Headquarters Daily Report AUGUST 07, 1998 *************************************************************************** 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 AUGUST 7, 1998 MR Number: H-98-0120 NRR DAILY REPORT ITEM GENERIC COMMUNICATIONS Revision 1 to Administrative Letter 96-05, "COMPLIANCE WITH THE RULE 'TIMELINESS IN DECOMMISSIONING OF MATERIAL FACILITIES,'" was issued on July 14, 1998. The revised letter was issued to all material and fuel cycle licensees to inform them that NRC will refrain from preparing an environmental impact statement until a formal license amendment request is received. In addition, it clarified when a decommissioning plan should be submitted and how the rule applies to "storage-only" and "possession-only" licenses. Contact: John T. Buckley, NMSS 301-415-6607 E-mail: jtb@nrc.gov _ REGION II MORNING REPORT PAGE 2 AUGUST 7, 1998 Licensee/Facility: Notification: Duke Power Co. MR Number: 2-98-0037 Catawba 1 Date: 08/07/98 York,South Carolina Dockets: 50-413 PWR/W-4-LP Subject: ICE CONDENSER RELATED UNIT SHUTDOWN Discussion: On August 7, 1998, at 9:35 a.m., Catawba Unit 1 began a forced shutdown when actions to clear/remove ice buildup from a number of its ice condenser ice bed flow channels could not be completed within the 48-hour Technical Specification (TS) action statement. (See Event Number 34614.) The Unit 1 ice condenser was declared inoperable on August 5, 1998, when a TS required surveillance identified a number of flow channels to be blocked by a buildup of ice greater than the 0.38 inch TS limit. In addition to the flow channel ice blockage problem, foreign material (i.e., three large plastic bags used in the ice basket refill process and some rope) was also found in several of the ice condenser bays. Unit 1 is scheduled to be off line by 3:00 p.m. today. Once the licensee completes the necessary actions to return the Unit 1 ice condenser to an operable status, they plan to inspect Unit 2 for similar problems. Regional Action: The resident inspection staff has been observing the licensee's recovery activities in the Unit 1 ice condenser. In addition, the resident inspection staff, accompanied by the regional ice condenser specialist, will also inspect the Unit 2 ice condenser. Contact: R. CARROLL (404)562-4511 _ REGION IV MORNING REPORT PAGE 3 AUGUST 7, 1998 Licensee/Facility: Notification: Washington Public Power Supply System MR Number: 4-98-0048 Washington Nuclear 2 Date: 08/06/98 Richland,Washington Call from SRI to Regional office Dockets: 50-397 BWR/GE-5 Subject: LOSS OF DIVISION II 4160V BUS DURING DIVISION II EDG TROUBLESHOOTING Discussion: At 2:52 p.m. PDT, on August 5, Washington Nuclear Project-2 (WNP-2) experienced a loss of the Division II 4160V vital bus (SM-8) during troubleshooting on the voltage regulator of the Division II emergency diesel generator (EDG). Subsequent reenergization of Bus SM-8 caused an unexpected trip of the reactor feedwater Pump B turbine. Plant systems responded appropriately to the loss of the feedwater pump and power was stabilized at 68 percent. During the monthly surveillance of the Division II EDG, while loaded to approximately 3300 kW and 0.5 MVARS, fluctuations were observed in the EDG output amps and VARS. The EDG was secured and the diesel declared inoperable at 10:45 a.m. on August 4. Troubleshooting efforts that evening focused upon the EDG voltage regulator and the motor-operated potentiometer (MOP). Both were tested with the EDG operating and SCR Bridge 1 in service. No abnormalities were identified, with the exception of the Phase A SCR that apparently was not firing properly. In parallel, the licensee completed the TS required actions to verify the availability of offsite power sources and operability of the Division I and III EDGs. The surveillances were completed satisfactorily and all Division I and III redundant equipment is operable. Based upon the identified degradation of the Phase A SCR on Bridge 1, the licensee performed additional troubleshooting on the voltage regulator with SCR Bridge 2 in service. During this stage of the troubleshooting, with the EDG loaded to approximately 3/4 of full load, small swings in generator amps and VARS were seen and data was collected. After some minutes of steady variations, the VARS output suddenly increased to full meter scale (greater than 4 MVARS). Operator attempts to adjust the voltage regulator and reduce the generator VARS output were unsuccessful. In approximately 16 seconds, prior to operators tripping the EDG, the high voltage output of the EDG resulted in a timed overcurrent trip of the Bus SM-3 feeder breaker to Bus SM-8 and a bus lockout. The lockout protection logic opened the EDG feeder breaker and deenergized Bus SM-8. Recognizing that the loss of Bus SM-8 resulted in a loss of standby service water to the unloaded EDG, operators tripped the EDG. SM-8 was deenergized for approximately 8 minutes until operators reset the bus lockout and reenergized SM-8 from the unit backup transformer. The loss of SM-8 resulted in a loss of the Division II keepfill pump and subsequent depressurization of the RHR B and C loops. RHR B and C loops were restored to operable status in about an hour, after the keepfill pump was restored and the loops were filled and vented. The loss of SM-8 also deenergized the reactor protection system (RPS) B motor-generator REGION IV MORNING REPORT PAGE 4 AUGUST 7, 1998 MR Number: 4-98-0048 (cont.) set causing a half-scram on RPS B. RPS B was restored and the half-scram reset within 30 minutes. When SM-8 was reenergized, reactor feedwater Pump B tripped unexpectedly. The licensee determined that the electrical transient from reenergizing Bus SM-8 resulted in a perturbation to the feedwater Pump B electrical overspeed sensing circuit, generating an overspeed trip signal to the feedwater turbine stop valves. The loss of the pump automatically initiated a recirculation system runback to approximately 68 percent power. Reactor feedwater Pump A properly restored and maintained reactor water level. The lowest level on the transient was 19 inches (low water level scram is at 13 inches). Reactor Feedwater Pump B was subsequently returned to service. The licensee has established an incident review board to evaluate the event. The voltage regulator on the Division II EDG has been replaced. The licensee is evaluating the impact of the high voltage output of the EDG on the generator windings and on loads connected to Bus SM-8. The 72-hour action statement for the inoperable Division II EDG expires at 10:45 a.m. PDT, on August 7. Regional Action: The resident inspector will continue to monitor the licensee's investigation of the cause of the event and appropriateness of the plant response. Contact: H. J. Wong (925)975-0296 S. C. Boynton (509)377-2627 _