Headquarters Daily Report OCTOBER 21, 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 OCTOBER 21, 1996 Licensee/Facility: Notification: Duquesne Light Co. MR Number: 1-96-0095 Beaver Valley 2 Date: 10/21/96 Shippingport,Pennsylvania Dockets: 50-412 PWR/W-3-LP Subject: UNIT 2 CORE OFFLOAD TO REPAIR RHR PUMP SEALS Discussion: On October 13, 1996, operators observed that the Unit 2 "A" RHR pump seal was leaking approximately 1 gpm. The "B" RHR pump seal was also leaking, but at a much lower rate. The unit was in cold shutdown (mode 5) nearing completion of a planned refueling outage. RHR was in service while the unit was maintained in mode 5 pending completion of approximately 250 J-series relay replacements. The RHR system is designed to provide shutdown cooling and is designated as safe shutdown equipment. RHR has no ECCS function and is isolated during normal power operation. Increasing leakage observed from the RHR pump seals and consultation with the RHR pump vendor (Westinghouse) led management to conclude that the seals should be replaced now instead of awaiting the next planned refueling outage. The seals were nearing the end of their service life, but had not been previously identified for replacement in the planned outage work scope. Management determined that the heavy load lift path for removal of the RHR motor would pass close to the unisolable incore thimble tubes and constitute an unreviewed safety question while fuel was in the core. Duquesne Light Company (DLC) performed an indepth issue assessment and on October 18, decided to offload all fuel from the reactor vessel (RV) to establish appropriate plant conditions to safely replace the pump seal and lower bearing on both RHR pumps. The RHR pump seal repairs are likely to extend the planned outage duration by an additional 25 days. Core offload is expected to begin on October 25 and the adjusted on-line projection date following the outage is November 17. Regional Action: The resident inspectors have closely monitored the licensee's RHR pump seal leakage assessment and will continue to monitor outage activities. Contact: Pete Eselgroth (610)337-5234 David Kern (412)643-2000 _ REGION IV MORNING REPORT PAGE 2 OCTOBER 21, 1996 Licensee/Facility: Notification: Texas Utilities Electric Co. MR Number: 4-96-0108 Comanche Peak 2 Date: 10/21/96 Glen Rose,Texas Senior Resident Inspector Dockets: 50-446 PWR/W-4-LP Subject: UNIT 2 REACTOR TRIP DUE TO LOSS OF REACTOR COOLANT PUMP 2-03 Reportable Event Number: 31176 Discussion: At 3:06 a.m. on October 18, a Unit 2 reactor trip occurred when electrical Bus 2A3 tripped and deenergized Reactor Coolant Pump 2-03. All systems functioned properly in response to the trip. Initial investigation by the licensee indicated that the Bus 2A3 supply breaker tripped due to an activated 86 lockout relay for the bus. The breaker to Service Air Compressor 2-01 was found to be tripped, with its supply breaker indicating a phase-to-ground fault. Service Air Compressor 2-01 was powered from BUS 2A3. The licensee's alarm printer indicated that the service air compressor breaker tripped after the reactor tripped. Plant personnel also reported a flash and popping noise at the time of the trip in the vicinity of the Unit 2 unit transformer. The Service Air Compressor motor was found to have one open phase. Licensee testing of the relays and breakers associated with the Service Air Compressor and Bus 2A3 could not duplicate the condition experienced during the trip. Their investigation concluded that the most probable cause for the bus trip was a slow opening of the Service Air Compressor supply breaker, which allowed the overcurrent condition to be sensed by the Bus 2A3 lockout relay. Subsequent inspection and testing of the Unit 2 unit transformer by Glen Rose Transmission personnel identified no adverse conditions. Bus 2A3 was restored to service and RCP 2-03 was restarted. The reactor was taken critical at 1:47 a.m. on October 19 and reached full power at 1 p.m. on October 20. Regional Action: The resident inspectors responded to the site following notification of the trip and monitored the licensee's activities. Contact: A. T. Gody, Jr. (817)897-1500 _