Headquarters Daily Report SEPTEMBER 14, 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 SEP. 14, 1995 MR Number: H-95-0121 NRR DAILY REPORT ITEM SIGNIFICANT EVENTS Subject: SWITCHGEAR FIRE AND PARTIAL LOSS OF OFFSITE POWER The NRR/AEOD/RES Events Assessment Panel on September 5, 1995, has classified the switchgear fire and partial loss of offsite power at Waterford, Unit 3, as a Significant Event for the NRC Performance Indicator Program. The basis for Significant Event classification is a trip with complications including programmatic weaknesses in the licensee's response by the fire brigade to the switchgear fire, the licensee's control of the fast bus transfer design, and the licensee's maintenance of the shutdown cooling valves. On June 10, 1995, Waterford 3 was operating at 100 percent power with an operations staff consisting of a shift supervisor (SS), a control room supervisor (CRS), and two reactor operators. At 8:58 a.m. a generator trip occurred in response to failure of a lightning arrester on a remote offsite substation transformer. The generator trip resulted in a fast transfer activation. The 6.9 kV A1 bus and 4.16 kV A2 bus failed to transfer as designed. A fire and electrical fault occurred on the 4.16 kV A2 bus normal power supply breaker. The 6.9 kV A1 bus alternate supply breaker failed to close resulting in a loss of power to reactor coolant pumps 1A and 2A. This circumstance resulted in a reactor trip and a loss of offsite power to the 4.16 kV nonsafety-related A2 bus and the associated 4.16 kV safety-related A3 bus. Emergency Diesel Generator A started and loaded to power the A3 bus. At 9:06 a.m., an auxiliary operator informed the control room of heavy smoke within the turbine generator building. At that time, the SS did not activate the plant fire alarm or dispatch the fire brigade, but directed two auxiliary operators to don protective gear and investigate whether a fire existed. At 9:35 a.m., the operators reported seeing flames above the A2 switchgear and the SS activated the fire brigade. Operators requested assistance from the local offsite fire department and declared an Unusual Event in accordance with emergency response procedures. The fire brigade was unable to suppress the fire using portable fire extinguishers. The offsite fire department arrived on the scene at 9:58 a.m. and extinguished the fire with water at 10:22 a.m., after the A2 bus was deenergized. A reflash occurred which had to be put out with water a second time. During the cooldown transition from Mode 4 to Mode 5, operators discovered that the isolation valves for both trains of shutdown cooling did not operate properly. The plant cooldown to Mode 5 was delayed approximately 38 hours while these valves were repaired. During the period of June 13-16, 1995, the NRC conducted an augmented inspection team (AIT) inspection to determine the causes, conditions, and circumstances relevant to this event. The AIT identified three primary issues: fire protection, fast bus transfer design, and shutdown cooling valve inoperability. Information notice 95-33, "Switchgear Fire and Partial Loss of Offsite Power at Waterford Generating Station, Unit 3," has been issued to alert HEADQUARTERS MORNING REPORT PAGE 2 SEP. 14, 1995 MR Number: H-95-0121 (cont.) licensees to this event. Additional information on this event is available in Inspection Reports 50-382/95-15 and 50-382/95-17 and the Events Tracking System entry for 10 CFR 50.72 report number 28923. Subsequent to the issuance of Information Notice 95-33, the NRC conducted a follow-up inspection at the Waterford site. At that time, the licensee noted several clarifications to the information notice. The clarifications are as follows: 1. After the offsite fire department extinguished the fire at 10:22 a.m., a reflash occurred which had to be extinguished a second time with water. 2. The reluctance of the plant operators to apply water to the switchgear fire was in part due to the fact that the other electrical train's associated switchgear was in the same room. 3. The 6.9 kV A1 bus never transferred due to an as yet unidentified independent failure. The failure of the A1 bus to transfer was the cause of the underspeed condition on the associated reactor coolant pumps. Contact: Eric J. Benner, NRR/DRPM/PECB (301) 415-1171 _ REGION III MORNING REPORT PAGE 2 SEPTEMBER 14, 1995 Licensee/Facility: Notification: Consumers Power Co. MR Number: 3-95-0152 Big Rock Point 1 Date: 09/13/95 Charlevoix,Michigan RESIDENT INSPECTOR VIA TELEPHONE Dockets: 50-155 BWR/GE-1 Subject: OVERPRESSURIZATION OF PLASTIC PIPE CONTAINING CONTAMINATED RESIN RESULTING IN PIPE BURST AND RESIN RELEASE Discussion: At approximately 0800 on 9/13/95, a resin spill occurred in a tented enclosure outside of the turbine building. A vendor employee and a utility employee (health physics technician) were attempting to remove a blockage from a 90 degree elbow on the suction side pipe of a pump which was being used to transfer contaminated resin from a tank to a high integrity container (HIC). A metal fitting was attached to the pipe between the pump and the blockage. The workers first attempted to remove the blockage by connecting plant service water to the metal fitting. When this failed to remove the blockage, the workers attached a compressed air hose to the fitting. The resultant pressure in the plastic pipe caused the pipe to fail at a threaded fitting of the elbow which contained the blockage (duct tape). The licensee estimated that two liters or less of the contaminated resin in the pipe between the threaded fitting and the metal fitting was blown throughout the tented enclosure and contaminated both workers. The workers were successfully decontaminated and whole body counts showed that little, if any, intake occurred. The licensee's initial survey of the area surrounding the tented enclosure found no contamination, although the interior of the enclosure was extensively contaminated with numerous puddles of resin and water in the enclosure. The licensee stopped work on this job and conducted a critique of the event. Worker whole body counts are being evaluated, decontamination of the contaminated areas is under way and new procedures are being prepared to provide guidance when blockages in pipes are encountered. Regional Action: Resident and regional inspectors along with regional management will monitor the licensee's investigation and corrective actions. Contact: ROY J. CANIANO (708)829-9804 JAMES CALDWELL (708)829-9801 _