ML20086K606

AO 74-50:on 741107,standby Gas Treatment Sys Fan B Failed to auto-start on Simulated Failure of Fan A.Caused by Two Contacts of Control Relay Failing to Complete Control Circuit to Start Fan.Relay Contacts Cleaned

ML20086K606
Person / Time
Site:	Peach Bottom
Issue date:	11/17/1974
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
References
AO-74-50, NUDOCS 8401270351
Download: ML20086K606 (2)

Text

O O 4 PHILADELPHIA ELECTRIC COMPANY N

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PHILADELPHIA. PA.19101 '..- Nd." ~4D ,

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' ' e '. . .{.M-November 17, 1974 Co-271 Mr. A. Giambusso Deputy Director of Reactor Projects United States Atomic Energy Commission Directorate of Licensing Washington, D.C. 20545

Subject:

Abnormal Occurrence The folic, wing occurrence was reported to Mr. Don Caphton, A.E.C. Region 1 Regulatory Operations Office on November 8,1974.

Written notification was made to Mr. James P. O'Reilly, Region 1 Regulatory Operations Office on November 8,1974. In accordance wi th Section 6.7.2.A of the Technical Speci fications, Appendix A of DPR-44 for Uni t 2 Peach Bottom Atomic Power Station, the following report is being submi tted to the Directorate of Licensing as en Abnromal Occurrence:

Reference:

License Number DPR-44, Amendment Number 1 Technical Specification Tabic 3 7.B Report No.: 50-277-74-50 Report Date: November 17, 1974 Occurrence Date: November 7, 1974

, Facility: Peach Bottom Atomic Power Station R.D. 1, Delta, Pennsylvania 17314 Identification of Occurrence:

"B" Standby Gas Treatment System Fan failed to auto-start on a simulated failure of the 'A8 fan.

Conditions Prior to Occurrence:

Reactor shutdown. Coolant temperature approximately 1200 F.

i Oboooh7 1107b PDR /

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[ COM SENT REGION ' s

7.

Mr. Giambusso November 1 197 Pags 2

', Description of Occurrence:

During rountine surveillance testing of the Unit 2 PCIS Logic System Functional, a Group II and Group III isolation was ini tiated.

The 'A' SSGTS fan auto started and was then manually tripped to allow the 'B' SBGTS fan to auto-start. At this point in the test, the 'B'

- fan did not auto-start.

Designation of Apparent Cause of Occurrence:

An investigation of tbc logic circuit which starts the 'B' SBGTS fan showed that two contacts of a control relay failed to complete the control ci rcui t to start the fan. The relay did energize and all other contacts on the relay performed their design function.

Analysis of Occurrence:

After the PCIS Logic was reset, the 'B' and 'C' Standby Gas Treatment Fans were run to prove their operability. Both fans ran satisfactorily. Because all three fans and both filter trains of the Standby Gas System were proven to be operabic, there were no adverse safety implications due to this failure.

Corrective Action:

The relay contacts were cicaned by relay technicians and the control circuit was then proven to operate properly through the contacts that were c1 car

d. The surveillance test was rerun sati sfactori ty.

Failurc Data:

I .Nonc previous.

Very truly yours,

/ 'n ' , u . _

. M. /J. 'Cooney f Ass' t Gen'1 Superintendent

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Generation Division cc: Mr. J. P. O'Reilly i Director, Region i United States Atomic Energy Commission 631. Park Avenue i

King of Prussia, FA 19406 l

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