ML12157A286
| ML12157A286 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 06/05/2012 |
| From: | Vincent Gaddy, Uselding L M Division of Nuclear Materials Safety I |
| To: | |
| AMT/V.Gaddy | |
| References | |
| PNO-IV-12-004A | |
| Download: ML12157A286 (2) | |
Text
June 5, 2012 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -- PNO-IV-12-004A This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without verification or evaluation, and is basically all that is known by the Region IV, Arlington, Texas staff on this date.
Facility RIVER BEND STATION St. Francisville, LA 70775 Docket: 50-458 License No. NPF-47 Licensee Emergency Classification Notification of Unusual Event Alert Site Area Emergency General Emergency X Not Applicable
SUBJECT:
UPDATE - AUGMENTED INSPECTION TEAM ONSITE AT RIVER BEND STATION DESCRIPTION:
The preliminary notification supplements information in PNO-IV-12-004, which documented commencement of an Augmented Inspection Team (AIT) assessment of the circumstances surrounding the May 24, 2012, loss of non-safety-related service water and reactor scram at the River Bend Station. An electrical fault associated with a feedwater pump motor caused a loss of circulating water and non-safety-related cooling water which prompted operators to scram the reactor. The fault was not isolated due to a failed relay. Both divisions of safety-related standby service water started and restored cooling to the safety-related loads.
The licensee concluded that an improperly sized and loose lug on a power connection to feedwater pump B precipitated the event. NRC resident inspectors and members of the AIT inspection team monitored licensee activities to restore and repair plant equipment.
The reactor was restarted on June 1, 2012, at 3:23 p.m. Following start-up, the licensee received indications that three safety relief valves were not completely seated. Attempts to re-seat the valves were not successful. On June 2, at 2:41 p.m. the licensee completed a plant shutdown by inserting a manual reactor scram to repair the safety relief valves. The licensee is currently troubleshooting to determine why the safety relief valves did not properly seat. They expect a 5-7 day outage to complete valve repairs.
The state of Louisiana has been informed. This information has been discussed with licensee management and is current as of June 5, 2012, 2:43 p.m. (CDT).
ADAMS ACCESSION NUMBER: ML12157A286 CONTACTS: Lara Uselding Vincent Gaddy (817) 917-0321 (817) 917-1211 Lara.Uselding@nrc.gov Vincent.Gaddy@nrc.gov