Headquarters Daily Report NOVEMBER 02, 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 - HEADQUARTERS NOV. 02, 1995 MR Number: H-95-0136 NRR DAILY REPORT ITEM SIGNIFICANT EVENTS Subject: SCRAM AND ASSOCIATED COMPLICATIONS AT LIMERICK, UNIT 1 The NRR/AEOD/RES Events Assessment Panel on October 31, 1995, classified the scram and associated complications that occurred on September 11, 1995 at Limerick, Unit 1, as a Significant Event. The significant event determination was based on the first-time nature of the initiating event and the degraded condition of the suppression pool. On September 11, 1995 when Limerick, Unit 1, was being operated at 100 percent power with the "A" loop of suppression pool cooling in operation to remove heat being dumped to the suppression pool by leaking safety/relief valves (SRVs), one SRV suddenly opened. SRVs leakage had existed for years and the licensee had been unable to eliminate the problem. After observing alarms and unsuccessfully attempting to close the SRV, the reactor was manually scrammed. Following the reactor scram, the "B" loop of suppression pool cooling was initiated. About 30 minutes into the transient, erratic operation of the "A" loop of suppression pool cooling was observed. The cause was promptly identified as potential clogging of the suction line strainer located in the suppression pool. Even though a cleaning of the suppression pool of Unit 2 earlier in 1995 disclosed a substantial amount of debris, no cleaning or inspection of the Unit 1 pool was performed during a subsequent short outage. An investigation following the event disclosed that there had been severe erosion damage to the pilot valve of the SRV that opened. The pilot valve disk above the seating portion had eroded completely through for 360 degrees so that the lower nose portion had separated from the remainder of the disk. Additional parts within the pilot valve also showed extensive erosion. The steam leak had existed for a long time and had increased greatly from that initially detected after its replacement and the subsequent testing required for reactor restart. Inspection of the suppression pool of Unit 1 showed a large amount of debris, comparable to that found earlier when Unit 2 was cleaned. The prudence of cleaning the pool had been identified in numerous staff generic communications, starting in late 1993. No pool cleaning or inspection was incorporated into the refueling outage (February 5 to March 11, 1994); however, cleaning was scheduled for a refueling outage in the spring of 1996. Unit 2 was cleaned during a refueling outage during the spring of 1995 and the results of the cleaning had not caused the licensee to advance the scheduled cleaning of Unit 1. Nor was there any inspection incorporated into a short duration outage of Unit 1 that occurred after the refueling outage of Unit 2. These situations are believed to be indicative of failure to recognize the severity of potential problems and take measures in sufficient time to eliminate the problems. Technical Contact: Jerry Carter, NRR/DRPM/PECB (301) 415-1153 HEADQUARTERS MORNING REPORT PAGE 2 NOV. 02, 1995 MR Number: H-95-0136 (cont.) _ HEADQUARTERS MORNING REPORT PAGE 2 NOVEMBER 2, 1995 MR Number: H-95-0137 NRR DAILY REPORT ITEM GENERIC COMMUNICATIONS Generic Letter 95-09, "MONITORING AND TRAINING OF SHIPPERS AND CARRIERS OF RADIOACTIVE MATERIALS," will be issued on November 3, 1995. This letter is being issued to all NRC licensees to address the question of training and monitoring of carrier personnel when they enter a licensee's restricted areas. Current policy has required each licensee to provide training and monitoring to carrier personnel entering their restricted areas. The letter informs licensees that it would be acceptable to use the monitoring and training provided by the carrier to satisfy these requirements, subject to certain provisions. Contacts: Sami Sherbini, NMSS Cynthia Jones, NMSS (301) 415-7902 (301) 415-7853 _ REGION II MORNING REPORT PAGE 3 NOVEMBER 2, 1995 Licensee/Facility: Notification: Engineering Consultant Services MR Number: 2-95-0090 An Agreement State Licensee Date: 11/02/95 Research Triangle Park,North Carolina Subject: RECOVERED STOLEN GAUGE - UPDATE TO PN 2-95-063 Discussion: On October 31, 1995, a representative of the State of North Carolina notified Region II that a model 3400 Troxler moisture/density gauge belonging to Engineering Consultant Services (ECS) Limited of Research Triangle Park, North Carolina had been stolen. The gauge containing 8 millicuries of cesium-137 and 40 millicuries of americium-241, was located in the rear of a pick up truck. The vehicle was stolen at approximately 7:00 a.m. on October 31, 1995, from a technician's house in Durham, NC. On November 1, 1995, at approximately 1:00 a.m., as a result of a nationwide auto search issued by the local police, the pick up truck was found with the gauge south of Richmond, Virginia. The vehicle was impounded by the police and personnel from ECS retrieved the vehicle along with the gauge. The RSO of ECS reported that the gauge appeared to be undamaged. The gauge will be returned to the manufacturer for further examination. Regional Action: The State of North Carolina has been informed. Contact: A. Jones (404)331-5565 _ REGION II MORNING REPORT PAGE 4 NOVEMBER 2, 1995 Licensee/Facility: Notification: Virginia Power Co. MR Number: 2-95-0091 North Anna 1 2 Date: 11/02/95 Richmond,Virginia Dockets: 50-338,50-339 PWR/W-3-LP,PWR/W-3-LP Subject: LAYOFF Discussion: On November 1, 1995, Virginia Electric and Power Company layed off 45 employees. Those involved were located at the North Anna and Surry plant sites in Louisa and Surry Counties, Virginia and at the corporate office in Richmond, Virginia. Almost all the layoffs were in the Quality Assurance area. A press release was issued by the Virginia Electric and Power Company in September 1995, announcing these planned reductions. Regional Action: Resident Inspector followup. Contact: Steve Tingen (404)331-5574 _ REGION III MORNING REPORT PAGE 5 NOVEMBER 2, 1995 Licensee/Facility: Notification: Commonwealth Edison Co. MR Number: 3-95-0165 La Salle 1 Date: 10/31/95 Marseilles,Illinois SRI VIA TELECON Dockets: 50-373 BWR/GE-5 Subject: ALERT DUE TO HIGH RADIATION IN THE REACTOR BUILDING Discussion: At 10:10 a.m. (CST), with the reactor at 96 percent power, a failure occurred on the 1B TIP machine. The licensee was running a TIP set for NI calibrations. During insertion of the 1B TIP detector the operator received indications that the detector was withdrawing. The operator attempted to stop the TIP, but was not successful. The TIP withdrew past its shielded storage location to the drive unit itself. A reactor building area radiation monitor (next to the drive units) pegged upscale (1 Rem/hr) and alarmed in the control room. At 10:14 the operators entered the EOP for secondary containment control (due to high radiation levels in the 740 ft elevation of the reactor building). Personnel were warned to stay clear of the area and at 10:25 a decision to evacuate both Unit 1 and 2 reactor buildings was made. At 10:35 an ALERT was declared based on the high radiation levels. The TSC and OSC were activated. The licensee subsequently established restricted high radiation and contamination boundaries in the reactor building. The initial plan is to let the TIP decay off and then determine the cause of the failure. The suspected cause is that the drive chain failed and the spring on the drive unit then retracted the TIP detector all the way out. It will be from 72 hours to 7 days before the licensee can inspect the drive unit and determine the cause of the failure. With plant conditions stable and radiological boundaries established, the licensee terminated the ALERT at 4 p.m. There was no impact on the operation of Unit 1 or 2 and they remained at full power. The event involved no radiological releases and no personnel exposures. The senior resident was present in the control room when the event occurred and monitored licensee performance. Region III was notified when the ALERT was declared and the other resident inspectors responded to the TSC and OSC. Regional Action: NRC entered the monitoring mode at 12 p.m. and dispatched an RP inspector to the site. NRC exited the monitoring mode at 3:40 p.m. October 31 after understanding the licensee's plans. The resident and regional inspectors are following the licensee's investigation of this event and evaluating corrective actions from the 1983 event. Contact: B. CLAYTON (708)829-9602 _ REGION IV MORNING REPORT PAGE 6 NOVEMBER 2, 1995 Licensee/Facility: Notification: Houston Lighting & Power Co. MR Number: 4-95-0135 South Texas 2 Date: 11/02/95 Wadsworth,Texas Resident Inspectors Dockets: 50-499 PWR/W-4-LP Subject: REACTOR PRESSURE VESSEL FLANGE SEAL RING (O-RING) LEAKAGE Discussion: On October 30, 1995, with the reactor in Mode 3, the licensee was continuing plant startup after completing its recent refueling outage. At approximately 6 p.m. (CST), the operators received a high temperature alarm from the reactor pressure vessel (RPV) flange seal leakoff drain. Investigation lead to the discovery that the RPV flange inner seal was leaking about 60 cc/minute. The operators isolated the RPV flange inner seal drain valves and the flange seal leakage appeared to stop. A short time later the operators noted that they were receiving fluctuating temperature indications of the flange seal leakoff piping, indicating RPV flange outer seal leakage. Further investigation indicated that leakage of 0-60 milliliters/minute had passed the flange outer seal, but had then stopped. During the remainder of October 30-31, two more occurrences of short-term leakage had been noted with subsequent sealing of the outer seal. The licensee has contacted Westinghouse (the RPV supplier) and the seal vendor concerning this problem. Westinghouse indicated that they had knowledge of intermittent leakage from flange seals and the seal ring vendor noted that intermittent leakage is not unheard of. The seal rings are self-energizing and will probably seal or, if some debris had been trapped in the sealing area, it would possibly be flushed out by the intermittent leak. If the leakage were to continue, the failure would be a slow degradation of the seal, not a catastrophic failure. The licensee's inspection of the RPV external flange area had not identified any leakage through the flange area. Since the discussions with Westinghouse and the seal vendor, the licensee has noted four more short occurrences of leakage, with the last one occurring at 12 a.m. on November 1, 1995. The licensee continues to monitor the concern as it continues plant startup. The licensee has installed television monitors, along with the existing temperature monitors, to provide continuous observation of the RPV flange area. The resident inspectors continue to monitor the plant startup and the RPV flange leakage. The Regional office has been briefed by the licensee on the flange leakage. Regional Action: For information only. Contact: John L. Pellet (817)860-8183 Ronald A. Kopriva (817)860-8104 _