Hangar 481

Special Exposure Cohort 

Petition Evaluation Report Update

Samuel E. Glover, PhD

Research Health Scientist

National Institute for Occupational Safety and Health

Division of Compensation Analysis and Support

February 2012

Oakland, CA
Hangar 481 Site History

 Located at Kirtland Air Force Base in Albuquerque, 

New Mexico

 Ross Aviation, with operations based at Hangar 481 

during the covered period, was under contractual 

agreement with DOE

• Provided air transportation of personnel and equipment as 

using government owned aircraft at government owned 

facilities associated with DOE operations at the Sandia 

National Laboratory in Albuquerque, New Mexico

 Transported equipment—included packages 

containing radioactive materials associated with 

atomic weapons programs
Petition Overview

 February 27, 2009: 83.13 petition received

 September 8, 2009: petition qualified for evaluation

 December 18, 2009: Evaluation Report issued

 February 2010: Evaluation Report presented at Advisory 

Board meeting

• Delay requested by petitioner until Freedom of Information Act 

(FOIA) material could be provided

 July 2010: FOIA completed (DOE and NIOSH) 

 September 23, 2010: Revised Evaluation Report issued 

(updated photo of Hangar 481)
Petition Overview—cont.

 November 2010: Evaluation Report re-presented at 

Advisory Board meeting

 November 3, 2010 Petitioner submits FOIA request for 

information which was not in NIOSH’s possession at the 

time

 January 21, 2011: CDC FOIA office responds to the 

November 3 request explaining that materials will not be 

in our possession for some time as they are being 

reviewed by the Department of Energy and that he 

should resubmit the request in June 2011 
Petition Overview—cont.

 January 2011: NIOSH and petitioners tour Hangar 481 

and provided a list of follow-up questions to Office of 

Secure Transport (OST) (DOE)

 June 2011: Responses provided by OST to NIOSH

 August 2011: Addendum to the Evaluation Report issued 

for Hangar 481

 August 2011: Evaluation report re-presented at Advisory 

Board meeting 

 August 2011: Petitioner requests extension of the 

matter from the Board so that a FOIA request could be 

submitted
Petition Overview—cont.

 October 2011: Petitioner submits an official FOIA 

request

 November 2011: Petitioner withdrew FOIA request

 February 2012: NIOSH provides brief summary to 

the Advisory Board for their consideration

 NIOSH believes that all concerns expressed by the Advisory 

Board were addressed 
Summary of External Dose Feasibility

 External dose records exist for many Ross Aviation 

personnel and the REIRS reported data have been 

verified using Eberline data from 1990-1994

 Data from the 1994 REIRS report was found to be 

incorrectly entered into the database (lifetime total 

instead of annual dose) and has been corrected in 

this addendum and DOE has been notified

 The individual results of these records or use of the 

highest dose received by monitored personnel, 

adequately bounds unmonitored worker external 

dose
Summary of External Dose 

Feasibility–cont. 

 Data from 1996 was not included in REIRS (covered 

period ends February 29, 1996)

• NIOSH will use the highest annual dose for previous years 

for this 2-month period

 NIOSH will use the highest dose received in the 

entire year previously to bound any external dose 

for all employees

 The circumstances and locations related to the 

pilots’ lockers and radiographic activities (done only 

during off hours) provide the only available 

explanation for elevated personnel dosimeter 

readings as described by the petitioner
Summary of External Dose 

Feasibility–cont. 

 There is no credible potential for neutron exposures

 Potential doses from off-hour radiographic testing 

would be included in the reported personal 

monitoring data

 Ambient environmental external doses are included 

by using the existing personnel external monitoring 

data

 X-ray examinations are not included because 

medical X-rays were not performed on-site at 

Hangar 481
Summary of Internal Dose Feasibility

 No radioactivity was stored or handled at the 

Hangar 481 facility

 Radioactive materials handled by workers at 

Hangar 481 were in sealed DOT-compliant 

containers and monitored in accordance with 

DOT regulations to verify radiation and 

contamination levels on package exteriors

• Results of available radiological surveys performed on 

the packages and in the transport aircraft support this 

premise
Summary of Internal Dose 

Feasibility—cont. 

 Based on the available information on the 

radiological program and potential for internal 

exposure sources, NIOSH concludes that internal 

radiological exposures to Ross Aviation 

employees resulting from services rendered for 

the DOE at Hangar 481 are unlikely to have 

occurred

 Sandia National Laboratory, being an adjacent 

facility, was used to provide a bounding estimate 

of the dose from ambient environmental 

internal dose during the covered period
Feasibility Summary

Feasibility Findings for SEC-00139

Source of Exposure

Dose Reconstruction 

Feasible

Dose Reconstruction 

NOT Feasible

Internal

X

External

 - Beta-Gamma X

 - Neutron N/A

 - Occupational 

 Medical X-ray

N/A