Headquarters Daily Report MAY 10, 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 MAY 10, 1996 Licensee/Facility: Notification: Peco Energy Company. MR Number: 1-96-0048 Limerick 2 Date: 05/10/96 Philadelphia,Pennsylvania SRI PC Dockets: 50-353 BWR/GE-4 Subject: EMERGENCY DIESEL GENERATOR CRANKCASE OVERPRESSURE CONDITION Discussion: On May 7, 1996, during the performance of a slow start surveillance test, the D22 emergency diesel generator (EDG) was shut down prematurely due to a crankcase overpressure condition. Within a few minutes after fully loading the engine, equipment operators observed a rapid increase in engine crankcase pressure. Control room operators expeditiously unloaded and secured the engine and declared it inoperable. Subsequently, all seven remaining EDGs were started and loaded for one hour to verify their operability. Limerick has eight Colt Fairbanks Morse 12 cylinder, 24 opposed piston engines (four per unit). Inspections of the D22 EDG by PECO Energy have revealed a failed piston ring and a cracked second ring on the No. 5 lower piston. Additionally, a minor jacket water leak was found on the No. 12 cylinder liner. The No. 5 and No. 12 cylinder liners and the No. 5 lower piston were replaced. Exhaust gas blow-by past the deficient piston rings may have caused the high crankcase pressure condition; however, PECO Energy has not yet concluded that this is the cause of the event. Root cause analysis efforts are continuing. Further inspections of the D22 EDG are planned, based on information from three previous crankcase overpressure events at Limerick during the past two years. Two of these occurred in November 1995, and the third was in September 1994. PECO Energy concluded that the causes of the previous events were most likely related to loose or degraded flexmaster fittings on vacuum piping from the crankcase to the exhaust ejector housing. Regional Action: The resident inspectors are following PECO Energy's troubleshooting and repair efforts. Contact: WALTER PASCIAK (610)337-5258 NEIL PERRY (610)327-1344 _ REGION II MORNING REPORT PAGE 2 MAY 10, 1996 Licensee/Facility: Notification: South Carolina Electric & Gas Co. MR Number: 2-96-0043 Summer 1 Date: 05/10/96 Jenkinsville,South Carolina Dockets: 50-395 PWR/W-3-LP Subject: INADVERTENT TRANSFER OF REFUELING WATER STORAGE TANK (RWST) INVENTORY TO CONTAINMENT SUMP Discussion: The unit is currently in an outage in MODE 5. Fuel has been reloaded into the reactor vessel and the reactor head has been installed. On May 9, 1996, at approximately 5:10 pm, the licensee inadvertently created a direct flow path from the RWST to the "B" containment recirculation sump. It was estimated that approximately 6000 gallons of RWST water flowed to the sump prior to being secured by a control room supervisor. Operators were performing integrated safeguards testing on Train "B" when the event occurred. The transfer of water resulted when valves in the Residual Heat Removal (RHR) and Containment Spray (CS) lines from the "B" RHR and CS sump were energized while a locked-in safety injection signal existed. This caused the valves to open creating a direct flow path from the RWST to the sump. Procedural steps would have prevented this transfer. However, the controlling procedure was issued to operations from Document Control with a page missing. No inventory was lost from the Reactor Coolant System. Train "A" RHR cooling was maintained throughout the event. Regional Action: Resident Inspector Followup. Contact: A. Belisle (404)331-4196 _