Office of Compensation Analysis and Support 

Program Evaluation Report

Document Number: OCAS-PER-013 

Effective Date: 8/13/2007 

Revision No. 0 

Evaluation of the Impact of Changes to the Isotopic Ratios in for the 

Paducah Gaseous Diffusion Plant Page 1 of 3 

Author: Signatue on file Date: 8/13/2007 Dave Allen, HP Team Leader 

Approval: Signature on file Date: 8/13/2007 J.W. Neton, Associate Director for Science 

Supersedes: None 

RECORD OF ISSUE/REVISIONS 

ISSUE 

AUTHORIZATION 

DATE 

8/13/2007

EFFECTIVE 

DATE 

8/13/2007 

REV. NO. 

0 

DESCRIPTION 

This document provides a list of previously 

completed claims that are potentially affected 

by a revision to the Paducah isotopic ratios.

1.0 Description

On October 25, 2006, Revision 01 of ORAUT-TKBS-0019-51, Occupational Internal 

Dose, was issued as part of the biennial review process. During the biennial revision of 

this TBD section, the information provided in the existing document was evaluated to 

ensure that the published isotopic ratios for transuranic (TRU) radionuclides met the 

criteria of providing either an accurate or a bounding dose estimate. The results of the 

evaluation indicated that the current ratios did not meet that goal. Information found in 

existing references (particularly PACE and the University of Utah, 20002

; BJC, 20003), 

as well as that found in a new reference4

, was evaluated against the ratios in the existing 

site profile section. Based on this evaluation, new TRU isotopic ratios were developed 

and are included in the TBD as Tables 5-2 and 5-2a in the revised document. 

On November 7, 2006 Revision 01 of ORAUT-TKBS-0019-45, Occupational 

Environmental Dose was issued. A revaluation of the source data for ORAUT-TKBS0019-5 led to a revision to the TRU isotopic ratios (relative to uranium) for estimating 

dose from these radionuclides. In addition, the authors have been able to categorize these 

ratios according to specific processes and periods as described below in conjunction with 

ORAUT-TKBS-0019-5. 

On January 11, 2007 and April 4, 2007 page changes 1 and 2 respectively of ORAUTTKBS-0019-5 were issued. These changes corrected typographical errors and omissions 

in revision 1 but did not affect any dose assignments. On April 23, 2007 a similar type of 

page change was issued for ORAUT-0019-4. 
Office of Compensation Analysis and Support

Document Number: OCAS-PER-013 Program Evaluation Plan 

Effective Date: 8/13/2007 Revision No. 0 Page 2 of 3 

2.0 Issue Evaluation

The new isotopic ratios will provide a bounding, yet plausible estimate of internal dose 

due to TRU radionuclides present in recycled uranium. The new data is categorized 

according to specific plant areas shown below for both pre-1983 and post-1983 

operations: 

Pulverizer, Ash Handling, Green Salt Production 

Converter Salvage Line 

99Tc/237Np Recovery 

Balance of Plant (cascade operations/maintenance, etc) 

In addition, ratios for 241Am and plutonium isotopes (238Pu, 240Pu, 242Pu, and 241Pu) were 

added. These changes will have the effect of increasing the dose estimates for claimants 

who worked in these operations from 1953 through the end of enrichment operations, 

with the exception of Balance of Plant Operations which will have lower dose estimates. 

3.0 Plan for Resolution or Corrective Action

An initial selection of claims was based on the following search criteria: 

1. Probability of Causation (POC) less than 50% 

2. Dose Reconstructions completed prior to November 7, 2006. 

These criteria were used to produce a list of 734 potentially affected claims. NIOSH will 

provide this list to DOL and request these claims be returned for a new dose 

reconstruction. The new dose reconstruction will be completed using all the current 

methodology which will account for any other changes affecting these claims. 
Office of Compensation Analysis and Support

Document Number: OCAS-PER-013 Program Evaluation Plan 

Effective Date: 8/13/2007 Revision No. 0 Page 3 of 3 

4.0 References

1. ORAUT (Oak Ridge Associated Universities Team), ORAUT-TKBS-0019-5, 

Technical Basis Document for the Paducah Gaseous Diffusion Plant – 

Occupational Internal Dose, Rev 02, April 4, 2007. 

2. PACE (Paper, Allied Industrial, Chemical and Energy Workers International 

Union) and University of Utah, Exposure Assessment Project at the Paducah 

Gaseous Diffusion Plant, December 2000. 

3. BJC (Bechtel Jacobs Company) Recycled Uranium Mass Balance Project 

Paducah Gaseous Diffusion Plant Site Report, BJC/PGDP-167, March 5, 2000. 

4. Hightower, J.R., L.R. Dole, D.W. Lee, G.E. Michaels, M.I. Morris, D.G. 

O’Conner, S.J. Pawel, R.A. Schmoyer, L.D. Trowbridge, and V.S. White, 

Strategy for Characterizing Transuranics and Technetium contamination in 

Depleted UF6 Chlinders, ORNL/TM-2000/242, UT-Battelle, Oak Ridge National 

Laboratory, October 2000. 

5. ORAUT (Oak Ridge Associated Universities Team), ORAUT-TKBS-0019-4, 

Technical Basis Document for the Paducah Gaseous Diffusion Plant – 

Occupational Environmental Dose, Rev 02, April 23, 2007.