ML20058M434

Forwards Response to Violations Noted in Insp Repts 50-369/93-22 & 50-370/93-22.Corrective Actions:Abnormal Procedure AP/2/A/5500/12,loss of Normal Letdown Charging or Seal Injection Flow Procedure Implemented on 930909

ML20058M434
Person / Time
Site:	McGuire, Mcguire
Issue date:	12/09/1993
From:	Mcmeekin T DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9312200325
Download: ML20058M434 (3)

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, Duke 1%urr Company T C Maruus hkGuire Nudear Generation Department Vice President 12700 Hagers Terry Road (MG01A) (704)S75 4800 Hun:ersmile NC28073-8985 t704)S75-4809 F<x DUKE POWER December 9,1993 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk i Washington, D.C. 20555  !

Subject:

McGuire Nuclear Station, Units 1 and 2  :

Docket Nos. 50-369 and 50-370 NRC Inspection Report No. 50-369,370/93-22 Violat;on 50-370/93-22-01 Reply to a Notice of Violation Gentlemen:

Enclosed is the response to the Notice of Violation issued November 9,1993 concerning inadequate abnormal procedure guidance to alert operations personnel to the potential for voiding letdown piping.

Should there be any questions concerning this response, contact Randy Cross at (704) 875-4179.

Very Truly Yours, lll,1%Nl . .

n T. . McMeekin Attachment xc: (w/ attachment)

Mr. S. D. Ebneter Mr. George Maxwell Regional Administrator, Region 11 NRC Senior Resident inspector U.S. Nuclear Regulatory Commission McGuire Nuclear Station -

101 Marietta St., NW, Suite 2900 Atlanta, Georgia 30323 Mr. Victor Nerses U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Ono White Flint North, Mail Stop 9H3 Washington, D. C. 20555 f

9312200325 931209 ADOCK 05000369 o

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, l McGuire Nuclear Station Reply to a Notice of Violation Violation 370/93-22-01

-l Technical Specification 6.8.1 requires that written procedures be established, implemented and maintained 1 ;

covering the applicable procedures recommended in Appendix A of Regulatory Guide 1.33, Revision 2, February 1978 which includes the operation of the letdown charging system. >

l l Contrary to the above, the abnormal operating procedure AP/2/A/5500/12, Loss Of Normal Letdown j Charging or Seal injection Flow procedure, was implemented on September 9,1993, when the unit, while I operating in Mode 3, experienced a loss of letdown flow due to a system isolation valve 2NV-2 going closed 6 no apparent reason. The procedure was inadequate in that it failed to provide any cautions, j instructions or guidance and it failed to require any special controls to alert the operator of the potential J voiding of the letdown piping when 2NV-2 closes. This inadequacy resulted in the formation of an  : .j undetected void in the letdown system when 2NV-2 drifted shut because its valve interlock did not cause the downstream letdown orifice isolation valve 2NV-458 to simultaneously close. Later,2NV-2 was cycled j opened, causing the system to experience a water hammer that contributed to a letdown system leak of about 10-15 gallons per minute to occur inside the containment building.

This is a Severity Level IV (Supplement 1) violation.

Reolv to Violation 370/93-22-01 l

1. Reason for the Violation:

Abnormal operating procedure AP/2/A/5500/12, Loss of Normal Letdown Charging or Seal Injection Flow procedure, did not take into consideration the potential adverse effects of interlock malfunctions associated with the respective NV system isolation valves.

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2. Corrective steps that have been ta_k.en and the results achieved; i

1. AP/1/A/5500/12 and AP/2/A/5500/12, Losc of Normal Letdown Charging or Seal injection Flow procedures, Case 1: Loss of Letdown, were revised on September 24,1993 to reflect the requirement for operators to ensure letdown is isolated by ensuring the three parallel .

flowpath containment isolation valves [1(2) NV-458A,1(2) NV-459A and 1(2) NV-35A]

downstream of reactor coolant letdown isolation valves [1(2) NV-2A and 1(2) NV-1 A] are closed upon indication of loss of letdown flow. In addition, a procedural requirement was established to obtain staff evaluation for potential voiding of the letdown line prior to re-establishing normal letdown except when the emergency procedure set is implemented.

2. An immediate training package was provided to all licensed operators on shift during the period September 12, 1993 through September 26,1993. This package provided a description of the event.

No similar events have occurred since revision of these procedures and completion of the training package review.

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3. Correctiv' e steps that will be taken to avoid further violations:

No additional corrective actions are planned.

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4. Date when full compliance will be achieved:

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McGuire is now in full compliance.

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