ML20086J446

AO 74-7:on 740918,ground Fault Found in RHR Pump Motor 3B. Caused by Insulation Failure.Motor Stator Core Will Be Electrically Tested & Completely Rewound.Repairs Expected to Be Complete by 741009

ML20086J446
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)
Shared Package
ML20086J448	List: ML20086J446 ML20086J451 ML20086J455 ML20086J459
References
AO-74-7, NUDOCS 8401230687
Download: ML20086J446 (2)

Text

~

e -

( . O- O PHILADELPHIA ELECTRIC COMPANY t 2301 M ARKET STREET PHILADELPHI A. PA.19101 (215)8414000 s

i September 28, 1974 Mr. A. Giambusso Deputy Director of Reactor Projects United States Atomic Energy Commission Directorate of Licensing Washington, D. C. 20545

Subject:

Abnormal Occurrence The following occurrence was reported to Mr. Walt Baunack, A.E.C. Region 1 Regulatory Operations Office on September 19, 1974. Written notification was made to Mr. James P. O'Reilly, Region 1 Regulatory Operations Office on September 19, 1974. In accordance with Section 4.7.2.A of the Technical Sp(rifications, 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.A.3 Report No.: 50-278-74-7 Report Date: September 28, 1974 Occurrence Date: September 18, 1974 Facility: Peach Bottom Atomic Power Station R.D.1, Delta, Pennsylvania 17314 Identification of Occurrence:

Ground fault in 3B RHR pump motor.

Conditions Prior to Occurrence:

Maintenance outage in progress. Reactor shutdown.

9 Jh 4J

'p 8401230687 740928

'* ^** '

Eo!

1025 M o m a m u r.mn ' _

~

j.

p Mr. A. Giambusso In') p) s September 28, 1974 k#

,/ Page 2 Description of Occurrence:

The 'B' RHR pump was being started in the shutdown cooling mode.

As the motor was energized, it tripped on instantaneous overcurrent.

Designation of Apparent Cause of Occurrence:

Insulation failure, short to ground.

Analysis of Occurrence:

The motor circuit breaker tripped as soon as the motor was energized.

The punp was to be used in the shutdown cooling mode to cool the reactor to 150 F. Decay heat at this time in core life is small and one of the remaining three RllR pumps was used for this service. There is no safety significa~nce associated with this failure.

Corrective Action:

Prior to the failure, this motor had successfully passed all re-quired electrical and preoperational testing. There is no evidence that the motor experienced anything other than a random insulation failure.

The motor stator core will be electrically tested and then completely rewound. Repairs are expected to be complete by Octcber 9, 1974.

Failure Data:

None.

Very truly yours,

5. J h)

Cooney Ass',1 Gen'l Sup rintendent Generation Divlsion cc: Mr. J. P. O'Reilly Director, Region 1 United States Atomic Energy Commission 631 Park Avenue King of Prussia, PA 19406 t.