ML19343B098

AO 50-29/75-4:on 750311,boron Buildup on Elbow Leading to Shutdown Cooling Flow Indicator Was Observed.Caused by Failure of Weld on Sensing Line Elbow.Plant Design Change Initiated

ML19343B098
Person / Time
Site:	Yankee Rowe
Issue date:	03/21/1975
From:	Autio H YANKEE ATOMIC ELECTRIC CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19343B099	List: ML19343B098 ML19343B100
References
AO-50-29-75-4, NUDOCS 8012040261
Download: ML19343B098 (2)

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Mr. J. P. O'Reilly, Director Office of Inspection and Enforcement Region I U.S. fluclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406

Subject:

Abnorr.a1 Occurrence 50-29/75-4 Shutdcan Cooling Flow Indicator Sensing Line Leak

Dear Mr. O'Reilly:

In accordance with Technical Specifica' tion Section E.2.a., the attached report of Abnormal Occurrence 50-29/75-4 is hereby submitted.

l Very truly yours, 4

Herbert A. Autio Plant Superintendent HAA/jb Enclosure cc:

(40) Director of Regulatory Operations i

U.S. iluclear Regulatory Commission b'asnington, D.C. 20545 3117

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ABNORMAL OCCURREf;CE REPORT REPORT' NUMBER:

50-29/75-4 REPORT DATE_:

March 21',1975 0CCURREtiCE DATE:

March 11,1975 FACILITY:

Yankee Atomic Electric Company, Rowe, Massachusetts 01367 l

IDENTIFICATION OF OCCURRENCE: Shutdown Cooling Flow Indicator Sensing Line Leak i

CONDITIONS PRIOR TO OCCURRENCE: Normal steady state power level, gross electrical output at 185 MJe.

DESCRIPTION OF OCCURRENCE On March 11,'1975 at approximately 1145 the supervisor inspecting work in progress in the vicinity of the shutdown cooling flow indicator observed a boron buildup on an elbow leading to the indicator.

Further investi-gation revealed a small leak at the weld. This is a. violation of Technical Specification Section E.4.e.

DESIGNATION OF APPARENT CAUSE OF OCCURRENCE The apparent cause was the failure of the weld on the sensing line elbow.

ANALYSIS OF'0CCURRENCE I

The Shutdown Cooling System is isolated and depressurized during normal-plant operation.

The leakage was so small as to only be indicated by a boron buildup as the escaping liquid slowly evaporated.

Also, since the line was a small instrument tap, if the system was placed -

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in operation it would not have posed any significant hazard.

CORRECTIVE ACTION A Plant Design Change has been initiated to replace the instrument piping and provide a hydrostatic test tap.

FAILURE DATA NA Plant Superintendent il E