[Federal Register Volume 66, Number 88 (Monday, May 7, 2001)]
[Notices]
[Pages 23051-23052]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-11388]


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NUCLEAR REGULATORY COMMISSION

[50-305]


Nuclear Management Company, LLC; Kewaunee Nuclear Power Plant; 
Exemption

1.0  Background

    Nuclear Management Company, LLC (the licensee) is the holder of 
Facility Operating License No. DPR-43, which authorizes operation of 
the Kewaunee Nuclear Power Plant (KNPP). The license provides, among 
other things, that the facility is subject to all rules, regulations, 
and orders of the U.S. Nuclear Regulatory Commission (the Commission) 
now or hereafter in effect.
    The facility consists of a pressurized water reactor located on the 
licensee's KNPP site in Kewaunee County, Wisconsin.

2.0  Request

    By letter dated June 7, 1999, as supplemented February 4, September 
26, December 18, 2000, and March 12, 2001, Wisconsin Public Service 
Corporation (WPSC) proposed three exemptions and a license amendment 
which affect the licensing basis of the KNPP reactor pressure vessel 
(RPV). Subsequently, WPSC was succeeded by Nuclear Management Company, 
LLC (NMC), as the licensed operator of the KNPP. By letter dated 
October 5, 2000, NMC (the licensee) requested the Nuclear Regulatory 
Commission (NRC) staff continue to process and disposition licensing 
actions previously docketed and requested by WPSC. By letter dated 
December 18, 2000, the licensee withdrew the license amendment.
    The three exemptions requested by the licensee address portions of 
the following regulations: (1) Appendix G to 10 CFR Part 50, which sets 
forth fracture toughness requirements for ferritic materials of 
pressure-retaining components of the reactor coolant pressure boundary 
of light water nuclear power reactors to provide adequate margins of 
safety during any condition of normal operation, including anticipated 
operational occurrences and system hydrostatic tests, to which the 
pressure boundary may be subjected over its service lifetime; (2) 10 
CFR 50.61, which sets forth fracture toughness requirements for 
protection against pressurized thermal shock (PTS) events; and (3) 
Appendix H to 10 CFR Part 50, which requires the establishment of a RPV 
material surveillance program.
    The licensee requested an exemption from Appendix G to 10 CFR Part 
50 to replace the required use of the existing Charpy V-notch and drop 
weight-based methodology and allow the use an alternate methodology to 
incorporate the use of fracture toughness test data for evaluating the 
integrity of the KNPP RPV circumferential beltline weld based on the 
use of the 1997 Edition of American Society for Testing and Materials 
(ASTM) Standard Test Method E 1921 (E 1921-97) and American Society for 
Mechanical Engineering (ASME) Code Case N-629. The exemption is 
required since Appendix G to 10 CFR Part 50, through reference to 
Appendix G to Section XI of the ASME Code pursuant to 10 CFR 50.55(a), 
requires the use of a methodology based on Charpy V-notch and drop 
weight data.
    The licensee requested an exemption from 10 CFR 50.61 to use an 
alternate methodology to allow the use of fracture toughness test data 
for evaluating the integrity of the KNPP RPV circumferential beltline 
weld based on the use of the 1997 Edition of ASTM E 1921-97 and ASME 
Code Case N-629. The exemption is required since the methodology for 
evaluating RPV material fracture toughness in 10 CFR 50.61 requires the 
use of the Charpy V-notch and drop weight data for establishing the PTS 
reference temperature (RTPTS).
    The licensee requested an exemption from Appendix H to 10 CFR Part 
50 to modify the basis for the KNPP RPV surveillance program to allow 
the acquisition and use of fracture toughness data instead of the 
Charpy V-notch impact testing required by Appendix H to 10 CFR Part 50. 
The exemption is required since Appendix H to 10 CFR Part 50 does not 
address the testing of surveillance specimens for direct measurement of 
fracture toughness.

3.0  Discussion

    10 CFR 50.12(a)(2)(ii) enables the Commission to grant exemptions 
from the requirements of Part 50 when special circumstances are present 
such that application 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.
    The underlying purpose of Appendix G to 10 CFR Part 50 is to set 
forth fracture toughness requirements for ferritic materials of 
pressure-retaining components of the reactor coolant pressure boundary 
of light water nuclear power reactors to provide adequate margins of 
safety during any condition of normal operation, including anticipated 
operational occurrences and system hydrostatic tests, to which the 
pressure boundary may be subjected over its service lifetime.
    The methodology underlying the requirements of Appendix G to 10 CFR 
Part 50 is based on the use of Charpy V-notch and drop weight data. The 
licensee proposes to replace the use of the existing Charpy V-notch and 
drop weight-based methodology by a fracture toughness-based methodology 
to demonstrate compliance with Appendix G to 10 CFR Part 50. The NRC 
staff has concluded that the exemption is justified based on the 
licensee utilizing the fracture toughness methodology specified in 
Appendix A of the NRC staff safety evaluation (SE), dated May 1, 2001. 
The use of the methodology specified in Appendix A of the NRC staff SE 
will ensure that P-T limits developed for the KNPP RPV will continue to 
be based on an adequately conservative estimate of RPV material 
properties and ensure that the pressure-retaining components of the 
reactor coolant pressure boundary retain adequate margins of safety 
during any condition of normal operation, including anticipated 
operational occurrences. Also, when additional fracture toughness data 
relevant to the evaluation of the KNPP RPV circumferential weld is 
acquired as part of the KNPP surveillance program, this data must be 
incorporated into the evaluation of the KNPP RPV using the methodology 
of Appendix A of the NRC staff SE. With these conditions, which were 
agreed to by licensee letter, dated March 12, 2001, the licensee's 
requested exemption from the use of the Charpy V-notch and drop weight-
based methodology required by Appendix G to 10 CFR Part 50 may be 
granted in accordance with 10 CFR 50.12(ii) in that

[[Page 23052]]

special circumstances are present since application of the regulation 
in the particular circumstances is not necessary to achieve the 
underlying purpose of the rule. The foregoing exemption only modifies 
the methodology to be used by the licensee for demonstrating compliance 
with the requirements of Appendix G to 10 CFR Part 50, and does not 
exempt the licensee from meeting any other requirement of Appendix G to 
10 CFR Part 50.
    The underlying purpose of 10 CFR 50.61 is to establish requirements 
which ensure that a licensee's RPV will be protected from failure 
during a PTS event by evaluating the fracture toughness of RPV 
materials.
    The licensee seeks an exemption to 10 CFR 50.61 requirement to use 
a methodology for the ``determination of adjusted/indexing reference 
temperatures.'' The licensee proposes to use ASME Code Case N-629 and 
the methodology outlined in its submittal, which are based on the use 
of fracture toughness data, as an alternative to the Charpy V-notch and 
drop weight-based methodology required by 10 CFR 50.61 for establishing 
the PTS RTPTS. The NRC staff has concluded that the 
exemption is justified based on the licensee utilizing the methodology 
specified in Appendix A of the NRC staff SE, dated May 1, 2001. The use 
of the methodology specified in Appendix A of the NRC staff SE will 
ensure the PTS evaluation developed for the KNPP RPV will continue to 
be based on an adequately conservative estimate of RPV material 
properties and ensure the RPV will be protected from failure during a 
PTS event. Also, when additional fracture toughness data relevant to 
the evaluation of the KNPP RPV circumferential weld is acquired as part 
of the KNPP surveillance program, this data must be incorporated into 
the evaluation of the KNPP RPV using the methodology of Appendix A of 
the NRC staff SE. With these conditions, which were as agreed to by 
licensee letter, dated March 12, 2001, the licensee's requested 
exemption from the use of the Charpy V-notch and drop weight-based 
methodology required by 10 CFR 50.61 may be granted in accordance with 
10 CFR 50.12(ii) in that special circumstances are present since 
application of the regulation in the particular circumstances is not 
necessary to achieve the underlying purpose of the rule. The foregoing 
exemption only modifies the methodology to be used by the licensee for 
demonstrating compliance with the requirements of 10 CFR 50.61, and 
does not exempt the licensee from meeting any other requirement of 10 
CFR 50.61.
    Appendix H to 10 CFR Part 50 requires that, ``[f]or each capsule 
withdrawal, the test procedures and reporting requirements must meet 
the requirements of ASTM E 185-82 [the 1982 edition] to the extent 
practicable for the configuration of the specimens in the capsule.'' 
ASTM Standard Practice E 185-82 requires Charpy V-notch impact testing, 
but does not address the testing of surveillance specimens for direct 
measurement of fracture toughness, either as a requirement or as an 
optional action. The exemption would permit the licensee to utilize 
alternative surveillance program testing requirements and permit the 
acquisition of fracture toughness data for the surveillance weld as the 
basis for the KNPP RPV surveillance program.
    The underlying purpose of Appendix H to 10 CFR Part 50 is to 
acquire data to, ``* * *  monitor changes in the fracture toughness 
properties of ferritic materials in the reactor vessel beltline region 
of light water nuclear power reactors which result from exposure of 
these materials to neutron irradiation and the thermal environment.'' 
As discussed in the NRC staff SE, dated May 1, 2001, the licensee's 
alternate surveillance program requirements and the acquisition of data 
will adequately monitor the change in RPV fracture toughness and 
provide input to the approved fracture toughness-based methodology for 
RPV integrity. Therefore, the NRC staff concludes that this exemption 
may be granted because the special circumstances required by 10 CFR 
50.12(a)(ii) are present in that application of the regulation [i.e., 
the Charpy V-Notch-based testing practices specified by Appendix H to 
10 CFR Part 50] in the particular circumstances is not necessary to 
achieve the underlying purpose of the rule.

4.0  Conclusion

    Accordingly, the Commission has determined that, pursuant to 10 CFR 
50.12(a), the exemptions are 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 Nuclear 
Management Company, LLC, exemptions from portions of the requirements 
of Appendix G to 10 CFR Part 50; 10 CFR 50.61; and, Appendix H to 10 
CFR Part 50, to allow an alternative methodology that is based on using 
of fracture toughness test data for evaluating the integrity of the 
KNPP RPV circumferential beltline weld with the following conditions:
    (1) The licensee must utilize the methodology specified in Appendix 
A of the NRC staff SE, dated May 1, 2001;
    (2) When additional fracture toughness data relevant to the 
evaluation of the KNPP RPV circumferential weld is acquired as part of 
the KNPP surveillance program, this data must be incorporated into the 
evaluation of the KNPP RPV using the methodology of Appendix A of the 
NRC staff SE; and
    (3) The licensee must obtain the following regarding the next 
surveillance capsule: (a) a valid measurement of the fracture 
toughness-based T0 parameter for the KNPP RPV surveillance 
weld, (b) an estimate of the Charpy V-notch 30 ft-lb transition 
temperature shift for the surveillance weld, and (c) an estimate of the 
upper shelf energy drop for the surveillance weld.
    Pursuant to 10 CFR 51.32, an environmental assessment and finding 
of no significant impact has been prepared and published in the Federal 
Register (66 FR 21787). Accordingly, based upon the environmental 
assessment, the Commission has determined that the granting of this 
exemption will not result in any significant effect on the quality of 
the human environment.
    This exemption is effective upon issuance.

    Dated at Rockville, Maryland, this 1st day of May 2001.

For the Nuclear Regulatory Commission.
John A. Zwolinski,
Director, Division of Licensing Project Management, Office of Nuclear 
Reactor Regulation.
[FR Doc. 01-11388 Filed 5-4-01; 8:45 am]
BILLING CODE 7590-01-P