[Federal Register Volume 68, Number 193 (Monday, October 6, 2003)]
[Notices]
[Pages 57714-57715]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-25243]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-302]
Florida Power Corporation, Crystal River Unit 3 Nuclear
Generating Plant; Exemption
1.0 Background
Florida Power Corporation (the licensee) is the holder of Facility
Operating License No. DPR-72, which authorizes operation of the Crystal
River Unit 3 Nuclear Generating Plant (CR-3). The license provides,
among other things, that the facility is subject to all rules,
regulations, and orders of the U.S. Nuclear Regulatory Commission (the
Commission) now or hereafter in effect.
The facility consists of one pressurized-water reactor located in
Citrus County, Florida.
2.0 Request/Action
Section 50.44 of Title 10 of the Code of Federal Regulations (10
CFR 50.44), ``Standards for combustible gas control system in light-
water-cooled power reactors,'' requires, among other items, that
``[e]ach boiling or pressurized light-water nuclear power reactor
fueled with oxide pellets within cylindrical zircaloy or ZIRLO cladding
must, as provided in paragraphs (b) through (d) of [that] section,
include means for control of hydrogen gas that may be generated,
following a postulated loss-of-coolant accident (LOCA) by: (1) [m]etal-
water reaction involving the fuel cladding and the reactor coolant, (2)
[r]adiolytic decomposition of the reactor coolant, and (3) [c]orrosion
of metals.''
Section 50.46 of 10 CFR Part 50, ``Acceptance criteria for
emergency core cooling systems for light-water nuclear power
reactors,'' requires, among other items, that ``[e]ach boiling or
pressurized light-water nuclear power reactor fueled with uranium oxide
pellets within cylindrical zircaloy or ZIRLO cladding must be provided
with an emergency core cooling system (ECCS) that must be designed so
that its calculated cooling performance following postulated [LOCAs]
conforms to the criteria set forth in paragraph (b) of [that] section.
ECCS cooling performance must be calculated in accordance with an
acceptable evaluation model and must be calculated for a number of
postulated [LOCAs] of different sizes, locations, and other properties
sufficient to provide assurance that the most severe postulated LOCAs
are calculated.''
Appendix K to 10 CFR Part 50, ``ECCS Evaluation Models,'' requires,
among other items, that the rate of energy release, hydrogen
generation, and cladding oxidation from the metal/water reaction shall
be calculated using the Baker-Just equation.
Finally, 10 CFR 50.44, 10 CFR 50.46, and 10 CFR part 50, appendix K
make no provisions for use of fuel rods clad in a material other than
zircaloy or ZIRLO. The licensee has requested the use of Framatome
Cogema Fuels (FCF) ``M5'' advanced alloy for fuel rod cladding for the
CR-3 operating Cycle 14. The M5 alloy is a proprietary zirconium-based
alloy comprised of primarily zirconium ([sim]99 percent) and niobium
([sim]1 percent). The elimination of tin has resulted in superior
corrosion resistance and reduced irradiation-induced growth relative to
both standard zircaloy (1.7% tin) and low-tin zircaloy (1.2% tin). The
addition of niobium increases ductility, which is desirable to avoid
brittle failures. Since the chemical composition of the M5 alloy
differs from the specifications for zircaloy or ZIRLO, a plant-specific
exemption is required to allow the use of the M5 alloy as a cladding
material at CR-3.
Section 50.12 of 10 CFR Part 50, ``Specific exemptions,'' states,
among other items, that the Commission may, upon application by any
interested person or upon its own initiative, grant exemptions from the
requirements of the regulations of this part, which are authorized by
law, will not present an
[[Page 57715]]
undue risk to the public health and safety, and are consistent with the
common defense and security. The Commission will not consider granting
an exemption unless special circumstances are present. In accordance
with 10 CFR 50.12(a)(2)(ii), special circumstances are present whenever
application of the regulation in the particular circumstances would not
serve the underlying purpose of the rule or is not necessary to achieve
the underlying purpose of the rule.
3.0 Discussion
The underlying purpose of 10 CFR 50.46 is to ensure that facilities
have adequate acceptance criteria for ECCS. On February 4, 2000, the
NRC staff approved Topical Report BAW-10227P, ``Evaluation of Advanced
Cladding and Structural Material (M5) in PWR Reactor Fuel,'' in which
Framatome Cogema Fuels (FCF) demonstrated that the effectiveness of the
ECCS will not be affected by a change from zircaloy fuel rod cladding
to M5 fuel rod cladding. The analysis described in the topical report
also demonstrates that the ECCS acceptance criteria applied to reactors
fueled with zircaloy clad fuel are also applicable to reactors fueled
with M5 fuel rod cladding.
The underlying purposes of 10 CFR 50.44 and 10 CFR part 50,
appendix K, paragraph I.A.5, are to ensure that cladding oxidation and
hydrogen generation are appropriately limited during a LOCA and
conservatively accounted for in the ECCS evaluation model.
Specifically, Appendix K requires that the Baker-Just equation be used
in the ECCS evaluation model to determine the rate of energy release,
cladding oxidation, and hydrogen generation. In their topical report
BAW-10227P, FCF demonstrated that the Baker-Just model is conservative
in all post-LOCA scenarios with respect to the use of the M5 advanced
alloy as a fuel rod cladding material, and that the amount of hydrogen
generated in an M5-clad core during a LOCA will remain within the CR-3
design basis.
The NRC staff has reviewed the licensee's advanced cladding and
structural material, M5, for pressurized-water reactor fuel mechanical
designs as described in BAW-10227P. In a safety evaluation dated
February 4, 2000, for topical report BAW-10227P, the NRC staff
concluded that, to the extent and limitations specified in the staff's
evaluation, the M5 properties and mechanical design methodology are
acceptable for referencing in fuel reload licensing applications.
Therefore, since the underlying purposes of 10 CFR 50.44, 10 CFR 50.46,
and 10 CFR part 50, appendix K, paragraph I.A.5 are achieved through
the use of the M5 advanced alloy as a fuel rod cladding material, the
special circumstances required by 10 CFR 50.12(a)(2)(ii) for the
granting of exemptions to 10 CFR 50.44 and 10 CFR part 50, appendix K,
paragraph I.A.5 exist.
4.0 Conclusion
The Commission has determined that, pursuant to 10 CFR 50.12, this
exemption is authorized by law, will not endanger life or property or
the common defense and security, and is otherwise in the public
interest. Therefore, the Commission hereby grants the licensee an
exemption from the requirements of 10 CFR 50.44, 10 CFR 50.46, and 10
CFR part 50, appendix K.
Pursuant to 10 CFR 51.32, the Commission has determined that the
granting of this exemption will have no significant impact on the
environment (68 FR 55662).
This exemption is effective upon issuance.
Dated at Rockville, Maryland, this 26th day of September 2003.
For the Nuclear Regulatory Commission.
Ledyard B. Marsh,
Director, Division of Licensing Project Management, Office of Nuclear
Reactor Regulation.
[FR Doc. 03-25243 Filed 10-3-03; 8:45 am]
BILLING CODE 7590-01-P