ML20211P897
| ML20211P897 | |
| Person / Time | |
|---|---|
| Issue date: | 07/14/1986 |
| From: | Leeds E NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Rubin S NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| Shared Package | |
| ML20211P894 | List: |
| References | |
| REF-GTECI-A-01, REF-GTECI-PI, TASK-A-01, TASK-A-1, TASK-OR AEOD-E608, NUDOCS 8607230412 | |
| Download: ML20211P897 (2) | |
Text
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W July 14, 1986 MEMORANDUM FOR: Stuart D. Rubin, Chief Reactor Operations Analysis Branch Office for Analysis and Evaluation AE0D/E608 of Operational Data FROM: Eric J. Leeds, Reactor Systems Engineer Reactor Systems Section 1 Reactor Operations Analysis Branch Office for Analysis and Evaluation of Operational Data
SUBJECT:
RE-EXAMINATION OF WATER HAMMER OCCURRENCES The enclosed engineering evaluation report is forwarded for your information and consideration. The study found that the underlying causes and general nature of the water haniner events which have occurred over the past five years do not appear to indicate any new generic concern not already identified and examined by the staff. Check valves were involved in only 2 of the 40 water hammer events evaluated. Furthermore, check valves were found to have been specifically cited as contributing to only five of the almost 200 water hammer events evaluated since 1969. Therefore, the study concludes that check valve leakage or failure is not a significant common generic cause of water hammer.
The study also found that the occurrence of steam generator water hammer (SGWH) events has declined substantially during.the past five years as predicted by the staff in the resolution of USI A-1. This appears to be the result of the implementation of modifications described in Branch Technical Position (BTP)
ASB 10.2 at many domestic pressurized water reactors (PWRs). However, three of the four SGWH events reported since the resolution of USI A-1 have occurred at PWRs which had not implemented the J-tube modification described in BTP ASB 10.2.
Presently,13 operating PWRs apparently have not yet modified the bottom dis-charge steam generator feedrings. This study concludes that implementation of the J-tube modification at these plants could aid in preventing SGWH events in the future.
As a result of the water hammer occurrence at San Onofre Unit 1 on November 21, 1985, the Office of Nuclear Reactor Regulation is conducting a review of water hammer occurrences reported since 1981. This review is being performed 8607230412 860714 PDR ORG NEXD PDR
' f Stuart D. Rubin in an effort to assess the need to reopen USI A-1. It is suggested that NRR use the information, analysis and evaluation contained in this study to support their assessment of this issue.
/4 Eric J. Leeds, Reactor Systems Engineer Reactor Systems Section 1 Reactor Operations Analysis Branch Office for Analysis and Evaluation of Operational Data
Enclosure:
As Stated DISTRIBUTION
,POR' ROAB SF AE0D SF ROAB CF Eleeds SRubin KBlack WLanning FHebdon CHeltemes
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OFC : ROAB ,qge:rC:ROAB : DD:AEOD : : : :
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NAME : Eleeds:as : SDRubi
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DATE : 6/.J7/86 : b/27/86 : 7 / 9 /86 : : : :
OFFICIAL RECORD COPY
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