Headquarters Daily Report APRIL 03, 1996 *************************************************************************** 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 - REGION I APRIL 3, 1996 Licensee/Facility: Notification: New York Power Authority MR Number: 1-96-0032 Indian Point 3 Date: 04/03/96 Buchanan,New York SRI CALL Dockets: 50-286 PWR/W-4-LP Subject: MANUAL REACTOR TRIP DUE TO HIGH GENERATOR STATOR TEMPERATURE Discussion: On April 2, 1996, at 4:13 pm, NYPA manually initiated a reactor and main turbine generator (MTG) trip due to high MTG stator hydrogen gas differential temperature. At the time of the trip, reactor power was approximately 13 percent with the MTG synchronized to the electrical grid about 1 1/2 hours earlier. The plant was restarted on March 29, 1996, after an extended forced outage which began in mid-September 1995. Operators responded well to the reactor trip and all safeguards equipment functioned as required. Investigation by NYPA has determined that the high stator differential temperature was attributed to inadequate venting of one of the four MTG hydrogen coolers (cooler no. 33). After the trip, operations vented the service water side of the cooler and excessive gas (largely composed of air versus pure hydrogen) was noted. Gas binding of this cooler would result in higher hydrogen temperature returning to the stator coils and result in an excessive differential temperature. A previous problem with MTG hydrogen coolers resulted in a reactor trip in September 1995. Gas binding was also the cause and was attributed to cooler tube leakage on the no. 32 cooler which allowed excess hydrogen to enter the service water side of the cooler. This leakage occurred when hydrogen was being added to the MTG, an evolution which was also ongoing during the April 2 event. NYPA inspected and sleeved all four of the coolers to address this problem. NYPA continues to investigate similarities between the September 1995 trip and the April 2 event as well as implement corrective actions to prevent a recurrence of the problem. Regional Action: Region I was observing plant activities on an around-the-clock basis at the time of the trip. Around-the-clock inspection coverage will continue. Contact: Richard Barkley (610)337-5065 Timothy Frye (914)739-8565 _ REGION IV MORNING REPORT PAGE 2 APRIL 3, 1996 Licensee/Facility: Notification: Entergy Operations, Inc. MR Number: 4-96-0031 Grand Gulf 1 Date: 03/27/96 Port Gibson,Mississippi Dockets: 50-416 BWR/GE-6 Subject: POSSIBLE STRIKE OF CONTRACT SECURITY FORCE Discussion: On March 27, 1996, the licensee notified Region IV that their contract security force had rejected the final Union negotiation offer. The present contract will expire at midnight on April 6, 1996. The Contractor (Wackenhut) has developed a Strike Contingency Plan which addresses such items as training and qualifying replacement personnel and activation of the strike plan. The licensee stated that negotiations are continuing in order to resolve the contract issues. Currently, picket lines are not anticipated to affect the access to the plant by other personnel. The licensee will keep the Region informed as to the results of these negotiations. Regional Action: The Region will continue to monitor the Union negotiations. If the strike occurs, a security inspector will be dispatched to the site to observe the security program. Contact: Blaine Murray (817)860-8126 _ REGION IV MORNING REPORT PAGE 3 APRIL 3, 1996 Licensee/Facility: Notification: Nebraska Public Power District MR Number: 4-96-0032 Cooper 1 Date: 04/03/96 Brownville,Nebraska Resident Inspector Dockets: 50-298 BWR/GE-4 Subject: FUEL LEAK Discussion: On March 29, 1996, the licensee noted elevated activity in the offgas radiation monitor and confirmed a fuel leak by means of reactor coolant system (RCS) sampling. Another RCS sample taken on April 2 showed a marked increase in activity and the presence of Neptunium, a fission product indicative of fuel/coolant interaction. At approximately 7 p.m. (CST) on April 2, the licensee began to downpower in preparation for power suppression testing. At approximately 2:30 a.m. on April 3, operators entered a special procedure and began power suppression testing per guidance in General Electric (GE) SIL 379, Revision 1. Power suppression testing consists of sequential insertion of control rods while monitoring changes in offgas activity to locate failed fuel assemblies. The current core consists solely of GE 9B fuel. As of 7 a.m. on April 3, reactor power was at 57 percent power, and dose equivalent iodine as sampled in the RCS was 4.3 x 10-3 micro-Ci/gm. An administrative limit of 0.2 micro-Ci/gm iodine equivalent, consistent with Standard Technical Specifications, has been imposed by the licensee. General Electric, the fuel supplier, has sent a representative to the site, and contractor personnel specializing in monitoring offgas activity are expected to arrive today. Regional Action: The resident inspectors are monitoring the licensee's actions. Contact: Mary H. Miller (402)825-3371 T. Reis (817)860-8185 _ REGION IV MORNING REPORT PAGE 4 APRIL 3, 1996 Licensee/Facility: Notification: Union Electric Co. MR Number: 4-96-0033 Callaway 1 Date: 04/03/96 Fulton,Missouri SRI OBSERVATION ON SITE Dockets: 50-483 PWR/W-4-LP Subject: MANUAL REACTOR TRIP Reportable Event Number: 30221 Discussion: A manual reactor trip was initiated from 100 percent power on April 2, 1996, at 10:45 a.m. (CST) when the main feedwater isolation valve to Steam Generator B closed. All equipment responded as required except as noted below. Upon energizing the source range detectors, the high voltage power supply for Channel N32 failed high. When the fuses were removed to remove the high voltage from the N32 detector, a flux doubling actuation signal was generated as a result of the fuses being removed. The charging pump suction shifted from the VCT to the RWST as designed. After verifying that an actual flux doubling condition had not occurred, the signal was blocked, the actuation signal was reset, and the charging pump suction was restored to the VCT. The feedwater isolation valve closure was caused by a blown fuse in the valve actuation circuitry. The blown fuse deenergized a solenoid valve that allowed hydraulic fluid to be supplied to the valve actuator piston to close the valve. A specific cause for the fuse failure could not be determined, and the fuse was sent to an offsite laboratory for failure analysis. Because of the rapid feedwater isolation valve closure with main feedwater pumps operating, a water hammer occurred in the feedwater and condensate system. As a result, low pressure feedwater Heaters 3A and 4A sustained leaks at the manway covers and were manually isolated. The heater leaks were subsequently repaired. The fuses for all of the feedwater isolation valves were replaced with new fuses. The high voltage power supply for the N32 source range channel was repaired. The reactor was taken critical at 1:23 a.m. on April 3, and the main generator was synchronized to the grid at 5:43 a.m. on April 3. Regional Action: The Resident Inspectors are monitoring the licensee's activities. Contact: David Passehl (573)676-3181 _