ML20086H976
| ML20086H976 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 07/11/1995 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20086H958 | List: |
| References | |
| NUDOCS 9507180346 | |
| Download: ML20086H976 (3) | |
Text
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L UNITED STATES 1
j NUCLEAR REGULATORY COMMISSION
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.170 TO FACILITY OPERATING LICENSE'NO. DPR-46 NEBRASKA PUBLIC POWER DISTRICT COOPER NUCLEAR STATION
' DOCKET NC.30-298
1.0 INTRODUCTION
By letter dated May 2, 1995, the Nebraska Public Power District (NPPD, the licensee) submitted a request for a license amendment to revise the Technical Specifications. (TSs) for the Cooper Nuclear Station (CNS).
In that letter, the licensee requested a change-to TS Surveillance Requirement 4.7.A.2.f.1,.
which specifies the conditions and frequency for local leak rate testing of
. primary containment penetrations and isolation valves 'in accordance with 10 CFR Part 50, Appendix J.
The change would permit a one-time schedular extension to the 2-year Type B leak testing interval, to allow deferral of the testing of two primary containment penetrations, the drywell head and manport, until the next refueling outage. The two penetrations are currently required 4
to be leak tested by July 17, 1995, when the plant is expected to be operating at full power; the amendment would allow the testing to be performed during Refueling Outage No.16, commencing on October 13, 1995. The' licensee submitted a related request for exemption from the requirements of 10 CFR Part 50, Appendix J, on December 27, 1994, which is being reviewed by the staff concurrently.
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2.0 BACKGROUND
l Surveillance Requirement (SR) 4.7.A.2.f.1 of the CNS TSs implements the requirements of 10 CFR Part 50, Appendix J for the periodic local leak rate testing of primary containment penetrations and isolation valves.
Section III.D.2(a) of Appendix J to 10 CFR Part 50 requires that Type B local leak rate tests (LLRTs), except for airlocks, be performed during reactor shutdown for refueling, or at other convenient intervals, but in no case at intervals greater than 2 years. Similarly, SR 4.7. A.2.f.1' specifies that LLRTs,
...shall be performed on the primary containment testable penetrations and isolation valves at a pressure of 58 psig during each reactor shutdown for refueling, or other convenient intervals, but in no case at-intervals greater than two years." Type B tests are intended to detect local leaks and to measure leakage across each pressure-containing or leakage-limiting boundary for certain reactor containment penetrations.
.The licensee indicated that the Type B leak tests of the subject penetrations cannot be conducted with the plant at power. During reactor power operation, 9507180346 950711 PDR ADOCK 05000298 P
- the extreme radiation environment prohibits personnel from performing the subject LLRTs or any of the activities associated with these tests (such as the removal and replacement of the shield blocks on the refueling floor). The subject LLRTs are normally performed during refueling outages. Therefore, the licensee would have to initiate a reactor shutdown solely for the purpose of conducting the subject Type B tests in order to comply with the current schedular requirement.
3.0 EVALUATION The proposed change to SR 4.7.A.2.f.1 would add a footnote to indicate that the 2-year interval requirement for Penetrations DWH and X-4 (Drywell Head and Manport) may be extended until completion of Refueling Outage No. 16 (RE-16).
The licensee cited a number of factors in support of the requested change.
First, the drywell head and manport penetrations have never failed a Type B LLRT in more than 19 years of plant operation.
Second, the current operating cycle for CNS commenced on August 1, 1993, and has included an extended, unplanned outage of nearly 9 months (May 25, 1994, through February 21,1995).
Therefore, the plant will have operated at full power for a maximum of 18 months out of the 27 month period between refueling outages.
The licensee maintains that degradation of the penetration seals would be less likely during periods of plant shutdown, due to the less severe radiation and temperature environment. The licensee also indicated that the subject penetrations are not active components, and therefore, are not subject to active failure criteria.
During the 1994-1995 forced outage, the licensee evaluated the schedular requirements for all Type B and C testing and performed any tests, as needed, with the exception of the subject penetrations.
Because the duration of the forced outage was uncertain, and reactor disassembly was not conducted, the licensee did not attempt to perform the subject tests during that outage, electing to focus its resources on higher priority programmatic and regulatory issues.
However, the staff concludes that the licensee did make a good faith effort to meet the overall requirements of Appendix J.
The 2-year interval for Type B tests specified in Appendix J was instituted to ensure that testing is performed on a sufficient frequency to detect degradation of containment integrity (and initiate corrective action) before such degradation becomes significant, but on a frequency long enough to permit the tests to be performed during regularly scheduled refueling outages.
The proposed TS change would allow continued power operation for less than 3 months without performing the scheduled LLRTs, until the plant is shut down for refueling. Once in the cold shutdown condition, primary containment integrity is not required. The subject tests would then be performed prior to startup from the refueling outage. Based on the test history of these penetrations and the brief period of operation anticipated before shutdown, there is a high degree of confidence that the penetrations will be capable of performing their intended function of assuring containment integrity following
- a postulated accident. Therefore, the staff concludes that the proposed TS change to allow the deferral of the local leak rate testing of the drywell head and manport penetrations from July 17, 1995, until the next refueling
. outage commencing on October 13, 1995, is acceptable.
4.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Nebraska State official was notified of the proposed issuance of the amendment. The State official had no comment.
5.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes surveillance requirements.
The NRC staff has determined that the amendment involves no significant increase in the amounts, and no i
significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a pro-posed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding (60 FR 29879).
Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR Section 51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
6.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, i
that:
(1) there is reasonable assurance that the health and safety of the.
public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
J. R. Hall Date: July 11, 1995 i
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