ML20248F357

Interim Significant Deficiency Rept SDR-L2-89-17 Re Unavailability of Feedwater Maint Isolation Valve to Support RCIC Operation in Event of App R Fire.Initially Reported on 890303.Cause Under Investigation.Rept to Be Submitted

ML20248F357
Person / Time
Site:	Limerick
Issue date:	04/03/1989
From:	PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Russell W NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
SDR-L2-89-17, NUDOCS 8904130041
Download: ML20248F357 (5)

Text

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... o PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET P.O. BOX 8699 PHILADELPHIA A, PA.19101 (2151 e4140oo NUCLE A R ENGINEERING DEPA RTMENT 10CF50.55(e)

AprI1 3, 1989 Mr. W. T. Russell, Administrator Docket No. 50-353 U. S. Nuclear Regulatory Cmmission CPPR-107 Attn: Docunent Control Clerk Mall Station P1-137 Washington, DC 20555

Subject:

Limerick Generating Station - Unit 2 Interim Significant Deficiency Report Unavailability of the Feedwater Maintenance Isolation Valve to Support i RCIC Operation in the Event of an Appendix R i.re.

Reference:

1) Telecon of PECo to NRC dated March 3, 1989

2) Letter frcin to S. J. Kowalski, PECo, to W. T. Russell, NRC entitled "Significant Deficiency Report NO. 249-2 Interim Report for the Nonavilability of Safe Shutdown Capabilities from Outside the Control Room in the Event of a Fire" dated November 4, 1988 I

File: QUAL 2-10-2 (SDR-L2-89-17) l

Dear Mr. Russell:

As cmmitted to In reference 1 above, we are submitting the attached interim Significant Deficiency Report which provides a description of the subject concern and a status report of our completed and ongoing activities.

As part of a self-assessment, PECo is performing a root cause evaluation of all suspected deficiencies with the LGS safe shutdown analysis as conmitted to in the LGS Fire Protection Evaluation Report (FPER). -The results of this assessment should reveal if these i nonconformances are programmatic errors or Isolated deficiencies. I Based on this assessment, corrective actions to prevent recurrence will  !

be Identified. This study should be ccmplete by April 14, 1989, where l upon PECo shall provide a response discussing the rescits of this  !

assessment and the proposed corrective actions In a supplement to SDR l No. 249-2 (reference 2) by May 31, 1989.

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8904130041 890403 y$* 7 PDR ADOCK 05000353 '

S PDC ,

Mr. W. T. Russell,. Administrator April 3, 1989 Page Two If you have any further questions at this time, please contact us.

Sincerely,

/ Y GBH/kh/03298903 Attachment Copy to: W. T. Russell, USNRC, Region 1 Administrator R. A. Grartm, USNRC, LGS 2 Senior Resident Inspector R. J. Clark, USNRC, LGS 2 Project Manager l

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-NUCLEAR ENGINEERING ENGINEERING DIVISION N2-1, 2301 Market. Street' INTERIM SIGNIFICANT DEFICIENCY REPORT SDR NO. L2-89-17 UNAVAILABILITY OF THE FEEDWATER MAINTENANCE ISOLATION VALVE TO SUPPORT RCIC OPERATION IN THE EVENT OF AN APPENDIX R FIRE NRC CONSTRUCTION PERMIT NO. CPPR-107 DESCRIPTION OF DEFICIENCY During a walkdown.of Limerick Generating Station Unit 2 as part of the startup program, PECo personnel identified a condition that could adversely affect the ability of the plant to safely' shut down in the event of an Appendix R fire.

This condition involves a control cable (2CB22314E) associated with the Feedwater (FW) system maintenance Isolation valve (HV-41-2F0118) which could be adversely affected by a postulated fire in the Unit 2 Cable Spreading Room (Fire Area 23) and the Main Control Room (Fire Area 24). l This. valve is a normally open, motor-operated, remote manual.

Isolation valve located inside primary containment. The valve, when closed, Isolates the 'B' loop of the FW system for maintenance

-purposes. The control cable for this valve was not considered necessary. to support Shutdown Method R, and therefore, was not protected from fire damage in Fire Areas 23 and 24. In the event .i of a fire in these areas,. an electrical short resulting from fire-induced damage to the valve control cable could cause the valve to close. The RCIC system uses the FW system as a flow path for injection into the reactor vessel. RCIC flow is discharged into the

'B' loop of the FW system upstream of valve HV-41-2F011B. Inadvertent closure of this valve due to a fire in Fire Areas 23 and 24 would Isolate the flow path for RCIC system injection into the reactor L vessel, thereby rendering RCIC unavailable for accomplishing safe shutdown.

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SAFETY IMPLICATIONS l'

The postulated Appendix R Fire could affect the operation of  ;

. Shutdown Method R. The condition could adversely impact the l ability of the RCIC system to support safe shutdown in Fire Areas 23 and 24.

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p Fire damage could cause the FW system maintenance isolation valve to close. This would isolate the flow path for RCIC systan injection into the reactor vessel, thereby rendering RCIC unavailable to accomplish safe shutdown. It is concluded that this deficiency, remaining undetected, could have affected the safe operation of the plant.

The proxinete cause of this condition is personnel error committed during the original SSD Analysis. The condition affecting the FW systen maintenance isolation valve was caused by a failure to properly identify and protect essential cables for safe shutdown canponents and systems. The FW system maintenance isolation valve in the 'B' loop of the FW system must remain in its normally open position during a fire for which Shutdown Method R is being relied upon to shut down the plant so that the flow path for RCIC system injection into the reactor vessel is available. The need to protect the control cable for valve HV-41-2F011B from damege due to a fire for which Shutdown Method R would be relled upon was not considered since this valve is in the FW systen, and therefore, was not considered essential to support safe shutdown.

Corrective Actions In accordance with the PECo Deportability Evaluation Process, a deportability evaluation was initiated. On March 3,1989, the condition was reported to the NRC as a 10C.t',50.55(e) reportable condition. The  ;

This condition required  ;

scope of this deficiency also includes Unit 1.

prompt notification on February 15, 1989 which was folloaed by LER 89-012 on March 14, 1989.

The appropriate correct ive actions to prevent recurrence are being evaluated. The necessary actions will be identified and a schedule for completion of these actions will be provided in a supplement to SDR No.

249-2 Creference 2) by May 31, 1989.

General Plant procedure, GP-2, "Nornal Plant Startup", will be revised to require that the thennal negnetic circuit breaker in motor control center 20B223 be administratively controlled to ensure it is open except when the reactor is in a cold shutdown condition. This would ensure that fire-caused danege to the valve's control cable cannot result in inadvertent energization of the motor operator.

It is acceptable for the breaker to the motor operator on valve HV-41-2F011B to be open during reactor operation because the valve does not need to close for the purpose of supporting reactor operation or accident mitigation functions. The only purpose of the valve is to allow the feedwater loop to be isolated so that nelntenance activities can be perfonned vhile the reactor is shut down. Under such circtnstances, anple tine is available for the plant operators to close the circuit breaker if needed.

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ll .- Actions to Prevent Recurrence PECo is performing an assessment of the LGS Safe Shutdown (SSD) analysis to determine the root cause of recent LERs written against the SSD capabilities as conmitted to in the LGS FPER. The results of the assessment will identify if the non-conformances in the LERs are programmatic errors or Isolated deficiencies. The study should be completed by April 14, 1989, whereupon PEco shall provide a response discussing the results of this assessment and.the proposed corrective actions in a supplement to SDR No. 249-2 (reference 2) by May 31, 1989.

GBH/esb/03288901

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