HHS Special Exposure Cohort Determination: 

Rocky Flats Plant, Golden, Colorado [SEC 00192]

U.S. Department of Health and Human Services 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 Certain Employees from 

Rocky Flats Plant 

Golden, Colorado
HHS Special Exposure Cohort Determination: 

Rocky Flats Plant, Golden, Colorado [SEC 00192]

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I. Determination 

I, Eric D. Hargan, Acting Secretary of Health and Human Services (Secretary) (HHS), 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. 

 November 8, 2017 [Signature on File]

Date Eric D. Hargan 

 

II. Employee Class Definition

All employees of the Department of Energy, its predecessor agencies, and their contractors 

and subcontractors who worked at the Rocky Flats Plant in Golden, Colorado, from January 

1, 1984, through December 31, 2005. 

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 the National Institute 

for Occupational Safety and Health (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 May 10, 2017, the Board, pursuant to 42 U.S.C. § 

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

radiation doses can be reconstructed with sufficient accuracy for certain employees at the 

Rocky Flats Plant (RFP) in accordance with provisions of EEOICPA and the SEC final rule. 
HHS Special Exposure Cohort Determination: 

Rocky Flats Plant, Golden, Colorado [SEC 00192]

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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 potential sources of internal radiation that NIOSH investigated during its evaluation 

of the proposed class included exposures to tritium, neptunium, thorium, uranium-233, 

and fission and activation products at the Critical Mass Laboratory (CML). The modes 

of exposure for the radionuclides of concern were ingestion and inhalation. 

• NIOSH concluded that tritium doses from the on-site, environmental release in 1973 can 

be reconstructed using the bioassay results collected after the release. Bioassay results 

from potentially exposed individuals can be used to reconstruct their tritium doses for the 

time period from January 1, 1974, through December 31, 2005. 

• Likewise, NIOSH concluded that doses from fission and activation products at the CML 

can be reconstructed using workplace air monitoring results coupled with information 

about the power level and duration of CML experiments. 

• The principal sources of external radiation doses for members of the proposed class were 

evaluated in the SEC-00030 RFP evaluation report. SEC-00030 concluded that all 

external doses except those for neutrons could be estimated with sufficient accuracy. 

Therefore, with respect to SEC-00192, NIOSH concluded that there is no need to again 

assess external exposures and dose reconstruction feasibility at RFP. 

• NIOSH also concluded that operations that posed significant potential for internal and 

external exposure to neptunium, thorium, and uranium-233 had ended by December 31, 

1983. Consequently, there is no need to reconstruct doses resulting from these 

radionuclides for the time period. 

• NIOSH has established that it has access to sufficient information to: (1) estimate the 

maximum radiation dose, for every type of cancer for which radiation doses are 

reconstructed, that could have been incurred in plausible circumstances by any member 

of the class; or (2) estimate radiation doses more precisely than an estimate of maximum 

dose. 

• The Board concurred with NIOSH's determination that dose reconstruction is feasible for 

the evaluated class of RFP workers during the period from January 1, 1984, through 

December 31, 2005, and therefore should not be added to the SEC.

Health Endangerment 
HHS Special Exposure Cohort Determination: 

Rocky Flats Plant, Golden, Colorado [SEC 00192]

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

radiation doses encountered by RFP 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 Department of Energy 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 will transmit a new report to Congress 

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