United States Nuclear Regulatory Commission - Protecting People and the Environment

Morning Report for January 23, 2004

Headquarters Daily Report

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REGION II

HYDROGEN GAS IN CATAWBA UNIT 1 COMMON CHARGING PUMP SUCTION HEADER

Licensee/Facility:

DUKE ENERGY CORP.
Catawba 1
CHARLOTTE, North Carolina
Dockets: 05000413
[1] W-4-LP
License No:
Notification:

MR Number: 2-2004-0002
Date: 01/19/2004

Call from Licensee

Discussion:

(This is an update to Licensee Event Notification 40451) - On January 15, 2004, due to a build up of hydrogen gas in the piping near high point vent valve 1ND-28 (A Train "piggy back" isolation/supply valve), the A Train of the Unit 1 Emergency Core Cooling System (ECCS) was declared inoperable and the associated 72-hour Technical Specification (TS) Limiting Condition for Operation (LCO) was entered at 6:57 p.m.. Based on the licensee's belief that the gas intrusion was a discrete event, the LCO was exited on January 18, 2004; but, was re-entered on January 19, 2004, at 7:15 a.m., when ultrasonic testing (UT) revealed that an excessive amount of hydrogen gas had re-appeared. This LCO was exited on January 22, 2004, after the licensee completed an "operable but degraded" determination based on the establishment of compensatory measures to assure the system remains within existing analysis. These compensatory measures included: UT at various locations every 2 hours; establishing venting locations/criteria; establishing/maintaining a Volume Control Tank pressure band; and placing an "Administrative Hold" on associated performance tests until they can be evaluated for potential system impact.

The licensee is continuing its investigation to determine the gas generation rate, the source of the gas, and the types of evolutions which may worsen the situation.

Region II Action:

On January 21, 2004, a region-based inspector with ECCS gas accumulation experience reported on-site to assist in the evaluation of the licensee's problem identification and corrective action activities. The residents will continue to followup on the licensee's activities until the degraded condition is no longer applicable.

Accession Numbers:

Accession No Accession Date
ML040230312 01/23/2004

Contacts:

Name Office Abbrev Phone No E-Mail
CARROLL, ROBERT E R2 (404) 562-4511 REC1@nrc.gov
Page Last Reviewed/Updated Thursday, March 29, 2012