HHS Special Exposure Cohort Designation:

Medina Modification Center, San Antonio, Texas

 

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 

Medina Modification Center

San Antonio, Texas
HHS Special Exposure Cohort Designation:

Medina Modification Center, San Antonio, Texas

Page 2

I. Designation 

I, Kathleen Sebelius, Secretary of Health and Human Services, 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.

 August 23, 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 at the Medina Modification 

Center in San Antonio, Texas, from January 1, 1958, through December 31, 

1966, 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 August 1, 

2012. 
HHS Special Exposure Cohort Designation:

Medina Modification Center, San Antonio, Texas

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 the principal sources of internal radiation exposures for 

members of the Medina Modification Center proposed class included exposures 

to tritium, enriched uranium, depleted uranium, and plutonium during the 

assembly, inspection, and disassembly of weapons components, and enhanced 

radon in structures that were required to safely test nuclear weapons or 

components. 

• NIOSH found that tritium air sampling and urinalyses were performed. However, 

NIOSH has been unable to locate any recorded results of this monitoring. 

NIOSH has also identified a lack of information indicating urinalysis or other 

forms of internal monitoring were conducted to monitor for intakes of uranium or

plutonium. 

• NIOSH located very little documentation regarding the quantities of radiological 

materials shipped to the Medina Modification Center for processing and testing. It 

is clear from reports and worker communications that the site worked with 

uranium, tritium, and plutonium. However, without additional documentation, 

NIOSH is unable to ascertain the quantities of the source materials that may 

have been used or stored on site at any time during the period under evaluation. 

• In the absence of adequate internal dose monitoring criteria and adequate 

personnel monitoring data, NIOSH does not have sufficient general area air 

sampling, breathing zone air sampling, site survey, or source term information to 

allow it to bound potential internal exposures, or to demonstrate that workers 

were adequately monitored for potential exposures. Therefore, NIOSH finds that 

it is not feasible to estimate with sufficient accuracy the total internal dose for 

workers at the Medina Modification Center in San Antonio, Texas, during the 

period from January 1, 1958, through December 31, 1966. 

• NIOSH determined that the principal sources of external radiation exposures for 

members of the Medina Modification Center proposed class included exposures 

to enriched uranium, depleted uranium, and plutonium during the assembly, 

inspection, and disassembly of weapons components.

• NIOSH has access to individual external monitoring records for workers at the 

Medina Modification Center and summary exposure records from the years 1959 

through 1966. NIOSH intends to investigate the use of neutron-to-photon ratios 

based on data from similar operations to support reconstructing external neutron 

doses for members of the proposed class. 

• NIOSH has identified no information describing the medical x-ray examination 

requirements for the covered period at the site, but NIOSH intends to use its 

available methodology and its knowledge of the technology of that era to support 
HHS Special Exposure Cohort Designation:

Medina Modification Center, San Antonio, Texas

Page 4

reconstructing medical x-ray exposures for members of the proposed class. 

Based the available data, and the external and medical x-ray dose reconstruction 

methods available to NIOSH for the Medina Modification Center, NIOSH believes 

that is feasible to reconstruct external photon dose, including occupational 

medical doses, with sufficient accuracy for all Medina Modification Center

employees during the time period from January 1, 1958, through December 31, 

1966. 

• NIOSH finds that it has access to sufficient personnel and area monitoring data, 

and sufficient process and radiological source information, to support assessing 

external photon dose, including occupational medical dose, with sufficient 

accuracy, and that it may be feasible to reconstruct neutron doses. However, 

NIOSH lacks access to sufficient information and documentation that would allow 

it to estimate with sufficient accuracy the potential internal radiological exposures 

to which the proposed class may have been subjected at the Medina Modification 

Center employees during the time period from January 1, 1958, through 

December 31, 1966. 

• NIOSH has documented that it cannot complete the dose reconstructions related 

to this petition with sufficient accuracy for the employees who worked at the 

Medina Modification Center during the time period from January 1, 1958, through 

December 31, 1966. The basis of this finding demonstrates that NIOSH does not 

have access to sufficient information to estimate either the maximum radiation 

dose incurred by any member of the class or to estimate such radiation doses 

more precisely than a maximum dose estimate for that period.

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

doses for employees who worked at the Medina Modification Center during the 

time period from January 1, 1958, through December 31, 1966, NIOSH intends 

to reconstruct external exposures and use any internal monitoring data that may 

become available for an individual claim during this period (and that can be 

interpreted using existing NIOSH dose reconstruction processes or procedures) 

to support a partial dose reconstruction for individuals employed at the Medina 

Modification Center, during the time period from January 1, 1958, through 

December 31, 1966, but who do not qualify for inclusion in the SEC.

• 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.
HHS Special Exposure Cohort Designation:

Medina Modification Center, San Antonio, Texas

Page 5

 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 

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.