Carborundum Work Group 

SEC Petition 00223 

Recommendations 

ABRWH Meeting
 

Santa Fe, NM
 

November 30, 2016
 
 

 

Work Group Members
 

 Genevieve S. Roessler, Chair 

 Bradley P. Clawson 

 R. William Field 

 John W. Poston, Sr. 
Carborundum Company 

 Located in Niagara Falls, New York 

 Atomic Weapons Employer: June–Sept. 1943, 

1959–1967 

 Residual Radiation: 1943–1958, 1968–1992
 
 

EEOICPA Facility Listing 

 June–Sept. 1943: “In June of 1943, the 

Carborundum Company at its Globar Plant and 

Buffalo Avenue locations performed experimental 

grinding of uranium metal using a centerless 

grinder. Uranium slugs were received in June 

and return shipped in September 1943.” 
 

 

EEOICPA Facility Listing 

 1959 through 1967: Carborundum manufactured 

uranium and plutonium carbide pellets for an Atomic 

Energy Commission (AEC) research program. 

 Carborundum also performed work during the 1950s 

that is not covered under EEOICPA, including the 

fabrication of nuclear fuel elements for commercial 

purposes. 
 

 

 

 

Proposed and Evaluated SEC Class
 

 Petitioner-requested class definition: 

“All employees who worked in any area of the 

Carborundum Company facility on Buffalo Avenue, 

Niagara Falls, NY, from January 1, 1943 through 

December 31, 1976.” 

 Note: Because there are no identified dose reconstruction infeasibilities for 

the site, NIOSH limited its evaluation to the petitioner’s class period from 

1943 through 1976, rather than to 1992, the end of the residual period. 
Feasibility Summary
 

June–Sept. 1943 and 1959–1967 (operational periods) 

1943–1958 and 1968–1976 (residual periods) 

Source of Exposure Feasible Not Feasible 

Internal Yes —

External Yes —
SEC Petition 00223 

• Received November 19, 2014 

• Qualified for evaluation February 2, 2015 

• Revised Evaluation Report (ER) issued by NIOSH on June 3, 2015 

• SC&A review of NIOSH Evaluation Report issued January 27, 2016 

• NIOSH responded to SC&A Review: June 8 & 13, 2016 

• SC&A Issue Resolution Matrix: June 5, 2016 

• Work group meeting: August 18, 2016 
SC&A Findings on Carborundum SEC Petition 00223 

and the NIOSH SEC Petition Evaluation Report
 

1.	 NIOSH Failed to Prescribe a Methodology to Assess Doses to Skin of 

Hands and Forearms from X-Ray Diffraction (XRD) Apparatus 

(Closed) 

2.	 NIOSH Failed to Address Thorium as a P ossible Radiation Source 

(Site Profile Issue) 

3.	 NIOSH Failed to Account for the Use of 90Sr in Thickness Gauges at 

Carborundum (Closed) 

4.	 NIOSH Failed to Assign Doses from Medical X Rays During the First 

Operational Period (Closed) 

5.	 “Example DR” Failed to Assign Doses from Medical X Rays During 

the Second Operational Period (Closed) 

6.	 Inappropriate and Incorrect Use of FGR 12 (Closed) 

7.	 Dose Calculations in “Example DR” Are Not Reproducible (Site 

Profile Issue) 
 

 

 

 

 

 

 

 

 

 

Finding 1. NIOSH Failed to Prescribe a Methodology to Assess 

Doses to Skin of Hands and Forearms from X-Ray Diffraction 

(XRD) Apparatus 

SC&A Finding: The ER does not present a valid description of how NIOSH 

intends to assess doses to operators of XRD equipment. The methodology is 

based on exposures to XRD equipment at Sandia National Laboratory – 

Livermore. However, the same equipment and technical factor information is 

not available for Carborundum, so SC&A cannot determine how NIOSH 

intends to bound the XRD doses. 

Resolution: NIOSH acquired additional information and reassessed the dose 

to the XRD operators. It was concluded that the dose to the skin of hands and 

forearms will be assigned by using the exposure in the uranium work areas 

because it is bounding. SC&A agreed. The work group concluded that this 

finding is closed. 
 

 

 

 

 

 

Finding 2. NIOSH Failed to Address Thorium as a Possible 

Radiation Source 

SC&A Finding: The ER does not address exposures to thorium, despite a former 

worker’s having reported producing fuel pellets made from ThO2 and ThC in the mid1950s. The worker said the thorium was a powder and that spills were likely. 

Carborundum had two facilities for handling radioactive materials: one for uranium and 

thorium, another for plutonium. Since there is no record of a cleanup prior to the second 

operational period, workers exposed to intakes of uranium during the 1950s could also 

have been exposed to residual thorium contamination. Such exposures should be 

addressed in evaluating doses during the second operational period. 

Resolution: NIOSH and SC&A agreed that the thorium work was most likely not 

weapons related, so the operational period need not be extended to cover these 

activities. NIOSH observed that any residual airborne thorium activity would have been 

measured in the air samples of dust from the joint uranium/thorium facility. SC&A agreed, 

but noted that the dose conversion factors (DCFs) for 232Th are significantly higher than 

those for 234U. Consequently, the internal doses from uranium should reflect the 

possibility that some of the airborne activity was 232Th. NIOSH responded that the issue 

requires further study. However, NIOSH asserted, and SC&A agreed, that this is a site 

profile, not an SEC issue. The work group agreed that this is a site profile issue. 
 

 

 

 

 

 

 

 

 

 

 

 

Finding 3: NIOSH Failed to Account for the Use of 90Sr in Thickness 

Gauges at Carborundum 

SC&A Finding: The 1952 acquisition of five thickness gauges by Carborundum 

for quality control in the manufacture of sandpaper was reported in the New 

York Times. However, NIOSH was unaware of this information. AEC licensing 

documents related to the supplier of these gauges indicate that such devices 

can contain as much as 2 Ci of 90Sr. Strontium-90 and its short-lived (t1⁄2 = 64 h) 

90Y progeny, both almost pure ß emitters, would have been in secular 

equilibrium. This would have created a strong source of bremsstrahlung x rays, 

which could have contributed to doses from penetrating radiation and posed a 

radiation hazard to the skin of a worker. NIOSH needs to obtain more 

information on the use of such sources at Carborundum. 

Resolution: NIOSH did further research and determined that the Carborundum 

Division that used these gauges was located in Wheatfield, NY—a town near 

Niagara Falls. SC&A confirmed that information. Since this was not a covered 

facility, the issue is moot. The work group agreed that the finding is closed. 
 

 

 

 

 

 

 

 

 

 

Finding 4: NIOSH Failed to Assign Doses from Medical X Rays During the First Operational Period 

SC&A Finding: NIOSH did not to assign a medical x-ray dose during the first 

operational period on the basis of internal correspondence at DuPont, a 

wartime government contractor, that said that the grinding of uranium at 

Carborundum did not require medical supervision. This is irrelevant to routine 

physical examinations, which might have included medical x rays. According to 

a DCAS guidance document, doses from screening x rays are to be assigned if 

they were part of a required annual physical examination. The ER is 

inconsistent in prescribing the assignment of medical x rays during the second 

operational period but not the first. Furthermore, one of the petitioners stated 

that another worker had physical exams at the site, raising the possibility that 

medical x rays were performed on site. 

Resolution: NIOSH agreed that dose from a single x-ray examination should 

be assigned in dose reconstructions for claimants with employment in 1943. 

SC&A agreed that the issue was therefore resolved. The work group agreed 

that the finding is closed. 
 

 

 

 

 

 

 

 

 

Finding 5: “Example DR” Failed to Assign Doses from Medical X Rays 

During the Second Operational Period 

SC&A Finding: According to the ER, “NIOSH will assume that preemployment, annual, and termination PA radiographic chest x-ray screenings 

were performed for workers during the second operational period.” However, 

“Example DR,” a document in support of the ER that is posted on the DCAS 

restricted website, explicitly states that no medical x-ray doses were assessed 

to the hypothetical worker who was employed during both operational periods. 

This inconsistency needs to be resolved. 

Resolution: NIOSH agreed to include medical x rays in dose reconstructions 

(DRs) for this period. SC&A concurred with this resolution. The work group 

agreed that the finding is closed. 
 

 

 

 

 

 

 

 

 

Finding 6: Inappropriate and Incorrect Use of Federal Guidance 

Report No. 12 

SC&A Finding: The ER used several scenarios described in Battelle-TBD-6000 to 

estimate internal and external doses from intakes of uranium dust and from exposure to 

uranium metal. However, NIOSH used Federal Guidance Report No. 12 (FGR 12) to 

calculate doses from submersion in a cloud of radioactive dust and from exposure to 

contaminated surfaces instead of using the values listed in TBD-6000. The photon dose 

coefficient for a surface contaminated with uranium used by NIOSH is only ~29% of the 

value in TBD-6000. This procedure is inconsistent with the use of TBD-6000 for other 

pathways and for DRs at other work sites. Furthermore, it is not scientifically correct, 

since NIOSH does not have a prescribed method of deriving organ dose equivalents from 

effective dose equivalents, the dosimetric quantities listed in FGR 12. However, in the 

case of Carborundum, the external doses from penetrating radiation are a few mrem/y, 

so these discrepancies are not highly significant. Doses to the skin from nonpenetrating 

radiation from uranium-contaminated surfaces are on the order of a few hundred mrem 

during the first few years of the first residual period. Consequently, the value derived from 

FGR 12 skin doses, which is only ~72.5% of the value in TBD-6000, could affect the 

outcome of a DR. 

Resolution: NIOSH agreed to use TBD-6000 values for DRs. The work group agreed 

that the finding is closed. 
 

 

 

 

 

 

 

 

 

 

Finding 7: Dose Calculations in “Example DR” Are Not Reproducible 

SC&A Finding: SC&A audited doses to four organs presented in “Example DR.” 

Differences were found significant in both internal and external doses. The 

ABRWH procedures for reviews of NIOSH SEC petition ERs recommend that 

NIOSH include in its evaluation a demonstration that it is feasible to reconstruct 

individual doses for the cohort, including sample DRs. Until the results of sample 

DRs can be verified, it cannot be concluded that NIOSH can reconstruct doses to 

Carborundum workers. 

Resolution: NIOSH responded that the doses in the example DR were not 

precise best estimates. The example DR employed some efficiency measures, 

some of which resulted in higher doses. The example DR used incorrect DCFs for 

external exposure and used solubility Type F for intakes from the 1943 uranium 

metal grinding work, while only Types M and S are applicable. NIOSH stated that it 

can provide an updated example dose calculation showing details of the annual 

dose calculations, but noted that SC&A also had comments on the interpretation of 

data to estimate both internal and external doses. NIOSH believes that those 

comments should be resolved before it provides an updated example calculation. 

Meeting participants agreed that these are site profile and not SEC issues. The 

work group agreed that this is a site profile issue. 
 

 

Use of Surrogate Data from TBD-6000 

 The DCAS assessment of doses relies on surrogate data in 

TBD-6000 to estimate external and internal doses for the 1943 

experimental work with uranium metal. 

 It also relies on surrogate data for the reconstruction of 

external doses from uranium work in 1959 through 1967. 

 External doses from the mixed uranium/plutonium compounds 

do not rely on surrogate data, nor do estimates of intakes for 

1959 through 1967. 
 

 

 

 

 

 

SC&A Findings on Use of Surrogate Data from TBD-6000 

 Intakes of Uranium Aerosols: First Operational Period 

 Airborne activity concentrations: assumed arithmetic mean 

BZ = 20,192 vs. 13,000 dpm/m3 (Harris and Kingsley 1959)
 

 Satisfy ABRWH criteria? 

 Hierarchy of data ✔

 No site-specific airborne dust measurements for uranium machining 

operations at Carborundum 

 Exclusivity constraint ✔

 Site and process similarities ✔

 Centerless grinding at both sites 

 No ventilation at either site 

 Temporal considerations: different time frames, but 

 Centerless grinding at both sites ✔

 No ventilation at either site ✔

 Plausibility ✔

 Values comparable within variability and uncertainty 

 Conclusion: surrogate data on uranium intakes satisfy all five ABRWH 

criteria 
 

 

 

 

 

 

 

 External Exposure to Uranium Metal 

 Actual source terms 

 1st operational period: 13.6 kg of natural uranium metal slugs on site 

 2nd operational period: 

 Carborundum requested 4.5 kg of uranium shot 

 Produced batches of 30 g to 2.7 kg 

 NIOSH used MCNP model of 477-kg uranium ingot 

 Satisfy ABRWH criteria? 

 Hierarchy of data ✔

 Exclusivity constraint: other source terms available X 

 Site and process similarities: major differences in source terms X 

 Temporal considerations: computer model not time dependent N/A 

 Plausibility: major differences in actual and modeled source terms X 

 Suggested resolution of discrepancies 

 1st period: Use modeled dose rate from 7 slugs (total mass = 14 kg) 

 2nd period: Use modeled dose rate from uranium plate (mass = 3.1 kg) 

 Not an SEC issue: other source terms available in TBD-6000 
 

 

Work Group Conclusions 

 The work group concluded that, with appropriate 

adjustments, NIOSH can reconstruct doses for 

the proposed SEC class. 

 The work group moves that SEC Petition 00223 

be denied. 
Questions?