[Federal Register Volume 75, Number 35 (Tuesday, February 23, 2010)]
[Pages 8149-8150]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-3496]



[Docket Nos. STN 50-528, STN 50-529, and STN 50-530; NRC-2010-0058]

Arizona Public Service Company, et al. Palo Verde Nuclear 
Generating Station, Units 1, 2, and 3 Environmental Assessment and 
Finding of No Significant Impact

    The U.S. Nuclear Regulatory Commission (NRC) is considering 
issuance of an exemption from Title 10 of the Code of Federal 
Regulations (10 CFR) Part 50, Appendix G, ``Fracture Toughness 
Requirements,'' for Facility Operating License Nos. NPF-41, NPF-51, and 
NPF-74, issued to the Arizona Public Service Company (APS, or the 
licensee), for operation of the Palo Verde Nuclear Generating Station 
(PVNGS, the facility), Units 1, 2, and 3, respectively, located in 
Maricopa County, Arizona. Therefore, as required by 10 CFR 51.21, the 
NRC is issuing this environmental assessment and finding of no 
significant impact.

Environmental Assessment

Identification of the Proposed Action

    By letter dated February 19, 2009, as supplemented by letter dated 
December 22, 2009, the licensee submitted a license amendment request 
where, among other changes, the licensee requested the use of an 
alternate methodology for calculating the stress intensity factor 
KIM due to internal pressure loading. As specified in the 
NRC safety evaluation approving Combustion Engineering (CE) Topical 
Report NPSD-683-A, Revision 6, ``Development of a RCS [Reactor Coolant 
System] Pressure and Temperature Limits Report (PTLR) for the removal 
of P-T [Pressure Temperature] Limits and LTOP [Low-Temperature 
Overpressure Protection] Requirements from the Technical 
Specifications,'' dated March 16, 2001, the licensee's application 
included a request for an exemption from the requirements of 10 CFR 
Part 50, Appendix G for pressure temperature (P-T) limits, since the 
alternate methodology applies the CE Nuclear Steam Supply System method

[[Page 8150]]

for calculating KIM stress intensity values.
    The proposed action would exempt the licensee from certain 
requirements of Appendix G to 10 CFR Part 50 to allow the application 
of the methodology in CE NPSD-683-A, Revision 6, for the calculation of 
flaw stress intensity factors due to internal pressure loadings 

The Need for the Proposed Action

    The exemption is needed to allow the licensee to use an alternate 
methodology to meet the fracture toughness requirements for the reactor 
coolant pressure boundary. In the considering the exemption request, 
the staff has determined that, pursuant to 10 CFR 50.12(a)(2)(ii), the 
application of the regulation in the particular circumstances is not 
necessary to achieve the underlying purpose of the rule, based on the 
alternate methodology proposed by the licensee. The proposed action 
would revise the currently-approved methodology for P-T limit 
calculations to incorporate the methodology approved for use in CE 
NPSD-683-A, Revision 6. The topical report allows the use of an 
alternate methodology to calculate the flaw stress intensity factors 
due to internal pressure loadings (KIM). Specifically, the 
exemption is needed because the methodology in CE NPSD-683-A, Revision 
6, could not be shown to be conservative with respect to the 
methodology for the determination of KIM provided in 
Editions and Addenda of the American Society of Mechanical Engineers 
Boiler and Pressure Vessel Code (ASME Code), Section XI, Appendix G, 
through the 1995 Edition and 1996 Addenda (the latest Edition and 
Addenda of the ASME Code which had been incorporated into 10 CFR 50.55a 
at the time of the staff's review of CE NPSD-683-A, Revision 6). 
Therefore, the licensee submitted an exemption request, consistent with 
the requirements of 10 CFR 50.60, to apply the KIM 
calculational methodology of CE NPSD-683-A, Revision 6, as part of the 
PVNGS, Units 1, 2, and 3, PTLR methodology.

Environmental Impacts of the Proposed Action

    The NRC has completed its evaluation of the proposed action and 
concludes that the use of the alternate methodology described above 
would provide an adequate margin of safety against brittle failure of 
the reactor pressure vessels at PVNGS, Units 1, 2 and 3. The proposed 
change does not involve any replacement or modification of plant 
components and no changes are proposed in the operation of PVNGS. 
Therefore the staff concludes that the use of an alternate methodology 
as described in the licensee's request would not significantly affect 
plant safety and would not have a significant adverse affect on the 
probability of an accident occurring.
    The proposed action will not result in any non-radiological impacts 
or radiological impacts. The proposed action does not result in changes 
to the operation of the plant and supporting facilities, land use, or 
water use, nor does it result in changes to the quality or quantity of 
non-radiological and radiological effluents. No impacts are expected to 
the air or ambient air quality. No impacts are expected to aquatic or 
terrestrial habitats or species, or to threatened, endangered, or 
protected species. No impacts are expected to historic and cultural 
resources, or to socioeconomic resources. Accordingly, the NRC 
concludes that there are no significant environmental impacts 
associated with the proposed action.
    The details of the staff's safety evaluation will be provided in 
the exemption to 10 CFR 50, Appendix G, which will allow the use of the 
methodology in Topical Report CE NPSD-683-A, Revision 6, to calculate 
the flaw stress intensity factors due to internal pressure loadings 
(KIM). The exemption will be issued in a future letter to 
the licensee.

Environmental Impacts of the 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

    The action does not involve the use of any different resources than 
those previously considered in the Final Environmental Statement for 
the Palo Verde Nuclear Generating Station, Units 1, 2, and 3, NUREG-
0841, dated February 1982.

Agencies and Persons Consulted

    In accordance with its stated policy, on February 12, 2010, the 
staff consulted with the Arizona State official, Mr. Aubrey Godwin of 
the Arizona Radiation Regulatory Agency, 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 
    For further details with respect to the proposed action, see the 
licensee's letters dated February 19 and December 22, 2009 (Agencywide 
Documents Access and Management System (ADAMS) Accession Nos. 
ML090641014 and ML10040069, respectively). Documents may be examined, 
and/or copied for a fee, at the NRC's Public Document Room (PDR), 
located at One White Flint North, Public File Area O1 F21, 11555 
Rockville Pike (first floor), Rockville, Maryland. Publicly available 
records will be accessible electronically from the ADAMS Public 
Electronic Reading Room on the Internet at the NRC Web site, http://www.nrc.gov/reading-rm/adams.html. Persons who do not have access to 
ADAMS or who encounter problems in accessing the documents located in 
ADAMS should contact the NRC PDR Reference staff by telephone at 1-800-
397-4209 or 301-415-4737, or send an e-mail to [email protected].

    Dated at Rockville, Maryland, this 16th day of February 2010.

    For the Nuclear Regulatory Commission.
James R. Hall,
Senior Project Manager, Plant Licensing Branch IV, Division of 
Operating Reactor Licensing, Office of Nuclear Reactor Regulation.
[FR Doc. 2010-3496 Filed 2-22-10; 8:45 am]