ML19207B858

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Forwards LER 79-024/01T-0
ML19207B858
Person / Time
Site: Peach Bottom Constellation icon.png
Issue date: 08/29/1979
From: Cooney M
PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To: Grier B
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19207B859 List:
References
NUDOCS 7909050436
Download: ML19207B858 (2)


Text

' ' . %1. 5 PHILADELPHIA ELECTRIC COMPANY 2301 M ARKET STREET PHILADELPHI A. PA.19101 (215)841-4000 August 29, 1979 Mr. Boyce H. Grier, Director Office of Inspection and Enforcement Region I United States Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406

Dear Mr. Grier:

SUBJECT:

Licensee Event Report Narrative Description The following occurrence was rep or ted to Mr. Greenman, Region I, Office of Inspection and Enforcement on August 16, 1979.

Reference:

Docket Number 50-278 Report No: LER 3-79-24/1T Report Date: August 29, 1979 Occurrence Date: August 15, 1979 Facility: Peach Bottom Atomic Power Station R.D. 1 Delta, PA 17314 Technical Specification

Reference:

Technical Specification 6.9.a(9) requires reporting

" performance of structures, systems, or components that require remedial action or corrective measures to prevent operation in a manner less conservative than assumed in the accident analysis in the safety analysis report..."

Description of the Event:

The continuing seismic anchor inspection program being performed in response to IE Bulletin 79-02 identified three shell type anchor bolts on a f our anchor bolt support which failed to torque properly. This anchor plate, 3 - 1011 B - 51 1, supports a vertical leg of the 3D Residual Heat Removal (RHR) pump suction piping downstream of valve MO-15. e f

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Mr. Boyce H. Grier Page 2 August 29, 1979 LER 3-79-24/1T Consequences of Event:

Failure of the anchor support and piping during a seismic event could lead to flooding of one of four RHR rooms. Because the redundant RHR pumps and the back-up Core Spray System are available, the safety significance is considered minimal.

C'ause of Event:

Investigation indicates the most probable cause of failure for these anchor bolts was improper installation.

Corrective Action:

Following the notification of the test failed anchor bolts, the RHR piping section involved was valved out of service.

Redundant ECCS equipment was tested to prove operability. The three test failed anchor bolts were replaced with wedge type bolts and repairs were completed within 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />. The 3D RHR pump was returned to service and proven operable by surveillance testing. Corrective action has been completed.

The anchor inspection program as required by IE Bulletin 79-02 is continuing and will serve to ensure that all seismic anchors are satisfactorily installed.

Previous Similar Occurrences:

3-79-23/1T, 3-79-19/1T, 2-79-32/1T, 2-79-35/1T, 2-79-33/1T.

Yours truly, W- W',

'N M . 'J . Cooney Superintendent Attachment Generation Division-Nuclear cci Director, NRC - Office of Inspection and Enforcement Mr. Norman M. Haller, NRC - Office of Management &

Program Analysis 31d Ed