Hooker Electrochemical

Special Exposure Cohort 

Petition Evaluation 

Update

Henry A. Anderson, M.D.

Chairman

Uranium Refining AWE Work Group

December, 2011

Tampa, FL
Background 

 Hooker Electrochemical classified as 

Atomic Weapons Employer (AWE) fafrom 1943 to 1948 

 Residual contamination period throu

1976 

 Primarily produced non-radioactive 

chemicals (P-45) for the MED 

 Concentrated uranium-contaminated 

magnesium fluoride slag using wastehydrochloric acid from P-45 process 
Background

(Continued) 

 Building was constructed to perform 

concentrating operation; Building wcompleted on July 11, 1944 

 Most slag-handling conducted outdo P-45 operations ended January 15, 19 Concentration of incoming material w

0.2% uranium by mass 

 Material was concentrated to 1% to 2
Process at Hooker

 C-2 slag was received in 500-pound

barrels from Electro Metallurgical

• The barrels were dumped onto a convey

that carried slag to one of three digest ta

• Waste HCL from the P-45 plant was adde

the tank and diluted to a ph of 4.0 

• The tank was agitated for 20 hours • Once in two days the liquid was decante

more HCL was added. 

• At the end of the digestion, the slurry wa

neutralized with lime and pumped to a fipress 

• The filtered material was rebarreled 
Special Cohort Petition 

Bases and Concerns

 Unmonitored workers 

• Petition presented an affidavit 

indicating there was no internal or external radiation monitoring at Ho

• No indication of monitoring was fo

in records. 
Hooker TBD

 Dose reconstruction methodology wa

originally described in Appendix AA Battelle-TBD-6001 

 Hooker TBD replaced Appendix AA a

changed proposed method of dose reconstruction, including revising approach to use of surrogate data fointernal dose 
Petition Timeline Overview

 Submitted on March 6, 2009 – propose

was for the “furnace room” 

 Proposed finding sent to petitioner 5/1

– not qualified for evaluation 

 Petitioner revised proposed class 9/26 Qualified for evaluation 10/16/ 2009  Evaluation Report issued on 5/3/2010  AWE Workgroup assigned review 
Petition Timeline Overview

(Continued) 

 8/2011 AWE Workgroup recommends  8/2011 ABRWH Board tables motion 

• requests expanded paper on surrogate data assess• Allow more time for petitioner review 

 AWE Workgroup tasks SC&A to prepa

whitepaper – Thurber Sept 22 memo 

 AWE Workgroup meets 11/21/2011 
Internal Exposure Modelin

Use of Surrogate Data

 Based on 18 air samples for handling C

at Electromet, Fernald, and Mallinckrod

 Used upper 95th percentile of air samp

results 

 More than 70% of air samples are BZ  For residual period deposition/ resuspe

model used with resuspension factor o06/m and no source term decay 
External Exposure Modelin

 Exposure to workers handling slag in 

wooden barrels based on MCNPX calculations 

 Exposure to workers from surface 

contamination based on MCNP calculations of slag dust settling from 95th percentile air concentrations 

 External doses rates for residual per

same as for operating period 
Work Group Review

Use of Surrogate Data

 In May 2011, NIOSH issued a white pa

evaluating the use of surrogate data Hooker against ABRWH criteria. 

 The Work Group requested that NIOS

revise the white paper to fully documsources of air samples, and requesteSC&A review the revised white paper
Work Group Review 

Use of Surrogate Date

(Continued) 

 SC&A reviewed the revised NIOSH w

paper and concluded that: 

“Based on our review, we believe that NIOSH ha

addressed the ABRWH surrogate data criteria in 

appropriate manner, and that the use of surrogat

at Hooker is consistent with the Board criteria. Us

the selected surrogate data will result in plausible 

bounding estimates for internal exposures at Hoo
Work Group Review 

Use of Surrogate Date

(Continued) 

 Thurber Sept 22, 2011 memo 

• SC&A review includes an expanded group of 

samples – 67-72 vs NIOSH 18 

• 95% upper confidence limit in the range of N

– NIOSH 806 dpm/m3 SC&A 555 - 759 dpm/m3 

• The 95th percentile is not particularly sensitive 

reasonable but differing technical judgments sample selection 
Work Group Recommendatio

 After 11/17 meeting discussions, Wo

Group continues to believe surrogate use proposed follows ABRWH criteri

 Doses for workers at Hooker can be 

plausibly reconstructed using informin the Hooker TBD (revised June 201

 Work Group continues to recommend 

Petition SEC-0014 be rejected. 
Remaining Issues for ABRW

 Is proposed use of surrogate data 

appropriate? 

 Is the Fernald monitoring data reliabl Petitioners have requested ABRWH B

defer decision until after petitioners receive response to FOIA request