ML20086K934

AO 74-27:on 740520,core Spray Inboard Injection Valve MO-12B Failed to Open During Testing.Caused by Burned Out Motor.Motor Replaced & Applicable Testing Procedures Being Rewritten

ML20086K934
Person / Time
Site:	Peach Bottom
Issue date:	05/30/1974
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
References
AO-74-27, NUDOCS 8402070081
Download: ML20086K934 (3)

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May 30, 1974 .yJJL'49 :)~

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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. R. A. Feil. A.E.C. Region i itegulatory operaticns Ortice on May 21, 1974. Written notifi-cation was made to Mr. James P. O'Reilly, Region 1 Regulatory Operations Office on May 21, 1974. In accordance with Section 6 7.2.A of the Tech-nical Specifications, Appendix A of DPR-44 for Unit 2 Peach Bottom Atomic Power Station, the f ollowing report is being submitted to the Directorate of Licensing as an Abnormal Occurrence.

Reference:

License Number DPR-44, Amendment Number 1 Te'chnical Specification Reference 4 5.A.1 Report No.: 50-277-74-27 Report Date: May 30, 1974 Occurrence Date: May 20, 1974 Facility: Peach Bottom Atomic Power Station R. D. 1, Delta, Pennsylvania 17314 Identification of Occurrence: Failure of MO-128 core spray inboard injection valve to open during testing.

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8402070081 740530 gV , PDRADOCK05000g77 DR i S b 4972 COPY SENT REGION /

r-O Mr.A.Giambussob j Mayj 30, 1974 Page 2  ; t Conditions Prior to Occurrence: Plant operating at about 70% power. Description of Occurrence: During surveillance testing, the "B" loop core spray injection valve M0-128 failed to open when requested. Designation of Apparent Cause of Occurrence: Burned-out motor. Analysis of Occurrence: The motor operater on this valve is rated to open the valve with a 400 psi differential pressure across the valve gate. Previous experience had indicated that the operator was capable of opening the valve at approximately 900 psi differential. Because of this previous experience, a planned method of equalizing pressure across the valve, during periods of testing, was not used and had not been included in the testing procedures. When the valve operator was energized it

ppercr.t l y cvvid noi vpen die valve with approximately 1,uuu psi ditter-ential across it, and as a result, the motor failed. Manual operation of the valve indicated the extreme difficulty of stroking it until the pressure had been equalized across the gate, af ter which the valve operated easily.

At the time of the occurrence all other low pressure core cooling systems were operable and all diesel generators were operable. The loss of one core spray system for the short period of time re-quired to replace the valve motor has minor safety significance since sufficient low pressure core cooling systems were availabic to respond in any accident situation. Corrective Action: The burned-out motor was replaced. The applicable testing procedures are being rewritten to require pressure equalization across the valves prior to test opening. These revisions will be completed before the next surveillance test on these valves is performed. During the investigation and motor replacement, testing was begun on the diesci generators and the remaining low pressure ECCS systems as required by Technical Specifications. Repair _and testing of the valve was completed prior to completion of all the aforegoing required surveillance testing, and the "B" c. ore spray system was de-clared operable.

        ,Mr. A. Giambusso                                                                    F May 30, 1974                                                       Paga 3         L
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a i-: : None Previous. q < 7 l r Very truly yours, ir

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M./il. Cooney ..) h As',s't Gen'1 Superintendent Generation Division t. cc: Mr. J. P. O'Reilly Director, Region i United States Atomic Energy Commission 631 Park Avenue King of Prussia, PA 19406

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