Headquarters Daily Report SEPTEMBER 11, 1995 *************************************************************************** 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 SEP. 11, 1995 Licensee/Facility: Notification: Baltimore Gas & Elec Co. MR Number: 1-95-0116 Calvert Cliffs 1 2 Date: 09/08/95 Lusby,Maryland ENS Call Dockets: 50-317,50-318 PWR/CE,PWR/CE Subject: Fitness-for-Duty Discussion: On September 8, 1995, Baltimore Gas and Electric made an ENS call in accordance with 10 CFR 26.73 to report that a security supervisor had tested positive on a random Fitness-for-Duty (FFD) test. The supervisor's site access had been revoked and all locks, keys and passwords to which he had access are being changed. The supervisor stated he is going to appeal the results of the FFD test. The appeal process consists of another analysis of a split portion of the original sample by the same or a different Health and Human Services laboratory. Test results of the appeal analysis are expected to take about a week. Region I will continue to monitor this event until the appeal process is completed. Contact: Gregory C. Smith (610)337-5263 _ REGION IV MORNING REPORT PAGE 2 SEPTEMBER 11, 1995 Licensee/Facility: Notification: Pacific Gas & Electric Co. MR Number: 4-95-0111 Diablo Canyon 1 Date: 09/11/95 Avila Beach,California Dockets: 50-275 PWR/W-4-LP Subject: UPDATE OF REACTOR TRIP Reportable Event Number: 29300 Discussion: On Wednesday, September 6, 1995, at 3:55 p.m. (PDT), Diablo Canyon Unit 1 experienced a reactor trip resulting from a turbine trip caused by a loss of auto-stop oil pressure. During the investigation of the low auto-stop oil pressure, a solenoid valve (SV-171) was found stuck open. Upon disassembly of Valve SV-171 (ASCO Model 8223A10), the pilot valve urethane seat was noted to have degraded, allowing the solenoid valve to open. In 1989, ASCO changed the seat material from teflon to urethane and has since noted failures of the valve seat in applications where it comes in contact with water and lube oil. In February 1994, ASCO began installing teflon seats for solenoid valves used in this application. After the Unit 1 reactor trip, the licensee replaced the solenoid valve with one containing a urethane seat and considered it acceptable based on there being only 3 weeks remaining until the start of the unit's refueling outage on September 30, 1995. During the reactor trip, Emergency Diesel Generator (EDG) 1-1 autostarted. This was attributed to the slow decrease in 4 kV Bus H voltage due to the relatively light bus loading (previously reported as Bus F). In the trip of September 6, 1995, the transfer to startup power was initiated 30 seconds after the reactor trip when the auxiliary transformer feeder breaker opened. On a slow bus transfer, the startup feeder breaker supplying the respective 4 kV bus closes after bus voltage decreases to approximately 25 percent of rated voltage. The first level undervoltage relay protection (inverse time) for Bus H actuated when bus voltage decreased to below 69 percent of rated voltage. Since the time delay for the first level undervoltage relay (for EDG start) elapsed prior to 4 kV Bus H voltage decreasing to 25 percent, the first level undervoltage relay actuated, starting EDG 1-1. Approximately 1.5 seconds following the auxiliary transformer feeder breaker opening, Bus H voltage decreased to less than 25 percent of rated voltage, at which point the startup transformer feeder breaker closed. The voltage of Bus H was restored prior to EDG 1-1 reaching rated speed and voltage. This occurred during previous reactor trips during a slow bus transfer to start up power and is considered not to have a safety impact. After evaluation of the above circumstances and resolution of other less significant issues, the licensee restarted the plant and achieved Mode 2 on September 8, 1995. It was noted that Indian Point 2 may have experienced a similar failure of an ASCO solenoid valve which caused a unit trip in January 1995. REGION IV MORNING REPORT PAGE 3 SEPTEMBER 11, 1995 MR Number: 4-95-0111 (cont.) Regional Action: REGIONAL ACTION: The Senior Resident and Resident Inspectors were onsite at the time of the trip. The inspectors monitored the licensee's root cause evaluation and actions for plant restart. Contact: Howard Wong (510)975-0296 M. Tschiltz (805)595-2354 _