HHS Special Exposure Cohort Designation:

Oak Ridge National Laboratory (X-10), Oak Ridge, Tennessee

 

HHS Designation of Additional Members of the 

Special Exposure Cohort 

under the 

Energy Employees Occupational Illness Compensation Program Act 

of 2000 

Designating a Class of Employees 

Oak Ridge National Laboratory (X-10)

Oak Ridge, Tennessee
HHS Special Exposure Cohort Designation:

Oak Ridge National Laboratory (X-10),Oak Ridge, Tennessee

Page 2

I. Designation 

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

designate the class of employees defined in Section II of this report 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 employees of the Department of Energy, its predecessor agencies, and 

their contractors and subcontractors who worked in any area at the Oak 

Ridge National Laboratory (X-10) in Oak Ridge, Tennessee, from June 17, 

1943, through July 31, 1955, 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 in the Special Exposure Cohort.

III. Designation Criteria and Recommendations

Pursuant to 42 U.S.C. § 7384q, for the class defined in Section II of this report, the 

Secretary has determined, and the Advisory Board on Radiation and Worker Health 

(Board) has recommended, 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.

The Board, pursuant to 42 U.S.C. § 7384q, advised the Secretary to designate the 

class as an addition to the SEC in a letter received by the Secretary on November 7, 

2012. 
HHS Special Exposure Cohort Designation:

Oak Ridge National Laboratory (X-10),Oak Ridge, Tennessee

Page 3

IV. Designation 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.

• NIOSH determined that principal sources of internal radiation for members of the 

Oak Ridge National Laboratory (X-10) proposed class included plutonium, 

uranium, thorium, mixed fission products, and various cyclotron-related 

radionuclides.

• Based on NIOSH’s evaluation of available data, NIOSH concluded that it is not

feasible for NIOSH to reconstruct with sufficient accuracy the internal doses at 

the Oak Ridge National Laboratory (X-10) from: uranium exposures during the 

period June 17, 1943, through December 31, 1948; thorium exposures during the 

period from January 1, 1948, through July 31, 1955; and mixed fission product 

exposures during the period from November 4, 1943, through December 31, 

1949. Combining these periods of infeasibility yields a collective time period for 

dose reconstruction infeasibilities of June 17, 1943, through July 31, 1955.

• NIOSH has access to Oak Ridge National Laboratory (X-10) urine bioassay and 

air sampling data and believes that for various periods of time between June 17, 

1943, and July 31, 1955, it may be feasible to reconstruct doses for some of the 

other principal sources of internal radiation dose. However, during the period 

between June 17, 1943, and July 31, 1955 internal doses cannot be 

reconstructed for all principal sources of internal radiation dose. NIOSH will 

continue to evaluate additional urine bioassay data if it becomes available.

• NIOSH has determined that cyclotron-related radionuclides produced at the 

nearby Y-12 Facility were processed at the Oak Ridge National Laboratory (X10) during the period under evaluation. NIOSH has reserved the evaluation of 

Oak Ridge National Laboratory (X-10) exposures to various radionuclides 

produced as a result of Y-12 cyclotron operations to allow cyclotron-related 

operations and exposures at the two sites to be collectively evaluated.

• NIOSH determined that the principal source of external radiation doses for 

members of the Oak Ridge National Laboratory (X-10) proposed class was a 

combination of direct exposure from various fission products, production nuclides 

from the reactors. Photon and beta exposure at the Oak Ridge National 

Laboratory (X-10) resulted from the mixed fission and activation products from 

the reactors and from isotopes produced at Y-12. Direct photon exposure 

resulted from work in the proximity of the test and the research nuclear reactors.

• NIOSH has sufficient data that includes name of the employee, badge number, 

sample date, year, “Gamma_Exposure,” and “Beta_Exposure” (the field labeled 

“Gamma_Exposure” includes all site-assigned neutron exposure results). NIOSH 

has evaluated the available information and believes that external dose 

reconstruction is feasible.
HHS Special Exposure Cohort Designation:

Oak Ridge National Laboratory (X-10),Oak Ridge, Tennessee

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• Prior to October 3, 1947, occupational medical X-rays were performed at Oak 

Ridge Hospital (an EEOICPA-covered site located on what was then the Clinton 

Engineering Works site). Starting October 3, 1947, occupational medical X-rays 

were performed on the Oak Ridge National Laboratory (X-10) site. NIOSH has 

determined that adequate reconstruction of medical dose is feasible by using 

claimant-favorable assumptions and the technical information bulletin Dose 

Reconstruction from Occupational Medical X-Ray Procedures (ORAUT-OTIB0006). ). Therefore, NIOSH concluded that reconstruction of external doses, 

including occupational medical doses, is likely feasible for the period from June 

17, 1943, and July 31, 1955. 

• NIOSH determined that it lacks sufficient information, which includes specific 

biological monitoring data, air monitoring information, process and radiological 

source information, and surrogate data from similar operations at other sites that 

would allow it to estimate the total internal dose from exposures to all the 

principal sources of internal radiation for all workers who worked at the Oak 

Ridge National Laboratory (X-10) during the period from June 17, 1943, through 

July 31, 1955. Based on the available information, NIOSH believes external dose 

reconstruction is feasible for the evaluated time period.

• Although NIOSH found that it is not possible to completely reconstruct radiation 

doses for the proposed class, NIOSH intends to use any internal and external 

monitoring data that may become available for an individual claim (and that can 

be interpreted using existing NIOSH dose reconstruction processes or 

procedures). Therefore, dose reconstructions for individuals employed at Oak 

Ridge National Laboratory (X-10) facility during the period from June 17, 1943, 

through July 31, 1955, but who do not qualify for inclusion in the SEC, may be 

performed using these data as appropriate.

• Pursuant to 42 C.F.R. § 83.13(c)(1), NIOSH determined that there is insufficient 

information to either: (1) 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; or (2) 

estimate the radiation doses of members of the class more precisely than a 

maximum dose estimate.

• The Board concurred with the NIOSH evaluation and recommended the 

proposed class for addition to the SEC.

 Health Endangerment

The Secretary established the health endangerment determination for the class of 

employees covered by this report based upon the findings summarized below.

(1) Pursuant to 42 C.F.R. § 83.13(c)(3), NIOSH established that there is a 

reasonable likelihood that such radiation doses may have endangered the 

health of members of the class. Pursuant to 42 C.F.R. § 83.13(c)(3)(ii), 

NIOSH specified a minimum duration of employment to satisfy this health 

endangerment criterion as “having been employed for a number of work days 
HHS Special Exposure Cohort Designation:

Oak Ridge National Laboratory (X-10),Oak Ridge, Tennessee

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aggregating at least 250 work days within the parameters established for this 

class or in combination with work days within the parameters (excluding 

aggregate work day requirements) established for one or more other classes 

of employees in the Cohort.”

(2) NIOSH did not identify any evidence from the petitioners or from other 

resources that would establish that the class was exposed to radiation during 

a discrete incident likely to have involved exceptionally high-level exposures, 

such as a nuclear criticality incident, as defined under 42 C.F.R. § 

83.13(c)(3)(i). 

(3) The Board concurred with NIOSH’s finding that the health of the class may 

have been endangered and defined the class according to the 250-work day 

requirement specified under 42 C.F.R. § 83.13(c)(3)(ii). 

V. Effect and Effective Date of Designation

The Secretary submits this report on the designation of one additional class to the 

SEC for review by Congress, pursuant to 42 U.S.C. §§ 7384l(14)(C)(ii) and 

7384q(c)(2)(A), as amended by the Ronald W. Reagan National Defense 

Authorization Act for Fiscal Year 2005, Pub. L. No. 108-375 (codified as amended in 

scattered sections of 42 U.S.C.). Pursuant to 42 U.S.C. § 7384l(14)(C)(ii), as 

amended by the Ronald W. Reagan National Defense Authorization Act for Fiscal 

Year 2005, Pub. L. No. 108-375 (codified as amended in scattered sections of 42 

U.S.C.), the designation in this report will become effective 30 days after the date of 

this report’s submission to Congress “unless Congress otherwise provides.”

VI. Administrative Review of Designation

The health endangerment determination of the designation 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 expand the class 

of employees covered by this designation, the Secretary would transmit a 

supplementary report to Congress providing the expanded employee class definition 

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