ML20086J227

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

ML20086J227
Person / Time
Site:	Peach Bottom
Issue date:	11/19/1974
From:	Ullrich W PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20086J225	List: ML20086J223 ML20086J227
References
AO-74-24, NUDOCS 8401230336
Download: ML20086J227 (1)

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PHILADELPHIA ELECTRIC COMPANY Peach Botton Atonic Power Station Delta, Pennsylvania 17314 Irovcabar 19, 1974 Hr. Janes P. O'Reilly, Director United S:ates Atonic Energy Consission Dirsctorate of Regulatory Operations 631 Park Avenus Kin 8 of Prunnia, Pennsylvania 19406 Subj ect_: Abnormal Occurrence 24-Rour liotification ,

Confirmina R. S. Pleiocleann's conversation with Mr, Walt Baunack, A.E.C. Region 1 Eegulatory Operations Office on Novenber 19, 1974.

Rafcronco: License Number DPR-56 Technien1 Specification Reference Table 3.1.1 P.: port I:o. : 50-278-74-24 Raport Date: Ibvenbar 19, 1974 Occurrence Date: Novenber 18, 1974 Freility:

Peach Botton Atosic Power Station R.D. 1. Delta Pennsylvania 17314 Id:stification of Occurrence:

Satpoint ch1f t on M-3-5-11D, low condenser vacuum RPS trip.

Conditions Prior to Occurrenco:

Unit 3 operating at greator than 90%.

Description of Occurrence:

Durins 22.7 inchesroutino Ug. instrucent surveillance testing PS-3-5-11B was found to trip at 23 inches U . The Technical Specification limit is greatur than or equal to De01: nation of apparent Cause of Occurrence:

Setpoint chift.

Analysis of Occurrence: '

Ths contacts of this device are arranged in e one-out-of-tte twice trip loaie. The cetpoint of this devico, not the trip function, was unsatisfactory. All other devicet cperationalthe nonitoring parancter and correctlyofcalibrated.

condenser vacuun vero inmediately tested and found to be has ninimi safety 1.plications.

- Becauce of the above reanons 3:his occurrence Cortcetivo Action:

Tha cut-of-toleranco pressure switch was irnedfately recalibrated to within the cllowabic limits of the per tha applicable Technicaltest.

curveillance Specifications and checked for proper calibration The other three devices conitoring the sane variable vare tested and found to be natisfactory in both function and netpoint.

Failure Data:

Sotpoint cs shifta on this type devico in this service have been reported previously A0-50-277-74-1 AO-50-277-74-19, A0-50-277-74-35, asut A0-50-277-74-43.

Vcry truly yours.

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