Headquarters Daily report NOVEMBER 03, 1994 *************************************************************************** REPORT NEGATIVE NO INPUT ATTACHED INPUT RECEIVED RECEIVED HEADQUARTERS X REGION I X REGION II X REGION III X REGION IV X *************************************************************************** PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION NOVEMBER 3, 1994 MR Number: H-94-0098 NRR DAILY REPORT ITEM SIGNIFICANT EVENTS EVENTS ASSESSMENT BRANCH DIVISION OF OPERATING REACTOR SUPPORT Subject: Loss of All Offsite AC Power for Two Units from Switchyard Maintenance The NRR/AEOD Events Assessment Panel on November 1, 1994, has classified the loss of AC power at Beaver Valley Units 1 and 2 as a Significant Event for the Performance Indicator Program. Classification was based on the conditional core damage probability resulting from loss all offsite AC power to the operating Unit 1 and the shutdown Unit 2 during a switchyard maintenance activity. On October 12, 1993, while Unit 1 was at full power, a maintenance crew was working on one of the Unit 2 main output breakers. This breaker was tagged out but dc control power remained available. The maintenance crew had replaced the mechanical linkage for a stack of auxiliary contacts which was found cracked during a routine inspection. During post maintenance testing, the technician inadvertently set up a path to supply 125 vDC power, through the test meter, to the substation under-frequency tripping relays. The under-frequency relays tripped open ten breakers in the Beaver Valley substation, causing the shedding of 90% load on Unit 1. The load reduction and loss of synchronization caused a rapid increase in turbine frequency which caused the reactor coolant pumps to accelerate. This caused an increase in reactor coolant flow, a power excursion and a reactor trip on high neutron flux rate. Within milliseconds after the reactor trip, the turbine tripped on mechanical overspeed (110%). The turbine electrical overspeed trip also functioned when the turbine reached 111% of its rated speed. The load shedding and the Unit 1 trip caused a loss of offsite power at both units. Offsite power was recovered at both units within nine minutes. All safety systems at Unit 1 functioned as designed. Unit 2 had one available emergency diesel generator that started and sequenced power to vital shutdown loads. The function of the under-frequency relays was to shed designated transmission lines when grid frequency drops due to system overload. The intent was to shed enough load to restore grid frequency and thus allow the Beaver Valley units to remain on-line. The licensee is reevaluating the design. The conditional core damage probability (CCDP) for the operating unit was estimated to be 6E-05 (NRR/SPSB). The event sequence contributing principally to risk was loss of offsite power, failure of emergency power, successful auxiliary feedwater actuation, RCP seal LOCA, and failure to recover AC power long term. CONTACT: Thomas Koshy, NRR/DOPS/OECB (301) 504-1176 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION NOVEMBER 3, 1994 MR Number: H-94-0099 NRR DAILY REPORT ITEM SIGNIFICANT EVENTS EVENTS ASSESSMENT BRANCH DIVISION OF OPERATING REACTOR SUPPORT Subject: Single Failure of a Control Rod to Scram The NRR/AEOD Events Assessment Panel on October 18, 1994, classified the single control rod failure to scram at Quad Cities as a Significant Event for the NRC Performance Indicator Program. The classification was based on the willingness of licensee maintenance personnel to work outside of written procedures during testing of scram valves and licensee management lack of understanding that the work practice inhibited not only the normal scram system from scramming the rod, but the back up scram system and the alternate rod insertion (ARI) system as well. On August 29, 1994, a control rod failed to scram during scram time testing. Licensee investigation found a pipe plug installed in the exhaust port of the scram solenoid pilot valve (SSPV). The plug had been installed as part of the testing of the scram inlet and outlet valves after they had been refurbished during the refueling outage. The test procedure calls for a temporary air supply to be connected to the top of the scram inlet and outlet valves to ensure the valves operate properly and have the specified differential pressure between them before they are reconnected to the control rod hydraulic control unit. Contrary to the procedure, the maintenance technicians reconnected the normal air supply line and pressurized the scram inlet and outlet valves. In order to pressurize the scram valves in this manner, it is necessary to plug the exhaust port of the associated SSPV. After the test is completed, the workers normally remove the plug. Through interviews with several maintenance workers, the NRC resident inspector determined that this way of testing the valves was common practice and considered within the skill of the craft, and the procedure written to test the valves was not used. The licensee root cause team did not consider the event significant because they believed that the back up scram and the ARI systems were available to scram the rod if an actual scram were required. They recommended that the installation and removal of the pipe plug be incorporated into the test procedure, since that was how the valves were actually being tested. Over the next three weeks, the resident inspector questioned the licensee about the ability of the back up scram and ARI systems to scram the rod. The licensee assured the inspector that those systems would scram the rod, even with the plug installed in the SSPV. The inspector finally asked that a licensee representative familiar with the scram systems explain in detail how the back up scram and the ARI systems worked. When the licensee representative began to explain the systems, he realized that they would not scram the rod if the SSPV exhaust port were blocked and the SSPVs operated properly. At that time, about a month after the event occurred, the licensee determined that the event was reportable and a 50.72 notification was made. This issue was one of several recent personnel performance issues that have occurred at the site. The site vice president decided to shut down both units on October 2, 1994, because of poor personnel performance. Both units remain shut down while the personnel issues are addressed and a generic problem with the SSPVs is resolved by replacement of the SSPV diaphragms. The licensee plans to restart the units in late October or early November 1994. The Events Assessment and Generic Communications Branch (OECB) did not perform a probabilistic safety assessment for this event because it was impractical to extrapolate the single failure of the control rod to a large number of rods. A walkdown of the system was performed and only the one pipe plug was found. Also, the problem is self-revealing during the scram time testing that is required at 20-25% power during start up. Therefore, it is not likely that the reactor could be operated at higher power with the plug installed. CONTACT: David L. Skeen, NRR/DOPS/OECB (301) 504-1174 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION I NOVEMBER 3, 1994 Licensee/Facility: Notification: New Hampshire Yankee MR Number: 1-94-0123 Seabrook 1 Date: 11/02/94 Manchester,New Hampshire SRI E-MAIL Dockets: 50-443 PWR/W-4-LP Subject: UPDATE TO MR 1-94-0108: SENSITIZED STAINLESS STEEL BOLTING IN SERVICE WATER PUMPS Reportable Event Number: 27973 Discussion: Based on two severely degraded cooling tower pump column bolts, North Atlantic performed an operability evaluation for the service water pumps and established an aggressive repair plan to remove all six service water pumps, one at a time, to inspect and replace all pump bolting. The NRC reviewed the operability evaluation and repair plan and determined that the licensee's corrective actions were commensurate with the safety significance of the issue. Inspection of the four service water ocean pumps (SW-41-A,B,C,D) last month revealed no severely degraded bolts. Several column flange bolts were identified to have minor degradation due to intergranular corrosion. On 11/1/94, North Atlantic removed the "A" service water cooling tower pump (SW-P-110A) to inspect and replace all existing bolting due to potentially severe degradation from a intergranular corrosion mechanism. Of 112 total submerged pump column bolts 45 bolts (40% of the total population) were severely degraded (12 bolts broke during removal). The operators immediately declared the "B" cooling tower pump inoperable placing the plant in a 72 hour shutdown limiting condition for operation (LCO) based on the condition of the "A" pump. The maintenance staff replaced SW-P-110A with a rebuilt pump that had all new bolting. Following completion of the pump head curve verification and operability surveillance tests, the operators returned the pump to an operable status on 11/2. At that time, the 72 hour LCO was exited; however, the plant will maintain the 7 day LCO entered on 10/30/94 at 11:38 pm for SW-P-110A until the "B" cooling tower pump bolting is corrected. North Atlantic has committed to submit a final report to the NRC regional office to explain the failure mechanism and the bolt supplier implications. Regional Action: The resident inspectors observed the service water pump work to date, including visual examination of bolting on each pump. The NRR project manager is aware of the issue and has informed the Vendor Inspection Branch, relative to generic concerns. The severe bolt degradation seems to be limited to the cooling tower environment. The licensee is not planning on making a press release. Contact: John Rogge (610)337-5146 Richard Laura (603)474-3589 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION I NOVEMBER 3, 1994 Licensee/Facility: Notification: Maine Yankee Atomic Power Co. MR Number: 1-94-0122 Maine Yankee 1 Date: 11/02/94 Wiscasset,Maine SRI/TELEPHONE CALL Dockets: 50-309 PWR/CE Subject: PLANT SHUTDOWN Reportable Event Number: N/A Discussion: On November 1, 1994, at about 9:30 p.m., Maine Yankee commenced a plant shutdown. This shutdown was necessitated by a "pin hole" steam leak from the "cross under" pipe between the high pressure turbine and moisture separator reheater (MSR) No. 18C. After removing insulation around the leak area and performing UT inspection, Maine Yankee found that areas of piping around the hole were below minimum wall thickness. Initial investigations revealed that the leak is located in a portion of piping that is not covered by the erosion/corrosion program. The plant will make necessary repairs and perform other maintenance activities. A detailed schedule for the shutdown is being prepared. Regional Action: The resident inspectors are following facility activities. Contact: William Lazarus (610)337-5231 Jimi Yerokun (207)882-7519 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION II NOVEMBER 3, 1994 Licensee/Facility: Notification: Entergy Operations, Inc. MR Number: 2-94-0091 Grand Gulf 1 Date: 11/03/94 Port Gibson,Mississippi Dockets: 50-416 BWR/GE-6 Subject: FOLLOWUP TO REACTOR SCRAM ON NOVEMBER 1, 1994 Reportable Event Number: 27972 Discussion: The reactor scrammed on November 1, 1994, at 8:20 p.m. (CST) during a Division 1 Reactor Protection System I&C surveillance (Reactor high pressure). When Division 1 was tripped during the surveillance, a full scram occurred. There were no indicated Division 2 trips prior to the surveillance being performed. After the scram, the licensee had problems with the feedwater system and the operators took manual control on one string of feedwater heaters to maintain reactor water level. Subsequently, the "A" feedwater pump tripped at +53" (Setpoint was 53.5") which was within allowable tolerance. The licensee has determined the cause to be a grounding problem on the "A" backup scram valve control circuitry. This ground, in conjunction with a newly upgraded 125 vdc ground detection device, enabled enough current flow to energize and thus open the "A" backup scram valve when the Division 1 half scram was present. The licensee has removed the ground, modified the detection circuitry, and will evaluate other detection circuitry for similar problems. The plant went critical around 1:24 a.m. (CST) on November 3, 1994, and expects to be on-line around 3:00 p.m. today. Regional Action: The Resident Inspectors responded to the site November 1, 1994, and are following licensee actions. Contact: F. S. CANTRELL (404)331-5534 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION III NOVEMBER 3, 1994 Licensee/Facility: Notification: Commonwealth Edison Co. MR Number: 3-94-0200 Zion 1 Date: 11/03/94 Zion,Illinois Dockets: 50-295 PWR/W-4-LP Subject: SHUTDOWN FOR FORCED OUTAGE Reportable Event Number: N/A Discussion: Discussion: On November 2, 1994, Unit 1 commenced a forced shutdown to repair an oil leak on the exciter skid provided by Westinghouse. Additional work will be performed as specified in the forced outage schedule. A licensee investigation into the cause of the leak is also planned. The outage is scheduled for 24-48 hours in duration. During the shutdown, 1FW0053 (feedwater containment isolation to 1C Steam Generator) tripped on thermal overload. The valve was declared inoperable. The valve has been opened and is being used to feed SG 1C. This places Unit 1 in a 36 hour to Mode 4 LCO for containment isolation, beginning at 0250, November 3, 1994. Contact: M. HUBER (708)746-2313 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION III NOVEMBER 3, 1994 Licensee/Facility: Notification: Commonwealth Edison Co. MR Number: 3-94-0201 Byron 1 Date: 11/03/94 Byron,Illinois Dockets: 50-454 PWR/W-4-LP Subject: END OF REFUELING OUTAGE (B1R06) Reportable Event Number: N/A Discussion: Discussion: On November 2, 1994, at 5:09 a.m. (CST) Unit 1 was synchronized to the grid. This ended a 55 day refueling outage. Major items completed during the outage included: -- cycle 7 core load -- approximately 900 Steam Generator (SG) tubes plugged -- Steam Generators chemically cleaned, removed approximately 3600 pound of iron oxide from each SG -- The 1B hot leg wide range temperature instrument was repaired, exiting an emergency Technical Specification (TS) issued in August 1994. During the startup, the 1A motor driven feedwater pump was started but had to be secured immediately due to a feedwater leak from the casing drain. The water sprayed on a transformer/MCC Panel and power was removed from the transformer. The vacuum pump for the main condenser was started to maintain vacuum and the main turbine was latched and returned to higher rpm, allowing the shaft driven oil pump to supply bearing oil. The 1B turbine driven feed pump was placed in service and the startup continued. Cause of the leak is under investigation by the licensee. Regional Action: Residents will followup the feedwater leak. End of Outage is for information only. Contact: Lew Miller (708)929-9629 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION III NOVEMBER 3, 1994 Licensee/Facility: Notification: Mpi MR Number: 3-94-0202 Milwaukee Pharmacy Date: 11/03/94 Milwaukee,Wisconsin Dockets: 03031790 License No: 48-26240-01MD Subject: RECEIPT OF A CONTAMINATED PACKAGE CONTAINING RADIOACTIVE MATERIAL Reportable Event Number: N/A Discussion: On October 26, 1994, a package was picked up at Amersham in Arlington Heights, Illinois by a driver from the Chicago MPI pharmacy. The package contained 11 vials of thallium with a total activity of approximately 154 millicuries. Chicago pharmacy personnel surveyed and wiped the package prior to opening. The results were negative. The package was opened and determined to belong to the Milwaukee pharmacy. It was resealed, surveyed and returned to Amersham. The resurvey was negative. The package was transported to the Milwaukee pharmancy. Prior to opening the package Milwaukee personnel survey and wet wiped the package. Contamination was found on the top and bottom external surfaces of the package. Maximum detected activity was 41000 dmp/cm2. There was no contamination on the interior of the box. The contamination was determined to be Iodine-131. According to the corporate RSO, the Chicago pharmacy, the Amersham dock area, both drivers and their vehicles, and the Milwaukee pharmacy were surveyed and the source of contamination was not found. Amersham does not handel Iodine-131. The Milwaukee pharmacy dispensed one 10 microcurie dose of I-131 on 10/25/94, however, surveys and wipes were performed before the package arrived. The results were negative. The Chicago pharmacy dispensed a total of 20 millicuries of I-131 after 5 p.m. on 10/25/94. MPI Pharmacy Services, Inc., personnel will continue to followup on this issue. Regional Action: Region III will monitor MPI's followup of this matter. NMSS, the Regional States Agreement Officer, and the Illinois Department of Nuclear Safety have been notified. Contact: Toye Simmons (708)829-9842