ML20086J223

AO 74-24:on 741118,low Condenser Vacuum RPS Trip PS-3-5-11B Trapped at 22.7 Inches.Caused by Setpoint Shift.Out of Tolerance Pressure Switch Recalibr

ML20086J223
Person / Time
Site:	Peach Bottom
Issue date:	11/28/1974
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20086J225	List: ML20086J223 ML20086J227
References
AO-74-24, NUDOCS 8401230333
Download: ML20086J223 (2)

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s PHILADELPHI A ELECTRIC COM PANY 2301 M A R K ET STR EET PHILADELPHI A. PA.19101 .

N (215)841-4000 Novcmber 28, 1974 Mr. A. Giambusso Deputy Director of Reactor Project s Uni ted States Atomic Ener gy Ccemi ssion Directorate of Licensing Wa shi n g ton , D. C. 20545

Subject:

Abnorna1 Occurrence The folicwing occurrence was reported to Mr. Walt Baunack, A.E.C. Region 1 Reculatory Operations Of fice on November 19, 1974.

Written notification was made to Mr . Jemen P. O ' Rei l ly, Region 1 Renulatory Operations Of fice on November 19, 1974 In accordcnce with Section 6.7 2.A of the Technical Specifications, Appendix A of DPR-56 for uni t '2 Peach Bot tom Atenic Power Station, the following report i s beinc submit ted to the Directorate of Licensing as an Abnormal Occurrence.

Refercnce: License Number DPR-56 Technical Specification Reference Tabic 31.1 Report No.: 50-278-74-24 Report Date: Novcmber 23, 1974 Occurrence Date: Nover.ber 13, 1974 Facili ty : Peach Bottem Atomic Power Station R .D . 1, Delta, Pennsylvania 17314 Identifica tion of Occurrcnce:

Se t poi nt shi f t on PS-3-5-llB, low condenser vacuum RPS trip.

Conditions Pricr to Occurrence:

Uni t 3 opera ti r,g a+ grcater than 90%.

Description of occu r rence:

During routine instrtracnt surveillance testing, PS-3-5-llB was found to trip at 22 7 inc.hes Pc. The Technical Speci fica tion limit is greater than or x;ual to 23 inches Hg.

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r13 \s Mr. A. Giambusso November 28, 1974 Page 2 Desi cnation of Apparent Cause of Occurrence:

A Se t poi n t shi f t.

Analysi s of Occurrence:

The contacts of thi s device are arranged in a one-out-of-two twice trip logic. The setpoint of thi s device, not the trip f unction, was unsati sfac tory. All other devices moni toring the parameter of condenser vacuum were immediately tested and found to be operational and correctly calibrated. Because of the above reasons thi s occurrence has minimal saf ety imolicctions.

Corr ec ti ve Action:

l The out-of-tolerance pressure swi tch was immediately j recalibratcd to wi thin the allowable limi t s of the Technical Specifications

! and checked for proper calibration per the applicabic surveillance test.

i The other three devices moni tering the same variable were tested and found to be sa ti sf actory in both f unction and setpoint.

Fai lure Da ta: f Setpoint shif ts on this type device in thi s service have been repor ted previously as A0-50-277-74-1, A0-50-277-74-19, A0-50-277 35, I

and AC-50-277-74-43 l

'fery truly your s ,

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/M.//J. "Cooney fy n A' !

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A s s ', t . General Superintendent Generation Divi sion cc: tir . J . P. O ' Rei l l y Director, Regien i Uni ted States Atomic Energy Commi ssion 631 Park Avenue King of Prussia, Pe nn sy l varei a 19406 i

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