ML17325A773
| ML17325A773 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 06/08/1988 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17325A771 | List: |
| References | |
| NUDOCS 8806170215 | |
| Download: ML17325A773 (3) | |
Text
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O UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO RE VEST FOR CODE RELIEF EXTENSION FOR RHR SYSTEM VALVES INDIANA MICHIGAN POWER COMPANY DONALD C.
COOK NUCLEAR PLANT UNITS NOS.
18(2 DOCKETS NOS.
50-315 AND 50-316 INTRODUCTION By letter dated October 31, 1986, the Indiana Michigan Power Company (the licensee) requested permanent relief from testing of certain valves in its Inservice Testing (IST) program.
These valves, IM0-330, -333., -340, and -350, are presently subject to quarterly testing in accordance with ASME Code Section XI requirements.
The licensee contended that testing of these valves in the present test configuration would place the plant in an unanalyzed condition, would require the plant to enter into Technical Specification
- 3. 0. 3 with only 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> to complete the test, and because the test has historically taken longer than an hour, might require a plant shutdown.
As a result, the licensee requested permanent relief from quarterly testing of these valves, and proposed to test them during cold shutdowns and refueling outages.
In an NRC letter dated December 19, 1986, the licensee was informed that its request for permanent relief was denied but an interim relief was granted until next respective plant scheduled refueling outages.
The letter also stated that for further consideration of the permanent relief, the licensee should submit for NRC review the results ot additional analysis on the unanalyzed condition and/or develop alternative testing methods.
By letter dated November 20, 1987, the licensee requested an extension of the interim relief until the ECCS reanalysis was completed.
The licensee had completed part of the requested analysis but required more time to complete the last portion of this analysis pertaining to containment long-term pressure.
The extension was needed because the interim relief for Unit 1 had expired with the refueling outage which occurred in October
- 1987, and the interim relief for Unit 2 would expire during the next refueling outage scheduled for April 1988.
No further relief was needed for Unit 2 since the outage will last approximately one year to replace all four steam generators.
By letter dated December 11, 1987, the NRC staff granted the requested relief for Unit 1 until June 30, 1988.
Sy letter dated January 18, 1988, the licensee provided the NRC staff with a proposed agenda and schedule for completing the containment long-term pressure analysis.
The licensee indicated that it would provide the staff with a final analysis by March 31, 1988, as required by the staff's December 1987 code relief approval.
In discussions with the licensee, the staff was informed that the licensee would also request approval of a program to reduce steam generator tube degradation in Unit 1 by reducing the plant's operating temperature and pressure.
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The accident analysis for long-term containment pressure associated with the reduced temperature and pressure program would make the March 1988 analysis concerning long-term containment pressure invalid.
Therefore, to prevent reviewing an invalid analysis, the staff recommended that the licensee not submit the March 1988 analysis, and complete the final long-term containment pressure analysis with the new reduced temperature and pressure figures on an expedited schedule.
By letter dated April 15, 1988, the licensee requested extension of the interim code relief until the final analysis is completed.
The extension is needed because interim relief for Unit 1 will expire June 30, 1988.
The licensee indicated the analysis will be submitted to NRC for review in September
- 1988, and therefore requested extension of the present code relief until January 31, 1989.
EVALUATION The inservice testing requirements for these valves date from 1981.
The licensee has reviewed the test results and has determined that there were no failures in any of the subject Unit 1 valves.
The Unit 1 valves were tested during the Cycle 9-10 refueling outage, which ended in October 1987, with no failures.
The ASME Code,Section XI, allows testing a valve at cold shutdown, in lieu of quarterly testing, if the licensee can demonstrate that testing the valve during power operation is not practical and can result in damage of other plant equipment.
As indicated above, the licensee requested relief from quarterly testing of IM0-330,
-331, -340 and -350 since the test configuration and time required for testing these valves may place the plant in a condition that may be inconsistent with the plant design basis and associated Technical Specification requirements.
In order to perform the required test, part of one RHR train needs to be isolated.
By isolating one train, the licensee states that operable flow paths will be available to only two reactor coolant loops rather than four as required in the safety analysis.
Based on the previous staff evaluation of the licensee's original request for relief and additional discussion with the licensee, the staff has reconfirmed that testing of these valves in their present configuration would place the plant in an unanalyzed condition.
It is therefore prudent to grant an extension of the interim relief to allow the licensee additional time to complete the required evaluation of the unanalyzed condition.
CONCLUSION Based on the above discussion, the staff concludes that the interim relief be granted for Unit 1 so that the licensee can complete its required analysis.
By the surveillance date in March 1989, the licensee's analysis of overpressurization of containment and our evaluation should be complete and actions finalized for future testing schedules.
However, the licensee should complete and submit its analysis results for staff review in September 1988, to allow the staff sufficient time to complete its review.
Date:
Principal Contributor: J.
Stang
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