ML16288A509
| ML16288A509 | |
| Person / Time | |
|---|---|
| Issue date: | 11/20/1989 |
| From: | Banks M, Remick F Advisory Committee on Reactor Safeguards |
| To: | Carr K NRC/Chairman |
| References | |
| D891120 | |
| Download: ML16288A509 (12) | |
Text
D891120 The Honorable Kenneth M. Carr Chairman U.S. Nuclear Regulatory Commission Washington, D.C. 20555
Dear Chairman Carr:
SUBJECT:
PROPOSED RESOLUTION OF GENERIC ISSUE-87 (GI-87), "HPCI STEAM LINE BREAK WITHOUT ISOLATION" During the 355th meeting of the Advisory Committee on Reactor Safe-guards, November 16-18, 1989, we discussed the NRC staff's proposed resolution of GI-87. This subject was also considered during our 354th meeting on October 5-6, 1989. Our Subcommittee on Mechanical Components met with members of the NRC staff on October 3, 1989 to discuss this matter. We also had the benefit of the document referenced.
In spite of its title, the scope of GI-87 includes all safety-related valves that may be required to close against high differential pressures and/or high flows such as experienced during a large downstream pipe break. Possible deficiencies in the performance of such valves have been recognized recently as the result of operating experience and of tests and have been addressed by the staff in Generic Letter 89-10, "Safety-Related Motor-Operated Valve Testing and Surveillance." This generic letter requires each licensee to undertake a program to identify safety-related valves that may not perform adequately under design-basis conditions. Unfortunately, as pointed out in our May 9, 1989 report related to Generic Letter 89-10, the design basis for the HPCI steam line and other valves in some plants may not specify the type of heavy duty that is of concern. This means simply that the heavy duty loads for these valves do not have to be considered in the program required by Generic Letter 89-10, and the deficiencies addressed by GI-87 will not be remedied.
Unless Generic Letter 89-10 is amended to require updating or revision of the design basis for valves of this type, we do not consider the requirements of Generic Letter 89-10 as a complete resolution of GI-87.
Sincerely, Forrest J. Remick Chairman
Reference:
Memorandum dated July 17, 1989 from R. Wayne Houston, Office of Nuclear Regulatory Research, NRC, for R. F. Fraley, ACRS,
Subject:
Resolution of Generic Issue-87 (GI-87), "HPCI Steam Line Break Without Isolation"
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