ML20086J435

AO 74-9:on 740918,defective HPCI Turbine Bearing Found. Caused by Insufficient Oil Supply to Bearing.Turbine Rotor Shaft & Both Bearings Replaced

ML20086J435
Person / Time
Site:	Peach Bottom
Issue date:	09/28/1974
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
References
AO-74-9, NUDOCS 8401230676
Download: ML20086J435 (2)

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PHILADELPHI A. PA.19101 {' Ad saisi 841-4ooo 44, m mk September 28, 1974 Docket No. 50-278 Mr. A. Giambusso "

Deputy Director of Reactor Projects United States Atomic Energy Commission i Directorate of Licensing

Dear Mr. Giambusso:

Subiect: Abnormal Occurrence j The following occurrence was reported to Mr. Walt Baunack, A.E.C.

Region 1 Regulatory Operations Office on September 19, 1974. Wri tten notification was made to Mr. James P. O'Reilly, Region i Regulatory Operations Of fice on September 19, 1974. In accordance wi th Section 4.7.2.A of the Technical Specifications, Appendix A of DPR-56 for Unit 3 Peach Bottom Atomic Power Station, the following report is being submitted to the Directorate of Licensing as an Abnormal Occurrence:

Reference:

License Number DPR-56 Technical Specification Reference 3.5.C Report No.: 50-278-74-9 Report Date: September 28, 1974 Occurrence Date: September 18, 1974 Faci li ty: Peach Bottom Atomic Power Station R.D.1, Del ta, Pennsylvania 17314 Identification of Occurrence:

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Defective HPCI turbine bearing.

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Conditions Prior to Occurrence: .

r ,o Maintenance outage in progress. Reactor shutdown.

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$cg. Description of Occurrence: gfac_/

e ca f During HPCI turbine test operation, a small steam leak was

! noted at the pump und turbine shaf t packing. No other HPCI turbine or system 3bnormali ty. could be detected during operation. Following I

COPY SENT REGION ,/m /

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. Mr. A. Giambuss]6 September 28,1 P:ga 2 a scheduled plant shutdown, examination of the turbine indicated that the pump end turbine bearing had wiped resulting in a downward dis-placement of the turbine shaf t. This shaf t displacement resulted in damage to the carbon ring steam packing.

Designation of Apparent Cause of Occurrence:

Inspection of the failed bearing by personnel from Philadelphia Electric Company, General Electric Company, and the Terry Turbine Company, indicated that the failure was probably due to insufficient oil supply to the bearing. Inspection of tne oil supply piping and valves to this bearing revealed no blockage to oil flow. The conclusion was that the blockage was temporary in nature, and had been corrected prior to dis-covery of the problem. .

Analysis of Occurrence:

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The HPCI system was successfully operated for a five hour period following the loss of power testing on September 17, 1974. It was during a minor maintenance inspection of a shaft seal that the damaged bearing was uncovered. It is concluded that either the damage to the bearing occurred during the system shutdown or was insufficient to seriously affect system performance. The HPCI system, therefore, was available during power operation, and for a period after shutdown I

sufficiently long such that the bearing damage had a minimal effect on safety.

Corrective Ac' tion

• The turbine rotor shaf t and both bearings are being entirely replaced. The oil system has been mechanically cicaned and flushed.

All instrument and control devices will be calibrated or functionally tested.* Prior to plant start-up, the turbine will be run on auxiliary steam both uncoupled and coupled to the HPCI pumps. During these runs, turbine bearing lubrication will be closely monitored, and selected portions of the pre-operation test will be repeated to prove the opera-bility of the system. It is estimated that all work will be complete on9/30/74

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Failure Data:

None.

Very truly yours,

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4 dJ.Cooney-Ass' t . Gen'1 Superintendent cc: Mr. J. P. O' Rei lly Generation Division Di rector, Regic.1 1 United States Atomic Energy Commission

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