ML18095A430

Special Rept 90-10:on 900721,64 & 84 Ft Elevation Switchgear Room CO2 Sys Inoperable for More than 14 Days.Caused by Inadequate Communications,Departmental Interfaces & Accountability.Sys Relay Replaced

ML18095A430
Person / Time
Site:	Salem
Issue date:	08/20/1990
From:	Miller L Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
90-10, NUDOCS 9008270131
Download: ML18095A430 (3)

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• Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038 Salem Generating Station August 20, 1990 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Dear Sir:

SALEM GENERATING STATION LICENSE NO. DPR-75 DOCKET NO. 50-311 UNIT NO. 2 SPECIAL REPORT 90-10 This Special Report addresses the circumstances surrounding the inoperability of the 64' and 84' Elevation Switchgear Rooms C02 Systems for greater than fourteen (14) days . . This report is being submitted in accordance with the requirements of Technical Specification Action Statement 3.7.10.3c.a pursuant to Technical Specification 6.9.2. It is being submitted within thirty (30) days as per the Action Statement ..

Sincerely yours, 1/Ot?d~/o,_-

L. K. Miller ~j -

General Manager -

Salem Operations MJP:pc Distribution 9008270131 906820 c PDR ADOCK 05000311 S PDC The Energy People 95-2189 (10M) 12-89

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UNIT 2 SPECIAL REPORT 9 0 .

PLANT IDENTIFICATION:

Salem Generating Station - Unit 2 Public Service Electric & Gas Company Hancock's Bridge, New Jersey 08038 IDENTIFICATION OF OCCURRENCE:

64' and 84' Elevation Switchgear Rooms C02 Fire Protection Systems Inoperable For Greater Than Fourteen Days Event Date{s): 7/21/90 Report Date: 8/20/90 This report was initiated by Incident Report Nos.90-466 and 90-467.

CONDITIONS PRIOR TO OCCURRENCE:

Mode 4 {Hot Shutdown)

DESCRIPTION OF OCCURRENCE:

This special report describes the inoperability of the automatic actuation capability of the 64' and 84' Elevation Switchgear Ro.oms C02 Fire Protection Systems .for greater than fourteen (14) days.

This report is submitted for informational purposes in accordance with Technical Specification Action Statement 3.7.*10.3c.a which states:

"With one or more of the above required C02 systems inoperable, within one hour establish a continuous.fire watch with backup fire suppression equipment for those .areas in which redundant systems or components could be damaged; for other areas, establish an hourly fire watch patrol. Restore the system to OPERABLE status within 14 days or, in lieu of any other report required by Specification 6.9.1, prepare and submit a Special Report to the Commission pursuant to Specification 6.9.2 within the next 30 days outlining the action taken, the cause of the inoperability and the plans and schedule for restoring the system. to OPERABLE.status.

On July 7, 1990, Technical Specification Action Statement 3.7.10.3c.a was entered due to declaring the 64' and 84' Elevation Switchgear Rooms C02 Fire Protection Systems inoperable. The systems.were

• declared inoperable due to failure of a required surveillance.

operability check. The No. 23 (64' Elevation) and No. 25 .(84' Elevation) Switchgear Exhaust Fans failed to shutdown after actuation of the respective manual C02 suppression system. The fans are required to shutdown to ensure the respective area's C02 level remains at a concentration designed to *mitigate the consequences of a fire.

APPARENT CAUSE OF OCCURRENCE:

The cause of both C02 systems' inoperability has been attributed to equipment failure. The exhaust fans had failed to shutdown due to the failure of their associated time deiay.relay {Agastat, Part No.

7024 AD), which had failed due to normal wear.

The investig~tion info the root cause(s) as to why the repair was not

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UNIT 2 SPECIAL REPORT 9 0 -

• APPA~ENT CAUSE OF OCCURRENCE:

(cont'd) completed within fourteen (14) days is continuing.

• Investigations to date indicate that the causes of the event involve inadequate communications, departmental interfaces and accountability.

ANALYSIS OF OCCURRENCE:

The 64' and 84' Elevation Switchgear Rooms C02 Fire Protection Systems are designed to mitigate the consequences of a fire in their respective areas. They are a manually initiated system. Upon identification of the system failures, a continuous fire watch was implemented as per Technical Specification Action Statement 3.7.10.3c.a. Although the failures would not prevent C02 discharge, a C02 concentration necessary to extinguish a postulated fire may not be achieved or maintained. However, the fire watch assigned would provide early fire warning such that other compensatory actions could be implemented; therefore, this event did not affect the health or safety of the public. This event is reportable to the Nuclear Regulatory Commission in accordance with the requirements of Technical Specification Action Statement 3.7.10.3c.a pursuant to Technical Specification 6.9.2.

CORRECTIVE ACTION:

The 64' Elevation Switchgear Room C02 System relay was replaced and the system declared operable on July 21, 1990 at 1215 hours0.0141 days <br />0.338 hours <br />0.00201 weeks <br />4.623075e-4 months <br /> upon successful completion of i~s surveillance.

The 84' Elevation Switchgear Room C02 System was returned to operable status on July 22, 1990 at 0550 hours0.00637 days <br />0.153 hours <br />9.093915e-4 weeks <br />2.09275e-4 months <br /> upon successful completion of its Surveillance. The failed relay was replaced on July 21, 1990; however, the system failed its operability retest due to no indication of the exhaust systems' damper closure (in the Control Room). Investigation revealed that the damper indication limit switch setting had drifted. The setting was adjusted and upon successful completion of an operability retest, the C02 System was declared operable and Technical Specification Action Statement 3.7 .. 10.3c.a was exited on July 22, 1990 at 0550 hours0.00637 days <br />0.153 hours <br />9.093915e-4 weeks <br />2.09275e-4 months <br />.

The investigation of the circumstances surrounding the failure to repair the C02 systems within fourteen (14) days to determine the root cause(s) and contributing cause(s) to the event is continuing. A supplement to this Special Report will. be** issued upon comple.tion of this investigation. _*~

A structured daily review of all Action Statements in effect, by station managers, has recently been implemented. Had this*. upgraded practice been in place, when the *co2 Systems were inoperable, additional management focus would have, in all probability,* demanded timely action in resolving the problem.

Y ~o-ff-orct'o..-

Gerieral Manager -

• Salem Operations MJP:pc SORC Mtg.90-110