[Federal Register Volume 68, Number 87 (Tuesday, May 6, 2003)]
[Notices]
[Pages 24024-24025]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-11159]


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NUCLEAR REGULATORY COMMISSION

[Docket No. 50-440]


FirstEnergy Nuclear Operating Co., Perry Nuclear Power Plant; 
Exemption

1.0 Background

    The FirstEnergy Nuclear Operating Company (FENOC/ the licensee) is 
the holder of Facility Operating License No. NPF-58 which authorizes 
operation of Perry Nuclear Power Plant (PNPP). The license provides, 
among other things, that the facility is subject to all rules, 
regulations, and orders of the U.S. Nuclear Regulatory Commission (NRC, 
the Commission) now or hereafter in effect.
    The facility consists of a boiling water reactor located on FENOC's 
PNPP site, which is located in Lake County, Ohio.

2.0 Request/Action

    Title 10 of the Code of Federal Regulations (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 rate testing conditions. Specifically, 10 CFR 
part 50, Appendix G states that ``[t]he appropriate requirements on * * 
* the pressure-temperature limits and 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 
P-T limits in the submittal dated June 4, 2002, the licensee requested 
that the staff exempt PNPP from application of specific requirements of 
10 CFR part 50, Sec.  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 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 provides greater allowable fracture toughness than the

[[Page 24025]]

corresponding KIa fracture toughness curve of ASME Code, 
Section XI, Appendix G, Figure G-2210-1, using the Kic 
fracture toughness, as permitted by Code Case N-640, in establishing 
the P-T limits would be less conservative than the methodology 
currently endorsed by 10 CFR part 50, appendix G. Considering this, an 
exemption to apply the Code Case would be required by 10 CFR 50.60.
    The licensee proposed to revise the P-T limits for PNPP using the 
KIc fracture toughness curve, in lieu of the KIa 
fracture toughness curve, as the lower bound for fracture toughness.
    Use of the KIc curve in determining the lower bound 
fracture toughness in the development of P-T operating limits curve is 
more technically correct than the KIa 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 
KIc 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 initial conservatism of the KIa curve since 1974 
when the curve was codified. This initial conservatism was necessary 
due to the limited knowledge of RPV materials. Since 1974, additional 
knowledge has been gained about RPV materials, which demonstrates that 
the lower bound on fracture toughness provided by the KIa 
curve is well beyond the margin of safety required to protect the 
public health and safety from potential RPV failure.
    In summary, the ASME Code, Section XI, Appendix G, procedure was 
conservatively developed based on the level of knowledge existing in 
1974, concerning RPV materials and the estimated effects of operation. 
Since 1974, the level of knowledge about these topics has been greatly 
expanded. The NRC staff concurs that this increased knowledge permits 
relaxation of the ASME Code Section XI, Appendix G requirements by 
applying the KIc fracture toughness, as permitted by Code 
Case N-640, because compliance with ASME Code, Section XI, Appendix G 
is not necessary to achieve the underlying purpose of 10 CFR 50.60 and 
part 50, appendix G.

3.0 Discussion

    Pursuant to 10 CFR 50.12, the Commission may, upon application by 
any interested person or upon its own initiative, grant exemptions from 
the requirements of 10 CFR part 50, when (1) the exemptions are 
authorized by law, will not present an undue risk to public health or 
safety, and are consistent with the common defense and security; and 
(2) when special circumstances are present. The staff accepts the 
licensee's determination that an exemption would be required to approve 
the use of Code Case N-640. The staff examined the licensee's rationale 
to support the exemption request and concurred that the use of the Code 
Case N-640 would meet the underlying intent of these regulations. Based 
upon a consideration of the conservatism that is explicitly 
incorporated into the methodologies of 10 CFR part 50, Appendix G; 
Appendix G of the Code; and Regulatory Guide 1.99, ``Radiation 
Embrittlement of Reactor Vessel Material,'' Revision 2, the staff 
concluded that compliance with ASME Code, Appendix G is not necessary 
to achieve the underlying purpose of 10 CFR 50.60 and 10 CFR part 50, 
Appendix G because the application of Code Case N-640 as described 
would provide an adequate margin of safety against brittle failure of 
the RPV. This is also consistent with the determination that the staff 
has reached for other licensees under similar conditions based on the 
same considerations. Therefore, the staff concludes that requesting 
exemption under the special circumstances of 10 CFR 50.12(a)(2)(ii) is 
appropriate and that the methodology of Code Case N-640 may be used to 
revise the P-T limits for PNPP.

4.0 Conclusion

    Accordingly, the Commission has determined that, pursuant to 10 CFR 
50.12(a), the exemption is authorized by law, will not endanger life or 
property or common defense and security, and is, otherwise, in the 
public interest. Therefore, the Commission hereby grants FENOC, 
exemption from the requirements of 10 CFR part 50, Sec.  50.60(a) and 
10 CFR part 50, Appendix G, for PNPP.
    Pursuant to 10 CFR 51.32, the Commission has determined that the 
granting of this exemption will not have a significant effect on the 
quality of the human environment (68 FR 13335).
    This exemption is effective upon issuance.

    Dated at Rockville, Maryland, this 29th day of April 2003.

    For the Nuclear Regulatory Commission.
John A. Zwolinski,
Director, Division of Licensing Project Management, Office of Nuclear 
Reactor Regulation.
[FR Doc. 03-11159 Filed 5-5-03; 8:45 am]
BILLING CODE 7590-01-P