ML20086K575

AO 74-56:on 741218,RCIC Inverter on Panel 20C19 Failed. Caused by Component Failure.Inverter Replaced & Returned to Svc

ML20086K575
Person / Time
Site:	Peach Bottom
Issue date:	12/28/1974
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20086K578	List: ML20086K575 ML20086K581
References
AO-74-56, NUDOCS 8401270287
Download: ML20086K575 (2)

Text

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Mr. A. Giambusso 'Q. _

Deputy Director of R; actor Projects Uni ted States Atomic Energy Commission

- Directorate of Licensing Washington, D.C. 20545.

Subject:

Abnormal Occurrence The following occurrence was reported to Mr. Walt Baunack, i A.E.C. Region 1 Regulatory Operations Office on December 18, 1974.

Wri tten noti fication was made to Mr. James P. O'Reilly, Region 1 Regulatory Operations Office on December 18,-1974. In accordance with ,

Section 6.7.2.A of the Technical Specifications, Appendix A of DPR 44 for Uni t 2 ' Peach Bottom Atomic Power Station,- the following report is being submitted to the Directorate of Licensing as an Abnormal Occurrence:-

Re ference: License Number DPR-44 Technical Speci fication

Reference:

3 5.D Report No.: 50-277-74-56 Report.Date: December 28, 1974-Occurrence Date: December 18, 1974 Faci li ty: Peach Dottom Atomic Power. Station R.D. #1, Delta, Pennsylvania 17314 Identi fication of Occurrence:

Failure of RCIC Inverter on 20C19 panel.

Condi tions Prior to Occurrence:

Uni t 2 operating at 95% power.

c Description of Occurrence:

During steady-state plant operation, the RCIC Inverter on

; panel 20C19 tripped for no apparent reason.

g Designation of Apparent Cause of Occurrence: )

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Component failure wi thin the RCIC inverter. - ff an -

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Mr. A. Giambusso December 28, 1974 Q Page 2 t

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Analysis of Occurrence:

At the time of the inverte- tripping, all other Unit 2 Emergency Core Cooling Systems were operable. Failure of this inverter only pre-cludes proper operation in the automatic flow control mode. The rest of the RCIC system remains fully operational and functional under a low level start signal. The RCIC remains fully operable in the manual con-trol mode . The time from the initial tripping until a replacement de-vice was installed and checked was less than I hour. Therefore, the safety implications are minimal for this occurrence.

Corrective Action:

It was determined that the failure was within the RCIC in-verter itself by isolating it from its load and observing that it would only stay on for a few seconds. The inverter was immediately replaced with an identical good spare and returned to service. Recalibration of the automatic resec circuit has corrected the malfunction.

Failure Data; Six other trippings of RCIC inverters have been reported as Abnormal Occurrence Report Numbers 50-277-74-14, 50-277-74-20, 50-277-74-37, 50-277-74-39, 50-277-74-40 and 50-278-74-5.' '

Very truly yours,'

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'i M. J. Cooney Ass 't Gen' t Superintendent Generation Division cc: Mr. J. P. O'Reilly Director, Region i United States Atomic Energy Conaission 631 Park Avenue King of Prussia, PA 19406 t

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