ML20086K896

AO 74-31:on 740601,HPCI Pump Discharge Valve MO-23-20 Failed.Cause Unknown.New Valve Stem Installed & Valve Operability Verified

ML20086K896
Person / Time
Site:	Peach Bottom
Issue date:	06/11/1974
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
References
AO-74-31, NUDOCS 8402070061
Download: ML20086K896 (2)

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PHILADELPHIA ELECTRIC COMPANY vi,7 D'V 2301 MARKET STREET '

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PHILADELPHIA. PA.19101 ,

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'QY Mr. A. Giambusso Deputy Director of Reactor Projects United States Atomic Energy Ccmmission 50-277 Directorate of Licensing - "

Washington, DC 20545

Subject:

Abnormal Occurrence The following occurrence was reported to Mr. Phil Stohr, AEC Region 1 Regulatory Operations Office on June 2, 1974. Written notifi-cation was made to Mr. James P. O'Reilly, Region 1 Regulatory Operations Office on June 3, 1974. In accordance with Section 6.7 2.A of the Technical Specifications. A n,ne ntt i v A nt npD l.6!.6 ene 4.t., i t ? Danch sa nt + nm Atomic Power Station, the following report is being . submitted to the Directorate of Licensing as an Abnormal Occurrence.

Reference:

License Number DPR-44, Amendment Number 1 -

Technical Specification 3 5.C.1 and Table 3 7 4 Report No.: 50-277-74-31 Report Date: June 11, 1974 Occurrence Date: June 1, 1974 Facility: Peach Bottom Atomic Power Station R. D. 1, Delta, Pennsylvania 17314 Identification of Occurrence:

Failure of HPCI pump discharge valve (M0-23-20) .

Conditions Prior to Occurrence:

Reactor shutdown with primary coolant temperatures less than 212 F and the reactor pressure vessel vented.

Description of Occurrence:

During a routine test of components fed from a motor control center which had been returned to service following the installation of J.

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seismic lateral restraints, ,tFm HPCI pump discharge valve motor was observed to operate without moving the shaft of the valve in or out.

The valve stem wa,s rotating freely.

Designation of Apparent Cause of Occurrence:

Investigation and dismantling of the valve indicated that the valve stem had sheared just above the point at which it connects to the vlave disc. The investigation into the cause of the shaft failure is still in progress at this time. A detailed review of the work performed on tnis particular valve is being made in order to determine the exact mechanism for failure. At the present time it appears a possible reversal of the polarity to the limitorque motor during the performance of the work assochated with the electrical seismic restraints may be the cause. A complete report will be available

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on site af ter the investigation is canpleted.

Analysis of Occurrence:

The inner HPCI pump discharge valve is normally in the open position when the HPCI is in standby ready for automatic initiation.

The failure of this valve therefore does not affect the operability of the HPCI system and therefore has minimal safety significance.

Corrective Action:

, Following investigation, 2 new valve stem was installed and valve operabil.ity verified.

Failure Data:

No previous failures of this valve have Ecen reported.

Very truly yours, l

f--hC%f M. J. Cooney [

A 't Gen' t Superintendent s

Generation Division cc: Mr. J. P. O'Reilly Director, Region 1 United States Atomic Energy Commission l

631 Park Avenue

! King of Prussia, PA .19406 l

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