October 19, 2000
The
Honorable Bill Richardson
Secretary
of Energy
U.S.
Department of Energy
1000
Independence Ave, SW
Washington,
DC 20585
Dear
Secretary Richardson:
We are writing to you concerning the
Surplus Plutonium Disposition Final Environmental Impact Statement (EIS) and
the associated Record of Decision (ROD) issued by the Department of Energy (DOE).
Since the ROD was issued on January 4 of this year,
significant new information has come to light regarding serious safety concerns
at the four nuclear reactors that DOE has selected to use mixed-oxide (MOX)
fuel derived from surplus weapons-grade plutonium. Consequently, as required by Council on Environmental Quality (CEQ)
and DOE National Environmental Policy Act (NEPA) implementing regulations (40
CFR 1502.9(c) and 10 CFR 1021.314, respectively), we request that DOE prepare
a new supplemental environmental impact statement that analyzes this "significant
new ... information relevant to environmental concerns and bearing on the proposed
action or its impacts."
Pending completion of the additional documents that
are required under NEPA, we also request that DOE suspend its contract with
Duke Cogema Stone & Webster (DCS), the consortium chosen to fabricate and
irradiate MOX fuel in the U.S. Until
the serious safety concerns that have emerged at the nuclear plants designated
for MOX use are fully resolved to the satisfaction of all stakeholders, the
ability of DCS to carry out the terms of the contract will remain in doubt.
The significant new information in
question is contained in a technical report that was issued by the Nuclear Regulatory
Commission (NRC) in April, Assessment
of the DCH [Direct Containment Heating] Issue for Plants with Ice Condenser
Containments (NUREG/CR-6427).
[1]
This report evaluates the vulnerability of
U.S. nuclear plants with ice condenser containments to early containment failure
in the event of a severe accident, where early containment failure is defined
as that occurring within a few hours of initiation of core melt, and before
effective evacuation of the public can take place. The study shows that "ice condenser plants
are substantially more sensitive to early containment failure than PWRs [pressurized-water
reactors] with large dry or subatmospheric containments" (Executive Summary,
p. xix).
As you know, the four reactors that Duke has designated
to irradiate MOX fuel, McGuire 1&2 and Catawba 1&2, have ice condenser
containments. NRC's new findings are
of particular concern in view of the potential use of MOX fuel in Duke's ice
condenser plants. The public health
consequences of a severe reactor accident with containment failure and core
dispersal will be significantly increased if MOX fuel is used, because of the
greater concentrations of plutonium and other actinides in MOX cores compared
to LEU cores.
[2]
This is exactly the type of accident to which
Catawba and McGuire are particularly susceptible. Therefore, it is incumbent upon DOE to thoroughly
analyze the risks to the public associated with the plutonium disposition program,
using the best available data. Anything less would be an abrogation of DOE's responsibility to
the public and a violation of its statutory requirements under NEPA.
NUREG/CR-6427 concludes that "ice condenser plants
are at least two orders of magnitude more vulnerable to early containment failure
than other U.S. PWRs." This is because ice condenser containment structures have, on average,
only one-half the ultimate failure pressure and containment volume of other
PWR containments, and cannot withstand credible hydrogen combustion events.
The risk of early containment failure is highest in
the event of an accident occurring during a station blackout, since in that
case the AC-powered hydrogen control system (glow plug igniters) would be disabled.
In particular, the NRC report finds, in the event of an accident with
station blackout, core melt and breach of the reactor vessel at high pressure,
that the probability of early containment failure is 100% for Catawba and 98%
for McGuire. Early containment failure is therefore a virtual certainty if this
accident scenario were to occur at one of Duke's ice condenser units. The total containment failure probability remains
high even when all accidents are considered, including those in which AC power
to the hydrogen control systems is maintained. Overall, the NRC report calculated that McGuire
has a probability of early containment failure given core damage of 13.9%, exceeding
NRC's screening criterion of 10%.
[3]
Based on these findings, NRC staff has recommended
that new regulatory requirements for ice condenser plants be considered.
[4]
NRC's new analysis of ice condenser
containment failure illustrates the weaknesses of the analyses carried out by
Duke for the McGuire and Catawba Individual
Plant Examinations (IPEs). In particular,
NRC's estimate of the McGuire early containment failure probability is seven
times greater than Duke's own estimate of 2%. However, DOE relied heavily on Duke's questionable
IPE accident probability data in its reactor accident analysis in the Surplus
Plutonium Disposition Final EIS. Therefore,
the findings contained in NUREG/CR-6427 clearly constitute "significant
new information relevant to environmental concerns," requiring DOE to perform
a new supplemental EIS under its NEPA implementing regulations.
We note that in the ROD for the Surplus
Plutonium Disposition EIS, DOE states that "NRC has not considered it necessary
to restrict operation of ... reactors in the United States that use ice condenser
containments." It also states that
safety issues associated with MOX use in ice condenser plants "will continue
to be evaluated," referring to comprehensive safety reviews to be performed
by NRC. NUREG/CR-6427 is an example of such a comprehensive safety review,
and its findings have a direct bearing on the environmental impact of DOE's
plutonium disposition program. It is
therefore DOE's obligation to analyze this new information in a supplemental
EIS and to suspend the MOX contract with DCS, which was let on the basis of
outdated safety information.
We look forward to receiving your prompt
reply to the requests stated above.
Sincerely,
___________________
Edwin S. Lyman, PhD
Scientific Director
_________________
Eldon V.C. Greenberg
Garvey, Schubert and Barer
Counsel
cc:
Laura Holgate, DOE/NNSA
[1] M. Pilch, K. Bergeron and J. Gregory, Assessment of the DCH Issue for Plants with Ice Condenser Containments, NUREG/CR-6427, SAND99-2553 (Albuquerque, NM: Sandia National Laboratories, April 2000).
[2] Edwin S. Lyman, "Public Health Consequences of Substituting Mixed-Oxide for Uranium Fuel in Light-Water Reactors," to appear in the journal Science and Global Security.
[3] It should be noted that this result applies to core damage caused by internal events only. External events, such as earthquakes, floods and tornadoes, are associated with a substantially higher probability of station blackout than internal events. Therefore, if external events are also considered, the fraction of core damage events culminating in early containment failure will be significantly higher than this value.
[4] U.S. Nuclear Regulatory Commission, Status Report on Study of Risk-Informed Changes to the Technical Requirements of 10 CFR Part 50 (Option 3) and Recommendations on Risk-Informed Changes to 10 CFR 50.44 (Combustible Gas Control), SECY-00-0198, September 14, 2000.