ML13308B531
| ML13308B531 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 05/05/1976 |
| From: | Fogarty D SOUTHERN CALIFORNIA EDISON CO. |
| To: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| IEB-76-05, IEB-76-5, NUDOCS 8103110158 | |
| Download: ML13308B531 (5) | |
Text
Southern California Edison Company P.
. BOX 800 2244 WALNUT GROVE AVENUE DAVID J. FOGARTY ROSEMEAD, CALIFORNIA 91770 TELEPHONE T
213-572-2796 May 5, 1976 U. S. Nuclear Regulatory Commission Region V Walnut Creek Plaza, Suite 202 1990 North California Boulevard Walnut Creek, California 94596 Docket No. 50-206 Attention:
Mr. R. H..Engelken Director
Dear Sir:
IE Bulletin No. 76-05 Westinghouse BFD Relay Failures Reference is made to your correspondence of April 5, 1976 forwarding the subject bulletin.
A review of our plant electrical schemes confirmed utilization of twelve BFD type relays in reactor protection circuits at this facility. Examination of the relays commenced in February, 1976 and because of plant operations was completed during our recent April, 1976 plant outage.
Relay dropout times were measured on all relays. The maximum dropout time recorded was 21 milliseconds.
Coil temperatures were found to average 168 degrees Fahrenheit for the varnished cloth coils (503C428621) and 178 degrees Fahrenheit for the molded outer coil form (1259C71G19). A review of plant battery records verifies equalizing charges were maintained for not more than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and did not exceed 139 volts DC.
Results obtained from relay tests provide reasonable assurance that BFD relays in service at this facility have not deteriorated.
It is.planned to selectively sample test BFD relays in the future until this potential problem is resolved. Additionally, measures will be taken to provide continued assurance that equalizing charges will not exceed 139 volts and 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> duration.
-2 Response pertaining to Dockets Nos. 50-361 and 50-362 will be provided under separate cover.
Sincerely, cc:
NRC Office of Inspection and Enforcement Division of Reactor Inspection Programs Washington, D. C.
20555
May 5, 1976 U. S. Nuclear Regulatory Commission Region V
.Walnust Creek Plaza, Suite 202 1990 North California Boulevard Walnut Creek, California 94596 Docket No. 50-206 Attention:
Mr. R. H. Engelken Director
Dear Sir:
IE Bulletin No. 76-05 Westinghouse BFD Relay Failures Reference is made to your correspondence of April 5, 1976 forwarding the subject bulletin.
A review of our plant electrical schemes confirmed utilization of twelve BFD type relays in reactor protection circuits at this
-facility.
Examination of the relays commenced in February, 1976 and because of plant operations was completed during our.recent April, 1976 plant outage.
Relay dropout times were measured on all relays.
The maximum dropout time recorded was 21 milliseconds..
Coil temperatures were found to average 168 degrees Fahrenheit for the varnished cloth coils (503C428621) and 178 degrees Fahrenheit for the molded outer coil form (1259C71G19).
A review of plant battery records verifies equalizing charges were maintained for not more than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and did not exceed 139 volts DC.
Results obtained from relay tests provide reasonable assurance that BFD relays in service at this facility have not deteriorated.
1t is planned to selectively sample test BFD relays in the future until this potential problem is resolved. Additionally, measures will be taken to provide continued assurance that equalizing charges will not exceed 139 volts and 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> duration.
31/9
-2 Response pertaining to Dockets Nos. 50-361 and 50-362 will be provided under separate cover.
Sincerely,
. RINAL SiGNED (D. J. Fogarty) cc:
NRC Office of Inspection and Enforcement Division of Reactor Inspection Programs Washington, D. C.
20555
-2 Response covering Dockets Nos. 50-361 and 50-362 will be provided under separate cover.
Sincerely, O~GIAL SINE (D. J. Fogarty) cc:
U.S.,Nuclear Requlatory Commission Office of Inspection and Enforcement Division of Reactor Inspection Programs Washington, D.C.
2 055