Headquarters Daily Report NOVEMBER 16, 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 II NOV. 16, 1995 Licensee/Facility: Notification: Virginia Power Co. MR Number: 2-95-0097 Surry 2 Date: 11/16/95 Surry,Virginia Dockets: 50-281 PWR/W-3-LP Subject: UNIT 2, A STEAM GENERATOR HEAD DRAIN LINE LEAK Discussion: On November 15, 1995, Surry Unit 2 was shutdown but pressurized to 300 psig in preparation for restart following a reactor trip on November 7. During a walkdown of equipment inside containment, personnel observed water on the floor under the A steam generator. A several-drops-per-second reactor coolant leak was discovered originating at a non-isolable weld where the 3/8 inch drain line is attached to the bottom of the steam generator. Inspection of the other Unit 2 steam generator drain lines revealed no leaks. The reactor coolant system was depressurized. The A loop was isolated using loop stop valves and was drained. The drain line has been cut and will be plugged today. After the removed section is examined to determine the failure mechanism, a determination will be made whether or not similar modifications are necessary for the B and C steam generators prior to unit restart. If no additional repairs are warranted, the A loop will be refilled and preparations for restart will resume today. A visual inspection in Unit 1 revealed no evidence of steam generator drain line leaks. Unit 1 remains at 100 percent power. Regional Action: Routine followup. Contact: George Belisle (404)331-4196 _ REGION IV MORNING REPORT PAGE 2 NOVEMBER 16, 1995 Licensee/Facility: Notification: Houston Lighting & Power Co. MR Number: 4-95-0142 South Texas 2 Date: 11/15/95 Wadsworth,Texas Resident Ispectors Dockets: 50-499 PWR/W-4-LP Subject: TURBINE TRIP AND REACTOR TRIP Reportable Event Number: 29600 Discussion: On November 15, 1995, at approximately 12:32 a.m. (CST), the control room operators received indication of a problem with the main generator exciter. The control room operators observed an increase in voltage and current in the exciter. Operators were then dispatched to the exciter to perform troubleshooting activities. The licensee discovered that several fuses and diodes in the exciter had blown. At 6:32 a.m. the operators noted that the voltage meter for the exciter had pegged high. At that time the operators began reducing reactor power. At 7:02 a.m. the exciter field breaker opened, causing an automatic turbine trip and reactor trip from 90 percent reactor power. All control rods inserted completely. Following the reactor trip, the unit received an automatic main feedwater isolation and subsequent start of the auxiliary feedwater system due to low steam generator level. This was expected, and all systems functioned as required. The unit is currently in Mode 3 (Hot Standby) and stable. The resident inspector was in the control room at the time of the reactor trip and is following the licensee's investigation. A Westinghouse generators/exciter technical expert was contacted and arrived on site on November 15. Currently, no major problems have been identified that would have caused the failure of the fuses and diodes. The resident inspectors have been reviewing a preventive maintenance surveillance that was performed on the exciter just prior to the unit startup on November 2, 1995, and have identified several resistance readings that had not met the acceptance requirements set forth in the surveillance procedure. The licensee and the residents are continuing to investigate this concern. The licensee is currently trying to resolve any problems associated with the exciter and also is working forced outage items. If no other problems or concerns are identified, the licensee plans on returning the unit to service after replacement of the fuses and diodes, which could take place later today (November 16). Regional Action: The resident inspectors are continuing to follow the licensee's activities and are reviewing the surveillance procedure to determine whether there are any generic concerns relative to safety-related equipment surveillances that may not have been adequately reviewed prior to the startup of Unit 2 on November 2. Contact: John L. Pellet (817)860-8183 Ronald A. Kopriva (817)860-8104 _