05000413/LER-1996-001, Submits Modification to Commitment Contained in LER-96-001

Submits Modification to Commitment Contained in LER-96-001

ML20135D815
Person / Time
Site:	Catawba
Issue date:	12/04/1996
From:	Mccollum W DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9612100154
Download: ML20135D815 (2)

LER-1996-001, Submits Modification to Commitment Contained in LER-96-001

Event date:
Report date:
4131996001R00 - NRC Website

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Catauba Nuclear Generation Department licePraident 4800 ConcordRoad (8031531J200 Oikce York, SC21745 (8W)R31JIMFax DUKEPOWER December 4,1996 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555

Subject:

Catawba Nuclear Station Docket No. 50-413 Change to Commitment - LER 413/96-001 Re:

Planned Corrective Actions numbers 1) and 2)

Gentlemen:

On February 5,1996, Licensee Event Report 413/96-001 was submitted as requ; red by-the facility's license. This report described a forced shutdown of unit 1 to Mode 3 as required by Catawba Unit 1 Technical Specifications 3.3.1 and 3.3.2, when a condition existed during Reactor Trip Breaker testing that challenged the non-safety related Digital Feedwater Control System, Main Feedwater Pump Turbine Speed Control circuit, which runs the Feedwater. Pumps back to minimum speed on a reactor trip. The circuit indicated, by voltage measurement, that a Feedwater Pump runback might occur unnecessarily when the Reactor Trip Breaker being tested was placed back in service.

As a result of the root cause determination,2 planned corrective actions were developed and implemented, relative to monitoring the runback circuit to ensure that the relay is in the correct state prior to retuming to service the Reactor Trip Breaker being tested. These corrective actions were:

1) IP/1/A/3200/02A, IP/1/A/3200/08A, IP/1/A/3200/02B, IP/1/A/3200/08B, IP/2/A/3200/02A, IP/2/A/3200/08A, IP/2/A/3200/02B, and IP/2/A/3200/08B will be changed to provide for procedure completion if indicated voltage is less than or equal to 35 volts, without requiring an engineering evaluation.

2) Engineering will evaluate feasibility of providing procedural and process k}9 guidance for reactor trip breaker restoration to operable and procedure completion for cases where indicated voltage exceeded 35 volts.

O Subsequent to the implementation of these corrective actions, Site Engineering 4

developed, approved, and implemented minor modification CNCE-61214 to the non-safety related runback circuit for unit 1. In addition, minor modification CNCE-61215 was approved for implementation on unit 2 at a future date. The modification changes the 9612100154 961204 PDR ADOCK 05000413 8

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• Document Control Desk P' age 2 December 4,1996 logic required to initiate the runback. This change to the logic improves the reliability of and reduces the challenges to the runback circuit.

As a result of the modification, it is no longer necessary to perform the procedural steps developed in response to the planned corrective actions of LER 413/96-001 applicable to monitoring the state of the circuit's relay during Reactor Trip Breaker testing. Based on the modification's capability to prevent recurrence of the event as described in the subject LER, this letter documents the intent to revise the applicable unit 1 procedures to delete those steps that provide for voltage measurement as a means of determining the state of the runback relay. It is intended that unit 2 will continue to operate in accordance with the commitments made in the subject LER until such time that the approved modification to its circuit is implemented. Following imp lamentation, the applicable unit 2 procedures will be revised to reflect the modification.

4 Cordially,

)

W. R. McCollum, Jr.

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cc:

Mr. S.D. Ebneter INPO Records Center Administrator, Region ll 700 Galleria Place U.S. Nuclear Regulatory Commission Atlanta, GA 30339-5957 l

101 Marietta St., NW, Suite 2900 Atlanta, GA 30323 Mr. P. S. Tam Marsh & McLennan Nuclear U.S. Nuclear Regulatory Commission John Hoffman Office of Nuclear Reactor Regulation 301 Tresser Blvd.

Washington, D.C. 20555 Stamford, CT 06904 Mr. R. J. Freudenberger NRC Resident inspector Catawba Nuclear Station