[Federal Register Volume 59, Number 235 (Thursday, December 8, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-30154]
[[Page Unknown]]
[Federal Register: December 8, 1994]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-327]
Tennessee Valley Authority; Sequoyah Nuclear Plant, Unit 1;
Environmental Assessment and Finding of No Significant Impact
The U.S. Nuclear Regulatory Commission (the Commission) is
considering issuance of an exemption from the requirements of Section
III.D.3 of Appendix J to 10 CFR Part 50 to the Tennessee Valley
Authority, licensee for the Sequoyah Nuclear Plant (SQN), Unit 1. The
plant is located at the licensee's site in Hamilton County, Tennessee.
Environmental Assessment
Identification of Proposed Action
The proposed action would exempt the licensee from the provisions
in Section III.D.3 of Appendix J to 10 CFR Part 50 with respect to the
requirement to perform Primary Containment Type C local leak rate tests
(LLRTs) at intervals no greater than 2 years. The exemption would
affect Unit 1 only and allow certain Type C valve penetration LLRTs
that are specified in the submittal (126 valves out of a total of 242
valves subject to the LLRT program) to be delayed until the Cycle 7
refueling outage. This outage is scheduled to start approximately 5
months after the expiration date of the earliest Type C test.
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
performed 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 retested
prior to conducting the containment integrated leak rate test (CILRT)
in December 1993. LLRTs of valves 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 valve penetrations 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 from the first valve tested
during the Cycle 6 outage.
The proposed action is in accordance with the licensee's
application for exemption dated November 10, 1994.
The Need for the Proposed Action
The proposed action is required to exempt the licensee from the
requirement to conduct certain specified Type C containment local leak
rate tests on SQN Unit 1 at a 2-year frequency so the tests can be
performed during the Cycle 7 refueling outage scheduled to start in
September 1995. However, TVA has requested extension of the time
interval to October 1, 1995, to account for unforeseen circumstances.
Environmental Impact of the Proposed Action
With respect to the requested action, exemption from the above
requirement would allow the licensee to delay conducting certain Type C
local leak rate tests at Unit 1 approximately 181 days beyond the
scheduled expiration date of the 2-year period for the first LLRT
performed during the Cycle 6 outage. This relatively small increase in
the test interval does not significantly contribute to the total
leakage limits. The intent of Section III.D.3 of Appendix J is to
ensure that containment leakage is maintained within the prescribed
limits. Based on the following information, the exemption will not
significantly affect the ability of the individual primary containment
valves that are subject to the Type C tests to perform this safety
function:
1. The valves for which the extension of the 2-year interval is
being requested have a history of being leak tight and in good
condition. The leak-tight condition of these components was last
verified by Type C LLRTs and by the Type A test conducted in December
1993. Based on the present containment leak rate that accounts for less
than 93 percent of the 0.75 La limit, the remaining margin is
sufficient to ensure any incremental increase in leakage resulting from
the extension would not cause unacceptable as-found test results.
2. Based on historical data, any incremental increase in leakage
because of the extension will be small. Improved maintenance practices
implemented during the Unit 1 Cycle 5 outage and continued into the
Cycle 6 outage, including motor operated valve testing (MOVATS) of
containment isolation valves, provide increased assurance that these
components will perform their safety function.
3. The valves for which the exemption is requested were included in
the Type A test performed in December 1993. This test indicated a
containment leak rate of 0.1742 percent per day, which is below the
0.1875 percent per day limit.
The change will not increase the probability or consequences of
accidents, no changes are being made in the types of any effluents that
may be released offsite, and there is no significant increase in the
allowable individual or cumulative occupational radiation exposure.
Accordingly, the Commission concludes that there are no significant
radiological environmental impacts associated with the proposed action.
With regard to potential nonradiological environmental impacts, the
proposed action does involve features located entirely within the
restricted area as defined in 10 CFR Part 20. It does not affect
nonradiological plant effluents and has no other environmental impacts.
Accordingly, the Commission concludes that there are no significant
nonradiological impacts associated with the proposed action.
Alternatives to the Proposed Action
Since the Commission has concluded that there is no measurable
environmental impact associated with the proposed exemption, any
alternatives with equal or greater environmental impact need not be
evaluated. The principal alternative would be to deny the request. Such
action would not enhance the protection of the environment and would
result in unjustified cost to the licensee.
Alternative Use of Resources
This action does not involve the use of resources not previously
considered in the ``Final Environmental Statement Related to the
Operation of the Sequoyah Nuclear Plant, Units 1 and 2,'' dated
February 21, 1974.
Agencies and Persons Consulted
The NRC staff consulted with the Tennessee State official regarding
the environmental impact of the proposed action. The State official had
no comments.
Finding of No Significant Impact
Based on the environmental assessment, the Commission concludes
that the proposed action will not have a significant effect on the
quality of the human environment. Accordingly, the Commission has
determined not to prepare an environmental impact statement for the
proposed action.
For further details with respect to the proposed action, see the
licensee's letter dated November 10, 1994, which is available for
public inspection at the Commission's Public Document Room, The Gelman
Building, 2120 L Street, NW., Washington, DC, and at the local public
document room located at the Chattanooga-Hamilton County Library, 1101
Broad Street, Chattanooga, Tennessee 37402.
Dated at Rockville, Maryland, this 2d day of December 1994.
For the Nuclear Regulatory Commission.
Frederick J. Hebdon,
Director, Project Directorate II-4, Division of Reactor Projects--I/II,
Office of Nuclear Reactor Regulation.
[FR Doc. 94-30154 Filed 12-7-94; 8:45 am]
BILLING CODE 7590-01-M