ML20086J172

AO 74-33:on 741204,main Steam Line High Flow Switch DPIS-3-2-116C Failed to Trip During Surveillance Test.Caused by Slight Mechanical Binding.Face & Scale Removed from Instrument to Observe Linkage During Operation

ML20086J172
Person / Time
Site:	Peach Bottom
Issue date:	12/14/1974
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20086J177	List: ML20086J172
References
AO-74-33, NUDOCS 8401230277
Download: ML20086J172 (2)

Text

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PHILADELPHIA ELECTRIC COMPANY {.. ""'72 S E. , .. .l

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PHILADELPHI A. PA.19101 ~ fg'\

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December 14, 1974 Mr. A. Giambusso Deputy Director of Reactor Projects United States Atomic Energy Commission Directorate of Licensing Washington, DC 20545

Subject:

Abnormal Occurrence The following occurrence was reported to Mr. Wal t Baunack, A.E.C. Region i Regulatory Operations Office on December 5, 1974.

Written notification was made to Mr. James P. O'Reilly, Region 1 -

Regulatory Operations Of fice on December 5,1.974. In accordance with Section 6.7 2.A of the Technical Specifications, Appendix A of DPR-56 for Uni t 3 Pe ac h Bo t t cm A t ccii c P o.ve r S t a t i on , the following report is being submi ttcd to the Directorate of Licensing as an Abnormal Occurrence.

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Reference:

License flumber DPR-56 Technical Specification

Reference:

Table 3 2.A Report i:o.: 50-278-74-33 Report Date: December 14, 1974 Occurrence Date: December 4, 1974 Facility: Peach Bottom Atomic Power Station Unit ti3 R.D. #1, Delta, Pennsylvania 17314 Identification of Occurrence:

Failure of Main Steam Line High Flow Switch dPIS-3-2-116C to trip during a surveillance test.

Conditions Prior to Occurrence:

Unit 3 at approximately 75X power.

Description of Occurrence:

During a routinc' surveillance test, dP IS-3-2-116C f ailed to trip.

8401230277 741214 PDR ADOCK 05000270 #

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7 Mr. h. Giambasso ,

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'D;c{mb:r 14, 1974 o

9 Designation of Apparent Cause of Occurrence: .

Probably a slight mechanical binding. The binding cleared during visual examination of the switch linkage.

Analysis of Occurrence:

There cre no safety implications since its companion switch in e one-of-two logic was operable.

Corrective Action:

Following the f ailure to trip, the fece and scale were removed from the instrument in order to observe the linkage during an operation in order to determine the type of failure. The switch was again tested and this time, and each succeeding time, it worked properly. It was then reassembled, tested and continued to work proper ly. The Switch was again tested two days later and operated p. cperly.

Failure Data:

Previous occurrences on these type switches have been reported as dPIS-2-2-Il9A on 9/6/73 and in Abncrmal Occurrence Reports 50-277 "~~

28, 50-277-74-43, and 50-278-74-20.

Very truly yours, j,1 , 7 l,'J M. . j Cooney

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

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