ML19291B917
| ML19291B917 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 12/03/1979 |
| From: | Crews E SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | |
| References | |
| 3.1051, NUDOCS 7912140360 | |
| Download: ML19291B917 (2) | |
Text
I SOUTH CAROLINA ELECTRIC a gas COMPANY
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COLUMeA,Souf M CAROLINA 29218 E, H. Ca t w s, J n.
eca Passenant a=e Geowe Esscums
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December 3, 1979 Mr. James P. O'Reilly, Director U. S. Nuclear Regulatory Commission 101 Marietta Street, N. W.
Atlanta, Georgia 30303 Subiect:
V. C. Summer Nuclear Station Reportable Significant Deficiency -
Undetectable Failure in Engineered Safety Features Actuation System Nuclear Eng. File - 3.1051
Dear Mr. O'Reilly:
On November 7,1979 Mr. Jack Skolds and Mr. Tom Burdette of the NRC were notified by our Mr. R. B. Clary that Westinghouse had informed the NRC of an item considered to be reportable under 10CFR50.55(e). The item involved an undetectable failure in the Engineered Safety Features Actuation System.
A failure analysis, which assumed a failure of the affected circuit in both of the redundant protection trains (as required by IE2E 379 for un-detectable failures), showed that the Engineered Safety Features Actuation System's ability to automatically initiate Safety Iniection (SI) could be lost under certain conditions.
Currently, plant tests do not provide for checking the operation of the P-4 contacts or the interconnecting wiring. Therefore, a cotential failure of the P-4 contacts or in the associated wiring, would be undetectable.
This would result in either a prevention of the normal mode of resetting and blocking SI and alteration of the sequence of switchover operations from iniection to recirculation phase; or following a previous initiation if SI and manual reset and block, the block of SI could remain following the re-set of the reactor trip breakers and when the plant was returned to power.
Under SCE&G program requirements this item is reported to the NRC as a reportable significant deficiency under 10CFR50.55 (e).
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7013140380
I Mr. James P. O'Reilly, Director U. S. Nuclear Regulatory Commission December 3,1979 Page Two Corrective action involves revising appropriate plant procedures to require verification of the P-4 contact status following automatic reactor trip or any condition reauiring opening of the reactor trip breakers. Veri-fication tests will also be required following reclosure of the reactor trip breakers and prior to rod withdrawal. SCE&G Nuclear Operations has been ad-visedtomaketheseprocedurecpnges.
Based on this status. SC G considers this report a final report on this item.
ery tr y yours, t
Jr.
EllC:RBC:jw cc: Office of Inspection & Enforcement Washington, D. C.
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