[Federal Register Volume 64, Number 88 (Friday, May 7, 1999)]
[Notices]
[Pages 24683-24684]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-11515]
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NUCLEAR REGULATORY COMMISSION
[Docket Nos. 50-275 and 50-323]
Pacific Gas and Electric Company (Diablo Canyon Nuclear Power
Plant, Units 1 and 2); Exemption
I
Pacific Gas and Electric Company, et al. (the licensee) is the
holder of Facility Operating License Nos. DPR-80 and DPR-82, which
authorize operation of the Diablo Canyon Nuclear Power Plant (DCNPP),
Units 1 and 2. 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 two pressurized-water reactors at the
licensee's site located in San Luis Obispo County, California.
II
Section 50.60 of Title 10 of the Code of Federal Regulations (10
CFR), ``Acceptance criteria for fracture prevention measures for
lightwater nuclear power reactors for normal operation,'' paragraph (a)
states, in part, that ``all light-water nuclear power reactors, * * *
must meet the fracture toughness and material surveillance program
requirements for the reactor coolant pressure boundary set forth in
appendices G and H to this part.'' Pressurized water reactor licensees
have installed cold overpressure mitigation systems/low temperature
overpressure protection systems (LTOP) in order to protect the reactor
coolant pressure boundary from being operated outside of the boundaries
established by the pressure temperature (P/T) limit curves and to
provide pressure relief of the reactor coolant pressure boundaries
during low temperature overpressurization events.
III
Section 50.12(a) of 10 CFR, ``Specific exemption,'' states 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: (1) Authorized by law,
will not present an undue risk to the public health
[[Page 24684]]
and safety, and are consistent with the common defense and security.
(2) The Commission will not consider granting an exemption unless
special circumstances are present.
Section 50.12(a)(2)(ii) of 10 CFR states that special circumstances
are present when ``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.* * *'' The
licensee's proposed use of Code Case N-514 will be used as an
alternative method for establishing the setpoints for the LTOP systems.
Based on the conservatism that is incorporated into the methods of
Appendix G of Section XI to the ASME Code for calculating P/T limit
curves, it is concluded that permitting the LTOP setpoints to be
established in accordance with the Code Case (e.g., at a level
110% of the limit defined by the P/T limit curves) would
provide an adequate margin of safety against brittle fracture failure
of the reactor pressure vessels. Accordingly, the Commission has
determined that special circumstances as defined in 10 CFR
50.12(a)(2)(ii) exist.
IV
The Commission has determined that, pursuant to 10 CFR 50.12, the
exemption is authorized by law, will not present an undue risk to the
public health and safety and is consistent with the common defense and
security, and is otherwise in the public interest. Therefore, the
Commission hereby grants Pacific Gas and Electric Company an exemption
from the requirements of 10 CFR 50.60 and 10 CFR Part 50, Appendix G,
to establish LTOP setpoints. The licensee will be allowed to use Code
Case N-514 to establish LTOP setpoints to be used in their P/T limit
curves.
Pursuant to 10 CFR 51.32, the Commission has determined that
granting of this exemption will have no significant effect on the
environment (64 FR 23688).
This exemption is effective upon issuance.
Dated at Rockville, Maryland, this 3rd day of May 1999.
For the Nuclear Regulatory Commission.
John A. Zwolinski,
Director, Division of Licensing Project Management, Office of Nuclear
Reactor Regulation.
[FR Doc. 99-11515 Filed 5-6-99; 8:45 am]
BILLING CODE 7590-01-P
