United States Nuclear Regulatory Commission - Protecting People and the Environment

Morning Report for January 8, 2004

Headquarters Daily Report

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REGION II

OCONEE RCS LEAKAGE

Licensee/Facility:

DUKE ENERGY CORP.
Oconee 1
CHARLOTTE, North Carolina
Dockets: 05000269
[1] B&W-L-LP
License No:
Notification:

MR Number: 2-2004-0001
Date: 01/02/2004

Discussion:

This Morning Report updates the 10 CFR 50.72 notification dated January 2, 2004, regarding RCS leakage on Unit 1 and the corresponding Notification of Unusual Event. On January 2 at 8:38 p.m. (EST), Unit 1 control room operators observed and quantified an unidentified RCS leakage of approximately 14 gpm. At the time of the event, the plant was in Mode 3, starting up following a refueling outage. The licensee entered their emergency plan and declared a Notification of Unusual Event based on RCS leakage greater than 10 gpm. The RCS leak was stopped approximately 47 minutes later when control room operators closed a pressurizer sample isolation valve. The licensee identified that the leak source was a relief valve on the pressurizer sample line in containment.

During normal opertions, the relief valve is isolated, but is subject to RCS pressure during pressurizer sampling activities. At the time of the RCS leakage, a pressurizer sample was being taken. The licensee removed the valve and conducted bench testing which showed that it lifted prematurely at a pressure below its design set point. The relief valve was not worked on during the refueling outage. The licensee continues to investigate the event.

Regional Action: The resident inspectors are monitoring the licensee's investigation of the event and independently reviewing the relief valve's maintenance history (including similar applications) and other relevent plant changes completed during the recent refueling outage.

Accession Numbers:

Accession No Accession Date
ML040080914 01/08/2004

Contacts:

Name Office Abbrev Phone No E-Mail
HAAG, ROBERT C R2 (404) 562-4550 RCH@nrc.gov
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