ML19262B589
| ML19262B589 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 12/18/1979 |
| From: | Crews E SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | |
| References | |
| NUDOCS 7912280610 | |
| Download: ML19262B589 (2) | |
Text
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SOUTH CAROLINA EttcTRic a GAS COMPANY n o n.c......
COLUMBIA, SOUTH CAROLINA 29218 v,... f,N[.EsN.*c'uc.,,..
December 18, 1979 c
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Mr. James P. O'Reilly, Director Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Region II, Suite 3100 101 Marietta Street, N. W.
Atlanta, Georgia 30303
Subject:
Virgil C. Summer Nuclear Station Reportable Significant Deficiency Docket No. 50/395 Nuclear Engineering File - 3.1051
Dear Mr. O'Reilly:
On December 17, 1979 Mr. Ronald Clary of South Carolina Electric and Gas Company (SCE&G) reported an item as a reportable significant deficiency under 10CFR 50.55(e) to Mr. Jack Skolds, resident NRC Inspector at the Virgil C. Summer Nuclear Station.
It involves a problem discovered at the plant with eighteen automatic dampers in the ventilation system which are associated with twelve safety related fans.
Supply and discharge dampers must be open for the fans to operate. A control arm and lever arrangement in conjunction with limit switches is used to provide the necessary signals.
The design by the manufacturer (Bahnson, Industrial Air Quality Division, Box 10458, Winston Salem, N. C. 27108) did not account for the hardness of a shaft and too hard a material was used. Under operating conditions setscrews holding the control arm which contacts the limit switches are coming loose from the shaft. Therefore, improper damper position signals may be sent to the fan controller and the fans may not operate when required.
Ventilation systems which are affected are the fuel handling building charcoal exhaust system, control building emergency system, battery room exhaust system, diesel generator cooling system, and the service water pumnhouse cooling system.
Failure of fans to operate in these systems could possibly lead to excessive radiation exposures or affect the ability of the plant to safely shutdown.
There is, however, indication in the control room of fan operation, but corrective action by plant operators may not be taken in time to avoid the problems discussed above.
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Mr. James P. O'Reilly, Director Office of Inspection & Enforcement December 18, 1979 Page Two Corrective action being taken is to tack weld the collar holding the control arm onto the shaft. Limit switch settings will be rechecked during the ongoing startup test period.
The matter of possible 10CFR21 considerations was discussed with Bahnson. Any action regarding this will be reported by Bahnson, if re-quired. Under the SCESG program this item is reported as a significant deficiency per 10CFR50.55(e). Since repairs are in progress. SCE&G con-siders this 30 day report the final report.
If you have any questions, please let us know.
Very t ruly yours,
. H.
ews, Jr.
REC:EHC:jw cc: Office of Inspection & Enforcement Washington, D. C.
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