Headquarters Daily report AUGUST 31, 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 I AUGUST 31, 1994 Licensee/Facility: Notification: Boston Edison Co. MR Number: 1-94-0097 Pilgrim 1 Date: 08/30/94 Plymouth,Massachusetts SRI PC Dockets: 50-293 BWR/GE-3 Subject: REACTOR TRIP DUE TO FULL LOAD REJECT Reportable Event Number: 27720 Discussion: On 8/29, at 7:32 am, a turbine-generator load reject and automatic reactor trip occurred from 100 percent power. Three of the four safety relief valves lifted to minimize the reactor pressure transient as anticipated. Group II and Group VI PCIS signals were also received as expected. Two, in series, clean air supply dampers which are part of the Group II containment isolation, failed to fully close and were subsequently closed manually. The reactor was quickly stabilized at approximately 940 psig and a normal cooldown was initiated. In accordance with the licensee's post-scram off-normal procedure (EOPs on RPV control had been properly entered and exited) and during the subsequent cooldown, two of the three reactor feedwater pumps were secured. Initially the 'B' and 'C' feedwater pumps were stopped but operators locally noticed mechanical failures on the A and C pumps (i.e. a significant oil leak and a failed pump seal, respectively). The operators secured the 'A' feedwater pump when low lube oil pressure alarm came in (contrary to ENS report, the A pump did not trip). The reactor core isolation cooling system was briefly operated to maintain reactor vessel water level until the 'B' feedwater pump could be restarted. The cooldown continued normally and the plant entered the shutdown cooling mode of operation at 10:33 pm on 8/29. The turbine-generator lockout was caused by an unexplained ground that caused a neutral bus overvoltage condition. Prior to the lockout, increasing stator water cooling (SWC) system conductivity was observed. Licensee personnel were investigating the problem and the conductivity had started to trend downward when the automatic scram occurred. The SWC system demineralizer resin had been replaced during a 8/27-28 power reduction. The licensee has assembled a multidisciplined analysis team (MDAT) to investigate the cause of the event and determine root causes for the anomalies encountered prior to restart. Regional Action: The resident inspector was present in the control room at the time of the reactor scram and monitored licensee response to the event and is following the licensee's investigation. Some public and media attention has occurred and the resident inspectors are responding to inquiries. Contact: John MacDonald (508)747-0565 Beth Korona (508)747-0565 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION II AUGUST 31, 1994 Licensee/Facility: Notification: Carolina Power & Light Co. MR Number: 2-94-0078 Robinson 2 Date: 08/31/94 Hartsville,South Carolina Dockets: 50-261 PWR/W-3-LP Subject: MANAGEMENT CHANGES AT H. B. ROBINSON Reportable Event Number: N/A Discussion: Marc Pearson, previously Plant General Manager, has been offered the position of Director of Special Projects with Nuclear Business Operations at CP&L's Corporate Office in Raleigh, N.C. Dale Young, previously Operations Manager at the Callaway Plant, will become the Plant General Manager on September 26, 1994. Until he arrives, Max Herrell will serve as the Acting Plant General Manager. Bruce Meyers, previously at CP&L's Harris Plant, has been named as the Operations Manager. He arrived on site on August 29, 1994. Regional Action: Information only. Contact: J. L. STAREFOS (404)331-5568 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION III AUGUST 31, 1994 Licensee/Facility: Notification: Commonwealth Edison Co. MR Number: 3-94-0154 Quad Cities 2 Date: 08/31/94 Cordova,Illinois Dockets: 50-265 BWR/GE-3 Subject: LOSS OF REACTOR RECIRCULATION COOLANT PUMP Reportable Event Number: N/A Discussion: On August 30, 1994, after observing lower speed on the 2A recirculation pump, an operator was dispatched to lock the scoop tube in place. Immediately after locking scoop tube, the operator reported smoke from either the A motor generator (MG) set control panel or the MG set itself. The 2A MG set field breaker tripped subsequently; the operator reported decreasing smoke and verified the smoke had originated from the control panel. Nuclear engineers were present in the control room at the time of the event. The engineers monitored nuclear instrumentation as the operators inserted rods to below the 80 percent flow control line in order to match pump speed and avoid the region of instability. Subsequent calculations verified that the region of instability was not entered. The suspected cause for the loss of the recirculation pump was a failed resistor in the control circuit which caused the failure of the power transformer. The licensee replaced the failed resistor with two resistors in series with a higher power capacity for each resistor. The modification to the circuitry was completed for both recirculation pumps on Unit 2. The licensee plans to perform the same modification on Unit 1 today. The causal of the failure of the resistor has not yet been determined. Regional Action: The residents will continue to monitor licensee actions. Contact: P.L. HILAND (708)829-9603 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION IV AUGUST 31, 1994 Licensee/Facility: Notification: Pacific Gas & Electric Co. MR Number: 4-94-0087 Diablo Canyon 1 2 Date: 08/31/94 Avila Beach,California Licensee to SRI Dockets: 50-275,50-323 PWR/W-4-LP,PWR/W-4-LP Subject: PERSONNEL CHANGES Reportable Event Number: N/A Discussion: On August 30, 1994, Pacific Gas and Electric (PG&E) announced that, in addition to other reductions of personnel throughout the PG&E system to reduce costs, the Steam Generation Business Unit will reduce personnel by about 700 bargaining unit employees. Although Diablo Canyon is not in the Steam Generation Business Unit, the union employees affected by the personnel cuts in Steam Generation have rights to "bump" Diablo Canyon employees, depending on seniority status. A Diablo Canyon training program has been established for those incoming personnel who must sucessfully complete extensive nuclear training before bumping a Diablo Canyon employee. The disciplines at Diablo Canyon which will probably be affected are Mechanical Maintenance, Electrical Maintenance, and Clerical workers. The implementation of PG&E restructuring and downsizing is just beginning; therefore, the extent of bumping at Diablo Canyon is not yet known, but it is estimated to be less than 100 bargaining unit employees. More specific information as to the number of personnel taking advantage of bumping privileges will be available in early 1995. Regional Action: The resident inspectors are monitoring the effect of this announcement on Diablo Canyon employees. Contact: M. Miller (805)595-2353 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION IV AUGUST 31, 1994 Licensee/Facility: Notification: Arizona Public Service Co. MR Number: 4-94-0088 Palo Verde 3 Date: 08/31/94 Wintersburg,Arizona SRI Dockets: 50-530 PWR/CE80 Subject: REACTOR TRIP ON HIGH STEAM GENERATOR LEVEL Reportable Event Number: 27728 Discussion: On August 30, 1994, at 3 p.m. (MST), the reactor at Palo Verde Unit 3 tripped from 100 percent power due to high water level in Steam Generator 2. The cause of the high level was a failed fuse in the power supply to the master controller for the feedwater control system. A main steam isolation signal was generated from the high water level which closed the main steam isolation valves. One main steam safety valve lifted briefly in response to the initial pressure transient. Subsequently, decay heat was removed by the auxiliary feedwater system and through the atmospheric dump valves. There was no initiation of safety injection systems. The failed fuse for a power supply to the feedwater control system master controller for Main Feedwater Pump 2 caused the level signal for Steam Generator 2 to go to zero, which caused both main feedwater pumps to increase speed. The feedwater economizer valve for Steam Generator 1 operated properly to control level in Steam Generator 1; however, the economizer valve for Steam Generator 2 received an open signal due to the master controller failure. The water level in Steam Generator 2 rose to the high level trip setpoint approximately 22 seconds after both main feedwater pumps increased speed. Due to a startup transformer being out of service for planned maintenance, only two of the four reactor coolant pumps fast-transferred to the bus provided with off-site power (per design). Two reactor coolant pumps maintained forced circulation of the reactor coolant system. Other anomalies being reviewed by the licensee are: inability to start the startup (nonsafety) auxiliary feedwater pump approximately 2 hours after the reactor trip (failed relay), inability to trip Main Feedwater Pump 1 from the control room (possible debris in the trip valve), and tripping of a condensate pump on low flow conditions. Contrary to the 50.72 report, the licensee does not plan to issue a press release. Regional Action: The resident inspectors responded to the control room immediately after the reactor trip and monitored the licensee's response. The inspectors are closely monitoring the licensee's evaluation of the plant response to the reactor trip and the licensee's corrective actions. Contact: H. Wong (510)975-0296 K. Johnston (602)386-3638