Joslyn Manufacturing and Supply Co.

Special Exposure Cohort 

Petition Evaluation Report Addendum

Samuel Glover, PhD

Research Health Scientist

National Institute for Occupational Safety and Health

Division of Compensation Analysis and Support

TBD-6000 Work Group 

January 16, 2014
Brief Site Description

 Joslyn is listed as an Atomic Weapons Employer 

for the Atomic Energy Commission (AEC) from 

March 1943 to 1952

 Principal operations included the machining and 

rolling of uranium rods with limited thorium 

machining operations

 Joslyn was the primary commercial rolling 

facility for the AEC prior to Simonds Saw and 

Steel
Petition Overview

 Summary of Actions to Date

• December 2012 NIOSH and the Advisory Board 

recommended to add a class to the SEC for all AWE 

employees who worked at Joslyn for the period March 

1943 through December 31, 1947

• NIOSH proposed at that time that it could perform dose 

reconstruction beginning January 1, 1948 based on TBD6000 methods

• Advisory Board withheld its judgement on the 1948-1952 

period and requested SC&A to prepare a report

• SC&A generated a report which was summarized into 11 

issues for resolution (December 18, 2013 Issue Resolution 

Matrix)
Background 

 Joslyn Manufacturing and Supply Company is located in 

Fort Wayne, IN with a long history of producing 

stainless steel

 Joslyn participated in a number of radiological 

operations for the Manhattan Engineer District (MED) 

and later the AEC including hot rolling, quenching, 

straightening, cooling, grinding, waste burning, and 

abrasive cutting of natural uranium billets into metal 

rods
Background 

 Much of the early work at Joslyn (pre-1948) was related 

to production of uranium for the Hanford site

 Also used for numerous experiments to develop 

procedures for rolling uranium metal for use in nuclear 

reactors

 Performed rolling operations associated with testing 

uranium metal rods at the Chalk River reactor in Canada

 Prepared uranium metal for the British government
Background
Sources of Exposure

 Principal source for workers included the inhalation and 

ingestion of natural uranium oxide from the production and 

shaping of uranium metal rods

 Joslyn was a hand-operated shop, rods were manually 

reinserted into the mill the required number of times and 

then dragged to the next process

 Joslyn operated three rolling mills (18 inch, 12 inch, and 9 

inch) which were co-located and used for various operations 

simultaneously

 Rolling of uranium was conducted on rollers which had 

water-cooled bearings which produced steam and high 

levels of contamination
Sources of Exposure

 Additional machining and preparation steps (i.e. centerless 

grinding, cutting, heat treating and quenching, and 

threading) were carried out on uranium metal prepared at 

Joslyn as well as from other facilities

 Billets were stored onsite for relatively long periods of time 

in a storage area

 Uranium waste was noted to be collected and burned 

outside

• Worker interviews supported the burning of waste

• Document reviewed describes an offsite explosion of a drum of 

uranium metal from Joslyn which had not been properly treated
Approximate Quantities of Uranium 

Processed at Joslyn

Uranium Work at Joslyn

six month interval

1st half 1943

2nd half 1943

1st half 1944

2nd half 1944

1st half 1945

2nd half 1945

1st half 1946

2nd half 1946

1st half 1947

2nd half 1947

1st half 1948

2nd half 1948

1st half 1949

2nd half 1949

1st half 1950

2nd half 1950

1st half 1951

2nd half 1951

1st half 1952

2nd half 1952

pounds of uranium processed

0

100000

200000

300000

400000

500000

600000

700000
Internal Dose Monitoring Programs 

and Data Availability

 No routine air monitoring or bioassay program

 Limited air samples taken on three different occasions 

(December 1943, May 1944, October 1951)

• Very limited in scope

• Mostly General Area (GA) samples

• Early data taken using equipment (electrostatic precipitator) which 

would not be comparable to HASL equipment

• Much more substantial study performed January 8, 1952: 

HASL conducted a time weighted average study of various 

production operations at Joslyn
So Why Add Seven Months? 

 NIOSH had previously recognized that the TBD-6000 approach needed 

validation for specific practices and methods used at the Joslyn facility 

performed under MED supervision

 Extensive data collected in 1952 which was shown to be bounded by a TBD-6000 

approach: How far back can NIOSH justify that they represent the conditions and 

practices at the site?

 NIOSH recognizes that practices and standards were evolving rapidly 

during the period 1943-1948.

 For Joslyn, the same oversight continued through the high production rolling 

period (until the end of July 1948)

 Operations after July of 1948 are clearly done under the auspices of the AEC 

(including contracts and presence of AEC officials)

 The tie to AEC (and hence HASL) provides consistency with monitoring 

procedures, representativeness of sampling, 
So Why Add Seven Months?

 Joslyn had three closely co-located rolling mills (see earlier 

diagram)

 The pre-August 1948 practices include documented rolling of 

multiple rods simultaneously on the same or adjacent mills whereas 

the 1952 study was done one station at a time.

 For early 1948: this practice was needed to handle the nearly 

600,000 lbs of uranium rods that were processed in 42 operating 

days (January to July 31, 1948)

 NIOSH does not feel that that the data collected in 1952 are directly 

comparable to this high production phase which required different 

operational practices
So Why Add Seven Months?

 Most of the rolling days (and the only days with substantial 

rolling efforts) in 1949 and 1950 were in support of the AEC 

at the Chalk River reactor Canada (alpha phase uranium 

dimensional stability)

 Required careful temperature control 

 Represented smaller efforts (approximately 30 tons in both 1949 and 1950)

 These two efforts represent were specifically done using only the 18 inch 

rolling mills 

 The 18 inch rolling mill was shown in the 1952 study to have substantially 

lower air concentration levels that the 9 inch mill.

 Previous electrostatic precipitation air sampling also showed the 9” mill 

produced much higher air concentrations than the other mills
Post July 1948 Internal Dose

 Beginning with August 1, 1948 NIOSH proposes to use the data from 

TBD-6000 and known rolling days to determine internal and external 

dose

 Dose reconstruction approach summarized in a white paper (currently in 

classification review)

 Standard approach to medical X-ray dose using OTIB-0006

 TBD-6000 tabulated data converted from per calendar day to per rolling 

day exposures for ingestion and inhalation (assuming 250 work days per 

year)

 In addition to rolling operator, NIOSH will include uranium machining as 

a method using TBD-6000 to assess the considerable amount of 

machining operations conducted during the Joslyn operational period 
Proposed Class

“All Atomic Weapons Employees who worked in 

any buildings/area owned by the Joslyn 

Manufacturing and Supply Co. in Fort Wayne, 

Indiana, from March 1, 1943 through July 31, 

1948, for a number of work days aggregating at 

least 250 work days, occurring either solely 

under this employment or in combination with 

work days within the parameters established for 

one or more other classes of employees included 

in the Special Exposure Cohort.”
Joslyn SEC Petition 200

 Why the class?

• Workers were potentially exposed to uranium and 

thorium who were not monitored nor does a suitable 

dose reconstruction method exist prior to 1948 at Joslyn.

• Decision was based on lack of adequate biological 

monitoring data, sufficient air monitoring information, 

and differences in operational characteristics from other 

metal working (no appropriate surrogate data exists)
Joslyn SEC Petition 200

 Why everyone?

• Based on reports by the AEC and facility layout, the 

process areas were broadly distributed and controls for 

preventing movement in these areas was not enforced

 Why stop in July 1948?

• NIOSH feels that the surrogate data from TBD-6000 

coupled with the known operational data and source 

term information provides support that a realistic dose 

can be determined
Joslyn SEC Petition 200

 What about employees not included in the SEC?

• NIOSH intends to use any internal monitoring data that 

may become available for an individual claim (and that 

can be interpreted using existing dose reconstruction 

processes or procedures). Therefore, dose 

reconstructions for individuals employed at the Joslyn 

site during the period from March 1, 1943 through July 

31, 1948, but who do not qualify for inclusion in the 

Special Exposure Cohort, may be performed using these 

data as appropriate.