ML20245A605
| ML20245A605 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 03/27/1987 |
| From: | Wegner M NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Lam P NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| Shared Package | |
| ML20245A607 | List: |
| References | |
| NUDOCS 8704270034 | |
| Download: ML20245A605 (1) | |
Text
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UNITED STATES g
NUCLEAR REGULATORY COMMISSION
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r WASHINGTON, D. C. 20666
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i MEMORANDUM FOR: Peter Lam, Chief 1
Reactor Systems Section 2 Reactor Operation Analysis Branch Office for Analysis and Evaluation of Operational Data FROM:
Mary S. Wegner, Reactor Systems Engineer Reactor Systems Section 2 Reactor Operations Analysis Branch Office for Analysis and Evaluation of Operational Data
SUBJECT:
TECHNICAL REVIEW REPORT: PRESSURIZER CODE SAFETY VALVE RELIABILITY The subject technical review report is enclosed for your consideration. The study was initiated as a result of the screening of a Diablo Canyon 1 licensee event report (LER 86-018). Our evaluation found that upon testing their pressurizer Code safety valves with the unit at hot standby, Diablo Canyon 1 personnel found their lift setpoints to be above their technical specifications (TS) limits. The test method was questioned and its proper use was determined.
The valves were correctly reset. A data search indicated that a total of 34 pressurizer Code safety valves at 17 plants had setpoint drift, leakage, misadjusted ring settings, or maintenance / installation problems since January 1, 1983. These problems could lead to inadvertent reactor scrams, overpressure-ization of the reactor coolant system (RCS), or degradation of the reactor coolant pressure boundary. These problems appear to be generic to all safety /
relief valves.
It is suggested that AEOD initiate a case study to determine the extent of the problems and to assess the adequacy of present efforts toward increasing safety valve reliability.
. vary S. We er, Reactor Systems Engineer Reactor Sy tems Section 2 Reactor Operations Analysis Branch Office for Analysis and Evaluation of Operational Data
Enclosure:
As stated cc w/ enclosure:
O-f T. Gwynn, OCM
- i. Gifford, GE s
L. Brinkman, CE W. Beaumont, W l
R. Borsum, B&W t
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