Priority Issues for demonstrating feasibility of dose reconstruction for MCW 

Destrehan Street workers for the time period of 1949 to 1957: List of Tasks 

Developed by the ABRWH 

July 6, 2005 

The following is a list of tasks to be completed by NIOSH and delivered to the ABRWH 

workgroup and SCA, Inc. for resolution. To allow for an adequate amount of time for 

SC&A/NIOSH/Board to complete comment resolution by August 23 the following 

schedule is set forth: 

•	 Workgroup conference call for status report and task clarification by July 26 

•	 NIOSH will provide a draft report on the following tasks in consultation with 

SCA by July 31 

•	 Work Group meeting between July 31 and August 8 

•	 SCA to review the NIOSH response to the tasks and issue report to Board by 

August 16 (1 week before Board meeting) 

•	 Work group conference call for comment resolution between August 16 and 

August 22 

List of Tasks 

1.	 Handling of Raffinate exposures 

a.	 NIOSH should specify the radionuclide ratios (Ra-226, Th-230, Ac-227, 

Pa-231) for all ore processing (including non-pitchblende ores) 

b.	 NIOSH should specify the radionuclide ratios for K-65 uranium extraction 

(including processing steps and filtration steps) 

c.	 NIOSH should specify how ratios will be applied by job title (including 

roving workers and cases where no job title are available) 

d.	 NIOSH should specify approach for estimating intake when any 

combination of urine, air sampling and breath radon data is available. In 

this context NIOSH should consider the reliability of breath radon for 

determining Ra-226 intakes. 

2.	 Handling of Radon exposures 

a.	 NIOSH must resolve whether sufficient radon data is available to 

determine job specific radon exposures 

b.	 NIOSH must specify approaches for handling job specific radon values 

c.	 NIOSH / SCA must further discuss and if possible resolve organ doses per 

unit intake of radon 

3.	 Application of correction factors for external doses to organs 

a.	 NIOSH must specify the approach to be used to determine organ specific 

and job specific geometry assumptions to be used in dose reconstructions 
4.	 Assessment of intermittent incident exposures 

a.	 NIOSH should determine, for a given set of bioassay data, what the 

approach to estimating cumulative intake will be when there are 

significant / infrequent incidents (e.g. dust bag ruptures, overflow of 

thorium solution) given the guidelines in the site profile Rev. 1 section 

6.1, item 1. 

5. Specification of dose reconstruction methodology for un-monitored workers 

a.	 NIOSH needs to outline scientifically defensible approaches to be used for 

conducting dose reconstructions for un-monitored workers (e.g. secretarial 

workers, maintenance mechanics, plant 1 and 2 decommissioning workers, 

SLAPS workers) including specific assumptions regarding radionuclide 

mixture 

6.	 Example dose reconstructions for representative cases 

Representative cases should include the following: 

a. Example internal dose reconstruction for plant 6 subject involving K-65 residues 

processing for U extraction (where urine, air and breath radon are available) for selected 

metabolic and non-metabolic organs. 

b. Example internal dose reconstruction for plant 6 case involving K-65 residues 

processing for U extraction (where urine, air data are available but no breath radon) for 

selected metabolic and non-metabolic organs. 

c. Example internal dose intake estimate for plant 7 Thorium extraction worker (1955-

1957).