National Institute for Occupational Safety and Health

SEC-00247- Evaluation Recap

Superior Steel Co.

Megan Lobaugh, PhD, CHP

Health Physicist

Advisory Board on Radiation and Worker Health, 128th Meeting

Pittsburgh, PA

April 17, 2019
About Superior Steel Co. Site

Photo from USACE, 2018

 Carnegie, PA

• 5 interconnected buildings

 Uranium rolling for AEC

 Covered Period

• AWE: January 1, 1952 

through December 31, 1957

• Residual Radiation: January 

1, 1958 through present
Superior Steel Co. Processing Areas

From Myrick, 1981

From Myrick, 1981
SEC-00247 Petition for Superior Steel Co.

 83.13 (Form B) Petition Received May 1, 2018

– Petitioner-requested class: All workers who worked in any area at 

the Superior Steel Co. facility in Carnegie, PA, during the period from 

January 1, 1952 through December 31, 1957.

– (F.1) Basis: Radiation exposures potentially incurred by members of 

the proposed class were not monitored either through personal 

monitoring or through area monitoring.

 Petition qualified on July 19, 2018

– Qualified class: All atomic weapons employees who worked in any 

area at Superior Steel Co. in Carnegie, PA during the period from 

January 1, 1952 through December 31, 1957.
Superior Steel Co. Exposure Time

 AEC contract [AT(30-1)-1412] effective date is June 27, 1952 

 AEC contract end date is September 30, 1957 

– Evidence that the fission material accounting station authority was 

withdrawn on November 27, 1957

 AEC cost-plus-fixed-fee contract was for intermittent, on-demand rolling

– Payments through fiscal year 1957 totaled $356,849 

 CATI information tells us overtime work was common
Radiological Sources at Superior Steel Co.

 Majority of AEC rolling campaigns were with natural uranium metal

 1 AEC rolling campaign included 6 slabs of 1.5% enriched uranium metal

 Since the Superior Steel Co. operations were after 1952, uranium metal 

could be recycled

 1 commercial, small-scale rolling campaign with 700 pounds of thorium 

metal
Monitoring Data AvailableInternal Exposure at Superior Steel Co.

 Personal Monitoring: No in vitro or in vivo results and there is no 

indication of internal dosimetry monitoring program 

 Area Monitoring: Four campaigns of air monitoring (e.g., BZ and area) 

performed by AEC Health and Safety Laboratory (HASL) during uranium 

rolling:

– May 13, 1953 

– August 3, 1953 

– May 9, 1955 

– September 19, 1955
Monitoring Data and Information AvailableExternal Exposure at Superior Steel Co.

 Personal Monitoring: No external dosimetry results and there is no 

indication of external dosimetry monitoring program

 Area Monitoring: No indication of area external dose monitoring program

 Information is available to NIOSH about the Superior Steel Co.’s AEC 

contract, radiological material licensing, processes, and the material 

processed
Dose Reconstruction Feasibility Conclusion

 NIOSH has sufficient air data and process information to bound internal 

and external dose from AEC uranium metal rolling operations

 NIOSH has sufficient process information to bound internal and external 

dose from the small-scale, commercial thorium metal rolling operation

 NIOSH Site Profile for Superior Steel Co. (effective date 2005) will be 

updated with the additional information captured and reviewed in this 

evaluation
Evaluation of Petition Basis- Internal Monitoring

 “Individual uranium urinalysis data are unavailable for Superior Steel workers and 

none are known to exist.” (ORAUT-TKBS-0034)

– When personal internal monitoring data are unavailable, NIOSH uses air 

monitoring data from worker breathing zones and work areas, in accordance 

with NIOSH’s OCAS-IG-002, Internal Dose Reconstruction Implementation 

Guideline

– Sufficient site-specific air monitoring data and process data to calculate 

estimates of worker internal uranium doses with sufficient accuracy

– Airborne mass loading calculations using available uranium process air 

monitoring data to estimate worker internal thorium doses
Evaluation of Petition Basis- External Monitoring

 “No external dosimetry results are available for Superior Steel employees.”

(ORAUT-TKBS-0034)

– When personal and area external monitoring data are unavailable, NIOSH uses 

workplace information (e.g., source term, process) to estimate dose, in 

accordance with NIOSH’s OCAS-IG-001, External Dose Reconstruction 

Implementation Guideline

– Sufficient applicable site-specific information, using the methods of BattelleTBD-6000, to model potential external uranium exposures

– Model thorium metal related exposures in accordance with the methods 

presented in Battelle-TBD-6000 using MCNP
Feasibility Findings for SEC-00247 Superior Steel Co. 

January 1, 1952 to December 31, 1957

Source of Exposure Dose Reconstruction Feasible

Internal Yes

Uranium Yes

Thorium Yes

External Yes

Uranium Yes

Thorium Yes

Occupational Medical X-rays Yes