ML20027C004
| ML20027C004 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 12/18/1980 |
| From: | Chiramal M NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | |
| Shared Package | |
| ML20027C005 | List: |
| References | |
| TASK-AE, TASK-E018, TASK-E18 AEOD-E018, AEOD-E18, NUDOCS 8210120155 | |
| Download: ML20027C004 (1) | |
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UNITED STATES g
NUCLEAR REGULATORY COMMISSION AEOD/E018 3
l WASHINGTON, D. C. 20555 k
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This is an internal, pre-decisional document not necessarily representing a position of AE0D or NRC.
DEC 181980 NOTE T0: File FROM:
Matthew Chiramal Office for Analysis and Evaluation of Operational Data
SUBJECT:
P0TENTIAL FAILURE OF BWR BACKUP SCRAM (MODE SWITCH IN SHUTDOWN)
CAPABILITY
REFERENCE:
PILGRIM NUCLEAR POWER STATION LER 80-038/0lT-0 DATED 8/29/80 Based on a quick review of the referenced LER, the resident inspectors report on the LER, and typical BWR Reactor Protection Systems drawings, it was con-cluded that in certain BWR RPS system designs there exists the potential for the Mode Selector Switch (MSS) to fail in fully performing it designed functions.
Specifically, one of the functions the MSS is designed to perform when the
" shutdown" position is selected, is to cause a reactor scram. Under the circumstance that happened at Pilgrim Nuclear Power Plant, this scram function of the MSS may not occur.
(See attached LER and typical BWR RPS drawing).
On December 12, 1980, meetings were held with NRR and IE and it was proposed that NRR would initiate a draft information notice for IE to issue.
(See attached draft information notice dated December 15, 1980, from G. C. Lainas,
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DL/NRR to E. L. Jordan, IE). We had also contacted GE personnel and was informed that a ServiceInformation Letter (SIL) on this potential problem and the design modification to correct it will be issued shortly.
Based on an engineering evaluation I consider the actions being taken by NRR, IE and GE, to be adequate for the present.
Matthew Chiramal Office for Analysis and Evaluation of Operational Data cc:
C. Michelson J. Heltemes S. Rubin G. Lanik
Enclosures:
As Stated I
8210120155 801218 PDR ADOCK 05000293 S
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