[Federal Register Volume 65, Number 142 (Monday, July 24, 2000)]
[Notices]
[Pages 45628-45629]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-18656]


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NUCLEAR REGULATORY COMMISSION

[DOCKET NO. 50-400]


Carolina Power & Light Company; Shearon Harris Nuclear Power 
Plant, Unit 1, Environmental Assessment and Finding of No Significant 
Impact

    The U.S. Nuclear Regulatory Commission (NRC) is considering 
issuance of an exemption from certain requirements of Title 10 of the 
Code of Federal Regulations (10 CFR) Part 50, Section 50.60(a) for 
Facility Operating License No. NPF-63, issued to Carolina Power & Light 
Company (CP&L, the licensee) for operation of the Shearon Harris 
Nuclear Power Plant, Unit 1 (HNP), located in Wake and Chatham 
Counties, North Carolina.

Environmental Assessment

Identification of the Proposed Action

    10 CFR Part 50, Appendix G, requires that pressure-temperature (P-
T) limits be established for reactor pressure vessels (RPVs) during 
normal operating and hydrostatic or leak testing conditions. 
Specifically, 10 CFR Part 50, Appendix G, states that, ``[t]he 
appropriate requirements on both the pressure-temperature limits and 
the minimum permissible temperature must be met for all conditions.'' 
Appendix G of 10 CFR Part 50 specifies that the requirements for these 
limits are the American Society of Mechanical Engineers (ASME) Boiler 
and Pressure Vessel Code (Code), Section XI, Appendix G Limits.
    To address provisions of amendments to the technical specifications 
(TS) P-T limits and low temperature overpressure protection (LTOP) 
system setpoints, the licensee requested in its submittal dated April 
12, 2000, as supplemented on June 2, 2000, that the staff exempt HNP 
from application of specific requirements of 10 CFR Part 50, Section 
50.60(a) and Appendix G, and substitute use of ASME Code Case N-640. 
Code Case N-640 permits the use of an alternate reference fracture 
toughness (KIC fracture toughness curve instead of 
Kla fracture toughness curve) for reactor vessel materials 
in determining the P-T limits and LTOP setpoints. Since the 
KIC fracture toughness curve shown in

[[Page 45629]]

ASME Section XI, Appendix A, Figure A-2200-1 (the KIC 
fracture toughness curve) provides greater allowable fracture toughness 
than the corresponding Kla fracture toughness curve of ASME 
Section XI, Appendix G, Figure G-2210-1 (the Kla fracture 
toughness curve), using Code Case N-640 for establishing the P-T limits 
and LTOP setpoints would be less conservative than the methodology 
currently endorsed by 10 CFR Part 50, Appendix G and, therefore, an 
exemption to apply the Code Case would be required by 10 CFR 50.60. It 
should be noted that, although Code Case N-640 was incorporated into 
the ASME Code recently, an exemption is still needed because the 
proposed P-T limits and LTOP setpoints (excluding Code Cases N-640) are 
based on the 1989 edition of the ASME Code.
    The proposed action is in accordance with the licensee's 
application for exemption dated April 12, 2000, as supplemented on June 
2, 2000.

The Need for the Proposed Action

    Use of the Klc curve, Code Case N-640, in determining 
the lower bound fracture toughness in the development of P-T operating 
limit curves and LTOP setpoints is more technically correct than use of 
the Kla curve since the rate of loading during a heatup or 
cooldown is slow and is more representative of a static condition than 
a dynamic condition. The Klc curve appropriately implements 
the use of static initiation fracture toughness behavior to evaluate 
the controlled heatup and cooldown process of a reactor vessel. The 
staff has required use of the conservatism of the Kla curve 
since 1974, when the curve was adopted by the ASME Code. This 
conservatism was initially necessary due to the limited knowledge of 
the fracture toughness of RPV materials at that time. Since 1974, 
additional knowledge has been gained about RPV materials, which 
demonstrates that the lower bound on fracture toughness provided by the 
Kla curve greatly exceeds the margin of safety required to 
protect the public health and safety from potential RPV failure. In 
addition, P-T curves and LTOP setpoints based on the Klc 
curve will enhance overall plant safety by opening the P-T operating 
window, with the greatest safety benefit in the region of low 
temperature operations.
    Since an unnecessarily reduced P-T operating window can reduce 
operator flexibility without just basis, implementation of the proposed 
P-T curves and LTOP setpoints as allowed by ASME Code Case N-640 may 
result in enhanced safety during critical plant operational periods, 
specifically heatup and cooldown conditions. Thus, pursuant to 10 CFR 
50.12(a)(2)(ii), the underlying purpose of 10 CFR 50.60 and Appendix G 
to 10 CFR Part 50 will continue to be served.

Environmental Impacts of the Proposed Action

    The NRC has completed its evaluation of the proposed action and 
concludes that the exemption described above would provide an adequate 
margin of safety against brittle failure of the HNP reactor pressure 
vessel.
    The proposed action will not increase the probability or 
consequences of accidents, no changes are being made in the types of 
any effluents that may be released offsite, and there is no significant 
increase in occupational or public radiation exposure. Therefore, there 
are no significant radiological environmental impacts associated with 
the proposed action.
    With regard to potential nonradiological environmental impacts, the 
proposed action does not involve any historic sites. It does not affect 
nonradiological plant effluents and has no other environmental impacts. 
Therefore, there are no significant nonradiological impacts associated 
with the proposed action.
    Accordingly, the NRC concludes that there are no significant 
environmental impacts associated with the proposed action.

Alternatives to the Proposed Action

    As an alternative to the proposed action, the staff considered 
denial of the proposed action (i.e., the ``no-action'' alternative). 
Denial of the application would result in no change in current 
environmental impacts. The environmental impacts of the proposed action 
and the alternative action are similar.

Alternative Use of Resources

    This action does not involve the use of any resources not 
previously considered in the Final Environmental Statement for HNP.

Agencies and Persons Consulted

    In accordance with its stated policy, on July 11, 2000, the staff 
consulted with the North Carolina State official, Mr. Johnny James of 
the North Carolina Department of Environment and Natural Resources, 
regarding the environmental impact of the proposed action. The State 
official had no comments.

Finding of No Significant Impact

    On the basis of the environmental assessment, the NRC concludes 
that the proposed action will not have a significant effect on the 
quality of the human environment. Accordingly, the NRC has determined 
not to prepare an environmental impact statement for the proposed 
action.
    For further details with respect to the proposed action, see the 
licensee's letter dated April 12, 2000, as supplemented on June 2, 
2000, which is available for public inspection at the Commission's 
Public Document Room, The Gelman Building, 2120 L Street, NW., 
Washington, DC. Publicly available records will be accessible 
electronically from the ADAMS Public Library component on the NRC Web 
site, http:\\www.nrc.gov (the Electronic Reading Room).

    Dated at Rockville, Maryland, this 17th day of July 2000.
For the Nuclear Regulatory Commission.
Richard J. Laufer,
Project Manager, Section 2, Project Directorate II, Division of 
Licensing Project Management Office of Nuclear Reactor Regulation.
[FR Doc. 00-18656 Filed 7-21-00; 8:45 am]
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