[Federal Register Volume 59, Number 89 (Tuesday, May 10, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-11227]
[[Page Unknown]]
[Federal Register: May 10, 1994]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-206]
Southern California Edison Company (San Onofre Nuclear Generating
Station, Unit 1); Exemption
I
Southern California Edison Company (SCE or the licensee) is the
holder of Facility Operating License No. DPR-13, which authorizes
possession and maintenance of the San Onofre Nuclear Generating
Station, Unit 1 (SONGS 1). The license provides, among other things,
that the licensee is subject to all rules, regulations, and orders of
the Commission now or hereafter in effect. The facility consists of a
permanently shutdown pressurized water reactor at the SCE site located
in San Diego County, California. SONGS 1 is co-located with San Onofre
Nuclear Generating Station, Units 2 and 3, which remain operational.
II
SONGS 1 was permanently shut down in November 1992, and defueling
of the reactor completed in March 1993. Upon licensee certification of
the defueling on March 9, 1993, Amendment No. 150 to Facility Operating
License No. DPR-13, modifying the license to preclude reactor
operation, became effective.
Title 10 of the Code of Federal Regulations, Sec. 140.11(a)(4) (10
CFR 140.11(a)(4)), requires each licensee to have and maintain primary
nuclear liability insurance in an amount equal to $200 million. In
addition, each licensee is required to maintain secondary financial
protection in the form of private liability insurance under an industry
retrospective plan. However, 10 CFR 140.8 allows that the Commission
may, upon application of any interested period or upon its own
initiative, grant such exemptions from the requirements of part 140 as
it determines are authorized by law and are otherwise in the public
interest.
By letter dated February 2, 1993, the licensee requested the
elimination of the current requirement for SONGS 1 to participate in
the industry retrospective rating plan for secondary level coverage as
required in 10 CFR 140.11(a)(4).
III
The Justification presented by the licensee for the request is that
the secondary financial protection requirements imposed by 10 CFR
140.11(a)(4) are applicable only to a reactor that is licensed to
operate and that is designed for the production of electrical energy
and has a rated capacity of 100,000 electrical kilowatts or more. The
licensee contends that the provisions of 10 CFR 140.11(a)(4) are no
longer applicable to SONGS 1, and there is no credible risk of an
accident at SONGS 1 with damages exceeding the $200 million primary
coverage which will remain in effect at the SCE site. SCE asserts that
because SONGS 1 will not benefit from secondary coverage it should not
be obligated to extend such coverage. Additionally, exclusion of SONGS
1 from the secondary financial program will remove the potential
liability (up to $75.5 million per event, but not more than $10 million
per year per event) that must be reported on SCE financial statements.
The NRC staff independently evaluated the legal and technical
issues associated with the application of the Price-Anderson Act to
permanently shut down reactors in SECY-93-127, ``Financial Protection
Required of Licensees of Large Nuclear Power Plants During
Decommissioning,'' May 10, 1993. In this evaluation, the staff
concluded that the Commission has discretionary authority to respond to
licensee requests for reduction in the level of primary financial
protection and withdrawal from participation in the industry
retrospective rating plan. Depending on the plant-specific
configuration and the time since permanent shutdown, the staff also
concluded that potential hazards may exist at permanently shut down
reactors for which financial protection is warranted. The staff also
concluded that accidents and hazards ensured against under Price-
Anderson go beyond design basis accidents and beyond those considered
``credible'' as that term is used in 10 CFR Part 100 and cases
interpreting the application of that regulation. The Commission issued
a staff requirements memorandum (SRM) addressing SECY-93-127 on July
13, 1993.
In the exercise of its discretionary authority, the Commission may,
as long as a potential hazard exists at a permanently shutdown reactor,
require the full amount of primary financial protection and full
participation in the industry retrospective rating plan. At such time
as the hazard is determined to no longer exist, the Commission may
reduce the amount of primary financial protection and permit the
licensee to withdraw from participation in the industry retrospective
rating plan.
Since the legislative history does not explicitly consider the
potential hazards that might exist after termination of operation, the
staff generically evaluated the offsite consequences associated with
normal and abnormal operations, design basis accidents, and beyond
design basis accidents for reactors that have been permanently defueled
and shut down. With regard to SONGS 1, the staff concluded that in view
of the time that has elapsed since plant shutdown, aside from the
handling, storage, and transportation of spent fuel and radioactive
materials, no reasonably conceivable potential accident exists that
could cause significant offsite damage.
A severe transportation accident could potentially result in local
contamination requiring cleanup and offsite liabilities resulting from
traffic disruption and loss of use. This type of accident would warrant
maintaining some level of liability insurance. The liabilities and
indemnification requirements associated with the transfer of spent fuel
from the licensee to the Department of Energy will be evaluated on a
case-by-case basis at a future time when spent fuel is shipped to a
repository.
Typically, the most significant accident sequence for a permanently
defueled and shutdown reactor involves the complete loss of water from
a light water reactor spent fuel pool. For a spent fuel pool that
contains fuel clad with Zircaloy, this beyond-design-basis accident
sequence could result in a Zircaloy fuel cladding fire that could
propagate through the spent fuel storage pool and result in significant
offsite consequences. Although such an accident is beyond the design
bases, it may be considered ``reasonably conceivable'' and could
warrant financial protection. Such an accident is possible during the
first year after reactor shutdown for a low density spent fuel storage
configuration and during the first two to three years after shutdown
for spent fuel stored in certain high density configurations. However,
the likelihood of occurrence of a fuel cladding fire at SONGS 1 is
negated because stainless steel, rather than Zircaloy, cladding is used
at SONGS 1. Zircaloy is a pyrophoric material which can undergo
spontaneous oxidation before it reaches its melting point. Zircaloy
fuel cladding can therefore oxidize by a self-sustaining reaction (at a
temperature of approximately 1650 deg.). Stainless steel, however,
cannot attain self-sustaining oxidation before it reaches its melting
point. This is due to the presence of chromium which forms an
impervious oxide film which prevents oxygen from reaching the metal
surface. Consequently, there is no temperature at which stainless steel
fuel cladding can support a self-sustaining oxidation reaction.
Therefore, the postulated cladding fire accident scenario is not
possible at SONGS 1. However, using the Zircaloy fuel cladding analysis
conservatively bounds the time at which fuel clad melting and fission
product release could occur at SONGS 1.
Once the requisite cooling period after reactor shutdown has
elapsed, fuel clad melting after a postulated loss of water is no
longer a concern since the fuel would air cool sufficiently. Possible
accident scenarios, after these cooling periods have elapsed, have
greatly reduced consequences, but could result in small releases or
precautionary evacuations which could result in offsite liability.
The staff considered liability coverage needs associated with
decommissioning activities and transportation of radioactive materials.
The staff recognizes that the potential hazards and consequences
associated with a reactor which has been permanently shut down with no
spent fuel are greatly reduced, that such a reactor does not contribute
a level of risk to the participants in the secondary pool proportionate
to that of an operating reactor and that relief from financial
protection requirements would then be warranted. The results of our
evaluation, as embodied in the July 13, 1993, SRM on SECY-93-127, allow
a reduction in the amount of financial protection required of licensees
of large nuclear plants that have been prematurely shut down. Although
the licensee presented an opinion regarding the application of the
Price-Anderson Act and 10 CFR Part 140 to permanently shut down
reactors, the staff did not concur with this licensee opinion.
Nonetheless, SCE meets the criterion established in SECY-93-127 for
relief from secondary financial protection requirements for low density
spent fuel storage. Specifically, more than 16 months have elapsed
since SONGS 1 was permanently shut down. This time period is
conservative for SONGS 1. The one-year cooling period prescribed in
SECY-93-127 was based on fuel with Zircaloy cladding; SONGS 1 fuel is
fabricated with stainless steel cladding which negates the likelihood
and consequences of the cladding fire sequence and shortens the time
after shutdown when fuel clad melting could occur upon loss of pool
water, as discussed above.
IV
The staff, based on its independent evaluation as embodied in the
July 13, 1993, SRM on SECY-93-127 ``Financial Protection Required of
Licensees of Large Nuclear Power Plants During Decommissioning,'' has
concluded that sufficient bases exist for our approval of relief from
the financial protection requirements for the San Onofre Nuclear
Generating Station, Unit 1. The staff has also concluded that granting
the proposed exemption does not increase the probability or
consequences of any accidents or reduce the margin of safety at this
facility.
V
Based on Sections III and IV above, the Commission has determined
that, pursuant to 10 CFR 140.8, this exemption is authorized by law and
is otherwise in the public interest. Therefore, the Commission grants
an exemption from the requirements of 10 CFR 140.11(a)(4) to the extent
that exemption from participation in the industry retrospective rating
plan (secondary level financial protection) is granted for the San
Onofre Nuclear Generating Station, Unit 1.
Pursuant to 10 CFR 51.32, the Commission has determined that the
granting of this exemption will not have a significant effect on the
quality of the human environment (59 FR 22872, dated May 3, 1994).
This exemption is effective upon issuance.
Dated at Rockville, Maryland this 4th day of May 1994.
For the Nuclear Regulatory Commission.
Brian K. Grimes,
Director, Division of Operating Reactor Support, Office of Nuclear
Reactor Regulation.
[FR Doc. 94-11227 Filed 5-9-94; 8:45 am]
BILLING CODE 7590-01-M
