ML13317A550
| ML13317A550 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 03/18/1983 |
| From: | Krieger R Southern California Edison Co |
| To: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| REF-SSINS-6820 IEB-83-01, IEB-83-1, NUDOCS 8303220085 | |
| Download: ML13317A550 (2) | |
Text
Southern California Edison Company P.O. BOX 80&
2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 March 18, 1983 U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region V 1450 Maria Lane, Suite 210 Walnut Creek, California 94596-5368 Attention:
Mr. R. H. Engelken, Regional Administrator
Dear Sir:
Subject:
Docket No. 50-206 IE Bulletin No. 83-01:
Failure of Reactor Trip Breakers (Westinghouse DB-50) to Open on Automatic Trip Signal San Onofre Nuclear Generating Station Unit 1
Reference:
March 8, 1983 letter from R. Dietch, SCE, to R. H. Engelken, NRC, concerning same subject The reference provided you with the seven-day response requested by Action Item No. 4 of IE Bulletin No. 83-01.
This submittal consisted of a status report on Action Item Nos. 1, 2 and 3.
In response to Action Item No. 1, we informed you that you would be advised of the results of the scram breaker testing by March 18, 1983.
The results of this testing are discussed below.
Action Item No. 1 states:
"Perform surveillance test of undervoltage trip function independent of the shunt trip within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of receipt of this bulletin unless equivalent testing has been performed within 5 days. Those plants for which on-line testability is not provided may complete this item before resuming operation or if currently operating, at the next plant shutdown."
As discussed in the reference, San Onofre Unit 1 is currently shutdown with no immediate plans for resuming operation. In addition, on-line testability is not provided. Based on these considerations, we determined that San Onofre Unit 1 was exempt from performing the testing within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of receipt of the bulletin. A representative of the Region V staff was then informed of this decision and that the testing was scheduled for March 8, 1983.
The testing was actually performed on March 7, 1983.
In this testing, each of San Onofre Unit 1's two scram breakers were subjected to three simulated undervoltage events. In all cases, each scram breaker successfully performed the undervoltage trip function independent of the shunt trip. The testing results are'documented at San Onofre Unit 1.
8303220085 830318 PDR ADOCK 05000206 Q
?PDR
Mr. R.
March 18, 1983 Testing of the two reactor scram breakers was repeated on March 16, 1983 in the presence of an NRC representative. As in the testing above, the breakers were subjected to three undervoltage events.
In all cases, the breakers successfully operated. These results are also documented at San Onofre Unit 1.
The following discussion is provided to clarify our response to Sub-item b in the reference and to correct our statements concerning the type of lubricant used on the undervoltage trip attachment. The current San Onofre Unit 1 Type DB circuit breaker refueling interval preventive maintenance procedure specifies the use of dry graphite lubricant and not Molykote 321R.
Additionally, although this procedure does address cleaning, lubricating, and inspecting the breakers, the procedure does not do so in a manner consistent with the guidance contained in the recommended Westinghouse program. The procedure is presently deficient in the use of proper lubricant, the frequency at which breaker maintenance is performed, and the maintenance of the undervoltage trip attachment.
Before San Onofre Unit 1 is permitted to leave Mode 5, the deficiencies of the Type DB circuit breaker maintenance procedure will be corrected, the maintenance required by Action Item No. 2 of IE Bulletin No. 83-01 will be performed, and the breaker surveillance testing specified by Action Item No. 1 of IE Bulletin No. 83-01 will be repeated. The results of the breaker surveillance testing will be submitted to you within seven days of test completion. Until the actions listed in this paragraph are completed, the two reactor scram breakers will not be declared operable.
Please contact me if you have any questions or would like additional information on the reactor scram breakers at San Onofre Unit 1.
Subscribed on this /_P day of
, 1983.
Respectfully submitted, SOUTH ALIFORNIA EDISON COMPANY By:
R. W. Krieger Supervising Engine San Onofre Unit 1 Licensing Subscribed and sworn to before me this day of 17/P OFFICIAL SEAL AGNES CRABTREE NOTARY PUBLIC -
CALIFORNIA Notar Public in and for the County of ANIPAL OFFICEIN Los geles, State of California LOSANGELESCOUNTY My Commission Expires Aug. 27, 1986 My Commission Expires: d&.?77 79,/