ML14205A198
ML14205A198 | |
Person / Time | |
---|---|
Site: | Summer |
Issue date: | 07/24/2014 |
From: | Mark King, Reece J E NRC/RGN-II/DRP/RPB5 |
To: | |
References | |
PNO-II-14-005A | |
Download: ML14205A198 (1) | |
Text
July 24, 2014 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE - PNO-II-14-005A This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. Some of the information may not yet be fully verified or evaluated by the Region II staff (Atlanta, GA)
Facility Licensee Emergency Classification South Carolina Electric & Gas (SCE&G) V.C. Summer, Unit 1 Columbia, SC Docket: 50-395 Notification of Unusual Event Alert Site Area Emergency General Emergency
_X_ Not Applicable
SUBJECT:
UPDATE- SHUTDOWN GREATER THAN 72 HOURS DUE TO LEAKING PRESSURIZER SAFETY VALVE On July 13, 2014, staff at the V.C. Summer Nuclear Station (VCSNS), Unit 1 suspected that a pressurizer safety valve was leaking and made a conservative decision to shutdown the unit. On July 17, the vendor notified the licensee that pressurizer safety valve test results showed the valve was not leaking. The licensee subsequently identified that the source of the leak was a reactor vessel head vent valve and repaired the valve.
The NRC resident inspectors were promptly notified and were onsite to monitor the shutdown and activities to identify and repair the leak. The resident inspectors are also monitoring the licensee's additional reviews into the valve failure.
While returning the unit to service on July 22, the plant automatically tripped due to decreasing water level in the steam generators. The reactor trip occurred when the condensate polishing system bypass valve failed to open as required and feedwater flow was reduced. All safety systems responded as designed. The NRC resident inspectors were promptly notified and responded to the site to assess the plant and monitor the licensee's ac tions. The licensee has completed repairs to the condensate valve and the plant is currently being returned to service.
This preliminary notification is issued for information. The State of South Carolina has been notified by the NRC.
Region II received initial notification of this occurrence by the NRC Resident Inspectors who have been monitoring licensee actions. The information presented herein has been discussed with the licensee and is current as of 8:00 a.m. on July 24, 2014.
ADAMS Accession Number: ML14205A198 Contact: Michael F. King Jim Reece (404) 997-4511 (803)345-5683 Michael.King2@nrc.gov James.Reece@nrc.gov