National Institute for Occupational Safety and Health

Joslyn Manufacturing and Supply Co. Update

Alek Kranbuhl, M.S.

Health Physicist

TBD-6000 Work Group

February 14, 2024
Objectives

 Operations at Joslyn

 Review of open Findings

 NIOSH Assessment of Rolling Days

 NIOSH plan to address Findings
Operations at Joslyn
Joslyn Manufacturing and Supply Co. Overview:

 Located in Ft. Wayne, Indiana

 Performed a wide variety of metalworking operations for MED 

and AEC during covered period from March 1, 1943, to 

December 31, 1952

 Vital in the development of procedures for metalworking of 

natural uranium, including rolling and machining rods

 Joslyn produced large numbers of uranium rods for use in 

Hanford reactors from billets provided by MED
SC&A Review
TBD-6000 App. J Status:

 TBD-6000 Appendix J – Joslyn Approved Oct. 7, 2014 

 March 24, 2015, SC&A tasked with review of the document

 May 12, 2015, SC&A issued Review of “Site Profile for Atomic 

Weapons Employers That Worked Uranium Metals: Appendix J 

– Joslyn” (SCA-TR-SP2015-0050, Revision 0)

 Report details 7 findings and 2 observations
Findings 1-3:

 Finding 1: Underestimated Uranium Workdays

– The number of uranium working days at the site was 

underestimated due to only using confirmed rolling 

operations from records in the SRDB. The site’s contracts 

and billing with the U of C were not evaluated.

 Finding 2: Underestimated Inhaled Intakes

 Finding 3: Underestimated Photon and Electron Dose Rates 

from Contaminated Floor from Putzier Effect and Number of 

Rolling Days
Findings 4-7: 

 Finding 4: Underestimated Doses from External Exposure to 

Penetrating Radiation from Uranium

 Finding 5: Exposures Improperly Combined with Personal 

Dose Equivalents Hp(10)

 Finding 6: Underestimated Doses to Skin from Nonpenetrating 

Radiation from Uranium

 Finding 7: Underestimated External Exposure to Thorium

– Due to incorrect geometry in MCNP analysis
Summary of Observations:

 Observation 1: Insufficient information for review that is 

publicly available or cited

 Observation 2: Inconsistencies in General Assumptionsdifferences between TBD-6000 and Appendix – J
NIOSH Assessment of Rolling Days
Rolling Days Assessment:

 On July 19, 2023, NIOSH issued a white paper to address the 

number of operational days at the site

 Default assumptions had to be used in cases where 

information was lacking for:

– Average Billet and Rod Weight

– Average Billet-to-Rod Yield

– Production Rate for Rolling and Machining Operations
Average Billet and Rod Weight:

 Joslyn had several contracts with MED between March 1, 

1943, and December 31, 1952. 

 Some contracts detail number of billets delivered to the site 

and number of rods produced. [Greninger 1943; Foote 1944; 

DuPont 1945; Smith 1947]

 Combined information totals 636 billets and 1,028 rods with 

total weights of 157,436 lbs. (78.7 t) and 129,315 lbs. (64.7 t).

 Average weight of 248 lbs. per billet and 126 lbs. per rod.
Average Billet-to-Rod Yield:

 1949 Letter from the head of the Metallurgy and Control 

Division [Hauff 1949] provides a table of observed rolling and 

machining yields for billet-to-rod, billet-to-slug, rod-to-slug, 

solid scrap, and turning yields for Joslyn, Simonds, and Vulcan. 

 Average billet-to-rod yield across the three sites ranges from 

93.5% to 99.2%; billet-to-slug yield from 54.3% to 71.3%.

 This information was combined with the billet and rod weight 

data to produce an average billet-to-rod yield of 95% for 

Joslyn.
Production Rate for Rolling and Machining 

Operations:

 NIOSH determined production rates by evaluating several 

contracts which contained both billet and rod information and 

job length.

 Rolling rates varied from 5.3 t/day to 19.8 t/day.

 Machining rates were only available in two documents- 

[Simmons, 1943; Klevin, 1952] , which gave a rate of 15.8 rods 

per day and 12 rods per day, respectively.

 Claimant-favorable but realistic rates of 5.3 t/day and 12 rods 

(0.75t)/day for rolling and machining, respectively, were used.
Rolling Days Summary:

Year

Operational 

Daysa

Rolling

Days

Machining

Days

NonOperational

Days

Total

Workdays

1943 61 n/a n/a 191 252

1944 170 n/a n/a 130 300

1945 41 n/a n/a 259 300

1946 18 n/a n/a 282 300

1947 2 n/a n/a 298 300

01/01-07/31/1948 125 n/a n/a 49 174

08/01-12/31/1948 n/a 1 0 125 126

1949 n/a 2 21 277 300

1950 n/a 11 41 248 300

1951 n/a 1 1 273 275

1952 n/a 1 8 266 275

aRolling and machining days were combined during the SEC Period.
Year-By-Year Comparison Between SC&A and NIOSH:

Year

Operation 

Type

NIOSH 

Estimate

SC&A 

Estimate

Difference

(NIOSH-SC&A)

1943 Combined 61 32 +29

1944 Combined 170 201 -41

1945 Combined 41 63 -22

1946 Combined 18 86 -68

1947 Combined 2 6 -4

01/01-07/31/1948 Combined 125 110 +15

08/01-12/31/1948 Rolling 1 1 0

1949 Rolling 2 2 0

1949 Machining 21 5 +16

1950 Rolling 11 6 +5

1950 Machining 41 10 +31

1951 Rolling 1 0 +1

1951 Machining 1 2 -1

1952 Rolling 1 0 +1

1952 Machining 8 7 +1
Variability in 1944 & 1946

 1944: Difference of 41 days is primarily due to NIOSH’s 

assumption that Joslyn operated on a two shift, 16-hour day 

schedule, SC&A assumed a single, ten-hour shift.

 1946: Difference of 68 operational is due to SC&A’s 

assumption that it would take Joslyn 62 days to roll 12 tons of 

rods (0.1935t/day). NIOSH estimate uses a default rate of 5.3t 

per day.
Workdays Calculation for U of C Contract

NIOSH:

OOOOOOOOOOOOOOOOOOOOOO DDOODDDD =

$1111111111 (OOOOOOOOOO bbOOOOOOOObb OOaaOOaaOOOO)

$1111

hhOO (hhOOaaOOOODD bbOOOOOOOOOObb OOOOOOOO)

xx

11 wwOOOOwwbbOODD

1111 hhOOaaOODD

= 1166. 44 bbOODDDD

SC&A:

OOOOOOOOOOOOOOOOOOOOOO DDOODDDD =

$1111111111 (OOOOOOOOOO bbOOOOOOOObb OOaaOOaaOOOO)

$1111

hhOO (hhOOaaOOOODD bbOOOOOOOOOObb OOOOOOOO)

xx

11 wwOOOOwwbbOODD

1111 hhOOaaOODD

= 111111. 5511 bbOODDDD
Ensuring Claimant-Favorability

 This estimate likely exceeds the true number of operational 

days, from the information we evaluated because:

– Use of low-end production values

– Likely date overlap between documented operations and 

U of C contract

– Rolling and machining operations were considered to take 

place sequentially, when they were likely performed 

concurrently
Path Forward
Outstanding Issues

 With this estimate of operational days, intakes and external 

exposure can be assigned using the methods prescribed in 

TBD-6000 for Findings 1-4, and 6.

 Finding 5 is an error resulting from combining calculated 

exposures in milliroentgens with doses in millirem. This 

requires a conversion to organ dose.

 MCNP runs related to Finding 7 are being evaluated.
Sample External Dose Calculation:

Where:

DRRod, 1ft = dose rate from U rod @ 1 ft. (0.703 mrem/hr, TBD-6000 Table 6.1) 

hwd = hours in the workday

dop/non-op= number of days in an operational (nonoperational) period

DCFα/γ = conversion factor from alpha contamination to gamma dose rate 

(3.94E-10 [mR/hr]/[dpmα/m2], TBD-6000 Table 3.10)

 = contamination level (dpm/m2), derived from [A] (dpm/m3) x 1944 m 

(settling velocity x seconds/30d)
Where:

I = Intake (dpm)

dw= number of days the EE was employed in the year

[A]op = airborne concentration for a given operation, TBD-6000 Table 7.8

Rb = respiratory rate (1.2 m3/hr)

= contamination level (dpm/m2), derived from [A] (dpm/m3) x 1944 m

(settling velocity x seconds/30d)

RF = resuspension rate

Sample Intake Calculation:
Finding 3 & 6: Putzier Effect

 Proposed language change for TBD-6000 to describe Putzier 

Effect is incorporated in Rev. 1, Section 3.3.1

 Appendix J, Section J.5: “The beta dose from uranium metal 

was estimated by multiplying the photon dose rate by a factor 

of 10 in accordance with TBD-6000.”

 According to the BRS, issue was resolved with SCPR on 

1/6/2017
References

 DuPont [1945]. The metal fabrication program for the Clinton Engineer Works and 

the Hanford Engineer Works including the dummy slug program and the unbonded 

slug program – Project 1553. Wilmington, DE: E. I. du Pont de Nemours and 

Company. August. [SRDB Ref ID: 33190]

 Foote F [1944]. Preparation of slugs and inspection procedure alpha rolled slugs -

September 15,1944. Memorandum to A.B. Greninger. Metallurgical Laboratory, 

Chicago, IL: University of Chicago. November 27. [SRDB Ref ID: 101152]

 Greninger AB [1944]. Rolling and grinding of special steel. Letter to L. Frey, Joslyn 

Manufacturing and Supply Company. Metallurgical Laboratory, Chicago, IL: 

University of Chicago. April 28. [SRDB Ref ID: 196565]
Additional References

 Hauff TW [1949]. Rolled uranium - fabrication yields. Letter to F.C. Schlemmer, 

U.S. Atomic Energy Commission, Hanford Operations Office. Hanford Works, 

Richland, WA: General Electric Company. February 22. [SRDB Ref ID: 71035]

 SC&A [2015]. SC&A Draft: Review of “Site profiles for atomic weapons employers 

that worked uranium metals: appendix J-Joslyn.” Vienna, VA: S. Cohen and 

Associates. SCA-TR-SP2015-0050 Rev. 0, May 12. [SRDB Ref ID: 195945]

 Smith EA [1947]. Uranium rolling at Ft. Wayne, Ind. - August 5-6, 1947. 

Memorandum to T.W. Hauff. Hanford Engineer Works, Richland, WA: General 

Electric Company. HEW-7495, September 9. [SRDB Ref ID: 16511]
For more information, contact CDC

1-800-CDC-INFO (232-4636)

TTY: 1-888-232-6348 www.cdc.gov

The findings and conclusions in this report are those of the authors and do not necessarily represent the 

official position of the Centers for Disease Control and Prevention.