Morning Report for March 11, 1999
Headquarters Daily Report MARCH 11, 1999 *************************************************************************** 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 MARCH 11, 1999 Licensee/Facility: Notification: Public Service Electric & Gas Co. MR Number: 1-99-0010 Hope Creek 1 Date: 03/11/99 Hancocks Bridge,New Jersey SRI PC Dockets: 50-354 BWR/GE-4 Subject: CONTROL ROD BLADE BLISTER AT HOPE CREEK Discussion: During a planned refueling outage visual inspection, Public Service and Electric Gas Company (PSEG) identified a blister on an ABB (Asea Brown Boveri) Model CR82 control rod blade. The blistered control rod was the center control rod and had been fully inserted and disarmed for approximately the last ten months of Hope Creek's operating cycle. The control rod had been fully inserted into the core in March 1998 after difficulty in withdrawing the control rod for a rod pattern adjustment. Hope Creek is replacing the blistered control rod blade and continuing blade inspections. An ABB vendor representative was present during the visual inspections and ABB is evaluating the cause and significance of the CRB blister in accordance with 10 CFR 21. Regional Action: None. Contact: G. Meyer (610)337-5211 D. Orr (609)935-3850 _ REGION IV MORNING REPORT PAGE 2 MARCH 11, 1999 Licensee/Facility: Notification: Arizona Public Service Co. MR Number: 4-99-0010 Palo Verde 1 Date: 03/11/99 Wintersburg,Arizona From SRI Dockets: 50-528 PWR/CE80 Subject: AUTOMATIC REACTOR TRIP IN UNIT 1 (EVENT 35456) Discussion: On March 10, 1999, at 1:26 p.m. MST, Palo Verde Unit 1 experienced an automatic reactor trip as the result of high pressurizer pressure. Prior to the trip, the throttle pressure limiter circuit in the electrohydraulic control system failed, causing two turbine control valves to close. Consequently, the steam bypass system valves opened to control pressure in the main steam lines. The operations staff, believing the bypass valve control circuitry had experienced a fault and opened inadvertently, incorrectly placed the bypass valve control switch in the emergency off position to close the valves. Closing the valves caused main steam header pressure to increase, which caused two main steam safety valves to lift and resulted in a corresponding increase in primary system pressure. Due to the mismatch between reactor power and secondary system demand, the pressurizer pressure high setpoint was reached and there was an automatic reactor trip. Following the reactor trip, a postevent review indicated that two main steam safety valves may have prematurely lifted. The licensee is continuing to investigate whether the lifts were premature. At approximately 2:29 p.m. MST, a main steam isolation system signal occurred due to a high water level in Steam Generator 2. The high water level condition occurred when the operations staff attempted to place the steam generator level control system in automatic to maintain level. After initiating automatic control, a failure in the level control circuitry resulted in the level increasing. The operator took manual control and closed all main feedwater isolation valves. Since a large volume of relatively cold water had been placed in the steam generator before feedwater was isolated, when this water heated up, it caused a main steam isolation signal to be generated on a high level. In response, the operations staff started the emergency feedwater system and removed decay heat by the use of the secondary system atmospheric dump valves. The licensee has repaired the equipment anomalies identified with the throttle pressure limiter circuit and the steam generator level control system. The unit is currently in Mode 3, with an anticipated return to power operations on March 12, 1999. Regional Action: Routine followup by the resident staff is ongoing. Contact: Jim Moorman (602)386-3638 Phil Harrell (817)860-8250 _
Page Last Reviewed/Updated Wednesday, March 24, 2021
Page Last Reviewed/Updated Wednesday, March 24, 2021