ML20086J213

AO 74-25:on 741119,torus High Water Level Switch LS-3-23-91A Failed to Operate.Caused by Switch Assembly Flapper Arm Interfering Slightly W/Switch Case.Switch Readjusted

ML20086J213
Person / Time
Site:	Peach Bottom
Issue date:	11/29/1974
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20086J217	List: ML20086J213 ML20086J218
References
AO-74-25, NUDOCS 8401230321
Download: ML20086J213 (2)

Text

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O PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET PHILADELPHIA, PA.19101 ' -' '

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y November 29, 1974 d;=,.

Mr. A. Giambusso Deputy Director of Reactor Projects United States Atomic Energy Commission Directorate of Licensing Washington, DC 20545

Subject:

Abnormal Occurrence The following occurrenca was reported to Mr. Walt Baunack, A.E.C. Region 1 Regulatory Operations Office on November 20, 1974.

Written notification was made to Mr. James P. O'Reilly, Region 1 Regulatory Operations Office on November 20, 1974. In accordance with Section 6.7 2.A of the Technical Specifications, Appendix A of DPR-56 for Unit 3 Peach Bottom Atomic Power Station, the following report is being submitted to the Directorate of Licensing as an Abnormal Occurrence.

Reference:

License Number DPR-56 Technical Specification Reference Table 4.2.B Repor t No.: 50-278-74-25 Report Date: November 29, 1974 Occurrence Date: November 19, 1974 Facility: Peach Bottom Atomic Power Station R.D. 1, Delta, Pennsylvania Identification of Occurrence:

Failure of a torus high water level switch LS-3-23-91A to operate. This switch cperates to transfer the HPCI suction from the condensate storage tank to the suppression pool.

Conditions Prior to Occurrence:

Unit 3 at greater than 90% power.

Description of Occurrence:

During a routine instrument surveillance test, LS 23 - 91 A failed to operate. pl d7 j' e Designation of Apparent Cause of Occurrence:

y d55-The switch assembly flapper arm was found - to interfere slighplyp..

with the switch case. D- ' /V Q 1 $ $ o ! !o1 fo M e COPY SENT REGION M c=

S PDR _ _ _ - - - _ - - _ _ _ _ - _ - - _ _ _ _ _

Mr. A. Giambusso (

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November 29, 1974 Page 2 Analysis of Occurrence:

LS-3-23-31A and LS-3-23-91B operate independently to transfer the HPCI suction from the condensate storage tank to the suppression pool. LS-3-23-918 had just been tested and found to function properly.

Because the f ailure of LS-3-23-91A to operate would not have interfered with the' proper operation of the system, the safety implications are minimal.

Corrective Action:

The switch was reacjusted to allow proper operation of the switch. The switch was cycled a number of times using water to lif t the float to ensure reliable operation. and then rechecked using the appro-priate instrument surveillance test.

Failure Data:

No previous failures on this type of switch.

Very truly yours, I. 1 ,

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MJ .l' iCooneyf

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Ass't Gen'1 Superintendent

' Generation Division cc: Mr. J. P. O'Reilly Director, Region 1 United _ States Atomic Energy Commission 631 Park Avenue King of Prussia, PA 19406 l-I l

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