SEC Petition 116 - United Nuclear
 

Uranium Refining Atomic Weapons Employers Work Group
 

Henry A. Anderson, MD (Chair)
 

R. William Field, PhD
 

David Kotelchuck, PhD, MPH
 

Presented to:
 

The Advisory Board on Radiation and Worker Health
 

Denver, Colorado Meeting
 

September 18–20, 2012
 
 

 

 

 

 

United Nuclear - Summary
 

•	 The Uranium Refining AWE Work Group 

recommends that Petition 116 be denied 

•	 The Work Group review process underlying this 

recommendation will be described in the 

following slides 

•	 The presentation examines both the United 

Nuclear Site Profile and the SEC Petition 

Evaluation Report, since they are closely 

intertwined 

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United Nuclear – Site Description
 

•	 Located in Hematite, Missouri 

•	 Manufactured uranium metal and uranium 

compounds from natural and enriched 

uranium for use as nuclear fuel for U.S. Navy 

and commercial customers 

•	 Manufactured Th-U oxide pellets in 1964 

•	 Operations Period from 1958–1973 

•	 Residual Period from 1974–2009 

3 
 

 

 

United Nuclear – Chronology 

•	 March 2008 – NIOSH Issues Appendix D to 

TBD-6001 (Battelle 2008) – Site Profile for 

United Nuclear, Rev. 0 

•	 June 2008 – NIOSH receives SEC Petition 116
 

•	 November 2008 – NIOSH qualifies Petition 

116 for evaluation 

•	 August 2009 – NIOSH issues SEC Petition 

Evaluation Report (NIOSH 2009) 

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United Nuclear - Chronology (con’t)
 

•	 September 2009 – SC&A provides review of 

United Nuclear Site Profile only (SC&A 2009); 

Review makes 6 Findings. 

•	 February 2010 – NIOSH issues revision to 

Petition Evaluation Report (NIOSH 2010b) 

•	 April 2010 – NIOSH issues Rev. 1 to Appendix D 

(United Nuclear Site Profile) (NIOSH 2010a); 

Revised to include additional site-specific data 

•	 June 2010 – SC&A delivers review of Rev. 1 to 

Appendix D (SC&A 2010a) 

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United Nuclear - Chronology (con’t)
 

•	 September 2010 – SC&A delivers focused
 review NIOSH Petition Evaluation Report
 (SC&A 2010b) with 8 Findings
 

•	 March 2011 – NIOSH issues free-standing Site 

Profile replacing Appendix D of TBD-6001 

(DCAS 2011) 

•	 November 2011 – NIOSH issues white papers 

responding to SC&A review of PER (Davis 

2011, Clark 2011, Hughes 2011) 

•	 September 2012 – Work Group proposes to
 deny SEC Petition
 

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United Nuclear – Uranium Refining
 

AWE Work Group Activities
 

• July 7, 2010 (First meeting under TBD-6001 WG)
 

• November 4, 2010 

• May 16, 2011 

• August 16, 2011 (As Uranium Refining AWE WG)
 

• November 21, 2011 

• February 14, 2012 

• September 7, 2012 

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United Nuclear - Monitoring Data
 •	 Extensive bioassay data available at UNC 

•	 Bioassay coworker model developed for operators 

and supervisors/laborers for two periods: prior to 

June 1963 and after June 1963, when significant 

process improvements made at site 

•	 Bioassay data gap exists during 1961–1962, but air 

sampling data are available to validate bioassay
 model
 

•	 Coworker model intakes are more claimant-favorable 

than intakes based on air sampling for 1961–1962
 period (NIOSH 2011)
 

•	 NIOSH agreed to modify coworker model to use fixed
 95th percentile for gap period (1961–1962) and full
 distribution for other years (9/7/2012 WG Meeting)
 

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United Nuclear – Urinalysis Monitoring Data
 

Year No. of Employees No. of Samples 

1958 19 7 

1959 41 138 

1960 37 106 

1961 0 0 

1962 74 196 

1963 110 1730 

1964 45 1537 

1965 57 1238 

1966 87 1351 

1967 64 1320 

1968 116 op. /74 non-op 1845 

1969 131 1980 

1970 45 158 

Data for 1971–1973 available but not reliable. 

Source: NIOSH PER for SEC-116. 

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United Nuclear – Resolution of Site 

Profile Findings
 

•	 SC&A made 6 Findings based on its review of 

Appendix D of TBD-6001 (Battelle 2008) 

•	 Some of the Findings were inter-related with 

PER Findings 

• All Site Profile Findings have been resolved
 

in principle, but minor clean-up remains
 

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United Nuclear – Resolution of Site Profile
 

Finding #1
 

•	 SC&A Finding: Current guidance for assigning 

occupational medical dose is insufficiently 

prescriptive 

•	 Resolution: On November 4, 2010, the 

Uranium Refining AWE Work Group closed 

Finding #1 on the basis that there were no 

occupational medical exposures at the UNC 

site 

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United Nuclear – Resolution of Site Profile
 

Finding #2
 

•	 SC&A Finding: Default doses defined in 

Battelle-TBD-6001, Appendix D, Rev. 0 for 

external whole-body and skin doses are based 

exclusively on summary statements of a 1960 

AEC inspection report and may be 

inappropriate 

•	 Resolution: New dosimetry data covering the 

years 1958–1973 were subsequently 

incorporated in Battelle-TBD-6001, Appendix 

D, Rev. 1; the Work Group closed Finding #2 

on 11/4/2010 

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United Nuclear – Resolution of Site Profile
 

Finding #3
 

•	 SC&A Finding: Potential exposures to 

neutrons are not addressed in Battelle-TBD6001, Appendix D, Rev. 0 

•	 Resolution: In Section D.4.2 and Table D.4 of 

Battelle-TBD-6001, Appendix D, Rev. 1, NIOSH 

introduced modeled neutron doses for three 

job categories that employed claimantfavorable assumptions/model parameters that 

address Finding #3 

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United Nuclear – Resolution of Site Profile
 

Finding #4
 

•	 SC&A Finding14: The geometric mean of coworker 

inhalation intakes of uranium, as recommended by 

NIOSH in Table D.1 of Battelle-TBD-6001, Appendix D, 

Rev. 0 for all workers, may not correlate with 

empirical UNC urinalysis data for select years. 

•	 Resolution: (1) NIOSH has restricted the use of 

Table D.1 to UNC workers for whom bioassay data is 

inadequate; and (2) in the recent Work Group 

discussion (9/7/2012), NIOSH has agreed to use the 

95th percentile values of the coworker intakes 

defined in Table D.1 for 1961–1962 when no bioassay 

data are available. 

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United Nuclear – Resolution of Site Profile
 

Finding #5
 

•	 SC&A Finding: NIOSH provides insufficient 

information regarding the method used to derive 

inhalation intakes from residual contamination 

•	 Resolution (Conditional): In a Work Group session 

dated 11/4/2010, NIOSH agreed that there was a 

mathematical error in their calculation; NIOSH further 

agreed that this error will be addressed when the 

independent Site Profile (DCAS-TKBS-0008) is issued. 

Note, however, Table 4 of DCAS-TKBS-0008 contains 

the same erroneous values identified in Finding #5. (If 

this error in DCAS-TKBS-0008 is corrected, Finding #5 

will be considered resolved.) 

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United Nuclear – Resolution of Site Profile
 

Finding #6
 

•	 SC&A Finding: Section D.6 of Appendix D provides 

insufficient information that would allow the 

validation of default external dose estimates from 

residual contamination. 

•	 Resolution: In an attempt to validate NIOSH’s 

default external dose estimates from residual 

contamination, SC&A failed to include the dose 

contributions of short-lived daughters associated 

with U-234 and U-235. When this error was 

accounted for, SC&! validated NIOSH’s default 

external dose estimates and withdrew Finding #6. 

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United Nuclear – Resolution of PER
 

Findings 

•	 SC&A made 8 Findings based on its review 

of Rev. 1 of the Petition Evaluation Report 

•	 Some of the Findings were inter-related 

with Site Profile Findings 

•	 All PER Findings have been resolved 

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United Nuclear - PER Findings
 

•	 Finding A: There is a need for better documentation 

of the beta/gamma ratios used to reconstruct 

external doses 

•	 Finding B: How were the beta/gamma ratios derived 

and how will they be used in a claimant-favorable 

way for reconstructing external doses for 1961 

through 1965? 

• Resolution: Additional data were included in the Site 

Profile (DCAS 2011) (see also Site Profile Finding #2)
 

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United Nuclear – PER Findings (con’t)
 

•	 Finding C: Model used to reconstruct the neutron 

doses likely overestimates the doses significantly 

and needs to be based on assumptions that can 

be related to the actual operations at UNC 

•	 Resolution: Based on worker interviews, it was 

determined that the assumption of 2,000 hours 

per year was both bounding and plausible; the 

WG closed this issue at the 11/21/2011 meeting 

(ABRWH 2011, p. 156) 

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United Nuclear – PER Findings (con’t)
 

•	 Finding D: If dose estimates are to be based 

in some cases on air sample data alone, it is 

necessary to consider the possibility of 

inhalation of Type F material to avoid 

underestimates of doses to systemic tissues 

•	 Resolution: The coworker model is based on 

bioassay results – air sampling is not used in 

the model 

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United Nuclear – PER Findings (con’t)
 

•	 Finding E: For workers that might have been 

exposed to Type F uranium, the frequency of air 

sampling, bioassay sampling, and/or chest counting 

does not appear sufficient to provide adequate data 

for dose reconstruction. 

•	 Resolution: Issue discussed in detail at 11/4/2010 

WG meeting. NIOSH position that chronic exposures 

currently calculated as Type M or Type S are 

bounding for reasonable scenarios was accepted. 

Frequency of air sampling is not relevant, since air 

sampling not used for dose reconstruction. 

Sufficient bioassay sampling available to calculate 

bounding doses. 

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United Nuclear – PER Findings (con’t)
 

•	 Finding F: The use of air sampling data for 

dose reconstruction is not reliable 

•	 Resolution: The coworker model is based 

on bioassay results – air sampling is not 

used in the model 

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United Nuclear – PER Findings (con’t)
 

•	 Finding G: A discussion is needed describing why 

internal exposures can be reliably reconstructed, 

given the limited bioassay data available from 1961 

through 1962 and what appears to be the 

unreliability of air sampling data as a means to 

reconstruct internal doses. 

•	 Resolution: Air sampling results were used only to 

validate the assumption that exposures in 1961 and 

1962 were similar to the years before and after the 

data gap period (Hughes 2011): NIOSH will use the 

95th percentile of the bioassay coworker model for 

this period (09/07/2012 WG Meeting) 

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United Nuclear – PER Findings (con’t)
 

•	 Finding H: Considerably more information is needed 

before an assessment of the feasibility of 

reconstructing doses to thorium workers, even 

upper bound doses, can be made 

•	 NIOSH white paper (Davis 2011) provided evidence 

to WG that upper bound doses could be plausibly 

estimated. Issue closed at 11/21/2011 WG meeting 

(ABRWH 2011, p. 154). 

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United Nuclear – Naval Fuel 

Operations
 

•	 The WG initially had some concerns that classified 

activities at UNC might not have been adequately 

reflected in the NIOSH assessments 

•	 Therefore NIOSH interviewed an Item Plant Worker 

on February 28, 2012 (Interview 2012) 

•	 The worker also participated in the WG 

teleconference call on September 7, 2012 

•	 Discussions with worker provided considerable new
 

detail that confirmed NIOSH’s documented 

understanding of UNC operations 

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United Nuclear – Uranium Refining
 

AWE WG Recommendation
 

•	 Petition 116 covering “!ll site employees that worked 

in any area of the United Nuclear Corporation –

Hematite, MO, site from January 1, 1958 through 

December 31, 1973 and the residual radiation period 

January 1, 1974 through July 31, 2006” should be 

denied 

•	 Based on analysis of the available resources, there is 

no part of the class under evaluation for which 

radiation doses cannot be bounded under plausible 

circumstances 

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United Nuclear - References 

•	 Battelle 2008. Battelle-TBD-6001, Site Profiles for Atomic 

Weapons Employers the Refine Uranium and Thorium – Appendix D United Nuclear Corporation, March 14, 2008. 

•	 SC&A 2009. Review Of The NIOSH Site Profile For The United 

Nuclear Corporation, Missouri, Battelle-TBD-6001, Appendix 

D. September 2009. 

•	 NIOSH 2009. SEC Petition Evaluation Report for the United 

Nuclear Corporation, Petition SEC-00116. Rev. 0. August 17, 

2009. 

•	 SC&A 2010a. A Critical Review of Revision 1 of the NIOSH Site 

Profile for the United Nuclear Corporation, Missouri, 

Addendum to SCA-TR-SP2009-0040. June 24, 2010. 

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United Nuclear – References (con’t)
 

•	 SC&A 2010b. A Review of the SEC Petition Report For 

United Nuclear Corporation, Petition SEC-00116. September 2010.
 

•	 NIOSH 2010a. Rev. 1 to Appendix D. April 30, 2010. 

•	 NIOSH 2010b. SEC Petition Evaluation Report for the 

United Nuclear Corporation, Petition SEC-00116. Rev. 1. 

January 28, 2010. 

•	 DCAS 2011. Technical Basis Document for the United 

Nuclear Corporation , Hematite, Missouri. DCAS-TKBS- 0008. Effective Date 03/21/2011. (Replaces Appendix D) 

•	 Hughes 2011. United Nuclear Corporation Air 

Concentration Data for 1961 and 1962. Lara Hughes,
 

NIOSH/DCAS. November 2011.
 

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United Nuclear – References (con’t)
 

•	 Davis 2011. White Paper: Representativeness and 

Applicability of United Nuclear Corporation Air Sampling for 

Reconstructing Thorium Intakes. NIOSH. November 14, 2011. 

•	 Clark 2011. White Paper: SEC-00116 United Nuclear 

Corporation Petitioner Issues. Rev. 1. November 3, 2011. 

•	 ABRWH 2011. Transcript of the Uranium Refining AWE Work 

Group Meeting of November 21, 2011. Advisory Board on 

Radiation and Worker Health. 

http://www.cdc.gov/niosh/ocas/pdfs/abrwh/2011/wgtr11211 

1.pdf 

•	 Interview 2012. Interview with UNC Employee (34333), 

February 28, 2012. 

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