ONS-2014-002, Special Report Per Technical Specification 5.6.6, Problem Investigation Process No. O-13-14447

Special Report Per Technical Specification 5.6.6, Problem Investigation Process No. O-13-14447

ML14016A345
Person / Time
Site:	Oconee
Issue date:	01/16/2014
From:	Batson S Duke Energy Corp
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
ONS-2014-002
Download: ML14016A345 (3)

Text

Scott L.Batson DUKE Vice President ENERGY, Oconee Nuclear Station Duke Energy ONOIVP 17800 Rochester Hwy Seneca, SC 29672 ONS-2014-002 o: 864.873.3274 f 864.873. 4208 January 16, 2014 Scott.Batson@duke-energy com ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Duke Energy Carolinas, LLC (Duke Energy)

Oconee Nuclear Station (ONS), Unit No.1 Docket Nos. 50-269 Renewed License No DPR-38 Special Report per Technical Specification 5.6.6 Problem Investigation Process No.: 0-13-14447 Pursuant to ONS Technical Specification 3.3.8, Condition B and Technical Specification 5.6.6, enclosed is a special report regarding the inoperability of a Unit 1, Post Accident Monitoring System, Containment Sump Water Level - Wide Range Instrument. The Channel A instrument was discovered out of tolerance during testing.

This Special Report is being submitted due to Channel A being inoperable for greater than 30 days. The information required by this Special Report is enclosed.

There are no regulatory commitments contained in this report. Any questions regarding the content of this report should be directed to Corey Gray, Oconee Regulatory Affairs at 864-873-6325.

Sincerely, Scott L. Batson Vice President Oconee Nuclear Station Enclosure C)

Document Control Desk January 16, 2014 Page 2 cc:

Mr. Victor McCree, Regional Administrator U.S. Nuclear Regulatory Commission - Region II Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, Georgia 30303-1257 Mr. Richard Guzman, Project Manager (ONS)

(by electronic mail only)

U.S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop O-8C2 Rockville, MD 20852 Mr. Eddy Crowe NRC Senior Resident Inspector Oconee Nuclear Station

ENCLOSURE OCONEE NUCLEAR STATION, UNIT 1 Special Report Per Technical Specification 5.6.6 Description of Condition On December 4, 2013, during performance of Instrument Channel Checks, Channel A of the wide range, Containment Sump Water Level Instrument was determined to be inoperable due to being out of tolerance. This is a Post Accident Monitoring (PAM) Instrument required by Technical Specification 3.3.8. Troubleshooting determined that there may be an intermittent connection failure between the electronic transmitter in the cable room and the transducer in the reactor building. Instrument response was restored, however the channel is considered inoperable because post maintenance testing could not be completed on the transducer, which is located inside containment and is inaccessible during plant operation. The redundant Channel B of the wide range Containment Sump Water Level Instrument remains operable.

Background

The primary purpose of PAM instrumentation is to display unit variables that provide information required by the control room operators during accident situations. The OPERABILITY of the PAM instrumentation ensures that there is sufficient information available on selected unit parameters to monitor and to assess unit status and behavior following an accident.

The availability of PAM Instrumentation is important so that responses to plant corrective actions can be observed, and so that the need for and magnitude of further actions can be determined. The PAM instruments are identified by the ONS specific Regulatory Guide 1.97 analysis, Updated Final Safety Analysis Report (UFSAR), Section 7.5 and the NRC's Safety Evaluation Report for the ONS Regulatory Guide 1.97 analysis which address the recommendations of Regulatory Guide 1.97, as required by Supplement 1 to NUREG-0737.

Containment Sump Water Level Wide Range indication is a Type B, Category 1 variable provided for verification and long term surveillance of Reactor Coolant System (RCS) integrity.

This instrumentation consists of two channels with readout on two indicators and one recorder.

Cause of Inoperability The apparent cause of the inoperability is an intermittent failure in the connection between the electronic transmitter (in the cable room) and the transducer (located inside containment). The Channel A indication could not be returned to service within 30 days because the transducer was not safely accessible while the plant is in operation.

Preplanned Alternate Method of Monitoring Both channels of the Containment Emergency Sump Water Narrow Range Level, and the Borated Water Storage Tank level instruments, remain operable. These instruments provide redundant/diverse indications of RCS integrity during an accident and are Regulatory Guide 1.97 instruments.

Plans and Schedule for Restoring Operability Channel A of Containment Sump Water Level Wide Range is planned to be restored as opportunity allows and no later than the next scheduled Unit 1 refueling outage.

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