REPORT TO THE ADVISORY BOARD 

ON RADIATION AND WORKER HEALTH

National Institute of Occupational Safety and Health 

Audit of Case PIID* from the Rocky Flats Plant 

Contract No. 200-2004-03805 

Task Order No. 4 

SCA-TR-TASK4-CNPIID* 

Prepared by 

S. Cohen & Associates 

6858 Old Dominion Road, Suite 301 

McLean, Virginia 22101 

February 2005 

NOTICE: This information is protected by Privacy Act 5 USC §552a; disclosure to any third party without 

the written consent of the individual to whom the information pertains is strictly prohibited. 
Document No. 

SCA-TR-TASK4-CNPIID* 

Effective Date: 

February 4, 2005 

S. Cohen & Associates:

Technical Support for the Advisory Board on 

Radiation & Worker Health Review of 

NIOSH Dose Reconstruction Program Revision No. 1 

AUDIT OF CASE PIID* FROM THE ROCKY 

FLATS PLANT

Page 2 of 11 

Task Manager: ___________________ Date: 02/04/05 

 U. Hans Behling, PhD, MPH 

Project Manager: _________________ Date: 02/04/05 

 John Mauro, PhD, CHP 

Supersedes: 

Draft Rev. 0 

Rocky Flats Plant Case PIID* 2 S. Cohen & Associates 
TABLE OF CONTENTS 

1.0 Summary Background Information .................................................................................... 4 

1.1 Audit Objectives ..................................................................................................... 4 

1.2 Summary of Audit Findings.................................................................................... 5 

2.0 Audit of Assigned Doses .................................................................................................... 8 

2.1 Internal Exposure to the Lung From Missed Dose Based on Bioassay Data ......... 8 

2.1.1 Reviewer’s Comments................................................................................ 8 

References..................................................................................................................................... 10 

Appendix A: IREP Input.............................................................................................................. 11 

Rocky Flats Plant Case PIID* 3 S. Cohen & Associates 
1.0 SUMMARY BACKGROUND INFORMATION 

This report presents the results of an independent audit of a dose reconstruction performed by the 

National Institute of Occupational Safety and Health (NIOSH) for an energy employee that 

worked at the Rocky Flats Plant for PIID*, from PIID*, to through PIID*. This period included 

the time when the Rocky Flats Plant produced plutonium triggers for nuclear weapons and 

processed weapons for plutonium recovery. 

As a result of the claimant’s employment as an PIID*, the worker may have experienced internal 

exposures due to the intake of particles of plutonium oxide in the workplace and outside 

environment, and external exposure from working in the vicinity of the production operations. 

The employee was diagnosed with lung cancer on PIID*. NIOSH determined that only a partial 

dose reconstruction was sufficient to produce a probability of causation of 50% or greater. As a 

result, dose reconstruction was limited to internal exposure to the lung and was based on missed 

dose from the employee’s urine analysis and lung-scan data, which resulted in a probability of 

causation (POC) value of 71.59%. 

Table 1 presents an overall summary of NIOSH’s dose reconstruction. 

Table 1. Summary of Internal and External Exposure as Estimated by NIOSH 

Appendix A 

Exposure Entry No.

Dose 

(rem) 

External Dose: 

 ▪ Photon Dosimeter Dose NC* — 

 ▪ Photon Missed Dose NC* — 

 ▪ Neutron Dosimeter Dose NC* — 

 ▪ Neutron Missed Dose NC* — 

 ▪ Occupational Medical NC* — 

 ▪ Onsite Ambient NC* — 

Internal Dose: 1 – 15 Mode = 123 

Max. = 245 

*NC = Not considered because exposure scenario was not needed to show causation 

1.1 AUDIT OBJECTIVES 

SC&A’s audit was performed with the following objectives: 

• To determine if NIOSH assigned doses that are consistent with monitoring 

records provided by the DOE and with the information contained in the CATI 

report 

• To determine if the dose reconstruction process complied with applicable 

procedures that include generic procedures developed by NIOSH and ORAUT, as 

well as data/procedures that are site-specific 

Rocky Flats Plant Case PIID* 4 S. Cohen & Associates 
• In instances when procedure(s) provide more than one option or require subjective 

decisions, determine if the process is scientifically defensible and/or claimant 

favorable 

In pursuit of these objectives, a two-step process is followed in this audit. The first step of this 

audit is to independently duplicate, and therefore validate, doses derived by NIOSH. This step of 

the audit process is not only contractually mandated under Task 4, but provides NIOSH and the 

Advisory Board with a high level of assurance that the SC&A reviewer understands which 

procedures, models, site-specific data, and assumptions NIOSH used to perform its dose 

reconstruction. The second step of the audit critically evaluates whether the methods employed 

by NIOSH are technically defensible, consistent with applicable procedures, and claimant 

favorable. 

Lastly, in compliance with the Privacy Act, this report makes no reference to the claimant’s 

name, SSN, address, or any personal data that might reveal the identity of the claimant. 

1.2 SUMMARY OF AUDIT FINDINGS 

An overview of SC&A’s audit findings for Case PIID* is provided in Table 2 in the form of a 

checklist. This checklist evaluates the data collection process, information obtained from the 

CATI interview, and all methods used in the dose reconstruction. When deficiencies are 

identified by the audit, such deficiencies are further characterized with regard to their impact(s) 

by means of the following definitions: (1) low means that the deficiency has only a marginal 

impact on dose; (2) medium means that the deficiency substantially impacts the dose, but is 

unlikely to impact the compensability of the case; and (3) high means that the deficiency 

substantially impacts the dose and may also impact the compensability of the case. A full 

description of deficiencies identified in the checklist is provided in the text of the audit that 

follows. 

Rocky Flats Plant Case PIID* 5 S. Cohen & Associates 
Table 2. Case Review Checklist __ 

CASE PIID* ASSIGNED DOSE: 123 rem POC: 71.59% 

Audit Response If No, Potential Significance No. Description of Technical Elements of Review YES N/A NO LOW1 MEDIUM2 HIGH3

A. REVIEW OF DATA COLLECTION: 

A.1 Did NIOSH receive all requested data for the DOE or 

AWE site from any relevant data source? T

A.2 Is the data used by NIOSH for the case adequate to 

make a determination with regard to POC? T

B. REVIEW OF INTERVIEW AND DOCUMENTATION PROVIDED BY CLAIMANT 

B.1 Did NIOSH properly address all work history 

dates/locations of employment reported by claimant? T

B.2 Did NIOSH properly address all 

incidents/occurrences reported by claimant? T

B.3 Did NIOSH properly address monitoring/ personal 

protection/work practices reported by claimant? T

B.4 Is the interview information consistent with data used 

for dose estimate? T

C. REVIEW OF PHOTON DOSES 

C.1 Was the appropriate procedure used for determining: 

C.1.1 - Recorded Photon Dose? T

C.1.2 - Missed Photon Dose? T

C.1.3 - Occupational Medical Dose? T

C.1.4 - Onsite-Ambient Dose? T

C.2 Did the DR properly account for all: 

C.2.1 - Recorded Photon Dose? T

C.2.2 - Missed Photon Dose? T

C.2.3 - Occupational Medical Dose? T

C.2.4 - Onsite-Ambient Dose? T

C.3 Is the recorded/assigned dose properly converted to the organ dose of interest for: 

C.3.1 - Recorded Photon Dose? T

C.3.2 - Missed Photon Dose? T

C.3.3 - Occupational Medical Dose? T

C.3.4 - Onsite-Ambient Dose? T

C.4 Is the organ dose uncertainty properly determined for: 

C.4.1 - Recorded Photon Dose? T

C.4.2 - Missed Photon Dose? T

C.4.3 - Occupational Medical Dose? T

C.4.4 - Onsite-Ambient Dose? T

D. REVIEW OF SHALLOW (i.e., 7 mg/cm2)/ELECTRON DOSES 

D.1 Was the appropriate procedure used for determining: 

D.1.1 - Recorded Shallow/Electron Dose? T

D.1.2 - Missed Shallow/Electron Dose? T

D.1.3 - Onsite Ambient Dose? T

D.2 Did the DR properly account for all: 

D.2.1 - Recorded Shallow/Electron Dose? T

D.2.2 - Missed Shallow/Electron Dose? T

D.2.3 - Onsite Ambient Dose? T

D.3 Is the recorded/assigned dose properly converted to the organ dose of interest for: 

D.3.1 - Recorded Shallow/Electron Dose? T

 

1 Low means that the deficiency has only a marginal impact on dose. 2 Medium means that the deficiency substantially impacts the dose, but is unlikely to impact the compensability of the case. 3 High means that the deficiency substantially impacts the dose and may also impact the compensability of the case. 

Rocky Flats Plant Case PIID* 6 S. Cohen & Associates 
CASE PIID* ASSIGNED DOSE: 123 rem POC: 71.59% 

Audit Response If No, Potential Significance No. Description of Technical Elements of Review YES N/A NO LOW1 MEDIUM2 HIGH3

D.3.2 - Missed Shallow/Electron Dose? T

D.3.3 - Onsite Ambient Dose? T

D.4 Is the organ dose uncertainty properly determined for: 

D.4.1 - Recorded Shallow/Electron Dose? T

D.4.2 - Missed Shallow/Electron Dose? T

D.4.3 - Onsite Ambient Dose? T

E. REVIEW OF NEUTRON DOSES 

E.1 Was the appropriate procedure used for determining: 

E.1.1 - Recorded Neutron Dose? T

E.1.2 - Assigned Neutron Dose? T

E.1.3 - Missed Neutron Dose? T

E.2 Did the DR properly account for all: 

E.2.1 - Recorded Neutron Dose? T

E.2.2 - Assigned Neutron Dose? T

E.2.3 - Missed Neutron Dose? T

E.3 Is the recorded/assigned dose properly converted to the organ dose of interest for: 

E.3.1 - Recorded Neutron Dose? T

E.3.2 - Assigned Neutron Dose? T

E.3.3 - Missed Neutron Dose? T

E.4 Is the organ dose uncertainty properly determined for: 

E.4.1 - Recorded Neutron Dose? T

E.4.2 - Assigned Neutron Dose? T

E.4.3 - Missed Neutron Dose? T

F. REVIEW OF INTERNAL DOSE: BASED ON HYPOTHETICAL MODEL 

F.1 Is the use of the selected hypothetical internal dose 

model appropriate, based on the likely POC value? T

F.2 Is the use of a hypothetical internal dose model 

appropriate/conservative, based on claimant’s 

available bioassay data,? 

T

F.3 Was the hypothetical dose value correctly derived? T

G. REVIEW OF INTERNAL DOSE: BASED ON BIOASSAY/IMBA 

G.1 Was the appropriate procedure (or section of 

procedure) used for determining likely (>50%), 

unlikely (<50%), or undetermined POC and 

compensability? 

T

G.2 Are bioassay data sufficiently adequate for internal 

dose reconstruction? T

G.3 Are assumptions pertaining to dates of uptake 

reasonable/conservative? T

G.4 Are critical parameters (e.g., solubility class, particle 

size, etc.) used for IMBA organ dose estimates 

appropriate? 

T

G.5 Are assigned uncertainties (measurement errors) for 

bioassay data (used as input to IMBA) appropriate? T

H. Total Number of Deficiencies and Their Combined Potential Significance 0 

___________________________ 

1

 Low means that the deficiency has only a marginal impact on dose. 2

 Medium means that the deficiency substantially impacts the dose, but is unlikely to impact the compensability of the case. 3

 High means that the deficiency substantially impacts the dose and may also impact the compensability of the case. 

Rocky Flats Plant Case PIID* 7 S. Cohen & Associates 
2.0 AUDIT OF ASSIGNED DOSES 

2.1 INTERNAL EXPOSURE TO THE LUNG FROM MISSED DOSE BASED ON 

BIOASSAY DATA

For dose reconstruction efficiency, NIOSH only calculated the missed internal dose from Pu-239 

intake during the period between PIID*. NIOSH modeled urine bioassay and lung-scan data to 

reconstruct the lung dose from Pu-239, since neither urine nor lung-scan data showed levels 

above MDA. 

NIOSH’s modeling approach was a two-step process that employed IMBA. By assuming a urine 

concentration at the MDA level, the IMBA code first back-calculated the inhalation intake for Pu 

that corresponded to the MDA level. For the second step, IMBA calculated the lung dose that 

corresponded to the inhalation quantity derived in the first step. 

For the time period of concern, NIOSH assumed the urine MDA value of 0.54 dpm/d ± 0.162, as 

defined in ORAUT-TKBS-0011-5. NIOSH further assumed a chronic intake and the insoluble 

form Type S for plutonium. Based on this model and parameter values, NIOSH derived doses 

cited in Appendix A of this report. For dose uncertainty, NIOSH assumed 1⁄2 maximum value as 

the mode of a triangular distribution with a minimum value of 0. The triangular distribution was 

used as input into the IREP causation calculation. 

NIOSH used a parallel approach for modeling lung dose based on the MDA for the lung scan. 

The assigned MDA for the lung scan was 77,203 ± 23,169 pCi. 

2.1.1 Reviewer’s Comments

SC&A reviewed the urine bioassay and lung scan records and verified that the dates of bioassays 

used for missed dose were within the timeframe specified by NIOSH. All DOE records were 

also reviewed to ensure that there was no detectable plutonium in the urine or the lung. 

The TBD was reviewed to verify that NIOSH used correct MDAs. It was determined that 

NIOSH correctly used the PIID*urine MDA for plutonium in Table 5.3.1.2-1 of the ORAUTTKBS-0011-5. To account for uncertainty, the TBD states that a standard deviation is the value 

cited in Table 5.3.1.2-1 divided by 3.3, which NIOSH did. SC&A could not exactly duplicate 

the MDA for lung scans, because the instructions in the TBD leave much interpretation to the 

individual dose reconstructor. The reconstructor has a choice in using a body index value. 

Values can be derived based on body weight or taken from the individual’s lung scan report, or a 

default value can be used. In addition, the TBD gives several americium-to-plutonium 

correction factors, based on assuming a range of typical concentration values for Am-241. The 

reconstructor must determine which factor is most appropriate. From what we could ascertain, it 

seemed that NIOSH used the lung scan Am-241 MDA from PIID* instead of PIID* (Table 

5.3.2.1.2-1of ORAUT-TKBS-0011-5). The 1973 MDAs are about 10 times greater than PIID* 

SC&A also verified the resulting maximum doses used in the IREP input (see Appendix A) by 

independently running the IMBA code. The use of a triangular distribution for the missed lung 

Rocky Flats Plant Case PIID* 8 S. Cohen & Associates 
dose with the mode at half the maximum value is claimant favorable. This suggests that the most 

likely dose is a factor of two below the detection limit. 

Using the Type S solubility for plutonium is also claimant favorable. This results in a slower 

lung clearance and a longer residence time for plutonium, which maximizes the dose to the lung. 

Because the calculated missed dose to the lung was sufficient to show causation, we agree that 

there was no need to reconstruct doses from the other exposure scenarios. This would only delay 

the dose reconstruction process unnecessarily. 

Rocky Flats Plant Case PIID* 9 S. Cohen & Associates 
REFERENCES 

ACJ & Associates and the UK National Radiological Protection Board. 2002. Integrated 

Modules for Bioassay Analysis, (IMBA), Phase 1, Software produced for NIOSH-OCAS as part 

of the EEOICPA program, Version 1.0.63, UK, November 2002. 

NIOSH Report of Dose Reconstruction Under the Energy Employee Occupational Illness

Compensation Program Act (EEOICPA). NIOSH ID: PIID*. 

OCAS-IG-002. 2002. “Internal Dose Reconstruction Implementation Guideline,” Rev.0.

National Institute for Occupational Safety and Health, Office of Compensation Analysis and 

Support, Cincinnati, Ohio, August 2002. 

ORAUT-TKBS-0011-5. 2004. “Technical Basis Document for the Rocky Flats Plant to be used 

for EEOICPA Dose Reconstruction,” January 12, 2004. 

Rocky Flats Plant Case PIID* 10 S. Cohen & Associates 
APPENDIX A: IREP INPUT

Deletions made to the following table -- hard copy labeled "#15 – Rocky Flats Plant" 

Rocky Flats Plant Case PIID* 11 S. Cohen & Associates