Headquarters Daily Report DECEMBER 06, 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 DEC. 06, 1995 Licensee/Facility: Notification: Public Service Electric & Gas Co. MR Number: 1-95-0150 Hope Creek 1 Date: 12/05/95 Hancocks Bridge,New Jersey Dockets: 50-354 BWR/GE-4 Subject: SAFETY AUXILIARY COOLING SYSTEM (SACS) INOPERABLE REPORTABLE EVENT NUMBER: 29666 Discussion: On December 4, 1995, with the Unit in a refueling condition, the licensee determined that the operating SACS loop (one of two loops) had operating temperatures below the minimum design temperature of 65 degrees F as specified in UFSAR Table 9.2-3. The SACS system is a closed-loop, cooling water system that rejects heat from safety related systems in the station, such as, decay heat removal, emergency diesel generators and both normal and emergency ventilation, to the service water (SWS) system (ultimate heat sink) through two redundant subsystems, each with a set of two SACS-to-SWS heat exchangers. The stress calculations for the SACS system were based on a minimum temperature of 65 degrees F. Actual operating temperatures range from about 43 to 61 degrees for various components and associated pipe. As a result, the licensee declared the SACS system inoperable; and, since it is a support system to other required systems, have also declared these systems, such as the diesels and HVAC, inoperable. The applicable compensatory actions required by the Technical Specifications, such as suspending core alterations and evolutions that could drain the vessel, have been implemented. The licensee is currently pursuing means to ensure that SACS operating temperatures are maintained above 65 degrees F. Preliminary information shows that SACS may have been operated in this manner repeatedly in the past whenever SWS temperatures were low during wintertime, whether or not the station was operating or shutdown. In the interim, even though SACS is inoperable, the system is being maintained in service to ensure the availability of the supported systems. Regional Action: Routine resident follow up. Contact: Robert Summers (610)337-5189 Larry Nicholson (610)337-5128 _ REGION I MORNING REPORT PAGE 2 DECEMBER 6, 1995 Licensee/Facility: Notification: Peco Energy Company. MR Number: 1-95-0149 Limerick 1 Date: 12/05/95 Philadelphia,Pennsylvania SRI PC Dockets: 50-352 BWR/GE-4 Subject: EMERGENCY DIESEL GENERATOR CRANKCASE OVERPRESSURIZATION Discussion: On November 29, 1995, with Unit 1 at 100 percent power, a monthly operability test was performed on the D14 emergency diesel generator (EDG) following completion of a 10 year fuel oil storage tank cleaning. This monthly test included a fast start (10 second)/fast loading (200 seconds) sequence required by technical specifications once per 184 days. The engine was loaded to 2700 KW, 100 percent of rated, and ran at that load for 20 minutes prior to being raised to 3000 KW, 105 percent of rated, for post maintenance testing following an adjustment of the engine governor linkage. Approximately three minutes after reaching the 3000 KW load, a rapid and sustained increase in engine crankcase pressure was observed by the equipment operator in the engine room. The operator noted that all the water was expelled from the crankcase vacuum manometer, followed by lubricating oil spraying past the oil seals at both ends of the engine. The operator immediately contacted the control room and requested that the engine be unloaded and shut down. The engine was removed from service 90 seconds later. The licensee contacted the vendor and a representative was sent to the site. On December 1, 1995, following the cleaning and inspection of the engine a diagnostic test run was performed on D14 with the engine loaded to 3000 KW. The results of the diagnostic test indicated that proper cylinder compression was present on all cylinders, and the engine ran with no problems identified. The diagnostic run was followed by a two hour full load operability test run, including a fast start/fast loading sequence. The operability test was completed without incident and the diesel was declared operable. The licensee is continuing to review the diagnostic and operability test results to determine the cause of the initial crankcase overpressure condition. Regional Action: The resident inspectors will continue to review the licensee's current investigation. The inspectors will review the formal root cause analysis and resulting recommendations when the licensee has completed its investigation. Contact: WALT PASCIAK (610)337-5258 NEIL PERRY (610)327-1344 _ REGION I MORNING REPORT PAGE 3 DECEMBER 6, 1995 Licensee/Facility: Notification: Pennsylvania Power & Light Co. MR Number: 1-95-0148 Susquehanna 1 2 Date: 12/05/95 Allentown,Pennsylvania RI PC Dockets: 50-387,50-388 BWR/GE-4,BWR/GE-4 Subject: PRESSURE LOCKING OF HPCI AND RCIC INJECTION VALVES Discussion: On November 30, 1995, with Unit 1 in cold shutdown, the licensee concluded that deformation of pressure retaining components in the HPCI injection valve was caused by thermal expansion of water entrapped in the valve's bonnet cavity. The HPCI injection valve is a 14 inch Anchor Darling pressure seal, flex wedge gate valve. The HPCI system injects through the main feedwater system and the injection valve is located four feet from the tie in with the feedwater line. Increasing feedwater temperature during past plant startups is thought to have caused pressure locking of the injection valve rendering HPCI inoperable. The licensee believes that the high bonnet pressure subsequently relieved itself (through the packing, bonnet seal, or disk seats) and therefore the duration of this phenomena is not known. The location of the HPCI valve and it's direct interface with feedwater are considered significant contributors to this scenario. In addition, the HPCI injection valve and the four feet of piping connecting it to the feedwater line are insulated. Investigations are in progress to determine why the HPCI and RCIC injection valves were overlooked during a 1992 pressure locking evaluation. The LPCI and Core Spray injection valves were modified as a result of this study. Unit 2 is currently operating at 100% power. The HPCI and RCIC injection valves were stroked on 11/30. Acceptable IST stroke times were recorded and MOV motor current traces did not indicate excessive actuator loading. The valves are considered operable and no pressure buildup is expected during steady state power operation since feedwater temperature will remain essentially constant. Based on questions from the NRC Resident Inspectors, the licensee has investigated the potential for power changes and offnormal events, such as loss of feedwater heating, to cause pressure locking of the HPCI or RCIC injection valves. The licensee's preliminary analysis has found that small temperature changes inside the valve's bonnet could potentially induce pressure locking; however, the temperature of the entrapped water is dependent on conductive heat transfer from the feedwater line and the time lag of feedwater temperature changes in response to other plant parameters. As an interim measure the licensee has instituted administrative controls for activities that would potentially affect feedwater temperature. The licensee's review of FSAR analyzed transients has not identified other scenarios that would cause pressure locking. REGION I MORNING REPORT PAGE 4 DECEMBER 6, 1995 MR Number: 1-95-0148 (cont.) Regional Action: The resident inspectors will continued to monitor the licensee's response to this event and Region I, Division of Reactor Safety, is providing assistance in reviewing repair and inspection records for the Unit 1 HPCI injection valve. Contact: WALT PASCIAK (610)337-5258 _ REGION III MORNING REPORT PAGE 4 DECEMBER 6, 1995 Licensee/Facility: Notification: Commonwealth Edison Co. MR Number: 3-95-0178 Byron 1 2 Date: 12/06/95 Byron,Illinois RI DISCUSSION WITH LICENSEE Dockets: 50-454,50-455 PWR/W-4-LP,PWR/W-4-LP Subject: INTERMITTENT FAILUE OF DIESEL GENERATOR RELAYS Discussion: On November 22, 1995, with Unit 1 in Mode 5 and Unit 2 in Mode 1, the licensee identified a problem with the Diesel Generators (DG) Agastat relays. In pursuit of a root cause for three relay failures over the past year, the licensee's laboratory identified a cold solder joint which would create an intermittent open under certain conditions. All three relays were from the same lot, believed to contain 130 relays manufactured by Agastat (currently owned by Amerace). The licensee had 100 relays from this lot installed in three DGs (1A, 2A, and 2B). As a result of the cold solder joint identification, the licensee replaced 26 relays in 2A DG, ten of which were tested and identified as defective. The discovery of 10 out of 26 relays to be defective caused the licensee to declare 1A and 2B DG inoperable (1A contains 43 of the suspect relays and 2B contains 31). The licensee immediately repaired the relays removed from 2A DG and repaired 2B DG. The licensee originally identified the intermittent open during a test which changed the temperature of the relay. The current method of testing is to attach the relay to an oscilloscope and move the suspect wire/solderjoint. The relays were Agastat EGPDRC relays which provide various control functions to start, run, and shutdown the DGs. The date code of the lot is 9245 (manufactured during week 45 of 1992). The lot is believed to be entirely contained in the licensee's system due to the manufacturing practices of the manufacturer which custom makes relays for a particular purchase order. However, the nature of the failure indicates a potential process problem during manufacturing. This could lead to similar problems with other lots, although no other problems with other lots have been identified by the licensee. The licensee corporate office is considering a Part 21 notification. Regional Action: The residents will continue to monitor the licensee's actions. Contact: LEWIS MILLER (708)829-9629 _ REGION III MORNING REPORT PAGE 5 DECEMBER 6, 1995 Licensee/Facility: Notification: MR Number: 3-95-0179 Advanced Medical Systems, Inc. Date: 12/06/95 Cleveland,Ohio BY TELEPHONE Dockets: 03016055 License No: 34-19089-01 Subject: WATER PROBLEMS AT ADVANCED MEDICAL SYSTESM, INC. (UPDATE) Discussion: On November 8, 1995, Northeast Ohio Regional Sewer District (NEORSD) informed NRC that Advanced Medical Systems, Inc. (AMS) planned to release 3,000 gallons of stored run-off water onto AMS' parking lot. On November 13, 1995, NEORSD obtained a Temporary Restraining Order (TRO) prohibiting AMS from releasing any stored water. On December 5, 1995, the TRO was lifted with the following stipulations: (1) AMS is allowed to discharge approximately 20,000 gallons of water containing no detectable cobalt-60 from two outdoor storage tanks, and (2) further discharges are prohibited until NEORSD and AMS agree on a release concentration. On December 5, 1995, AMS discharged approximately 3000 gallons of water to its back parking lot. Today, AMS will discharge an additional 17,000 gallons. No further discharges will be made until NEORSD and AMS agree on a release concentration. This information is current as of 9:00 a.m. (CDT) December 6, 1995. Contact: JOHN MADERA (708)829-9834 MICHAEL WEBER (708)829-9825 _ REGION IV MORNING REPORT PAGE 6 DECEMBER 6, 1995 Licensee/Facility: Notification: Texas Utilities Electric Co. MR Number: 4-95-0155 Comanche Peak 2 Date: 12/06/95 Glen Rose,Texas Dockets: 50-446 PWR/W-4-LP Subject: AUTOMATIC TURBINE AND REACTOR TRIP OF COMANCHE PEAK STEAM ELECTRIC STATION UNIT 2 Reportable Event Number: 29670 Discussion: On December 5, 1995, Comanche Peak, Unit 2, experienced a reactor trip initiated by a low-low level in Steam Generator (SG) 2-03 approximately 1 minute after a manual trip of Main Feedwater Pump (MFP) 2A. While the licensee was setting up to perform troubleshooting on the MFP 2A speed control servo mechanism which was believed to have failed, the MFP 2A turbine control valve began to cycle open and shut repeatedly. In accordance with previously discussed contingency actions, operators manually tripped the MFP 2A. The plant ran back from 100 percent to 60 percent power as expected. Approximately 1 minute after the runback, erratic steam dump operation resulted in excessive shrink of all SG levels. The unit automatically tripped due to low-low level in SG 3. All rods fully inserted and all auxiliary feedwater pumps started as designed. The licensee placed the steam dumps in the steam pressure mode of operation and they appeared to work properly in that mode of operation. Troubleshooting continues on the erratic operation observed while in the Tave mode. Reactor Coolant Pump (RCP) 1 tripped from Phase B and C instantaneous overcurrent when the nonsafeguards buses fast transferred from the unit auxiliary transformer to the startup transformer. Initial troubleshooting indicated that no apparent RCP motor or RCP control failure or damage occurred. The licensee experienced a similar trip of RCP 1 during a fast bus transfer in August 1994 and believes that this may be a result of a poorly timed fast bus transfer or improperly set overcurrent trip. The licensee is continuing the troubleshooting of the RCP trip and may delay extensive troubleshooting until the next Unit 2 refueling outage scheduled for this spring. The RCP was restarted and was operating satisfactorily. East Bus 345kV experienced a lockout similar to a lockout which occurred during a Unit 1 reactor trip on November 19 (See EN 29621). Both the November 19 Unit 1 and December 5 Unit 2 trips were complicated by a loss of one half of Switchyard Buses 345kV. The licensee found that the result of the loss of one bus in each trip was due to switchyard breaker pole disagreement. Switchyard breaker pole disagreement protective relaying is designed to initiate when one pole of a breaker operates slower than the other two and the protective relay circuit senses continued and unexpected voltage on the bus from the unit main transformer (potentially still connected to the switchyard bus). Following a seven cycle delay (approximately 116 milliseconds), the protective relaying deenergizes the switchyard bus by opening all of its REGION IV MORNING REPORT PAGE 7 DECEMBER 6, 1995 MR Number: 4-95-0155 (cont.) supply breakers in an effort to isolate the perceived fault. As a result, the opposite unit breaker supplying that switchyard bus is designed to open, as it did in both trips. The licensee has implemented a task team to investigate the cause of these failures and performed cleaning and lubrication of the two Unit 2 main transformer breakers. Following maintenance on the two Unit 2 main transformer breakers, the licensee performed pole timing tests to verify that they were set properly, and the electrical lineup was restored to normal. Several minutes following the plant trip, MFP 2B tripped for unknown reasons. The licensee continues its investigation of the MFP 2B trip. Work activities currently being performed include the MFP, RCP, and Steam Dump System troubleshooting, maintenance on the main steam isolation Valve 4 hydraulic actuator, and some valve rework. The licensee is currently making preparations for restart of Unit 2 contingent upon determination of root cause and repair of the steam dump system and at least one main feedwater pump. Regional Action: The senior resident inspector was in the control room at the time of the trip. The residents will continue to monitor the licensee's corrective actions and preparations for restart. Contact: A. T. Gody, Jr. (817)897-1500 _ REGION IV MORNING REPORT PAGE 7 DECEMBER 6, 1995 Licensee/Facility: Notification: Entergy Operations, Inc. MR Number: 4-95-0156 Arkansas Nuclear 2 Date: 12/06/95 Russelville,Arkansas Resident Inspector Dockets: 50-368 PWR/CE Subject: UNIT RESTART FOLLOWING REPAIR OF FEEDWATER PUMP TURBINE AND COMPONENT COOLING WATER LEAK Discussion: On December 6, 1995 at approximately 6:01 a.m. (CST), the licensee closed the generator output breaker, after a reduction in power to return Feedwater Pump A to service, followed by a reactor shut down to repair a component cooling water (CCW) leak in containment. On November 26, 1995, at 1 percent power, Feedwater Pump A appeared to be seized while on the turning gear. The licensee determined that a bolt cover had become dislodged and wedged between the rotating blades and the stationary nozzle block. The licensee removed the turbine rotating assembly for Feedwater Pump A and shipped it offsite for repair. On December 3, the licensee increased power to 79 percent (maximum power allowed with one feedwater pump operating). On December 4, the licensee again reduced power to approximately 1 percent to put the repaired Feedwater Pump A back into service. While at reduced power, licensee personnel entered containment to repair a small CCW leak (approximately 1/2 gpm) in the component cooling water system. On December 5, the licensee conducted a manual shutdown of the reactor to repair the CCW leak, which was found to be in the coupling to the oil cooler for the lower motor bearing of Reactor Coolant Pump A. The licensee began restart late on December 5, and the reactor went critical at 12:35 a.m., on December 6, 1995. Regional Action: Routine resident followup of power ascension. Contact: T. Reis (817)860-8185 _