Office of Compensation Analysis and Support 

Program Evaluation Report

Document Number: OCAS-PER-031 

Effective Date: 12/18/2007 

Revision No. 0 

Y-12 TBD Revisions Page 1 of 2 

Author: Signature on file Date: 12/18/2007_ Dave Allen, HP Team Leader 

Approval: Signature on file Date: 12/18/2007 _ J.W. Neton, Associate Director for Science 

Supersedes: None 

RECORD OF ISSUE/REVISIONS 

ISSUE 

AUTHORIZATION 

DATE 

12/18/2007

EFFECTIVE 

DATE 

12/18/2007 

REV. NO. 

0 

DESCRIPTION 

New document to determine which 

previously completed claims require 

evaluation for the effect of revising the 

Y-12 Plant TBD. 

1.0 Description

The Y-12 National Security Complex Technical Basis Document (ORAUT-TKBS-0014) 

has been revised several times. The TBD contains six separate sections each pertaining 

to a specific part of dose reconstruction. Technical Information Bulletins (TIB) are also 

utilized in dose reconstruction. Many of the revisions only corrected typographical errors 

or clarified language. Some revisions were made as the result of a Special Exposure 

Cohort (SEC) designation for specific classes of employees at the site. Methods outlined 

in the latest revision of these documents were reviewed against previous methods to 

determine if any previously completed dose reconstruction would result in an increased 

dose using current methods. The review was limited to any increase rather than an 

overall increase. Therefore, since changes that would cause dose to decrease were not 

reviewed, it is possible a new dose reconstruction would result in an overall decrease in 

dose even if it is determined that a new dose reconstruction is warranted. 

2.0 Issue Evaluation

Several changes to Y-12 documentation can be classified as “phased implementation”. 

This is an approach of issuing a TBD with some sections marked “reserved” or specific 

issues not covered in order to allow the completion of claims unaffected by that aspect of 

dose reconstruction. Internal and external co-worker TIBs are examples of these. Claim 

for which a co-worker model was necessary could not be completed until these models 

were available. As such, issuing these documents does not represent an increase in dose 

for any previously completed claims. 

After evaluating the Y-12 documentation, one issue did arise that could increase the dose 

estimate for some claims. The equilibrium ratio for Th-228/Th-232 was changed from 

assuming 100% equilibrium to assuming 80% equilibrium. Incorporating this change 
Office of Compensation Analysis and Support

Document Number: OCAS-PER-031 Program Evaluation Plan 

Effective Date: 12/18/2007 Revision No. 0 Page 2 of 2 

would increase the dose estimate for claims containing a thorium intake determined from 

chest count data. This change was included in revision 1 page change 2 (Rev. 1 PC-2) of 

the internal dose section of the Y-12 TBD (ORAUT-TKBS-0014-5). This change was 

issued on 1/12/2006. 

3.0 Plan for Resolution or Corrective Action

There were 693 Y-12 claims completed prior to 1/12/2006 with a probability of causation 

below 50%. The dose reconstruction methodology of each will be reviewed to determine 

if a new dose reconstruction is necessary to determine if the revisions increase the dose 

estimate. The criteria for making this determination are: 

1. Any of the claims assigned a thorium intake based on chest count data will 

require a new dose estimate. 

NIOSH will review these dose reconstructions to determine if they meet the criterion 

listed above. NIOSH will provide DOL with the list of 693 claims as well as a 

determination on each claim as to whether a new dose estimate is required. 

Documentation for each claim not requiring a new dose reconstruction will provide the 

basis for that determination.