ML20235N888

Comments on Proposed Resolution of Generic Issues 70, Power Operated Relief Valve & Block Valve Reliability, & 94, Addl Low-Temp Overpressure Protection for Lwrs

ML20235N888
Person / Time
Issue date:	02/16/1989
From:	Remick F Advisory Committee on Reactor Safeguards
To:	Zech L NRC COMMISSION (OCM)
References
REF-GTECI-070, REF-GTECI-094, REF-GTECI-NI, TASK-070, TASK-094, TASK-70, TASK-94, TASK-OR ACRS-R-1338, NUDOCS 8903020018
Download: ML20235N888 (2)

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UNITED STATES 8 o NUCLEAR REGULATORY COMMISSION 5

ADVISORY COMMITTEE ON REACTOR SAFEGUARDS -

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. WASHINGTON, D. C. 20555 February 16, 1989 The Honorable Lando W. Zech, Jr.

Chairman U.S. Nuclear Regulatory Commission Washington, D.C. 20555

SUBJECT:

PROPOSED RESOLUTION OF GENERIC ISSUES 70, " POWER OPERATED RELIEF VALVE AND BLOCK VALVE RELIABILITY," AND 94, " ADDITIONAL LOW-TEMPERATURE OVERPRESSURE PROTECTION FOR LWRs" During the 346th meeting of the Advisory Committee on Reactor Safe-guards, February 9-11, 1989, we reviewed the proposed consolidated resolution of Generic Issues 70 and 94, as described in the memorandum from E. Beckjord to E. Jordan, dated December 7, 1988. Our Subcommittee on Mechanical Components also considered this matter during a meeting on January 27, 1989. During these meetings, we had the benefit of dis-cussions with representatives of the Office of Nuclear Regulatory Research and the Office of Nuclear Reactor Regulation, as well as with NRC staff consultants.

As a result of our review, we concur in the proposed resolution of Generic Issues 70 and 94, provided the following clarifications are added to the Plant Technical Specification Action Statements in En-closures C-1, D-1, and E to the generic letter in the proposed reso-lution package.

1) When one or more block valves associated with power operated relief valves (PORVs) are closed because of excessive relief valve seat leakage, it should be required that electrical power be maintained to the block valves to ensure quick reopening capability from the control room. This requirement was discussed in the Staff's Regulatory Analysis (Section 5.2) but was not stated explicitly in the Modified Technical Specifications. We believe it should be.

2) In the Surveillance Requirements section, the staff should state that the reactor coolant system should be in hot shutdown rather than cold shutdown when performing an operability test on the block valves or PORVs. In the Regulatory Analysis the staff states that stroke testing of these valves should be performed only at cold During our discussions with staff members, they agreed l' shutdown.

I that hot shutdown is the correct requirement.

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L______________.___ . _ . _ . _ _ . _ . . _ _ _ _ _ . _ _ _ _ _ _

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The Honorable Lando W. Zech, Jr. February 16, 1989

3) The _ Surveillance Requirements section should also include the solenoid air control valves and check valves on associated air accumulators. The inservice testing requirement stated in the Staff. Regulatory Analysis does include valves in PORV control systems. We believe that this statement should be modified to clearly specify the solenoid valves and the accumulator check valves in PORY control systems.

Additional comments by ACRS Members William Kerr, Harold W. Lewis and Paul G. Shewmon are presented below.

Sincerely, I

Forrest J. Remick Chairman Additional Comments by ACRS Member William Kerr Although intuitively I believe that improving the performance of power operated relief valves would decrease risk of reactor power plant operation, I do not believe the Staff's Regulatory Analysis demonstrated that this would occur. Nor do I believe it showed that what is proposed would improve the performance of relief valves.

Additional Comments by ACRS Members Harold W. Lewis and Paul G. Shewmon We were told by the staff that studies show that these valves pose an insignificant risk, but that, for other reasons, that were not pre-sented, they disagree with the analysis. That makes this an example of regulation for the sake of regulation with little impact on safety. As such, it is a bad example. We think that they have done no harm, but tnat is an inappropriate standard for the resolution of generic issues.

Reference:

Memorandum, with enclosures, dated December 7, 1988 from Eric S. Beck-jord, Director, Office of Nuclear Regulatory Research, NRC, to Edward L.

Jordan, Chairman, Committee to Review Generic Requirements, NRC,

Subject:

Request for CRGR Review of Proposed Resolutions of Generic Issue 70, " Power Operated Relief Valve and Block Valve Reliability" and Generic Issue 94, "Additioral Low-Temperature Overpressure Protection for Light Water Reactors" 1

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