ML20084U853

Interim Deficiency Rept Re Coupling & Gasket Failures in RHR & EECW Sys.Initially Reported on 730507.Preliminary Investigation Indicates Cause Is Water Hammer.Investigation Continues.Final Rept to Be Provided by 730710

ML20084U853
Person / Time
Site:	Browns Ferry
Issue date:	06/06/1973
From:	Gilleland J TENNESSEE VALLEY AUTHORITY
To:	Kruesi F US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20084U431	List: ML20084U446 ML20084U462 ML20084U499 ML20084U519 ML20084U551 ML20084U609 ML20084U662 ML20084U689 ML20084U853 ML20084U869
References
10CFR-050.55E, 10CFR-50.55E, NUDOCS 8306290322
Download: ML20084U853 (2)

Text

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~. TENNESSEE CHATTANDOG VALLEYTENNESSEE AUTHOAITY OTT q< ']

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' Lri 1 L j ANN'thEMGNUY OS[rONEs$

Jane 6, 1973 {

4%VCt Mr. F. E. Kruesi, Director NfeY Directorate of Regulatory Operations U.S. Atomic Energy Co= mission Washington, D.C. 20545

Dear Mr. Kruesi:

On May 7, 1973, TVA cade initial telephone report to AEC-DRO Inspector W. S. Little of some coupling and gpket failures in Browns Ferry RHR and EECW syatems.

Enclosed is an interim report on these failures; investigation into their causes is continuing,and we expect to submit a final report by July 10, 1973.

Very truly yours, J. E. Gilleland Assistant to the Manager of Power Enclosure CC (Enclosure):

Mr. Norman C. Moseley, Director Directorate of Regulatory Operations U.S. Atomic Energy Cocmission Region II - Suite 818 230 Peachtree Street, NW.

Atlanta, Georgia 30303 8306290322 740617 PDR ADOCK 05000259 S PDR

1 l

• 1 . -

o ENCLOSURE 0 -

j,;. - ~

Failure of RER Service Water System Dresser Coupling g j, - ,

and Emergency Equipment Cooling Water Systems Gasket '

.x Sequence of Events: ,

I I May 3, 1973, 10 a.m. - RHR service water header lA Dresser Coupling ruptured in the unit 1 pipe tunnel outside the reactor building.

This occurred immediately after starting the A-2 RER service water pump at the intake building. All RER unit 1 heat exchanger valves were in the closed position. Persons working in the vicinity of the rupture reported considerable vibration and movement of the header just before rupture.

II May 6, 1973, 6:10 a.m. - An orifice flange gasket in the diesel generator building supplying emergency equipment cooling water from the EECW system blev out. This occurred immediately after starting an RHR service water pump at the intake building which furnishes water to this system. Considerable pipe vibration was observed by persons in the vicinity just before the gasket failure.

III May 10,1973,10 a.m. - RHR service water header 3C Dresser Coupling ruptured in the unit 3 pipe tunnel outside the reactor building. This occurred immediately after starting RER service water pump Al at the intake building. The "C" header was valved closed at unit 1-C, 2-C, and 3-C heat exchangers. Pump Cl was operating and the crosstie from pump Cl to*C header was open and delivering approximately 2000 gpm to that line. No observation was made of vibration or movement of the piping at the time of rupture nor was the A-1 pump valved to the "C" header. Examination of the ruptured coupling indicates it may have been faulty.

IV May 23, 1973 - RHR service water header lA Dresser Coupling ruptured in the unit 1 pipe tunnel outside the reactor building. The same conditions existed as above (May 3, 1973).

The preliminary investigation indicates water hammer as the cause of failure; however, the investigation and the determination of the corrective action to be

, taken is continuing. We expect to provide a final report of the failure by l July 10, 1973.

.