[Federal Register Volume 59, Number 241 (Friday, December 16, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-30934]


[[Page Unknown]]

[Federal Register: December 16, 1994]


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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-327]

 

Tennessee Valley Authority (Sequoyah Nuclear Plant, Unit 1); 
Exemption

I

    The Tennessee Valley Authority (TVA) is the holder of Facility 
Operating License No. DPR-77, which authorizes operation of the 
Sequoyah Nuclear Plant, Unit 1 (the facility, Unit 1). The license 
provides, among other things, that the facility is subject to all 
rules, regulations, and orders of the Nuclear Regulatory Commission 
(the Commission) now or hereafter in effect.
    The facility consists of a pressurized water reactor located on 
TVA's Sequoyah site in Soddy Daisy, Hamilton County, Tennessee.

II

    Section III.D.3 of Appendix J to 10 CFR Part 50 requires that Type 
C local leak rate tests (LLRTs) be performed during reactor shutdown 
for refueling, or other convenient intervals, but in no case at 
intervals greater than 2 years.
    On March 2, 1993, SQN Unit 1 entered a forced outage and started 
the Cycle 6 refueling outage. All Type B and Type C LLRTs were 
preformed during the outage, which ended in December 1993. The unit 
returned to service on April 20, 1994. Due to the length of the outage, 
a number of LLRTs that were performed early in the outage were 
reperformed prior to conducting the containment integrated leak rate 
test (CILRT) in December 1993. LLRTs of values that were initially 
tested between April 3 and July 19, 1993, however, were not retested 
because of schedule restraints associated with the CILRT. Since the 2-
year time interval for the Type C value pentrations that were not 
retested will expire starting in April 1995, Unit 1 would be forced to 
shut down at that time to perform the tests unless a schedular 
exemption is granted.
    The next Unit 1 refueling outage is scheduled to start in September 
1995. Therefore, the licensee has proposed an exemption to allow a one-
time deferment of the Appendix J interval requirement for the affected 
Type C valve penetration tests from April 3, 1995, until October 1, 
1995, a total of approximately 181 days for the first valve tested 
during the Cycle 6 outage.
    The extension would affect 126 isolation valves of 242 valves in 
the leak rate test program and are listed in the submittal. They are 
considered by the licensee to be leak tight and in good condition, 
which was verified by the leak rate tests performed during the Cycle 5 
refueling outage. Based on the present total integrated containment 
leak rate that accounts for less than 93 percent of the 0.75 La limit, 
the licensee believes that the remaining margin is sufficient to ensure 
that any incremental increase in leakage because of the extension, will 
not result in unacceptable as-found test results. Also, based on 
historical data, the licensee believes that any incremental increase in 
leakage from these valves because of the extension would be small. In 
addition, the valves were included in the boundary for the Last Type A 
test that was performed in December 1993, and have been subjected to 
improved maintenance practices that provide increased assurance that 
they will be capable of performing their intended safety function.

III

    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. Special circumstances are 
present whenever, according to 10 CFR 50.12(a)(2)(ii), ``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 the requirement to perform Type C 
containment leak rate tests at intervals not to exceed 2 years, is to 
ensure that any potential leakage pathways through the containment 
boundary are identified within a time span that prevents significant 
degradation from continuing or being unknown, and long enough to allow 
the tests to be conducted during scheduled refueling outages. This 
interval was originally published in Appendix J when refueling cycles 
were conducted at approximately annual intervals and has not been 
changed to reflect 18-month or 2-year operating cycles. It is not the 
intent of the regulation to require a plant shutdown solely for the 
purpose of conducting the periodic leak rate tests. Based on historical 
data at SQN, any incremental increase in leakage because of the 
extension would be small. Improved maintenance practices implemented 
during the Unit 1 Cycle 5 outage, and continued in the Unit 1 Cycle 6 
outage, provide increased assurance that these components will perform 
their safety function. Therefore, since the maximum extension is 
relatively short (approximately 181 days for the first valve tested 
during the Cycle 6 outage) compared to the 2-year test interval 
requirement, it is unlikely that substantial degradation of the valves 
leading to the failure of the containment to perform its safety 
function would occur. As a result, the application of the regulation in 
the particular circumstances is not necessary to achieve the underlying 
purpose of the rule.

IV

    For the foregoing reasons, the NRC staff has concluded that the 
licensee's proposed increase of the 2-year time interval for performing 
the Type C Leak Rate Tests of the valves specified in the application 
until the Cycle 7 refueling outage will not present an undue risk to 
public health and safety and is consistent with the common defense and 
security. The NRC staff has determined that there are special 
circumstances present, as specified in 10 CFR 50.12(a)(2), such that 
application of 10 CFR Part 50, Appendix J, Section III.D.3 is not 
necessary in order to achieve the underlying purpose of this 
regulation.
    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 the Tennessee 
Valley Authority exemption from the requirements of Section III.D.3 of 
Appendix J to 10 CFR Part 50 for Unit I as requested in the submittal.
    Pursuant to 10 CFR 51.32, the Commission has determined that the 
granting of this exemption will not result in any significant adverse 
environmental impact (59 FR 63387).
    This exemption is effective upon issuance.

    Dated at Rockville, Maryland, this 8th day of December 1994.

    For the Nuclear Regulatory Commission.
Steven A. Varga,
Director, Division of Reactor Projects--I/II, Office of Nuclear Reactor 
Regulation.
[FR Doc. 94-30934 Filed 12-15-94; 8:45 am]
BILLING CODE 7590-01-M