Headquarters Daily report APRIL 13, 1995 *************************************************************************** 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 APRIL 13, 1995 MR Number: H-95-0088 NRR DAILY REPORT ITEM SIGNIFICANT EVENTS EVENTS ASSESSMENT BRANCH DIVISION OF OPERATING REACTOR SUPPORT Subject: POTENTIAL FOR HYDROGEN ENTRAINMENT IN EMERGENCY CORE COOLING SYSTEM PUMPS The NRR/AEOD Events Assessment Panel meeting on April 11, 1995, classified the unauthorized testing of the make up and purification system by licensed operators at Crystal River, Unit 3, as a Significant Event. Classification was based on the programmatic failure that led to licensed operators conducting unauthorized experiments. The hydrogen pressure in the makeup and purification tank (MUT) is required to be maintained in a critical band, in relation to its level, to prevent safety injection (SI) pump cavitation during SI initiation and transition to containment sump recirculation. This required frequent pressure adjustments when MUT tank level varied during plant operation. The operating crew was not convinced of the basis in the pressure band provided by engineering and was unable to get a prompt response from engineering. On September 4, 1994, in order to substantiate the operations' argument on incorrect engineering assumptions, they conducted an experiment to vary MUT level which caused hydrogen pressure to be outside the required band. The operators considered this action to be a plant evolution and not a design limit violation. Licensee management later identified this action as operation outside the design basis and made a 50.72 notification to NRC. The licensee provided interim guidelines on the hydrogen pressure band to the operators and is working on a permanent solution. CONTACT: Thomas Koshy, NRR/DOPS/OECB (301) 415-1176 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION APRIL 13, 1995 MR Number: H-95-0089 NRR DAILY REPORT ITEM SIGNIFICANT EVENTS EVENTS ASSESSMENT BRANCH DIVISION OF OPERATING REACTOR SUPPORT Subject: INADEQUATE CONTROL OF SWITCHYARD ACTIVITIES The NRR/AEOD Events Assessment Panel meeting on April 11, 1995, classified the lack of adequate control of switchyard activities at San Onofre Nuclear Generating Station (SONGS), Unit 2, on February 16, 1995 as a Significant Event for the Performance Indicator Program. The significant event classification was based on the apparent programmatic weaknesses in the licensee's management of plant activities. On February 16, 1995, an NRC inspector (a member of the Maintenance team inspection at SONGS) noticed eight vehicles in the switchyard. The vehicles included cherry pickers and two switchyard workers' personal vehicles. The switchyard is shared by SONGS Units 2 and 3. Unit 3 was operating at full power, and Unit 2 was in Mode 5, mid-loop operations. The licensee concluded that the Unit 2 time to boil following loss of all ac power was 17 minutes, and the time to uncovering of the core was 2.5 hours. One of the two Unit 2 emergency diesel generators (EDGs) had been removed from service for maintenance, leaving one onsite ac power source available. Two independent offsite ac power sources were operable. The licensee has the ability to crosstie Unit 2 class 1E loads to the Unit 3 EDGs, but about an hour is required to establish this cross-connection. The licensee switchyard control procedures allow workmen and their vehicles (but no personal vehicles) in the switchyard regardless of the status of either unit. Workmen planning to enter the switchyard are required to contact the control room and get permission before entering. The switchyard workmen did not contact the control room until after they had entered the switchyard. (There is a sign on the gate directing that no entry be made without control room authorization.) Even after the control room was contacted, the shift superintendent did not realize how many vehicles were in the switchyard, nor did he know that the workmen had entered the wrong entrance for the type of work they were planning to perform. In a tele-conference, the licensee stated that no single mishap in the switchyard could result in the loss of both sources of AC power to Unit 2, due to location of switchyard equipment and the fast transfer capability from the Unit 2 switchyard side to the Unit 3 side. The licensee prepared an after-the-fact PRA to analyze the risk implications of this event. The licensee assumed that the switchyard work resulted in a ten-fold increase in the frequency of a plant-centered loss of offsite power (LOOP). The probability of a LOOP due to accidents outside the plant area was not changed. The value used by licensee for plant-centered LOOP was 4E-4/yr. This value is from NRC NUREG-1410. This value was increased to 4E-3/yr for the after-the-fact study. The licensee's analysis indicated an increase in the probability of inventory boiling and core damage of 3% - 5%. The licensee states that this increase is small because of the relatively small contribution of the plant-centered LOOP to the overall core damage frequency. The NRR staff is evaluating the licensee's analysis. This event is classified as a "Significant Event" for the performance indicator program. Entering the switchyard without authorization and having personal vehicles in the switchyard is indicative of a programmatic breakdown. The staff is concerned with the increased potential for switchyard accidents as a result of vehicular traffic. This concern is elevated when switchyard activities are conducted in parallel with mid-loop operations, particularly early into an outage. (The licensee stated that postponement of the switchyard work would not have increased the length of the outage.) In light of the Vogtle LOOP that resulted from a switchyard mishap and the resulting difficult recovery the Vogtle licensee experienced, the staff expects other licensees to have heightened sensitivity to the potential for problems occurring while conducting switchyard work early into an outage and during mid-loop operations. CONTACT: E.N. Fields, NRR/DOPS/OECB (301) 415-1173 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION I APRIL 13, 1995 Licensee/Facility: Notification: Veterans Administration Medical MR Number: 1-95-0054 Center Date: 04/12/95 Veterans Administration Medical Ctr Buffalo,New York Dockets: 07001331 License No: SNM-1305 Subject: REPORTED APPARENT LOSS OF TWO NUCLEAR PACEMAKERS Reportable Event Number: N/A Discussion: On April 10, 1995, the Radiation Safety Officer (RSO) of the Veterans Administration Medical Center in Buffalo, New York (VA-Buffalo) notified Region I that, during an internal review of their nuclear pacemaker program, they identified two patients who had received implants at VA-Buffalo and later died, and the disposition of the nuclear pacemakers is currently unknown. VA-Buffalo records reportedly indicate that one patient died in 1983 and the second patient died in 1986. The RSO stated that VA-Buffalo is currently trying to contact the physicians and medical institutions who provided care for these patients at the time of their deaths, as well as the patient's next of kin, in an attempt to locate the pacemakers. The pacemakers each contain approximately 150 milligrams of plutonium-238. VA-Buffalo's internal review was prompted by Region I following a determination that the licensee had discontinued follow up on several nuclear pacemaker patients. The RSO stated that the responsibility for pacemaker patient follow up had been transferred to Veterans Administration (VA) and non-VA facilities and, in at least one case, a private physician's group. Region I advised VA-Buffalo that this responsibility could only be transferred to another nuclear pacemaker licensee. Region I is closely following this case. Regional Action: Enforcement action will be considered when the licensee's investigation is completed. Contact: Jenny M. Johansen (610)337-5304 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION II APRIL 13, 1995 Licensee/Facility: Notification: Entergy Operations, Inc. MR Number: 2-95-0044 Grand Gulf 1 Date: 04/13/95 Port Gibson,Mississippi Dockets: 50-416 BWR/GE-6 Subject: CABLE TRAY DAMAGE Reportable Event Number: N/A Discussion: On April 10, 1995, at 9:20 a.m., a turbine building operator noticed debris on the floor and that one of four circulating water pump room exhaust fans' motor had fallen on a cable tray which contained 4160 VAC electrical cables from one of the off-site power supply transformers ESF-12. The ESF-12 transformer was subsequently tagged out due to potential cable damage. No control room alarms or other indications of the problem occurred. This 115 KV off-site power source is one of three sources (the other two are 500 KV from transformers ESF-11 and ESF-21). The licensee's initial inspection found that a factory weld on a fastener for the fan mount had fatigue failed which allowed fan motor movement which induced the other fasteners to fail. Inspection of the electrical cables revealed that the outer rubber jacket on two of the nine cables was slightly damaged but the inner armor jacket was not penetrated. The cable tray was damaged to an extent which necessitated replacement. As of April 13, the cable tray has been replaced and the slight damage to the outer rubber jacket has been repaired for the two 4160 VAC cables. The licensee plans to return the ESF-12 transformer to standby service shortly. Since these exhaust fan mounts did not receive prior preventive maintenance inspections, the licensee is considering such. Regional Action: The resident inspectors will continue to followup on the licensee's action. Contact: R. BERNHARD (404)331-4664 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION III APRIL 13, 1995 Licensee/Facility: Notification: Commonwealth Edison Co. MR Number: 3-95-0063 La Salle 2 Date: 04/11/95 Marseilles,Illinois SRI VIA TELECON Dockets: 50-374 BWR/GE-5 Subject: MAIN STEAMLINE PLUG DROPPED ON TOP OF REACTOR CORE Reportable Event Number: N/A Discussion: At 7:00 p.m. on 4/11/95, with the unit shut down for refueling, removal of main steamline plugs (MSLP) was in progress for reactor vessel reassembly. During removal of the second MSLP, it came loose from the lifting strongback and fell approximately 32 feet onto the core. Maintenance personnel had verified that the strongback latches were locked by using an underwater camera. Water clarity was very low at the time of this event, but maintenance personnel said that the camera would be used even if the water was clear. ComEd did not yet have an explanation as to how the latches came open. The MSLP weighs about 250 pounds. The licensee subsequently conducted a visual inspection of the core with an underwater camera and no evidence of damage was found. The MSLP was transferred to the dryer separator pit and inspected. There was no indication of damage or missing components. Reactor water samples were taken and no abnormalities were noted. Also no evidence of a crud burst was present. Engineering personnel subsequently performed a more detailed video survey. This was forwarded to General Electric (GE) for review. Recommendations from GE for further inspections were expected by the end of 4/12/95. The two remaining MSLPs were successfully removed the next shift. The inspectors are reviewing the licensee's decisions to perform MSLP removal with reduced water clarity and to resume removal of the MSLPs, without understanding what had gone wrong. This decision was apparently made by the shift engineer later in the evening of 4/11/95. Regional Action: Resident and regional inspectors are following the licensee's investigation. Contact: L. MILLER (708)829-9629 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION III APRIL 13, 1995 Licensee/Facility: Notification: Northern States Power Co. MR Number: 3-95-0064 Prairie Island 1 2 Date: 04/13/95 Welch,Minnesota RI PC Dockets: 50-282,50-306 PWR/W-2-LP,PWR/W-2-LP Subject: PRAIRIE ISLAND DRY CASK STORAGE Reportable Event Number: N/A Discussion: On 4/12/95 the licensee successfully performed the dry run with the TN-40 spent fuel storage cask. This activity involved moving the cask in and out of the fuel pool and performing maneuvers simulating the loading/unloading of the cask. The NRC has scheduled a special team inspection during the week of 4/17/95 to review the licensee's Dry Cask Storage Program. Results of this inspection will be discussed with the licensee during an exit meeting on 4/28/95. This meeting will be held in Red Wing, Minnesota, and will be open for observation by the public. Regional Action: The NRC will continue to monitor the licensee's activities in this area. Contact: W. KROPP (708)829-9633