[Federal Register Volume 70, Number 52 (Friday, March 18, 2005)]
[Pages 13215-13216]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-5366]



[Docket Nos. 50-424 and 50-425]

Southern Nuclear Operating Company, Vogtle Electric Generating 
Plant, Units 1 and 2; 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, for Renewed Facility 
Operating License Nos. NPF-68 and NPF-81, issued to Southern Nuclear 
Operating Company (the licensee), for operation of the Vogtle Electric 
Generating Plant (Vogtle), Units 1, and 2, located in Waynesboro, 
Georgia. 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: The proposed action would 
exempt the licensee from the requirements of 10 CFR part 50, Appendix 
G, footnote 2 to table 1, and allow the licensee to use the methodology 
in Westinghouse Commercial Atomic Power Report (WCAP), WCAP-16142, 
Revision 1, ``Reactor Vessel Closure Head/Vessel Flange Requirements 
Evaluation for Vogtle Units 1 and 2,'' to justify eliminating the 
reactor vessel/head flange region when determining pressure-temperature 
(P-T) limits for the reactor vessel.
    The proposed action is in accordance with the licensee's 
application dated February 26, 2004, as supplemented on July 8, and 
October 22, 2004.
    The Need for the Proposed Action: Appendix G of 10 CFR part 50, 
contains requirements for P-T limits for the primary system, and 
requirements for metal temperature of the closure head flange and 
vessel flange regions. The P-T limits are to be determined using the 
methodology of American Society of Mechanical Engineers Boiler and 
Pressure Vessel Code (ASME Code), Section XI, Appendix G, but the 
flange temperature requirements are specified in 10 CFR part 50, 
Appendix G. This rule states that the metal temperature at the closure 
flange regions must exceed the material unirradiated RTNDT 
by at least 120 [deg]F for normal operation when the pressure exceeds 
20 percent of the pre-service hydrostatic test pressure.
    This requirement was originally based on concerns about the 
fracture margin in the closure flange region. During the boltup 
process, outside surface stresses in this region typically reach over 
70 percent of the steady state stress, without being at steady state 
temperature. The margin of 120 [deg]F and the pressure limitation of 20 
percent of hydrostatic pressure were developed in the mid-1970s using 
the Kla fracture toughness to ensure that appropriate 
margins would be maintained.
    Improved knowledge of fracture toughness and other issues that 
affect the integrity of the reactor vessel have led to the recent 
change to allow the use of Klc in the development of P-T 
curves, as contained in ASME Code Case N-640, ``Alternative Reference 
Fracture Toughness for Development of P-T Limit Curves for Section XI, 
Division 1.'' ASME Code Case, N-640 has been approved for use without 
conditions by the NRC staff in Regulatory Guide 1.147, ``Inservice 
Inspection Code Case Acceptability, ASME Section XI, Division 1,'' 
published in June 2003.
    However, P-T limit curves can still produce operational constraints 
by limiting the operational range available to the operator during 
heatup and cooldown of the plant, especially when considering 
requirements in the closure head flange and the vessel flange regions. 
Implementing the P-T curves that use Klc material fracture 
toughness without exempting the flange requirement of 10 CFR part 50, 
Appendix G, would place a restricted

[[Page 13216]]

operating window in the temperature range associated with the closure 
head flange and reactor vessel flange, without a commensurate increase 
in plant safety.
    Environmental Impacts of the Proposed Action: The NRC has completed 
its safety evaluation of the proposed action and concludes that the 
more conservative minimum temperature requirements related to footnote 
(2) to Table 1 of 10 CFR part 50, Appendix G are not necessary to meet 
the underlying intent of 10 CFR part 50, Appendix G, to protect the 
Vogtle, Units 1 and 2 RPVs from brittle fracture during normal 
operation under both core critical and core non-critical conditions and 
RPV hydrostatic and leak test conditions.
    The details of the NRC staffs safety evaluation will be provided in 
the amendment and exemption that will be issued as part of letter to 
the licensee approving the amendment and exemption to the regulation.
    The proposed action will not significantly increase the probability 
or consequence of accidents, no changes are being made in the types of 
effluents that may be released off-site, 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 non-radiological impacts, the proposed 
action does not have a potential to affect any historic sites. It does 
not affect non-radiological plant effluents and has no other 
environmental impact. Therefore, there are no significant 
nonradiological environmental impacts associated with the proposed 
    Accordingly, the NRC concludes that there are no significant 
environmental impacts associated with the proposed action.
    Environmental Impacts of the Alternatives to the Proposed Action: 
As an alternative to the proposed action, the NRC 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 resource than those previously considered in NUREG-
1087, ``Final Environmental Statement related to the operation of the 
Vogtle Electric Generating Plant, Units 1 and 2,'' dated December 1985.
    Agencies and Persons Consulted: On January 6, 2005, the NRC staff 
consulted with the Georgia State official, Mr. Jim Hardeman of the 
Department of 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 
    For further details with respect to the proposed action, see the 
licensee's letter dated February 26, 2004, as supplemented on July 8, 
and October 22, 2004. 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 Agencywide Documents Access and 
Management System (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 by 
e-mail to [email protected].

    Dated at Rockville, Maryland, this 10th day of March, 2005.

    For the Nuclear Regulatory Commission.
John Nakoski,
Chief, Section 1, Project Directorate II, Division of Licensing Project 
Management, Office of Nuclear Reactor Regulation.
[FR Doc. 05-5366 Filed 3-17-05; 8:45 am]