employment was specified 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) No evidence from the petitioners or from other resources was identified 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’s recommendation was that the health of the class may have been
endangered and that the class should be defined according to the 250-workday
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. §§ 7384(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. § 7384/(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.

HHS Special Exposure Cohort Designation:
Rocky Flats Plant


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 from

Rocky Flats Plant
Golden, Colorado

HHS Special Exposure Cohort Designation:
Rocky Flats Plant


I. Designation

I, Michael O. Leavitt, 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. § 7384.

AUG 0 6 2007
Sa ( SS
Date Michael O. Leavitt

Il. Employee Class Definition

Employees of the Department of Energy (DOE), its predecessor agencies, or
DOE contractors or subcontractors who were monitored or should have been
monitored for neutron exposures while working at the Rocky Flats Plant in
Golden, Colorado, for a number of work days aggregating at least 250 work
days from April 1, 1952, through December 31, 1958, 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 it is
established that there is 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 it is
established that there is 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 July 5, 2007.

HHS Special Exposure Cohort Designation:
Rocky Flats Plant


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.

(1) Many of the highest-exposed individuals at the Rocky Flats Plant were not
monitored for neutron exposure from April 1, 1952, through December 31,
1958.

(2) There were significant process changes during this time period which make it
infeasible to use data from later periods to estimate neutron doses during this
time period.

(3) Observed large variations between individual neutron dose rates and neutron-,
photon ratios suggest that using a correction factor at the building level is not
adequate for purposes of estimating individual doses.

(4) During the period 1952 through 1958, there were activities at the Rocky Flats
Plant that had the potential to expose some workers to significant neutron doses.
At the commencement of operations at the Rocky Flats Plant in 1952, the site
had limited neutron monitoring capabilities. Neutron exposures were monitored
using glass track plates supplied by the Los Alamos Scientific Laboratory, and
there were only about 20 plates per exchange cycle available. Neutron exposure
monitoring continually improved throughout the period 1952-1966, at which
point all highest exposed workers were monitored.

(5) Pursuant to 42 C.F.R. § 83.13(c)(1), it was determined that there is insufficient
information either 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, or to estimate the
radiation doses of members of the class more precisely than a maximum dose
estimate.

(6) There is sufficient information to reconstruct certain components of internal and
external dose for members of the class.

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), it was 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), a minimum duration of

HHS Special Exposure Cohort Designation:
Rocky Flats Plant