ML022620624
| ML022620624 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 09/19/2002 |
| From: | Ron Kopriva NRC Region 4 |
| To: | |
| References | |
| 39200 MR-IV-02-0002 | |
| Download: ML022620624 (3) | |
Text
PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION IV SEPTEMBER 19, 2002 Licensee/Facility: Notification:
Entergy Operations, Inc. MR Number: 4-02-0002 River Bend 1 Date: 09/19/02 St Francisville,Louisiana Licensee to SRI on 9/18 Dockets: 50-458 BWR/GE-6
Subject:
REACTOR SCRAM Reportable Event Number: 39200 Discussion:
At approximately 8:24 p.m. on September 18, 2002, the River Bend Station scrammed from 100 percent reactor power due to a high average power range monitor flux trip. All control rods fully inserted in the core. The cause of the reactor trip is currently under investigation. Preliminary evidence indicates that a failure of the electrohydraulic control system, resulting in rapid cycling of the turbine generator bypass valves, may have been the cause for the high power scram.
Following the scram, both steam jet air ejector condensers experienced gasket failures on the end bells of the condensers, and all reactor feed pumps tripped on low suction pressure.
Operators responded to the condensate system gasket failure by securing all condensate pumps and manually isolating the steam jet air ejector condensers. With the loss of condensate to the reactor vessel, operators manually initiated the reactor core isolation cooling system to maintain the appropriate reactor level and remove decay heat.
Upon securing the condensate pumps, the control rod drive pumps automatically aligned suction to the condensate storage tank. Following this transfer, alarms in the control room indicated high differential pressure conditions on the control rod drive pumps suction and discharge filters. Operators bypassed the filters and were able to regain flow. The licensee currently believes the high differential pressure condition was a result of particulate in the condensate storage tank being collected in the control rod drive system filters.
The licensee currently believes the transient causing the steam jet air ejector condenser gasket failure and loss of feed pump suction pressure were both initiated as a result of an inadvertent closure of the condensate full flow filter bypass valve following the scram.
Using the reactor core isolation cooling system and the control rod drive pumps, the operators have continued to maintain the reactor in a stable hot standby condition.
The licensee continues to investigate the cause of the reactor trip, the failure of the steam jet air ejector condienser gaskets, and the inadvertent closure of the condensate full flow filter bypass valve.
Regional Action:
In response to this event, NRC resident inspectors responded to the licensees control room.
They continue to monitor licensee activities.
Contact:
R. Kopriva (817)860-8104 P. Alter(225)635-3193