[Federal Register Volume 67, Number 38 (Tuesday, February 26, 2002)]
[Notices]
[Pages 8826-8827]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-4518]


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NUCLEAR REGULATORY COMMISSION

[Docket No. 50-334]


FirstEnergy Nuclear Operating Company, Beaver Valley Power 
Station, Unit No. 1; Exemption

1.0  Background

    The FirstEnergy Nuclear Operating Company (FENOC/the licensee) is 
the holder of Facility Operating License No. DPR-66 which authorizes 
operation of Beaver Valley Power Station, Unit No. 1 (BVPS-1). 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 pressurized-water reactor located in 
Beaver County, Pennsylvania.

2.0  Discussion

    Title 10 of the Code of Federal Regulations (10 CFR), Section 
50.60(a), requires that ``all light-water nuclear power reactors . . . 
must meet the fracture toughness and material surveillance program 
requirements for the reactor coolant pressure boundary set forth in 
appendices G and H to this part.'' 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, Appendix G to 10 CFR 
part 50 states that ``[t]he appropriate requirements on * * * the 
pressure-temperature limits and minimum permissible temperature must be 
met for all conditions.'' Further, Appendix G of 10 CFR Part 50 
specifies that the requirements for these limits are based on the 
application of evaluation procedures given in Appendix G to Section XI 
of the American Society of Mechanical Engineers (ASME) Code. In this 
exemption, consistent with the current provisions of 10 CFR 50.55(a), 
all references made to the ASME Code denote the 1995 Edition of the 
ASME Code, including the 1996 Addenda.
    In order to support a proposed amendment to the BVPS-1 Technical 
Specification (TS) P-T limit curves, FENOC requested in its application 
dated June 29, 2001, that the staff exempt BVPS-1 from application of 
specific requirements of 10 CFR Part 50, Section 50.60(a), and 10 CFR 
Part 50, Appendix G, and substitute use of ASME Code Case N-640. ASME 
Code Case N-640 permits the use of an alternate reference fracture 
toughness curve for RPV materials for use in determining the P-T 
limits. The proposed exemption is consistent with, and is needed to 
support, the BVPS-1 TS amendment request that was contained in the same 
application. The proposed BVPS-1 TS amendment will revise the P-T 
limits for heatup, cooldown, and inservice test limitations for the 
reactor coolant system (RCS) to 22 effective full power years (EFPYs).
    The proposed TS amendment to revise the P-T limits for BVPS-1 
relies in part on the requested exemption. These revised P-T limits 
have been developed using the lower bound KIC fracture 
toughness curve shown in ASME Code Section XI, Appendix A, Figure A-
2200-1, as the basis fracture toughness curve for defining the BVPS-1 
P-T limits in lieu of using the lower bound KIA fracture 
toughness curve of ASME Code Section XI, Appendix G, Figure G-2210-1. 
The other margins involved with the ASME Code, Section XI, Appendix G, 
process of determining P-T limit curves remain unchanged.
    Use of the KIC curve as the basis fracture toughness 
curve for the development of P-T operating limits is more technically 
correct than use of the KIA curve. The KIC curve 
appropriately implements the use of a relationship based on static 
initiation fracture toughness behavior to evaluate the controlled 
heatup and cooldown process of an RPV, whereas the KIA 
fracture toughness curve codified into Appendix G to Section XI of the 
ASME Code was developed from more conservative crack arrest and dynamic 
fracture toughness test data. The application of the KIA 
fracture toughness curve was initially codified in Appendix G to 
Section XI of the ASME Code in 1974 to provide a conservative 
representation of RPV material fracture toughness. This initial 
conservatism was necessary due to the limited knowledge of RPV material 
behavior in 1974. However, additional knowledge has been gained about 
RPV materials which demonstrates that the lower bound on fracture 
toughness provided by the KIA fracture toughness curve is 
well beyond the margin of safety required to protect public health and 
safety from potential RPV failure. In addition, P-T limit curves based 
on the KIC fracture toughness 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. The 
operating window through which the operator heats up and cools down the 
RCS is determined by the difference between the maximum allowable 
pressure determined by Appendix G of ASME Code, Section XI, and the 
minimum required pressure for the reactor coolant pump (RCP) seals 
adjusted for instrument uncertainties. A narrow operating window could 
potentially have an adverse safety impact by increasing the possibility 
of inadvertent overpressure protection system (OPPS) actuation. This 
OPPS actuation could be caused by pressure surges associated with 
normal plant evolutions such as starting RCS pumps or switching 
operating charging pumps while the RCS is in a water-solid condition.
    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 BVPS-1 with 
these P-T curves without the relief provided by ASME Code Case N-640 
may unnecessarily restrict the P-T operating window, especially at low-
temperature conditions. The operating window becomes more restrictive 
with continued reactor vessel service. Therefore, the licensee 
concluded that these considerations were special circumstances pursuant 
to 10 CFR 50.12(a)(2)(iii), regarding undue hardship, and requested the 
exemption to use the provisions of ASME Code Case N-640 in the 
development of BVPS-1 RPV P-T limit curves.
    The Nuclear Regulatory Commission (NRC) staff has reviewed the 
exemption request submitted by FENOC and has concluded that an 
exemption should be granted to permit the licensee to use the 
provisions of ASME Code Case N-640 for the purpose of developing BVPS-1 
RPV P-T limit curves. However, the

[[Page 8827]]

NRC staff does not agree with the special circumstances cited by FENOC 
in its June 29, 2001, application regarding the basis for granting the 
exemption. The NRC staff did not conclude that the circumstances cited 
above constitute ``undue hardship or other costs that are significantly 
in excess of those contemplated when the regulation was adopted, or 
that are significantly in excess of those incurred by others similarly 
situated,'' pursuant to 10 CFR 50.12(a)(2)(iii). Rather, the NRC staff 
concluded that the application of the technical provisions of ASME Code 
Case N-640 provided sufficient margin in the development of RPV P-T 
limit curves such that the underlying purpose of the regulations, 
Appendix G to 10 CFR Part 50, will continue to be met and that the 
specific conditions required by the regulations (i.e., use of all 
provisions in Appendix G to Section XI of the ASME Code) were not 
necessary. Therefore, the NRC staff grants the requested exemption to 
FENOC based on the special circumstances of 10 CFR 50.12(a)(2)(ii), 
``[a]pplication of the regulation in the particular circumstances would 
not serve the underlying purpose of the rule or is not necessary to 
achieve the underlying purpose of the rule.''
    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 
application of ASME Code Case N-640, while maintaining, pursuant to 10 
CFR 50.12(a)(2)(ii), the underlying purpose of the ASME Code and the 
NRC regulations to ensure an acceptable margin of safety.

3.0 Evaluation

    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 NRC staff accepts the 
licensee's determination that an exemption would be required to approve 
the use of ASME Code Case N-640. The NRC staff concluded that the use 
of ASME Code Case N-640 would meet the underlying intent of Appendix G 
to 10 CFR part 50.
    Based upon a consideration of the conservatism that is explicitly 
incorporated into the methodologies of Appendix G to 10 CFR part 50, 
Appendix G to Section XI of the ASME Code, and RG 1.99, Revision 2, the 
staff concluded that application of ASME Code Case N-640 as described 
would provide an adequate margin of safety against brittle failure of 
the RPV. This conclusion 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 granting the exemption under 
the special circumstances of 10 CFR 50.12(a)(2)(ii) is appropriate and 
that the methodology of ASME Code Case N-640 may be used to revise the 
P-T limits for the BVPS-1 RCS.

4.0 Conclusion

    Accordingly, the Commission has determined that, pursuant to 10 CFR 
50.12(a), the exemption is authorized by law, will not present an undue 
risk to the public health and safety, and is consistent with the common 
defense and security. Also, special circumstances are present. 
Therefore, the Commission hereby grants First Energy Nuclear Operating 
Company an exemption from the requirements of 10 CFR 50.60(a), and 10 
CFR part 50, Appendix G, for the development of P-T limit curves for 
the BVPS-1 reactor coolant system.
    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 (67 FR 7405).
    This exemption is effective upon issuance.

    Dated at Rockville, Maryland, this 19th day of February 2002.

    For the Nuclear Regulatory Commission.
John A. Zwolinski,
Director, Division of Licensing Project Management, Office of Nuclear 
Reactor Regulation.
[FR Doc. 02-4518 Filed 2-25-02; 8:45 am]
BILLING CODE 7590-01-P