Headquarters Daily Report MARCH 06, 1996 *************************************************************************** REPORT NEGATIVE NO INPUT ATTACHED INPUT RECEIVED RECEIVED HEADQUARTERS û REGION I û REGION II û REGION III û REGION IV û PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION I MARCH 6, 1996 Licensee/Facility: Notification: Consolidated Edison Co. Of N.Y. MR Number: 1-96-0019 Indian Point 2 Date: 03/06/96 Buchanan,New York Dockets: 50-247 PWR/W-4-LP Subject: Unit Trip and Local/Remote Switch Internal Component Failures Discussion: At 6:06 a.m. on March 5, 1996, the Indian Point Unit 2 reactor automatically tripped from 100% power. The trip occurred as a result of an off-site electrical disturbance that caused the generator to trip which in turn caused the reactor to trip as designed. Con Edison investigation after the trip revealed that the electrical disturbance should not have caused the Indian Point output breakers on the ring bus to open. Troubleshooting and testing of these circuits is currently being performed to determine why the output breakers opened. All plant systems responded to the trip as designed except for the 23 motor driven auxiliary boiler feed pump (ABFP), one of three ABFPs, which did not automatically start as expected. Manual actuation from the control room was also unsuccessful. The licensee determined that the failure of the ABFP pump to start was caused by a defective local/remote switch located on a remote safe shutdown panel near the ABFPs. Even though the switch was in its normal "remote" position and indicated so on the control room panel, the failure of an internal part of the switch, called a starwheel, caused a contact in the ABFP start circuitry to remain open, thus preventing the pump from starting automatically or from the remote control switch in the control room. The switch was replaced and the ABFP was successfully retested and declared operable. Based on this switch failure, the licensee examined other safety systems in the plant that use Westinghouse W-2 switches for local/remote and other functions. During initial testing of 4 of the identified 29 switches, two additional switches failed. Con Edison identified a Westinghouse Technical Bulletin, NSD-TB-74-10 issued on 9/9/74, which alerted plants to reported switch failures that used the material "texin" for the starwheel portion of the switch. The texin starwheel component is a light tan to dark brown color and was adversely affected by elevated temperatures, humidity and aging. Con Edison, in response to the bulletin, had performed a review of all W-2 switches in 1975 and replaced all those that used the tan/brown texin material with an acceptable black nylon material. At that time, the 23 ABFP W-2 switch was noted to have a white starwheel, which was thought to be an acceptable nylon material. However, upon removal of the failed 23 ABFP starwheel, it was noted to be a tan/brown color. Con Edison did not know if this discoloration was from aging or an error during the original review. Based on this discrepancy, Con Edison is replacing all 29 white safety related W-2 switch starwheels with black nylon starwheels prior to restart. Regional Action: The residents are following Con Edison's resolution of the switch problems. REGION I MORNING REPORT PAGE 2 MARCH 6, 1996 MR Number: 1-96-0019 (cont.) Contact: Curtis Cowgill (610)337-5233 Robert Temps (914)739-9360 Barry Westreich (914)739-9360 _