[Federal Register Volume 66, Number 55 (Wednesday, March 21, 2001)]
[Notices]
[Pages 15913-15914]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-6981]


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NUCLEAR REGULATORY COMMISSION

[Docket No. 50-353]


Exelon Generation Company; Limerick Generating Station, Unit 2 
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 Appendix G to 
Part 50 of Title 10 of the Code of Federal Regulations (10 CFR Part 50) 
for Facility Operating License No. NPF-85, issued to Exelon Generation 
Company (Exelon or the licensee) for operation of the Limerick 
Generating Station, Unit 2 (Limerick Unit 2), located in Montgomery and 
Chester Counties in Pennsylvania.

Environmental Assessment

Identification of the Proposed Action

    Appendix G to 10 CFR part 50, requires that pressure-temperature 
(P-T) limits be established for reactor pressure vessels (RPVs) during 
normal operating and hydrostatic or leak rate testing conditions. 
Specifically, 10 CFR part 50, Appendix G, Section IV.A.2.a, states, 
``The 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

[[Page 15914]]

Engineers Boiler and Pressure Vessel Code (ASME Code), Section XI, 
Appendix G, limits.
    To address provisions of amendments to the technical 
specifications' P-T limits, the licensee requested in its submittal 
dated November 20, 2000, as supplemented December 20, 2000, that the 
Nuclear Regulatory Commission (NRC) staff exempt Limerick Unit 2 from 
application of specific requirements of Appendix G to 10 CFR part 50, 
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 
Kia fracture toughness curve) for reactor vessel materials 
in determining the P-T limits. Since the KIC fracture 
toughness curve shown in ASME Code, Section XI, Appendix A, Figure A-
2200-1 (the KIC fracture toughness curve) provides greater 
allowable fracture toughness than the corresponding Kia 
fracture toughness curve of ASME Code, Section XI, Appendix G, Figure 
G-2210-01 (the Kia fracture toughness curve), using Code 
Case N-640 for establishing the P-T limits would be less conservative 
than the methodology currently endorsed by 10 CFR Part 50, Appendix G, 
and therefore, an exemption to Appendix G to apply the Code Case would 
be required.

The Need for the Proposed Action

    ASME Code Case N-640 is needed to revise the method used to 
determine the reactor coolant system (RCS) P-T limits, since continued 
use of the present curves unnecessarily restricts the P-T operating 
window. Since the RCS P-T operating window is defined by the 
P-T operating and test limit curves developed in accordance with the 
ASME Code, Section XI, Appendix G, procedure, continued operation of 
Limerick Unit 2 with these P-T curves without the relief provided by 
ASME Code Case N-640 would unnecessarily require the licensee to 
maintain the RPV at a temperature exceeding 212  deg.F in a limited 
operating window during the pressure test. Consequently, steam vapor 
hazards would continue to be one of the safety concerns for personnel 
conducting inspections in primary containment. Implementation of the 
proposed P-T curves, as allowed by ASME Code Case N-640, would 
eliminate steam vapor hazards by allowing inspections in primary 
containment to be conducted at a lower coolant temperature.

Environmental Impacts of the Proposed Action

    The proposed action would maintain an adequate margin of safety 
against brittle failure of the Limerick Unit 2 RPV.
    The proposed action will not significantly 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 impacts, the proposed 
action does not involve any historic sites. It does not affect 
nonradiological plant effluents and has no other environmental impact. 
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 the 
Limerick Generating Station, Unit 2, dated April 1984.

Agencies and Persons Consulted

    In accordance with its stated policy, on January 19, 2001, the 
staff consulted with the Pennsylvania State official, David Ney of the 
Pennsylvania Department of Environmental Protection, regarding the 
environmental impact of the proposed action. The State official had no 
comments.

Findings 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 November 20, 2000, as supplemented December 20, 
2000. Documents may be examined, and/or copied for a fee, at the NRC's 
Public Document Room, located at One White Flint North, 11555 Rockville 
Pike (first floor) Rockville, Maryland. 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 15th day of March 2001.
    For the Nuclear Regulatory Commission.
Christopher Gratton, Sr.,
Project Manager, Section 2, Project Directorate I, Division of 
Licensing Project Management, Office of Nuclear Reactor Regulation.
[FR Doc. 01-6981 Filed 3-20-01; 8:45 am]
BILLING CODE 7590-01-P