SUPERIOR STEEL CO.

SEC PETITION SEC-00247

PRELIMINARY REVIEW

Meeting of the Advisory Board on Radiation and Worker Health

April 2019
Site Information

 Located in Carnegie, PA (outside of Pittsburgh)

 Metal processing facility hired by AEC because it was one of only a 

few companies identified with the technical expertise to roll and clad 

metal strip plate

 Cost-plus-fixed fee contract for intermittent, on-demand rolling

 Covered years:

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Petition-Related Dates

 Petition received on May 1, 2018

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. 

Basis:

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

none are known to exist.” 

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

 Petition qualified for evaluation July 19, 2018

 Qualified class: 

All atomic weapons employees who worked in any area at Superior Steel Co. in 

Carnegie, Pennsylvania, during the period from January 1, 1952 through 

December 31, 1957. 

 NIOSH Petition Evaluation Report issued November 16, 2018

 Board discussed at December 12–13, 2018, meeting

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Data Reviewed By SC&A

 Site Research Database

 Health and Safety Laboratory (HASL) monitoring studies

 United States Army Corps of Engineers Preliminary Assessment 

study

 Thorium licensing communication

 CATI reports

 Superior Steel TBD (ORAUT-TKBS-0034, Rev. 00 PC-1)

 TBD-6000

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Radiological Exposure Sources at Superior Steel Co.

Uranium

 Uranium slabs heated in salt 

bath, rolled numerous times, 

finished cut, and allowed to cool

 Majority natural uranium

 May have been RU

 One known campaign of 1.5% 

enriched uranium

 4 HASL air monitoring studies

 ~17 BZ results

 ~144 process/general air samples 

Thorium

 Licensed to possess 

700 pounds

 Evidence of test rolling

 Commercial client (i.e., non-AEC)

 Expanded to unlimited

 No evidence of additional rollings, 

receipt of materials, or work orders

 No evidence of thorium 

contamination found in cleanup 

efforts

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Important Dates
Challenges

 No worker monitoring (both internal and external)

 Air sampling done on limited occasions

 Original contract documentation destroyed

 Minimal information regarding thorium

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NIOSH Approach to Internal Dose from Uranium

 500 hours rolling mill time per year

 Established via contract annual billings 

 Use Vulcan Crucible Steel billing rate per hour

 Air concentrations established from 4 HASL studies

 U-234 including RU contaminates

 Split into a pre- and post-May 9, 1955, rolling

 Man-cooling fans installed at unknown date between August 1953 and 

May 1955 rollings

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HASL Air Sampling Data (bin width of 200)

Distribution of 

air monitoring 

data similar 

for 1953 and 

1955
HASL Air Sampling Data (zoomed in with bin width of 25)

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Distribution of 

air monitoring 

data similar for 

1953 and 1955
HASL Air Sampling Data by Survey

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May 1955 

distribution trends 

lower; however, 

gains are lost in 

September 1955 

sampling 
HASL Air Sampling Data by Survey (zoomed in)

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May 1955 

distribution trends 

lower; however, 

gains are lost in 

September 1955 

sampling 
NIOSH Approach to Internal Dose from Thorium

 Th-232 and daughters in secular equilibrium

 Single 10-hour rolling

 Air concentrations based on mass loading approach

 Use U milling air concentration determined from air monitoring 

results

 Similar approach to Bridgeport Brass but assumes Th mass loading 

equal to U mass loading 

 Resuspension remainder of 1956‒1957

 1E-5 /m resuspension factor 

 Source term depletion based on ORAUT-OTIB-0070

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NIOSH External Uranium Exposures

 500 hours rolling per year using Battelle-TBD-6000 default 

worker assumptions

 Direct rolling

 Submersion

 500 hours storage

 2,000 hours post-rolling

 Direct exposure 

 Submersion

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NIOSH External Thorium Exposures

 10 hours rolling using Battelle-TBD-6000 guidance

 Direct rolling

 Submersion

 190 hours storage

 April 30,1956, through end of operations post-rolling

 Direct exposure 

 Submersion

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Occupational Required X-ray Examinations

 No evidence of examinations

 No CATI statements indicating examinations

 NIOSH intends to assign pre-employment, annual, and 

termination medical X-ray doses for all employees during the 

AWE operational period 

 ORAUT-OTIB-0006 

 Consistency with other AWEs?

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