised in the context of addressing gaps in the 1969 time period in question. 

The SC&A investigation of the completeness of worker dosimetry data (Section 8.0) noted that 

in several of the cases examined, NIOSH has incorrectly used methods based on the LOD to 

assess doses at times when there were gaps in the data records. The SC&A discussion of 

personnel involved in the fire who have gaps in their data records should be placed in this 

context. A coworker dose assignment is appropriate, rather than a missed dose LOD-based 

assignment. SC&A concurs with NIOSH that such an assignment is possible based on available 

data. 

Computer Error 

Individuals responsible for data processing were actively involved in the development of 

computer programs for TLD dose calculating programs, data management, and sample 

scheduling during the early part of 1969. In some cases, they experienced difficulties. The 

Status Report—Dosimetry—February, 1969 (Mann 1969a) indicates a data processing error for 

the year-end (presumably 1968) external exposure data: 

The year end external exposure data program appears to be correct now. 

Corrections necessary to the periodic film badge runs have not been made yet. 

We are not getting satisfactory service from this group (Data Processing). 

The Status Report—Dosimetry—April, 1969 (Mann 1969b) noted a computer error: 

The entire film badge program is being rewritten to take care of recent 

programmer errors. We are furnishing accumulated dose to date data on 400 

"lost" employees to up-date their master tape. 

Specifically, it appears from the early 1969 dosimetry progress reports that the data processing 

group was having difficulties with the year-end external data for 1968. Furthermore, letters in 

health physics files document a computer error occurring in 1968 (RI 1976). Possibly, the error 

NIOSH was associating with 1969 is actually related to 1968 data. Adjustments to dose 

(cumulative or otherwise) were often documented on a letter and placed in the individual health 

physics file. There is no indication of an adjustment in accumulated dose for 1969; however, 

letters were present in the health physics files for adjustments made as a result of a computer 

error in 1968 (RI 1976). 

3

 Note that SC&A’s screening analysis of minimal data completeness in Section 8 does not include partial 

year missing data, such as that created by discarding one or two badges in a year. 
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Nonplutonium Area Badges Not Processed 

SC&A concurs with NIOSH that RFP decided not to read nonplutonium area badges in early 

1969, prior to the fire. In a letter to Mann, Vogel (1969) recommended that nonplutonium area 

film badges not be processed because most of the individuals received less than 10% of the inplant working level: 

It is recommended that the film badge continue to be issued and worn as it has 

been but that the film not be processed except for a few specific groups or for 

particular circumstances.... The circumstances that might require processing of 

film for some individuals or groups would include accidents, special operations 

work involving special material, or to reaffirm the validity of this approach.

(Vogel 1969) 

Table 4-2 lists the “nonplutonium” area buildings and briefly describes the activities that 

occurred in these buildings. 

Table 4-2. Description of Nonplutonium Buildings as Determined by 

RFP Radiological Control 

Badge Storage Area 

Building No. Description of Activities 

111 Administrative Building 

121 Plant Security and Armory 

122 Emergency Medical Services Facility 

123 Analytical Health Physics Laboratory 

125 Standards Laboratory

331 Vehicle Maintenance and Fire Station 

334 Central Shop and Maintenance 

440 Transportation Modification Center 

441 Production Support 

442 Filter Test Laboratory and Warehouse 

444 Depleted Uranium Processing 

551 General Warehouse 

705 Coatings Laboratory

750 Production Engineering Support 

881 Manufacturing and General Support 

883 Uranium Rolling and Forming Operations 

865 Metal Research and Development Laboratory 

The specific groups in the nonplutonium areas exempted from this practice included Health 

Physics Electronics, Health Physics Operations, Nuclear Safety, Uranium Chemistry in Mfg., 

Production Control in Mfg., and Quality or Nondestructive Testing. While it was not considered 

necessary to wear the film badge to measure this very low-level chronic exposure, Management 
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felt it desirable to wear the film badge to measure accidental exposure. Vogel (1969) indicated 

that implementation of this policy would result in a reduction in film processing workload by at 

least 1,000 packets per quarter. 

The film was to be retained for a several weeks after the regular film badge change before it was 

discarded (Vogel 1969). The Status Report—Dosimetry—March, 1969 (Mann 1969c) indicates 

that the practice of not reading quarterly issued badges was implemented: 

Quarterly badges for the non-Pu areas will no longer be read routinely, 

except for a few higher risk groups. The film will be changed as usual, but will 

not be read unless circumstances warrant. 

A memorandum from Mann to the dosimetry technicians (Mann 1969d) informs them that the 

policy would be effective with the first quarter change of 1969 and that badges would be 

discarded not long after return. The memorandum states, “Film from the badges of all other 

groups [those not processed] is to be saved for three weeks after the exchange, then discarded.”

SC&A notes that this policy of not reading some workers’ badges was instituted before the May 

11, 1969, fire. SC&A partially concurs with the NIOSH contention that many of the gaps in data 

are not related to the fire. However, as noted above in the case of the firefighter, it appears that 

external dose data related to the fire also have gaps. 

Unread badges also appear to be indicated when zero is recorded for the dose result, but no 

density readings are listed for the particular badge as they are for those that are clearly read. 

After reviewing the Dosimetry Processing Logs, SC&A noted that quarterly badge results are 

primarily recorded as zero for a number of RFP buildings (e.g., 441, 444, 881, and 883). The 

lack of density readings persisted through 1969 and 1970. Furthermore, badges from plutonium 

area workers did have density readings recorded. One difference between 1969 and 1970 was 

that handwritten Occupational Dose Reports indicated zero in 1970 rather than blank, which was 

the case in 1969. It is possible that the zeros in the dose columns for deep and shallow dose in 

the Dosimetry Processing Logs were entered without a corresponding density entry as a matter of 

convenience. However, it is much more likely that they were zero entries when badges were not 

being read, since a policy to this effect was instituted in 1969. Other evidence, discussed below, 

clearly leads to this conclusion. NIOSH’s reading of these logs is the same as SC&A’s—that 

these zero entries represent unread badges: 

Monthly "Status Reports" prepared by John Mann, the manager of the Dosimetry 

Program addresses the issue of data sheets with zeros written at the top and with 

arrows down the entire page. The status report dated April 8, 1969, Item A.3 

states: "Quarterly badges for the non-Pu areas will no longer be read routinely, 

except for a few higher risk groups. The film will be changed as usual, but will 

not be read unless circumstances warrant.” (NIOSH 2006m) 
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Table 4-3 lists 19 claimants with 1969 gaps from among the 136 individuals initially identified 

as having data gaps in the Occupational Dose Report. These individuals worked all four quarters 

during 1969 and most continued employment into 1970. SC&A examined four different data 

records for these 19 individuals for 1969: 

• The Occupational Dose Report, which is the handwritten summary dosimetry report in 

the Health Physics file. 

• Dosimetry History by Individual, which is a computer printout generated prior to the 

HIS-20 database creation. 

• The HPERER, which is a quarterly summary report. 

• The HIS-20 computerized database, which NIOSH is using for its coworker model.4 The 

individuals also had dose values for 1969 in the RRFP Coworker Stats (NDRP Included, 

HIS-20) file located on the O-drive. In each case, all the blank values in the HPERER 

were recorded as zeros in the HIS-20 database. 

Examples of the Occupational Dose Report, Dosimetry History by Individual, and HPERER are 

available in the External Dosimetry TBD (Langsted 2004, pp. 52–55, 61). The individuals also 

had dose values for 1969 in the RRFP Coworker Stats (NDRP Included, HIS-20) file located on 

the O-drive. SC&A reviewed each of the four external dosimetry sources to determine the dose 

values entered for 1969. 

In all 19 cases, the HPERER data show blanks for the entire year (indicated as “Null” in 

Table 4-3). In the handwritten Occupational Dose Report in their health physics file, 16 cases 

show blanks, while 3 individuals did not have such a report in their health physics file. A typed 

version of an Occupational Dose Report under a different name is not referred to here since it 

was available for only a few individuals. Table 4-3 indicates “null” only when a blank was 

documented for each quarter of 1969. Hence, both the Occupational Dose Report and the 

HPERER data show by their blank entries that the badges of these workers were not read. 

In contrast, the Dosimetry History by Individual computer printouts show the following (see 

Table 4-3): 

• Zeros for 10 individuals having 1969 data for the deep dose instead of blanks and a blank 

for the shallow dose 

• No Dosimetry History by Individual in the health physics file for nine individuals 

(indicated by N/A) 

4

 At this stage, SC&A has not established whether the external HIS-20 has been used in individual dose 

reconstruction. 
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Finally, the HIS-20 database shows zeros in all 19 cases for both shallow and deep dose. This 

would demonstrate that, in both the processing logbooks and the computerized databases, unread 

film was entered as a zero. The entry of zeros for unread badges leads to the conclusion that the 

sudden increase in zeros in 1969 in the HIS-20 database (Table 4-1 above) is very likely due 

largely to a zero entry in the database in place of the blanks in the Occupational Dose Reports 

and the HPERER data. This conclusion is buttressed by the fact that the decision not to read a 

certain category of badges resulted in a large decline in the number of badges read (1,000 

packets per quarter—see above). The other bases for this conclusion include the following: 

• The number of zeros from 1968 to 1969 increased from 13.3% to 36.7%. 

• Quarterly cycle badges were not read starting in 1969 (Mann 1969c). 

• The blanks in some databases show up as zeros in others, notably the HIS-20 database 

and the Dosimetry History by Individual. 

• Workers with blanks (subsequently zeros in the HIS-20 database) were assigned to areas 

considered nonplutonium work and fit the profile of those referred to in the memorandum 

for nonreading of issued badges. These blanks, and subsequent zeros, are unrelated to the 

May 1969 fire. 

• The same workers had densitometer readings in earlier periods, but none in 1969. 

The practice of recording zeros for dose and providing no densitometer readings in the 

Dosimetry Processing Logs continues into 1970. The existence of non-zero doses for the same 

workers in the HPERER records in 1970 indicates that the practice may have changed before the 

end of the year. This change in recording practice is also reflected in the reduction in the 

percentage of zeros from 1970 to 1971. SC&A has not found any document that establishes a 

definitive date for the ending of the practice of not reading issued badges. NIOSH has also not 

been able to locate any such document but has concluded that the practice of nonreading of 

badges stopped by the end of 1970 and “earlier for some buildings” (NIOSH 2007b, p. 4). 

It is possible that the nonreading of badges of at least some workers started earlier than 1969 and 

continued later than 1970, as evidenced by the case of a secretary who had blanks in her 

dosimetry record from 1963 to 1973 (November 6, 2006, working group meeting transcript, 

pp. 76-78). This raises the possibility that the 1969 policy change was a formalization or 

continuation of an earlier practice that may have affected a smaller number of workers. 

However, it is also possible that the employee in question was not issued a badge and that others 

in a similar situation were also not issued badges even after the dosimeter and ID were combined 

into one badge in 1964 (see Chapter 8). 

In summary, based on information in dosimetry correspondence, Rocky Flats implemented a 

practice of not reading the assigned quarterly dosimetry badges of nonplutonium workers in the 

first quarter of 1969. As NIOSH has stated, the Dosimetry Program addresses unprocessed 

dosimeters by recording zeros on the logsheet and/or arrowing down the page, with zeros 
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recorded at the top. Figure 4-1 is an example of a logsheet that shows arrowing down the page. 

The evaluation of 19 claimants with data gaps in the year 1969 determined that the HIS-20 and 

Dosimetry History by Individual data files contain zeros in cases where badges were not read, 

contributing to the significant increase in the number of zeros from 1968 to 1969. This brings 

into question the integrity of those data records and partially substantiates worker claims that 

RFP recorded zeros when badges were not read (and not just when they were not handed in). 

The individuals whose badges were not read were assigned to “nonplutonium” areas as defined 

by Rocky Flats Radiological Control staff. As shown in Table 4-3, many of these individuals 

were located in uranium areas where uranium was handled or processed (e.g., 444, 881, and 

883). Others were employees who were housed in nonplutonium areas or administrative 

buildings but visited radiological areas (including plutonium areas) as a part of their job 

responsibilities. 

To further evaluate the exposure of nonplutonium area workers, SC&A compared doses from the 

fourth quarter 1968 Dosimetry Processing sheet and the first quarter 1969 Dosimetry Processing 

sheet for 18 individuals. The individuals were assigned to Buildings 111, 331, 441, 444, or 883 

during this period. The policy of not reading nonplutonium area badges was implemented in the 

first quarter of 1969. SC&A compared the logsheets for the fourth quarter 1968 and first quarter 

1969. Table 4-3 provides the results of this comparison. Table 4-4 contains the recorded doses 

for the fourth quarter 1968 and first quarter 1969 from the HPERER in the health physics file. 

Figures 4-2 and 4-3 are examples of the fourth quarter 1968 logsheets and the first quarter 1969 

logsheet. With a few exceptions, the same individuals are included on both sheets. All 

individuals were on a quarterly exchange cycle, and there was no indication of a late or 

unreturned badge. The results from the 1969 first quarter logsheet were all zeros or zero with an 

arrow down the page. As the table and the figures show, doses were not zero in the fourth 

quarter of 1968 prior to the implementation of the no-read policy. This review also indicated 

that although badges were not read in the first quarter of 1969, the individual may have readings 

for later quarters. In these cases, the annual dose for 1969 would reflect the dose from the 

quarters when badges were read. This implies that gaps in 1969 can occur for only a portion of 

1969. Hence, the problem of zeros in the 1969 data record when badges were not read is larger 

than that indicated when only blanks for the entire year are considered. 

External dose exposure potential, notably shallow external dose in some uranium areas, could be 

very high. This is noted in the Rocky Flats site history (Putzier 1982): 

 

In earlier years in handling large quantities of depleted uranium, and to some 

extent this is true in more recent years, we did have a significant radiation control 

problem in Building 444. This was not experienced so much in the machining 

areas but in the part of the foundry operations we call burnout and breakout. 

Castings were removed by breaking them out of the molds. This operation and 

the recovery of the material from the casting and handling the molds themselves 

resulted in very high beta radiation levels. There was an extremely high level of 

beta radiation associated with this because the first two daughters of 238U are 

beta emitters and during the molten state of the uranium there is a tendency for 
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these two daughters to flow to the top and also to show up at the interface of the 

uranium and the mold itself thereby enhancing the amount of beta radiation 

coming off from the chunk of the material. We used to use as a rule of thumb that 

clean uranium metal in equilibrium with at least its first two daughters would give 

off on the order of 200 mrad per hour beta radiation at the surface of a piece of 

the metal. This went up by at least an order of magnitude and probably more 

than that. We can say that we saw readings as high as 2000 to 3000 mrad/hr on 

castings of depleted uranium that were in the foundry area. Then, too, the dusts 

which were generated in the burnout and breakout areas settled on various pieces 

of equipment and from that there were additional beta radiation fields generated. 

This also resulted in excessive dust in the atmosphere. The housekeeping of these 

areas was indeed a very important control problem, and as I recall, in those days 

was handled very well. (Putzier 1982, pp. 74–75 of the pdf file) 

This description of radiological conditions in at least some uranium areas from the 1950s into the 

early 1980s (though apparently with less intense problems in the later years) shows that external 

shallow dose rates in some uranium areas were very high—much higher than the theoretical 

maximum of about 240 mrad/hour contact dose with U-238 metal in equilibrium with Th-234 

and Pa-234m. The high dose rates and non-zero doses mean that the zeros that were entered in 

place of blanks for unread badges cannot be generally interpreted as LOD or LOD/2. NIOSH 

has made this interpretation in at least some dose reconstructions as revealed by the data 

completeness evaluation performed by SC&A. These issues, including the locations and periods 

where there are the largest gaps in dosimetry data, are discussed in more detail in Section 8.0 on 

completeness of data. 

 

The nonreading of badges and input of zeros in the data records, including the HIS-20 database, 

in place of blanks raise four distinct issues of data integrity: 

• Not reading badges that were issued is not consonant with sound practice, especially 

since at least some of the workers concerned were known or should have been known to 

have prior exposures above the LOD of the badge. Throwing away the badge after a few 

weeks converted a problem of unsound practice to a problem of data integrity because it 

obviated any possibility of verifying the low exposure assumed in initiating the practice. 

• While the practice of not reading badges may have been intended to minimize the work 

of reading badges of workers judged to have low exposure potential, the facts relating to 

at least some nonplutonium work indicate that this was an erroneous belief, notably for 

shallow dose. The practice of nonreading of badges that were issued appears to support a 

claim in the SEC petition that workers with significant exposure potential had zeros 

entered in their badge records. This is not a statement about the ability to fill the gaps 

using a suitable method. Rather, it is a statement about the integrity of the data record in 

its own right, independent of exposure potential. 

• Entry of zeros in some data records when the badges were not read, and were in fact 

discarded, raises questions about the integrity of the data recording practices. SC&A has 
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found no evidence of intent to fabricate data. However, SC&A also notes that a record 

containing zeros for badges that were not read is fundamentally flawed inasmuch as the 

records do not correspond to the reality of the working conditions of at least some of the 

affected workers. That part of the record for 1969 and 1970 does not meet the test of 

scientific integrity of data as it is commonly understood. 

• Some workers whose badges were not read appear to have worked in plutonium areas 

even though their formal assignments shown on the Dosimetry Processing Logs are to 

nonplutonium areas. Nonreading of such badges, especially during the post-fire period, 

necessitates the use of appropriate coworker data, which appear to be available. 

Conclusions 

Based on their analyses of the problem, SC&A and NIOSH concur that there are gaps in the 

1969 external dosimetry data for some workers. A significant part of the problem arises from the 

policy of not reading quarterly badges (with some possible exceptions) instituted in 1969. The 

practice continued into 1970 as discussed above. 

SC&A has concluded that the integrity of at least a portion of the 1969 and 1970 dose record has 

been significantly compromised by the practices discussed above. During the March 7, 2007, 

Advisory Board working group meeting, the director of OCAS, Larry Elliot, characterized the 

zeros entered for the badges that were not read as “bad data” and suggested that affected workers 

be considered “unmonitored” with no recorded dose for the time periods involved (Rocky Flats 

working group meeting, March 7, 2007. SC&A concurs with this assessment. 

There are indications that the policy of not reading issued badges stopped by the end of 1970. 

However, NIOSH cited the nonissuance of badges to some prime contractor employees as an 

explanation for the case of the secretary who had blanks in the dosimetry record from 1963 to 

1973 (inclusive). An investigation is needed to determine whether badges were not issued to 

workers who were assessed to have low exposure potential or whether they were issued and not 

read as a matter of informal policy (which was formalized in the first quarter of 1969). In either 

case, the dose reconstruction for workers with gaps outside of 1969 and 1970 should take into 

account that the gaps cannot be treated as being equivalent to missed dose (i.e., a badge reading 

below the LOD). 

As discussed in the completeness evaluation (Section 8.0), it appears possible to construct 

coworker models to bound adequately the dose for workers affected by gaps in their dosimetry 

records. Either the existing coworker model must be demonstrated to be bounding for the 

specific times and working conditions involved or new coworker models need to be developed. 

Since the nonreading of badges in 1969 and 1970 occurred primarily for a worker population 

similar to the one not badged earlier, the development of appropriate methods to fill the gaps 

should be possible. 
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SC&A recommendation regarding zero entries to replace gaps: SC&A recommends that all 

zeros entered when badges were not read be dropped from the data record and the gaps be 

identified as such. This would ensure that fundamentally flawed data are not being used in dose 

reconstruction. The dose reconstruction should use coworker data that bound the dose that 

would have been received in the working conditions in the specific jobs being done by the 

employees affected by the gaps in 1969 and 1970. Gaps from other periods, due to nonissuance 

or nonreading of badges, should be treated in the same way. NIOSH must demonstrate that the 

selected approach(es) bound the dose for the affected members of the class. 

4.3.2 Problems with Gaps, No Reading, No Current Data Available, and Zero Entries 

In the evaluation report concerning SEC-00030, NIOSH explains the data entries of (1) No 

Reading, (2) No Current Data Available, or (3) a Zero Entry. The response explains that a 

missed dose (based on LOD) will be assigned for this period and the total dose recorded at the 

end of the next period, effectively increasing the total recorded dose. 

Data entries of “No Reading,” “No Current Data Available,” or “Zero” have been an area of 

controversy during the evaluation of this SEC, even if the dose is actually recorded later in the 

records. If the dosimeter is actually worn for two periods and then read and recorded, the 

suggested NIOSH procedure represents a claimant-favorable approach. However, there is no 

way to be certain that the badge was not lost, damaged, or unreturned if the dose of record shows 

No Reading, No Current Data Available, or Zero, and the worker’s file contains no other 

information concerning the data entry. Assigning a missed dose based on LOD is not acceptable 

for lost, damaged, or unreturned badges, as it in no way reflects the actual dose received. 

Assignment of dose based on adjacent readings is possible, if there are no incidents/accidents 

(such as fires) during the unmonitored periods to create abnormal exposures. 

SC&A’s review of 52 claimant files for completeness of data throws additional light on this 

question. The details are discussed in Chapter 8. For purposes of the external dose coworker 

model, we note that the SC&A review found significant gaps in internal and external dose 

records. It is likely that the internal dose gaps can be filled since the data for workers with high 

cumulative dose did not reveal year-long monitoring gaps. However, external dose data for nonplutonium workers in the 1950s have significant gaps, even among some workers with high 

cumulative exposure. 

SC&A Evaluation: SC&A concludes that No Reading, No Current Data Available, or zero 

entries from badges that were worn for two exchange periods do not present an SEC issue for the 

most part. It remains for NOSH to demonstrate either (1) that the external dose coworker model 

bounds the dose the nonplutonium workers in the 1950s, or (2) that there are sufficient data for 

those workers in the 1950s to develop supplementary models that can bound their individual 

doses.
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Table 4-3. A Comparison of Data Sources for Claimants with 1969 Gaps 

ID Job Title Bldg Occupational Dose Report 1969 Dosimetry History by Individual 1969 HPERER 1968 HPERER 1969 HPERER 1970 HIS-20 1969 

1 Inspector Null N/A Skin Only Null 14 0 2 Maintenance Electrician No 51-79 datasheet N/A 362 Null 0 0 3 Mechanical Maintenance No 51-79 datasheet 0 14 Null 0 0 4 Accountant Null 0 Null Null 0 0 5 Cost Accountant Null 0 Null 0 0 6 Mechanical Development Null 0 92 Null 23 0 7 Truck & Labor Null 0 35 Null 0 0 8 Civil Engineer Null 0 10 Null 0 0 9 Tool Engineering Null 0 Skin Only Null 0 0 10 QA Inspector Null N/A 7 Null 0 0 11 Sr. Material Specialist Null 0 24 Null 26 0 12 QC Inspector Null N/A 171 Null 0 0 13 Production Eng Null N/A 38 Null 150 0 14 Facility Engineer No 51-79 datasheet N/A 137 Null 19 0 15 Sr. Fire Protection Engineer Null 0 14 Null 0 0 16 R & D Engineer Null N/A 187 Null 144 0 17 Sr. Research Mgr. Null N/A Skin Only Null 188 0 18 Inspector Null N/A 8 Null 55 0 19 Fireman Null 0 23 Null 77 0 

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

within the requirements of 42 CFR 82. 
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Table 4-4. Nonplutonium Area Worker Dose for Fourth Quarter 1968 and First Quarte

ID Job Title Work Location Dosimetry Log Gamma Dose Q4 1968 Dosimetry Log Beta Dose Q4 68 HPERER Deep Dose Q4 1968 HPERER Shallow Dose Q4 1968 HPERER Deep Dose 1969 

101 Electrician 33 95 33 128 Null 102 X-Process Opr 142 1240 142 1382 Null 103 Journeyman Machinist 33 1880 33 1913 Null 104 Journeyman Machinist 96 300 96 551 Null 105 Tool Grinder 16 95 16 111 Null 106 Journeyman Machinist 16 95 16 111 Null 107 Journeyman Machinist 16 125 16 141 Null 108 Journeyman Machinist 42 80 42 122 Null 109 Inspector 42 80 42 122 Null 110 Journeyman Machinist 33 50 33 83 Null 111 Mtce Machinist 42 80 48 62 Null 112 Journeyman Machinist 16 95 16 111 Null 113 Sr. Industry Photographer 74 77 75 77 Null 114 Advanced Facility Engineer 137 139 137 139 Null 115 Vehicle Driver 164 173 167 173 Null 116 Designer I 89 98 92 98 Null 117 Equipment Opr 222 632 222 632 Null 118 Equipment Opr 152 832 152 832 Null 

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within the requirements of 42 CFR 82. 
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Figure 4-1. Example Logbook Sheet with Zeros Followed by Arrowing Down 

Fourth Quarter 1968 Dosimetry Logsheet for Individuals on a Quarterly Cycle 

from Building 111 
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Figure 4-2. Fourth Quarter 1968 Dosimetry Logsheet for Individuals on a Quarterly 

Cycle from Building 111 
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Figure 4-3. First Quarter 1969 Dosimetry Logsheet for Individuals on a Quarterly Cycle 

from Building 111 
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4.3.3 Average Worker, Not Maximum Exposed, Monitored Prior to 1964 

Another area of data credibility and consistency concern is the fact that page 65 of the evaluation 

report (NIOSH 2006a) states that in the early 1950s, only groups expected to receive doses 

greater than 10% of the Radiation Protection Guidelines (called the “threshold dose”) received 

dosimeters. However, this type of badging policy would indicate that the most exposed workers 

were badged and the number of zero entries would be minimal. If this were true, then in 1964 

when the decision was made to badge more workers, presumably with lower exposures, the 

number of zero entries should have increased noticeably. However, Table 4-1 shows that during 

the 5-year period of 1959–1963 (before 1964), the average number of zero entries was 10.0% vs. 

9.7% for the 5-year period for 1964–1968. This would indicate that workers who were not 

monitored before 1964 were similar to those who were monitored, at least so far as potential for 

exposure over the LOD was concerned. NIOSH did provide a recent report concerning RFP 

external badging practices. While this report does a good job of summarizing the badging 

policies, it does not add significant information for the period of most concern (1952–1963). 

(See Attachment 7 for NIOSH’s report and SC&A’s evaluation.) 

SC&A Evaluation: This is a site profile issue, not an SEC issue, apart from the caveat relating 

to nonplutonium workers in the 1950s noted in Section 4.3.2. However, the use of dose data that 

is considered the result of monitoring the maximum exposed, when it actually reflects average 

exposures, could bias the coworker data to low values and result in underestimation of the doses 

of unmonitored workers. This applies to both photon and neutron exposures. 

SC&A Conclusions Regarding RFP Data Credibility and Consistency: SC&A has 

concluded that for the most part NIOSH has sufficient data and methods to perform external 

photon dose reconstruction with sufficient accuracy under 42 CFR Part 83. However, it remains 

for NIOSH to demonstrate that it can adequately bound external shallow and deep dose for all 

nonplutonium workers in the 1950s. Furthermore, several areas could lead to an SEC issue 

concerning neutron doses, as detailed in the following sections. 

4.4 DATA AVAILABILITY AND SUFFICIENCY FOR COWORKER MODEL 

External dose data are available for many workers at RFP for 1952–2006. However, some 

situations where dose data are not readily available may cause an underestimate of worker dose. 

This section discusses several areas of concern. 

4.4.1 Analysis of Data to Determine Applicability to Early Unmonitored Workers 

The Advisory Board’s February 2006 working group meeting in Boston initially addressed the 

issue of completeness of external exposure data. NIOSH responded to SC&A’s concern in the 

site profile review (SC&A 2005d, Section 5.11.2, pp. 102–104) in a brief summary provided at 

that meeting. At the meeting, NIOSH stated, “For those individuals who are not badged, the 

dose reconstruction process uses documented unmonitored dose techniques to estimate dose.” 

The two main areas of SEC concern are the early neutron dose entries used for coworker data in 

ORAUT-OTIB-0058 and the increase in the percentage of zero entries during 1969–1970 (the 
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latter is addressed in Section 4.3.1). ORAUT-OTIB-0058 outlines the recommended procedures 

for using coworker dose data to assign external doses to unmonitored workers at RFP. NIOSH 

refers to this document and related documents in its evaluation of SEC-00030. Tables 7-1 and 

7-2 of ORAUT-OTIB-0058 (Smith 2007) provide averaged coworker data for each year. Note 

that ORAUT-TKBS-0011-6, Revision 01 (Langsted 2007), was issued February 8, 2007, and 

ORAUT-OTIB-0058, Revision 01 (Smith 2007), was issued January 8, 2007 (Revision 02 may 

be issued in the near future). This complicates SC&A’s evaluation of the previously issued 

(April 2006) NIOSH evaluation report of the SEC. Therefore, this report attempts to blend the 

information contained in these time-sensitive documents into an evaluation that is as current as 

possible, but could be subject to change in the future, because of the fluidity of the situation. 

During its investigation, SC&A found that dose monitoring at RFP falls into four major time 

frames; therefore, it is most effective to address the issues in each of these time periods. The 

following summarizes SC&A’s current understanding of the proposed neutron and related 

photon dose reconstruction procedures used by NIOSH for RFP workers for the time periods 

1952–1958, 1959–1969, 1970–1976, and 1977–2005. This is followed by SC&A’s evaluation of 

the issues for each time period, especially as they relate to the SEC. 

(Note: According to ORAUT-OTIB-0058, when using data from the tables for any of these time 

periods, the 95th percentile values are to be applied to workers who were likely to have been 

exposed to radiation, and the 50th percentile values are to be applied to workers who may have 

been intermittently exposed to radiation. If a worker was unlikely to have been exposed to 

radiation (e.g., work locations were away from the laboratory buildings that contained 

radioactive materials), then only the ambient dose will be assigned.) 

1977–2005 

The following is SC&A’s present understanding of NIOSH’s recommended procedure for 

determining neutron and related photon doses for this period when neutron and photon doses for 

monitored workers were measured using TLDs and were recorded as separate doses: 

• Neutron and photon doses will be assigned as per DOE dose records measured by TLD 

monitoring. 

• If neutron monitoring results are not available, an n/p value of 0.42 will be applied to the 

total of the measured photon plus the assigned missed-photon dose to determine the 

neutron dose. The n/p value of 0.42 was obtained from the TLD badge results of 1977–

2000, as detailed in ORAUT-OTIB-0050, page 8, and will be applied to all work 

locations. 

• If neither neutron or photon monitoring results are available, the worker will be assigned 

a coworker photon dose each applicable year, as provided in ORAUT-OTIB-0058, 

Table 7-2, and a corresponding neutron dose as provided in that table, which is 0.42 times 

(photon dose–the missed dose). Table 7-1 of ORAUT-OTIB-0058 provides the total of 

the photon plus the neutron dose obtained from Table 7-2. 
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SC&A’s Evaluation: This approach has no known SEC issues. The applicability of using a 

single n/p value of 0.42 for all years during 1977-2005 and for all work locations could be a site 

profile issue, but not an SEC issue. 

1970–1976 

The following is SC&A’s present understanding of NIOSH’s recommended procedure for 

determining neutron and related photon doses for this period when the original dose data were 

stored as a composite neutron plus photon dose value: 

• Composite (neutron + photon) doses measured by TLD/film monitoring will be obtained 

from DOE dose records, if available. Neutron and gamma doses will be separated out 

from the DOE recorded composite dose by using the separate photon and neutron data 

contained in the Health Physics TLD Badge Reports for that worker for each monitoring 

period. The worker’s external dose will be assigned according to the separate neutron 

and photon doses. 

• If the worker’s composite dose is available, but the separate photon and neutron data are 

not available, then the n/p values in Table 6-2 of ORAUT-OTIB-0058 will be used to 

separate out the neutron and photon doses from the DOE-recorded composite dose. The 

geometric mean (GM) n/p values in Table 6-2 were obtained from the neutron and photon 

dose data contained in the Health Physics TLD Badge Reports; they range from 0.67 to 

1.61, with an overall average of approximately 1.0 for the 5 years of real data (1971, 

1972, 1974, 1975, and 1976). For 1970, 1971 was used, and 1972 was used for 1973, 

because reliable data were not available for those 2 years. The worker’s external dose 

will be assigned according to the separated neutron and photon doses. 

• If the composite dose is not available, the worker will be assigned a coworker photon 

dose for each appropriate year, as provided in Table 7-2 of ORAUT-OTIB-0058 and a 

corresponding neutron dose as provided in that table, which is based on the n/p value for 

that year from Table 6-2 of ORAUT-OTIB-0058. Table 7-1 of ORAUT-OTIB-0058 

provides the total of the photon plus the neutron dose obtained from Table 7-2. The 

worker’s external dose will be assigned according to the separate neutron and photon 

doses. 

SC&A’s Evaluation: This approach has no known SEC issues. The applicability of using a 

single n/p value each year for all work locations during 1970–1976 could be a site profile issue, 

but not an SEC issue. 

1959–1969 

The following is SC&A’s present understanding of NIOSH’s recommended procedure for 

determining neutron and related photon doses for this period when some, but not all, workers 

were monitored with photon and NTA film badges. The NTA films were reread in the NDRP 
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project for this period. The n/p values for different buildings (mainly plutonium-related) for the 

years 1959–1969 were calculated and are presented in Table 11.1 of the NDRP Report using the 

results of matching pairs of neutron and photon film results. These n/p values range from 0.3 to 

10, with an average value of approximately 2 (n/p=10 is noted as an upper bound and not an 

actual measured value). 

• For workers who were monitored for both neutrons and photons, doses will be assigned 

as per DOE dose records, which were measured by photon and NTA film badges, and 

modified as appropriate using NDRP results. 

• If neither original neutron dose readings nor NDRP reread results are available, the n/p 

values in Table 11.1 of the NDRP will be applied to the total measured photon dose to 

determine the neutron dose according to the appropriate year and building. When there 

were gaps in the photon monitoring, NDRP notional neutron doses were not assigned 

during that period. If the worker was not in one of the listed buildings (Buildings 71, 76, 

78, or 91), or the work location cannot be verified, the worker will be assigned a neutron 

dose based on the n/p value for buildings in the “All Others” category. The average n/p 

values for the “All Others” building category are approximately 75% of the values for the 

listed buildings. 

• If neither neutron or photon monitoring results are available, the worker will be assigned 

a coworker photon dose each year, as provided in Table 7-2 of OAUT-OTIB-0058 and a 

corresponding neutron dose, as provided in that table, which is based on the measured 

coworkers’ photon doses (but excludes any assigned missed doses) and n/p values for 

“All Other” buildings from Table 11.1 of the NDRP Report (ORISE 2005). Table 7-1 of 

ORAUT-OTIB-0058 provides the total of the photon plus the neutron dose obtained from 

Table 7-2. 

It is SC&A’s present understanding from information obtained from NIOSH that for the period 

1959-1969, the NDRP reread-and-dose-assignment project involved the reevaluation of all 

available NTP/NTA badges for plutonium workers and all other workers including those at 

criticality facilities and calibration facilities and any in uranium or other areas. 

SC&A’s Evaluation: Although this approach has no known SEC issues, there are several areas 

of caution: 

• Using the “All Others” building category of n/p values may result in assigned neutron 

doses (from either the known photon dose or from Table 7-2 of ORAUT-OTIB-0058) 

that are less than those that would be obtained from using the n/p values from buildings 

with numbers listed in Table 11.1 of the NDRP. 

• The issue related to the increase in the number of zero entries during 1969–1970 and the 

data gaps during that period is a separate concern, which is addressed in Section 4.3.1.
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1952–1958 

The following is SC&A’s present understanding of NIOSH’s recommended procedure for 

determining neutron and related photon doses for this period when a few of the workers were 

monitored with both photon and NTP/NTA films badges. The NTP/NTA films were reread in 

the NDRP project for this period. There were insufficient paired neutron and photon results to 

create reliable n/p values for each year of this time period. Therefore, the NDRP recommends 

applying the n/p values derived for 1959 in Table 11.1 of the NDRP to the time period 1952–

1958. These n/p values range from 0.6 to 3.6 (depending on building location), with an average 

value around 1.6. 

• For workers who were monitored for both neutrons and photons, doses will be assigned 

as per DOE dose records measured by photon and NTP/NTA film badges and modified 

as appropriate using NDRP results. 

• If neutron monitoring results are not available, the n/p value for 1959 in Table 11.1 of the 

NDRP will be applied to the total measured photon dose each year to determine the 

neutron dose according to the appropriate building. When there were gaps in the photon 

monitoring, NDRP notional neutron doses were not assigned during that period. If the 

worker was not in Buildings 71, 76, 78, or 91, or the work location cannot be verified, the 

worker will be assigned a neutron dose based on the n/p value for the “All Others” 

building category. The n/p value of 1.2 for the “All Others” building category is 

approximately 75% of the values of the numbered buildings listed. 

• If neither neutron or photon monitoring results are available, the worker will be assigned 

doses as follows (per ORAUT-OTIB-0058, Rev. 01, dated January 8, 2007): 

– Plutonium worker—The worker will be assigned a coworker photon dose each 

appropriate year, as provided in Table 7-2 of ORAUT-OTIB-0058, and a 

corresponding neutron dose as provided in that table, which is based on the measured 

coworkers’ photon doses (but excludes any assigned missed doses) and on the n/p 

value for “All Others” buildings of 1.2 for 1959. Table 7-1 of ORAUT-OTIB-0058 

provides the total of the photon plus the neutron dose obtained from Table 7-2. This 

is the same procedure as used for the 1959–1969 time period. 

– Nonplutonium worker—The worker will be assigned a coworker photon dose for 

each appropriate year, as provided in Table 7-3 of ORAUT-OTIB-0058, which 

excludes NDRP data, i.e., for uranium and other workers. (This procedure may 

change with Revision 02 of ORAUT-OTIB-0058 (see details below).) Neutron dose 

will not normally be applied to nonplutonium workers. If the unmonitored worker 

could have been exposed to neutrons, Table 7-2 for plutonium workers will be used. 

SC&A’s Evaluation: During the evaluation of this SEC report, SC&A requested, and very 

recently received, some separated external neutron and photon annual dose data listed by 

individual RFP workers. SC&A has based its evaluation on this available dose data, n/p values, 
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and NIOSH’s recommended dose reconstruction procedures. The following is SC&A’s present 

understanding of the information provided by NIOSH for the period 1952–1958: 

• The NDRP reread-and-dose-assignment project involved the reevaluation of all available 

NTP/NTA badges for plutonium workers and all other workers, including those at 

criticality facilities and calibration facilities and any in uranium or other areas. 

• Only 20 NTPs from Los Alamos National Laboratory (LANL) were available for each 

badge exchange for 1952-1956 and a limited number of NTA films were available for 

each badge exchange during 1957-1958 at the RFP. 1959 was the first year of significant 

badging for neutrons. 

• SC&A’s comparison of coworker doses derived from 1959 data with measured doses 

revealed that the measured doses were consistently greater than the median of the 

coworker dose. This indicated that the distribution of the coworker model and the 

monitored population is different. NIOSH agreed, stating the monitored population was 

that at highest risk of exposure and that these workers were in Building 91. 

• The SC&A evaluation found that the highest exposures were among the badged workers 

in some years during the 1952–1958 period. However, in others, such as 1955 and 1956, 

the highest doses assigned by NDRP were greater than the highest measured doses. 

• Because of the very limited quantity of neutron badges available, most of the NDRP 

neutron doses assigned for 1952–1958 were derived by using n/p values for 1959 from 

Table 11.1 through the use of notional doses using the n/p method, as opposed to actual 

badge readings. 

• No documentation has been found that could be used to quantitatively compare the 

neutron doses received during 1952-1958 to the recommended neutron dose assignment 

derived from 1959 data. Therefore, the assigned NDRP doses for the 1952–1958 period 

are of questionable validity, as is the coworker model. 

During SC&A’s phone conference with NIOSH on February 14, 2007, NIOSH indicated that 

because of the uncertainties associated with the derivation of the data in Table 7-3 in 

ORAUT-OTIB-0058 for nonplutonium workers, this table may be deleted, and all dose 

reconstructions for unmonitored workers (regardless of plutonium, uranium, or other work 

locations) will use Tables 7-1 and 7-2. Therefore, Table 7-3 and the related Table 7-6 for 

construction trade workers (CTWs) can be removed, and Revision 2 of ORAUT-OTIB-0058 will 

be issued in the near future. This change will simplify the dose reconstruction process while 

remaining claimant favorable without excessive dose assignment. However, one area of concern 

is that the nonpenetrating doses listed in Table 7-1, and perhaps the related Table 7-4 for CTWs, 

could underestimate nonpenetrating dose for uranium workers. Section 8 of this report provides 

additional details concerning this subject. 
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4.4.2 Use of Neutron-to-Photon Ratio Values 

NIOSH has recommended using n/p values to assign neutron doses from records that contain 

composite photon and neutron doses (1970–1976) and to assign neutron doses to unmonitored 

workers (1952–2005). The preceding section that describes NIOSH’s recommended dose 

reconstruction processes for the time periods 1952–1958, 1959–1969, 1970–1976, and 1977–

2005 provides some details of this process. 

SC&A’s Evaluation: To provide an objective view of the entire external dose data and 

coworker model using n/p values, the following tables list a summary of the average n/p values 

as a function of time periods. The values in Table 4-5 indicate a general trend of increasing n/p 

as neutron-emitting sources came on site, followed by decreasing n/p values as time progresses, 

which would be expected as knowledge of neutron radiation advanced (i.e., 1959 ~ 1.5, 1959–

1969 ~ 2, 1970–1976 ~ 1.2, 1977–2000 ~ 0.4). However, the 1952–1958 n/p value of 1.2

(ORISE 2005, Table 11.1, column for “All Others” for 1959), which is used in separating photon 

and neutron doses in Table 7-2 of ORAUT-OTIB-0058, is noticeably less than the average n/p 

values (2.0 and 4.9) in Table 4-6, which are calculated from NIOSH’s sampling of dose data in 

RFP NP Ratios using NPRD Data for 53–58 and contained in the summary sheet of that file. 

Table 4-5. Average n/p Value vs. Time Period, 1952–2005 as per ORAUT-OTIB-0050, 

ORAUT-OTIB-0058, and NDRP 

 

1952–1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977–2005 

Average of 

Pu-buildings 1.6 1.6 2.7 2.6 1.5 1.5 1.7 1.3 0.6 0.9 1.2 2.8 1.6 1.6 1.3 1.3 0.7 0.7 1.0 0.4

“All others” 1.2 1.2 1.8 1.8 2.3 2.3 3.0 0.9 0.5 0.6 1.2 1.5 1.6 1.6 1.3 1.3 0.7 0.7 1.0 0.4

Source 

NDRP NDRP NDRP NDRP NDRP NDRP NDRP NDRP NDRP NDRP NDRP NDRP HP HP HP HP HP HP HP 1977–2000 TLD 

Notes: 1959 n/p values used for 1952–1958, NDRP. 

1962, 1963, and 1964 n/p average values exclude upper-bound value of 10 for Building 91. 

Table 4-6. Average Actual Workers’ n/p Values from NIOSH’s Summary Sheet from 

RFP Neutron-to-Photon Ratios Using NDRP Data for 1953–1958 File 

1952 1953 1954 1955 1956 1957 1958 Math 

average 

Wt. 

average 

Building #71 - - - - - 0.4 2.7 1.5 2.0 

Building #91 3.8 5.3 - 4.8 11.9 2.3 5.9 5.7 4.9 
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The n/p values used to calculate the NDRP “notional doses” for the workers during gaps in their 

neutron monitoring data in 1952–1969 dose records were based on the location of the worker 

during each year and came from Table 11.1 of the NDRP Report (ORISE 2005). This would 

result in a range of n/p values from 0.3 to 10 (10 being an upper bound, not a measured value), 

with an average value of around 2. 

The information available illustrates that the n/p values vary greatly between buildings and from 

year to year for the period 1952-1969 as illustrated in the above tables and in Table 11.1 of the 

NDRP report. No technical basis has been found to verify if these fluctuations are real (i.e., 

resulting from physical changes) and are therefore valid, or if some of them are artifacts 

introduced as the result of other variables that do not concern neutron dose (e.g., changes in 

badging policies, changes in Am-241 content, etc.). Furthermore, Figure 1.1 (ORISE 2005, 

p. 111) shows that individual n/p ratios from paired data could range from ~0.1 to ~40 in a single 

year. 

Some 1952–1958 neutron dose data, with individual dose identifiers, which very recently 

became available, allow several preliminary benchmark comparisons to be made. These 

comparisons consisted of comparing the measured n/p values to those in Table 11.1 of the NDRP 

Report and measured neutron doses to those contained in Table 7-2 of ORAUT-OTIB-0058 

(which were derived by using an n/p value of 1.2 from Table 11.1 of the NDRP Report). Not 

many measured values were available, but there were enough to allow some comparisons. This 

very limited analysis indicates that the 50th percentile should not be used for any significant 

neutron exposure potentials. In its initial investigation, SC&A found that the proposed coworker 

neutron dose was less than the measured neutron dose 25 time out of 25 times at the 50th

percentile level and 6 out of 25 times at the 95th percentile level. The results of these 

comparisons indicates that the neutron dose distribution function for the early monitored

workers (which had a high potential for neutron exposure) is not the same as the neutron dose 

distribution function derived from coworker’s data used to construct the tables in OTIB-0058. 

The early monitored workers were selected to wear the limited number of badges because of 

their high potential for neutron exposures. Therefore, a direct comparison cannot be made 

between the early monitored group and the average radiation worker in 1959. Page 24 of the 

NDRP states, “The N:G building ratios were determined starting in 1959. For the preceding 

years (1952–1958), the values for 1959 were used without modification, since no other 

information was available to justify modifying the values.” According to NIOSH (NIOSH 

2006n), no documentation and/or data has been located that will allow for the direct comparison 

of the neutron doses received during 1952–1958 to the doses that were assigned by the NDRP 

project or will be assigned using the coworker data in ORAUT-OTIB-0058. In other words, 

there is no way to validate the coworker model for the 1952–1958 period. Roger Falk, NIOSH’s 

site expert for Rocky Flats, stated that the NDRP had tried to validate the model for the 1952–

1958 period, but could not find any data to do so. 

SC&A performed a check to see if the most exposed badged workers in the 1952–1958 period 

had consistently higher neutron doses than the neutron doses assigned to those with exposure 

potential by the NDRP project; however, the results were mixed. In some cases, the measured 

doses were the highest, while in others, the assigned doses were the highest.
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Because of the lack of data or documentation being available to compare the 1952–1958 neutron 

doses to the 1959 dose data, SC&A is currently investigating the data and methods used in the 

NDRP Report to assign neutron doses during the period 1952–1958. A supplemental report will 

be issued separately from this report. 

From this analysis, SC&A concludes that the methods and dose data available to NIOSH may 

allow for neutron dose reconstruction with sufficient accuracy for RFP workers for 1959–2005 

using n/p methods. However, for the period 1952–1958, SC&A has concluded that the coworker 

model has not been demonstrated to be bounding. Further, the unmonitored workers with 

neutron exposure potential who were assigned doses as part of the NDRP may have been at 

higher risk in some cases and some years than the monitored workers. The data do not 

consistently validate NIOSH’s claim that the workers with the highest exposure potential were 

monitored. NIOSH’s approach to neutron dose assignment for the 1952–1958 period, including 

its coworker model, has not been demonstrated to represent a bounding dose under 42 CFR 83. 

This issue remains open as an SEC issue for the 1952–1958 period. 

4.4.3 Evaluation of HIS-20 Database for Use in Coworker Model 

The numerical dose data in the HIS-20 database has been used to populate the dose tables in the 

coworker models, such as ORAUT-OTIB-0058. The external dose data contained in the HIS-20 

database has been an area of concern and discussion. SC&A has investigated this database and 

found that it does not contain all the workers’ data for all monitoring periods. However, 

according to NISOH, this database will not be used for individual dose reconstruction but will be 

used in the coworker model. SC&A investigation of the HIS-20 database has revealed the 

following: 

• A sample comparison of RFP logbook entries vs. HIS-20 data entries found that some 

data in the logbooks had not been entered into the HIS-20 database. 

• A sample comparison of RFP Progress Report entries vs. HIS-20 data entries found that 

some data found in the Progress Reports were not entered into the HIS-20 database. 

• The data contained in the HIS-20 database are usually the same, or greater in value, than 

that found in older databases. 

• SC&A has reviewed NIOSH’s evaluation of the data contained in the HIS-20 database 

compared to the original records, such as ORAU-OTIB-0058, page 6. The review found 

that while there are some gaps in the database, the data in the HIS-20 database are 

generally neutral, or claimant favorable, for use in a coworker model. 

• The HIS-20 database contains only composite (neutron + photon) data. 

SC&A Evaluation: SC&A has found that although the HIS-20 database is not complete for 

every monitoring cycle, it does contain sufficient data to allow for its use in conjunction with the 
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coworker model, i.e., ORAUT-OTIB-0058, to assign sufficiently accurate photon doses for 

under-monitored or unmonitored workers at RFP for 1952–2005. However, the use of the 

HIS-20 database for neutron dose assignment, through the coworker model, could lead to 

insufficient accuracy in neutron dose reconstruction as detailed in the n/p section of this report. 

4.4.4 NDRP Applicability Concerns 

The NDRP Report provides some of the QA/QC measures used during the reread process, and 

NIOSH has provided some analysis of the QA/QC procedures used during the NDRP process 

(Attachment 8). 

SC&A Evaluation: SC&A reviewed the NDRP Report for content and its intended use in the 

site profile review and exploration of SEC issues, but it has not formally evaluated the report as a 

stand-alone document. SC&A’s main concern at this time is not necessarily the QC used during 

the reread process, but the fact that some of the workers’ dose data available for the NDRP 

process have large gaps and large periods of employment without neutron dose data. 

Additionally, a recent SC&A review (Attachment 6) of dose reconstruction cases at RFP 

revealed that a significant number of cases had relatively large gaps in their dose records (>5 

years of data gaps). These findings raise the concern that data with large gaps in monitoring 

periods may not be valid for use in deriving n/p values, coworker models, and gap-bridging 

methods. Therefore, these data cannot be used as normal data but must be carefully analyzed for 

zero/blank entries. 

4.5 NEUTRON DOSE DATA ISSUES 

In the past, SC&A has expressed concern about using the NTA film calibration for the NTP 

dosimeters and using only one calibration for NTA film in obtaining the NDRP results. NIOSH 

and SC&A have discussed these issues. SC&A has assumed that all usable NTP and NTA films 

were included in the NDRP reread program, not just those for plutonium workers. The following 

is a summary of SC&A’s findings on these issues.

4.5.1 Use of NTA Calibration for NTP Reread 

SC&A has reviewed the NTP and NTA film reading process at LANL, which read the neutron 

dosimeters for RFP during 1952–1956. According to the NDRP Report (ORISE 2005, p. 15), 

LANL used a calibration factor of 5.55–6.68 mrem-mm

2

/track for 3.35 MeV average energy 

neutrons and 8.33–10.4 mrem-mm2

/track for 5.0 MeV average energy neutrons for the NTPs. 

The NDRP reread process determined a calibration factor of 22.39–36.94 mrem-mm2/ track, with 

an average of 30.86 mrem-mm2/track for both bare (average energy of 1.4 MeV) and 7 cm of 

poly moderator (average energy of 0.15 MeV) from a PuF4 source (ORISE 2005, p. 14), with an 

average blank reading of 2.01 mrem-mm2/track for NTA film. A more recent 1990 LANL 

article, LA-11740-MS (Mallett et al. 1990), recommended using 5.6–10 mrem-mm2

/track. 
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SC&A Evaluation: In view of the information available, it appears that the use of the NTA 

calibration of an average of 30.86 mrem-mm2

/track for the reread of the NTP would be 

reasonable, as recommended on page 16 of the NDRP Report. 

 

4.5.2 Use of One Calibration for NTA Film Reread 

Pages 14 and 15 of the NDRP Report present results indicating that NTA film has the same dose 

equivalent response (average of 30.86 mrem-mm

2

/track) for bare PuF4 (average energy of 1.4 

MeV) as for a 7-cm poly moderated PuF4 (average energy of 0.15 MeV), and conclude that the 

PuF4 source is an appropriate source to represent (alpha,n) neutron sources and also fission 

spectra neutrons at RFP (ORISE 2005, p. 15). While SC&A cannot dispute these findings, 

neither can it find any published data or textbook articles to support them. From the data 

presented in the NDRP Report, an average of 30.86 mrem-mm2/track was obtained from the 

reread of the NTA calibration film exposed to neutron spectra of bare and moderated PuF4

neutrons. However, it is not evident from the TBDs and TIBs that the neutron spectra at RFP are 

necessarily covered by these two neutron energy spectra where the NTA film neutron energy 

threshold is concerned. For example, Figure 3-1 on page 10 of ORAUT-OTIB-0050 (Smith 

2005b) shows that NTA film has essentially zero response to neutrons below 500 keV. 

Therefore, in any situation at RFP where the exposure consisted of neutrons with all energies 

below the 500 keV threshold, the dose would not be registered by the worker’s badge. This 

would not be a common situation but illustrates the fact that the calibration recommended in the 

NDRP could underestimate neutron doses in some situations. 

SC&A Evaluation: SC&A agrees that in certain exposure conditions, the calibration factors 

recommended by NIOSH provide for reasonable dose reconstruction. However, NIOSH does 

not present sufficient evidence that the recommended calibration factors bound the possible 

neutron energy spectra at all RFP facilities during the period that NTP and NTA films were in 

use. This would not be an SEC issue, but a site profile issue. 

4.5.3 NDRP Data in HIS-20 Database 

NIOSH’s evaluation report (NIOSH 2006a, p. 36) states that because there was no way to 

discern the neutron dose, the neutron value in HIS-20 was set to “null” and the deep dose (lump 

sum or annual composite doses) was applied to the gamma component. (It is assumed from the 

previous text that this statement applies to the period of 1952–1976.) Then, the evaluation report 

states the following (NIOSH 2006a, p. 37): 

Since the NDRP program did not always identify the original gamma dose, it was 

determined that only the difference in the original neutron dose and the 

recalculated neutron dose would be incorporated into HIS20.... There were a 

total of 23,386 NDRP neutron dose records for 5244 individuals used to modify 

the HIS20 database. 

The statement on page 36 indicates that the original HIS-20 database does not contain separate 

neutron dose information, but the document then states that the neutron values in HIS-20 would 
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be set to “null” and only the difference in the original neutron dose and the recalculated NDRP 

results would be used to modify the HIS-20 database. It is not clear where the original individual 

neutron doses are stored, and how they can be set to “null,” if only lump sum and annual doses 

are available for that period in the HIS-20 database. Additionally, the document does not state 

why only 23,386 records were used to modify the HIS-20 database when 87,943 NTA 

films/NTPs were matched to workers (ORISE 2005, p. 14). 

SC&A Evaluation: SC&A has recently received clarification of this issue from NIOSH. It is 

SC&A’s current understanding that the HIS-20 database now contains the additional neutron 

doses assigned (the delta value plus any notional doses) added to the original composite dose 

data. Additionally, the 23,386 records referred to in NIOSH’s evaluation report are annual

neutron doses; each contains the information from about 4 reread badges, for a total of 87,943 

reread NTPs and NTA films. Given this clarification, SC&A now agrees with NIOSH that this is 

not an SEC issue. 

4.6 USE AND EFFECTS OF LEAD APRONS 

NIOSH explains the procedure of adjusting for the effects of wearing a lead apron on page 75 

and addresses a particular case on page 72 of the evaluation report (NIOSH 2006a). NIOSH’s 

conclusion is that a lead apron will reduce the dose of record by 0%–15% and that this will be 

compensated for during dose reconstruction. 

SC&A agrees with NIOSH that the neutron dose is generally greater under the lead apron, 

because it is held close to the body (where the albedo affect is greatest, due to the lower Z 

materials in the body), as opposed to being on the outside of the apron. Additionally, because 

lead is not a good neutron absorber, it does not attenuate the neutron dose significantly. 

NIOSH’s conclusions appear to be reasonable and are similar to the conclusions made at the 

Pantex plant in 1995 (Passmore 1995), except for the reduction of the photon dose by only 0%–

15% at RFP; Pantex reported a reduction of 57% in photon dose, which corresponds to an 

average energy of approximately 175 keV (GPO 1970, p. 138). Photons below about 40 keV 

would essentially all be stopped by 0.45 mm of lead. A brief summary of photon attenuation as 

derived from data in the Radiological Health Handbook (GPO 1970, p. 138) follows: 

 keV Attenuation 

 <40 100% 

 150 63% 

 200 40% 

 300 19% 

 400 11% 

 600 6% 

 700 5% 

Section 7.3.4.1, page 63, of the evaluation report recommends a photon energy range of 30–

250 keV. This would correspond to approximately 100% to 30% attenuation over this range of 

photon energies. In contrast, a photon attenuation of 15%, as recommended by NIOSH, would 
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correspond to an average energy of approximately 350 keV, and 8% would correspond to 

approximately 500 keV. NIOSH’s dose reconstruction Case C used a lead apron correction 

factor of 15% for penetrating dose to the head and 11% for shallow dose. 

SC&A Evaluation: SC&A agrees that adjustments for the wearing of lead aprons can be made, 

but does not currently see where the small adjustment factor of 0%–15% is appropriate for 

workers at RFP. Attachment 9 provides the SC&A analysis of NIOSH’s dose reconstruction 

Case C for a worker who wore a lead apron. While this is not an SEC issue, it is a concern for 

site profile dose reconstruction.

4.7 REVIEW OF THREE HYPOTHETICAL DOSE RECONSTRUCTION CASES 

NIOSH provided SC&A with three hypothetical external dose reconstruction cases (of six total 

examples, with the other three being internal cases) for review of procedures and methods. 

SC&A analyzed these three examples to determine if the external dose reconstructions were 

consistent with present guidelines and recommended procedures, and if sufficient data were 

available to allow for claimant-favorable dose reconstructions. SC&A reviewed each case with 

regard to applicable beta, photon, and neutron dose exposures; any data gaps, zero, or less than 

LOD readings; and any unusual exposure conditions. 

4.7.1 Case 1—Hypothetical Neutron Dose Assignment for Monitored Worker, Pre-1970 

This case provided an example of neutron dose reconstruction that involved use of the NDRP 

Report, ORAUT-OTIB-0050, and missed assignments for periods of blank entries. 

SC&A Evaluation: While NIOSH was able to provide a reasonable dose reconstruction for this 

case, there were several areas of concern: 

(1) A single n/p value of 0.42 was used for 1970–1976 (which was derived from later 1977–

2000 TLD data). 

(2) There is a question concerning the completeness of data for 1962–1969. SC&A found 

significant time gaps in dose data during its recent review of DOE files for 52 randomly 

selected RFP dose reconstruction cases. Therefore, the assumption that there is complete 

NDRP data for 1962–1969 may not be realistic for actual worker cases. 

(3) In this dose reconstruction case, there were 102 dosimeter cycles when a zero was 

assigned for photons and only 85 for neutrons. It is unusual to have more missing photon 

readings than neutron readings. 

(4) Assigning a missed dose based on LOD is not acceptable for unmonitored periods or 

lost/damaged/unreturned badges, as it in no way reflects the actual dose received. 
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(5) Although the conversion may be correct, it is not clear from the dose reconstruction how 

the 30–250 keV photon dose and the neutron dose were converted to organ doses using 

the dose conversion factors (DCFs) available. 

4.7.2 Case 2—Hypothetical Beta/Photon/Neutron Exposures with Use of Glovebox 

This case provided an example similar to Case 1 with the additional complexity of using a 

glovebox, which involves using OCAS-TIB-0010 (OCAS 2005) in the dose reconstruction. 

SC&A Evaluation: The same five concerns stated in Case 1 also apply to this case. 

Additionally, concerns about applying ORAUT-OTIB-0010 (ORAUT 2004c) need to be 

addressed. 

(1) The glovebox correction factor was applied to only 8 out of 30 years, although all records 

indicate that the energy employee worked most of the 30 years using a glovebox, where 

his prostate would have received a higher dose than indicated by dosimeters located on 

the trunk of his body. This would appear to underestimate the worker’s dose and is not 

claimant favorable. 

(2) The dose reconstruction case states, “The photon correction factor of 2.19 for photons 

and neutrons was applied to the selected years as provided in the Technical Information 

Bulletin: Special External Dose Reconstruction Considerations for Glovebox Workers” 

[emphasis added] (OCAS 2005). A search of ORAUT-OTIB-0010 (ORAUT 2004c) did 

not find any use of selected years. 

4.7.3 Case 3—Coworker Dose Assignment Needed for Some Years; Lead Apron 

Correction Factor Used 

This case is similar to Case 1, except it includes the use of lead aprons. The same five concerns 

stated in Case 1 also apply to this case. Additionally, the following concerns about correcting for 

the use of lead aprons need to be addressed: 

(1) The dose reconstruction of this case applied a correction factor of 1.15 to the reported 

deep dose and 1.1 to the reported shallow dose. These correction factors appear very 

small in comparison to the attenuation of low-energy photon in lead. Photon attenuation 

of 15%, as used in this dose reconstruction case, would correspond to an average energy 

of approximately 350 keV; however, the text in this dose reconstruction case assumes 

photon energy of 20 keV. 

(2) This dose reconstruction case refers to Table 6-8 in ORAUT-TKBS-0011-6, (DRAFT)

Technical Basis Document for the Rocky Flats Plant—Occupational External Dosimetry, 

Rev 01-Draft A, February 15, 2006. This new version of ORAUT-TKBS-0011-6 could 

not be found on the NIOSH/OCAS web site or the O-drive to verify the information used 

in the dose reconstruction. SC&A did find a Table 6-8 in the very recent release of 

Revision 01 of ORAU-TKBS-0011-6 (Langsted 2007). This table lists bias correction 
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factors for wearing a lead apron as 1 for shallow and deep photon doses for all cases, 

except when the badge was worn under the apron; the correction factor is 1.2 for deep 

dose in unprotected areas only. If the values in this table are correct, the energy of the 

photons must have been relatively high (>600 keV), and therefore, the apron was of no 

use if it did not attenuate the photon dose received by the dosimeter (which is to represent 

the dose that the body received). 

4.7.4 Summary of Dose Reconstruction Cases 

The preceding list of concerns emerged from analysis of the three hypothetical dose 

reconstruction cases to determine if the procedures were claimant favorable and reasonable. The 

results reflect some of the same issues identified by SC&A in the RFP site reviews for actual 

workers. Attachment 10 provides a detailed report of this evaluation. These concerns are most 

likely not SEC issues, but they need to be addressed from a site profile basis to ensure claimant 

favorability. 

4.8 SPECIFIC ISSUES 

The following are specific issues related to external dosimetry that were addressed during 

working group deliberations. A number of these are also addressed in Section 5.0, Data 

Integrity, for their data reliability implications. 

4.8.1 Workers’ Dosimeter Storage Location May Affect Reading 

 

The United Steelworkers of America Rocky Flats SEC-00030 Petition (USWA 2005) expressed 

concern that workers’ dosimeters were stored in areas that had above-normal radiation fields. 

The workers were concerned that their badges were stored during nonworking hours on the 

badge boards located near higher than background radiation fields. NIOSH responds to this 

concern on page 74 of the evaluation report (NIOSH 2006a), stating, “If the employee’s 

dosimeters were stored in a location where it was exposed to radiation, this exposure would 

cause his dosimeter badge to register additional dose that he didn’t actually receive.” 

SC&A Evaluation: SC&A has not found evidence that workers’ dosimeter badges were stored 

in higher than normal radiation areas. However, if they were, then the workers’ dose records 

would show a higher dose than the workers actually received, which would be claimant 

favorable. 

4.8.2 Improper Control Badge Storage 

The SEC-00030 Petition expressed concern that control badges were stored in areas that had 

above normal radiation fields. NIOSH states on page 76 of the evaluation report (NIOSH 2006a) 

that there is no evidence that an identified high-background radiation level was found. 

SC&A Evaluation: The SC&A review of available operational and radiological records has not 

corroborated this as an issue to date.
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4.8.3 Crystals on the Floor in Building 123 

The SEC-00030 Petition expressed concern that workers saw TLD chips on the floor of the 

counting room and that this could lead to unrecorded doses that workers actually received. 

NIOSH responds to this concern on page 75 of the evaluation report (NISOH 2006a), stating, “In 

these cases, a dose could be estimated from the readings from the remaining crystals.” 

SC&A Evaluation: SC&A agrees that this is normal dosimetry procedure whenever a chip or 

two are dropped or missing. However, if a whole tray of loose chips were spilled, then there 

would be no duplicate chips to read. Assigned dose would then depend on prior or post-dose 

readings and/or coworker data. However, exposures from incidents/accidents would not be 

properly recorded using these methods, unless accounted for by other means. 

4.8.4 Dosimetry Records from July through October 1984 

A group of dose records from July through October 1984 showed neutron dose entries but no 

gamma dose entries. Because this is an unlikely exposure condition, the SEC-00030 Petition 

highlighted this issue. NIOSH has determined that the problem with the dose calculation 

algorithm resulted in the recording of neutron doses that were evaluated as zeros as measured 

doses (i.e., greater than zero). This problem would result in overestimates of the neutron doses 

actually received during this brief period. 

SC&A Evaluation: In view of the information currently available, SC&A agrees with NIOSH’s 

proposed dose evaluation approach. 

4.8.5 Handling of Dense Neutron Film Results 

A possible problem was raised concerning dense neutron film evaluation mentioned in an RFP 

memorandum dated March 16, 1965 (Kirchner and Kittinger 1965). From the first paragraph of 

the memorandum, it appeared that if the NTA film was dense and neutron tracks could not be 

read, then a dose of zero was entered into the worker’s records. NIOSH analyzed the 

memorandum and related documents and concluded that a probable dose was assigned to the 

worker and that the zero entry referred to the fact that the IBM computer would have recorded a 

zero dose if further investigation was not conducted (Attachment 11). 

SC&A Evaluation: In view of the information and analysis provided by NIOSH, SC&A finds 

that dense neutron film did not preclude reasonable dose assignments in the workers’ records. 

4.8.6 External Dose Reconstruction Feasibility Conclusion 

NIOSH states on page 65 of the evaluation report that it has access to sufficient information to 

either (1) estimate the maximum external radiation dose for every type of cancer for which 

radiation doses are reconstructed that could have been incurred under plausible circumstances by 

any member of the class, or (2) estimate the external radiation doses to members of the class 

more precisely than a maximum dose estimate. 
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SC&A Evaluation: SC&A has found, with one exception, that NIOSH generally has adequate 

information to estimate sufficiently accurate external photon doses to members of a class of 

workers or estimate the plausible upper bounds for the maximum external photon dose if 

individual dose records are not available. SC&A understands that NIOSH will perform these 

dose reconstructions by using the individual dose records in the DOE files if available, or 

appropriate coworker data and model if individual dose data are not available. The exception 

relates to external dose data for nonplutonium workers for the 1950s. NIOSH has not 

demonstrated that it has the data to do a bounding dose analysis for all members of this group of 

worker; nor has it demonstrated that its coworker model is adequately bounding for these 

individuals. No documentation/data has been located to validate that use of the 1959 neutron 

data to estimate dose in the 1952–1958 period. 
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5.0 DATA INTEGRITY 

Data reliability issues figure prominently in the submitted SEC petition. The critical nature of 

such issues is acknowledged in the draft SEC review procedures of the Advisory Board, which 

recognizes that establishing data integrity and reliability is fundamental to dose reconstruction 

under EEOICPA and for evaluations of SEC petitions. 

Initially, SC&A was aware of and had access to the primary electronic database for RFP dose 

records, the HIS-20 database, as well as actual claimant dose records (through NIOSH). As the 

review progressed, additional sources of dose information were identified, including the 

Comprehensive Epidemiologic Data Resource (CEDR), a health research database; RFP 

logbooks, containing day-to-day operational exposure and dose entries; and specific programs 

and documents containing relevant data (e.g., the Neutron Dose Reconstruction Project, NDRP). 

The value of these alternative dose records, despite inherent limitations in many of them with 

respect to scope, completeness, and pedigree, is the ability to compare recorded doses for the 

same individuals as a means to validate the completeness and accuracy of these databases, and 

that there exists “sufficient information to estimate the maximum radiation dose,” as provided by 

42 CFR 83. 

At the January 27, 2006, working group meeting in Boston, SC&A noted the lack of 

corroborating evidence to back up assertions made by both the petitioners and NIOSH’s site 

experts regarding the pervasiveness of dose record discrepancies and their historic origins. In 

response, and under the charter of an ongoing site profile-based evaluation of SEC-related issues, 

SC&A decided to directly interview petitioners and other site experts on these concerns and to 

conduct document searches for such evidence at the Denver Federal Records Center. Following 

several weeks of contacts with the petitioners, SC&A (Kathryn Robertson-DeMers) conducted 

onsite interviews with the petitioners to clarify information and identify supporting 

documentation that could serve to resolve data reliability issues. SC&A also had the opportunity 

to interview additional individuals who expressed further concerns over issues documented in the 

SEC petition. One of the outcomes of these investigations was the identification of documents 

(in particular, logbooks and safety concern reports) that would prove useful in evaluating the 

merits of many of the data reliability issues raised in the petition. 

SC&A noted the lack of corroborating evidence to back up assertions made by both the 

petitioners and NIOSH’s site experts regarding the pervasiveness of dose record discrepancies 

and their historic origins. Under the broad guidance of the Advisory Board’s working group, 

SC&A decided to interview petitioners and other site experts directly on these issues and to 

conduct record reviews for such evidence at the Legacy Management’s Mountain View facility. 

Toward this end, SC&A conducted document searches, facilitated by Legacy Management prior 

to an onsite visit. Select records from document search results were requested and retrieved from 

the Denver Federal Records Center. During this visit, SC&A reviewed the contents of 

approximately 26 boxes. SC&A made subsequent records requests based on specific concerns 

raised during the interviews and reviewed the index of search results provided by Legacy 

Management for relevance. SC&A asked Legacy Management to pull additional items from 

subsequent reviews and provide a scanned image of the actual document to both 
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NIOSH/ORAUT and SC&A. After the initial visit, SC&A did not have access to the entire 

contents of the boxes but only to the specific documents within boxes. A complete list of search 

results provided by Legacy Management is given in Attachment 12. Many of the records proved 

not relevant to the SEC petition evaluation review and were not requested. 

As requested by the working group, SC&A provided a trip report (SC&A 2006a) regarding this 

initial records review on April 5, 2006. Although the initial SC&A review was preliminary in 

nature, it was done to convey progress in investigating RFP data reliability issues to support the 

time-sensitive SEC review process underway. To ensure coherency and relevance to the SEC 

review process, the report was organized to comment on, or respond to, specific data reliability 

issues expressed in the RFP SEC Petition. Some of the original issues were closed during 

working group discussions; however, five main concerns required considerable followup 

investigation: 

(1) Employee safety concerns 

(2) External dosimetry investigation processes and procedures 

(3) Review of field logbooks for information contradictory to dosimetry records 

(4) Destruction of records pertaining to personnel monitoring 

(5) Completeness of records provided for dose reconstruction 

Comments presented in this report are based on RFP documentation and technical reports as well 

as petitioner interviews. The discussion below takes into account responses received from 

NIOSH and the working group to date and comments made during working group meetings. 

Data Access 

On March 27–29, 2006, Kathryn Robertson-DeMers of SC&A traveled to Denver to meet with 

petitioners and review documents. Prior to her arrival in Denver on May 27, 2006, Legacy 

Management personnel conducted a records search. Based on the search results, SC&A 

requested some records of interest to be pulled from the Denver Federal Records Center for 

review. SC&A also identified and requested records from other sources. Additional searches of 

the records database were conducted while on site and after the visit. The records originally 

requested were of a broad nature and included technical reports, dosimetry processing logs, 

secondary dosimetry results, contamination control logbooks, dosimetry receipt logs, and 

dosimetry procedures. Prior to and during the site visit, SC&A chose records for review that it 

believed would help answer specific data reliability issues. For example, SC&A requested the 

dosimetry procedures in order to evaluate the process for assigning dose to workers in the case of 

damaged, lost, or overexposed dosimeters. Petitioners and their supporters also provided input 

regarding records that may substantiate data reliability comments made in the petition. Records 

not available during the visit were later retrieved. However, following SC&A’s preliminary 

review, NIOSH performed the actual review of this record set at the direction of the working 

group. 

In its response to SC&A’s April 5, 2006, trip report regarding falsification of records, NIOSH 

provided the following response (NIOSH 2006d): 
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In the absence of evidence to the contrary, NIOSH stands by our previous 

response. Although the petitioners have expressed concerns with the reliability of 

this data, to date no evidence other than worker affidavits has been provided that 

would support these concerns. In response to a letter to the petitioner dated 

March 16, 2006, requesting reports or citations supporting allegations of fraud in 

recording and reporting worker dosimetry results, the petitioner directed NIOSH 

to Freedom of Information Officer Lisa Bressler. Officer Bressler also directed 

us to a few other DOE and Kaiser-Hill personnel. NIOSH is currently continuing 

conversations with these additional personnel, but so far no evidence of criminal 

and/or fraudulent activities regarding dosimetry records has been located. 

During the course of interviews with petitioners, it became clear that their access to records was 

limited to Freedom of Information Act requests. The petition included only unclassified sources, 

primarily available through the United Steel Workers of America Local 8031or individuals. The 

petitioners were apparently aware of documents that could support petition issues; however, they 

have not had success in accessing them. 

From the interviews conducted and documentation obtained, data reliability issues continued to 

be of concern, consistent with specific examples provided in the petition: 

• Dose records containing blanks or “no data available,” especially in situations of high 

exposure 

• External dosimetry investigations related to damaged, lost, or overexposed badges 

• Alleged false entries in dose records 

• Incomplete dose records 

• Exposure to other radionuclides 

During the April 12, 2006, Advisory Board working group conference call, SC&A was asked to 

provide a list of the initial records requested from the RFP records center. In addition to this list, 

SC&A provided information on the relevance of outstanding records and how these records 

could be used to potentially answer data reliability issues. The working group assigned NIOSH 

to follow up on retrieval and review of these records (ABRWH 2006b). 

After its initial visit, SC&A conducted additional searches of the records database. Subsequent 

SC&A requests for records were more specific and were focused on particular data needs, such 

as retrieving information on the 1969 fire, D&D, and logbooks maintained by key radiological 

control personnel. SC&A requested this information not only regarding the data integrity issue, 

but also as documentation related to other findings in this report. For example, SC&A reviewed 

field logbooks for reference to other radionuclides to help determine timelines for the use of 

other radionuclides at RFP. 
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5.1 SAFETY CONCERNS 

5.1.1 Background 

During the course of interviews with RFP SEC petitioners and others, individuals stated that 

former supervisors had gone back and modified dose records by replacing positive doses with 

zeros. When asked by SC&A if they had corroborating documentation, the interviewees 

indicated they had filed formal safety concerns at the time. The petitioners provided SC&A with 

a hard copy list of safety concerns. This index, covering 1970–1992, gave only brief 

descriptions of each safety concern topic. It included concerns related to industrial, chemical, 

and radiological safety. Given the brevity of the interview visit, the petitioners shared several 

examples of safety concern files with SC&A. The safety concern files ranged from a single 

sheet where the issue was resolved on a one-page form, to several sheets where the issue was 

elevated to the Joint Company-Union Safety Committee (JCUSC). SC&A reviewed the safety 

concern list provided by the petitioners in order to corroborate the particular concerns cited by 

the interviewees, as one means to establish whether data reliability may be an SEC-related 

concern. 

In a May 2006 working group meeting on the RFP SEC, a petitioner indicated that Rocky Flats 

Environmental Technology Site (RFETS), the former operating contractor, once maintained a 

database of safety concerns that may date to before 1970. The Advisory Board working group 

asked NIOSH to determine whether such a database existed and, if so, whether it contained early 

safety concerns relevant to the petition evaluation. A database containing 4,946 safety concerns 

from 1970 to 2004 was subsequently located in the RFP archived records. The database did not 

contain any safety concerns identified for the years prior to 1970. NIOSH evaluated the database 

and identified 33 safety concerns that had potential relevance to the SEC. One safety concern 

was actually a subset of another safety concern. SC&A also evaluated the database of safety 

concerns and identified an additional 17 relevant safety concerns. The documentation pertaining 

to specific safety concerns (that would have relevance to specific SEC data reliability issues) was 

requested from Legacy Management and imaged copies were provided to NIOSH. The safety 

concern files include the original safety concern filed by the employees, a supervisory response, 

and documentation relating to resolution of the safety concern. 

NIOSH completed a review of 49 of the safety concern files and provided the analysis to SC&A 

on October 27, 2006. The evaluations for Safety Concerns 90-169 and 92-048 remain ongoing 

(JCUSC 1990b, JCUSC 1992c). One safety concern was identical to another and was 

renumbered by JCUSC. The NIOSH evaluation concludes that the safety concerns with 

complete reviews do not have a bearing on the data integrity issues included in the petition, and 

they do not affect the ability to conduct dose reconstruction. NIOSH has indicated that 

techniques can be used to assign the missing dose. For example, bioassay data before and after a 

data gap can be used to assign internal dose during the period of time when bioassays were not 

collected. 

Safety concerns identified covered a wide range of subject matter, with some issues closely 

related to concerns raised in the SEC petition. The time period of the safety concerns range from
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1970–2000, with a majority from the 1990s. A few concerns raised questions regarding the 

accuracy of the personnel monitoring program (internal and external). Other concerns relate to 

the adequacy of the bioassay program in effectively monitoring personnel routinely and for 

incidents. Several safety concerns were related to RFP external dosimetry policies and practices, 

including badge exchanges, dosimeter storage, contaminated dosimeters, and unauthorized 

practices. Several of the documents discussed general health physics issues, such as the lack of 

radiation protection technician (RPT) coverage, or noncompliance with procedures. 

5.1.2 Analysis 

SC&A has reviewed the safety concerns and the NIOSH position related to each safety concern. 

Attachment 13 provides a list of the safety concerns evaluated, including a description of the 

concern, the NIOSH position related to the safety concern, and the SC&A response. The review 

involved evaluation of the safety concern file as well as the response documented by NIOSH in 

NIOSH Evaluation of Specific Safety Concerns (NIOSH 2006e) and NIOSH Evaluation of 

Specific Safety Concerns Set 2 (NIOSH 2006f), provided to the working group and SC&A on 

August 28, 2006, and October 31, 2006, respectively. Safety concerns were considered 

inconclusive when key information important to resolving individual radiation exposure under 

the circumstances was not available in the file. For example, individuals expressed concerns 

about high radiation exposures, but their monitoring status remains unknown. In two cases, 

NIOSH did not specifically evaluate the data reliability issues presented in the safety concern. In 

these cases, SC&A prepared an evaluation of the relevance of the issue with respect to 

falsification of records, dosimetry investigations, and inadequate or incomplete dosimetry data 

and records. This review includes this evaluation. 

In its evaluation, SC&A divided the safety concerns into three categories in relation to the SEC 

petition. First are those safety concerns that are not relevant to or bear on NIOSH’s ability to 

adequately conduct dose reconstruction; these include concerns such as those related to 

nonradiological safety issues, hostile work environment, instances when individuals were 

monitored based on the particular event, lack of communication, and lack of training. Second 

are issues associated with the processing of dosimeters when the dosimeter or dosimeter 

components were lost, damaged, or overexposed, or exhibited other problems. The third group 

includes safety concerns that, in SC&A’s view, reinforce claims and statements made in 

affidavits or public comments. NIOSH continues its investigation of two safety concerns 

involving lost or invalid bioassay results (90-169) and the inadequacy of the internal and external 

dosimetry programs (92-048). 

5.1.3 Inconclusive Safety Concerns 

Three safety concerns (89-259, 94-245, 95-061) and a portion of two additional safety concerns 

(91-395, 91-496) were considered inconclusive because key information to make a determination 

was not included in the file provided by RFP. 

Safety Concern 89-259 expresses a concern related to the accuracy and trends in cumulative dose 

(JCUSC 1989a). The issue was not clearly defined, making it difficult to ascertain whether the 
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issue was directly related to dosimetry or whether it was associated with the health physics goal 

of monitoring radiation exposures “as low as reasonably achievable” (ALARA). Safety Concern 

91-395 states that radiation exposures to employees in Building 664 were too high and 

unnecessary because grams of plutonium, americium, and uranium were being stored in drums at 

this location (JCUSC 1991a). It is unclear whether personnel in the building were required to 

wear dosimetry prior to the establishment of a radiological control area (RCA), or whether the 

RCA was created prior to the drums arriving. NIOSH has assumed that this is not an SEC issue; 

however, without the information discussed above, it is unclear how it was able to come to this 

conclusion. 

 

Safety Concern 91-496 specifically expressed concern regarding the lack of background studies 

conducted prior to locating the badge storage rack in the tunnel north of Portal 1 (JCUSC 

1991b). There was an underlying concern that the radiation and environmental conditions at this 

location were not appropriate. For periods of time when location-specific backgrounds were 

used in background subtraction, the safety concern is inconclusive. There is no indication how 

the background radiation level changed, and if adjustments were applied to retrospective data. 

For those years when environmental dose levels were used for background subtraction, the 

location of the dosimeter storage areas would not affect the dosimeter results. 

Safety Concern 94-245 involves the confiscation of the TLDs of two workers as a result of safety 

violations (JCUSC 1994a). NIOSH indicates that performing work without appropriate 

dosimetry in an RCA may or may not affect the ability to perform dose reconstruction. It further 

indicates that the employees with confiscated TLDs did not work in an RCA while they did not 

have a TLD. There seems to be some disagreement regarding this fact. The employees indicated 

that they did perform radiological work during this time period while JCUSC indicated the 

employees were not required to perform work in a radiological area without a TLD during this 

time period. The safety concern file did not include any details regarding the JCUSC 

investigation. In addition, this safety concern raises the questions of how frequently TLDs were 

taken away from workers and why. Were these workers prevented from entering radiological 

areas during this time period? Certainly, if employees were entering radiological areas without 

TLDs, this would put their amount of external exposure in question and therefore impact dose 

reconstruction. NIOSH assumes the worker did not enter a radiological area. In SC&A’s view, 

not enough information is provided in the safety concern file to make this determination. 

Safety Concern 95-061 discusses a situation where the building manager pulled TLDs from 

workers in Building 776 as a result of a radiation work permit (RWP) violation (JCUSC 1995a). 

There is no indication whether individuals having their dosimeters pulled were accordingly 

banned from entry into the RCAs. The larger concern is whether a simultaneous restriction from 

radiation areas was enforced. The safety concern did not indicate what restriction was imposed 

on personnel. Without complete information on these issues, no clear determination can be made 

with regard to whether they represent data integrity problems. 
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5.1.4 Safety Concerns Not Affecting the Dose Reconstruction Process 

Several of the files reviewed were concerned with field radiological control conditions and not 

directly related to dosimetry results. Safety Concern 70-2 related to general area radiation levels, 

adequacy of shielding, storage of plutonium, dry box damage, and inadequacies in criticality 

drains (JCUSC 1970). As NIOSH indicated, these are important to the health and safety of 

workers; however, individuals in these areas would have been monitored for internal and 

external exposure. This safety concern indicates that high dose rates were expected for some 

groups, and that established administrative exposure levels were exceeded. This would not 

affect dose reconstruction since these individuals were monitored. Table 5-1 provides the 

number of individuals who exceeded an annual dose of 5 rem. These data were compiled by the 

RFP for the period 1951–1986. 

 

Table 5-1. Exposures in Excess of 5 Rem from 1951–1984 

Dose Range (Rem) Number of Individuals Exposed 

at This Level 

5–6 184 

6–7 59 

7–8 34 

8–9 14 

9–10 6 

10–11 4 

11–12 2 

Source: RI 1987 

General area doses rates will be further discussed in the Section 5.5.2, Badge Results Not 

Reflective of Field Exposure Conditions. 

Safety Concern 71-7 related to the inaccuracy of the stack air sampling results because 

appropriate procedures were not followed by RFP staff (JCUSC 1971a). This concern addressed 

environmental monitoring issues, which have implications for environmental dose. 

Environmental dose will be discussed in the extended review of the RFP site profile review. 

Issues of job coverage, inadequate notification of health physics staff, violation of procedures, 

and inadequate field monitoring were raised in Safety Concerns 85-137, 86-186, part of 91-496, 

93-124, and 94-080 (JCUSC 1985a, JCUSC 1986a, JCUSC 1991b, JCUSC 1993a, JCUSC 

1994b). Although important to a functional radiological control program, these concerns were 

not directly related to personnel monitoring and dose reconstruction. Other concerns addressed 

logbook entries for the contents of a tanker truck, hostile work environments, lack of showering 

facilities and emergency response kits, and inappropriate labeling of confidential information 

(JCUSC 1989e, JCUSC 1994c, JCUSC 1994d, JCUSC 1994e, USWA 1997, JCUSC 1999a, 

Anonymous 2000). Safety Concern 95-077 dealt with the appropriate procedure for shipping 

urine samples through the mail (JCUSC 1995b). Safety Concern 89-148 relates to the lack of 

procedures available for documenting infractions in radiation monitoring reports (JCUSC 
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1989b). These concerns were not directly related to personnel monitoring or dosimetry 

documentation. 

Safety Concerns 87-206 and 92-036 (JCUSC 1987a, JCUSC 1992a) brought up issues with the 

timeliness off issuing external dosimetry supervisory reports. The lapse of dosimeter exchange 

on the part of external dosimetry staff was raised in Safety Concern 86-13, and the timeliness of 

processing was raised in Safety Concern 96-182 (JCUSC 1986b, JCUSC 1996). Although less 

frequent exchange may cause additional uncertainty in the evaluation of the badge (e.g., fading 

considerations, appropriate background subtraction), it does not constitute an unmonitored 

situation. The lack of proper distribution of dosimeter results to the field (e.g., supervisor 

reports) was primarily related to the ALARA program for minimizing worker radiation 

exposures below external dose limits. The JCUSC raised the issue of manpower shortage in the 

dosimetry department in Safety Concern 86-13, indicating that the department delayed the usual 

dosimeter pickup schedule and thus processing for lower risk groups (e.g., during the third 

quarter of 1985) (JCUSC 1986b). This delay in badge processing may make comparisons being 

conducted in other areas of this review difficult. In addition, the timely processing of dosimeters 

is of some concern because backlogs may lead to practices such as not reading dosimeters from 

perceived low exposure groups. This occurred for some workers assigned to the so-called “cold 

area,” where radioactive material was, in fact, handled. This directly relates to the establishment 

of coworker dose. Safety Concern 75-34 related to the adjustment of dosimeter results after 

administration of a medical isotope (JCUSC 1975). If an investigation was conducted to 

determine the appropriate dose, this practice is reasonable. Safety Concern 90-202 related to 

questions posed to dosimetry staff about potential exposure from the Cf-252 calibration source 

(JCUSC 1990a). RFP dosimetry determined that the individuals of concern were monitored for 

both beta/gamma and neutron exposure. These data can be used in dose reconstruction. 

With regard to dosimeter background concerns, the radiation background at the Dosimeter 

Exchange Board is monitored by a TLD placed in the rack along with those worn by personnel. 

The methodology used for background subtraction has varied over time. Lagerquist (1975b) 

indicated that, effective January 1986, the total background subtracted from dosimeters would be 

environmental background (0.34 mrem/day) with instrument background. TLD operating 

procedures in 1983 also indicated that the total background subtracted was determined from 

environment and instrument background (RI 1983). The Background Subtraction Methodology 

Study was conducted by Klueber and Savitz (1999) the second quarter of 1999 at locations across 

the site. This study indicated that using a location-specific background may create potential 

problems because the dosimeters were not always stored at the assigned location. Furthermore, 

the study indicated subtracting backgrounds by location will generally reduce the reported dose 

(Klueber and Savitz 1999). A TLD background subtraction based on whether the location of the 

storage area was in a hard-walled or non-hard-walled building was implemented (RMRS 1999). 

A changed in background subtraction methodology occurred in 2001 when the actual TLD 

element residual signal together with a time-dependent and location-dependent background 

resulted in a TLD-specific background, which is subtracted from the dosimeter (RFETS 2001). 

Methods for background subtraction prior to 1976 were not located. The concerns around this 

issue relate to whether the location-specific background level is appropriate for background 

subtraction. Based on the documentation reviewed, the location-specific background was not 
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used at RFP until 1999. Background subtraction is more appropriately addressed as a site profile 

issue. 

Safety Concern 91-262 questions the practice of wearing dosimetry only when entering RCAs 

(JCUSC 1991c). The potential for worker involvement in a criticality was of particular concern. 

There are other means of determining doses for cases in which dosimeters are not worn during a 

nuclear criticality, as demonstrated with the Y-12 criticality accident in 1958. The JCUSC 

agreed with the employee that dosimeters should be worn at all times when in the perimeter 

security zone (PSZ). The operations group expressed concerns that this was not consistent with 

the health and safety procedures. HSP 18.07, External Radiation Dosimetry, updated June 15, 

1991, shortly after the safety concern was issued, continued to require that dosimetry be worn in 

RCAs or when posting required it, and that dosimeters be stored on badge racks (EG&G 1991). 

The safety concern did not discuss the relative exposure in uncontrolled areas of the building. 

Available area dosimetry systems could be used to assign a dose for those not required to enter 

radiological areas, assuming the exposures to the area badges and the personnel are equivalent. 

5.1.5 Processing of Lost, Damaged, Overexposed, or Otherwise Compromised Dosimeters 

Safety Concerns 85-161, 87-005, 87-038, and 91-490 relate to methods utilized to conduct 

external dosimetry investigations and provide other examples of individuals questioning the 

accuracy of the dosimetry system (JCUSC 1985b, JCUSC 1987b, JCUSC 1987c, JCUSC 1991d). 

Extended external dosimetry investigations are documented in personnel dosimetry files back to 

the mid-1980s; however, their availability in radiation dose files was not routine until the late 

1990s. 

Safety Concern 85-161 speaks to the conduct of external dosimetry investigations for questioned 

doses (JCUSC 1985b). Not enough information is available to determine whether this was a 

sitewide policy; however, the safety concern provides an example of a case for which a 

dosimetry investigation was conducted. It is difficult to determine from a secondary source 

whether an adequate investigation was conducted and whether the response was appropriate to 

the employee’s concerns. 

In Safety Concern 87-005 (JCUSC 1987b), a memorandum from R.N. Chanda and G.A. 

Overholt to P.A. Madsen (Chanda 1987) indicates that a review of the dosimetry records was 

conducted, and it was determined that the zeros were the result of an individual turning in wrist 

dosimeters without corresponding body dosimeters. This individual was assigned to the 

nondestructive assay group in Building 371, where there was a potential for exposure. It is 

difficult to determine from a secondary source whether an adequate investigation was conducted 

and whether the response was appropriate to the employee’s concerns. Direct data should be 

evaluated in this case, and the individual’s dose should be compared to that of his coworkers 

performing the same tasks. 

Safety Concern 87-038 involved modification of the dosimeter value due to QC issues with the 

dosimetry results (JCUSC 1987c). No followup investigation of the individual’s potential 

exposure appears to have been conducted. This is directly related to the issue of how dose was 
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assigned when dosimeters were lost, damaged, or contaminated, or had QC problems. The 

individual was on a biweekly exchange schedule, indicating the potential for higher exposure. 

The adjustment to his dose does not reflect this, and adequate justification for this dose is not 

provided. Questionable data of this type should not be used in dose reconstruction. 

Safety Concern 91-496 discussed the employee’s responsibility to protect his or her dosimeter 

from contamination, tampering, misuse, and other compromising situations (JCUSC 1991b). 

With respect to positive control, no system was in place to prevent individuals from tampering 

with dosimeters. RFP external dosimetry staff members indicated they evaluated the raw results 

from each element as an indication of inappropriate dose results. The safety concern did not 

address the specific process followed by external dosimetry staff to identify and investigate 

inappropriate dose results. 

5.1.6 Safety Concerns Consistent with Statements in Affidavits or Public Comments 

SC&A has determined that Safety Concern 71-4 does not provide conclusive evidence of a 

sitewide issue. It does, however, provide an example of a situation where the worker believed 

dosimeter badges were not adequately capturing the actual exposure conditions. The safety 

concern, itself, stated the following (JCUSC 1971b): 

My film badge results for Dec. 1970 did not show the high level of neutron exposure which[,] 

according to instrument readings and film badge results of other monitor[s] on the same special 

job, should have been expected. 

This safety concern mirrors the concerns cited in former RFP worker affidavits that their 

dosimeters did not reflect actual exposure conditions. The supervisor’s response indicated there 

was an inherent inaccuracy with neutron film dosimetry, and that neutron TLDs were scheduled 

to replace neutron film. No explanation was given for the failure of the worker’s film badge to 

reflect his coworkers’ doses or instrument readings. The petition includes affidavits from 

employees documenting similar concerns. 

Safety Concern 74-61 indicated there was a need for quantitative assessment of radioactive 

material within the body (JCUSC 1974). Further discussion with RFP radiological control staff 

having knowledge of this safety concern indicated that the concern was particularly directed at 

the in-vivo counting system. NIOSH has indicated that in-vivo counting results are not used in 

its analysis of claimant dose. If this is the case, and individuals were adequately monitored via 

urinalysis, NIOSH could use bioassay data for dose reconstructions. If, however, NIOSH 

decides to use lung count data to “bound” intakes, or it is determined that bioassay monitoring 

was incomplete, this would impact internal dose reconstruction. Furthermore, if the coworker 

model uses these data, the reliability of these data is in question and must be evaluated further. 

The concern clearly shows that some workers, even within the radiological control organization, 

questioned the results they received from dosimetry. Whether dosimetry data were inadequate 

cannot be determined from the information in the safety concern. This lack of faith in dosimetry 

results has been raised several times throughout the petition. The safety concern provides a 

historical reference to these concerns. 
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Safety Concern 89-037 involves the lack of internal and external monitoring for an employee 

who worked in the uranium area (JCUSC 1989c). It provides an example of a situation in which 

missed dose is possible. NIOSH has generic methods for assigning dose where data gaps exist; 

however, the exact method for addressing data gaps is still under consideration. Of particular 

concern is NIOSH’s method for identifying data gaps and assigning dose for multiple-year data 

gaps. Although lack of monitoring is not, per se, a data integrity issue, it does have a significant 

impact on dose reconstruction. In addition, gaps in the data of individuals exposed, but not 

adequately monitored, cast doubt on the integrity of the data made available for dose 

reconstruction. 

Safety Concerns 84-19 and 86-161 discussed apprehension related to abnormally high or positive 

in-vivo bioassay results (JCUSC 1984, JCUSC 1986c). Safety Concerns 84-19, 86-169, 89-167, 

93-061, 93-193, and 99-013 raised questions regarding the timeliness of bioassay collection or 

communication of results (JCUSC 1984, JCUSC 1986d, JCUSC 1989f, JCUSC 1993c, JCUSC 

1993b, JCUSC 1999b). Safety Concerns 85-109, 89-203, and 92-003 questioned inconsistencies 

in instrument results (e.g., wound counting) or malfunctions in equipment (e.g., in-vivo counter) 

(JCUSC 1985c, JCUSC 1989d, JCUSC 1992b). Although delaying communication of bioassay 

results and subsequent dose assessments is a poor practice, it does not preclude dose 

reconstruction. Untimely bioassay turnaround times delay the collection of followup samples 

and complicate the determination of intake conditions. Furthermore, this is not conducive to a 

good ALARA program. Delaying bioassay, whether urine or fecal, or in-vivo counting for a few 

days does not prevent the detection of long-lived insoluble radionuclides taken into the body. 

For soluble material such as tritium, delay in bioassay may affect the ability to detect an 

incidental intake depending on the length of the delay. Assuming the employee was adequately 

monitored via urinalysis, and in-vivo counting was not used in dose reconstruction, these issues 

would not present a problem for dose reconstruction. If, however, NIOSH decides to use lung 

count data to “bound” intakes, or it is determined that bioassay monitoring was incomplete, this 

would impact internal dose reconstruction. Furthermore, if the coworker model uses these data, 

the reliability of these data is in question and must be evaluated further. 

Safety Concern 97-176 demonstrates the lack of proper QC within the dosimetry processing 

laboratory (JCUSC 1997). An employee was given a TLD badge that did not contain 

thermoluminescent elements. The TLD had been processed, but the elements were not replaced 

at the time the supervisor retrieved the dosimeter. The radiological control technician (RCT) 

entered radiological areas with inadequate dosimetry (Baker 1997). This is one of many QC 

problems encountered by external dosimetry staff throughout RFP operational history. 

Safety Concern 98-073 relates to multiple employees working in Building 374 who questioned 

the accuracy of the monitoring program (JCUSC 1998). RFP dosimetry provided an evaluation 

of dosimetry results for the particular department that these employees worked in; however, no 

information was provided for specific individuals to allow a comparison to previous exposures. 

The external dosimetry department looked at the dosimetry results of process specialists and 

RCTs for the fourth quarter of 1997 and the first quarter of 1998. Dosimetry indicated that dose 

for 12 process specialists went down, dose for 7 process specialists went up, and dose for 3 

individuals stayed the same. For the same time the RCT doses decreased. The average dose for 
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process specialists averaged 9.8 mrem in the fourth quarter of 1997 and 6.1 mrem in the first 

quarter of 1998. It is difficult to ascertain whether there is evidence of inaccuracies in individual 

files based on a population evaluation that appears to be inconclusive. NIOSH has provided a 

general hypothesis that inaccuracies did not exist without substantiating it by looking at 

individual cases. Some basis for this hypothesis should be documented. 

NIOSH, in other cases, also provides such hypotheses in response to specific concerns without 

what SC&A views as an adequate basis or substantiation. In several instances, a broader 

conclusion regarding sitewide data integrity is made on the basis of an unsubstantiated 

hypothesis. For example, in relation to Safety Concern 89-037, NIOSH stated the following 

(NIOSH 2006f): 

In any event, this appears to be an example of an isolated failure to follow established 

policies. Corrective actions were taken, and there is no indication that this event 

constitutes a sitewide data integrity issue, and does not have SEC implications. 

During review of logbooks, the following entry was found, related to an incident involved four 

RCTs: 

...do not have dosimetry badges on the board this morning...told to report to 

class then go to external dosimetry to get badge. Problem is movement of RCTs 

between buildings, but no paper work sent to change badge board locations. 

This indicates that RFP site dosimetry staff was not always aware of facility changes made by 

workers and may not have adjusted the worker’s monitoring in a timely manner. Although the 

logbook entry itself does not provide conclusive evidence of a sitewide issue, it certainly 

indicates that NIOSH may not be correct in its hypothesis that Safety Concern 89-037 is an 

isolated failure. 

The individual safety concerns reviewed did not include any information that taken together 

would conclusively demonstrate a sitewide issue with data integrity. However, the concerns 

raise numerous specific examples that bring into question the accuracy of the internal and 

external monitoring program. Some of these concerns were documented well before the 

enactment of EEOICPA, underscoring that a number of these concerns were not new. 

5.1.7 Safety Concerns Needing Further Basis or Investigation 

NIOSH has indicated that Safety Concerns 90-169 and 92-048 require further investigation to 

determine their relevance to the SEC petition. In Safety Concern 90-169, the worker submitted 

multiple urine samples, including samples sent off site (JCUSC 1990b). He was told that the 

first sample was negative. Additional samples were collected. Some samples were lost and 

another was invalid due to poor chemical recovery. This safety concern appears to provide an 

example of QC issues in the bioassay laboratory. This may or may not affect multiple 

individuals depending on the extent of the bioassay laboratory problems. Safety Concern 92-048 

questions the adequacy of the internal and external dosimetry programs at RFP and their 
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compliance with federal requirements (JCUSC 1992c). It further expresses concern over the lack 

of communication between dosimetry staff and the workforce. 

5.1.8 Summary 

The safety concerns evaluated provide multiple examples in which radiological control staff 

would presumably have conducted extended external dosimetry investigations. However, it is 

difficult to determine from a secondary source whether an adequate investigation was conducted 

and whether the investigation was responsive to the employees’ concerns. A review of former 

workers’ health physics files found evidence that extended external dosimetry investigations 

were documented back to the mid-1980s; however, the documentation did not routinely appear in 

the worker’s file until the late 1990s. This raises an unresolved concern as to whether external 

dosimetry investigations were conducted routinely prior to the late 1990s and, if so, why 

documentation is apparently absent from the health physics file.

A number of safety concerns (74-61, 85-109, 86-13, 86-161, 86-169, 89-037, 89-203, 90-169, 

91-496, 92-003, 92-048, and 97-176) relate to the lack of QC in the internal and external 

monitoring programs. These concerns collectively reinforce issues raised in the petition 

regarding data quality. For example, the NDRP is provided in the petition as an illustration of 

petitioner concerns over data quality issues. The NDRP was initiated as a result of questionable 

accuracy and completeness in neutron dosimetry from 1952 through 1971 (Baker 2002). Other 

examples of QC issues in the dosimetry program included computer algorithm and transfer errors 

(RI 1976, Baker 1998), not adjusting monitoring requirements for employees transferred to other 

areas of the site, loss of bioassay samples, double background subtraction for dosimeters (Savitz 

1996), and failure at blind audits (Klueber 1997). SC&A provides a generalized evaluation 

related to the completeness and accuracy of dosimetry results in its data integrity evaluation, as 

well as in Sections 4.0 and 8.0 of this report; an evaluation of dosimetry investigation procedures 

will be provided in Section 5.2, as well. 

Safety Concerns 90-169 and 92-048 should be investigated further to ascertain their applicability 

to the SEC petition. The lack of trust in the internal and external monitoring programs and 

dosimetry systems exemplified in these safety concerns is the fundamental issue raised by the 

petitioners. 

In conclusion, SC&A concurs with NIOSH’s assessments of many of the 49 safety concerns 

(excluding duplicates) and parts of other safety concerns. While these safety concerns do not 

directly address falsification of records, a number of them express a lack of confidence in the 

monitoring at RFP. Although the safety concerns do not provide definitive evidence of a 

systemic problem with RFP radiation dose data that would necessarily preclude dose 

reconstruction, some of them do highlight historic instances of poor QC practices. 

5.2 EXTERNAL DOSIMETRY PROCEDURES AND INVESTIGATIONS 

Two affidavits in the RFP SEC petition raised questions regarding the processing of dosimeters 

when the dosimeter or its components were lost, damaged, overexposed, or otherwise 
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compromised. The SEC petition raised concerns regarding crystals falling on the floor, crystals 

being discharged and reused, crystals being soaked in alcohol, and supervisors asking dosimetry 

workers to change or delete readings which were in the supervisor’s judgment “too high to 

possibly be correct” (USWA 2005, Part B, page 500). For example, a former RFP janitor 

recalled that the TLD chips would occasionally dislodge and end up on the floor. When the 

sweeping was completed, the dosimetry staff sifted through the sweepings to recover lost chips. 

Approximately 6 to 12 chips were found per day. A second affidavit indicates that at times the 

TLD reader would fail while the crystal was being read and the data were lost. Another concern 

related to the breaking of crystals dropped on the floor. Furthermore, the individual preparing 

the affidavit indicated, “Once these TLDs were heated to a certain temperature, they came out 

zeroed, so essentially no dose could accurately be reconstructed. When I asked Steve Baker how 

he handled that, he told me that he applied a “Fudge Factor” to assess dose” (USWA 2005, Part 

B, page 501). Based on these concerns and those raised by petitioners regarding the lack of 

agreement between field conditions and dosimeter results, an analysis of the external dosimetry 

data integrity and methods for dosimetry investigations was conducted by SC&A. 

Both SC&A and NIOSH conducted records searches to locate procedures relevant to the 

dosimetry process, raw dosimetry logs, and other documentation. NIOSH located three 

procedures related to dosimetry processing and investigations: (1) 4-J88-RDE-0053, TLD Data 

Investigation and Abbreviated External Dose Reconstruction (RFETS 1997a), (2) 4-J98-RDE0071, Extended External Dose Reconstruction (RFETS 1997b), and (3) External 

Thermoluminescent Dosimetry (TLD) (RI 1983). Several requests generated by radiological 

health staff in 1990 and 1991 requesting that field radiological control staff investigate unusual 

dosimeter results were located; however, information about the actual investigation was not 

available. The field radiological control staff was asked to perform an investigation in 

accordance with American National Standards Institute (ANSI) N13.6-1966, 1989 revision, 

(ANSI 1989) which provides general guidance on appropriate use of dosimetry, and return the 

results on a form to external dosimetry staff. The exact year when this was implemented is 

unknown. 

An effort was made by SC&A to pull dosimetry processing logbooks to identify particular 

situations where dosimetry investigations should have been completed (by current standards), 

evaluate whether the investigations were documented, and determine whether an appropriate 

methodology was applied for dosimetry investigations. During the records review, the 

1985/1986 Dosimetry Problem Logbook was located, reviewed, and copied (RFP 1986). This 

logbook contained employee numbers, assigned doses (shallow, penetrating, neutron and/or 

extremity), and the particular problem with the TLD (e.g., absence of crystals, contamination, 

processing error). As a means to determine if appropriate investigations were conducted, 

especially in the case of zeros or blanks, SC&A was asked to provide employee numbers for a 

subset of individuals listed in the 1985/1986 Dosimetry Problem Logbook to NIOSH. SC&A 

provided the requested information on the selected individuals to NIOSH in RFP Data Integrity 

Process May 19, 2006 for further evaluation (SC&A 2006b). The recommendations provided to 

the Advisory Board and NIOSH in the report regarding followup activities are outlined below: 
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1. NIOSH should evaluate how doses were assigned under conditions where 

there were dosimetry problems, how or whether the dose assignment method is 

documented, and whether the final dose assignment was valid using 

individuals listed in Table 2 as examples. 

2. NIOSH should do a similar analysis to the one suggested above for the 

Harshaw TLD and film time period inclusive of all general plant areas.

In NIOSH Evaluation of SC&A’s Draft Report on External Dosimetry Procedures, NIOSH stated 

the following (NIOSH 2007e): 

The Working Group has chosen to evaluate the reliability of the radiation files for 

use in dose reconstruction has been pursued in other ways, most specifically, in 

extensive comparisons of the information in the workers’ radiation files to 

information in logbooks, and through an examination of the completeness of 52 

individual workers radiation files. 

The 1985/1986 Dosimetry Problem Logbook does address completeness of individual files, but it 

also provides information for evaluating the dosimetry investigation process. Since petitioners 

have indicated that records have been falsified, this is one mechanism for evaluating whether 

there was justification for the questioned doses in the dose of record. 

5.2.1 External Dosimetry Processing Issues 

The affidavits summarized above raised concerns regarding the process for determining doses 

when crystals from the TLD system were dropped, damaged, or discharged as a result of reader 

malfunction or error. In NIOSH Evaluation of SC&A’s Draft Report on External Dosimetry 

Procedures, NIOSH provides one possible solution in a situation where crystals are dropped or 

discharged prior to obtaining a reading (NIOSH 2007e): 

It is possible that these crystals were read before they were dropped, but some 

crystals could have been dropped before being read. Systems were in place to 

interpret a badge with a missing crystal, and badges contained duplicate crystals. 

In these cases a dose could be estimated from the readings from the remaining 

crystals. These situations were investigated, and the procedures for doing so 

were formalized in 4-J88-RDE-0053, “TLD Data Investigation and Abbreviated 

External Dose Reconstruction” and 4-J98-RDE-0071, “Extended External Dose 

Reconstruction.” The results of these investigations were documented in the 

worker’s Health Physics file, and may or may not have been communicated to the 

employee at that time. Since instances where badges were missing crystals were 

investigated, NIOSH concludes that this issue does not prevent NIOSH from 

performing dose reconstructions of sufficient accuracy. 
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The report also states the following: 

If only a portion of a broken crystal is read, it is appropriate to apply a factor 

based on the size of the crystal remaining, to estimate the dose that crystal 

received. Not all information from the badge is lost if one chip is unreadable and 

a dose estimate can be made from the remaining crystals. 

SC&A concurs with the application of a correction factor for broken chips. It is appropriate to 

apply a correction factor based on the size of the broken fragments processed, assuming a 

reasonably accurate assessment of the size can be determined. A dosimetry investigation could 

also be conducted in this case to substantiate the calculated dose. The use of alcohol for cleaning 

the crystals prior to processing addresses concerns regarding contamination, such as by oil and 

hair, on the chips. Petitioners also stated that supervisors asked dosimetry workers to change or 

delete readings. Section 5.5 of this report addresses this issue. 

SC&A selected a subset of entries for individuals from the 1985/1986 Dosimetry Problem 

Logbook, which are provided in Table 5-2. The health physics files associated with these 

individuals were retrieved from RFP for comparison to the logbook entries. 
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Table 5-2. Individuals with Documented Dosimetry Problems during the Period from March 1985 t

(selected from RFP 1986) 

Case 

Number Date Justification for Change 

Dose 

Investigation 

Report 

Consistency 

of Doses SC&A 

1 4/19/1985 

Pen1.xtal >> skin, can’t happen [i.e., penetrating results were higher then skin 

results] 

N IC The value recorded in 

than that observed in The value in the logbthe second quarter rea

2 5/15/1985 Contamination in crystal holder N C 

The value recorded in than that observed for 

dosimetry file. 

3 5/16/1985 Problems with hot gas reader N IC 

Although the values pexceeded those for threadings, review of th

is recommended. 

4 6/10/1985 E/E2 ratio off N IC 

Although the value fothe logbook was grea

fourth quarter of 1985 result available in the Review of the specifirecommended. 

5 7/1/1985 Bad crystal N IC 

The logbook value wprocessing value from 

followed the date of cspecific processing da

6 7/2/1985 No crystals N IC 

The logbook value agfor the August 15, 19

7 8/30/1985 Beta reported where no beta exists N Y 

The logbook values adose from the fourth q

8 10/31/1985 Negative neutron ratio N Y 

Logbook values were both the fourth quarte

quarter of 1986. 

9 12/31/1985 Pen1 and skin crystals burned N IC 

10 12/31/1985 Reader problems on PMT N IC 

The logbook value wcopy penetrating dose 

1985 and the first qua

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Table 5-2. Individuals with Documented Dosimetry Problems during the Period from March 1985 t

(selected from RFP 1986) 

Case 

Number Date Justification for Change 

Dose 

Investigation 

Report 

Consistency 

of Doses SC&A 

The logbook values wwere not converted to 

the specific processin

11 2/28/1986 700 and 600 switched N IC 

The logbook value wFebruary 1986 hard c

with the March 1986 of the specific proces

12 2/28/1986 Bad crystals N IC 

The logbook values wwere not converted to 

Review of the specifirecommended. 

13 1/28/1986 Contaminated badge N IC 

The logbook values wwere not converted to 

of the specific proces

14 3/31/1986 Switched xtals N IC 

The logbook values wwere not converted to 

of the specific proces

15 3/31/1986 Reader error N IC 

Any 331 

Worker 

(Group 1) 

3/15/1986 

Further investigation revealed that a temporary employee had read these crystals. 

During normal processing, the technician moves the decimal on the meter two places to the right (divides by 100) before recording data. This converts from the nano couloumb reading on the meter to a mrem value on the sheets. It is our belief that the technician did not move the decimal in these cases. There is, however, no positive proof that this is what happened, so the dose of record will be left as it is entered in the computer from the data sheets. 

Not Applicable See Response 

This particular situatiwas not directly relata

data in this case were was discovered that a read the badges. Dosthat the nano coulomb by 100 in the conversthe record reflects the would result in an ovethus would be claimainteresting to note thaconduct a dosimetry iindividuals. 

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within the requirements of 42 CFR 82. 
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Table 5-2. Individuals with Documented Dosimetry Problems during the Period from March 1985 t

(selected from RFP 1986) 

Case 

Number Date Justification for Change 

Dose 

Investigation 

Report 

Consistency 

of Doses SC&A 

No dose information badge for the period w

individual was wearinwould not create a prowas eventually proce

16 3/15/1986 Badge not changed N See Response 

N indicates the logbook dose values did not agree with the hard copy dose values. Y indicates the logbook dose agreed exactly with the hard copy dose values. C indicates the logbook values were consistent with data in the hard copy record but did not exactly match. IC indicates the logbook values were either not provided or were greater than those in the hard copy record. These items require review 

data. 

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within the requirements of 42 CFR 82. 
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A review of Table 5-2 indicates that 8 out of the 17 entries related directly to issues with crystals. 

One entry indicated the crystal area was contaminated, two indicated bad crystals, two badges 

had switched crystals, and one had no crystals. One of the 17 entries stated that no badge was 

exchanged, and the remaining 8 were associated with reader problems or inconsistent readouts. 

The redundancy in crystals within a dosimeter, assuming only one crystal was compromised, 

does provide a mechanism for determining estimated doses from an alternate crystal. In cases 

involving absence of crystals, badge contamination, and reader errors, the redundancy of crystals 

in the badge may not provide a method for determining dose, and a dosimetry investigation 

would be expected based on current practices. 

5.2.2 External Dosimetry Investigations 

One method of reconciling lost, damaged, overexposed, or otherwise compromised dosimetry 

results with actual exposure in the field is to conduct an investigation of the potential exposure 

received by the individual. To evaluate whether dosimetry investigations were conducted, the 

relative threshold for these investigations, and the methodology utilized, SC&A conducted a 

preliminary evaluation of information for selected individuals in the 1985/1986 Dosimetry 

Problem Logbook, which are listed in Table 5-2 (RFP 1986). The evaluation sought to 

determine how, based on descriptions provided in the logbook, dose of record was assigned to 

these individuals. The doses in this logbook and the doses for the same period in the individual’s 

health physics file were also compared for consistency. SC&A also reviewed health physics 

files for any dosimetry investigations corresponding to the date listed in the logbook for the 

particular individual. 

SC&A found uncertainty existed in how or whether RFP external dosimetry investigations were 

conducted and documented. According to the NIOSH Evaluation of SC&A’s Draft Report on 

External Dosimetry Procedures, conversations with former radiological control staff indicate 

that occurrences meeting a specified threshold initiated external dosimetry investigations 

(NIOSH 2007e). While formal procedures were in place for dosimeter processing in 1983 and 

for external dosimetry investigations by 1997, the individual health physics files do not include 

documentation until the 1990s. SC&A had expected to be able to determine whether the 

assignment of doses to individuals in Table 5-2 was based on sound assumptions and methods 

and whether the derived dose for the investigation was consistent with the dose of record. The 

absence of records in the health physics files external dosimetry investigations for all 16 of the 

individuals evaluated made this difficult. In the case of the group listed, the only explanation is 

that provided in the logbook itself. The dosimetry logbook contained only dose values (if 

recorded) without any explanation of how they were derived. Field logbooks did not provide 

additional insight into the investigation process. 

The comparison of the doses in the logbook to those in the hard copy file posed some challenges. 

The hard copy file often listed a dose for the entire cycle (e.g., quarter) rather than the particular 

cycle of the dosimeter in question. The dose information for the cycle of, and the cycle 

immediately following, the dates listed in Table 5-2 was examined. In two cases, the logbook 

numbers agreed exactly with cycle data located in the hard copy record. In one case, the 

1985/1986 Dosimetry Problem Logbook entry was consistent with the results for the represented 
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quarter. In several instances, the dose values (e.g., cycle and quarter) in the health physics file 

were greater than those in the dosimetry logbook. Finally, for five individuals, the logbook did 

not provide the final dose value in mrem. This comparison would have been more effective if 

the data for specific badge cycles were available. No mechanism was available to enable a final 

determination of the legitimacy of the dose of record. 

NIOSH provided two examples of dosimetry investigations in NIOSH Evaluation of SC&A’s 

Draft Report on External Dosimetry Procedures (NIOSH 2007e). One investigation was for an 

individual receiving a high exposure over a biweekly cycle during 1964 (Doher 1964, Kittinger 

1964). The individual’s work activities and field radiation exposure rates were investigated at 

the request of a supervisor from the chemistry area. The second investigation provided was an 

investigation conducted as a result of 21 neutron films reported as “too dense to read” (Kirchner 

and Kittinger 1965). This investigation looked into the job descriptions and work locations of 

the 21 workers to determine if assigning an overall average dose was appropriate. The field 

radiological control organization was asked to investigate the most likely exposure received by 

these individuals. Furthermore, the memorandum indicated that when a neutron badge was “too 

dense to read,” the health physics organization in Buildings 771 and 776 should be notified. It is 

unknown whether this policy was formally implemented and if it included other areas of the site 

where neutron exposure was likely. It is also unclear if a similar process was implemented for 

beta/gamma dosimetry. 

SC&A acknowledges that examples of dosimetry investigations conducted prior to the 

formalization of the procedures were documented either in a formal letter to the file or on an 

investigation form. It is also true that both positive and zero values can be observed in the 

available investigations. During 1990 and 1991, hundreds of dosimetry investigations were 

requested of the field radiological control organization (RFP 1990a, RFP 1990b, RFP 1991). 

The primary concern regarding the completion of dosimetry investigations focuses on the 

operational period at RFP, particularly prior to the mid-1980s. In earlier years, documentation of 

dosimetry investigations is sparse. NIOSH has acknowledged that dosimetry investigations were 

not documented until a formalized procedure was put in place. The large number of 

investigations in 1990 and 1991, especially those related to unusual dosimetry results, and the 

significantly lower number of investigations located prior to this time indicate that the threshold 

for conducting a dosimetry investigation has changed over time. The relatively higher threshold 

for investigation in the early years suggests that unusual badge results (if evaluated under later 

criteria) may have gone uninvestigated. 

To date, NIOSH continues to indicate that RFP conducted dose investigations, but with minimal 

evidence that substantiates that these investigations actually occurred. However, there is no 

appropriate documentation of these investigations, at least regarding the data reviewed above. 

This issue has been difficult to resolve because of a lack of substantiation for either the NIOSH 

or worker comments. It is SC&A’s judgment that the NIOSH response has not adequately 

addressed the concerns expressed by workers over falsification or inadequacy of badge results. 

The NIOSH response is founded largely on statements by the former RFP radiological control 

staff, who had been directly involved in the dosimetry program, indicating that investigations 

were conducted, but the response does not provide further corroborative documentation. On the 
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other hand, RFP workers contend, both historically and during the course of the petition process, 

that their dose records are not consistent with their exposure experiences as they recollect them. 

To complicate matters, a former dosimetry technician recently indicated to SC&A that his 

supervisor doctored the numbers of highly exposed badges even after the three technicians had 

read the badge, as was the policy, and obtained similar results. According to this individual, the 

supervisor purposely lowered the dose of record (see Attachment 4). In addition, other 

individuals interviewed by SC&A who would have likely had involvement in investigations have 

indicated that they were not involved in either collecting data for or completing a dosimetry 

investigation (see Attachment 4). Neither NIOSH nor the RFP workers have put forth evidence 

that these dosimetry investigations were or were not conducted for lost, contaminated, or 

otherwise compromised badges. Insufficient evidence prior to the mid-1980s has been located to 

date explaining how the dose was assigned, making evaluation of the appropriateness of the 

method unfeasible. While a technical explanation may exist for badges reading zero in high dose 

rate situations, the NIOSH responses have not provided such an explanation. 

SC&A’s concern stems from the possibility of other reasons for these alleged discrepancies, 

reasons that bear on the data reliability question at hand. It is conceivable that doses were simply 

recorded as zero when there was an issue. For example, the Procedure for Assigning Dose to 

Dense Neutron Films indicates that at some time historically neutron badges with too much 

gamma resulted in the assignment of a neutron dose of zero (Kirchner and Kittinger 1965). A 

more appropriate way of calculating doses would be to perform an investigation into the 

individual’s exposures. Other portions of this section discuss additional examples of cases for 

which dosimetry investigations should have occurred. 

In the absence of investigation results, it is not possible to determine whether doses were 

adequately assigned when dosimeters or dosimeter components were lost, damage, overexposed, 

or otherwise compromised. The redundancy of crystals in the TLD would resolve some issues 

with lost or compromised crystals. In other cases, such as situations where there were no crystals 

or crystals were contaminated, this redundancy could not be used to assign dose. Furthermore, 

there was no redundancy in the film badges. To further complicate the evaluation, hard copy and 

electronic records do not always provide results for the particular processing run. Although at 

least one instance of a dosimetry investigation was located in a field logbook, the details of the 

investigation were not provided. 

5.2.3 Summary 

In conclusion, it is clearly evident that, whether investigations were conducted or not, they were 

not documented in the personnel radiation exposure files for the 16 individuals listed in 

Table 5-2. Doses assigned for available investigations contained positive, blank, or zero doses, 

indicating all dose assignments were not zero. Formal procedures for external dosimetry 

investigations have been located for 1997 and 1998, and requests for dosimetry investigations are 

available for 1990 and 1991. Investigations, particularly those located in individual health 

physics files, are sparse prior to 1990. Two of the 16 individuals had doses in their hard copy 

record that were identical to information provided in the dosimetry problems logbook, while 
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others appeared to have higher dose results in the logbook than in the hard copy record. 

Completing the review would require further investigation of the dosimetry processing log sheets 

for the particular badge cycle. SC&A only had informal assurances from RFP radiological 

control staff that dosimetry investigations were completed and questionnaires filled out. SC&A 

could find no documentation supporting the fact that these investigations were completed 

regularly prior to the mid-1980s and doses were assigned based on sound methodology. The 

existence of positive values would indicate that zeros were not the only doses assigned in 

instances where dosimeter problems were identified. This preliminary analysis indicates that 

staff did not appropriately document investigations and may not have conducted appropriate 

dosimetry investigations. In the end, the resulting data are not verifiable. 

For situations involving dosimeters that were compromised in one way or another, NIOSH 

contends that RFP conducted external dose reconstructions or investigations. As mentioned in 

Section 5.2, documentation of these dose reconstructions or investigations by RFP is lacking in 

many cases where dosimeter problems occurred. Based on the number of investigations 

conducted in 1990 and 1991 for unusual badge results, it is evident that the threshold for 

conducting external dosimetry investigations has changed over time, with the more stringent 

criteria occurring in later years. Because the criteria changed over time, it is likely that not all 

unusual dosimetry results were investigated for all periods of time. NIOSH located procedures 

for dosimetry investigations from 1997 and 1998, which demonstrate the implementation of a 

formal process. The investigation requests to field radiological control staff indicate that a 

method for dosimetry investigations was in place at this time. Prior to this, the predominant 

evidence presented by NIOSH is in the form of verbal statements made by former RFP 

radiological control staff as well as two examples of evaluations conducted in 1964 and 1965. 

5.3 LOGBOOK REVIEW 

Multiple workers have raised questions regarding the implications of entries of zero values and 

“no data available” in the actual dose records. Affidavits provided in support of the petition 

included discussions of situations where individuals received doses of zero or “no data available” 

when the field and work circumstances would indicate that external exposure was expected. In 

addition, petitioners raised the issue of incomplete dose records for workers and spoke of 

“falsified” dose entries and “manipulated dosimetry.” Throughout the SC&A review, petitioners 

and former workers repeatedly raised these issues. During interviews, petitioners and former 

workers indicated that field radiological control logbooks (e.g., contamination control logs, RPT 

logs, decontamination logbooks, and foreman’s logbooks) may substantiate the claims made by 

workers. According to field radiological control personnel, radiation monitors and their 

supervisors kept logbooks to record daily events, including contamination problems, incidents 

involving medical intervention or a trip to seek medical assistance, personnel contamination 

events, spills, records of special air sampling, radiation survey results, posting and downposting 

activities, respiratory protection posting activities, Selective Alpha Air Monitor (SAAM) alarm 

response and checks, tritium air sampling and survey data, and/or special whole body dosimetry 

results. The logbooks contained some information related to individual dose in some cases. 
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SC&A noted the lack of corroborating evidence to back up assertions made by both the 

petitioners and NIOSH’s site experts regarding the pervasiveness of dose record discrepancies 

and their historic origins. Under the broad guidance of the Advisory Board’s working group, 

SC&A decided to interview petitioners and other site experts directly on these issues and to 

conduct record reviews for such evidence at the Legacy Management’s Mountain View facility. 

SC&A conducted onsite interviews with the petitioners to clarify their concerns and ascertain the 

existence of supporting documents from March 27–29, 2006. SC&A requested records prior to 

the visit, and DOE’s Legacy Management personnel retrieved some of the records from the 

Denver Federal Records Center. 

Those records made available during the onsite visit included health physics progress reports, 

limited dosimetry processing data, information on tritium, and technical reports. SC&A 

reviewed the contents of approximately 26 boxes. The records that were not available during the 

site visit included the field radiological control logbooks. These were not retrieved in time for 

the onsite visit; however, they were made available shortly following the visit. Through the site 

visit, SC&A identified documents that might be helpful in evaluating the data integrity issues 

raised in the petition. As a result, additional searches of the record databases were conducted 

while on site and after the visit. The logbooks identified by SC&A and subsequently retrieved 

by Legacy Management included information for 1957–1996. The logbooks originally requested 

covered both the uranium and plutonium areas. 

 

At the April 12, 2006, working group meeting, SC&A provided a summary of the types of 

records reviewed during the visit to RFP. SC&A turned over the review of field radiological 

control logbooks and dosimetry information to NIOSH for completion, including those records 

retrieve originally for SC&A’s review (ABRWH 2006c). SC&A was asked to identify records 

that were not reviewed during the site visit and provide information on how these records can 

potentially answer data integrity issues. SC&A submitted Interim Evaluation of Data Reliability 

Issues: Needed Document Retrieval and Evaluation (SC&A 2006c), outlining specific data 

integrity issues, to NIOSH and the working group on April 19, 2006. This report contained 

recommendations for logbook and document reviews, including contamination control logbooks, 

foreman’s logs for the radiological control group, RPT logbooks, decontamination logbooks, 

special TLD results, and dosimeter processing information. SC&A continued to provide 

noteworthy information identified during searches to NIOSH during the course of the review, 

both formally and informally. NIOSH was to review the original set of logbooks requested by 

SC&A during the site visit for information pertinent to the SEC petition. The logbooks 

containing pertinent information, particularly individual dose data, were to be scanned and made 

available to the working group. The original intention was to pull logbooks and dosimetry 

information corresponding to the work location and period of concern for workers providing 

affidavits or expressing similar comments during the petition interviews. NIOSH was to review 

the logbooks for information on external exposures, overexposures, unusual exposure conditions, 

internal exposures, special dosimetry use, and involvement in incidents. The working group also 

asked NIOSH to retrieve urinalysis logbooks for comparison to the HIS-20 database to validate 

the reliability of bioassay records. 
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The NIOSH review was intended to track information provided by those submitting affidavits 

and during the petition interviews against that contained in the logbooks and dosimetry receipt 

and processing logs to validate the issues raised in the affidavit or comment. The various 

sources of dosimetry information were to be utilized to ascertain whether the logbooks 

mentioned the individuals identified as having concerns (primarily from the affidavits), and if 

any dose information differed from the dose of record. The health physics files were to be 

reviewed for documentation related to the years in question, including dosimetry investigations 

and reported dosimeter results. The dosimetry processing logbooks for the same time period 

were to be pulled to determine whether there was indication of dosimeter damage or a failure to 

return the dosimeter for the period in question. The secondary dosimetry results (e.g., chirpers, 

pocket ionization chambers), maintained in the field radiological control records or individual 

health physics files in some cases, were also requested to allow for evaluation of primary and 

secondary dosimetry results. The records search conducted by Legacy Management did not 

locate secondary dosimetry results. During many of the high-exposure jobs, secondary 

dosimetry was used to track real time dose. The ultimate goal was to compare documentary 

information from a variety of available sources and determine if there was, in fact, corroboration. 

The field radiological control logbooks did not always identify specific individuals providing 

affidavits or comments; therefore, the focus of the review was changed to verification of data for 

those individuals with internal or external monitoring information identified in the field 

radiological control logbooks. 

At the July 26, 2006, working group meeting, NIOSH provided a comparison between extracted 

exposure data from Logbook 12-12-66 to 12-31-68 (Kittinger 1966) and the individual health 

physics files. Information included dates of whole body counts, accidents/incidents, and 

exposures for a specified employee at a specified time. For each example, NIOSH checked the 

NOCTS database for information matching the employees mentioned in the logbook. A total of 

36 individuals selected from Logbook 12-12-66 to 12-31-68 (Kittinger 1966) were not claimants. 

If the employee was not a claimant, the radiation files for employees matching the names 

mentioned in the logbook were requested from DOE. For multiple hits (several radiation files of 

employees with the same last name), all possible matches were requested. NIOSH then 

evaluated the logbook data against the data in the health physics file, where available. 

Information in the logbook and health physics file was evaluated for exact matches if monitoring 

periods in both sources were identical and for agreement if the logbook cycle covered only a 

portion of the period identified in the health physics file (e.g., logbook information may cover 

one month while the health physics file lists only a quarterly value). Individual results evaluated 

were consistent between the logbook and the health physics files for those individuals reviewed. 

Although the health physics files for the 36 non-claimants were retrieved and are available on the 

O-drive, NIOSH evaluated only 19 of the 36 non-claimants. During the meeting, NIOSH was 

also asked to retrieve urinalysis logbooks for comparison to the HIS-20 database to validate the 

reliability of bioassay records. 

The working group raised the concern that the evaluation of Logbook 12-12-66 to 12-31-68 only 

covered the years 1966–1968 and was for individuals assigned to the plutonium areas. As an 

alternative to a sampling plan for time periods and facilities from 1969 through the 1990s 

(ABRWH 2006c, pp. 329–337), NIOSH provided Logbook Review for Rocky Flats (NIOSH 
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2006g), a review of RFP logbooks, for purposes of ascertaining data reliability and provided its 

results on the O-drive for working group review. NIOSH examined a total of 65 logbooks with 

43 containing individual data adequate enough to attempt a comparison. Two hundred ninety-six 

names were pulled from 33 logbooks, including 20 urinalysis processing logs. NIOSH covered 

nonplutonium areas for 1957–1960 and 1968, plutonium areas from 1964–1971, and urinalysis 

data from 1960, 1962, and 1964–1971. NIOSH indicated that in reviewing the logbooks to 

develop a sampling plan, data from after 1971 did not contain worthwhile information for 

database validation (ABWRH 2007). 

NIOSH stated in NIOSH’s Response to Logbook Report that SC&A was provided with an index 

of contents for 296 boxes (NIOSH 2007f). Attachment 12 is a compilation of results from all 

record searches conducted to date. As can be seen in Attachment 12, many of the search results 

were not relevant to the SEC petition evaluation review and were, therefore, not requested. It is 

important to recognize that a description of box contents does not equate to the review of box 

contents. 

 

SC&A conducted a review of the 59 logbooks including the 33 reviewed by NIOSH and 

compiled logbook entries potentially relevant to the SEC petition as a part of the review of data 

integrity issues subsequent to the original records request. These logbooks were focused on the 

1960s, particularly the 1969 fire, D&D, and included logbooks maintained by key field 

radiological control staff. The logbook entries of interest were extracted and are provided in 

three attachments. Attachment 14 contains logbook entries with individual-specific internal or 

external monitoring, references to special badging, and referrals to medical staff or the in-vivo 

counter. Attachment 15 represents logbook entries referencing radionuclides other than Pu-239, 

U-235, and U-238. Attachment 5 contains entries related to field measurements (e.g., surveys, 

air sampling), incidents, and destruction of badges. Entries were copied as they appeared in the 

logbook, including retention of abbreviations and misspellings, unless otherwise indicated. 

Some logbooks were difficult to read due to the poor handwriting and imaging. The reference to 

logbook pages means the page designated in the logbook (not to be confused with the pdf pages 

in the scanned version of the logbook). Names of individuals have been removed from the 

entries to comply with Privacy Act requirements. The following subsections describe the results 

of these investigations. 

5.3.1 Personnel Logbook Entries 

Entries linkable to particular individuals, including references to internal or external monitoring, 

special badging, and referrals to medical staff or the in-vivo counter were of particular interest in 

SC&A’s review. This information was compared with the data in the health physics file and the 

HIS-20 database to determine consistency between field logbook information and dosimetry 

data. This was particularly pertinent to the questions raised in the petition regarding blanks, 

zeros, or “no data available” entries in dosimetry records. NIOSH stated the following in 21 

March 2006 SC&A Comments and NIOSH Responses (NIOSH 2006h): 

Pre-1964: A blank indicates a period when the worker was not monitored. This 

situation will be dealt with by applying unmonitored dose using coworker data 
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(for radiation workers), or by applying ambient environmental dose (nonradiation workers). A zero indicates a monitored period when there was no 

positive recorded dose. This situation will be dealt with by applying missed dose. 

For the years 1964 and after, NIOSH stated the following: 

1964 and after: A blank or zero could indicate a period when a badge wasn’t 

returned at the scheduled badge exchange, but was rather retained by the worker 

for an additional badge exchange cycle. In this situation, all dose recorded on 

the badge was recorded in one badge exchange cycle, and a blank appeared in 

the record for the other exchange cycle. A zero entry in the dosimetry records 

could also indicate that there was no positive dose recorded on the badge. In any 

case, whenever a blank or zero appears in the dosimetry record, missed dose is 

assigned. 

“No data available” entries indicate instances when either the badge was not turned in at the 

scheduled badge exchange, or the badge was turned in but there was a problem with the 

dosimetry badge. NIOSH proposed to use missed dose, coworker dose, or ambient 

environmental dose when a blank or a zero appeared in the dosimetry record. The comparison 

between the individual monitoring data in the field logbooks and the dosimetry files served as a 

method for validating whether blanks, zeros, and “no data available” could be explained as 

described above. 

NIOSH was to provide a sampling plan for review by the working group that would encompass 

various years and facilities; however, NIOSH elected to directly implement its plan based on its 

own judgment of relevant logbooks. As a supplement to NIOSH’s investigation, SC&A 

conducted a preliminary screening to ascertain the usefulness of the logbook data in evaluating 

data completeness and accuracy. The goal of the screening was to identify individuals in the 

logbooks who also had both hard copy and electronic dosimetry results readily available for 

review. Approximately 70 claimants were mentioned in some capacity in the logbook. 

The field logbooks routinely refer to “special badging,” typically in the context of special 

dosimetry studies or job-specific usage. Special badging usually occurred with jobs with high 

exposure potential, such as the Zero Power Physics Reactor (ZPPR) project, work on the 

americium line, and special projects. In some cases, it was reported in the logbooks that routine 

dosimeters were worn in conjunction with the special dosimeters, while in other cases the special 

dosimeters replaced the routine dosimeters. For example, an entry from Logbook 12/5/66-

6/11/67 (RFP 1966a, p. 131) states, “Special film badges are to be worn by people involved with 

the PuBe Project. Regular film badges are not to be worn.” These badges were exchanged as 

frequently as daily (refer to Attachment 4), and a record of the exchange can be observed on the 

computer printouts in some claimant files. With a higher frequency of exchange, the badge 

results are more likely to be below the minimum detectable dose. It is also unclear how the 

dosimetry record reflected the special dosimeter results. 
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SC&A also observed in its review that special bioassay samples were not collected in all cases 

immediately following an incident (particularly minor incidents). Of the incidents reviewed, a 

majority of these were associated with wounds and skin contamination incidents. The medical 

record serves as an additional source of incident information that may or may not be reflected in 

the radiation exposure file. Although SC&A has identified dose data for individuals in a few of 

the logbooks reviewed, it has been unable to find information on the particular individuals 

submitting affidavits. 

5.3.2 Other Radionuclides 

The review gave rise to a concern about the exposure of personnel to radionuclides other than U235, U-238, and Pu-139. Thirteen of the 59 logbooks reviewed by SC&A mention operations 

involving secondary radionuclides including U-233, U-237, Pu-236, Pu-238, Am-241, Am-243, 

Np-237, Co-60, Cf-252, Ir-192, curium, thorium, and tritium. The 1966–1969 Special Analysis 

Logbook (RFP 1966b) contained individual-specific bioassay data for January 20, 1966, through 

January 13, 1969, for Sr-90, Po-210, Np-237, tritium, and thorium. Thorium, tritium, Po-210, 

Np-237, and curium were encountered at RFP for weapons-part handling and manufacturing. 

Other radionuclides such as Co-60, Cs-137, and Ir-192 were used for quality assurance testing. 

Some notable entries included a spill of neptunium and an inadvertent exposure to Co-60 

contamination. Inadvertent releases of tritium occurred, with a significant event in 1973 that 

resulted in a release to the environment as well as to the workplace. Thorium was mentioned in 

the context of thorium strikes and as ingots in Building 883. Clearly, the logbook entries 

indicate that numerous radionuclides were handled in some capacity at RFP. The entries also 

provided some information on the dates these radionuclides were handled. The logbooks 

demonstrated the potential for both internal and external exposure from radionuclides other than 

plutonium and uranium. Section 7.0 of this review evaluates exposure to other radionuclides in 

more depth. 

5.3.3 Field Logbooks, Incidents, and Badge Destruction 

Attachment 5 includes log entries related to incidents, field measurements, and badge destruction 

entries obtained from the 59 logbooks. This information pertained to concerns over processing 

of lost, stolen, or otherwise compromised dosimeters. The logbooks also contained periodic 

radiation and contamination measurements for high dose rate projects. Field survey information 

is useful in evaluating why badges may not have reflected the field exposure conditions and/or 

potential reasons for discrepancies between dosimeters and field exposure conditions. 

One particular concern raised in 11 different entries was the destruction of contaminated badges. 

Kittinger’s Personal Logbook 10/1/57–8/26/60 (Kittinger 1957) and RFP Logbook 5/10/66-

12/3/66 (RFP 1966c) included 11 references to the destruction of badges. Some of these were 

associated with specific individuals while others were more general comments. The following 

illustrates one example (Kittinger 1957, p. 13): 

Destroyed both exchange and permanent badges of [Name] [Badge Number], 

notified [Name] of security of intent. He asked for no formal notification of 
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destroyer. I asked guard [Name] to witness, which he did at 9:10 a.m. Badges 

were cut into small pieces and placed in the hot waste can.

Kittinger’s Personal Logbook 10/1/57–8/26/60 also indicated a general concern over the problem 

with contaminated badges (Kittinger 1957, p, 104): 

[Name] informed of the large number of badges that were found contam. He 

agreed to try to work toward a different badging system that would not require 

personnel to wear them in the area. He asked that [Name] be notified and his 

assistance enlisted to get Security to adopt a new system. I contacted [Name] 

with [Name] approval. [Name] is somewhat interested in the possibility of a film 

badge type substitution. 

Petitioners and former RFP workers have repeatedly mentioned in interviews that badges were 

destroyed. The entries in the logbook validate this claim, at least in earlier periods, when badges 

were contaminated. The frequency of badge destruction is unknown, yet contaminated badges 

appeared to be a significant enough problem that alternate badging systems were under 

consideration. Three RCTs interviewed by SC&A confirmed the policy of destroying 

contaminated badges. The dosimetry staff may or may not have been cognizant of the 

destruction of badges since this occurred in the field. Contaminated badges were not sent to the 

processing laboratory to prevent contamination of the laboratory and its instruments. SC&A 

found that further investigation into this practice is warranted, especially in the uranium areas 

where there was less containment of radioactive material. 

The logbooks also included statements regarding gamma alarm evaluations. One particular entry 

of interest was included in the Logbook W.D. Kittinger/R.M. Vogel 6-20-63 thru 10-27-67 

(Kittinger and Vogel 1963, p. 96), which stated the following:

Gamma alarm evac. At 2:00 PM. Good test. 72 people w/o film badges. 

The exact meaning of this entry is unknown, and it is unclear whether the 72 without film badges 

were supposed to be wearing them; however, this raises questions regarding the implementation 

of dosimetry requirements in the field. 

5.3.4 Field and Urinalysis Logbook Data Comparison 

To investigate the alleged lack of corroboration between dosimetry records and individual doses 

reported in the field logbooks, SC&A requested dosimetry processing logbooks/logsheets, 

individual dosimetry files, secondary dosimetry results, and field logbooks corresponding to the 

work location and time of workers expressing concerns. Information from these logbooks was to 

be used to confirm issues documented in the petition relating to the adequacy of dosimetry and 

the occurrence of incidents. 
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Historical data archived by the Denver Federal Records Center for the RFETS were reviewed by 

NIOSH and compared to radiological files and claimant files to determine the level of agreement 

between these data sources. The logbooks reviewed by NIOSH included the following: 

• Urinalysis/bioassay logbooks containing primarily or exclusively urinalysis or bioassay 

data 

• Health physics logbooks, specifically radiation monitor, contamination control, and 

health physics staff logbooks, containing some notes regarding bioassay data, wound 

counting, in-vivo counting, and external dosimetry data, as well as field radiological 

control conditions 

• Foreman logs, containing foreman’s notes for the day, shift notes, meeting notes, and 

occasionally individual-specific information such as a reassignment of duty, followup 

monitoring, or clearance for work; less helpful since they contained minimal individual 

data 

• Building logbooks, containing sampling results of floors, walls, equipment, and other 

surfaces or documenting radiological cleanup of the same 

 

NIOSH stated the following in its logbook evaluation report (NIOSH 2006g): 

Logbooks were requested from Mt. View RFETS Records staff starting in 

February 2006. Requests were made to Mt. View by the ORAU Team, and 

included search terms such as: urinalysis, bioassay, internal dosimetry, external 

dosimetry, and logbook. Occasionally, specific accession numbers of boxes 

containing logbook collections were identified and submitted to Mt. View. Dates 

were not necessarily specified at the start, to keep the search as broad as 

possible. Since April, Mt. View estimated that over 450 boxes were pulled from 

the FRC and that NIOSH and ORAU had reviewed over 1,000 documents. 

Requests were submitted through October, in attempts to find logbooks from all 

possible years. Logbooks of various types from 1957 through the mid-80s were 

located, including internal dosimetry logbooks from 1960 through 1971. 

The 65 logbooks reviewed by NIOSH primarily included logbooks requested by SC&A in later 

records requests. This compilation of logbooks was not intended to be representative of all areas 

and time periods, but was specifically chosen to obtain information on particular topics such as 

the 1969 fire, D&D, and logbooks for key field radiological control personnel. Based on the 

statements above from the logbook evaluation report, NIOSH indicated a total of 450 boxes of 

records, including logbooks extending into the mid-1980s, were retrieved from the Denver 

Federal Records Center. Information on which logbooks were retrieved from the Denver Federal 

Records Center was made available to SC&A February 13, 2007, by Legacy Management. 

These records sets contained logbooks as well as documentation relating to DAC-hour tracking, 

the external dosimetry program, the internal dosimetry program, the 1969 fire, and thorium. 

NIOSH selected the logbooks used in their comparison from among the 65 logbooks available on 
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the O-drive. In their response to SC&A’s draft logbook review (NIOSH 2007e), they indicated 

that additional logbooks were available, but were expected to contain minimal useful data. This 

determination was made based on their review of logbooks of the same type. The original list of 

logbooks requested by SC&A represented the years 1957–1996, and encompassed both 

plutonium and nonplutonium facilities. SC&A’s evaluation initially focused on 59 logbooks 

with a subsequent review of approximately 175 records sets including primarily logbooks. 

NIOSH conducted two discrete comparisons. The first comparison involved the Kittinger 

Logbook 12-12-66 to 12-31-68 (NIOSH 2006i). The Kittinger Logbook (Kittinger 1966) was 

maintained by a supervisor in charge of field radiological control activities and was particularly 

useful in identifying individual exposures or monitoring information within field logbooks. 

NIOSH extracted items of interest in the Kittinger Logbook 12-12-66 to 12-31-68, defined as any 

entry in the logbook that gave information of a specific nature that could be compared to 

information in an employee’s radiation file. For example, entries included dates of whole body 

counts, accidents/incidents, and exposures for a specified employee at a specified time. For 

several entries, the information identifying the employee was incomplete (e.g., only last name 

was given, some of which are very common). The working group raised the concern that this 

comparison covered only 1966–1968 and primarily individuals assigned to the plutonium areas 

and requested an expanded evaluation of logbooks for additional areas and years. The expanded 

logbook review by NIOSH examined a total of 65 logbooks with 43 containing individual data 

adequate enough to attempt a comparison. Names were pulled from 33 logbooks. 

In NIOSH’s analysis, values in health physics files were determined to either have exact matches 

(in agreement), to be consistent with logbook entries (either the dose record or logbook entry was 

not specific enough to determine an exact match), or to be inconsistent. The NIOSH evaluation 

reported the following (NIOSH 2006i): 

This evaluation found a 96% rate of agreement between data found in various 

logbooks, and the data found in the worker’s radiation files. We found no 

evidence of a systematic lack of corroboration between logbooks and the 

individual worker radiation files which would cast doubt on the integrity of Rocky 

Flats dosimetry data, nor was there any evidence of inappropriate manipulation 

of workers’ dosimetry results. 

NIOSH indicated the small numbers of confirmed mismatches were consistent with the types of 

clerical errors expected in a data set composed of hundreds of thousands of dosimetry results 

(NIOSH 2006i). 

SC&A was asked to perform a validation and analysis of the logbook comparisons conducted by 

NIOSH. SC&A reviewed the information for all the individuals (claimant and nonclaimant) 

identified and evaluated by NIOSH in both the Kittinger Logbook 12-12-66 to 12-31-68

comparison and the expanded logbook comparison, except for those whose health physics file 

was not available. Several logbook entries relating to smaller incidents, badge contamination 

and/or destruction, and exposure to other radionuclides were added to the SC&A evaluation as a 

means of investigating these particular topics. SC&A evaluated entries from a total of 33 
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logbooks for consistency with health physics files and HIS-20 or the equivalent, where data were 

available. The logbook entries were divided into those related to external exposures and those 

related to internal exposure. Individuals’ exposure identity numbers (EXPIDs) were identified 

using names and badge numbers. SC&A then used the EXPID to retrieve the results listed in 

electronic databases. A total of 31, 233, and 38 person-entries were evaluated for external 

exposure, urinalysis, and in-vivo counts, respectively. Comparison results were recorded as 

exact matches, consistent, inconsistent, and not available. In the case of urinalysis and in-vivo

counts, the date in the individual health physics file and the electronic database had to be within 

one week of that listed in the logbook. This was considered prudent because there may be a lag 

in time between a notation in the logbook and information provided in other sources. 

Percentages were calculated based on the total number of individuals evaluated for a particular 

area. 

SC&A first compared quantitative external dosimetry data to information in the health physics 

files. The smallest increment of time covering the period in question (e.g., quarterly, cycle) was 

used for comparison. Each 31 person-entries from the logbooks were compared to information 

from the RFP Coworker Stats (NDRP Included, HIS_20) file. The RFP Coworker Stats (NDRP 

Included, HIS_20) file contains electronic external dosimetry data and is the basis for the RFP 

external dosimetry coworker model. The file was not helpful in many cases since it primarily 

contained annual doses. Eleven of the 31 person-entries were compared to data from the hard 

copy NDRP data printouts in the health physics file. The remainder did not have NDRP data. 

SC&A compared bioassay data from the urinalysis logbooks to the results from the individual 

bioassay cards, the Health Sciences Data System (HSDS) printout, and the HIS-20 urinalysis 

data file, where available. SC&A reviewed the health physics files to determine if reports and/or 

monitoring data were available for in-vivo counts, wound counts, incidents, skin contaminations, 

dosimeter issues, and qualitative information. Tables 5-3, 5-4, and 5-5 provide a summary of 

these data validations. Individual entry comparisons are provided in Attachment 16. 

The individuals selected by NIOSH for comparison were primarily from the 20 urinalysis 

logbooks which included approximately 65% of the sample set. The urinalysis logbooks covered 

January 1, 1960, through May 11, 1971, and included gross alpha, electroplating, plutonium, and 

americium results. The field logbooks covered June 4, 1957, through August 24, 1971. 

Nineteen of the individuals from the Kittinger Logbook 12-12-66 to 12-31-68 evaluation were 

also evaluated in the expanded logbook review. 
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Table 5-3. Summary Results for Quantitative or Semiquantitative External Exposure Logboo

Number 

Description of Entry Number in Category 1 Comment Consistent or Exact 

Value Not 

Available in 

Comparison 

Source 

Exposure Values Recorded in Logbook vs. 

NDRP 11 

Original neutron and/or gamma data were compared to the dose values reported in the logbook. Where available, the specific period of time referenced in the logbook was used. 

10 0 

Exposure Values Recorded in Logbook vs. 

Coworker Stats 31 

Seven individuals were not listed in the coworker stats file. In three cases, the value in the field logbook exceeded that in the RFP 

Coworker Stats (NDRP Included, HIS_20) file.

21 7 

Exposure Values Recorded in Logbook vs. 

Health Physics File 

31 

There were six situations where exact matches were found. This corresponded to situations 

where the logbook provided either the dose for the year or for the quarter. When the dose did not match, there may have been an issue with inadvertent exposure of the badge to neutrons. No investigations were identified in the individuals’ health physics files to confirm this. 

30 0 

Extremity Dose 1 Annual dose was greater than the dose through the date of logbook entry. 1 0 

Overexposure Notation 5 Exposures for the monitoring period were in excess of DOE exposure limits. 5 0 

The same individual may fall into more than one category. 

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Table 5-4. Summary Results for Qualitative External Exposure Logbook Analysis 

Number 

Description of Entry Number in Category Comment Consistent or Exact No. with Dosimetry Investigations 

Overexposed or 

Contaminated Film 3 There was no indication of investigations regarding how dose was eventually assigned. 0 3 

Dose Adjustments 3 There was no indication of dose adjustments in the health physics file. 0 3 

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Table 5-5. Summary Results for Internal Monitoring/Exposure Logbook Analysis 

Numbe

Description of Entry No. in Category Comment Consistent or Exact Inconclu

In-vivo Results Recorded in the Logbook vs. the 

Health Physics Record 37 

The inconclusive entries were due to the unavailability of the health physics file with one exception. The 

incident file for one individual indicated that he was recommended for an in-vivo count; however, there was no evidence that this occurred. 

32 4 

Wound Contamination/ Monitoring 6 All health physics files evaluated had documentation of a wound count for the data in question. 6 0 

Incident Involvement 

12 

SC&A chose three additional incidents beyond those selected by NIOSH. These incidents involved a fire 

and a spill. No followup bioassay was completed following these incidents. 

9 0 

Skin Contamination Events 7 All health physics files evaluated had documentation on a skin contamination event. 7 0 Bioassay Results Recorded in the Logbook 

vs. the Health Physics Record 

233 

No health physics files were available for eight personentries; therefore, these were considered inconclusive. 

The four individuals with inconsistent results had numerical differences between what was listed in the logbook and the health physics file. 

220 8 

Bioassay Results Recorded in the Logbook 

vs. HIS-20 Results 233 

The inconclusive entries were primarily the result of the absence of data in the HIS-20 urinalysis file. The 

two individuals with inconsistent results had numerical differences between what was listed in the logbook and HIS-20 urinalysis results. 

133 98 

Other Radionuclide Monitoring 

2 

According to logbook entries, the two individuals were involved in operations with a potential for thorium 

exposure. SC&A evaluated health physics records for availability of gross alpha and/or thorium analysis. An electroplating result followed within one week of the logbook entry. 

0 2 

Urinalysis Requested 

2 

Where the field logbook indicated a urine sample was requested, a urine result was found in the general time 

period. 

2 0 

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There were 31 entries with quantitative or semiquantitative external dosimetry results. All but 

one entry was consistent with the value in the health physics file. Consistency was defined as an 

exact match or a logbook result that was less than the quarterly dose for the quarter 

encompassing the badge cycle. In some cases, only the annual dose was available. Where 

possible, SC&A used the cycle data for comparison. SC&A compared field logbook values with 

data in the RFP Coworker Stats (NDRP Included, HIS_20) file for the 31 person-entries. Dose 

values were inconsistent in only a single instance. The coworker dose file did not include 23% 

of the 31 individuals. NDRP data were available for 11 of the 31 individuals. SC&A compared 

the original gamma and neutron doses on the NDRP printouts to the logbook values for these 11 

individuals and found inconsistency in only one instance. Five instances of overexposure 

notations were examined. Exposures for all five for the monitoring period exceeded the DOE 

exposure limits. Two instances of contaminated badges were identified; however, the health 

physics file did not contain a dosimetry investigation. Three instances of dose adjustments were 

noted in the field logbooks; however, SC&A did not locate documentation regarding these 

particular adjustments in the health physics file. 

Overall, the urinalysis data in the logbooks (field and urinalysis) and the health physics file are 

comparable. Approximately 94% of the results agree. In eight cases, health physics files were 

not available. Four individuals had numerical differences between the logbook and the health 

physics file. Bioassay results were also compared to the values in the HIS-20 database. SC&A 

found that 58% of the bioassay results from the urinalysis and field logbooks agreed with data in 

the HIS-20 database. The remaining 42% were absent from the HIS-20 database. These include 

both plutonium and uranium results, with some representing what SC&A believes are significant 

bioassay results. 

The analysis for in-vivo results was qualitative as specific results were generally not listed in the 

logbook. If there was an in-vivo count documented within one week of the date mentioned in the 

logbook, the two sources were considered consistent. SC&A found that 86% of the logbook 

entries were consistent with the information found in health physics files. One individual did not 

have an in-vivo count in his health physics file even though he was referred for an in-vivo count. 

In four instances, the health physics file was unavailable. Six out of six individuals had wound 

count information in the health physics files for the dates mentioned in the field logbooks. Seven 

out of seven individual had skin contamination reports in the health physics file for the dates 

mentioned in the field logbooks. In the case of incidents, those individuals chosen by NIOSH 

who had incidents noted in the logbooks all had incident reports in their health physics files. 

Only one of the three additional individuals selected by SC&A had a report related to the 

incident in the health physics file. In the three cases where an incident report was not available, 

bioassay immediately (i.e., within one week) following the event was also not available. 

In NIOSH’s Response to Logbook Report (NIOSH 2007f), NIOSH conducted its own review of 

agreement between the logbooks and the HIS-20 database. The results of its analysis indicated 

90% agreement for external exposure, 86% for in-vivo counts, and 92% for urinalysis. At first 

glance, there seems to be disparity between the results obtained by SC&A and NIOSH. 

However, SC&A and NIOSH used different methodologies to compare HIS-20 data with field 

logbook data. SC&A chose to compare all entries (31, 233, and 38 person-entries for external 
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exposure, urinalysis, and in-vivo counts, respectively) originally selected by NIOSH as well as a 

few added by SC&A against data in the HIS-20 database. Individuals not in the HIS-20 database 

were included in the calculation of percentage agreement. For example, SC&A evaluated 233 

bioassay person-entries against the HIS-20 database. SC&A also went back to the logbooks and 

included results recorded as background or a percentage of the maximum permissible limit 

(MPL) that can be converted to a bioassay concentration. Of these, 133 entries were consistent 

between the field or urinalysis logbooks and HIS-20, constituting 58% agreement. Qualitative 

analyses were considered separately. The NIOSH review only included those logbook entries 

with quantitative bioassay results where data were available in HIS-20. This represented 122 

individuals. The 92% matching rate reported in Table 2 of NIOSH’s Response to Logbook 

Report (NIOSH 2007f) did not include an analysis for the remaining urinalysis entries originally 

identified by NIOSH. This difference in methodologies accounts for the seemingly large 

differences in percentage of matching results between SC&A’s evaluation and that of NIOSH. 

Special Bioassay Analysis 

The 1966–1969 Special Analysis Logbook (RFP 1966b) included bioassay results for Sr-90, Po210, Np-237, tritium, and thorium. The NIOSH review indicated the following (NIOSH 2006g): 

Eight cases from the 1966–1969 Special Analysis Logbook did not have matching 

information in the radiological files. Six of the eight had results of zero for the 

analyte of interest. 

NIOSH indicated in its analysis that only 16 out of 24 individuals had bioassay data for tritium, 

polonium, strontium, neptunium, and thorium. The agreement of only 67% of dosimetry data 

with urinalysis data in the 1966–1969 Special Analysis Logbooks indicates a significant gap 

exists in the health physics files concerning monitoring of other radionuclides (e.g., thorium, 

tritium, curium, and neptunium). 

Data from the field logbooks referencing individuals working with or around radionuclides other 

than plutonium, americium, and uranium were identified; however, only two individuals had 

health physics files available. Both individuals were potentially exposed to thorium in 1960. No 

thorium or gross alpha bioassay data were available; however, electroplating data were available 

one week after the date of reference in the logbook. Falk (2004) indicated in the internal TBD 

that site information about possible interferences with this method is not available. The absence 

of gross alpha and radionuclide-specific data to determine internal exposure from thorium, 

polonium, neptunium, and other transuranics may prevent assessment of internal dose for these 

radionuclides. An alternative method would be to assume the bioassay value was equivalent to 

the plutonium values. Technical Basis for Rocky Flats Plant—Occupational Internal Dose (Falk 

2004) stated the following: 

Interferences were likely in the period 1952 through 1962 because of a lack of 

specificity of the chemical procedure to isolate only the plutonium in the extract. 

Plutonium results would include some americium and thorium activity. 
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It also stated the following: 

From 1963 to 1977, the ion exchange method significantly reduced interferences 

from americium, uranium, and thorium. As the PHA system was phased in 

starting in 1973, the possibility of interferences was further reduced. After 1977, 

these interferences were not a significant issue for plutonium urine results 

because all samples were counted on the PHA system. 

The radiochemistry for plutonium allowed only some of the thorium and americium to come 

through. The analyses that would contain thorium and americium were limited primarily to the 

pre-1963 time period. If thorium was the predominate radionuclide of concern, as was the case 

with the U-233 processing, use of plutonium bioassay results may underestimate thorium 

uptakes. Interferences by polonium, neptunium, and other transuranics were not specifically 

addressed in documentation reviewed to date. The techniques used for determining internal 

exposure to alpha emitters would not be useful in determining uptakes of Sr-90. The absence of 

gross beta or radionuclide-specific data creates a bioassay gap for those exposed to Sr-90. In 

general, tritium bioassay data is well documented on bioassay cards in health physics files 

starting in the early 1970s. Prior to this, the tritium bioassay data are sparse. Although the 

bioassay cards in the late 1960s had thorium as an analysis type, no thorium bioassay results 

were observed in the approximately 150 individual files examined. 

SC&A March 2007 Logbook Review 

After reviewing the results of NIOSH’s logbook review, SC&A expressed some concern that 

NIOSH’s review may not have captured the full range of activities and time periods of interest to 

the working group. In response, NIOSH stated the following (NIOSH 2007e): 

While there are additional logbooks available from Mountain View, these 

additional logbooks are expected to contain minimal useful data, based on our 

review of other logbooks of the same type (e.g., contamination control, foreman, 

etc). The amount of time required to scan and review them is not justified given 

our results to date. 

Furthermore, it stated the following (NIOSH 2007e): 

Bioassay logbooks which do contain data that may be traced, were phased out 

through 1971 as data were electronically recorded. 

NIOSH indicated that a total of 450 boxes had been retrieved from the Denver Federal Records 

Center (NIOSH 2006g). The working group, with concurrence from NIOSH, asked SC&A to 

conduct a sampling of records not previously reviewed among the 450 records sets NIOSH 

referred to in its logbook evaluation report (NIOSH 2006g). This sampling was to focus on 

those periods of time and facilities that would afford a more representative sampling of available 

logbooks and related documents. Data sources from both the NIOSH and SC&A records 

searches were reviewed to identify additional logbooks for areas and time periods without 
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adequate coverage among the 450 records sets. The objective was to determine if specific 

relevant entries or data could be identified in these logs and to what extent these various 

categories of logs were rich enough in individual specific data to represent a means of database 

validation. 

 

SC&A requested that RFP provide a list of the bar code numbers (or records sets) pulled by both 

NIOSH and SC&A since the initial records search. Attachment 17 lists records retrieved from 

the Denver Federal Records Center for review during the March 12–16, 2007, onsite visit. The 

attachment includes unique identifiers, description of the contents, and comments pertaining to 

the availability of individual specific monitoring data. SC&A reviewed the information and 

selected records concentrating on the period 1970–1995 and covering Buildings 371, 431, 444, 

559, 561, 707, 750, 771, 776, 777, 778, 779, 881, 883, and 886 and the pond areas. SC&A 

focused primarily on retrieving the following record types: 

• Urinalysis logbooks 

• Dosimetry processing logsheets 

• Radiological control logbooks (i.e., RPT logs, contamination control logs, radiological 

control foreman’s logs, field radiological control supervisor logs, decontamination 

facility logs) 

Records sets previously reviewed by SC&A were excluded. Safety concerns and individual 

radiation exposure files were also excluded for this review. 

During the period of March 12–16, 2007, Joe Fitzgerald and Kathryn Robertson-DeMers of 

SC&A reviewed these records at the Legacy Management offices in Westminster, Colorado. 

SC&A reviewed ~175 records sets in hard copy or on microfilm. A box or roll of film often had 

multiple bar code or receipt numbers in its contents. Data sets were examined to determine if 

they included individual-specific data. Many of the records collected required review for 

classification prior to release to SC&A. Attachment 17 includes a more detailed description of 

the information found under each bar code or receipt number as well as a notation of whether the 

records set contained individual monitoring information. Foreman’s and contamination control 

logs contained only minimal references to individual monitoring data interspersed throughout the 

logbook. Radiological control supervisor and RPT logbooks contained more information on 

individuals, particularly if there was an incident, personnel decontamination, or wound count (in 

the field or by medical staff). Many of the records sets described as radiation monitoring survey 

logbooks contained radiation and contamination survey data, instrument performance or check 

logs, and special air sampling logs. This information was not directly applicable to individual 

dose reconstruction. 
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SC&A identified several records sets that contained urinalysis results or dosimetry processing 

data. Those not currently available on the O-drive included the following: 

• “Hotman” logs with individual urine, blood, and fecal analysis information 

• Wound count data 

• Americium urinalysis data 

• Tritium bioassay data 

• Radiation dosimetry badge data by month or quarter 

• Special TLD dose measurement information 

• Transuranic registry information for individuals 

• External dose distribution data 

• Gamma-neutron ratios by department for 1981 

• Dose rate for various aged and/or shielded material 

• Gamma energy distribution data 

The records reviewed contained useful data for database validation. A set of 27 entries were 

selected from bioassay logbooks collected during the visit. Those individuals chosen were not 

included in previous analyses completed by SC&A. The focus of this review was to compare 

selected logbook entries with results in the HIS-20 database. Results are presented in 

Attachment 16, Table 16-7. Both fecal and urine samples were included in the analyses. There 

was information available on blood assay; however, there was no data for blood in HIS-20. Ten 

of the 27 entries showed consistency between the logbook and the HIS-20 value. One logbook 

entry did not match the HIS-20 value. Over 50% did not have data in HIS-20 for the date in 

question and in some cases there was no data at all in HIS-20. Many of entries absent from HIS20 were fecal samples taken from a series of logbooks containing individuals involved in 

significant incidents or the “Hotman” logbooks. 

While NIOSH indicated that post-1971 logbooks were not “data rich” (NIOSH 2007f), SC&A 

has found, in its limited sampling, a number of relevant logbooks containing useful data beyond 

that year in the 1970s, 1980s, and 1990s. However, while these entries include individual 

identified external and internal exposure measurements for a broad range of facilities and time 

periods, which are relevant to data validation, this new information would not change the 

conclusions reached in the previous logbook reviews.

Conclusion 

In summary, the following conclusions can be drawn from the comparison of logbook 

information with health physics file data and HIS-20 data: 

(1) SC&A found individual-specific monitoring information in both field radiological control 

and urinalysis logbooks. This data included dosimetry data for specific projects and 

cycles, urinalysis data, incident involvement, and references to wound and in-vivo counts 

that could be compared to health physics files and the HIS-20 database for validation of 

bioassay and dosimeter results. The logbook entries validated petition statements related 

to frequent fires and incidents as well as the existence of high radiation areas. There 
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were entries mentioning special projects involving radionuclides such as Po-210, U-233, 

U-237, Pu-236, Pu-238, Am-241, Am-243, Np-237, Co-60, Cf-252, Ir-192, curium, 

thorium, and tritium. There were 11 entries related to the destruction of badges providing 

additional examples of situations for which external exposure investigations should have 

been conducted. 

The period of interest for the logbook review discussed at the July 26, 2006, working group 

meeting (ABRWH 2006c), included both plutonium and nonplutonium areas for the period from 

1969–1990. NIOSH covered nonplutonium areas for 1957–1960 and 1968, plutonium areas 

from 1964–1971, and urinalysis data from 1960, 1962, and 1964–1971. NIOSH indicated that in 

reviewing the logbooks to develop a sampling plan, data from after 1971 did not contain 

worthwhile information for database validation (ABWRH 2007). 

(2) During a review of logbooks on March 12–16, 2007, SC&A identified a select set of 

records that were relevant for database validation, including individual identified external 

and internal exposure measurements for a broad range of facilities and time periods (with 

relevant entries beyond 1971). 

(3) The methodology applied by NIOSH and SC&A to determine the percentage of matching 

or consistent values between HIS-20 and logbook entries led to a disparity in results. 

NIOSH selected only those individuals with quantitative data. The percentages were 

based only on the individuals in HIS-20. SC&A used a more conservative methodology 

that included all individuals with semiquantitative and quantitative results in the 

comparison without regard for whether they had data in HIS-20. NIOSH’s analysis 

compared field and urinalysis logbook information for all individuals originally identified 

by NIOSH to results in HIS-20. Matches for individuals who had no data in HIS-20 were 

determined to be inconclusive. For example, NIOSH based its percentage on 122 

individuals for urinalysis, whereas SC&A based its percentages on 233 individuals. 

(4) SC&A found that 96% of the external dosimetry data from 31 individuals had consistent 

data between the field logbooks and the corresponding health physics file. Of the 31 

individuals, 23% were not found in the HIS-20 database and therefore were labeled 

inconclusive. 

(5) SC&A found that 94% of the bioassay results from the urinalysis and field logbooks 

agreed with the individual bioassay cards in dosimetry records. Eight were considered 

inconclusive because the health physics files were not available for comparison. 

(6) SC&A found that 58% of the bioassay results from the urinalysis and field logbooks 

agreed with data in the HIS-20 database. The remaining 42% were absent from the HIS20 database. These include both plutonium and uranium results, with some representing 

what SC&A believes are significant bioassay results. An additional comparison of 

entries from logbooks reviewed in March 2007 indicates that > 50% of the entries were 

not represented in HIS-20 including positive results. 
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(7) SC&A found that 86% of the entries indicating in-vivo counts in the field logbooks had 

corresponding in-vivo counts in the individual health physics files. The health physics 

files were unavailable for four individuals. 

(8) NIOSH’s finding of agreement of only 67% of dosimetry data with urinalysis data in the 

1966–1969 Special Analysis Logbooks indicates a significant gap exists in the health 

physics files concerning monitoring other radionuclides (e.g., thorium, tritium, curium, 

and neptunium). NIOSH did not provide the names corresponding to those evaluated 

from this logbook to SC&A or the working group for validation. 

(9) Entries from logbooks validate the destruction of contaminated badges for at least some 

cases in the 1950s and 1960s. 

(10) The medical record serves as an additional source of incident information that may or 

may not be reflected in the radiation exposure file. 

Logbook entries and internal and external data within the Health Physics records gave no 

indication of systemic discrepancies where DOE records were available for comparison. 

However, as previously noted, the logbooks selected by NIOSH did not include entries from 

1972–1990 and were heavily weighted towards the plutonium areas. The evaluation by SC&A 

indicated that health physics files were incomplete relating to dosimetry investigations, bioassay 

for other radionuclides, and incident reports. Significant gaps were identified in HIS-20 external 

dosimetry and urinalysis data, including positive results. The evaluation also found that the 

health physics files were incomplete as they relate to dosimetry investigations, bioassay for other 

radionuclides, and incident reports. The logbook review yielded minimal information pertaining 

to discrepancies between field exposure conditions and dosimetry readings raised in the petition. 

5.4 DESTRUCTION OF RECORDS 

Destruction of records was raised in the petition and again at the Denver Advisory Board 

meeting. In particular, a former worker shared his concerns related to records disposed of at the 

onsite landfill. NIOSH summarized the concern as follows (Baker 2006): 

A concern was raised during the Denver Advisory Board Meeting by a former 

RFP worker who mentioned that records from an onsite RFP trailer T-690 had 

been sent to the landfill in the 1989–1991 timeframe. The records allegedly 

included survey reports and personal radiation exposure files, and appeared to be 

original records. The records appeared to the worker to have come from areas 

all over the plant. This trailer housed the Progression Committee and Radiation 

Operations, including exempt and nonexempt personnel. Allegedly, during a 

General Accounting Office (GAO) audit, the records were brought to the trailer 

for temporary storage. The RCTs started to look into these boxes. Three to four 

weeks later following completion of the GAO audit and upon return to the trailer 

on a Monday, the worker found the boxes missing. Three to four days later, a 

truck driver was delivering water to the trailer, and an RCT present asked him if 
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he knew what had happened to the records. The truck driver indicated that he 

was called in on the prior Sunday and asked to load the records and dump them 

in the landfill. Descriptions of the boxes’ contents are based solely on the former 

worker’s account. 

NIOSH investigated the concern in an attempt to determine whether this event occurred and the 

types of records that may have been involved. It also examined the situation in the context of 

establishing a capability to perform dose reconstruction. NIOSH contacted and interviewed 32 

former RFP workers, including individuals who had an office or worked in the T690 trailer, and 

former radiological control personnel. None of the individuals provided information on the exact 

contents of the boxes; however, a number of individuals believed that the boxes contained 

contamination and area survey records, dose reports, and possibly air sampling data from various 

production buildings. NIOSH concluded the following (Baker 2006): 

In summary, it can’t be conclusively determined from the discussions that any 

original Individual Radiation Exposure History Files or individual exposure 

information that should have been contained in those files were included in the 

boxes of records removed from the T690 trailers. However, the discussions did 

not identify any specific individual radiation exposure records observed in the 

boxes and the one medical record that was identified as being in the boxes was 

located in the Records Repository at the Denver Federal Center. Discussions 

also indicated the radiation exposure information in the boxes might have been 

the non-record Quarterly High-to-Low Dose Reports sent to management and 

radiation protection staff. 

The investigation was inconclusive with respect to whether this was an isolated incident of 

alleged records destruction at RFP. What is known in relation to RFP’s records retention is 

limited; however, the information described below was available from the documentation. 

A memorandum from R.M. Vogel to J.R. Mann (Vogel 1969) made recommendations not to 

read film in nonplutonium areas outside of the health physics, nuclear safety, uranium chemistry, 

production control and quality groups. Furthermore, the memorandum recommended discarding 

the film after several weeks: 

Should this recommendation be adopted it would necessarily be limited to persons 

not working in the plutonium areas and would result in a reduction in the film 

processing workload by at least 1000 packets per quarter. The undeveloped film 

should be retained for a short time (several weeks) after the regular film badge 

change before it is discarded. 

Dosimetry data linkable to an individual, especially in the case where they represent the only 

record, have a records retention period of 75 years. The discarding of this film appears to be 

contrary to these requirements. In order to verify whether the film was destroyed, SC&A asked 

Legacy Management to search for beta/gamma dosimeter film. Film was available for 1953–

1970 at the St. Louis Federal Records Center; however, it was not organized by building so it is 
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Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

difficult to determine from the search results whether the film mentioned above was included. 

Verification would require retrieval of film from St. Louis and a subsequent review, which was 

not feasible given the time constraints. 

In conclusion, the particular records destruction example presented by the former RFP worker 

was inconclusive; however, other documentation indicated that there was a recommendation to 

discard dosimeter film from individuals outside the plutonium areas. Further investigation into 

whether this did, in fact, occur should be considered as this film was the only legitimate source 

of dose information for these individuals. Dosimetry processing sheets merely indicate the 

badges were not read. 

5.5 RESPONSE TO DATA INTEGRITY EXAMPLES ANALYSIS 

5.5.1 Background 

On August 25, 2006, NIOSH provided the Advisory Board working group with Data Integrity 

Samples Analysis 08-25-06 (NIOSH 2006j), an evaluation of the relevance and possible 

implications of a number of individual concerns expressed by the petitioners and members of the 

public. In this document, NIOSH examined “whether or not the described situations or 

circumstances impair NIOSH’s ability to conduct dose reconstruction of sufficient accuracy” 

(NIOSH 2006j). The NIOSH review focused on the integrity of the data used for dose 

reconstruction (external dosimetry and bioassay results) and whether dose reconstruction could 

be performed with sufficient accuracy. Some of the individuals included had completed dose 

reconstructions. Other examples are from individuals who are not claimants. A total of 41 

examples were evaluated, with some containing multiple elements. The examples included 

concerns or comments from the following sources: 

• Affidavits within the SEC petition 

• Advisory Board public comment meetings on April 26, 2006, and April 27, 2006 

(ABRWH 2006g, ABRWH 2006h) 

• Rocky Flats Citizens Advisory Board work session on May 17, 2001 (RFCAB 2001) 

• Advisory Board working group meetings 

• Discussions with petitioners 

The analysis included individual-specific information as well as general concerns. Multiple 

individuals submitted comments concerning badges that did not reflect field conditions, the 

occurrence of black badges and subsequent assignment of zero dose, dosimetry processing and 

recording practices, incidents and their linkage to internal exposure, exposure geometry and 

partial body exposure, high-fired oxide exposures, and records destruction. During the August 

31, 2006, working group meeting, NIOSH indicated that the SEC petition evaluation report 

included generic answers to questions that arose in the petition affidavits (ABRWH 2006e, 
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pp. 290–291). The Data Integrity Samples Analysis 08-25-06 report (NIOSH 2006j) prepared by 

NIOSH was concerned primarily with evaluating the 41 examples at an individual level. Where 

examples were individual specific, NIOSH reviewed the individual radiation exposure files and 

made conclusions based on this information (ABRWH 2006e, pp. 317–323) to further 

substantiate information provided in the SEC petition evaluation report. These individual 

examples were used to demonstrate that dose reconstruction was feasible. 

The working group asked SC&A to review the Data Integrity Samples Analysis 08-25-06 report. 

When assessing this report, SC&A focused on discerning discrepancies in data that are systemic 

to RFP recordkeeping. The exercise was not interpreted as a review of isolated cases on a 

worker-by-worker basis. Examples were used in some cases to demonstrate potential difficulties 

associated with the reconstruction of dose. SC&A reviewed each of the 41 examples in its 

original context. During this review process, SC&A identified five concerns that were not 

originally evaluated by NIOSH but are issues that have arisen in the main portion of the petition 

and/or during working group meetings. These additional examples dealt with unauthorized 

practices related to dosimeters and completeness of records. In their February 28, 2007, 

response to SC&A draft data integrity example review, NIOSH provided comments on the 

additional five concerns (NIOSH 2007f). SC&A had concerns regarding the abbreviated or 

incomplete descriptions of the issues by NIOSH. As such, SC&A based its responses on the 

original documentation of the concern and not the NIOSH description provided in Data Integrity 

Samples Analysis 08-25-06.

Some concerns fell outside the purview of EEOICPA Subpart C but were applicable to 

Subpart E. These were related to chemical exposure or the synergism between radiation and 

chemical exposure. The synergistic effects of exposure to chemical and radiological hazards are 

not encompassed by SEC regulations (although addressed in research considerations under 

EEOICPA). Chemical and mixed exposures are considered directly under Subpart E of the 

EEOICPA. These concerns should be directed to the DOL under the provisions of Subpart E. 

Several examples provided information on the internal and external dosimetry program and 

major incidents. In some cases, no particular concern was defined in the example and a response 

was not required. 

The NIOSH responses to concerns raised in the petition and in other sources were discussed at 

the August 31, 2006, working group meeting (ABRWH 2006e). The working group requested 

that SC&A evaluate Data Integrity Samples Analysis 08-25-06. In making its evaluation, SC&A 

examined whether the NIOSH responses to data integrity examples described situations or 

circumstances that may impair NIOSH’s ability to conduct dose reconstructions and if data used 

in dose reconstruction would be adequate and complete. SC&A evaluated each of the responses 

provided by NIOSH regarding the applicability of the concern to the ability to perform dose 

reconstruction, as documented in Attachment 18. This attachment provides the NIOSH summary 

of the affidavit or other worker comments, the complete NIOSH evaluation (except where 

specifically noted), and the SC&A response to this evaluation. The responses provided by 

SC&A are not limited to the individual, but consider the broader implications of the comments. 

SC&A did not restrict comments exclusively to data integrity, but included comments related to 

other findings in this report. The topics raised by the commenters covered a diverse set of issues. 
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Some of the examples provided describe situations with worker safety implications and are 

therefore of significant importance; however, SC&A evaluated them only in the context of 

whether or not NIOSH can conduct sufficiently reliable and accurate dose reconstructions. For 

each example, SC&A either concurred with the NIOSH response, concurred with a qualifying 

statement, determined the NIOSH response was incomplete, determined the comment and/or 

NIOSH response was inconclusive, identified information only comments, or indicated that the 

NIOSH response was inadequate. NIOSH’s August 25, 2006, report included a total of 41 

examples, which were often subdivided into separate concerns (NIOSH 2006j). SC&A 

concluded the following: 

• Concurrence (57) 

• Concurrence with a qualified (11) 

• Inconclusive (27) 

• NIOSH response is incomplete (9) 

• An adequate response has not been provided (14) 

• No issue defined in the affidavit requiring response (7) 

The above statistics included the five additional concerns identified by SC&A during their 

review. 

5.5.2 Badge Results Not Reflective of Field Exposure Conditions 

A number of safety concerns were raised by RFP workers, including elevated backgrounds in 

dosimeter storage areas, the pulling of dosimetry as a result of an RWP violation without a 

concurrent restriction on work, and a dosimeter assembled without TLD crystals. Several of 

these situations should have resulted in a dosimetry investigation. Investigation reports were 

located for those situations corresponding to the late 1990s as procedures for dosimetry 

investigations were available. NIOSH has provided a response to the petition comments, public 

comments, and safety concerns (refer to Section 5.1). The purpose of the analysis below is to 

demonstrate the magnitude of concerns expressed by workers over the accuracy of the external 

dosimetry program and the lack of corroborative resolution of these issues to date. 

The agreement of film badge results with the corresponding field exposure conditions has been 

questioned in the petition, highlighted in a number of historical safety concerns, and cited in site 

expert interviews. Petitioners have provided examples of conditions where individuals were 

working in a high radiation area for a period of time long enough to receive in excess of the 

minimum detectable dose, but the individuals had little or no dose recorded. Fifteen individuals 

who provided comments either in the petition or during public comment periods brought up 

concerns regarding the accuracy of dosimeters. Safety concerns (71-4, 87-005, 87-038, 92-048, 

97-176, and 98-073) issued as far back as 1971 reinforced concerns regarding data quality. 

NIOSH has explained that it is possible for a detectable dose not to occur (and therefore not be 

recorded by the dosimeter) even in the presence of high external exposure conditions (NIOSH 

2006j). NIOSH made the following statement in Example 5-1 (NIOSH 2006j): 
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As NIOSH has repeatedly discussed, areas were posted with the maximum 

possible dose rates, and such postings were not intended to be representative of 

dose rates actually experienced by workers. This is an example of just such a 

situation. It is easy to understand how a worker in the field could have the 

impression that he was receiving a high dose (based on postings of maximum 

dose rates) and be perplexed when his dosimetry results did not reflect this. 

These circumstances are unlikely to explain the concerns for several reasons. First, the postings 

used at RFP during this period of time for radiation areas included radiation area, high radiation 

area, and very high radiation area. Based on the dose rate in the room, one of these postings was 

used. Technicians do not recall having to write in dose rates on these postings (refer to 

Attachment 4). Secondly, many of the individuals who have made allegations of inaccurate 

dosimetry readings worked for the radiological control organization and would presumably have 

an understanding of radiation dose and measurement. In fact, they were likely the individuals 

making these dose measurements. Improper understanding of radiological field conditions is not 

likely with these workers. During interviews, site experts listed areas such as the vaults, 

fluorination, americium line, and stacker retriever systems as work locations where the 

phenomenon was observed. RPTs were asked about posting areas at maximum dose rates, but 

did not recall such a practice. Based upon entries in field logbooks reviewed to date, doses in 

routinely occupied areas (e.g., operator’s desk, aisle, control panel) ranged from 3 mR/hour 

to150 mR/hour and reach several roentgens per hour during bag outs (RFP 1965, RFP 1966a, 

RFP 1967). Installation of shielding reduced dose rates but did not eliminate dose. Health 

physics staff tried to maintain exposure rates at work stations of less than 2.5 mrem/hour 

combined neutron and gamma radiation (Putzier 1982). There were times when this level was 

exceeded. For example, senior radiation monitors in Building 771 raised a concern related to 

radiation levels in the general work area exceeding 2.5 mR/hour (JCUSC 1970).

The following case, describing an individual working on the stacker retriever in Building 371, 

serves as an example of the discrepancies between the dosimeter and field exposure data (USWA 

2005): 

In 1982–1983 Loading nuclear material into the Stacker Retriever in Building 

371, 6 quarters out of 8, there is no data available for my dose. This work had 

very high dose. Up to 8 R/hr. Operators assigned were routinely rotated, due to 

the high dose, but as a Radiological Control Technician I was not. 

During interviews, this individual noted that his statement was not intended to claim an absence 

of data but to highlight the absence of dose. Technical Basis for Rocky Flats Plant—

Occupational External Exposure indicated that RFP apparently recorded doses down to zero 

(Falk 2004). If this individual were standing in a radiation field of 8 R/hr for 1 minute, the 

exposure, as measured by a field instrument, would be 133 mR. This exceeds the typical 

minimum detectable dose. Since contact and 1-foot readings were taken at RFP on an 

intermittent basis, it is reasonable to assume an individual could spend 1 minute in an area with 

or approaching the maximum radiation field during the day. Any additional time would increase 

the accumulated dose. The magnitude of dose this individual received from this task is well 
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above all quarterly doses received for 1982 and 1983. The disparity between the field exposure 

rate cannot be explained by a misunderstanding on the part of the individual. NIOSH has not 

produced an adequate explanation for the badge response. 

NIOSH has also chosen not to use secondary sources of radiation exposure data (e.g., chirpers, 

survey results, pencils) when dosimeter results are in question, although these secondary sources 

are often the basis for the comments. Example 19-2 made the following statement (NIOSH 

2006j): 

 

The early “chirpers” were just that—an audible signal to get a “feel” for workers 

when they entered higher fields of radiation. The badges continued to be the 

“legal” record of dose. Later, for the work that could be dose-limiting the new 

generation digital dosimeters were used to monitor on a real time basis the dose 

accumulation on a daily or more frequent basis, with an audit chirp rate also. 

They were used for qualitative controls with the personnel dosimeter being the 

formal dose of record. Workers not familiar with the dosimetry or the control 

procedure intricacies could get the impression that the dosimeters were faulty. 

For example, for a short term job the chirp rate could be elevated, with the 

remainder of the day at lower chirp rates, and the high chirp rate period could be 

the primary recollection because it was unusual, dramatic, etc. This affidavit 

does not present any evidence that “management played with numbers to keep 

techs working in high radiation areas,” nor is NIOSH aware of any such 

evidence. 

In SC&A’s view, NIOSH has disregarded a potential source of data that should be considered in 

the evaluation of unexpected dosimeter values. When using secondary dosimetry as a source of 

additional information on personnel exposure, consideration has to be given to the limitations of 

these dosimeter types. Depending on the particular model of chirper, it is possible for the unit to 

significantly over-respond to low energy x-rays. On the other hand, some of the units will miss 

photons with energies less than 50 keV. Similar issues would be seen with a pocket dosimeter. 

The specifics of the chirpers would have to be evaluated for the particular x-ray field of concern. 

Other secondary dosimetry results such as pocket ionization chambers were not considered by 

NIOSH, but could provide valuable information on the magnitude of dose received by a worker. 

Secondary dosimetry, where worn, could serve as a comparison point against primary dosimetry 

for validation purposes.

In summary, SC&A questions the NIOSH explanation that workers misinterpreted dose rates as a 

result of the practice of posting areas at the maximum dose rates, and that secondary sources of 

exposure information are inadequate. NIOSH has not provided corroborating documentation to 

support its position or evaluated particular instances to demonstrate that its hypotheses are 

correct. The examples provided above show disparity between field readings and dosimeter 

results that are not explained adequately in the NIOSH response. 
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5.5.3 Occurrences of Black Badges 

According to NIOSH, the primary reason badges were blackened was as a result of exposure to 

light and/or heat. In particular, NIOSH stated the following (NIOSH 2006j): 

It is well known that films can also be blackened by exposure to light. In most 

cases, film blackening due to light contamination can be distinguished from 

blackening due to exposure to ionizing radiation. Extreme environmental 

conditions such as exposure to high temperatures can cause film fogging (refs. 

Kathren, R.L., Thermal fogging of personnel monitoring film. Health Physics 12, 

pg. 61–63, 1966, and Brodsky, A. and Kathren, R.L., Accuracy and sensitivity of 

film measurements of gamma radiation—part I. Health Physics 9, pg. 453–461. 

1963). If a badge was blackened due to light contamination, or exposure to high 

temperatures, it is possible that an investigation would have concluded that the 

appropriate dose was low or zero. 

In addition, NIOSH suggested relatively high doses of gamma radiation (500–1000 mrem) could 

cause a film fog making it difficult to analyze the tracks. This would not occur if radiation fields 

were predominantly from neutron dose rates. 

SC&A located a memorandum titled Procedure for Assigning Dose to Dense Neutron Films

(Kirchner and Kittinger 1965), which stated the following: 

During the month of January, there were 21 neutron films reported as “too dense 

to read.” This included 19 from Buildings 76/77/77A and 2 from 71. The 

current procedure is to report these films with a code indicating “too much 

gamma to read,” resulting in an assigned neutron dose of zero. Present plans 

are to adjust the procedure and assign an “average” dose to these films. An 

investigation of the job descriptions and work locations of the 21 personnel 

involved indicated that assigning an overall average dose would not give the 

personnel involved a dose representative of their true exposure. [Emphasis 

added.] 

The memorandum recommends that radiological control operations staff be notified of 

unreadable badges and that they conduct an individual-specific investigation to determine the 

most probable exposure (Kirchner and Kittinger 1965). This statement raises questions 

regarding whether an effort was made to reconstruct dose on an individual basis prior to March 

1965 when the memorandum was issued. It also raises questions regarding how RFP determined 

and documented doses in cases where beta/gamma badges were overexposed. Furthermore, the 

memorandum indicates that average doses may not be representative of the true exposure 

received. 

In response to SC&A’s concern regarding this memorandum, NIOSH indicated that (1) the 

individuals involved were not arbitrarily assigned a zero dose, (2) the memorandum dated 

March 16, 1965, recommends conducting investigations of film “too dense to read”, 
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(3) radiological control staff stated that when there was a problem with dosimeters an exposure 

questionnaire was completed, (4) neutron dose fields were blank on the processing worksheet, 

but a notation was made of no reading, and (5) the NDRP has replaced neutron dose values 

recorded at the time (NIOSH 2006k). 

NIOSH stated that the neutron fields were blank, yet it has concluded that these individuals were 

not assigned zero dose. The 1965 memorandum recommended an investigation, but a record of a 

final dose assignment as a result of that investigation was not found. Presumably, NIOSH based 

this assumption on information from the NDRP. Assuming that the recommendations were 

adopted to investigate badges that were too dense to read, as suggested by Kirchner and Kittinger 

(1965), and exposure questionnaires were completed in this situation, the information should be 

available for review in the personal radiation exposure file or in an alternate location. The lack 

of dosimetry investigation reports (or questionnaires) in personal dosimetry files, as described in 

Section 5.2 of this report, indicates that either these investigations were not documented or that 

the investigation documentation is in an alternate location than the personal dosimetry records 

and thus not provided in the claimant information. Furthermore, the policy of arbitrarily 

recording zero dose prior to March 1965 indicates that neutron data from this era are 

questionable. As indicated by NIOSH, it will assign the dose derived from the NDRP, for 

individuals included in this study. 

In summary, if the issue of overexposed badges was primarily an issue with neutron films, as 

stated under Example 22 from the Data Integrity Samples Analysis 08-25-06 report (NIOSH 

2006j), the NDRP study may correct some of these concerns for individuals included in the file. 

The study will not address high exposures from photons, or neutron exposures for years not 

included in the NDRP study. As discussed in Section 5.2, there is a lack of dosimetry 

investigation documentation available in the individual health physics files containing the 

information used for dose reconstruction. This includes cases where beta/gamma and neutron 

dosimeters were overexposed. NIOSH has not provided substantiation regarding its assertion 

that exposure questionnaires and dosimetry investigations were conducted throughout the 

existence of RFP. Without this information, it is difficult to ascertain how doses from 

overexposed badges were investigated and documented in the record. No definitive method 

exists for determining whether doses were assigned appropriately when badges were black 

without a description of how doses were assigned under these conditions. Clear disposition of 

questionable badge readings is important to the integrity of radiation records upon which dose 

reconstruction is to be performed with “sufficient accuracy” under 42 CFR 82. 

5.5.4 Dosimeter Processing 

The underlying concern with dosimeter contamination, loss, or compromise is that appropriate 

dose was not assigned in those circumstances. The NIOSH response to Example 9-5 regarding 

loss of TLD crystals stated the following (NIOSH 2006j): 

Systems were in place to interpret a badge with a missing crystal, and badges 

contained duplicate crystals. In these cases a dose could be estimated from the 

readings from the remaining crystals. These situations were investigated, and the 
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procedures for doing so were formalized in 4-J88-RDE-0053, "TLD Data 

Investigation and Abbreviated External Dose Reconstruction” and 4-J98-RDE0071, "Extended External Dose Reconstruction.” The results of these 

investigations were documented in the worker’s Health Physics file, and may or 

may not have been communicated to the employee at that time. Since instances 

where badges were missing crystals were investigated, NIOSH concludes that this 

issue does not prevent NIOSH from performing dose reconstructions of sufficient 

accuracy. 

The procedures NIOSH references here were implemented in 1997. Investigations have been 

located in claimant files for this time period. Requests for dosimetry investigations have been 

located for 1990 and 1991. Prior to this time, information is intermittent, especially in the 

individual health physics files. Section 5.2 of this report provides a more detailed discussion. 

In one comment extracted by SC&A from the Advisory Board public comment period held on 

April 26, 2006, the worker stated the following (ABRWH 2006g, p. 355): 

Two chemical operators with many years experience in the Building 771 process 

area left their positions to work in the dosimetry department. The dosimetry 

person training them told them if badges returned readings higher than a certain 

number they were instructed to give the operator zero counts, or no current data 

available. 

Others have also made similar statements during interviews. It is unclear from the statement 

whether this was the practice for the dose of record. This would certainly raises concerns related 

to both individual and coworker data. In the absence of further information, no absolute 

determination on whether data integrity was actually compromised can be made because of the 

lack of corroborating documentation. 

In summary, in situations where the dosimeter was compromised for one reason or another, 

NIOSH contends that RFP conducted external dose reconstructions or investigations. As 

mentioned in Section 5.2, documentation of these dose reconstructions or investigations by RFP 

is lacking in many cases where dosimeter problems occurred, particularly prior to the mid-1980s. 

The substantiation provided by NIOSH is limited to procedures for dosimetry investigations 

from 1997 and 1998, a dosimetry processing procedure for 1983, two examples of investigations 

conducted in 1964 and 1965, respectively, and verbal statements make by former RFP 

radiological control staff. Given currently available data and comments provided by workers and 

NIOSH, it is difficult to determine whether doses for blackened badges were assigned based on 

sound data or individual judgment. 

5.5.5 Contamination Incidents 

Petitioners expressed concern regarding the occurrence of incidents at RFP. In its response to 

petitioners, NIOSH stated the following (NIOSH 2006j): 
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NIOSH grants that incidents occurred during the history of Rocky Flats. 

However, the occurrence of such incidents does not prevent NIOSH from 

conducting dose reconstructions with sufficient accuracy. Incidents were 

reported if they necessitated sending the employee to the Medical Department. If 

a contamination incident could be successfully addressed on the floor, an incident 

report may not have been filed. NIOSH grants that it is not always possible to tie 

an intake to a particular incident. Routine or special request bioassay would 

detect intakes that may have resulted from unreported incidents. The entire point 

of the routine bioassay programs is to monitor for intakes that may not be 

recognized at the time of occurrence and to ensure that internal doses from all 

intakes are kept below regulatory limits. This worker’s radiation file was 

reviewed and it contains numerous incident reports, including every incident 

report submitted in support of this affidavit, plus numerous others. Some 

measurement results showed an activity greater than the level of detection, and 

internal intakes were assigned. All of this data was available and considered in 

the dose reconstruction. 

Incident information can provide valuable data on the nature of intakes that occur as a result of 

the incident. For example, it can define the route of intake or the particular radionuclides being 

processed at the time. Routine or special sampling during these situations can be used to 

calculate dose if the appropriate monitoring was conducted following the incident. 

Unfortunately, the threshold for incident reporting is not clearly defined, and followup bioassay 

may not be requested after incidents not meeting the threshold for the time period. There is a 

missed dose potential for tritium dose from activities in Buildings 371, 771, 776, and 881 if 

sampling is not conducted in a timely manner because of tritium’s short biological retention 

period. NIOSH has developed methodologies to estimate dose from tritium oxide and tritium 

gas in site profiles for other sites and could do so for RFP. The lack of correlation between an 

intake date and a positive bioassay sample is not an SEC issue but should receive further 

evaluation as a site profile issue in the context of best-estimate doses. 

5.5.6 Exposure Geometry and Partial Body Exposure 

According to the petition, badges did not properly record organ dose due to the proximity of the 

organs compared to the badge location. Of particular concern were exposures to areas of the 

body that were not protected when lead aprons were worn. The petition indicated that the head, 

neck, and other exposed portions of the body received higher doses than recorded by the film 

badge located beneath the lead apron. NIOSH responded to this concern as follows (NIOSH 

2006j): 

Lead aprons were available and used for a limited number of tasks at RFP. For 

most years, workers were instructed to wear badges under the lead apron to 

measure dose to the torso. In 1992 this was changed to instruct workers to wear 

the dosimeter outside the lead apron to better measure the dose to the head, neck 

and arms. Field studies to determine the dosimeter response in both locations 

were preformed. The results of these studies were used to develop bias 
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corrections to use for dose reconstructions. The use of lead aprons does not 

preclude sufficiently accurate dose reconstruction. As a result, NIOSH concludes 

this issue does not have SEC implications. 

Furthermore, NIOSH indicated that OCAS-TIB-010, Best Estimate External Dose 

Reconstruction for Glovebox Workers (Neton 2005), can be used to calculate external exposures 

for individuals working in a glovebox. 

Radiation exposures to specific organs have gone uncaptured by the data available from RFP. 

For example, employees routinely removed and did not replace lead-lined or water-shielded 

glove port covers, then would sit in chairs with their heads near the open glove ports. Employees 

wore the dosimeters on their chests or collars, but exposure to their heads went unmonitored. 

The presence of multiple glovebox lines in the same room resulted in exposure of the body from 

multiple angles, including from the side and rear. Another example of nontraditional exposure 

geometry is the receipt of exposure from sources located on the floor, such as in the vaults. In 

some cases, a dosimeter worn on the collar or the chest was not representative of the exposure 

received by specific areas of the body, particularly the lower whole body. NIOSH indicated that 

partial body exposure calculations can be conducted on a case-by-case basis, and that geometry 

issues do not preclude dose reconstruction with sufficient accuracy. 

In summary, NIOSH indicated in the SEC petition evaluation (NIOSH 2006a) that dose 

correction factors for lead apron and glovebox use will be incorporated into the RFP external 

dose TBD or are addressed in TIBs. Although lead aprons protected the front of the trunk, the 

butcher-type aprons did not shield the arms, legs, neck, and face. The site profile review should 

consider further whether the dose correction factor developed for lead apron use is adequate for 

unshielded portions of the body. As long as correction factors can be derived, partial body 

exposures do not preclude dose reconstruction efforts. NIOSH will have to clearly define when 

these correction factors or case-by-case evaluations will be applied. 

5.5.7 High-Fired Plutonium Oxide 

The RFP SEC-00030 petition evaluation (NIOSH 2006a) has raised concerns about worker 

exposures to a unique form of plutonium, referred to as PuO2. This material is formed at 

temperatures of 1,000oC or higher and has been shown to remain in the lung for extended periods 

of time. Concerns were raised by petitioners regarding the ability to detect PuO2 intakes with 

available monitoring methods. According to a presentation prepared by Piltingsrud for the AEC 

(Piltingsrud 1966), intakes of radionuclides can go undetected in the urine: 

For certain refinements in assessing body burdens, a capability for the analysis of 

feces, blood, and tissue samples is necessary. Recently we have found that certain 

internal exposures do not lend themselves to this program.... Specifically we 

have found lung burdens by total body counting which were nearly undetectable 

in the urine. 
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Another concern raised was the appropriateness of the ICRP Publication 66:Human Respiratory 

Tract Model for Radiation Protection (ICRP 1994) for determining dose from uptakes of highfired oxides. As indicated below, NIOSH agreed that this is a significant issue (NIOSH 2006j): 

NIOSH agrees that there is evidence of high-fired Pu oxides at the Rocky Flats 

Plant. The presence of such materials does not, however, affect the feasibility of 

dose reconstructions. ORAUT-OTIB-0049 [ORAUT 2007b] describes the 

methodology NIOSH will use in dose reconstructions potentially involving super S 

plutonium. 

Section 3.0 of the SEC petition evaluation review provides a detailed evaluation of PuO2 dose 

calculations. 

With respect to data integrity, the concern is primarily one of determining the application of the 

ORAUT-OTIB-0049 method. With the release of ORAUT-OTIB-0049 (ORAUT 2007b), 

NIOSH defined the scope for application of their highly insoluble plutonium model. 

Plutonium oxide (especially the high-fired variety) is one of the most insoluble 

forms of plutonium (ICRP 1994, personal discussion with C.W. Sill) typically 

encountered in the workplace. However, it is not feasible to exclude the 

possibility that soluble forms of plutonium might become more insoluble over time 

[La Bone and Findley 1999; Moody et al. 1994]. Therefore, the TIB is assumed to 

apply if the form of the plutonium is not known. This is used as an additional 

possibility of material type; all possibilities are calculated and the type resulting 

in the largest dose is applied to be favorable to the claimant. 

In NIOSH Response to SC&A Draft Report on Data Integrity (NIOSH 2007g), NIOSH stated 

that it had addressed this issue in a December 19, 2006, e-mail exchange between NIOSH and 

SC&A (Ulsh 2006). In response to “Where have you documented which workers will be 

assessed according to OTIB-0049,” NIOSH provided the following answer (Ulsh 2006). 

OTIB-49 is now being finalized. Once it is signed, we will initiate a Program 

Evaluation Report to revisit completed claims with a POC<50% to see which 

should be revised in accordance with the new OTIB. In practice, the claims with 

the greatest potential to be revised are noncomp lung cases, because assuming 

super S solubility is claimant-favorable in these situations. Claims completed 

after OTIB-49 comes into force will be completed in accordance with the OTIB. 

This response merely indicates that noncompensable lung cancer cases will be revisited. In 

addition, a reference is made to a program evaluation report that has, to date, not been made 

available. 

ORAUT-OTIB-0049 acknowledges that plutonium was strongly retained in the lungs of those 

exposed in the October 15, 1965, fire (ORAUT 2007b). SC&A recommends that NIOSH 

consider those exposed in other fires (e.g., 1969 fire, Tunnel fire) and during high temperature 

plutonium processing. D&D workers are also at risk when they come in contact with residual 
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material, especially in areas that only became accessible during the demolition of buildings and 

equipment. Although this is not an SEC issue, a more clearly defined scope in terms of the RFP 

worker categories may assist dose reconstructors in defining individuals potentially exposed to 

high-fired oxides. 

5.5.8 Destruction of Records 

During the Denver Advisory Board meeting, a former RFP worker raised a concern regarding 

radiological records that he was told were sent to the landfill for disposal (ABRWH 2006h). 

NIOSH conducted an investigation by contacting individuals who may have some knowledge of 

the situation. Several other former RFP workers raised similar concerns regarding destruction or 

modification of records. NIOSH concluded the following (NIOSH 2006j): 

NIOSH is not aware of any evidence that records it would use for dose 

reconstruction at Rocky Flats were inappropriately destroyed. Some records, 

such as original personal dosimetry records, are governed by DOE records 

retention policies. Other records are not covered by such policies. Further 

analysis of this concern is not possible without additional details regarding what 

types of records are at issue. 

NIOSH further stated the following (NIOSH 2006j): 

No evidence of fraud was provided either in this affidavit or in the public 

comment made by this individual. NIOSH is not aware of blatantly fraudulent 

Rocky Flats dosimetry monitoring data/records.

The review located no direct evidence that indicated occupational exposure records were 

destroyed. Dosimeter film was disposed of for a subset of workers in the 1969/1970 timeframe 

(Mann 1969d). A more detailed evaluation of investigations into records destruction is provided 

in Section 5.4. 

5.5.9 Conclusion 

Overall, SC&A was able to validate some comments provided by workers in the petition, during 

public meetings, or during interviews, but did not find substantial documented evidence of a 

systemic problem with individual RFP dose records partially due to the lack of data. The review 

raised multiple questions about the validity of the dose records for workers working high dose 

rate jobs, in particular. However, no conclusive documentation was uncovered pointing to 

deliberate falsification or errant recordkeeping despite the numerous sources indicating that this 

was the case. Several references relating to inadequate QA in the dosimetry program were 

identified throughout claimant files, such as inadequate transfer of data between databases. The 

apparent absence of records in 1969 and 1970, as discussed in earlier sections of the report, is a 

significant concern. There is no indication that review of additional information would provide 

corroborating evidence. Information located to date raises questions regarding the adequacy of 
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elements of the radiological control program for some time periods; however, that information 

dose not provide definitive evidence of a systemic issue with the integrity of the data. 

5.6 LUNG COUNTS AFTER THE FIRE 

The 1969 fire investigation report indicated that 110 people were counted as of June 28, 1969, as 

a result of the fire (AEC 1969, pg. 94). NIOSH compiled a list of 69 out of 90 individuals 

reportedly interviewed regarding the 1969 fire. This included first responders as well as 

managers, supervisors, and support staff. The working group requested that SC&A determine 

whether claimants among the 69 individuals received in-vivo counts after the fire. Of the 69 

individuals, 20 had readily accessible files and were identified for review. These individuals are 

recorded in Table 5-6. A review of the health physics file for each person was conducted by 

SC&A to determine whether these individuals received an in-vivo count following the fire. If 

the individual received his exposure within about 1 year of the fire, the table notes the first 

plutonium urine sample data and in-vivo count data after May 11, 1969. Three individuals did 

not receive an in-vivo count in this time period. Of those three, one did not submit a bioassay 

sample. Of the 20 individuals, 14 mentioned some kind of involvement in the 1969 fire in their 

CATI. Nine were in-vivo counted within 1 month after the fire. It is important to understand 

that NIOSH compiled a list of those interviewed about the fire. It did not necessarily involve 

individuals directly involved with responding to the fire. In fact, the list does not include several 

individuals known to be involved with the fire. For example, according to the AEC report, 33 

fireman and security guards participated in fighting the fire (AEC 1969, pg. 58). The NIOSH list 

includes only 18 firefighters and security guards. 

Table 5-7 shows the number of documented in-vivo counts from May to December 1969 

compiled from monthly progress reports. 

More than 200 counts were conducted during 1969 relating directly to the fire along with the 

routine counts. Gross alpha and uranium bioassay processing was curtailed from May 11, 1969, 

through June 1, 1969 (Piltingsrud 1969b). In those files reviewed, there appeared to be a delay 

in bioassay sampling for many individuals after the fire. 

Table 5-6. Postfire Bioassay for Select Individuals Interviewed after the 1969 Fire 

ID Number CATI1 1969 Deep Dose2 In Vitro3 In Vivo4

1 N 3222 6/26/1969 10/17/1969 

2 Y 22 (Partial year only) 6/19/1969 5/12/1969 

3 Y Blank 8/5/1969 No 

4 N 465 7/31/1969 6/26/1969 

5 N 153 (Partial year only) 5/15/1969 5/11/1969 

6 Y 137 (Partial year only) 6/26/1969 7/7/1969 

7 Y 1519 6/23/1969 12/3/1969 

8 Y 38 (Partial year only) 7/9/1969 5/12/1969 

9 Y 749 1/13/1970 5/13/1969 

10 Y 678 5/21/1969 5/11/1969 

11 Y 55 1/13/1970 No 

12 Y 39 (Partial year only) 7/19/1972 3/4/1970 
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Table 5-6. Postfire Bioassay for Select Individuals Interviewed after the 1969 Fire 

ID Number CATI1 1969 Deep Dose2 In Vitro3 In Vivo4

13 Y 813 7/18/1969 8/21/1969 

14 N/A 8 (Partial year only) No No 

15 Y 77 5/15/1969 5/11/1969 

16 N 1831 7/18/1969 4/22/1970 

17 N 351 5/15/1970 4/2/1970 

18 Y 28 (Partial year only) 6/11/1969 5/11/1969 

19 Y Blank 7/16/1969 5/12/1969 

20 Y 

43 (One badge noted as 

contaminated and 

discarded as hot waste) 

5/14/2006 5/12/1969 

1 Mentioned the fire in the CATI 

2 Annual deep dose for 1969. Where “Partial year only” occurs, this indicates monitoring data was available 

for only a portion of the year. 

3 First in-vitro sample submitted on or after May 11, 1969 

4 First in-vivo count on or after May 11, 1969 

Table 5-7. In-vivo Counts Reported for May–December 1969 

Month Total Fire Counts Routines Recounts 

May 287 119 100 47 

Jun 200 12 113 16 

July 195 8 171 38 

Aug 306 5 169 21 

Sept 312 43 191 16 

Oct 349 20 255 29 

Nov 235 0 66 112 

December 283 0 97 141 

5.7 CONCLUSION 

Overall, SC&A was able to validate some of the comments provided by workers in the petition, 

during public meetings, or during interviews, but did not find conclusive documented evidence 

of a systemic problem with RFP dose records. The review raised multiple questions about the 

validity of the dose records for workers working high dose rate jobs, in particular. However, no 

documentation was uncovered pointing to deliberate falsification or errant recordkeeping despite 

the numerous sources indicating that this was the case. Methods for assignment of missed dose 

may underestimate doses received by highly exposed workers. Analysis of individual logbook 

results indicates HIS-20 is incomplete. There was minimal formal documentation of dosimetry 

investigations prior to 1990, although in 1990 and 1991 hundreds of requests were made to the 

field for investigations of unusual results. 
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While further review could answer questions that remain and shed light on the equivocal nature 

of NIOSH’s conclusions for some of the specific issues, there is no indication that such 

additional review would necessarily provide the desired corroborating evidence. Any further 

information would have to be presented either by the petitioners or NIOSH. In this context, 

SC&A has identified issues and inconclusive information related to the integrity of RFP dose 

data but defers to the Advisory Board and its working group to determine how much sampling 

review is sufficient. 
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6.0 INTERNAL DOSE ISSUES 

This section presents SC&A’s review of the internal dose section of the NIOSH evaluation report 

for RFP (NIOSH 2006a). The principle issues discussed in this chapter include the published 

coworker model, evaluation of dose reconstruction examples, and NIOSH’s treatment of the dose 

reconstruction of radiation exposures to americium, thorium, and radionuclides other than 

uranium (natural, enriched, or depleted) and plutonium that were present in historic operations. 

The term “other radionuclides” denotes these radionuclides as a group. 

6.1 OTHER RADIONUCLIDES 

The RFP TBD (Falk 2004) described the overall situation regarding internal exposure potential 

for radionuclides present at RFP as follows: 

Workers at Rocky Flats had the potential to receive intakes of plutonium, 

americium, enriched uranium, depleted uranium, and tritium, as well as 

miscellaneous other radionuclides. Section 5.2 describes the available source 

term information, including isotopic composition, solubility, and particle size. 

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

thorium, curium and neptunium, is rare or not available. [Falk 2004, pp. 7–8] 

The RFP SEC evaluation report (NIOSH 2006a) made the following statement about 

radionuclides other than depleted or enriched uranium, plutonium, and tritium: 

Lastly, there have been a number of special projects involving small quantities of 

other radionuclides. Small quantities of thorium-232 were used in the fabrication 

of metal parts as early as 1952, as mold-coating compounds, and in analytical 

procedures. Thorium-228 was noted as being removed from uranium-233 metal 

in thorium “strikes” during the mid- to late-1960s. Limited amounts of 

neptunium-237, curium-244, americium-241, and plutonium-238 were employed 

as tracers into the make-up of Special Order pits to assist research taking place at 

other facilities, for plutonium-238 as Zero Power Reactor fuel elements, and 

extraction of americium-241 for special applications. None of these other 

radionuclides were present at Rocky Flats in high enough quantities to contribute 

significantly to internal dose potential. (NIOSH 2006a, p. 44) 

The evaluation report does not provide an analysis that demonstrates that these radionuclides 

could not contribute “significantly to internal dose potential.” SC&A’s TBD review (SC&A 

2005c) and the matrix (Item 29 of the March 27, 2006, matrix for RFP) developed from that 

review raised the issue of the dose potential of “other radionuclides.” Since the publication of 

the evaluation report, NIOSH and its contractors (collectively referred to as NIOSH below) have 

done a considerable amount of work on the issues relating to these radionuclides, mainly in 

response to concerns raised by the working group and SC&A regarding the adequacy of the data 

and dose reconstruction methods proposed for these radionuclides. 

 
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6.1.1 Dosimetry Areas and Bioassay Data for other radionuclides 

RFP internal dosimetry areas were divided into four areas (A, B, C, and D), each characterized 

by certain radionuclides. These were, in fact, the original names of the plants given according to 

the code names for the kind of materials processed there. Later, the areas were given building 

numbers. According to the TBD, the kind of bioassay done was specific to the various areas: 

In the beginning of operations (1952), the Rocky Flats Plant was divided into four 

distinct sub-plants, plus a general support area. The sub-plants were named A 

Plant, B Plant, C Plant, and D Plant. The designations A, B, C, and D are 

significant because they are also the code names for the materials processed in 

those plants as well for the urinalysis procedures used to analyze those materials. 

The records of the 1950s do not contain the words: depleted uranium, enriched 

uranium, and plutonium. Instead, depleted uranium is A material processed in A 

Plant (buildings numbered 4##, mainly Building 444); enriched uranium is B 

material processed in B Plant (buildings numbered 8##, mainly Building 881); 

and plutonium is C material processed in C Plant (buildings numbered 7##, 

mainly Building 771). D Plant (buildings numbered 9##, mainly Building 991) 

handled all materials. A nonspecific gross alpha urinalysis method was used for 

workers in D Plant. (Falk 2004, p. 38) 

The TBD describes the methods of analysis as shown in Table 6-1. 

Table 6-1. Methods of Analysis 

A Fluorimeter, reported in micrograms/liter (1952–1956); reported in micrograms/24 hours (1957–1964) 

B1 Electroplating, reported in disintegrations per minute per 24 hours (dpm/24-hr) (Note: electroplating, 

in RFP records, more properly should be called electrodeposition) 

B2 Ether extraction, reported in dpm/24-hr 

B3 Tributyl phosphate (TBP) extraction (handwritten on some cards) 

C1 Carrier precipitation, reported in dpm/24-hr 

C2 Thenoyl trifluro acetone (TTA) extraction, reported in dpm/24-hr (Note: on the header of cards for the 

period 1961–1965, the code C2 is “Pu by Radio Autography”; there is no indication that this method 

was implemented at RFP) 

D TBP extraction 

 Source: Falk 2004, p. 38 

According to the TBD, the following radionuclides are associated with the various types of 

analysis described in Table 6-1 (Falk 2004, p. 38): 

• A = DU 

• B1 = depleted and enriched uranium 

• C1 and C2 = plutonium 

• B2, B3, D = gross alpha 
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In discussions of RFP issues, NIOSH initially stated that when radionuclide-specific data are 

lacking, it would use gross alpha bioassay data and interpret it according to the most claimantfavorable radionuclide present at the facility in question. The evaluation report also makes such 

a statement (NIOSH 2006a, pp. 51–52, exposure scenarios 4, 8, 12, and 16.). While Table 6-1, 

taken from the TBD, indicates that gross alpha data appear to be available only for certain RFP 

areas (B and D, with methods B1 and B2 used in the former case), Roger Falk, NIOSH’s site 

expert, stated that this routine designation of the locations where gross alpha samples were taken 

did not preclude such samples from being taken in other areas in “special situations” (ABRWH 

2006c). 

The depth and breadth of the debate that occurred on these various issues and the turns that it 

took are captured in the transcripts of working group meetings and the associated documents 

(both those produced by NIOSH and by SC&A). This section assesses the final dose 

reconstruction approaches proposed by NIOSH rather than recount the details of the technical 

history of the development of the issues. 

NIOSH performed a significant amount of work on issues relating to other radionuclides based 

on review of classified documents. SC&A did not undertake any classified reviews, as the 

Advisory Board had not authorized any. However, in the final stages of this work, NIOSH was 

able to obtain declassified (with redactions) Th-232 material balance sheets. These material 

balance sheets have been very useful in SC&A’s review of NIOSH’s analysis of the thorium 

source term. 

6.2 AMERICIUM-241 

The Am-241 discussion is divided into two parts: 

• Americium-241 intake estimation: Process streams where Am-241 was abnormally 

concentrated relative to plutonium or was in pure form 

• Plutonium depleted in Am-241: The reliability of using of Am-241 in-vivo counts in 

areas where the plutonium being processed was depleted in Am-241 

6.2.1 Americium-241 Intake Estimation 

Americium-241 purification began at RFP in 1957 in Building 771. It was recovered for resale, 

which continued until the late 1970s. After that time, Am-241 removed from plutonium was sent 

to the radioactive waste streams in Building 774 (Chem Risk 1992, p. 69, and Flack and Meyer 

2004, p. 11). In 1967, a molten salt extraction process replaced the ammonium thiocyanite 

process. 

In response to the concerns about the gap in Am-241 monitoring for operations involving 

separating and purification of Am-241, NIOSH stated that the initial attempts to extract Am-241 

were not successful, as there was very little of it present in the plutonium sent to RFP because of 

the short time that had elapsed after initial plutonium production. NIOSH based its conclusion 
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on expert interviews, as stated by Mel Chew, who led the NIOSH research on other 

radionuclides, during the working group meeting of July 26, 2006: 

If you think about it, the plutonium that showed up at Rocky Flats in the early 

years and in the '50's, prior to '63, was fairly fresh plutonium that came in from 

Hanford. The—the plutonium that didn't come in for the—with the americium 

content was basically out of the recycled plutonium that was in the weapons that 

was in the '50s here, and really didn't come back out of the stockpile until '62, '63. 

All right? And so therefore where we were looking for americium in the early 

years at Rocky Flats, Wanda said it wasn't there. Right? So you know, I think we 

were all obviously looking and said—well, assuming it was there. And matter of 

fact, we confirmed this with a discussion with [Name], and he was responsible for 

developing the process to start—to start to thinking about separating the 

americium from the weapons returned. He made a comment very clearly in this 

document from this discussion with him that they even had a tough time with the 

metallurgist even finding americium to validate the process. Right? And I 

happen to know some parts per million contents that I think the specs that came in 

from Hanford, and Wanda would know this, you know, of her early years, they 

were very, very low. For deliberate purposes. Right? And so clearly the 

americium, I think I can say with a fair amount of confidence that the—where we 

were looking for bioassay, just wasn't there in—in enough significant quantities 

or a few—I'd hate to say a few atoms, to be humorous here—that was enough to 

cause any concern, even—especially they even tried to look for it here. Right? 

But clearly when the weapons returned—did come back in the—in the '63, '64 

time period—which makes sense when you really think about it. Okay? When the 

time period, when we put into the stockpile. Okay? It stays there for a certain 

amount of years, I think all of you know that, and then we got the return. That's 

when the americium content really—really start to come up and the americium 

was separated out, you know, to refresh the plutonium and make better—to make 

weapons grade plutonium back—to go back into the system again. And also the 

americium was now concentrated in a form like the molten salt extraction, both to 

sell the—and sent back to Oak Ridge. And as you know, your americium is widely 

used, you know, throughout the system for many, many other purposes, even more 

than the weapons complex. So I'd like to just make that comment is that we 

cannot see the americium prior to '63, Mark, because it just wasn't there. And 

that makes a lot of sense. [ABRWH 2006c, pp. 19–21] 

This stands as the last definitive statement by NIOSH on the subject of Am-241 monitoring in 

the 1957–1962 period. While it appears to be reasonable as a technical hypothesis, SC&A did 

not perform further verification of weapons returns to RFP, which is mainly in the classified 

arena, and its associated implications for the 1957–1962 period for Am-241. 

Americium-241 bioassay began in 1963 (Falk 2004). However, the TBD advised dose 

reconstructors not to use these data in dose reconstruction due to interference from Th-228-

related alpha particles: 
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The dose reconstructor should use the plutonium urine data instead of the 241Am 

urine data to assess intakes of weapons grade plutonium. The intake of the 241Am 

is then calculated from the value of the initial parts per million of 241Am measured 

or assumed for the plutonium mixture involved in the intake. [Falk 2004, p. 14] 

SC&A raised this issue with NIOSH during the July 26, 2006, working group meeting. NIOSH 

site expert Roger Falk pointed out that any interference from Th-228 present would result in a 

higher value of estimated intake, and therefore the result would be claimant favorable (ABRWH 

2006c, pp. 28–29). SC&A agrees with this conclusion. 

SC&A performed a brief review of the HIS-20 database to check the availability of Am-241 

bioassay data. The number of samples increased steadily from 1963 to 1967. This could be due 

to a ramping up of work and an increasing number of workers involved or a sparseness of 

sampling in the initial period that coincided with an aqueous Am-241 production process. The 

process was changed to a molten salt extraction process in 1967 (ABRWH 2006c, pp. 22–23). 

SC&A raised this issue in its October 27, 2006, memorandum on other radionuclides. NIOSH 

responded, as follows: 

Presumably, SC&A is referring to the number of Am bioassay results in HIS20. 

By our count, there are 475 Am bioassay results in 1963, 1299 results in 1964, 

1227 results in 1965, 1406 in 1966, and 2939 results in 1967. This is consistent 

with Rocky Flats beginning to handle Pu (with ingrown Am) from weapons 

returned from the field beginning in 1963. SC&A has presented no evidence that 

there are gaps in Am monitoring, nor is NIOSH aware of any gaps. [NIOSH 

2006b] 

This NIOSH explanation quoted in full is plausible on its face, but it was offered without 

documentation of an increase in the scale of Am-241. The Am-241 production process changed 

in 1967 from an aqueous to a molten salt process. Hence, dose reconstruction would require 

sufficient records for the period up to the change in process, since the later (post-1967) data may 

not be applicable to the earlier period. The TBD explicitly noted the exposure potential for early 

americium operations to 1967 as follows: 

The process ...was cumbersome, resulted in a disproportionate quantity of waste 

solutions, and created personnel alpha-contamination exposure problems due to 

required manual operations and maintenance. [Flack and Meyer 2004, p. 11]

NIOSH’s statement that SC&A did not find gaps in the Am-241 monitoring is true. However, 

SC&A did not perform the review of classified materials that would be necessary to establish the 

production-related issues associated with such an investigation. 

Lung counting began at RFP in 1964 (Falk 2004). However, meaningful results were not 

obtained until after the 1965 fire. Some of the data present quality issues, notably data 

susceptible to interference from the 63 keV gamma from Th-234. Neither the NaI detectors used 

until 1973 nor the phoswich detectors used until 1976 would have been able to adequately 
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discriminate between the Th-234 and the Am-241 signals. However, as Roger Falk pointed out 

during the July 26, 2006, working group meeting, any Th-234 interference would yield a higher 

in-vivo count and a claimant-favorable result (ABRWH 2006c, pp. 28–29). SC&A agrees with 

this interpretation so long as Th-234 was not also being used for measuring U-238 lung burden. 

SC&A Evaluation: 

In the final analysis, given the significant amount of data available even from 1963 through 1966 

and in the period after that, the Am-241 issue does not appear to be an SEC issue; especially as 

lung counting data whose results are likely to be claimant favorable are also available to 

supplement bioassay data, if needed. 

6.2.2 Plutonium Depleted in Americium-241 

SC&A has raised the question of how in-vivo counts of Am-241 are to be interpreted in areas 

where the incoming plutonium might itself have had low Pu-241 content. In that case, the 

relatively low Pu-241 content would result in relatively low Am-241 content in returned 

weapons plutonium. Purification of such plutonium could lead to removal of Am-241 to very 

low levels. This may make assumptions about Am-241 to plutonium ratios in interpreting invivo count estimates questionable. 

During working group meetings, NIOSH has stated that specifications for weapons plutonium by 

weapons designers required RFP to maintain a certain isotopic composition of plutonium, 

including a specified level of Pu-241. The practice at RFP was therefore to mix aged plutonium 

depleted in Pu-241 with sufficient fresh weapons plutonium to maintain the specified 

requirement. As a result, the situation of very low Pu-241 content in outgoing plutonium would 

not arise. 

On behalf of NIOSH, site expert Roger Falk provided this explanation with regard to Am-241 

levels to be expected in returned plutonium. NIOSH also presented some documentary evidence. 

SC&A concurs with NIOSH regarding the effort made by RFP to maintain Pu-241 levels in 

plutonium. However, according to another site expert, “there were exposures to very low ppm of 

americium, less than 50 to 100 ppm of americium, in Building 771 in the chemical processing 

area prior to the mixing with the aged plutonium.” While in-vivo lung counts were not possible 

under such circumstances, he noted that, “this occurred in the area where the plutonium was in a 

soluble form which made it possible to monitor them with urine bioassay.” 

SC&A Evaluation: 

Since Am-241 bioassay data are available, this would not be an SEC issue. 
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6.3 THORIUM-232 

According to the TBD, Th-232 was present and processed at RFP only in small quantities: 

Beginning in 1952, thorium was used onsite in quantities small enough that 

effluents were not routinely analyzed for Th. Thorium quantities varied from as 

little as none to as much as 238 kg in a given month. The principal use was 

fabrication of metal parts from natural thorium metal (232thorium) and from 

various thorium alloys. Thorium oxide might have been used as a mold-coating 

compound in limited experiments. Thorium compounds were used in analytical 

procedures. In addition, twice between 1964 and 1969, thorium “strikes” were 

performed to remove gamma-emitting 228thorium from uranium-233 metal needed 

for fabrication of test devices. The strikes involved a fluoride precipitation and 

filtration process using natural thorium. Photon radiation from 228Th decay 

products would have been monitored by standard gamma dosimetry badges in use 

at the plant. In addition, thorium was used as a stand-in for plutonium or 

uranium components in development programs (ChemRisk 1992). [Flack and 

Meyer 2004, pp. 9–10] 

This statement reflects a 1976 paper entitled “Thorium Use at Rocky Flats” (Bistline 1976) that 

was discussed by the NIOSH, the working group, and SC&A. An unclassified 1976 document as 

well as compilations prepared by NIOSH of unclassified data from classified sources on the 

thorium issue seem to substantiate that the largest total inventory of thorium present at RFP until 

1976 appears to have been approximately 250 kg. 

The development of the issues relating to Th-232 dose reconstruction has run a rather complex 

course. The following key papers, included as attachments, document that road:5

 

• Attachment 19: NIOSH, Summary of Potential Intake at RFP, no date, published in 

October 2006 

• Attachment 20: Brant Ulsh, Bryce Rich, and Melton Chew, Summary of Thorium 

Handling at RFP, December 21, 2006 

• Attachment 21: SC&A Memorandum to the Rocky Flats Working Group, “Thorium-232 

and Other “Exotic” Radionuclides at Rocky Flat.” October 27, 2006 

• Attachment 22: NIOSH Evaluation of SC&A’s Thorium-232 and Other “Exotic” 

Radionuclides at Rocky Flats—review of NIOSH Papers, November 3, 2006 

5

 This section is an amended version of a draft version prepared for the RFP working group and posted on 

the OCAS web site. That version, dated February 15, 2007, is not included here as an attachment. 
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• Attachment 23: NIOSH Evaluation of SC&A’s Draft Report on Other Radionuclides 

(thorium), February 28, 2007 

• Attachment 24: Interview Regarding Possible Shipments of Alloy from Dow Madison to 

Rocky Flats, February 8, 2007 

In addition, there are extensive working group meeting transcripts, available on the OCAS web 

site and not reproduced here. 

6.3.1 Thorium-232 Source Term 

In its October 2006 paper on the subject (Attachment 19), NIOSH provided data on Th-232-

related work at RFP. The main source term for potential thorium air contamination was stated as 

“Fabrication of metal weapons parts from natural thorium and thorium alloys—machining, 

shearing, grinding” (Table 1, p. 1). NIOSH has stated that the parts from Oak Ridge were 

“trimmed and lightly machine” at RFP (Attachment 19, p. 2). The maximum amount of Th-232 

in such metal parts was estimated at 60 kg per year, and the potential for “unsealed or loose 

contaminants from large metal parts is 10% or less” (p. 4), yielding a source term of at most 6 kg 

per year. NIOSH then applied NUREG-1400, an NRC guidance document, Air Sampling in the 

Workplace (NRC 1993), to this source term to develop an estimate of potential intake for Th-232 

exposure at RFP (see Section 6.4.2.2 for NUREG-1400 discussion). 

SC&A raised two basic questions relating to the source term aspect of NIOSH’s analysis. The 

first related to the magnitude of the thorium processed and the second to the 10% factor used. 

Th-232-related documents had been destroyed at DOE’s Fernald plant in the 1970s (ORAUT 

2004b). While there is no evidence that thorium-related documents have been destroyed at RFP, 

the question arose as to whether such destruction had been a wider policy or whether the 

examined documents represented a complete review of the thorium work at RFP. Furthermore, 

in the case of Y-12, a closer examination of thorium documents had yielded data indicating far 

more thorium processing than NIOSH initially believed. SC&A therefore sought some clarity as 

to the completeness of the thorium source term data that were central to NIOSH’s initial 

conclusion that upper bound doses were very low—so low in fact that they could be ignored 

(since they were less than 1 mrem in the worst case) (ABRWH 2006d, pp. 213–214). However, 

SC&A’s concerns regarding the completeness of the thorium source term were broadly 

addressed by the declassified materials balance data and recent communications with NIOSH, 

though some uncertainties remain (see Section 6.4.1.1). 

NIOSH revisited the source term question with regard to the amount of thorium metal processed 

over the years (as distinct from the amount in the RFP inventory at any time). In its 

December 21, 2006 report (Attachment 20), NIOSH stated that three thorium metal parts, each 

weighing about 80 kg, were rolled from 12 in. x 12 in. x 3 in. ingots to metal bars between May 

and September 1960. Canning of the ingots in mild steel was also performed. According to 

NIOSH, only 12 workers were involved. An incident occurred during hot rolling of the third 

ingot in September 1960, and the ingot was cut with a torch and eventually scrapped (see 
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Attachment 20). Ingot 2 was also scrapped. This new information about thorium processing was 

presented in the December 21, 2006, report (Attachment 20), but not in the prior (October 2006) 

NIOSH analysis (Attachment 19). While this new information did not change NIOSH’s October 

2006 estimate of the maximum inventory of Th-232 at RFP in any year (Attachment 20), it did 

increase the maximum amount estimated to be processed in any year by a factor of four—from 

approximately 60 kg (plus small amounts in various processes) to 240 kg for canning and rolling. 

However, it should be noted that the rolling of these three ingots was experimental, and that 

SC&A has not come across evidence of further rolling operations. 

6.3.1.1 Thorium-232 Material Balance Data 

To facilitate the SC&A review, NIOSH undertook to have the RFP thorium material balance 

sheets declassified. SC&A has reviewed this declassified document (RFP 2007). To the extent 

the data are available and interpretable, they corroborate the NIOSH source term. However, they 

are incomplete in certain periods. 

Table 1 of the NIOSH October 2006 paper on thorium (Attachment 19) states that thorium was 

handled and processed at RFP between 1956 and 1993 for the “[f]abrication of metal weapons 

parts” and the “[f]abrication of thorium substitute R&D components.” It also shows that the 

analytical laboratories used thorium from 1952 to 1993. SC&A understands that thorium 

processing and use was a sporadic activity at RFP and has taken this into account in its analysis 

of the materials balance data. 

The declassified records show that a monthly balance for thorium was maintained. The records 

start on March 1, 1953. Hence, no record is available for 1952 and the first two months of 1953. 

There is also a 1.5-year gap in the data between July 1, 1953, and January 1, 1955, when no 

monthly balance sheets are available. Finally, almost no data are available between July 1970 

and 1987 (inclusive) and only sporadically after that. The gaps are documented in the 

declassified record itself and summarized in Table 6-2. 

In addition, the material balance compilation does not show any data for 1952 or January and 

February 1953. There was a beginning material inventory of 5 kg of Th-232 on March 1, 1953, 

indicating receipt of thorium in the period between 1952 through February 1953. Whether any 

processing occurred during this period is unknown. 
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Table 6-2. Time Gaps in Thorium Material Balance Data as Indicated in the Data 

Dates Comments 

July 1953 to December 1954 (inclusive) 

July 1970 to May 1982 Except for normal operating loss summary (annual) though September 

1974 

June 1983 to June 1985 (inclusive) 

August 1985 to July 1987 (inclusive) 

October 1989 to February 1990 (inclusive) 

April 1990 to January 1991 (inclusive) 

March 1991 to 1993 (inclusive) 

 Source: RFP 2007 

For some periods, the gaps in the data shown in Table 6-2 may mean that documents are 

unavailable for certain time periods, since the materials balance for thorium was performed every 

month at least into the 1970s, even in the months when there were no receipts and no 

withdrawals. For the period from July 1953 to December 1954, RFP may not have had any 

thorium inventory. The ending balance for June 30, 1953, was zero, as is the starting balance on 

January 1, 1955. Of course, this is not conclusive, but rather evidence that indicates a lack of 

thorium receipts or processing in this period. A definitive statement cannot be made based on 

the available information.6 

The last sheet in the materials balance records provides an annual summary of the normal 

operating losses from 1952 until September 1974. This summary indicates zero normal 

operating losses for the FY (July 1 to June 30) 1952 and FY 1954 and negligible losses in FY 

1955. This provides further evidence supporting a lack of thorium processing during these 

specific periods of data gaps. 

For the data gap between July 1970 to September 1974, the normal operating losses data sheet 

lists losses as zero or negligible in all years except FY 1971, when losses are listed as 1 kg. (The 

rounding in the material balance sheets is generally to the nearest 1 kg of Th-232.) An addition 

to normal operating losses of 1 kg between September 1974 and 1976 may be inferred from other 

available documentation. No RFP thorium data of any kind are reported between 1976 and May 

1982; the gap in the materials balance sheets for this period extends from July 1, 1970, to May 

1982. 

 6

 SC&A sent an inquiry about the nature of the gaps in the data and received the following response from 

Brant Ulsh: “I asked Rod Hoffman about this when he sent us the declassified MBA ledgers. Rod said that the 

periods with no inventory sheets (last half of 1953–end of 1954, and last half of 1970 through Sept. 1987) are 

consistent with no reportable inventory being onsite during those periods. This is supported, for instance, by the 

inventory sheet for June, 1953. Note at the bottom it has the following note: “Composition of Ending Inventory: 

No inventory on hand.” There are no further sheets until January, 1955” (Ulsh 2007). However, as discussed in this 

analysis, this argument applies to the 1953–1954 gap and the post-1982 gaps, but not the 1970–1982 gap. 
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The materials account shows an ending balance of 102 kg on June 30, 1970, and a starting 

balance only 1 kg in June 1982. All available data after June 1982 show a material balance of 1 

kg. While the data do not exist or are not available for several years in the 1980s, there is no 

indication of any deviation from a 1-kg material balance. 

The declassified materials balance data contain no explanation for the removal of 101 kg from

the thorium inventory between June 20, 1970, and June 1, 1982. In response to a query from 

SC&A about the data gaps, NIOSH gave the following response regarding the inventory of 102 

kg at the end of June 1970 and its reduction to 1 kg: 

Arjun: 

Here is some additional followup info on your question about the Rocky Flats 

thorium inventory ledgers. We talked to DOE headquarters, and they checked the 

information on the Nuclear Materials Management and Safeguards System 

(NMMSS) database for the fate of the thorium present at Rocky Flats as of June 

30, 1970. Recall that we have a Material Balance and Inventory ledger for that 

month showing an ending inventory of 102 kg. From DOE NMMSS documents, 

the same quantity was reported on September 30, 1970. As of December, 1970 

the inventory dropped 1 kg. The inventory remained unchanged through March 

1971. There was then a shipment which comprised >95% of the RFP thorium 

inventory from RFP to Fernald on June 14, 1971. This is consistent with Fernald 

being designed as the repository for thorium in the DOE complex right around 

that time. From the MBA ledgers file currently on the O drive, there are 

inventories of 1 kg listed for the 6/1/82–5/31/83, 7/85, and 10/87 reporting 

periods. There is also a report dated 3/28/90 that specifies 1 kg of solid thorium 

compound present in Bldg 371 as a standard. I surmise from this that after the 

shipment to Fernald in 1971, the only thorium left onsite at Rocky was this 1 kg 

standard. 

Regards, 

Brant

This is a plausible explanation for the inventory change. Fernald was designated as the national 

thorium repository site in 1972 (ORAUT 2004a, p. 10). The shipment of thorium inventory no 

longer needed at RFP to Fernald is compatible with that fact, as noted by NIOSH. SC&A has 

not reviewed the DOE materials safeguards database (which may be classified); according to the 

e-mail quoted above, NIOSH appears to have obtained the information verbally from DOE. 

Finally, the shipment of thorium to Fernald does not definitively settle the question of whether 

thorium was shipped in to RFP, processed, and shipped out some time during the period of the 

data gap. 

In reviewing the material balance records that exist, it is not possible to relate those records to 

specific periods of processing at RFP. But the data are broadly consistent with the one major use 

of thorium at the site that is documented—the ingot rollings between June and September 1960 
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(in two different fiscal years). Data show receipts approximately corresponding to the amounts 

processed. An entry of total material removed of 172 kg was made for May 1961, and a 

cumulative entry for removal of 209 kg in that fiscal year to date was shown as well. This is 

likely related to the two ingots that were scrapped and one that was shipped; however, the 

material balance sheets contain no direct evidence of what was shipped. 

The manner of the entries for normal operating losses creates some uncertainty regarding the 

times and amounts of processing. The summary sheet for these losses (p. 253 of the material 

balance document’s pdf file) showed that almost half the cumulative losses of 31 kg are 

attributed to just 2 years—9 kg in FY 1964 and 6 kg in FY 1967. However, the materials 

balance sheets for these years did not indicate that large amounts of Th-232 were processed 

during that time. Attribution to losses may have occurred in years after the losses were incurred, 

but that cannot be established from the monthly data. In other words, the unevenness of the 

amounts attributed to losses may be due to data recording practices regarding losses. SC&A 

noted that the data for normal operating losses for FY 1964 in the monthly balance sheets do not 

show the same amount for the year as the summary sheet. Ten kg are attributed to cumulative 

fiscal year losses in the June 1964 data sheet (p. 122 of the pdf file) versus 9 kg in the summary 

sheet. 

It is possible that an annual operating loss of 9 (or 10) kg implies considerable processing in that 

year but no offsite shipments. However, this cannot be established from the available data. This 

uncertainty may especially affect workers who were at RFP for a few years, since the annual 

attribution of thorium exposure over long periods would not be available to them to balance out 

positive and negative source term errors. 

Finally, NIOSH has indicated that 32 kg of normal operating losses are compatible with the 

available data: 

It is not clear why the reference to a cumulative total of 32 kg Normal Operating 

Losses indicates operations beyond those discussed in NIOSH’s December 27, 

2006 report, especially when the 1960 Th ingot operation itself resulted in two of 

the 80 kg ingots being scrapped. The Normal Operating Losses are tracked on 

the Materials Balance and Inventory ledgers used by NIOSH in calculating the 

thorium source term. [Attachment 23, p. 5] 

The declassified materials balance data do not clarify this point because the scrapping of two 

ingots, 80 kg each, does not appear in the normal operating losses. These ingots were probably 

shipped offsite in FY 1961 (as noted above) and shown as removals in the materials balance 

sheets. 

SC&A Evaluation: 

No information in available materials balance sheets or other data sources contradicts NIOSH’s 

conclusions about thorium processing at RFP. Taken as a whole, the material balance sheets are 
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broadly consistent with NIOSH’s assumptions about the thorium source term. SC&A agrees 

with NIOSH that the maximum amount of thorium at RFP was approximately 250 kg. 

Attribution to normal operating losses was highly nonuniform. Nearly half the cumulative losses 

up 1976 occurred in just 2 years, FY 1964 and FY 1967. It is noteworthy that neither was the 

year of the largest processing—the ingot canning and rolling year—1960. The available data are 

insufficient to establish whether much more processing than usual occurred in these two years 

(apart from 1960) or whether the losses recorded in those years actually occurred earlier. 

6.3.1.2 Magnesium-Thorium and Tungsten-Thorium Alloys 

NIOSH has also reviewed a number of other potential sources of thorium exposure. In its 

December 21, 2006, report, NIOSH also reviewed whether RFP received thorium from the Dow 

Madison plant and concluded that no pure thorium shipments occurred between these two sites: 

A review of transcripts of the interviews of Dow Madison workers upon which this 

question is based reveals that the Dow Madison workers were clearly speaking of 

shipments of magnesium alloy, of which thorium is a minor component (up to 

three percent according to the workers). NIOSH further verified this with a 

follow-up interview of the worker who spoke of shipments of material between the 

Dow Madison Site and Rocky Flats. In this follow-up interview, the worker 

recalled frequent shipments to Rocky Flats, and he stated unambiguously that the 

material was magnesium alloy, not thorium metal. He did not recall the Madison 

Site ever shipping pure thorium metal to Rocky Flats or anywhere else. 

[Attachment 20, p. 7] 

 

The December 21, 2006, NIOSH report does not provide conclusive information about alloy 

shipments to RFP or their exposure potential once received there. During the January 9, 2007, 

working group teleconference call, NIOSH stated that the worker interviewed on this topic 

remembered that alloys were shipped by the truckload. SC&A conducted a followup interview 

with a former Dow Madison worker who participated in the shipping process from 1963 to 1975. 

Attachment 24 provides the interview summary. According to this worker, about four truckloads 

per month were shipped from Dow Madison to RFP, with each truck carrying about 40,000 lb of 

magnesium-thorium alloy. He also remembered that RFP returned magnesium-thorium alloy 

scrap. If this information is correct, the annual source term for the thorium contained in the 

sheets of alloy shipped to RFP would be in the tens of tons. 

On the other hand, senior former RFP personnel interviewed by NIOSH have stated that RFP did 

not receive large quantities of magnesium-thorium alloy. None of the personnel remembered 

shipments from Dow Madison. Furthermore, according to the NIOSH paper of February 28, 

2007, the parts that were used at RFP were not fabricated there (Attachment 23): 

The four site experts subsequently interviewed were unanimous in their view that 

there were not large quantities of magnesium alloy used at Rocky Flats, and none 

of the interviewees remembered shipments of such material between Dow 
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Madison Site and Rocky Flats. The one use of Mg alloy remembered was the 

pennants in the conveyor line in Building 776, which involved possibly a few 

hundred pounds of alloy at most. It was not clear whether or not this magnesium 

alloy contained thorium. It was also stated that the pennants were fabricated 

offsite by an outside vendor. [NIOSH February 28, 2007, Attachment 23, p. 7] 

The contradictory testimony, implying a difference of several orders of magnitude in the 

potential magnesium-thorium alloy source term, between the Dow Madison worker who was 

involved in the shipping process and RFP site experts interviewed by NIOSH has not been 

resolved. It would have taken a considerable effort to attempt to locate shipping and receiving 

records for the Dow Madison plant, for instance, to produce supporting documentary evidence. 

The working group did not authorize such an undertaking. The RFP petitioner offered to locate 

fellow former RFP workers with recollections of historic magnesium-thorium alloy use. SC&A 

followed up with calls to the petitioner and attempted to obtain corroborating information 

regarding Dow Madison shipments of magnesium-thorium alloy to RFP, but was unable to 

obtain substantive data that would help resolve the conflicting statements. SC&A also contacted 

other former RFP workers, but obtained no corroborating information to substantiate Dow 

Madison shipments of magnesium-thorium alloy to RFP or to describe its applications there. 

This may have occurred because none of the workers SC&A was able to contact about this issue 

was employed at RFP during the period in question. 

SC&A Evaluation: 

A difference of interpretation remains between NIOSH and SC&A regarding the magnitude and 

nature of the magnesium-thorium alloy source term due to contradictory interview statements 

and lack of documentation to resolve the large differences implicit in the statements made by site 

experts from both the Dow Madison and RFP sites. However, subsequent followup with RFP 

petitioners and former RFP workers produced no corroborating information to substantiate Dow 

Madison shipments of magnesium-thorium alloy to Rocky Flats, nor did investigations find any 

further information about its applications there. 

6.3.1.3 Tungsten-Thorium Alloy Welding Rods 

NIOSH has agreed to develop a complex-wide intake estimate for tungsten-thorium welding 

rods. It also presented an analysis of the issue in its February 28, 2006, paper on thorium at RFP 

(Section 6 of Attachment 23). SC&A has not reviewed the underlying literature in detail, but is 

in qualitative agreement that sufficient data on welding with tungsten-thorium alloy exist to 

enable bounding intake estimates. It is therefore not an SEC issue. SC&A will address it 

separately as a generic issue in dose estimation should the Advisory Board ask it to do so. 

6.3.1.4 Overall Conclusions Regarding the Thorium Source Term 

SC&A concludes that, while new information continued to emerge during the course of this 

review, no information in available RFP materials balance sheets or other data sources serve to 

contradict NIOSH’s conclusions about thorium processing at RFP. Taken as a whole, the 
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material balance sheets are broadly consistent with NIOSH’s assumptions about the thorium 

source term. Therefore, SC&A does not consider this to be an SEC issue under the 

circumstances. 

6.3.2 Estimating Thorium-232 Intakes 

This section will first consider the ingot operations in 1960 and then discuss NIOSH’s approach 

to estimating doses from other thorium processing. 

6.3.2.1 1960 Thorium Ingot Operations 

Leaving aside the reservations about the source term discussed above, SC&A has concluded that 

it should be possible to make a bounding dose estimate for ingot operations in 1960. These 

operations are described in detail in a document from the period (Calabra 1961). Some bioassay 

data are available, and the minimum detectable amount is known. RFP carried out monitoring of 

the rolling of the thorium ingots. Limited air concentration data are also available for some of 

the specific operations, including the incident in September 1960. 

In its December 21, 2006, analysis, NIOSH presented its approach to estimating doses from the 

operations conducted with the 80-kg ingots using air concentration data. For the operation on 

June 3, 1960, one air sample was at 4.62 dpm/m3

, while the others averaged 1.41 dpm/m3. 

NIOSH has combined these data with documented estimates of the times of the operations to 

estimate intakes for rolling part of the operations. It made a separate estimate for the flamecutting of thorium related to the September 1960 incident, during which time special air samples 

were taken (Attachment 20). 

The June 3, 1960, air samples are not indicated in the data sheets as breathing zone samples. The 

use of general air samples whose location is not well specified to estimate intakes for particular 

workers could result in underestimates, despite some conservatisms in NIOSH’s calculation. 

The use of general air concentration data (or data whose nature in relation to the worker 

breathing zone is not well known) is not recommended. This was discussed at length in the 

context of the SC&A review of the Bethlehem Steel site profile and the resolution of the issues 

that followed. If air concentration data are to be used for RFP, the bounding nature of the data 

should be established by comparing the values with air concentrations measured at other sites. 

The flame-cutting of an ingot on September 22, 1960, was documented and some air 

concentration data are available (Attachment 20). However, the number of samples is rather 

limited—four in all (Air Sample records 1960). NIOSH has identified one of these as a 

“breathing zone” sample (Attachment 20); however, the raw data card itself only stated that the 

sample was taken “3 ft. from thorium ingot while it was being cut.” This is more than an arm’s 

length; it farther than the operator would be from the ingot during the cutting operation; hence, 

the sample is unlikely to reflect a true breathing zone concentration. In such circumstances, a 

short distance of a foot or two can make a considerable difference in air concentrations. Hence, 

the actual breathing zone of the worker doing the cutting may have been higher, possibly much 

higher. Furthermore, the sampler airflow rate was rather low at 1.7 ft3/min. The rate is not much 
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more than might be breathed during very heavy work. SC&A provided a detailed discussion of 

the flame-cutting issue and possible air concentrations derived from welding data in its 

supplement to the Bethlehem Steel site profile review (SC&A 2005b, Attachment 4). 

Bioassay samples were taken on September 29, 1960, during the pulling of the broken ingot (#3) 

for the can. 

In conclusion, the available air concentration data, taken by themselves, are too sparse to create a 

bounding dose estimate for ingot operations. They should be compared to data from other sites 

to validate that the estimated doses are bounding (or not). If this is done, NIOSH should be able 

to establish a bounding dose estimate. The procedure specified in its December 21, 2006, 

document does not definitively establish such a bounding dose due to the limited data available 

and the fact that NIOSH did not use the bioassay data. The flame-cutting operation for one ingot 

should be compared to some of the welding air concentration data discussed by SC&A in its 

Bethlehem Steel site profile review. 

6.3.2.2 Machining of Thorium Parts from Oak Ridge 

NIOSH has conducted an extensive analysis of the applicability of NUREG-1400 to the 

estimation of thorium intakes for operations at RFP other than the ingot operations discussed 

above. They include the operations that NIOSH has described as requiring “light” machining of 

parts received from Oak Ridge, which constitutes the main remaining Th-232 source term that 

NIOSH has described (Attachments 19, 20, and 23). 

NIOSH’s intake estimate based on its use of NUREG-1400 for light machining of 60 kg of 

thorium parts annually was initially 0.024 Bq per year (Attachment 19). This estimate used a 

10% loose material factor to reduce the source term by a factor of 10. While NIOSH continues 

to believe that this is adequate to estimate bounding dose, it agreed in its February 2007 

assessment to drop the factor of 10 and hence increase the intake estimate to 0.24 Bq per year 

(Attachment 23, Section 5). 

NIOSH has carried out some validation exercises for the use of NUREG-1400. In its December 

2006 report (Attachment 20), NIOSH used the following comparison: 

A study of air activity measured from similar machining and/or grinding 

operations was conducted to validate the estimate derived using [the] NUREG1400 approach. Thus an extensive study by scientists of the AEC Health and 

Safety Laboratory prior to 1958 was referenced which presents air sampling data 

from a number of facilities in which a variety of processes were used in the early 

1960s time period for processing of uranium. This study was with uranium being 

processed in large quantities for extended time period of production operations 

and present a much greater contamination release potential than the light 

machining or grinding of relatively small pieces of thorium metal during 

relatively short time periods, but can be used in a high bounding comparison. 

The releases from similar processes, i.e., milling, grinding, etc., on uranium as 
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compared to thorium is also conservative/bounding based upon the differences in 

the physical characteristics. The melting point for uranium metal is 1690 C and 

for thorium metal 1845 C. The boiling point is 3500 C for uranium and 5200 C 

for thorium. Thus values derived for thorium air activity based upon the direct 

comparison with uranium results below will be higher than those anticipated for 

thorium. 

The air activity levels for the machining and grinding operations, which were 

performed on the uranium metal parts, were converted to mass concentrations, 

which were then converted to thorium activity concentrations. This is based upon 

the assumption that equal mass quantities of thorium to those of uranium would 

be released. Since thorium metal, oxides and hydroxides are considered 

insoluble, solubility class S dose conversion factors were used. 

Since the work with thorium metal parts was performed on equipment designed 

for enriched uranium at the Rocky facilities, the machines were shrouded/hooded 

and were considered in the “vented” category listed in the reference study.

[Attachment 20] 

Table 6-3, reproduced from the NIOSH report, shows the results obtained. 

Table 6-3. Calculation of CDE and Annual DE Dose (in mrem) 

mrem DE mrem Operation dpm/m3

U μgU/m3 dpm/m3Th hr/yr Bq intake CDE 1st yr 20th yr 

Machining 50 64 16 10 3.1 44 bs 0.25 bs 6.5 bs 

24 lung 5 lung 0.3 lung 

Grinding 200 257 63 10 12.6 176 bs 1.0 bs 27 bs 

97 lung 21 lung 1.6 lung 

Key: bs = bone surfaces, lung = lung as the organ of reference. For reference, the annual dose equivalent in 

mrem is given for the 1st year after intake and the 20th. CDE = Cumulative dose equivalent is derived by 

multiplication of the intake by the dose conversion factor from ICRP 68 (ICRP 1995) in Table 3. 

Source: This is a reproduction of Table 6-1 in the NIOSH December 21, 2006, paper (see Attachment 20).

Both the machining and grinding intakes are higher than the highest value of intake (0.24 Bq) 

that NIOSH has derived from the application of NUREG-1400. In SC&A’s view, the example 

does not establish that NUREG-1400 provides an adequate basis for making a bounding dose 

estimate. In fact, since the intakes are well over an order of magnitude higher than the new 

NUREG-1400 estimate, SC&A finds that the comparison reinforces its reservations about the 

utility of using NUREG-1400 for the stated purpose. 

NIOSH has also provided two other examples of its validation of the use of NUREG-1400 

(Attachment 23). In both cases, a NUREG-1400 intake estimate is compared with that derived 

from air concentration data. 
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In the first example, NOISH used a 1953 thorium source term based on Simonds Saw and Steel 

air concentration data and compared it to one derived from NUREG-1400 based on the source 

term. The latter estimate was 315 Bq, while the former was 196 Bq. In other words, according 

to NIOSH’s estimate, the NUREG-1400 estimate exceeded that derived using air concentration 

data for the same work by a factor of 1.6. The air concentration used was the highest among the 

weighted averages estimated for different groups of workers. 

This example indicates that NUREG-1400 could be an adequate tool to estimate average 

working conditions for groups of workers. However, the use of weighted averages, particularly 

with small numbers of measurements for each task, is not appropriate for making bounding dose 

estimates for individuals. SC&A has discussed this issue in detail in relation to an analysis of 

potential worker exposure at the Mallinckrodt Chemical Works and the SEC petition that was 

filed in that context. Specifically, SC&A showed that the uncertainty in a single step, which had 

three air concentration measurements associated with it, could result in a 95th-percentile intake 

estimate that was more than double the one derived from the weighted average. In light of that 

analysis, SC&A concluded that weighted averages could only be used to make minimum dose 

estimates (SC&A 2005a, pp. 27–29). In other words, it is inappropriate to use them for bounding 

dose estimates. 

The situation in the case of Simonds data is about the same. The value of weighted air 

concentration used related to only two workers—“Finisher North” and “Hookman North” 

(Klevin and Weinstein 1953). For Finisher North, only two measurements were associated with 

the task that indicated the highest air concentration. The same is true of Hookman North. In 

fact, the raw data sheets for these two workers indicate that the same air samples were used to 

estimate the weighted average for both workers. Hence the entire comparison rests on two air 

samples for a single task that accounts for about three-fourths of the total weighted exposure. Of 

course, with only two samples, estimating a 95th percentile is itself fraught with methodological 

problems, but assuming that a lognormal approach can be applied, the 95th percentile value 

would be over 400 Bq—that is greater than the value derived using NUREG-1400. Hence, while 

this example indicates the plausibility of using NUREG-1400 for estimating average doses for 

worker populations over long periods of time, it does not establish the validity of NUREG-1400 

as a method for estimating a bounding dose for RFP thorium workers. This reservation is 

especially important if operations were sporadic or if they involved unique processes that were 

not repeated, such as the flame-cutting of a thorium ingot. 

The second example, which used the single air concentration measurement taken 3 ft from the 

job on September 22, 1960, at RFP, is statistically even more tenuous. Contrary to the NIOSH 

description, the raw data card did not describe this as a breathing zone sample; in fact, it is 

unlikely that it was a breathing zone sample. There is also no way to estimate an uncertainty for 

the breathing zone, even if one accepts this single measurement as such, since there is only one 

data point. 

In conclusion, NIOSH’s analysis has established the plausibility of using NUREG-1400 to obtain 

a general view of working conditions on average. However, the examples provided do not 
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validate the use of NUREG-1400 for estimating a plausible upper bound dose for individual 

workers at RFP that would meet the criteria of 42 CFR Part 83.

6.3.2.3 Thorium Air Concentration Data from Comparable Operations 

Three studies described below (Albert 1966, Adley et al. 1952, and Harris and Kingsley 1959) 

provide extensive data on air concentrations measured during various thorium processing 

operations at a number of different sites. These analyses provide a large amount of data that 

could be analyzed for applicability to RFP. As described in this section, SC&A has evaluated 

these reports. 

The exposure pathway of greatest concern with respect to the machining and other operations 

with thorium metal and metal alloys containing thorium is inhalation of particles produced 

during those operations. At the working group meeting held on March 7, 2007, SC&A suggested 

that a more appropriate strategy might be to use the empirical data for uranium and thorium 

grinding operations published in the Albert and Adley reports, respectively. These reports 

appear to provide data directly applicable to the exposure scenarios of concern at RFP, as 

opposed to the more generic models and assumptions provided in NUREG-1400. 

A report on uranium dust in machining and other operations by W. Harris and I. Kingsley, The 

Industrial Hygiene of Uranium Fabrication (Harris and Kingsley 1959), is also relevant. This 

section summarizes the data in those portions of these three reports that deal with the machining 

of uranium and thorium. This information discloses the range of uranium and thorium dust 

loadings, typically expressed in units of mg/m3

, that have been observed in the breathing zone of 

workers involved in the machining of uranium, thorium, and alloys containing thorium. Once a 

more complete understanding is gained regarding the conditions under which thorium was 

machined at RFP, the data provided in this section can be used to select dust loadings that can be 

used to reconstruct doses to RFP workers who might have been involved in the machining of 

thorium and alloys containing thorium and for whom NIOSH now proposes to use NUREG1400. These data should also be used to complement the sparse data available for the 1960 ingot 

operations to ensure that a suitable bounding estimate of dose is developed. The reports contain 

job-specific air concentrations and time-weighted data. Under the circumstances at RFP, with 

intermittent thorium operations, the use of daily weighted averages from other sites would be 

inappropriate. But the task-specific data from other sites can be used with the knowledge of job 

durations at RFP to estimate intakes. 

The Albert Report 

In 1966, Academic Press published a comprehensive manuscript entitled Thorium, Its Industrial 

Hygiene Aspects (Albert 1966). Based on its review of the literature, SC&A believes that this 

manuscript remains the most authoritative reference on the industrial hygiene aspects of thorium. 

Chapter 10 of the manuscript specifically addresses the inhalation hazards of thorium in industry. 

In particular, Section 2, “Thorium Fires,” Section 6, “Rolling, Forging, and Machining,” and 

Section 7, “Thorium-Magnesium Alloys,” appear to be either directly or indirectly related to 
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characterizing the airborne dust loading that might have been experienced by workers at RFP 

involved in machining thorium metal and/or alloys containing thorium. 

Table 10.4 of the manuscript presents data on the concentration of thorium in the breathing zone 

of workers involved in melting, machining, and forging thorium. Table 6-4 presents excerpts 

from this table that address various steps associated with machining thorium. (It is assumed that 

thorium melting and forging operations were not performed at RFP.) 

Table 6-4. Excerpts from Table 10.4 of Albert (1966)—Concentrations in Breathing 

Zone Air Samples (μCi/ml) 

Operation Sampled Number of 

Samples Collected Alpha Decay Beta Decay 

Machining After 24 

hours 

After 2 

weeks 

After 24 

hours 

After 2 

weeks 

 Machining ingots and electrode stubs 

 Lathe equipped with local exhaust 

 hose 6 2.49E-9 3.12E-10 1.97E-9 4.59E-10 

 Lathe enclosed in hood 5 3.9E-10 1.70E-11 5.18E-10 3.1E-11 

 Sawing ingot (dry) 1 3.5E-11 Note** 1.08E-10 Note* 

 Crushing and pressing turnings 2 9.59E-10 2.72E-10 1.54E-9 9.67E-10 

* Not measured 

Source: Lowery 1962 

It is difficult to determine how much of the alpha activity is due to Th-232, Th-228, and Ra-224 

and its progeny because one would expect Ra-224 (with its 3.64-day half life) and its short-lived 

progeny to grow rapidly after thorium separation. One would expect the samples taken after 2 

weeks to have higher alpha activity than those taken after 24 hours. However, in the table, the 

samples taken after 24 hours appear to have the higher alpha activity. In order to ensure that the 

exposures are not underestimated, it is prudent to use the highest measured values as 

representative of the thorium breathing zone concentrations during machining operations. 

Consideration must also be given to the number of hours per year a given individual might be 

involved in machining operations. Evidently, the matter of exhaust ventilation is important and 

data are available that include the use of such ventilation, as noted in the table above. 

The Adley Report 

The amount of data in Albert (1966) characterizing the dust loading in the breathing zones 

associated with machining thorium is limited. However, it includes considerably more data 

characterizing the dust loading in the breathing zone of workers involved in machining uranium. 

Since uranium is more pyrophoric than thorium, data characterizing dust loading associated with 

machining uranium can be used as conservative surrogates for machining thorium. One of the 

investigations that provides considerable data on the dust loading associated with machining 

uranium is the Adley et al. report (1952), referred to hereafter as the Adley report. This section 

summarizes the pertinent data provided in that report. 
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The Adley report presents the results of a detailed investigation of the health physics issues 

associated with melting and milling uranium metal at the Melt Plant Building at Hanford. The 

report describes in detail each step in the handling and processing of uranium rods and provides 

extensive data on airborne uranium particle/aerosol/fume loading, uranium particle size 

distributions, and the chemical form of the airborne uranium associated with each type of 

activity. The data presented in the report were gathered from February 1947 to May 1951. As 

such, the report may be considered a bounding surrogate for the machining of thorium during the 

early years of the practice. 

The Adley report divides the uranium operations it investigated into the following activities: 

• 14 steps associated with the remelt and recovery of uranium turning and chips that were 

generated during uranium machining operations 

• 6 steps associated with uranium rod straightening operations 

• 2 steps associated with uranium autoclaving 

The report provides a description of each of these 22 steps, along with a complete 

characterization of the aerosols produced at each step. Many of the steps can be considered 

applicable, if not bounding, for thorium machining operations that may have taken place at RFP. 

The first item would likely be the most applicable to RFP. 

The Adley report presents a detailed description of the methods used to collect and characterize 

the aerosols associated with each operation. High-volume air samplers (70 to 100 ft3

/min) were 

used to collect the samples on pleated filters with a filtering area of 73 in2. Most air samples 

were collected at breathing level near the various processes, and some were obtained as close as 

possible to the points where dust and fume originated. Particle sizes were determined using 

cascade impactors as well as a thermal precipitator, which deposited particles on glass slides 

where they could be viewed and measured. The former was used to determine the mass median 

diameter and the mass distribution, while the latter was used to determine the count median 

diameter and number distribution. 

Table 6-5 presents the results of multiple individual measurements taken at locations that appear 

to be particularly applicable to machining operations. It shows values that were copied directly 

from portions of Table II in the appendix to the Adley report. The table provides an indication of 

the variability of the airborne uranium concentrations associated with a given operation. 

These uranium data can be treated as equivalent in mass concentration terms to those of thorium 

(which would be claimant favorable). In turn, these can be converted into intake estimates for 

Th-232. It is claimant favorable and reasonable to assume Th-232 in equilibrium with its decay 

products. 
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Table 6-5. Summary of Selected Measurements Made at the Hanford Melt Plant 

Building Investigations 

Operat

ion Suboperation 

Results of Multiple Samples Taken from Different 

Locations/Suboperations within the Facility 

(10-5 micrograms U per cc of air) 

Saw Room 

Operations 

Stripping molds from 

billets 22 0.9 15 43 

Sawing billets 87 92 12 59 286 154 122 

Lathing billets 442 27 4.3 97 20 

Grinding 23,800 55 

Sweeping floor 86 

Miscellaneous 5.3 0.4 127 10 18 

Rod-handling 

Operations 

Unloading rods from 

freight cars 39 258 15 60 

Storage bay activities 258 34 5.8 43 65 2.4 277 28 51 

Nonproduction 

Areas Office 0.5 1.5 

Counting room 0.3 1.1 

Toilet 4.2 8.7 

Smoking room 2.3 1.2 3.5 

Source: Adley et al. 1952 

The Harris and Kingsley Report 

The Harris and Kingsley (1959) report also provides a comprehensive review of exposures 

associated with uranium operations, including (1) rolling, (2) forging either by means of hammer 

or a press, (3) extrusion, (4) drawing, (5) swaging, (6) machining, and (7) powder pressing. 

These operations are capable of releasing large quantities of uranium oxide dust to the air. The 

dust loading associated with many of these operations, especially machining operations, may be 

considered applicable, if not bounding, for thorium machining operations that might have taken 

place at RFP. Data from these investigations that appear to be relevant include milling, grinding, 

belt sanding, planning, and drilling. Table 6-6 shows air concentrations during certain 

operations. This table was the basis for NIOSH’s comparison of NUREG-1400 with machining 

and grinding operations, discussed above. 
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Table 6-6. Abrasive Operations (daily averages d/m/m3) 

Operator No Ventilation Ventilation 

Cutoff --* <1 

Surface grinder 2000–5000 50–200 

Portable grinder 400 50–200 

Belt sander 3000 <10 

Centerless grinder 5000–6000 50–300 

* Never sampled, but very high. 

 Source: Table 6 of Harris and Kingsley 1959 

Comparing the Data and Developing a Bounding Value 

The data from the various operations above need to be evaluated in the context of the RFP 

situation, notably with regard to the time during which the operations were carried out. NIOSH 

used the Harris and Kingsley data in this way in its December 21, 2006, report (Attachment 20), 

but opted to continue using NUREG-1400 rather than choose a bounding value based on 

measurements such as the ones above. 

With operational data such as those cited above, NIOSH should be able to develop a bounding 

value for thorium intakes during operations involving material from Oak Ridge. These data are 

also useful in evaluating the adequacy of the air concentration data during the various 1960 

operations involving ingots. SC&A’s analysis of welding fumes in the context of the Bethlehem 

Steel site profile review would be useful for the thorium flame-cutting operation in September 

1960. 

The issue of which workers were exposed to thorium in the course of machining of the parts 

from Oak Ridge would need to be addressed unless a dose is assigned to all workers in the 

associated buildings and periods.

6.3.2.4 Intakes from Other Thorium-232 Operations 

RFP conducted other thorium operations as well. Some of these involved less that 500 g of 

material; these were regarded as small and were not reported in materials accounting records. 

Such uses of less than 500 g included (Bistline 1976, p. 1 and pp. 3–4) the following: 

For coating molds with thorium oxide 

in analytical procedures and development programs (“probably” on numerous occasions) 

“as a stand-in or replacements for the more expensive Uranium or Plutonium components in 

certain phases of development programs. Usually these needs involved small amounts of 

material, but it nevertheless involved handling Thorium. This type of operation occurred 

frequently in the past and is occurring at the present time. Each individual use is too small for 

record keeping but, in the aggregate, it would approach 7 kg of Thorium in a variety of forms at 

the present moment” 
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The phrase “in the aggregate” in the last bullet appears to refer to all then-current thorium 

development programs during 1976; however, SC&A notes that the statement is ambiguous and 

may refer to a cumulative amount of thorium use in development applications. 

NIOSH implicitly proposed to use NUREG-1400 for these small uses as well. In its October 

2006 paper (Attachment 19, as quoted below) on thorium intakes, NIOSH stated the following: 

Other uses and operations involving thorium at RFP are listed in Table 1. The highest calculated 

potential internal intakes result from the fabrication of large metal weapons parts for which 

intakes are estimated above. Smaller quantities assumed for most of the other uses and 

operations are offset by the thorium being in the form of powders or other more dispersible 

materials, but still resulting in fractional mrem estimated doses. [Attachment 19, p.5]

However, the argument that doses would be in the “fractional mrem” has not been well 

established. The source term for these small uses is not individually documented in material 

control records due to the then-prevailing policy regarding thorium accounts. The higher DCFs 

for thorium for some organs make one gram of Th-232 radiologically comparable to a far larger 

amount of uranium (in the worst case, approximately 100 times larger for bone surface dose for 

the same solubility, using DCFs for committed dose in Federal Guidance Report 13 (EPA 1999) 

as the basis for the comparison). Hence, small amounts of Th-232 would represent doses that 

would correspond to those delivered by much larger amounts of uranium for bone surface and 

several other organs. 

NIOSH’s attempt at validating the use of NUREG-1400 does not meet the criteria of 42 CFR 

Part 83, as discussed above. The most recent validation attempts using weighted average air 

concentration data from Simonds and one air sample from RFP may provide a starting point for a 

use of NUREG-1400 at RFP for small sources, but a convincing demonstration has not yet been 

made. It may be possible to choose a single value of air concentration from among the extensive 

data on air concentrations for various operations that would bound all RFP small operations. 

It is likely that a suitable approach for small uses of Th-232 (i.e., those each less than 500 g) can 

be developed, but this has not yet been done. 

The issue of which workers were exposed to thorium in small amounts would need to be 

addressed unless a dose is assigned to all workers in the associated buildings and periods. 

6.4 URANIUM-233 AND THORIUM STRIKES ON URANIUM-233 

RFP processed U-233 between 1965 and 1983. The U-233 contained, among other things, up to 

50 ppm of U-232. It was processed in the 700-series buildings (771, 774, 777, 777A, 779A), 

where plutonium was also processed, Building 559 (assay lab), and Buildings 881 and 883 at 

various times during this period, (ICF 1999). 

RFP bioassay results for uranium were in disintegrations per minute (dpm) rather than in terms 

of weight. Uranium bioassay data are available, and nothing indicates that U-233 operations 
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were omitted from surveillance that was exercised for less radioactive forms of uranium. SC&A 

concludes that it should be feasible to estimate U-233 intakes. 

The problem regarding Th-228 contamination of U-233, which arose from the presence of traces 

of U-232 (50 ppm) in the U-233, is more complex. RFP conducted operations to remove the 

Th-228 from U-233 prior to processing the latter according to customer requirements. NIOSH 

proposed to use NUREG-1400 to provide an upper bound estimate for intakes of Th-228 during 

such operations. Its evaluation of the matter in its December 21, 2006, report stated the 

following: 

The previous comparison between conservative values above resulted in a value above the 

NUREG-1400 estimate. In this case, the Th228 extraction with daughters is so grossly 

overestimated both in terms of total quantity of isotope present and in the demonstrated 

confinement of the glove box process facilities in which the extraction and waste handling was 

performed, that the NUREG-1400 estimate is not deemed overly conservative. Air activity that 

would result in 100 Bq intake would have been cause for a significant release with the 

subsequent detail in the health physics logs we have reviewed. [Attachment 20, p. 13] 

SC&A found the proposed use of NUREG-1400, with an ad hoc reduction in the confinement 

factor from 0.01 recommended in that document to 3.4E-4, unpersuasive in light of the failure to 

demonstrate that NUREG-1400 produced bounding doses in the other applications and the gap of 

two orders of magnitude between the 1 Bq intake estimate and the alarm set point. NIOSH 

further explained the situation in its February 2007 report as follows: 

The discussion regarding a 100 Bq release was simply to bolster the case for NIOSH using a 

confinement factor of 3E-4 for the Rocky Flats high integrity gloveboxes, rather than the 0.01 

default in NUREG-1400. Had the default confinement factor been used instead of the more 

realistic but still conservative value used by NIOSH, the resulting predicted air concentrations 

would have been high enough to alarm the CAMs in Building 771. It must be emphasized that 

this was but one supporting argument for this confinement factor. The most compelling 

argument is that the gloveboxes were equipped with two in-line high efficiency HEPA filters, 

and no accident conditions (e.g., glove punctures, seal failures, etc.) were noted in the 

documentation describing the thorium strikes. Under normal operating conditions, such as those 

during the thorium strikes, the value of 3E-4 for the confinement factor for the high integrity 

gloveboxes is justified. The estimate of 1 Bq was based on NUREG-1400 calculations, not on 

the argument that a 100 Bq release was not possible. [Attachment 23, Issue 34] 

SC&A’s main concern regarding this issue is not the adequacy of glovebox confinement, but the 

use of NUREG-1400 for RFP. Air monitoring data in the workplace with functioning 

gloveboxes at RFP are likely to be plentiful enough to demonstrate that a particular number for 

intake estimate is reasonably bounding. Yet NIOSH has not attempted to use any onsite air 

monitoring data but resorted to NUREG-1400, with an ad hoc confinement factor applied as 

well. 
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SC&A continues to have reservations about the use of NUREG-1400 instead of onsite data for 

air concentrations in areas where comparable gloveboxes were used. Since the source terms are 

known with reasonable accuracy, NIOSH should be able to establish an intake based on air 

concentration data for other elements, such as Pu-239, and measured confinement factors. 

SC&A Evaluation: 

In terms of dose estimation methods, NIOSH’s analysis has established the plausibility of using 

NUREG-1400 to provide a general view of average working conditions. However, 

notwithstanding the availability of alternative methods, the examples provided to date have not 

validated the use of NUREG-1400 in estimating a plausible upper-bound dose for individual 

workers at RFP that would meet the criteria of 42 CFR Part 83. While alternative approaches 

have been discussed within the working group, NIOSH continues to believe NUREG-1400 is 

valid for application under the specific conditions applying to RFP. As a result, the thorium 

dose reconstruction matter remains open as an SEC issue.

6.5 REMAINING RADIONUCLIDES 

The other radionuclides that SC&A raised in the context of the TBD review matrix or that 

NIOSH has mentioned in the TBD are Cm-244 and Np-237. These appear to have been used at 

RFP as tracers and mixed with plutonium. SC&A had also raised the question of the availability 

of tritium bioassay data. The bioassay data in the HIS-20 database do not represent any of these 

radionuclides. 

In its November 3, 2006, report (Attachment 22), NIOSH agreed that the HIS-20 database does 

not represent these three radionuclides. Instead, NIOSH provided references to Cm-244 bioassay 

data and other documentation. Special bioassay results are also available for Np-237. NIOSH 

also stated that tritium bioassay results are available in claimant files. 

SC&A Evaluation: 

In view of the availability of bioassay data, SC&A concurs with NIOSH that estimation of Cm244, Np-237, and tritium intakes is not an SEC issue. 

6.6 REVIEW OF THREE HYPOTHETICAL INTERNAL DOSIMETRY DOSE 

RECONSTRUCTION CASES 

NIOSH provided SC&A with three hypothetical dose reconstruction cases for review of 

procedures and methods used to assign doses, three of them related to internal contamination 

(Cases 4, 5, and 6). SC&A analyzed these three examples to determine if the dose 

reconstructions were consistent with present guidelines and recommended procedures, and if 

procedures allow for claimant-favorable dose reconstruction. 
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6.6.1 Case 4—Hypothetical Coworker Assignment for Unmonitored Uranium Worker 

This case provided an example of a hypothetical worker, potentially exposed to uranium, who 

worked at RFP from 1956 through 1966. This worker was monitored from 1960 through 1966. 

All measurement results were below detection limits. The worker had a potential for uranium 

exposure from 1956 through 1959, but was not monitored during this time. NIOSH calculated 

the uranium exposure of this worker, based on coworker data for the period 1956 through 1959 

and on the bioassay detection limit for the period 1960 through 1966. For the missed dose, a 

chronic intake rate was assumed using half the MDA for that radionuclide and assigned as the 

mode dose, with the maximum dose being twice the mode dose. 

SC&A Evaluation: While NIOSH was able to provide an adequate dose reconstruction for this 

case, SC&A identified several areas of concern: 

. 

The worker had a potential for uranium exposure from 1956 through 1959, but he was not 

monitored. The dose for this period was based on a coworker model that used the 50th percentile 

to calculate the intake. As a result, the calculated intake rate corresponded to less than half of the 

theoretical reporting level for uranium in urine. This would not be claimant favorable. 

For the period of 1960 through 1966, NIOSH calculated the missed dose using one-half the 

MDA for the median conditions. In the occupational internal dose TBD (ORAUT-TKBS-0011-

5) (Falk 2004), the MDAs for the median and extreme conditions were calculated for the period 

1952 through 1971, based on results from the logs. Variations on the number of extreme 

conditions produced different values of MDA. For uranium, there is about five-fold difference 

between the MDA for the median and extreme conditions. Under these circumstances, SC&A 

questions the validity of assigning missed doses based on half the MDA for the median 

conditions. 

 

6.6.2 Case 5—Hypothetical Assignment for Ingestion of Depleted Uranium 

This case provided an example of a hypothetical worker, potentially exposed to uranium, who 

worked from 1966 through 1969. In a hypothetical incident, the worker ingested DU and had 

reported positive urinalysis bioassay data. The energy employee worked as a radiation monitor. 

His primary exposure would have been to DU. His records show that urinalysis bioassay 

monitoring was conducted three times per year, with no positive results except for one 

measurement result that showed an activity above the level of detection 5 days after the ingestion 

incident. No in-vivo monitoring results were available. The worker’s primary cancer organ was 

the colon. 

SC&A Evaluation: SC&A reviewed the procedures followed by NIOSH to calculate the intake 

and dose for the hypothetical incident where a worker ingested DU and had a reported positive 

urinalysis bioassay data 5 days after the ingestion. In addition, SC&A recalculated the intake 

and doses due to this hypothetical incident, using alternative software to IMBA. SC&A has 

concluded that the intake and dose calculated by NIOSH are correct for a single intake associated 

with an ingestion exposure. 
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However, SC&A does not necessarily agree with the exposure scenario attributed to this worker. 

NIOSH has considered that all other monitoring results, recorded as zero (below detection 

limits), were associated with zero exposures. SC&A considers this approach not claimant 

favorable. In Case 4, a missed dose based on the MDA was calculated for all monitoring results 

below detection limits. In this example, calculation of the missed dose using continuous intake 

by inhalation gives an additional dose to the colon one order of magnitude higher then the 

accidental ingestion intake. NIOSH did not consider the missed dose in this case. 

The exposure scenario used by NIOSH is not claimant favorable. Missed dose associated with 

continuous exposure through inhalation should have been calculated, with an additional ingestion 

exposure. In general, NIOSH uses the hypothesis of a continuous intake to calculate missed 

doses. NIOSH should provide a clear definition for the benefit of the dose reconstructor to avoid 

different procedures applied in similar cases, as occurred in Cases 4 and 5. 

6.6.3 Case 6—Hypothetical Type Super S Material Assignment for Monitored Plutonium 

Worker with No Chest Counts and Positive Urinalysis Results 

This case provided an example of a hypothetical individual who worked from 1961 through 1969 

in RFP Buildings 771, 776, and 707 and was exposed to fresh plutonium (100 ppm Am-241). 

The worker had three positive urinalysis results, two consecutive results in 1963 and one in 

1964. No in-vivo monitoring data were available. The OCAS white paper, Approach to Dose 

Reconstruction for Super Type S Material (March 21, 2006) (NIOSH 2006o), was applied to four 

scenarios—lung cancer, GI tract cancer (colon), systemic metabolic cancer (liver), and systemic 

nonmetabolic cancer (prostate). The OCAS white paper from March 21, 2006, is now an integral 

part of ORAUT-OTIB-0049 (ORAUT 2007b). 

SC&A Evaluation: SC&A reviewed the procedures followed by NIOSH to calculate the intake 

and dose for the four cancer hypothetical scenarios. NIOSH assigned to the worker an acute 

intake on May 6, 1963, and a chronic intake from August 13, 1964, to September 24, 1964. The 

intake rates for the various radionuclide components (Pu-238, Pu-239, Pu-241, and Am-241) 

were based on the plutonium mixture of fresh weapons-grade plutonium (100 ppm Am-241). 

SC&A reviewed the procedures followed by NIOSH to calculate the intakes and doses for the 

hypothetical worker. In addition, SC&A recalculated the intakes and doses using alternative 

software to IMBA. 

SC&A has concluded that the intakes and doses calculated by NIOSH are correct, for the 

hypothetical scenario used by NIOSH and Type S, activity medium aerodynamic diameter 

(AMAD) 5 μm, plutonium intakes. The intakes of the various radionuclide components were 

also correctly calculated. 

The use of a continuous chronic intake from August 13, 1964, to September 24, 1964, produces 

lower intakes and doses than if a single intake in the middle of the monitoring interval was 

assumed. 
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6.6.4 Summary of Dose Reconstruction Cases 

SC&A derived the concerns described above from its analysis of the three hypothetical dose 

reconstruction cases to determine if the procedures were claimant favorable and reasonable. The 

results reflect some of the same issues identified by SC&A in the RFP site reviews for actual 

workers. A detailed report of this evaluation is provided in Attachment 25. These concerns are 

most likely not SEC issues, but they need to be addressed in terms of the site profile to ensure 

claimant favorability 

6.7 DATA SUFFICIENCY AND APPLICATION OF THE INTERNAL DOSE 

COWORKER MODEL 

Issues regarding the derivation and application of ORAUT-OTIB-0038, Rocky Flats Plant 

Internal Co-worker Model (Arno et al. 2006), were raised upon its issuance and discussed at the 

August 31, 2006, Advisory Board working group meeting. These issues revolved around the 

following:7

• Median MDA versus extreme condition MDA versus reporting levels: 

SC&A had determined that a large percentage of bioassay results for plutonium from 

1953–1966 were below the reporting level. Median MDAs after 1962 were higher than 

the reporting level. SC&A questioned how meaningful results below the MDAs were 

and how data below these thresholds should be applied in the coworker model. 

• The application of a linear distribution to results below reporting levels: 

NIOSH’s approach of substituting a linear distribution between zero and the reporting 

level for the zeros is justified in ORAUT-OTIB-0038: 

Furthermore, the linear distribution has an average equal to half of the 

reporting value, consistent with the general dose reconstruction practice of 

assigning half of the lower limit of detection for missed dose calculations. 

Consequently, substituting a linear distribution for these zero entries appears 

reasonable. (Arno et al. 2006) 

SC&A believed that the basis for this assumption was not clear. The reporting level is not a 

lower limit of detection. The reporting level is a nonparametric value, unrelated to the real 

capacity of distinguishing between real measurement results and background or noise counts. 

Half the reporting level is not a statistically meaningful value and can not be used to justify a 

procedure. 

7

 As categorized in an October 31, 2006, e-mail from D. Allen, NIOSH. 
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• Whether monitored individuals represent those with the highest exposure potential:

SC&A questioned the NIOSH evaluation report conclusion that “in general, participation 

in a bioassay program involves workers who have the largest potential for exposure” and 

that “....it is unlikely that an unmonitored worker would have received a larger dose than 

the most highly exposed monitored worker at a site” (NIOSH 2006a). SC&A was 

concerned with how the coworker model could be derived without establishing the 

number of workers in specific work locations and the number monitored in each area. 

SC&A also questioned how an assumed lognormal distribution could be fitted to the 

available data without knowing statistically whether the sampled worker population was 

representative of the target population of interest. 

In response to these and other issues raised, NIOSH developed its White Paper—Rocky Flats 

Plant Internal Co-worker OTIB for further discussion and issue resolution (provided in 

Attachment 26). The white paper, authored by D. Allen of NIOSH, addressed four topical issues 

(Allen 2006a): 

(1) Z-score plot approach to determining distribution parameters 

(2) Censored data handling 

(3) Why MDA does not matter 

(4) Linear substitution approach to censored data 

SC&A provided feedback to NIOSH on the white paper. In general, SC&A accepted NIOSH’s 

explanation for how the Z-score plot was obtained and the censored data were handled but 

continued to raise questions regarding the reliability of the measurement results in relation to the 

MDA. With respect to the linear substitution approach, SC&A did not agree with the basis 

described for its adoption. In particular, SC&A found the following: 

The reporting level is not a lower limit of detection. Actually it is below the 

median MDA and thus it is a value of doubtful meaning in terms of measurement 

of real activity. The assignment of half of the lower detection limit (half the 

MDA) is also not scientifically justifiable. The lower limit of detection (MDA) for 

urine analysis is not a unique value. It will generally vary from sample to sample. 

The calculation of each sample MDA is based on a normal distribution of 

activities. The median MDA for all samples is a non parametric value, and thus 

half the median detection limit (half the MDA) does not have any statistical 

meaning. In the same way the reporting level is a non parametric value, 

unrelated to the real capacity of distinguishing between real measurement results 

and background or noise counts. In the same way half the reporting level is not a 

scientifically statistically meaningful value and cannot be used to justify a 

procedure. [Lipzstein 2006]

In response, D. Allen of NIOSH observed that ORAUT-OTIB-0038 “stops at a point that a 

distribution of monitored workers is defined...how that distribution is used is outside of the scope 

of the OTIB” (Allen 2006a). SC&A agreed that the application of the TIB, as opposed to the 
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TIB itself, is the more relevant SEC issue, and an issue-specific conference call was scheduled 

for December 6, 2006, to address the three remaining issues originally categorized by NIOSH. 

The minutes of this discussion are provided in Attachment 26. 

In summary, NIOSH noted that it intended to apply the 95th percentile distribution for 

unmonitored workers and that this approach was deemed sufficiently claimant favorable based 

on experience at Bethlehem Steel and other sites. SC&A questioned whether this was 

sufficiently conservative based on what were apparently data points higher than those 

encompassed by the 95th percentile distribution (i.e., why not higher percentile distributions such 

as 99th). It was pointed out during the discussion that the RFP dose file had been updated and 

some of these higher dose values may have been dropped out (because they were linked to 

isolated incidents and therefore not representative). Additional discussion is needed regarding 

the representativeness of the database (inclusive of the likely most exposed workers) and its 

completeness. HIS-20 versus the CEDR initially resolved those issues to the satisfaction of the 

working group. However, it became clear from later working group interchanges with NIOSH 

that the median (50th percentile) of the full distribution of internal dose values is actually being 

applied in the dose reconstructions being performed. While the conservatism of the coworker 

model has been characterized in working group discussions as an issue related to the site profile 

and not the SEC, SC&A believes that applying a nonconservative statistical fit to the dose 

distribution derived from the coworker model can undercut the scientific validity of how the 

model, itself, is used. 

6.7.1 SC&A Technical Analysis of ORAUT-OTIB-0038 

At the request of the Advisory Board working group, SC&A evaluated the internal coworker 

model and its application. As noted above, it was agreed that the SEC-related issues pertained 

more to the application of ORAUT-OTIB-0038 in terms of the statistical dose distribution used 

and to the completeness of the HIS-20 database itself, upon which the approach is derived. 

6.7.1.1 SC&A Observations on the Interpretation of Zero Monitoring Results, Low Value 

Monitoring Results, and Reporting Levels 

SC&A finds that the application of the linear distribution provided for use in ORAUT-OTIB0038 as a substitution for low internal dose value results does not have a clear scientific basis. 

SC&A notes that such a linear distribution was not used for plutonium. For plutonium, NIOSH 

has used the exact values as they were reported in the dose files and has substituted the zeros by 

the reporting level of 0.88 dpm/24 hours. While the TIB ranks the 0.88 values, it does not use 

those values to fit the lognormal distribution. SC&A believes there is no clear scientific 

rationale to accept that the registered values lower than 0.88 dpm/24 hours are real 

measurements and that the zeros are equal to 0.88 dpm/24 hours. In ORAUT-OTIB-0038, the 

intake is derived based on the 50th percentile of a lognormal fit to the bioassay results in a certain 

period of time (year or quarter of a year). A large fraction of the registered bioassay values are 

equal to zero. Thus, the 50th percentile depends on the approach NIOSH uses to account for the 

zero values, low bioassay results, and below reporting-level values. 
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SC&A notes that the MDA for median conditions was higher than the reporting levels for some 

of the years for which internal dose data are provided. The MDAs for the median and extreme 

conditions were calculated for the period 1952–1971 and are presented in ORAUT-TKBS-0011-

5 (Falk 2004). The MDA was not discussed in ORAUT-OTIB-0038, and neither of the MDA 

values was applied to workers with zero or low monitoring results or discussed in relation to 

reporting levels. SC&A finds that uncertainties in the MDA values bring great uncertainty to a 

model based on low monitoring excretion values. 

Further, the MDA for plutonium is assessed for the median and the extreme condition for the 

blank, the recovery, the volume factor, and the alpha transmission factor individually and in 

combination in ORAUT-TKBS-0011-5 (Falk 2004). There is as much as a nine-fold difference 

between the MDA for the median conditions and the extreme conditions for plutonium for the 

years 1952–1971. This introduces considerable uncertainty given the relatively low internal dose 

values reported at RFP and, consequently, to the coworker model based on those low values.

6.7.1.2 SC&A Observations on the Appropriate Statistical Distribution to Represent the 

Unmonitored Worker 

As noted in ORAUT-OTIB-0038, “Statistical methods used to calculate co-worker intake values 

assume that bioassay results for group of workers have a lognormal distribution” [emphasis 

added]. Even accepting this statistical distribution, it is not known how to place the unmonitored 

worker in the group. If the physical samples represent a statistical sample from a population to 

be characterized, it is important to know the statistical design (or lack thereof) of the procedure 

used to select the samples. The design of the sampling procedure should be considered before 

using the data to estimate characteristics of a target population from which the sampled 

individuals were selected. In sample design, all members of the population must have a known 

(nonzero) probability of selection into the sample before the results can be considered as 

representative of the population. This simple requirement defines the population that the 

samples represent. Using the estimated distribution to represent workers with unknown or zero 

probability of selection into the sample is a subjective decision, not a statistical one, and should 

be identified as such. In short, a database full of numbers cannot be used as a representative 

statistical sample unless the probability of selection is known for all members of the target 

population, both selected and unselected. 

6.7.1.3 SC&A Concerns Regarding the Potential for Internal Exposure of the Unmonitored 

Worker 

NIOSH has hypothesized that unmonitored workers received a lower dose than the highest 

exposures documented for monitored workers. In the SEC petition evaluation report (NIOSH 

2006a), it is explained that “in general, participation in a bioassay program involves workers 

who have the largest potential for exposure” and that “... it is unlikely that an unmonitored 

worker would have received a larger dose than the most highly exposed monitored worker 

at a site” [emphasis added]. However, NIOSH provides no statistical or quantitative technical 

basis for this hypothesis. It is quite possible, in the early years when monitoring protocols were 
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still being developed, that some groups of unmonitored workers might have exposures that could 

have exceeded the exposures of monitored workers. 

An example taken from SC&A’s evaluation of RFP external dose assessment history illustrates 

this point. For neutron exposure, workers in Building 71 were not monitored at all until 1958, 

even though they were among the employees at highest risk for such exposure. In this case, such 

a hypothesis that the highest exposed workers were monitored would be incorrect based on 

actual historic circumstances. Likewise, it is essential for NIOSH to demonstrate that its 

hypothesis that “participation in a bioassay program involves workers who have the largest 

potential for exposure” is, in fact, a correct one for internal dose. A number of means are 

available for such validation, some of which have been used in the past at other DOE sites. For 

instance, monitored and unmonitored workers can be compared by job types, radionuclide 

exposure lists, and contaminant air concentrations. Such comparisons would provide a means 

for NIOSH to test its hypothesis and demonstrate that the worst-case conditions of exposure of 

unmonitored workers were such that the highest monitored worker measurements would envelop 

them. 

The logbooks from early RFP operations contain some discussions on who should be monitored 

and which tasks needed monitoring. Thus, it is possible that some workers who were not 

monitored received high doses and that some practices were only monitored after having been 

implemented for some time. The example below, from a meeting held in September 1958 

extracted from a logbook from 1957–1960, illustrates this fact [Kittinger personal log 10-1-57– 

8-26-60]: 

I took position that contamination is not under control in either B1 or B3; cold 

areas are being contaminated, personnel are easily able to carry contam. Home, 

and N.P. checks being by-passed. I further took the position that supervision in 

both Bldgs have shown lack of appreciation of control techniques. 

The fact that some of the workers who were monitored presented high excretion rates puzzled 

the radiation protection staff. Thus, some jobs that might have presented radiation contamination 

risks might have been misjudged and workers might not have been monitored, as may be inferred 

from the following example, from a discussion on high urinalysis results, in September 1959: 

xxxxx, xxxxx, xxxxx & I had conference yesterday concerning the high urine 

counts. They have investigated and find no reason. 

The NIOSH data integrity examples (NIOSH 2006j) contain several examples of worker 

concerns, which raised questions regarding the inclusiveness of the bioassay program in relation 

to internally exposed workers: 

• In the Molten Salts Building (776), a hole had developed in both walls in the double-lined 

furnace (double lined). The furnace was loaded, heated, and overpressurized, causing it 

to vent to the atmosphere in the room. Personnel were without respiratory protection at 

the time. No bioassays were taken. 
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• Furtive job tasks were conducted outside of normal work controls without airborne 

contamination monitoring or personnel monitoring. For example, an RCT became highly 

contaminated, but because the work evolution was not documented, no nasal smears or 

bioassay samples were taken. This practice was more common than not. 

• Many times contamination was washed off without being reported. 

• In one case, an energy employee did not have a first urinalysis sample available until 

1975, although he worked in hot areas for at least 3 years. Given the lack of safety 

protocol in the early years, some kind of reading should exist. However, only zeroes are 

recorded, including for those years when the energy employee was a clerk packer. 

• An employee served as a machinist during the 1970 strike with a gap in his bioassay data 

from 1967–1972. The health physics file contains no indication of a work restriction, and 

according to the CATI he was involved in incidents in 1961 and 1969. According to his 

CATI interview, he was given beer when working in Building 881 and asked to finish it 

within 12 hours. This approach is commonly used to clear highly soluble radionuclides, 

such as Type F uranium or tritium, from the system. His dose file contained no bioassay 

data for tritium. 

• No bioassay was performed on a man whose mask was so contaminated it had to be 

shipped as high-level waste. 

 

6.7.1.4 SC&A Concerns Regarding Unrecognized Exposures to High-fired Plutonium 

Oxides, for which the Bioassays Would Not Detect the Deposited Material 

There were numerous fires, large and small, at the RFP plant over its history, many of which 

apparently occurred without record or notification to the fire department or management. Such 

fires involved high-fired plutonium oxide (Type SS), which has been shown to exhibit long-term 

retention in the lung exceeding that predicted by the standard Type S model. One of the major 

fires at the plant occurred in Building 71 in 1957, and numerous worker may have experienced 

some intake during, after, or even months or years after the event and may have terminated their 

employment or died prior to any bioassay sampling. One notable case from the 1957 fire 

involved a worker who had only one or two urine samples taken after the event, and no fecal 

analysis performed then or at work termination several years later. The urine samples showed 

nothing. The worker was found in the RFP recall followup, around 40 years later (when the 

employee was 90 years old), to have one of the largest lung depositions of plutonium ever 

recorded at RFP. 

 

Given the very low solubility of high-fired or Type SS plutonium oxide, the workers involved in 

such fires would likely either contribute to the zero entries in urine bioassay or would not have 

been monitored further because their earlier bioassay samples were below detection limits. 

There is no referencing to ORAUT-OTIB-0049 (ORAUT 2007b) in ORAUT-OTIB-0038 

models. ORAUT-OTIB-0049, on the other hand, mentions that the methods described in this 

TIB can be applied to doses from coworker studies for sites where Type SS absorption is 
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appropriate, but only Type S intakes were assessed. In contrast, ORAUT-OTIB-0038 calculates 

plutonium intakes as either Type M or Type S, with no mention of unmonitored worker exposure 

to high-fired nuclides.(presumably, ORAUT-OTIB-0049 would take precedence, although 

ORAUT-OTIB-0049 can only be applied if the worker had a known exposure to high-fired 

plutonium oxides); NIOSH should clarify how potential exposures of unmonitored workers to 

high-fired plutonium will be addressed from the coworker standpoint, given that workers may 

have been exposed during these unreported small fires or could have been exposed to high-fired 

oxides or residues during D&D and other activities without knowing that they were exposed to 

high-fired plutonium oxides.

 

6.7.1.5 SC&A Observations Regarding the Treatment of High Excretion Rates 

A coworker model needs to distinguish whether high excretion cases were routine samples, 

samples related to incidents, or samples following chelation. This is a significant set of variables 

that pose a considerable technical challenge for suitable integration into a coworker model. 

Without a detailed explanation, NIOSH has excluded the highest excretion data from the data file 

that provided the basis for deriving the ORAUT-OTIB-0038 model. The Lochamy paper from 

April 6, 2006 (Lochamy 2006), shows CEDR values in 1964 and 1965 that differ from the ones 

in the RFETS plutonium file used to generate intake and doses for the ORAUT-OTIB-0038 

model. In the RFETS tables, the GM for 1964 is cited as 0.321, and the geometric standard 

deviation (GSD) is given as 0.996, compared to 0.508 and 3.64, respectively, in the Lochamy 

table. The Lochamy table gives the number of samples in 1964 for CEDR as 4,976, with a 

maximum value of 1,800,000 dpm/24 hr, while the RFETS tables for plutonium, used to generate 

the TIB model, gives it as 4,761 samples, with a maximum value of 2,290 dpm/24h. 

In the 1965 RFETS table, the GM for 1965 is 0.227, and the GSD is 0.70, as compared to 0.474 

and 2.279, respectively, in the Lochamy table. In the Lochamy table, the number of samples in 

1965 for CEDR is 5,168 with a maximum value of 173,000 dpm/24 hr, while the RFETS table 

for plutonium, used to generate the TIB model, cited 4,900 samples, with the same maximum 

value of 173,000 dpm/24h. Thus, using the same CEDR database, but apparently excluding 

different samples and values, the Lochamy table and the RFETS tables used to derive the 

ORAUT-OTIB-0038 model give different results. NIOSH has not yet provided a definitive 

explanation for these differences. 

SC&A is concerned that the coworker model does not represent the distribution of values to 

which the overall set belongs. If data from an incident are excluded without known and wellestablished criteria, then the distribution that remains without the missing data may not be the 

correct one since the right (high-end) tail of the distribution will be too thin without those values. 

6.7.1.6 SC&A Remarks on the Significance of the Intake Rate Derived in ORAUT-OTIB0038 in Relation to the Excretion Rate 

When NIOSH derived the ORAUT-OTIB-0038 intake model based on coworker monitoring 

data, two sequential fitting approaches were used to interpret the bioassay data. The first one 
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grouped the bioassay monitoring data by time, and a lognormal distribution was assumed as the 

best representation of all the RFP worker bioassay results during a certain period of time. The 

GM and the geometric standard deviation were derived for each time period. The second 

approach consisted of the derivation of an inhalation intake function that would reproduce the 

GM bioassay values that were calculated using the first approach. 

 

Approach 1: A lognormal distribution was assumed for the bioassay data, which were analyzed 

by quarter or year, depending on the amount of data available during the periods. The fitting of 

the data to a lognormal distribution was statistically acceptable, but many times did not represent 

well the data at the high end of the results. The acceptance of the lognormal distribution, 

employing the methodology used in ORAUT-OTIB-0038, deserves some discussion in terms of 

how well the distribution represents the bioassay results, taking into consideration the significant 

percentage of values that do not fit the lognormal distribution in relation to the number of 

positive bioassay results. The discrepancies between the high “real” results and the ones 

generated by the curve are significant. Depending on the year, these discrepancies may start at 

the 95th percentile level, as in 1958 (when, for example, in the first quarter, the 95th percentile 

calculated by the equation was 27.16 and the result that occupies rank 95 is 55.3), or at a higher 

percentile as in 1966. Analysis of the RFETS table values for 1966, by quarters, provides the 

following results: 

• 1st Quarter: The 95th percentile as calculated by the lognormal regression equation is 

1.6 dpm/24h, and the 95th value (the result that occupies the rank 95, when results are 

placed in ascending order) is 1.63. The coefficient of determination (R2

) for the equation 

is 0.64, with larger discrepancies on the high end of the curve. There are 61 values that 

are higher than the 95th value, the largest one being 230 dpm/24h. There are 42 results at 

least 10 times higher than the 95th percentile. The 99th percentile as calculated by the 

equation is 3.23 dpm/24h, and the 99th value is 70 dpm/24h. 

• 2nd Quarter: The 95th percentile as calculated by the lognormal equation is 

0.96 dpm/24h, and the 95th value is 0.87. The R2 for the equation is 0.65, with larger 

discrepancies on the high end of the curve. There are 58 values that are higher than the 

95th value, the largest one being 140 dpm/24h. There are 24 results at least 10 times 

higher than the 95th percentile. The 99th percentile as calculated by the equation is 

1.7 dpm/24h, and the 99th value is 5.17 dpm/24h. 

• 3rd Quarter: The 95th percentile as calculated by the lognormal equation is 

0.67 dpm/24h, and the 95th value is 0.63. The R2 for the equation is 0.73, with larger 

discrepancies on the high end of the curve. There are 49 values that are higher than the 

95th value, the largest one being 110 dpm/24h. Seven results are at least 10 times higher 

than the 95th percentile. The 99th percentile as calculated by the equation is 1.1 dpm/24h, 

and the 99th value is 55 dpm/24h. 

• 4th Quarter: The 95th percentile as calculated by the lognormal equation is 

1.129 dpm/24h, and the 95th value is 0.95. The R2 for the equation is 0.68, with larger 

discrepancies on the high end of the curve. There are 56 values that are higher than the 
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95th value, the largest one being 160 dpm/24h. There are 23 results at least 10 times 

higher than the 95th percentile. The 99th percentile as calculated by the equation is 

2.09 dpm/24h, and the 99th value is 110 dpm/24h. 

NIOSH considered these high values as routine monitoring results. The ones related to accidents 

or incidents were excluded from the analysis. 

SC&A Evaluation: 

In conclusion, SC&A considers the lognormal distribution used by NIOSH in these applications 

not to be representative of the higher bioassay values. Essentially, the recorded high-end dose 

values are left out. Therefore, the uncertainties derived from the lognormal distribution are 

misleading since they do not adequately address the contribution of these higher internal dose 

results. In addition the value of the 50th percentile is an artificial number, not related to any 

measured value, and thus it is not to representive of the monitored worker excretion rate. 

Approach 2: The intake model was derived using an IMBA fit to several years of data. Intakes 

were not derived for each time period, when a GM would have been derived from the lognormal 

distribution representing that time period. Instead, an IMBA fit was derived for a period of 

several consecutive years. For Type M plutonium, for example, just one intake rate was 

considered for the period from 1952 to 1961. This intake rate theoretically produces excretion 

rates for 1952 to 1961, which can be represented by the solid line shown in the Figure 6.1, 

comparing the theoretical fit for Type M materials to the individual 50th percentile excretion 

rates (Arno et al. 2006). As can be observed, there are large discrepancies between the predicted 

bioassay results using the derived intake rates for the period (solid line) and the GM results for 

the different periods (blue dots). The red dots correspond to time periods after 1961. 

 

Figure 6-1. Predicted Plutonium Bioassay Results (line) Calculated Using IMBA-derived 

Pu Intake Rates Compared with Measured Pu-in-Urine Results (dots) 

(January 1, 1952, to December 31, 1961, 50th percentile, Type M) 

(Reproduced from ORAUT-OTIB-0038, Figure B-21, pg. 29)
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The model intake rates do not correspond to the 50th percentile of each period of time analyzed. 

As shown in the figure above, in some time periods, the dose will be calculated using an intake 

rate that corresponds to urinary excretion values smaller than the 50th percentile of the excretion 

rates of the workers for that time period. Using this same modeling approach, the dose 

calculation using of the 95th percentile would, for some time periods, correspond to urinary 

excretion rates well below the 95th percentile of the excretion rates of the workers. 

SC&A Evaluation: 

When NIOSH uses the 50th or 95th percentile intake rates, it should not be understood as the 50th

or 95th percentile of the workers intake rates, but to a model intake rate, with some periods of 

time when the urine excretion rates percentiles from the lognormal distribution will be 

underestimated and some periods of time when they will be overestimated. 

SC&A Conclusion:

SC&A considers the lognormal distribution used by NIOSH in these applications to misrepresent 

the higher bioassay values incurred by the workers during their routine work at RFP. In addition, 

SC&A considers the 50th percentile excretion rates from the lognormal distribution to be 

artificially derived, not corresponding to any measured intake rate, and not representative of the 

excretion rates of the monitored workers. The model intake rates from the IMBA fit will further 

underestimate the 50th percentile intake rates during certain periods of time. 

6.7.2 SC&A Analysis of the Database Used by NIOSH to Derive the Intake Model 

Described in ORAUT-OTIB-0038: Comparison of HIS-20 versus CEDR Databases 

ORAUT-OTIB-0038 was based on the CEDR database. NIOSH has investigated the differences 

between the CEDR and HIS-20 databases for RFP workers and has presented information to the 

working group in reports dated March 26, 2006 (Lochamy et al. 2006); April 6, 2006 (Lochamy 

2006); and October 2006 (Cragle 2006). NIOSH used these reports to demonstrate that there is 

good agreement in the parameter values calculated from either database and used for the 

generation of coworker data distributions. In those analyses, NIOSH has provided a comparison 

of the number of records in each database. 

The two Lochamy papers and the Cragle paper do not use exactly the same terminology. For 

example, the Lochamy paper presents the number of samples for a period of time. The Cragle 

paper presents the number of records for a certain period of time and the number of individuals 

who were monitored. When the number of records is compared to the number of samples 

analyzed in a certain period of time, the numbers do not match, as exemplified in Table 6-7: 
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Table 6-7. Comparison of the Number of Samples Reported by Lochamy with the 

Number of Records Reported by Cragle 

Database Years Lochamy Cragle 

CEDR 1973–77 29,559 39,779 

HIS-20 28,778 40,180 

CEDR 1978–82 32,407 35,789 

HIS-20 32,297 44,839 

CEDR 1983–85 30,601 17,535 

HIS-20 30,575 42,853 

The numbers in the Lochamy papers do not exactly match the ones from the HIS-20 database 

posted on the O-drive by NIOSH. For example, for the period 1953–1957, the number of 

samples in the HIS-20 database is 3,070, with a maximum of 935 dpm in 1957, while Lochamy’s 

papers cites 3,093 samples for the same period, with a maximum of 10,660 dpm. 

According to the Lochamy paper of April 6, 2006 (Lochamy 2006), HIS-20 produces GM 

(median) and GSD (84th percentile) results larger than CEDR for 1953–1967. In those years, 

CEDR has more records than the HIS-20 data sets. For 1964 and 1965, the CEDR values 

presented in the paper are different from the ones in the RFETS plutonium database used to 

generate intake and doses. In the REFETS table, the GM for 1964 is 0.321 and the GSD is 

0.996, as compared to 0.508 and 3.64, respectively, cited in Lochamy. In the 1965 RFETS table, 

the GM for 1965 is 0.227 and the GSD is 0.70, compared to 0.474 and 2.279, respectively, cited 

in Lochamy. The differences between the CEDR values and the HIS-20 values cited are higher 

for those 2 years. 

6.7.2.1 SC&A Conclusion Regarding the Use of the CEDR Database 

The comparisons of the use of the CEDR database instead of the HIS-20 database focus on the 

comparisons of the values of the GM and geometric mean standard deviation (GMSD). Both 

databases contain a large number of zero results that bring the GM to a very low value, most of 

the time below MDA or reporting levels. Because the lognormal distribution derived for most of 

these years leaves out recorded higher values, as explained in Section 6.7.1.6, the GMSD is also 

not representative of the variation that includes the high excretion values. 

In summary, based on the comparisons between the CEDR and HIS-20 databases, SC&A 

considers the ORAUT-OTIB-0038 modeling approach biased, because the GM is only 

representative of the low excretion rate values. SC&A appreciates that the choice of the best 

parameters to use in this model in order to make it claimant favorable and at the same time “not 

unreasonably claimant favorable” is difficult and most of the time subjective. The model 

parameters have to be reviewed carefully, after considering all possible scenarios of possible 
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contamination of unmonitored workers. The methodology to be adopted to choose those 

parameters may create greater differences in doses than the choice of the CEDR database instead 

of the HIS-20 database. 

SC&A Conclusions Regarding the Internal Coworker Model ORAUT-OTIB-0038 

SC&A examined ORAUT-OTIB-0038 (Arno et al. 2006), the coworker model for internal dose 

assessment, in terms of its conceptual approach, including the overall technical approach used, 

scientific validity, and sufficient degree of conservatism. SC&A accepts NIOSH’s position that 

it is possible to derive a surrogate exposure model for the unmonitored worker based on the 

distribution of internal doses received by the monitored workers at RFP. However, the use of a 

model based on the 50th percentile of the excretion rates of the workers, in the way it was derived 

by NIOSH in the model, will misrepresent the higher exposures experienced by the monitored 

workers at RFP and should not be used for the unmonitored worker. The uncertainties related to 

a model based on the 50th percentile excretion rates of the workers are large and as a 

consequence dose reconstruction cannot be accomplished with sufficient accuracy. 

The ORAUT-OTIB-0038 intake model was derived based on two approaches; a lognormal fit to 

the bioassay data grouped by year or quarter of a year, and an IMBA intake fit to the 50th

percentile excretion rate from the lognormal distributions of several years together. The intake 

rates derived in ORAUT-OTIB-0038 carry uncertainties related to the following: 

• The large discrepancies between the high real results and the ones generated by the 

lognormal curves create uncertainties. The lognormal distribution misrepresents the RFP 

workers who were contaminated routinely in the course of their work. 

• The 50th percentiles, used to derive the intake rates, correspond to very low excretion 

rates and depend on the approach NIOSH uses to account for the zero values and on 

uncertainties related to the MDA values. NIOSH does not discuss or resolve the 

uncertainties related to the MDA values and their relation to the reporting levels and to 

the registered bioassay monitoring values. 

6.7.3 The unmonitored worker’s dose should be based on a model that ensure sufficient 

conservatism and provide for less uncertainty. Adequacy of Internal Monitoring 

 

The petition questions the absence of lung counting capabilities in 1952–1964 and the fact that 

they were “seldom used” from 1964–1968 (USWA 2005). NIOSH concludes in its evaluation 

report that “the lack of routine lung counting prior to the 1960s does not preclude dose 

reconstruction because urinalysis and fecal sampling results are available” (NIOSH 2006a). 

While NIOSH did not provide much detailed substantiation in the evaluation report to support 

this conclusion, SC&A agrees that RFP internal doses can be reconstructed using urinalysis and 

fecal sample results, using claimant-favorable assumptions to complement limited information 

on exposure scenarios. SC&A reviewed the issue of exposures to fire-related plutonium oxides, 

in the absence of lung counting and very low or below MDA excretion results. SC&A 

concluded that dose reconstruction can be accomplished by the simultaneous use of ORAUT-
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OTIB-0049, the intake model from ORAUT-OTIB-0038 based on a percentile equal to or higher 

than the 95th percentile, the missed dose concept using an MDA based on the recovery extreme 

condition, and assumption of continuous exposure between two measurements within a limited 

period of time, no longer than 1 year. This last issue is discussed in more detail in Attachment 3. 
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7.0 DOSE ESTIMATION FOR DECONTAMINATION AND 

DECOMMISSIONING WORKERS 

7.1 BACKGROUND 

NIOSH qualified petition SEC-00030 for the time period 1952–2005, which includes the facility 

closure and D&D phase of operations at RFP, but did not provide a specific evaluation of dose 

estimation for this period of plant operations. During this period at the plant, various former 

production buildings were being torn down, equipment decontaminated and removed, and 

radioactive waste collected and transported off site. First-, second-, and lower-tier 

subcontractors, under the overall management of two successive integrated contractors (EG&G, 

Inc., and Kaiser-Hill), were performing much of this work. These workers often moved between 

specific cleanup jobs on site, as well as on and off site at the RFETS during the cleanup phase of 

operations between 1993 and 2005. Given the residue of some 40 years of radiological 

operations, the potential for radiation exposure was significant for D&D workers. 

Statements by former D&D workers at the Advisory Board meeting of April 25–27, 2006, in 

Denver substantiated the need to characterize the exposure potential of specific jobs and address 

the adequacy of monitoring. One former worker noted that unlike the production era practice of 

conducting routine bioassays (e.g., monthly urinalyses and whole-body counting), monitoring 

practices during the D&D era relied on DAC-hour tracking and air sampling results (lapel 

samplers and area monitoring). These monitoring practices were apparently used to determine 

the need for special bioassays. However, comments made during subsequent Advisory Board 

working group meetings contradicted these statements, when ORAUT personnel with RFP site 

experience indicated that all contractor and subcontractor workers performing work in RCAs 

needed to have Rad Worker II training and would have been afforded routine bioassays. These 

personnel also noted that any lapel sampling or DAC-hour tracking used would be secondary to 

such routine bioassays and would indicate the need for special bioassays and other followup. 

7.2 SC&A REVIEW 

The Advisory Board working group requested that NIOSH review available data for D&D 

workers. Specifically, NIOSH was to compare Rad Worker II training records and site rosters 

for the D&D time period with HIS-20 records to determine if all workers performing radiological 

work (including lower tier subcontractor workers) were included in a routine bioassay program. 

The working group also stressed the need to clarify what was meant by “routine” bioassays, 

given some historic differences in how such bioassays were conducted during the facility closure 

period at various DOE sites (i.e., sometimes annual bioassays were considered routine, whereas 

monthly ones were routine during the production era). 

The working group also asked that NIOSH provide pertinent internal dosimetry policies and 

procedures in place during the D&D period. In addition to these documents, NIOSH also 

identified a series of self-audits of the RFETS dosimetry program conducted in 1996 and 2000. 

The following documents were placed on the O-drive for SC&A review: 
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• Kaiser-Hill Company, Rocky Flats Environmental Technology Site, Radiation Protection, 

Assessment Report, Assessment No. 97-0111-KH, Internal Dosimetry Program (undated; 

field work for assessment conducted between August 11, 1997, and September 4, 1997) 

• Kaiser-Hill Company, Rocky Flats Environmental Technology Site, Radiation Protection, 

Assessment Report, FY04-111-KHAP, March 25, 2004 

• Kaiser-Hill Company, Rocky Flats Environmental Technology Site, Radiation Protection, 

Assessment Report, Assessment of the Rocky Flats Environmental Technology Site’s 

Internal Dosimetry Program, Assessment No. F400-114-KH (undated; field work for 

assessment conducted between April 11, 2000, and April 27, 2000) 

• Rocky Flats Plant, Procedure 1-16200-HSP-18.20, Revision 0, Routine Bioassay 

Monitoring Program, February 8, 1992 

• Rocky Flats Environmental Technology Site, Procedure PRO-1184-RDI-5802, 

Revision 0, Routine Bioassay Monitoring, January 5, 2001 

• Rocky Flats Plant, Procedure 1-H04-HSP-18.20, Rev. 0, Routine Bioassay Monitoring 

Program, March 18, 1994 

SC&A reviewed these documents and provided specific comments to NIOSH. Attachment 27 

provides NIOSH’s responses to those comments (November 1, 2006) and SC&A’s evaluation of 

those responses. 

7.2.1 SC&A Review of RFP and RFETS Documents from the D&D Era 

SC&A’s key comments based on its review of these documents include the following: 

D&D workers not routinely bioassayed and lacking termination bioassays: One implication 

of the Kaiser-Hill self-assessments is that later monitoring found D&D workers who may have 

worked in areas considered to be “cold” to be contaminated with legacy radiological 

contamination. The 2000 audit found a steady decrease in the proportion of terminating workers 

who provided a final bioassay sample. By 1999, only 75% of RFETS employees and 62% of 

lower tier subcontractors received terminal bioassays. Therefore, for those who were exposed to 

potential intakes because their work areas were not surveyed for potential airborne 

concentrations of plutonium, or those who did not meet the narrow definition in the procedures, 

it appears that the termination bioassay program did not have a good backstop. Some of those 

workers were no longer on site and may have been among those who did not submit termination 

bioassays and were not Rad Worker II or respirator-qualified at the time; therefore, were never 

part of the routine bioassay monitoring program. The questions of concern are how many 

workers were in these circumstances and how would dose estimation be addressed. 
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The NIOSH response to this issue follows: 

100% compliance with the termination bioassay requirement was not achieved 

and indeed is not possible at any DOE site. The vast majority (close to 100%) of 

termination bioassay samples were less than the decision level (i.e., not different 

than background) or consistent with known intakes. Workers who didn’t submit 

samples will have maximizing assumptions applied, if appropriate, so this does 

not appear to be an SEC issue. (NIOSH 2006a) 

SC&A next asked to review the dose distributions cited for terminating D&D workers, with the 

following lines of inquiry: 

• Given the relatively higher lack of compliance by lower level subcontractors to 

requirements such as terminal bioassays, would it be appropriate to assume that the dose 

distributions are the same? 

• How can an assumption be made about the appropriateness of an upper-bound 

maximizing assumption for an employee whose internal exposure is unknown (other than 

applying a dose distribution that may or may not be appropriate)? 

If ultimate reliance is placed on the real-time “workplace indicator program and follow-up,” 

SC&A needs to review the records that document the performance of those programs and any 

follow-up bioassays. 

 

Application of RFP bioassay monitoring procedures: RFP routine bioassay procedures from 

the early 1990s provide criteria for inclusion in the routine bioassay monitoring program: 

Individuals routinely performing work in RCAs where the time-weighted monthly 

average (TWMA) of the air sample results is 0.10 of the DAC or greater, or the 

maximum value of an air sample result is greater than 0.30 DAC, are required to 

participate in routine individual monitoring program for that radionuclide. (RFP 

1994) 

While it is clear that the Rad Worker II designation became the basis for routine bioassay 

monitoring, it is not clear how that definition reconciles with these bioassay requirements. 

Likewise, that designation was clearly based on a presumption of an exposure potential to the 

individual that could lead to a dose of 100 mrem/year or more. From NIOSH’s description, this 

designation would have included at least two types of D&D workers from a monitoring 

standpoint: (1) Rad Worker II trained workers who would be bioassayed routinely, would be able 

to work in RCAs, and were assumed to receive potential annual doses at or in excess of 

100 mrem CEDE; and (2) workers who did not have Rad Worker II training but were assumed to 

be exposed to sources of radiation less than 100 mrem/year. SC&A’s interest, in the context of 

this issue, is in how these two worker categories were determined (individual risk assessment, 

DAC-hour tracking, etc.), and to what extent the required routine bioassays (for Rad Worker II 
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workers), termination bioassays (for non-bioassayed workers), and workplace indicator/special 

bioassays (for both) were performed. 

Need to compare Rad Worker II roster with individual bioassay records: SC&A concluded 

that the identified shortcomings and issues raised about the bioassay of D&D workers make it 

imperative to compare the Rad Worker II roster after 1993 (which represented the best 

approximation of which D&D workers were working in radiological areas) with individual 

bioassay records in order to validate that the workers did, in fact, receive routine bioassays. 

NIOSH questioned the “shortcomings” identified and informed the working group and SC&A of 

the following: 

While the request to compare the rad worker II-trained employees to bioassay 

records seems straightforward, in fact it would be quite complex. There is no rad 

worker II training roster per se. The program worked like this. When it had been 

one year since each employee’s last Pu urine bioassay, the bioassay database 

queried the training records database to determine the training and respirator-fit 

status. If the training and respirator-fit status were current, it then queried the 

HIS-20 database to see if an entry had been made in the previous 12 months. 

Since site closure, these databases exist in some form, but are not able to 

communicate as they did when the site was operational. Basically, to do what is 

being requested, one would have to start with a list of employees and look them 

up in three systems. For each employee a matrix of the dates of entry into the 

program, rad worker II training dates, respirator fit dates, HIS-20 entry dates, 

termination date(s), and bioassay sample dates would have to be set up. Where 

bioassays appeared to be missing, a memo field would have to be examined. This 

field might contain such information as, “employee on short-term disability; no 

sample until return.” The hardcopy file might also have to be recalled to 

determine the exact cause of a failure to submit a sample. Currently, no one on 

the ORAU/NIOSH side has access to all of the necessary records systems, and we 

would have to rely on resources from DOE Legacy Management. The return on 

this investment of time and energy would be a determination that some high 

percentage of people received bioassay samples on schedule. 

(NIOSH 2006a) 

This response did not change SC&A’s conclusion that the documents provided on the issue 

(bioassay policies, procedures, and self-assessments) did not answer questions about the 

adequacy and completeness of radiation records associated with D&D activities at RFP. In fact, 

these documents actually raised additional issues as cited above (i.e., lack of terminal bioassays, 

lack of integration of lower tier subcontractors into the bioassay program, and proper basis for 

Rad Worker II training) that NIOSH’s response does not sufficiently address. The working 

group was to address in more detail NIOSH’s conclusion that it is too “complex” to validate the 

routine bioassays conducted for Rad Worker II workers performing D&D. SC&A considered the 

conclusion that, a priori, validating these bioassays would not be justified in any case, because 

NIOSH can already predict that “some high percentage of people received bioassay samples on 
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schedule” (NIOSH 2006a) to be speculative and nonevaluative for purposes of a review in the 

SEC context. SC&A noted in subsequent working group discussions that, if these data 

inadequacies are substantiated, at the very least, some consideration should be given to coworker 

modeling for D&D workers. NIOSH indicated that it was open to that suggestion, although it 

considered it a TBD issue, not an SEC concern (ABRWH 2006d). 

Other issues raised by SC&A (e.g., how Rad Worker II designations were made and the intent 

and meaning of certain RFETS audit findings) were clarified by NIOSH in its response and 

accepted by SC&A, as noted in Attachment 27. 

7.2.2 OCAS-TIB-0014 

In light of the NIOSH finding that a comparison between the Rad Worker II roster and individual 

bioassay data would be too complex and resource intensive, the working group, following 

discussion at its November 6, 2006, meeting, requested that NIOSH “provide termination 

bioassay data (fecal, urine, or in vivo) available for RFETS workers during the D&D period 

(1993 forward)” (ABRWH 2006d). The working group asked that “this data include information 

indicating whether each individual worked for the prime contractor or a subcontractor.” 

Secondarily, the group asked NIOSH to “provide for review an assessment of the sufficiency of 

data to support decontamination and decommissioning (D&D) coworker model development.” 

In response, NIOSH issued on December 7, 2006, a new OCAS-TIB-0014, Rocky Flats Internal 

Dosimetry Coworker Extension (Allen 2006b), which extends the existing ORAUT-OTIB-0038 

(Internal Dosimetry Coworker Data for Rocky Flats Environmental Technology Site) (Arno et al. 

2006) beyond the latter’s 1953–1988 date to Rocky Flats cessation of operations in 2005, thereby 

encompassing the D&D era. The extension is based on urinalysis data in HIS-20 and provides 

projected intakes by year. 

SC&A finds that OCAS-TIB-0014, which assumes a lognormal distribution fit to uranium and 

plutonium bioassay results from chronic intakes during the period 1989–2005, is conceptually 

adequate. However, OCAS-TIB-0014 states that this TIB did not address Am-241 lung data, 

with the number of such samples dropping significantly in 1990. On the other hand, the 

December 18, 2006 NIOSH discussion paper Analysis of Termination Bioassay Results for 

Rocky Flats during Shutdown and D&D Era (1990 to mid 1995) (NIOSH, 2006b) (also in 

Attachment 27) states that lung counting was the preferred method of termination bioassay in the 

later years of the site. SC&A sought to reconcile these two statements in the context of whether 

and how OCAS-TIB-0014 addresses in vivo counting results. 

7.2.3 Termination Bioassay Data Comparison 

As an alternative means to demonstrate the comparability of dose distributions between the 

broader contractor and D&D subcontractor population, NIOSH provided a comparison of 

termination bioassay results for plutonium and uranium. Results were provided for (1) top-tier 

contractors, (2) all subcontractors, and (3) D&D subcontractors. In the cover e-mail 

accompanying its December 18, 2006, review in Attachment 27, NIOSH concluded that the 
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results “do not show any significant differences between top-tier contractors and all subs, or 

between top-tier contractors and D&D subs,” and that NIOSH remained “confident that the 

internal coworker data developed for the D&D era can appropriately be applied to all workers 

regardless of employer, as necessary” (NIOSH 2006b). 

SC&A reviewed the December 18 analysis of termination bioassay results and generally concurs 

with the NIOSH assessment, although SC&A did need to clarify several outstanding issues (see 

below). For RFETS, it is apparent to SC&A from discussions with site experts that the extensive 

use of operating workers (e.g., steelworkers) by the top-tier contractors for much of the initial 

“hot” radiological work (e.g., initial decontamination and contaminated equipment removal) in 

place of less experienced subcontractors had a leveling effect on dose distribution between the 

two groups. This leveling effect is borne out in the NIOSH dose distribution comparisons 

between the three worker groups. Regardless of the explanation, the similarity of the dose 

distribution for terminal bioassays between the two worker populations is persuasive on the issue 

of applicability of coworker models. 

 

However, NIOSH based its review on a comparison of urine samples. The 1992 Routine 

Bioassay Monitoring Program (1-16200-HPS-18.20) required an annual feces routine sampling 

for exposure to plutonium, and the Derived Investigation Level for plutonium was based on fecal 

sampling (RFP 1992). Fecal sampling was required at the end of jobs that had a high potential of 

an intake greater than the investigation level. The exit request for workers who were in a routine 

bioassay program for plutonium in their last 12 months on site consisted of three fecal samples. 

The 1994 Routine Bioassay Monitoring Program (1-H04-HPS-18.20) defined the exit bioassay 

requirements for plutonium or americium as urine or lung count for Category I workers and feces 

or lung count for Category II workers. Category II workers were defined as workers with an 

elevated risk of internal exposure, while Category I workers would not have a high risk of 

internal exposure (RFP 1994). The following analysis evaluates this issue in greater detail. 

7.2.4 Analysis of Fecal versus Lung Count Issue 

On January 24, 2007, NIOSH issued a document entitled Response to SC&A Comments on 

“Analysis of Termination Bioassay Results for Rocky Flats during the Shutdown and D&D Era 

(1990–2005), December 18, 2006” and OCAS-TIB-0014 (NIOSH 2006c). In this document, 

NIOSH stated the following: 

for a time in the early 1990s, Rocky Flat’s interpretation of the DOE bioassay 

requirement was that the minimum detectable dose for the routine program was to 

be 100 mrem. This concept also applied to termination sampling. The only 

sampling means available for plutonium which could approach 100-mrem 

sensitivity was fecal sampling. DOE subsequently clarified its position and 

routine and exit urine sampling was resumed. The 2/2/1995-version of HSP 18.20 

(pp. 36-65, SRDB Ref. ID 24241) eliminated the Category I and II definitions and 

specified urine or lung count as the exit bioassay. 
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There were a number of logistical problems associated with large fecal sampling 

programs that Rocky Flats quickly discovered. The first attempt at off-site 

contracting for fecal bioassay resulted in all fecal sample results being 

invalidated due to quality problems. It is believed that most of these workers 

were subsequently asked to submit a urine sample. It is unclear how many 

termination fecal samples may have actually been submitted in lieu of termination 

urine samples, but the number probably was not large. Letters were placed in the 

individual files indicating the samples were invalid. 

Another important point is that the original question involved subcontractors in 

the D&D era. The analysis included data from 1990–2005. In 1989 production 

operations were suspended. From 1990 to 1994, Rocky Flats’ contractors 

undertook a massive effort to restart the Plant. However, this effort was mostly 

to improve the documentation (procedures, etc.) that would allow the restart of 

production. Maintenance, radiation surveys, and the like were still performed 

in contaminated areas, but not production, and not major D&D. The decision 

not to restart and to begin the D&D of the facility was made in 1994. However, 

the D&D era did not start in earnest until after the new contractor, Kaiser-Hill 

Company, was brought on in mid-1995. Therefore the use of termination fecal 

bioassay would not have biased the results during the actual D&D era.

[Emphasis added] 

NIOSH also noted the following: 

The coworker extension (OCAS-TIB-0014) used urine results in the HIS-20 

database. Most of these were routine results, but some were termination samples 

or incident-related samples. The years affected by the fecal sampling program 

were 1990–1994 at most. If there was a significant negative bias introduced, it 

would be apparent when examining the OCAS-TIB-0014 results. A graphical 

representation is shown below, in which part of the data in Table A-2 is plotted. 
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Urine Excretion Rates from OCAS-TIB-0014

0

0.02

0.04

0.06

0.08

0.1

0.12

1/1/1989 1/1/1990 1/1/1991 1/1/1992 1/1/1993 1/1/1994 1/1/1995 1/1/1996 1/1/1997 1/1/1998 1/1/1999

Effective sample date

Dpm/24 hours

50th 84th

Routine Fecal Sampling

At first glance this plot may appear to show that the urine results were actually 

biased high during the time period when there could have been fecal samples 

collected as the routine bioassay. In reality, this plot shows the improvement in 

the analytical laboratory procedures over the years. Leading up to the 

implementation of 10 CFR 835 in 1996, Rocky Flats made a concerted effort to 

improve the MDA for plutonium in the on-site bioassay laboratory, as well as to 

contract with the best off-site bioassay laboratories available. The driver was the 

need to demonstrate that the routine bioassay program could detect 5 rem CEDE. 

To accomplish this with an annual urine sampling program required world-class 

laboratories and alpha spectroscopy counting facilities. Most laboratories 

offering these services could not meet Rocky Flats’ MDA and/or QA/QC 

requirements. The above plot demonstrates that any possible low bias introduced 

by fecal sampling was insignificant compared to the effect of the plutonium 

MDAs. (NIOSH 2006c) 

SC&A accepts these NIOSH contentions with respect to the remaining question regarding 

potential bias introduced by use of fecal termination bioassays, especially considering the 

NIOSH statement that the D&D era did not start in earnest until mid-1995 (which SC&A has 

corroborated in discussions with former site workers). 

7.2.5 Analysis of OCAS-TIB-0014 

As noted previously, SC&A accepts the concept of applying OCAS-TIB-0014 as an extension of 

ORAUT-OTIB-0038 for worker populations in the D&D era. However, SC&A finds that the use 

of a model based on the 50th percentile of the excretion rates of the workers will misrepresent the 
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higher exposures experienced by unmonitored subcontractors at RFP. SC&A is supportive of 

intake models based on a percentile equal to or higher than the 95th. As in its review of ORAUTOTIB-0038, which OCAS-TIB-0014 extends to the D&D era, SC&A notes that the intake model 

for OCAS-TIB-0014 was derived using an IMBA fit for a period of several consecutive years. 

As a consequence, for some time periods, the dose will be calculated using an intake rate that 

corresponds to urinary excretion values smaller than the chosen percentile (50th or 95th). Thus, 

when NIOSH uses the 50th percentile or the 95th percentile intake rates, it should not be 

understood as the 50th or 95th percentile of the workers’ intake rates. These rates correspond to a 

model intake rate that will fit the chosen percentiles, with some periods of time when the urine 

excretion rates will be underestimated, and some periods of time when they will be 

overestimated. SC&A considers these uncertainties in the adequacy of the bioassay program and 

in the completeness of radiation records associated with D&D activities at RFP to be large, and 

that a coworker model based on the 50th percentile of the bioassay records does not adequately 

address these uncertainties. 

SC&A also finds OCAS-TIB-0014 to be incomplete because it does not address in vivo counting 

results. For respiratory organ dose calculations, ORAUT-OTIB-0014 recommends applying 

Type M plutonium, followed by the minimizing Type S intake. If both actions do not yield a 

probability of causation (POC) > 50%, NIOSH recommends manually fitting the coworker 

bioassay data for the timeframe of interest for the employee, using the assumption of Type S 

material. In ORAUT-OTIB-0038, this manual fit of the data includes americium lung data. The 

uncertainties associated with the calculation of doses to the lung from urine data are large. The 

correlation of plutonium retention in the lungs with the excretion rate in urine is indirect and 

depends on the chemical and physical forms. Different matrix materials containing plutonium 

may have specific dissolution behavior. Absorption parameters depend on the production 

temperature. The method of formation of the material and its history (temperature, specific 

surface area) can influence the fraction rapidly absorbed and the long-term retention half-time. 

The different types of material encountered in D&D activities produce different urinary excretion 

patterns. As a consequence, there is an increased uncertainty in the association of the urinary 

excretion rate with lung retention or lung deposition. 

 

7.2.6 Conclusion Regarding Dose Estimation for D&D Workers 

SC&A concurs with NIOSH’s conclusion about its ability to conduct dose estimation with 

sufficient accuracy for the D&D era of plant operations based on its favorable comparison of 

termination bioassay data between “top-tier” operating contractors and identified D&D 

subcontractors. Subsequent NIOSH-provided analyses that address potential bias introduced by 

use of fecal termination bioassays have satisfied issues related to SC&A’s evaluation of OCASTIB-0014, NIOSH’s draft bulletin that extends ORAUT-OTIB-0038 (internal dose coworker 

model) beyond 1988. However, similarly to ORAUT-OTIB-0038, OCAS-TIB-0014 uses the 

50th percentile rather than the 95th percentile to derive intakes, which may not be claimant 

favorable. 
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8.0 DATA COMPLETENESS EVALUATION 

The Advisory Board’s criteria for evaluation of SEC petitions include several that relate to the 

data underlying dose reconstruction (ABRWH 2006a). These criteria fall under the general 

rubric of the “credibility and validity of the dataset.” The intent of these criteria relates to 

NIOSH’s ability to perform dose reconstructions: 

For each petition evaluation, NIOSH will typically review the available exposure 

data for that site and then focus on a few key sets of exposure data (including 

exposure sources) to determine if those data at that site are adequate for 

completing individual dose reconstructions for all members of the class.

(ABRWH 2006a)

The Board elaborated on the meaning of the term “credibility and validity of the dataset” by 

specifying the following criteria: 

(1) Pedigree of the Data: This includes determining “the relation of the exposure monitoring 

to documented activities at the site during that time period” and ensuring that “secondary 

sources of data...are consistent with the original data set....” 

(2) Methodology: This includes an evaluation of “the documented methodology for the data 

set including whether reliable corrective estimation procedures have been applied and are 

appropriate.” 

(3) Relation to Other Sources of Information: This includes a demonstration that “the data 

are appropriate for...estimating the maximum plausible dose for any member of the 

class.” 

(4) Internal Consistency. 

(5) Representativeness: This includes considerations of whether the various periods, areas, 

types of work and processes, source terms, and adequacy of data are “representative of 

the highest exposed individuals within the class.” 

The procedures approved by the Board for its contractor in evaluating SEC petitions and in 

reviewing NIOSH’s evaluation reports on SEC petitions also involve an investigation of the 

completeness of the internal and external dose data sets that NIOSH proposes to use for dose 

reconstruction for any member of the class (SC&A 2006d). 

Initial inquiries focused on the completeness of the HIS-20 electronic database and its 

relationship to the underlying data. Comparison of the database with information in logbooks 

and claimant files revealed that the HIS-20 database is incomplete and that workers whose 

employment ended before 1977 may not be represented in the database. Another database, the 

CER database, was also found to be incomplete. In response, NIOSH stated that it would rely on 

individual dose records in DOE files as the principal source of data for individual dose 
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reconstruction and on the HIS-20 and/or CER electronic database for coworker models. As a 

result, the completeness of the data in the DOE files became an issue, since those data are the 

primary source for the NIOSH individual dose reconstructions. This section examines the issue 

of the completeness of individual dose data as reflected in the Rocky Flats claimant files. 

This investigation was necessary because there is no complete compilation of dosimetry data that 

reflects essentially all the data in the DOE files. Gaps in data—that is, periods when there were 

no measurements whatsoever—indicate a need for methods to fill those gaps. These gaps are 

essentially different from zeros in the data records, which reflect measurements below the 

detectable limit that can be filled in various ways, including by using the LOD or LOD/2 or some 

value in between. Coworker models may be needed if gaps are significant, or if whole groups of 

workers were not monitored at certain facilities or in certain periods or both. 

SC&A conducted a broad investigation of the completeness of Rocky Flats external and internal 

monitoring data in claimants’ DOE files, using minimal criteria for completeness, to ascertain 

whether substantial gaps exist that need to be filled. This broad investigation is distinct from a 

more detailed evaluation that would, for instance, involve a review of each badging cycle for 

external dose. 

SC&A conducted two types of completeness evaluations. In the first, SC&A examined external 

and internal dose data in DOE responses in the records of 32 randomly selected claimants. The 

second consisted of examinations of the DOE responses in the records of 20 claimants who were 

judged by Rocky Flats in the 1990s to have high cumulative radiation doses. The randomly 

selected cases show the general extent of the gaps in Rocky Flats worker records. An 

examination of the records of claimants with high cumulative exposures provides a preliminary 

view of whether there is a basis for filling the gaps in dosimetry data for the rest of the worker 

population, if such gaps exist. In each case, the investigation of gaps focused on the data in DOE 

files for a particular claimant. SC&A also did a preliminary evaluation of the job records of the 

20 claimants with high cumulative exposures to ascertain whether a pattern existed for certain 

gaps in the external dose records. (This evaluation does not cover external dose gaps in 1969, 

which are discussed in Section 4.3.1 of this report.) 

The 32 random claims were selected in three waves. An initial set of four (Wave 1) was chosen 

from among Rocky Flats dose reconstructions already audited by SC&A. These were among the 

cases randomly selected by NIOSH and presented to the Advisory Board, which selected the 

cases from across the weapons complex to be audited by SC&A. The next eight (Wave 2) were 

obtained by picking the first Rocky Flats case for a claimant who was employed for 5 years or 

more from 1-999 claimant numbers on the NIOSH R-drive, then one case from the 1,000 to 

1,999 group, one from the 2,000 to 2,999 group, etc., until there were a total of eight cases. A 

preliminary analysis was conducted to determine whether the gaps found were sufficient to 

warrant a further inquiry. Finally, the last 20 (Wave 3) were selected using a randomized search 

procedure, with the added limitations listed below: 

• Two periods, 1951–1963 and 1964–1992, were represented among those selected, so that 

they could be studied separately. These time periods were selected because Rocky Flats 
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integrated its security and film badge in 1964. This made the earlier period a statistically 

different distribution—and indeed, data on the fraction of workers monitored in the first 

period indicate a fairly steady increase during the years from startup through the early 

1960s. The data show a sudden jump in the fraction of employees badged in 1964. 

Table 8.1 (reproduced in full in Attachment 7), which is taken from a NIOSH paper on 

Rocky Flats badging practices, shows the percentage of workers badged by year. 

• Each claimant file selected represented a claimant who worked at the Rocky Flats Plant 

for at least 5 years. 

• The sampling was done without regard to whether dose reconstruction had been 

completed. Only files pulled by NIOSH from the dose reconstruction process (17 out of 

1,165) were excluded from the sampling. 

Attachment 28 describes the sampling procedure for selecting the 20 cases. 

The total of 32 cases was selected to provide a reliable picture of the gaps in Rocky Flats 

workers’ DOE records. Table 8.1 shows that larger gaps should be expected in the 1951–1963 

period for external dose than in the 1964–1992 period. Note that the frequency of monitoring 

declined again beginning in 1992. This was the year that production ended and the transition to 

decommissioning of Rocky Flats began. Decommissioning formally started in 1993. 

Table 8-1. Percent Badged 

Year Badged Year Badged Year Badged Year Badged Year Badged Year Badged 

1951 1961 77% 1971 94% 1981 96% 1991 91% 2001 73% 

1952 5% 1962 78% 1972 94% 1982 96% 1992 82% 2002 72% 

1953 33% 1963 75% 1973 94% 1983 97% 1993 80% 2003 56% 

1954 34% 1964 93% 1974 98% 1984 96% 1994 65% 2004 40% 

1955 43% 1965 93% 1975 97% 1985 98% 1995 65% 2005 25% 

1956 53% 1966 96% 1976 96% 1986 97% 1996 67% 

1957 61% 1967 95% 1977 97% 1987 98% 1997 79% 

1958 63% 1968 91% 1978 98% 1988 98% 1998 83% 

1959 63% 1969 74% 1979 98% 1989 98% 1999 83% 

1960 71% 1970 90% 1980 97% 1990 96% 2000 80% 

Source: ORAU analysis of RFP claimant files 

Source: Langsted 2006 

Figure 8.1 shows the data in Table 8.1 in graph form. 

The data in Table 8.1 and Figure 8.1 should be treated with some caution since they are based on 

a sample whose representativeness has not been established. Specifically, the percentages are 

derived from a review of 1,046 Rocky Flats claimant files (Langsted 2006). While this is a large 

sample, the representativeness of claimants to the entire Rocky Flats workforce, including 

subcontractors, covered by the proposed SEC class has not been established and no method to do 

so is evident. Specifically, the job types and periods represented by the claimant file sample may 

not correspond to the proportions in the worker population. Some job types may not be 

represented. The practical consequences of this issue are discussed later in this chapter. 
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Notably, the year 1969 shows a sharp drop in proportion badged. This appears to be the result of 

equating the gaps in the external dosimetry record as nonmonitoring. Strictly speaking, many 

badges that were issued were not read, even though they were issued. (See analysis of the 1969 

data in Section 4.3.1.) SC&A concurs that unread badges should be treated as if the employee 

were not monitored in that period. 

External Gamma Monitoring

0

20

40

60

80

100

1950 1960 1970 1980 1990 2000 2010

Year

% monitored

Figure 8-1. Proportion of Workers Monitored for External Dose at Rocky Flats 

Source: Langsted 2006 

The DOE dose records of the 32 claimants were divided into two periods, 1951–1963 and 1964–

1992. This is because a combined ID and film badge was issued in 1964, which resulted in over 

90% of the workers being badged until the transition to D&D in 1992. In addition, separate 

tables were created for external dose (deep gamma) and internal dose. If in any year, there were 

no external dose records at all (even zeros), but only blanks, that year was counted as a gap in 

external dose data. (The term “gap” is used both to mean a blank in the records or no 

measurement indicated in the record. It does not include zeros in the record, which are counted 

as measurements at less than the LOD.) Note that counting a year as one that has data does not 

affirm that there are complete data for that year—that is, it does not mean that a record exists for 

each badge cycle. Similarly, for internal dose data, a year counted as a gap in the data is one in 

which there was no bioassay (urine or fecal) record and no in vivo count. If there was a data 

point for any one of these categories in a given year, the year was not counted as a year without 

data. Gaps for partial years at the start of employment and at the end of employment were not 

counted. The initial and final year data were rounded to zero, half year, or full year, as follows: 

• 0 to 2 months = zero 

• 3 to 8 months = half year 

• 9 months or more = full year 

SC&A also compiled cumulative data on the data gaps. In these cumulative compilations, 

partial, initial, and final years were counted according to the rounding scheme described. 
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In addition to the analysis of the 32 cases randomly selected, a sample of 20 cases from among 

those judged in the 1990s to have the highest cumulative doses (internal committed dose 

equivalent plus external deep dose) were examined to assess completeness of records for those 

workers. ORAU performed the exposure assessment in the 1990s as a retrospective. This part of 

the completeness evaluation has particular relevance for development of coworker models.8

8.1 EXTERNAL DOSE—RANDOM SAMPLE 

Table 8.2 shows the analysis for the external dose records for the 32 claimants in the random 

sample. 

Table 8-2. Rocky Flats External Dose Data Completeness Analysis—Random Samples 

Period Number of 

workers 

Number with 

gaps of 1 year 

or more 1,4

Percentage of 

workers with 

gaps of 1 year 

or more 1

Cumulative 

years 

employed 

Cumulative 

gap–years4

Percentage 

cumulative gap 

1951–1963 14 4 29% 76.5 16.0 21% 

1964–1992 30 10 2 33% 368 37.0 3 10% 1

 This column does not count first or last partial year gaps. 

2

 Of the 10 employees with gaps of 1 year or more in 1964–1992, 4 had gaps only in 1992. 

3

 1969 gaps in data may be for part of the year or the full year. This compilation does not count 1969 data gaps 

as full-year gaps. The 1969 issue is briefly addressed below and more fully in Section 4.3.1 of this report. 4

 A gap is recorded for the year if there are no film badges or TLD data at all for that year. Zero entries are 

counted as positive indications of recorded data. Only blank records are included in the compilation of the 

gaps. 

The percentage cumulative gap in the external dose data was greater in the 1951–1963 period 

than in the 1964–1992 period. This result confirms the data compilation by NIOSH presented in 

Table 8.1, which shows that a significant proportion of workers was not badged in the early 

period. The proportion of badged workers went from 5% in 1952 to a high of 78% in 1962. 

Overall, about 21% of the cumulative years worked by the 14 employees had no external dose 

records (partial years counted as 0 or 0.5 years, as noted above). 

The proportion of workers with at least a 1-year gap was about the same in the two periods 

(about 30%). However, the high value for the latter period is largely due to the transition year of 

1992. Of the 10 workers with a gap of at least 1 year, 4 had a gap only in 1992. An 

investigation into job types may yield insight into the reasons. If the analysis excludes these 

four, 20% of the workers had a gap of at least 1 year in their external dose records. As noted, 

this analysis does not include partial-year gaps; as long as one record exists in a given year, that 

year is excluded from the compilation of data gaps. It is, therefore, a minimal criterion of 

 8

 This draft report does not include the detailed compilations of the claimant data. These compilations may 

contain Privacy Act information. The spreadsheets have been sent to the CDC for evaluation of content related to 

the Privacy Act. 
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completeness for external dose data. The section on highly exposed workers discusses issues 

related to dose reconstruction. 

SC&A found several records with gaps for all or part of 1969. This finding reflects the 

cumulative data compilation of monitoring frequency provided by NIOSH and discussed above. 

However, a specific problem appears to affect 1969 external dose data. In that year, Rocky Flats 

management decided not to read the film badges of workers on a 3-month badge cycle. The 

March 1969 monthly status reported this change: 

Quarterly badges for the non-Pu areas will no longer be read routinely, except 

for a few higher dose risk groups. The film will be changed as usual, but will not 

be read unless circumstances warrant. (Piltingsrud 1969a) 

It is not clear whether and when this policy was rescinded. Not reading film badges that were 

issued and then handed in appears to SC&A to be a questionable practice, which even apparently 

surprised NIOSH/ORAU consultant and Rocky Flats dose expert, Roger Falk (see 

Attachment 29). 

The problem of blank external dosimetry records before 1969 and after the start of the 

integration of the ID badge and the film badge in 1964 continued after 1970. For instance, one 

of the workers in the random sample of 32 had external dosimetry gaps (blanks) from 1963–1973 

(inclusive). NIOSH has stated that this worker was not issued a badge (November 6, 2006, 

working group meeting transcript, pp. 76–79). It is not clear how the nonreading of issued 

badges is to be differentiated from nonissuance of badges to prime contractor personnel. 

During the working group meeting of March 7, 2007, NIOSH stated that not all workers who 

were prime contractor employees after 1964 were badged. SC&A has not found any clear 

documentation regarding a policy for determining who was excluded. The NIOSH paper on 

badging practices (Langsted 2006) does not clarify this problem. For the 1964 combined badges, 

the paper quotes the 1982 Rocky Flats history as follows: 

In 1964, we were able to incorporate the dosimetry badge with the security 

badge. This was an improvement from the standpoint of assuring the employee 

was indeed wearing a badge while working on the job. (Rocky Flats History as 

quoted in Langsted 2006) 

 

This does not indicate that all prime contractor workers were badged. However, the Langsted 

paper also quotes a 1974 memo that states, “we have issued all employees on plant site (Dow and 

AEC) a TLD dosimeter” (as quoted in Langsted 2006). This implies that some Dow and AEC 

personnel may not have been given TLDs from the time of their introduction in 1970, or perhaps 

film badges from the time of the introduction of the combined film badge and ID in 1964. The 

NIOSH investigation into badging practices throws some light into who was brought into the 

badging program in 1974, but it provides no explicit criteria for who was excluded in 1964. The 

evidence is clearer concerning which subcontractor workers continued to be excluded after 1970 

(see below). 
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8.2 RANDOM SAMPLE—INTERNAL DOSE 

Table 8.3 shows the summary data for the random samples for internal dose data from 32 

claimants. 

Table 8.3. Rocky Flats Internal Dose Data Completeness Analysis—Random Samples 1 

Period Number of 

workers 

Number with 

gap of 1 yr or 

more 2

Percentage 

workers with 

gaps of 1 yr or 

more 2

Cumulative 

yrs employed 

Cumulative 

gap in yrs 

Percentage 

cumulative 

gap 

1951-1963 14 4 29% 76.5 9.0 12% 

1964-1992 30 22 73% 368.0 122.5 33% 1

 A gap for a full year is recorded if there are no bioassay data (urine or fecal) and if there are no in vivo data. A 

single measurement in any of these categories is counted as a year with data. This approach cannot be directly 

related to dose reconstruction feasibility but provides a modest test of data availability for internal dose. 2

 This column does not count data on first or last partial year gaps. 

Surprisingly, nearly three-fourths of the workers in the random sample had at least 1 year of no 

internal dose measurements in the 1964–1992 period, though the total cumulative working years 

with no internal dose records was about one-third. Smaller internal dose measurement gaps 

occurred in the early period. The next section discusses the issues raised by these gaps as they 

concern internal dose reconstruction for workers with high cumulative exposure. 

8.3 SAMPLE OF WORKERS WITH HIGH CUMULATIVE EXPOSURE 

As noted, SC&A also analyzed the DOE files of 20 Rocky Flats claimants who were assessed as 

having high cumulative exposure in a retrospective analysis done in the 1990s. That analysis 

categorized workers into groups numbered 1 through 4, with 1 representing the lowest 

cumulative exposures (external plus internal) and 4 representing the highest exposures. SC&A 

chose 10 claimants from group 4 and 10 from group 3 for analysis. The selection process began 

with an SC&A request to NIOSH to provide the full lists of claimants in group 3 and group 4. 

NIOSH provided a list of 22 group 4 claimants. SC&A selected the first five and last five from 

this list. For group 3, NIOSH sent a list of 35 claimant numbers. SC&A selected 

approximately every third number from this list until it had a total of 10.

The analysis found no full-year gaps in internal dose data for this group of 20 workers. This 

applies to both the early (1951–1963) and late (1964–1992) periods. The early period includes 

63 cumulative years of employment in the 1950s. The database is apparently sound enough to 

permit an analysis of the feasibility of one or more coworker models for all members of the class 

through 1992. SC&A has not performed such an analysis but recommends that the analysis 

include a review of the data related to workers with high cumulative exposure. This would allow 

NIOSH to examine the job types represented to determine if they include all those with a 

potential for high internal exposure relative to the various source terms present at Rocky Flats, or 

if the exposures for the job types that are represented bound those that are not represented for 

various periods where production operations or other factors, such as materials brought in or 
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processed, changed. Additionally, it is important to verify that the available data are sufficient to 

reconstruct doses due to incidents, especially when exposure was to materials of high or medium 

solubility. Specifically, in view of the large proportion of workers (nearly three-fourths) in the 

random sample who had a gap of at least 1 year in their internal dose records, it is essential that 

the job types of group 3 and group 4 workers be analyzed relative to the workers who have gaps 

in their data, before a coworker model can be deemed to be suitably claimant favorable. 

The picture regarding external dose is somewhat different. There are essentially no full-year 

gaps in external dose data records for this group of 20 claimants from 1960 onward. However, 

numerous gaps exist for the 1951–1959 period, notably for claimants in group 3. Specifically, 

about 62% of the cumulative employment years for group 3 workers lacked any external dose 

data in this period; the total for group 4 was 19%. Most of the gaps relate to the initial years of 

employment. 

The gaps in the 1950s most likely reflect the partial external dose monitoring for Rocky Flats 

workers, as discussed above. In an interview, SC&A sought an explanation for these gaps from 

Roger Falk, a site expert, who responded as follows: 

They may have started work in a non-radiation area or in a lower job 

classification. Rocky Flats was a coveted place to work. What I have observed 

and known to have happened was that anyone would apply for a low-level job, 

such as Janitor, and work their way up into better positions as he proved himself. 

I don’t know if it happened in the cases that you looked at. (Attachment 29) 

SC&A did a preliminary analysis of the job cards of both group 3 and group 4 workers in order 

to determine whether any pattern emerged in a screening analysis. It appears that most of the 

full-year data gaps in the 1950s are associated with work in Production Plant B, which consists 

mainly of Building 81 (or 881), where enriched uranium was processed. Some gaps occurred for 

workers in the QC laboratory and the “pipe shop.” There were no full-year gaps for external 

dose data (as defined above) in Production Plant C, where plutonium was processed. SC&A 

confirmed Dr. Falk’s observation that many workers started as janitors or laborers and worked 

their way up but could not confirm the implication in his statement that the gaps relate mainly to 

nonradiological work. The progression in job type was rather rapid, and the data gaps do not

relate mainly to the period of employment in nonradiological jobs. On the contrary, they occur 

mainly in the years when the employees in question were in radiological areas and mainly in 

Production Plant B. A review of the job cards, therefore, provides a reasonable explanation for 

the gaps in the data. 
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8.4 NIOSH DOSE RECONSTRUCTIONS FOR SAMPLED CASES 

A core argument made by NIOSH to assert its ability to reconstruct doses in a manner that meets 

the purposes of 42 CFR Part 83 is that it has completed dose reconstructions in almost all the 

cases examined in the data completeness evaluation discussed above. In its February 2007 

paper, NIOSH stated the following about these 52 cases and the data gaps in many of the 

records: 

There was not a single case where an employment period without monitoring data 

adversely impacted NIOSH’s ability to conduct dose reconstruction with sufficient 

accuracy, as evidenced by completed dose reconstructions for 48 of the 52 

individual claimants examined, 60% of which had probabilities of causation 

greater than 50%. NIOSH therefore concludes that the monitoring data in the 52 

claimants’ radiation files is sufficient for dose reconstruction, and therefore does 

not present an SEC issue. (NIOSH 2007c)

SC&A finds that the claim that no SEC issue is involved because dose reconstructions have been 

completed under 42 CFR Part 82 does not fulfill the requirements of 42 CFR Part 83. 

Specifically, 42 CFR Part 82 allows research to be cut short for purposes of efficiency in either 

minimum or maximum dose calculations. In the former case, only a partial dose determination is 

made, since the POC at the minimum dose determined is over 50% and the claim is likely to be 

compensated. By definition, a minimum dose estimate is not a bounding estimate or an estimate 

with the accuracy required under 42 CFR Part 83. Similarly, efficiency methods of maximum 

dose use inputs that can grossly overstate dose and have no clear connection with the employee’s 

work. These dose estimates are used only for denial of claims. In contrast, the dose 

reconstruction with sufficient accuracy stipulated under 42 CFR Part 83 must use methods that 

result in estimates that can be used both to compensate and to deny claims. SC&A concludes 

that, as a general matter, dose reconstructions completed under 42 CFR Part 82 do not 

necessarily demonstrate the feasibility of dose reconstruction with sufficient accuracy under 42 

CFR Part 83. 

In the specific case of Rocky Flats, 50 of the 52 cases examined by SC&A in the data 

completeness evaluation have completed dose reconstructions. Of the 50 completed cases, 31 

were compensated, but almost all of them (28 of 31) were minimum dose reconstructions. In 12 

of the 28 compensated cases, no external dose was calculated at all; in one case, only medical 

dose was sufficient to compensate. Of the 19 denials, 15 used an efficiency technique for 

internal dose for cutting short research (see ORAUT-OTIB-0002 (ORAUT 2007a)). Further, the 

dose reconstructions do not cover all the job types that are in question here. For instance, the 

sample of 52 claimants included no foundry workers from the 1950s. 

SC&A looked more closely at the workers who had gaps in their external dose records and at the 

method NIOSH used to complete the external dose reconstruction in such cases. Of the 50 

completed dose reconstructions, the cases of 24 workers had gaps of 1 year or more in their 

external dose records. Of these, NIOSH did not reconstruct the external dose for 13. In 4 of the 

11 cases where NIOSH imputed a value to the external dose, it used the LOD as the basis for 
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doing so. For instance, in one case, a group 3 worker (high cumulative dose) worked in Plant B 

and had no dosimeter during his employment in the 1950s. The 1950s gap in the energy 

employee’s external dose record was not mentioned in the dose reconstruction report. However, 

entries in the Interactive RadioEpidemiological Program input tables for 1955–1959 appear to 

have been obtained by assuming some sort of missed dose distribution corresponding to LOD 

values; it is not obvious how these values were derived. If these values were derived in this 

manner, it creates the problem of assuming a dose at or below the LOD when there was in fact 

no monitoring. In effect, this puts nonmonitoring on a par with a zero-dose reading. This is not 

scientifically appropriate. 

In two of the remaining seven cases, NIOSH used a value of 0.1 rem to fill a 1992 monitoring 

gap, since that was the value for determining whether a person was badged after 1992. This 

value appears to be in line with prior monitoring results and the change in policy defining who 

was to be badged. The year 1992 was a transition year from production to D&D. SC&A broadly 

concurs with NIOSH regarding dose reconstruction during D&D as it pertains to 42 CFR Part 83. 

The issue at hand is the ability of NIOSH to make estimates with sufficient accuracy during the 

production period. These two cases are not relevant to that period. 

In one of the remaining five cases, NIOSH used the ambient dose and in another it used 

150 mrem per quarter, or half of 10% of the 3-rem quarterly dose limit. None of these cases are 

relevant to bounding dose estimates for the class. 

NIOSH estimated a dose relating to actual badge data and working conditions in only 3 of 24 

cases that had a gap of 1 year or more. These cases are relevant to demonstrating the ability of 

NIOSH to make a bounding dose estimate. 

 

In one case, the worker’s highest dose from the period of recorded dose was assigned to the 

periods where there were gaps, in addition to missed dose. The dose reconstruction report raises 

the possibility that the badges may have been lost. SC&A is not debating the merits of the 

claimant favorability of the approach adopted in this case. In the context of the SEC evaluation, 

the material issue is whether an ad hoc assignment of dose without knowledge of working 

conditions contributes to demonstrating NIOSH’s ability to estimate a bounding dose for filling 

gaps for members of the SEC class. SC&A believes that knowing the working conditions and 

relating those working conditions to the dose estimate are crucial to dose reconstruction with 

sufficient accuracy under 42 CFR Part 83. 

In the second case where NIOSH used a dose assignment other than LOD, there was a data gap 

of 9 years in the 1970s and 1980s. Monitoring records existed for most other years. This gap 

was filled each year with the value in the year of highest recorded dose (0.32 rem). This case 

involved a subcontractor employee who was actually not employed at Rocky Flats between early 

1975 and 1983 (inclusive).9

 Hence, an assignment of dose is claimant favorable but 

scientifically dubious, at best. In any case, it is not an SEC issue, since the gap in data is 

9

 This is noted in NIOSH 2007c. SC&A verified the termination and restart dates from the DOE records in 

the claimant’s file. 
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explained by the sporadic nature of the subcontractor employee’s work. This kind of dose 

assignment when the employee was actually not employed is arbitrary (any value may be 

assigned from zero on up) and is irrelevant to making a bounding dose estimate. 

Some internal dose gaps occurred during periods of employment. Out of 23 years, 17 had no 

internal monitoring data. Since the worker was issued a badged during some of these years, 

there may well have been potential for internal exposure. No internal dose reconstruction using 

Rocky Flats data was done in this case; instead, ORAUT-OTIB-0002 was used. This TIB is used 

to estimate worst-case internal doses only for denial. Hence, for both internal and external dose, 

these cases illustrate why a completed dose reconstruction cannot be accepted as evidence of 

NIOSH’s ability to estimate a bounding dose for all members of a proposed SEC class. 

However, SC&A has found that the internal dose gaps themselves are not an SEC issue, since 

there are no annual gaps for workers with high cumulative doses. 

NIOSH used its coworker model in only one case to fill a gap in the dose record. It did so for an 

employee who had a blank in his 1969 record (full year) and other gaps of less than 1 full year. 

This employee worked in a variety of areas, including Building 44, which includes the foundry, 

and plutonium areas. The framework used in the dose reconstruction was that for plutonium 

workers, which was stated to be claimant favorable. Shallow doses were assigned on the basis of 

<30 keV photons. The gap for 1969 for <30 keV photons was filled with a coworker model dose 

of 0.216 rem. Interestingly, all shallow doses in prior years, based on measured and missed dose 

data, are much higher, ranging from a low of just under 0.5 rem to a high of over 5 rem. The 

latter dose is higher than the 95th percentile value in the coworker model. The value for 

coworker dose used in the dose reconstruction for 1969 is lower than all recorded values up to 

1968 and two of the recorded values between 1970 and the early 1980s. No part of the dose 

construction explicitly considered job assignments in the area of potentially high shallow dose, 

Building 44, even though the person worked in that area, among others. His job assignment card 

shows that he was assigned to Buildings 44 and 81 in 1969. His dose record does show a sharp 

drop in shallow dose after the gap in 1969. 

In view of the preceding, SC&A concludes that in the only instance among the 50 dose 

reconstructions in which NIOSH used the external dose coworker model to fill an external dose 

data gap for a full year, the result did not demonstrate its ability to bound the doses in the areas 

where this evaluation has discovered gaps. 

Finally, NIOSH has completed dose reconstructions at sites for which SECs have subsequently 

been granted. 

In summary, SC&A does not agree with NIOSH’s claim that the completed dose reconstructions 

for the cited cases at Rocky Flats provide evidence of its ability to complete dose reconstructions 

with sufficient accuracy under 42 CFR Part 83 for all members of the proposed SEC class, or 

even for those members of the class likely to have the kinds of external dose data gaps discussed 

above. 
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8.5 DATA GAPS AND COWORKER MODELS 

Since gaps in external dose data are substantial for nonplutonium workers in the 1950s even 

among workers with high cumulative exposures, it is essential to examine whether the available 

external dose data are sufficient to fill those gaps. Since all identified gaps for the workers with 

high cumulative exposures were in nonplutonium areas, SC&A explores the implications of that 

finding, beginning with the DU area (Plant A, mainly Building 444, also called Building 44), 

which may have had the greatest exposure potential among the nonplutonium areas. Following 

this exploration is a discussion of Plant B (mainly Building 81, also called Building 881), where 

most of the gaps were found. 

Because of the beta-emitting decay products of U-238 (Th-234 and Pa-234m), U-238 has a much 

higher potential for shallow dose than Pu-239/Pu-240. Furthermore, uranium foundry operations 

resulted in separation of these two decay products, which flowed to the surface of the uranium. 

In those operations, beta dose rates were as high as 2,000 to 3,000 mrad/h on castings of DU in 

the early years, which is an order of magnitude higher than equilibrium contact beta dose from 

uranium metal (Putzier 1982). Contamination of workplace surfaces with dust high in Th-234 

and Pa-234m could result in very high and nonuniform skin doses. Since shallow dose 

measurements from later years may not reflect early radiological conditions, it may be difficult 

to use later data to retrospectively estimate shallow dose, or even deep dose for uranium workers. 

Concentrated, nonequilibrium areas of contamination with Th-234 and Pa-234m not shielded by 

massive uranium metal could also lead to higher deep exposure rates from the various gamma 

photons associated with these radionuclides (including photon energies of 131 keV, 1.9 MeV, 

63 keV, and 92 keV). One way of approaching the problem would be to examine whether there 

are sufficient data from the nonplutonium areas in the periods of high exposure potential (such as 

the early period) to allow the creation of a coworker model that would meet the test of 42 CFR 

Part 83 for dose reconstruction sufficient accuracy. 

NIOSH has pointed out that the foundry, where the U-238 disequilibrium with its daughter 

products would be important, was in Building 44. At the working group meeting of March 7, 

2007, NIOSH distributed some samples of film badge dosimetry logbook data sheets for 1953 

for Building 44. The data sheets contain worker names and external film badge readings, but no 

job designations. NIOSH stated that the personnel badged included management. SC&A also 

investigated the availability of similar data for other years in the 1950s for Building 44, which 

NIOSH made available and which are also posted on NIOSH’s Site Query Database. SC&A 

verified that data are available for Building 44 for the 1950s, but was unable to ascertain whether 

foundry workers or other workers at high risk of exposure were systematically included. SC&A 

has no reason to believe that such groups of workers would have been systematically excluded 

from the monitoring. However, the dosimetry data sheets do not contain job information, and 

job types carrying a risk of higher exposure cannot be identified from that data set. Badge 

exchanges for Building 44 were weekly or biweekly in this period. 

A mix of employees, including management, appears to have been badged in Building 44; this, 

together with the short badge exchange cycle, means that many or most badges were below the 

LOD. However, some employees clearly had a shallow dose well above the 10% limit 
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considered to be the trigger point for monitoring, and some had external doses above this limit as 

well. For instance, one employee in Building 44 had a deep dose of at least 1.4 rem during the 

third quarter of calendar year 1955.10

NIOSH should compile the highest readings for deep and shallow doses for the 1950s in 

Building 44 and compare them to its coworker model to validate or, if necessary, modify the 

model. This is unlikely to be an SEC issue if the job types of the highest exposed employees in 

Building 44 can be determined. This determination should not be limited to claimant files; 

rather, it should be made from the files of the employees with the highest external doses in the 

1950s in Building 44, regardless of their claimant status. These steps are necessary to fulfill the 

requirements of 42 CFR Part 83, since foundry workers in the 1950s may have been at higher 

risk of external exposure, notably shallow dose, than plutonium workers during the 1950s. 

In its paper evaluating a draft of SC&A’s data completeness review, NIOSH stated that there 

were no external film badge data for Building 81 (part of Plant B) for the 1950s (NIOSH 2007c). 

It also stated that “[t]he unmonitored periods in the 1950s were primarily for enriched uranium 

workers in Building 81” (NIOSH 2007c, p. 5). 

NIOSH provided examples of the conservatism of its coworker model for Building 81 workers 

for 1960 (by extrapolating the data available for one quarter to the whole year) and for 1961. 

SC&A concurs that the coworker model bounds the dose in the examples provided for the years 

evaluated. However, extrapolating backwards into the 1950s on the assumption that similar 

processes and lower production levels would result in lower doses is not warranted without 

specific supporting data. Dust levels can vary widely in the DOE weapons complex and Atomic 

Weapons Employers even when equipment and production levels are similar. Further, dust 

levels experienced by individual workers are not necessarily related to production levels, unless 

production decreases so much that individual workers are no longer doing the job full time. This 

can affect external shallow dose. Further, external dose rates may also vary depending on the 

details of how the work was done and the specific enrichments of uranium being handled. Data 

such as area external dose rates and industrial hygiene dust data from the 1950s are needed to 

validate NIOSH’s assertion regarding Plant B exposures in the 1950s. 

In reviewing the documents for available data, SC&A did find a few instances of data for 

Building 81 for the 1950s, but the badges in question appear to have been issued for special 

circumstances. For instance, a Co-60 source was present in Building 81 between December 10 

and 13, 1956. Some badges were reassigned from Building 83 to health physics personnel in 

Building 81 for monitoring this exposure.11 Data for a few people in Building 81 in the month of 

December are also available in other years in the 1950s. No badges appear to have been 

routinely issued to any group of Building 81 workers up to 1960. 

10 Film Badge Results, 1955, p. 352 of the pdf file of scanned dosimetry data sheets. The cumulative dose 

for the quarter up to September 2, 1955, was 1.4 rem. 11 Film Badge Results, 1956, scanned Rocky Flats external dose dosimetry data sheets, pp. 369–373 of the 

pdf file. 
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It may be possible to establish external dose exposure rates from enriched uranium by an explicit 

review of working conditions in the 1950s and their comparability to the early 1960s if data such 

as area monitoring badges and area dust loadings are available for both periods. 

These remarks about coworker models are statements of theoretical feasibility. The coworker 

models themselves need to be developed and tested in actual dose reconstructions. 

SC&A checked whether the workers who had gaps were in the HIS-20 database during the 

periods of the gaps. Of the 52 employees evaluated for data completeness, 26 had gaps of 1 

entire year or more in external monitoring. Generally, the gaps identified in the worker dose 

records were also represented as gaps in HIS-20, except for 1969 (as discussed in Section 4.3.1). 

This is a positive finding for the HIS-20 database, since unmonitored workers can be identified 

by the gaps in the electronic database, except for 1969 and probably 1970. 

Findings Regarding External Dose Coworker Model for the 1950s

• Significant gaps in external dose data were identified for the 1950s. The gaps are 

associated with work in nonplutonium areas and are mainly in Plant B. 

• Many data sheets for external dose exist for workers in Building 44 (Plant A), but these 

data are not accompanied by job descriptions or titles. Since foundry workers cannot be 

identified directly from these data sheets, a determination is necessary that the existing 

coworker model would cover the highest exposed workers. Alternatively, documentation 

on badging practices in the 1950s for Building 44 would establish what job types were 

covered. NIOSH needs to demonstrate that its coworker model would bound Building 44 

doses for foundry workers or that monitoring for this group was routine enough to 

obviate the need for a coworker model. 

• Production workers in Building 81 were generally not badged in the 1950s. NIOSH’s 

statements that production peaked in a period after monitoring began, and that major 

processes were the same in the 1960s as in the 1950s, cannot, on their own, be used to 

establish the assumption that doses were the same or lower in the 1950s. NIOSH needs 

data, such as air monitoring and area badging data, to support its conclusion that 1960s 

data can be used for bounding dose for the 1950s. 

Overall conclusion regarding external dose gaps: NIOSH has not yet done the necessary 

work to develop the bounding dose estimates or to show that its coworker model is claimant 

favorable for the kinds of gaps that exist for external dose, notably in the 1950s. However, 

NIOSH could address the gaps in external dose in various ways, such as the use of data from the 

site and existing or modified coworker models. 

Overall conclusion regarding internal dose coworker model: Since the internal dose data for 

highly exposed workers do not show annual gaps, it is likely that the gaps in internal dose can be 

filled by one or more suitable coworker models designed to appropriately reflect job types and 

periods of employment. However, this still needs to be accomplished and demonstrated. 
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8.6 OTHER ISSUES REGARDING COMPLETENESS OF DOSE DATA 

8.6.1 Subcontractor Workers 

During the working group’s deliberations, NIOSH stated that subcontractors were not necessarily 

badged, even in the period when the ID badge and film badge were integrated into one device. 

The data provided by NIOSH and cited above also indicate that the proportion of monitored 

workers did not reach 100% at any time, but stayed a few percent below that throughout the 

period of production. According to NIOSH, subcontractor workers, like all other RFP workers 

in the 1964–1991 period, were required to be monitored when they entered radiological areas 

(ABRWH 2006d, pp. 74–78). There is also evidence that the badging policies for subcontractor 

workers covered more personnel in the late 1960s and early 1970s (Langsted 2006). 

Of the 52 cases examined, one was for a subcontractor worker. This case had external dose 

monitoring data for the periods of employment and showed a 9-year gap for a period when the 

person was not employed at Rocky Flats. For external dose, this example provides some 

corroboration of NIOSH’s statement regarding badging of subcontractor workers. However, 

there were full-year gaps in the internal dose record during periods of employment and external 

dose monitoring. 

SC&A has found no evidence that subcontractor workers were not monitored when they were in 

radiological areas. Specifically, SC&A has not found any systemic violation of the policy that 

would have resulted in unbadged subcontractor workers going into areas with radiological 

exposure potential. SC&A also notes that between 1964 and 1991, the proportion of unbadged 

workers was small in almost all years (less than 10% and generally in the 2%–6% range—see 

Table 8.1 above). The one instance of a subcontractor worker evaluated by SC&A and described 

above tends to corroborate NIOSH’s statement of badging practices. 

The issue of attributing a suitably bounding dose for subcontractor workers who were not badged 

or not monitored for internal dose when they were in radiological areas needs to be addressed, 

especially for the 1950s and possibly also the 1960s. For 1970 and later, an explicit numerical 

criterion for badging subcontractor personnel was cited in the NIOSH 2006 paper (however, 

subcontractor personnel with low exposure potential may not have been issued a dosimeter): 

6.15.1 Conditions where General Health Physics Surveillance is Not 

Required 

a. In areas where penetrating radiation levels are not likely to exceed an 

average of 0.2 mrem/hr., outside contractor personnel may be utilized. 

Film badges will not be provided under these conditions unless, on advice 

of Health Physics, badging is desired for assessing a possible criticality 

exposure.” (Putzier 1970) 

The maximum potential unrecorded dose for a working year of 2,000 hours would be 400 mrem. 

Hence, it appears possible to bound the dose for subcontractor workers after 1970, if the policy 
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was enforced. Some verification would be desirable and may be possible by examining claimant 

files for subcontractor personnel. 

The problem is more difficult for the period prior to 1970 and especially for the 1950s. In the 

latter case, a large proportion of workers was not badged. The difficulties in regard to 

subcontractor personnel, such as construction workers, need to be explicitly analyzed. NIOSH 

has produced TIB ORAUT-OTIB-0052 (ORAUT 2006) on construction workers that includes 

those at Rocky Flats, and SC&A is in the process of reviewing it. The detailed data on which the 

NIOSH Rocky Flats assessment of construction workers is based are not yet available. 

8.6.2 Unbadged Prime Contractor Workers 

At the March 7, 2007, working group meeting, NIOSH stated that a small percentage of prime 

contractor workers was not badged, even after the introduction of the combined ID and 

dosimeter badge. The one example identified during the random sampling of Rocky Flats claims 

was that of a secretary who did not have monitoring for 10 years after the combined ID and film 

badge was issued. NIOSH has stated that no badge was issued for this worker, but this is not 

evident in the worker’s file. It is also possible that the practice of not reading badges was 

instituted earlier than 1969, but there is no documentary evidence for this. The policy of 

nonreading of badges that was spelled out explicitly in 1969 applied to workers on a quarterly 

badge cycle who were thought to be at a low risk of exposure. The secretary’s case, where the 

gap was much longer than the other sample cases, fits this profile. 

If the practice of nonbadging parallels the earlier pre-1964 periods of nonbadging or nonreading 

of issued badges, it is likely that the practice applied to workers who were thought not to have 

high exposure potential (see also the discussion of the 1969 external dose records in Section 

4.3.1). However, this is an inference; it is not a sufficient basis for demonstrating that a 

bounding dose approach exists for unbadged workers. 

8.7 OVERALL CONCLUSIONS REGARDING COMPLETENESS 

SC&A has performed an extensive analysis of the issue of the completeness of dosimetry data in 

DOE files, which are stated by NIOSH to be the primary basis for dose reconstruction for 

individual claimants. This analysis included a random sample of 32 claimant files and a selected 

sample of 20 files of claimants who were assessed by Rocky Flats in the 1990s to have high 

cumulative exposure (external plus CDE internal). The overall conclusions for the period 1951–

1992 (except 1969) are as follows: 

• SC&A does not agree with NIOSH’s claim that the completion of dose reconstruction 

under 42 CFR Part 82 for almost all of the 52 cases evaluated for data completeness 

establishes that it can estimate doses with sufficient accuracy for all members of the class 

under 42 CFR Part 83. 
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• Substantial gaps exist in external dose data for the 1950s. The investigation of the high 

cumulative exposure cases indicates that these gaps are likely related to work in Plant B 

and some other areas not associated with plutonium processing facilities. 

• Extensive badge data exist for Building 44, where the foundry was located. NIOSH 

should show either that foundry workers, or other workers who may have been at risk of 

high shallow dose, were routinely badged or that sufficient data are available for this job 

type to fill any gaps that may exist in dose data. 

• For Plant B (mainly Building 81) workers, NIOSH has not established that backwards 

extrapolation from the early 1960s into the 1950s, when there are almost no dosimetry 

data, provides a bounding dose approach. A suitable approach using appropriate data, 

such as area monitoring badge data and dust data, remains to be developed. 

• There are large gaps in internal dose data, notably for the 1964–1992 period, during 

which almost three-fourths of the workers had gaps of at least 1 year in internal dose 

measurements. About one-third of the cumulative years of employment had no 

measurements in the 1964–1992 period. These observations relate to the random sample. 

• The bioassay data for the highly exposed workers have essentially no gaps for full years. 

Since the internal dose data for highly exposed workers do not show annual gaps in any 

period to 1992, it is likely that the gaps in internal dose can be filled by one or more 

suitable coworker models designed to appropriately reflect job types and periods of 

employment (see Section 6.7 on internal dose coworker model). 

• SC&A has evaluated NIOSH’s claim that the dose reconstructions of almost all of the 

claimants from among the 52 evaluated suffice to demonstrate its ability to do dose 

reconstruction with sufficient accuracy under 42 CFR Part 83. SC&A has concluded that 

the completion of these dose reconstructions does not demonstrate that ability as it relates 

to 42 CFR Part 83 for members of the proposed class. 

Rocky Flats has extensive dosimetry data, but there are also gaps in the data for some periods 

and some types of workers. NIOSH has not demonstrated its ability to fill existing data gaps for 

external dose in a manner that would produce bounding dose estimates that would satisfy the 

requirements of 42 CFR Part 83. SC&A found that in the one instance among the 50 dose 

reconstructions where NIOSH used the external dose coworker model to fill an external dose 

data gap for a full year, the results did not demonstrate NIOSH’s ability to bound the doses in the 

areas where gaps have been revealed in this evaluation. However, the availability of data means 

that there may be approaches to make bounding dose estimates. NIOSH should either develop 

these approaches or demonstrate that the existing coworker model is bounding for the specific 

categories of workers who have gaps in their external dose records. 
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9.0 REFERENCES 

42 CFR 83, 2000. Code of Federal Regulations, Title 42, Part 83: Procedure for Designating 

Classes of Employees as Members of a Special Exposure Cohort under the Energy Employees 

Occupational Illness Compensation Program Act of 2000. 

ABRWH (Advisory Board on Radiation and Worker Health) 2006a. Report of the Working 

Group on Special Exposure Cohort Evaluation, draft dated January 16, 2006, approved by the 

Board at its January 24–26, 2006, meeting in Oak Ridge, Tennessee. 

ABRWH (Advisory Board on Radiation and Worker Health) 2006b, Transcripts from Working 

Group Meeting, Advisory Board on Radiation and Worker Health, Rocky Flats, Advisory Board 

on Radiation and Worker Health, Teleconference on April 12, 2006.

ABRWH (Advisory Board on Radiation and Worker Health) 2006c, Transcripts from Working 

Group Meeting, Advisory Board on Radiation and Worker Health, Rocky Flats, Advisory Board 

on Radiation and Worker Health, Hebron, Kentucky, July 26, 2006, pp. 329–337. 

ABRWH (Advisory Board on Radiation and Worker Health) 2006d. Transcript of the Rocky 

Flats Working Group Meeting on November 6, 2006. On the Web at 

http://www.cdc.gov/niosh/ocas/pdfs/abrwh/wgtr110606.pdf. 

ABRWH (Advisory Board on Radiation and Worker Health) 2006e, Transcripts from Working 

Group Meeting, Advisory Board on Radiation and Worker Health, Rocky Flats, Advisory Board 

on Radiation and Worker Health, Hebron, Kentucky, August 31, 2006. 

ABRWH (Advisory Board on Radiation and Worker Health) 2006f, Transcripts from Working 

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Effective Date: 

April 5, 2007 

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

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Effective Date: 

April 5, 2007 

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JCUSC 1971a, Joint Company-Union Safety Committee Concern Form, Rocky Flats Plant, Dow 

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JCUSC 1971b, Joint Company-Union Safety Committee Concern Form, Rocky Flats Plant, Dow 

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JCUSC 1974, Joint Company-Union Safety Committee Concern Form, Rocky Flats Plant, Dow 

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JCUSC 1975, Joint Company-Union Safety Committee Concern Form, Rockwell International, 

Golden, Colorado, 1975. 

JCUSC 1984, Joint Company-Union Safety Committee Concern Form, Rockwell International, 

Golden, Colorado, 1984. 

JCUSC 1985a, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 6/84), 

Rockwell International, Golden, Colorado, 1985. 

JCUSC 1985b, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 6/84), 

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JCUSC 1985c, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 6/84), 

Rockwell International, Golden, Colorado, 1985. 

JCUSC 1986a, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 6/84), 

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JCUSC 1986b, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 6/84), 

Rockwell International, Golden, Colorado, 1986. 

JCUSC 1986c, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 6/84), 

Rockwell International, Golden, Colorado, 1986. 

JCUSC 1986d, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 6/84), 

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JCUSC 1987a, Joint Company-Union Safety Committee Concern Form, Rockwell International, 

Golden, Colorado, 1987. 

JCUSC 1987b, Joint Company-Union Safety Committee Concern Form, Rockwell International, 

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JCUSC 1987c, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 11/86), 

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Effective Date: 

April 5, 2007 

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

JCUSC 1989a, Joint Company-Union Safety Committee Concern Form, Rockwell International, 

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JCUSC 1989b, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 4/89), 

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JCUSC 1989c, Joint Company-Union Safety Committee Concern Form, Rockwell International, 

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JCUSC 1989d, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 4/89), 

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JCUSC 1989e, Joint Company-Union Safety Committee Concern Form, Rockwell International, 

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JCUSC 1989f, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 4/89), 

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JCUSC 1990a, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 2/90), 

Rockwell International, Golden, Colorado, 1990. 

JCUSC 1990b, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 4/89), 

Rockwell International, Golden Colorado, 1990. 

JCUSC 1991a, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 2/90), 

EG&G Rocky Flats, Golden, Colorado, 1991. 

JCUSC 1991b, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 10/90), 

EG&G Rocky Flats, Golden, Colorado, 1992. 

JCUSC 1991c, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 2/90), 

EG&G Rocky Flats, Golden, Colorado, 1991. 

JCUSC 1991d, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 10/90), 

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JCUSC 1992a, Joint Company-Union Safety Committee Concern Form, Rockwell International, 

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JCUSC 1992b, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 10/90), 

EG&G Rocky Flats, Golden, Colorado, 1992. 

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Effective Date: 

April 5, 2007 

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0 – Draft 

Document No. 

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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. 

JCUSC 1993a, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 7/90), 

EG&G Rocky Flats, Golden, Colorado, 1993. 

JCUSC 1993b, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 10/90), 

EG&G Rocky Flats, Golden, Colorado, 1993. 

JCUSC 1993c, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 10/90), 

EG&G Rocky Flats, Golden, Colorado, 1993. 

JCUSC 1994a, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 10/90), 

EG&G Rocky Flats, Golden, Colorado, 1994. 

JCUSC 1994b, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 10/90), 

EG&G Rocky Flats, Golden, Colorado, 1994. 

JCUSC 1994c, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 10/90), 

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JCUSC 1994d, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 10/90), 

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JCUSC 1994e, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 10/90), 

EG&G Rocky Flats, Golden, Colorado, 1994. 

JCUSC 1995a, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 10/90), 

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JCUSC 1995b, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 10/90), 

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JCUSC 1996, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 10/90), 

EG&G Rocky Flats, Golden, Colorado, 1996. 

JCUSC 1997, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 10/90), 

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JCUSC 1998, Joint Company-Union Safety Committee Concern Form, RF-45500, (Rev. 7/97), 

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JCUSC 1999a, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 12/97), 

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JCUSC 1999b, Joint Company-Union Safety Committee Concern Form, RF-45500 (Rev. 7/97), 

Kaiser Hill Company, Golden, Colorado, 1999. 
Effective Date: 

April 5, 2007 

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0 – Draft 

Document No. 

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

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April 5, 2007 

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Integrity Memo, Office of Compensation and Analysis, Cincinnati, Ohio, April 14, 2006. 

NIOSH (National Institute of Occupational Safety and Health) 2006e, NIOSH Evaluation of 

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NIOSH (National Institute of Occupational Safety and Health) 2006g, Logbook Review for 

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NIOSH (National Institute of Occupational Safety and Health) 2006j, Data Integrity Samples 

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Effective Date: 

April 5, 2007 

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Investigations Regarding 1969 Data Gap, Office of Compensation and Analysis, Cincinnati, 

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NIOSH (National Institute of Occupational Safety and Health) 2007b, NIOSH Evaluation of 

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NIOSH (National Institute of Occupational Safety and Health) 2007f, NIOSH’s Response to 

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Effective Date: 

April 5, 2007 

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April 5, 2007 

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Abbreviated External Dose Reconstruction, 4-J88-RDE-0053, Rocky Flats Environmental 

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RFETS (Rocky Flats Environmental Technology Site) 1997b, Extended External Dose 

Reconstruction, 4-J98-RDE-0071, Rocky Flats Environmental Technology Site, Golden, 

Colorado, August 1, 1997. 

RFETS (Rocky Flats Environmental Technology Site) 2001, Rocky Flats Environmental 

Technology Site External Dosimetry Technical Basis Document, Rev. 2, Golden, Colorado, 

September 25, 2001. 

RFP (Rocky Flats Plant) 1965, Logbook 3/26/65-10/18/65, Rocky Flats Plant, Dow Chemical 

Company, Golden, Colorado. 

RFP (Rocky Flats Plant) 1966a, Logbook 12/5/66-6/11/67, Rocky Flats Plant, Dow Chemical 

Company, Golden, Colorado. 

RFP (Rocky Flats Plant) 1966b, 1966–1969 Special Analysis Logbook, Rocky Flats Plant, Dow 

Chemical Company, Golden, Colorado. 

RFP (Rocky Flats Plant) 1966c, RFP Logbook 5/10/66–12/3/66, Rocky Flats Plant, Dow 

Chemical Company, Golden, Colorado. 

RFP (Rocky Flats Plant) 1967, RFP Logbook 6/12/67–12/29/67, Rocky Flats Plant, Dow 

Chemical Company, Golden, Colorado. 

RFP (Rocky Flats Plant) 1986, 1985/1986 Dosimetry Problem Logbook, Rocky Flats Plant, 

Rockwell International, Golden, Colorado. 

RFP (Rocky Flats Plant) 1990a, External Dose Equivalent Investigation 1990 A-L, EG&G Rocky 

Flats, Golden, Colorado, 1990. 

RFP (Rocky Flats Plant) 1990b, External Dose Equivalent Investigation 1990 M-Z, EG&G 

Rocky Flats, Golden, Colorado, 1990. 

RFP (Rocky Flats Plant) 1991, External Dose Equivalent Investigation 1991, EG&G Rocky 

Flats, Golden, Colorado, 1991. 
Effective Date: 

April 5, 2007 

Revision No. 

0 – Draft 

Document No. 

SCA-SEC-TASK5-0052, Volume 1 

Page No. 

230 of 231 

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. 

RFP (Rocky Flats Plant) 1992. Rocky Flats Plant, Procedure 1-16200-HSP-18.20, Rev. 0, 

Routine Bioassay Monitoring Program, February 8, 1992. 

RFP (Rocky Flats Plant) 1994. Rocky Flats Plant, Procedure 1-H04-HSP-18.20, Rev. 0, Routine 

Bioassay Monitoring Program, March 18, 1994. 

RFP (Rocky Flats Plant) 2007, AEC/ERDA/DOE Rocky Flats Thorium Inventory Information 

(Partial), assembled by Rocky Flats Classification & Classified Records Management Office, 

February 8, 2007 (declassified records). 

RI (Rockwell International) 1976, Memorandum to File, TLD Information on [Name] [Man 

No.], Health Physics File, Rockwell International, Golden, Colorado, August 30, 1976. 

RI (Rockwell International) 1983, External Thermoluminescent Dosimetry (TLD), Rocky Flats 

Plant, Rockwell International, Golden, Colorado, April 29, 1983. 

RI (Rockwell International) 1987, 1986 Annual Report—Radiation Exposure to Rockwell 

Employees at the Rocky Flats Plant, Radiation Safety, Health, Safety and Environment 

Department, Rockwell International, Golden, Colorado, June 1987. 

RMRS (Rocky Mountain Remediation Services, LLC) 1999, Thermoluminescent Dosimeter 

Storage Locations Background Subtraction Methodology, Technical Basis Document, December 

17, 1999. 

Savitz, K.R., 1996, Memorandum from K.R. Savitz to File, Double Background Subtraction, 

KRS-008-96, Kaiser Hill Company, Golden, Colorado, July 24, 1996. 

SC&A (S. Cohen and Associates) 2005a, Supplemental Review of the Mallinckrodt Site Profile 

Revision 1, Supplement to SCA-TR-TASK1-0002, Vienna, Virginia, April 18, 2005. 

SC&A (S. Cohen and Associates) 2005b, First Supplemental Review of the Bethlehem Steel Site 

Profile, ORAUT-TKBS-0001, Draft Rev. 2, Vienna, Virginia, September 2005. 

SC&A (S. Cohen and Associates) 2005c. Draft Issue Resolution Matrix for Findings and Key 

Observations Contained in the Rocky Flats Plant Site Profile Review, Rev. 00, McLean, Virginia. 

December 15, 2005. 

SC&A (S. Cohen and Associates) 2005d. Draft Rocky Flats Plant Site Profile Review, SCA-TRTASK1-0008, McLean, Virginia. December 8, 2005. 

SC&A (S. Cohen and Associates) 2006a, Memorandum from K. Robertson-DeMers to A. 

Makhijani and J. Fitzgerald, Rocky Flats Interviewees and Records Review, Vienna, Virginia, 

April 5, 2006. 
Effective Date: 

April 5, 2007 

Revision No. 

0 – Draft 

Document No. 

SCA-SEC-TASK5-0052, Volume 1 

Page No. 

231 of 231 

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 (S. Cohen and Associates) 2006b, RFP Data Integrity Process May 19, 2006, Vienna, 

Virginia, May 19, 2006. 

SC&A (S. Cohen and Associates) 2006c, Interim Evaluation of Data Reliability Issues: Needed 

Document Retrieval and Evaluation, Vienna, Virginia, April 19, 2006.

SC&A (S. Cohen & Associates) 2006d. Board Procedures for Review of Special Exposure 

Cohort Petitions and Petition Evaluation Reports. June 12, 2006. 

SC&A (S. Cohen and Associates) 2006e. Attachment 2: Site Expert Interview Summary for the 

SC&A Draft Review of the NIOSH Site Profile for the Rocky Flats Plant, McLean, Virginia, 

May 9, 2006. 

Smith, M., 2005a, Supplementary External Dose Information for Rocky Flats Plant, ORAUTOTIB-0027, Oak Ridge Associated Universities, Oak Ridge, Tennessee. May 19, 2005. 

Smith, M., 2005b, Use of Rocky Flats Neutron Dose Reconstruction Project Data in Dose 

Reconstructions, ORAUT-OTIB-0050, Oak Ridge Associated Universities, Oak Ridge, 

Tennessee. December 13, 2005. 

Smith, M., 2006, External Coworker Dosimetry Data for the Rocky Flats Plant, ORAUT-OTIB0058, Rev. 00, Oak Ridge Associated Universities, Oak Ridge, Tennessee, April 6, 2006. 

Smith, M., 2007, External Coworker Dosimetry Data for the Rocky Flats Plant, ORAUT-OTIB0058, Rev. 01, Oak Ridge Associated Universities, Oak Ridge, Tennessee. January 8, 2007. 

Ulsh, B. 2007, E-mail communication from B. Ulsh (NIOSH) to A. Makhijani (SC&A), March 

16, 2007. 

Ulsh, B., 2006, E-mail from B. Ulsh to K. Robertson-DeMers, RE: Question Regarding RFP 

1969 Fire List, National Institute for Occupational Safety and Health, Office of Compensation 

and Analysis, Cincinnati, Ohio, December 19, 2006. 

USWA (United Steel Workers of America) 2005, Rocky Flats Plant Special Exposure Cohort 

Petition, Golden, Colorado, February 15, 2005. 

USWA 1997, Joint Company Union Safety Committee Concern Form, Case 97-163, RF-45500 

(Revised October 1990), Kaiser Hill Company, Golden, Colorado, June 12, 1997. 

Vogel, R.M., 1969, Memorandum from R.M. Vogel to J.R. Mann, Non-plutonium Area Film 

Badge Recommendation, Rocky Flats Plant, Dow Chemical Company, Golden, Colorado, March 

3, 1969.