HHS Special Exposure Cohort Determination:

United Nuclear Corporation, Hematite, Missouri

HHS Determination Concerning a Petition to Add Members to the 

Special Exposure Cohort 

under the 

Energy Employees Occupational Illness Compensation Program Act of 

2000 

Determination Concerning a Petition for Employees from 

United Nuclear Corporation

Hematite, Missouri 
HHS Special Exposure Cohort Determination:

United Nuclear Corporation, Hematite, Missouri

I. Determination 

I, Kathleen Sebelius, Secretary of Health and Human Services (Secretary), have determined 

that the employees defined in Section II of this report do not meet the statutory criteria for 

addition to the Special Exposure Cohort (SEC), as authorized under the Energy Employees 

Occupational Illness Compensation Program Act of 2000 (EEOICPA), 42 U.S.C. § 7384q.

December 7, 2012 [Signature on File]

Date Kathleen Sebelius

II. Employee Class Definition

All site employees who worked in any area of the United Nuclear Corporation – 

Hematite, Missouri, site from January 1, 1958, through December 31, 1973, and the 

residual period January 1, 1974, through July 31, 2006.

III. Decision Criteria and Recommendations

Pursuant to 42 U.S.C. § 7384q, to designate a class for addition to the SEC, the Secretary 

must determine, upon recommendation of the Advisory Board on Radiation and Worker 

Health (Board), that

(1) It is not feasible to estimate with sufficient accuracy the radiation dose that the class 

received; and

(2) There is a reasonable likelihood that such radiation dose may have endangered the 

health of members of the class.

The SEC final rule states in 42 C.F.R. § 83.13(c)(1) that it is feasible in two situations to 

estimate the radiation dose that the class received with sufficient accuracy. First, the rule 

states that radiation doses may be estimated with sufficient accuracy if NIOSH has 

established that it has access to sufficient information to estimate the maximum radiation 

dose for every type of cancer for which radiation doses are reconstructed that could have 

been incurred under plausible circumstances by any member of the class. Alternatively, 

radiation doses may be estimated with sufficient accuracy if NIOSH has established that it 

has access to sufficient information to estimate the radiation doses of members of the class 

more precisely than a maximum dose estimate.

In a letter received by the Secretary on November 7, 2012, the Board, pursuant to 42 U.S.C. 

§ 7384q, agreed with the following NIOSH findings, effectively advising the Secretary that 

radiation dose can be reconstructed with sufficient accuracy for certain United Nuclear 

Corporation – Hematite, Missouri employees in accordance with provisions of EEOICPA and 

the SEC final rule.
HHS Special Exposure Cohort Determination:

United Nuclear Corporation, Hematite, Missouri

IV. Determination Findings

Feasibility of Estimating Radiation Doses with Sufficient Accuracy

The Secretary established the feasibility determination for the class of employees covered 

by this report based upon the findings summarized below.

• The principal sources of internal radiation dose for members of the class under 

evaluation were uranium metal and uranium oxides in the form of radioactive 

particulates. Thorium dioxide processing did not represent routine plant operations 

as it was a special project limited to a single time period in 1964.

• Bioassay and air sampling data are available in sufficient quantity and quality to 

adequately represent the potential internal exposures for the UNC-Hematite class 

under evaluation over the entire operational period. These data can also be used to 

support the evaluation of the UNC-Hematite internal dose over the site’s residual 

radioactivity period as described in Technical Basis Document for the United Nuclear 

Corporation Hematite, Missouri, (DCAS-TKBS-0008). NIOSH can bound the internal 

uranium dose associated with the weapons-related residual radioactivity that 

remained on site after the end of AEC-related operations.

• The available air sample data, including breathing zone and general air data, are 

available and can be used to supplement the bioassay data, or as the primary source 

of internal monitoring data for the period from 1961-1962. In addition, NIOSH has 

access to other radiological monitoring data and investigation reports that support 

bounding internal dose for UNC-Hematite from January 1, 1958, through December 

31, 1973, and the residual period January 1, 1974, through July 31, 2006.

• Although non-AEC-related radioactive materials work continued at UNC-Hematite 

after 1973, NIOSH is required to evaluate the potential internal exposures from the 

residual radioactivity that remained as a result of weapons-related work during the 

operational years at the site (1958-1973). The weapons-related work performed 

during the covered operational years involved uranium only. 

• NIOSH intends to use the personnel monitoring data and existing internal dose 

reconstruction processes and procedures set forth in the Technical Basis Document 

for the United Nuclear Corporation Hematite, Missouri, (DCAS-TKBS-0008), to 

reconstruct uranium dose for the class under evaluation. NIOSH may also use the 

available uranium air monitoring data, source term information, and process 

descriptions to supplement the reconstruction of the uranium dose and support 

bounding the associated dose. These resources support the ability to reconstruct 

uranium dose using methods that are more precise than a bounding dose estimate.

• The principal source of external radiation exposure for members of the class under 

evaluation was photon and beta (electron) radiation associated with AEC operational 

activities, including handling of radioactive materials in production or research 

activities; or radioactive waste-handling operations. Uranium metal and uranium 

compounds from natural and enriched uranium constituted the principal external 

radiation dose-producing material sources for members of the class.
HHS Special Exposure Cohort Determination:

United Nuclear Corporation, Hematite, Missouri

• NIOSH has obtained sufficient personal dosimetry records for individual workers 

exposed to beta and photon radiation during the AWE operations period. The 

available external dosimetry monitoring data are available in sufficient quantity and 

quality to adequately represent the potential for external exposures for the UNCHematite class under evaluation over the entire operational period. The dosimetry 

data are the primary data source that will be used to bound external dose for the 

UNC-Hematite class under evaluation. These data, applied as defined in the UNCHematite TBD, can also be used to support the evaluation of the UNC-Hematite 

external dose over the site’s residual radioactivity period. 

• NIOSH did not identify any neutron dosimetry data. However, based on its review of 

the available information, such as source material and the potential generation of 

neutrons from that material, NIOSH determined the neutron doses could be bound 

by using methods in ORAUT-OTIB-0024, Estimation of Neutron Dose Rates from 

Alpha-Neutron Reactions in Uranium and Thorium Compounds.

• Although no specific information regarding occupational medical dose has been 

identified for UNC-Hermatite, the dose associated with medical x-ray exams, if 

required as a condition of employment, can be bounded by using the assumptions in 

the complex-wide Technical Information Bulletin, Dose Reconstruction from 

Occupationally Related Diagnostic X-Ray Procedures (ORAUT-OTIB-0006). NIOSH 

believes this methodology supports its ability to bound the occupational medical xray doses for UNC-Hermatite. 

• Although non-AEC-related radioactive materials work continued at UNC-Hematite 

after 1973, NIOSH is required to evaluate the potential external exposures from the 

residual radioactivity that remained as a result of weapons-related work during the 

operational years (from January 1, 1958, through December 31, 1973). The 

Technical Basis Document for the United Nuclear Corporation Hematite, Missouri, 

(DCAS-TKBS-0008), provides a method to bound external doses associated with 

residual radioactivity exposures at UNC-Hematite.

• NIOSH has collected personnel and area monitoring data for the operational and 

post-AEC operations period. These data, coupled with the approaches defined in 

The Technical Basis Document for the United Nuclear Corporation Hematite, 

Missouri, (DCAS-TKBS-0008), support NIOSH’s ability to bound external dose for 

the residual radioactivity period. More precise external dose estimates can be 

evaluated by accounting for the depletion of the AEC-related source term/material 

over the UNC-Hematite residual period as presented and discussed in ORAUTOTIB-0070, Dose Reconstruction During Residual Radioactivity Periods at Atomic 

Weapons Employer Facilities.

• NIOSH determined that it has access to sufficient site-specific information to either 

(1) estimate the maximum internal and external radiation dose for every type of 

cancer for which radiation doses are reconstructed that could have been incurred 

under plausible circumstances by any member of the evaluated class; or (2) estimate 

the internal and external radiation doses to members of the evaluated class more 

precisely than a maximum dose estimate. 

• The Board concurred with NIOSH’s determination.
HHS Special Exposure Cohort Determination:

United Nuclear Corporation, Hematite, Missouri

Health Endangerment

Because the Secretary established that it is feasible to estimate with sufficient accuracy the 

radiation doses encountered by Weldon Spring employees as specified in this class, a 

determination of health endangerment is not required.

V. Effect of the Determination

Members of the class of employees covered by this determination and their survivors 

continue to be eligible to submit claims for compensation under EEOICPA. As required for 

cancer claims covering other DOE and Atomic Weapons Employer employees (or Atomic 

Weapons Employees) not included in the SEC, qualified cancer claims under Part B of 

EEOICPA for members of this class will be adjudicated by the Department of Labor, in part 

on the basis of radiation dose reconstructions which will be conducted by NIOSH.

VI. Administrative Review of Determination 

The determination provided in this report may be subject to an administrative review within 

HHS, pursuant to 42 C.F.R. § 83.18(a). On the basis of such a review, if the Secretary 

decides to designate the class of employees covered by this determination, in part or in 

whole, as an addition to the SEC, the Secretary would transmit a new report to Congress 

providing the designation and the criteria and findings on which the decision was based.