ML20084R999

AO 50-249/74-27:on 740928,following Surveillance of Core Spray Sys,Core Spray 3A Discharge Header Pressure Was Lost. Caused by Discharge Stop Check Valve 3-1402-8A Failure to Seat Properly.Valve Manually Cycled

ML20084R999
Person / Time
Site:	Dresden
Issue date:	09/03/1974
From:	Stephenson B COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20084S002	List: ML20084R999 ML20084S018
References
628-74, AO-50-249-74-27, NUDOCS 8306160102
Download: ML20084R999 (2)

Text

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's*Q : MC'ess %%y to: Post 01: ce Bsi7G7 V Chicago, Ilknois 60690 BBS Ltr.*628-74 Dresden Nuclear Power Station R. R. #1 -

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q.1-Mr. Ja=es G. Keppler, Regional Director C

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Directorate of Regulatory Operations-Region III U. S. Atomic Energy Co= mission gk ' , , ~

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Glen Ellyn, Illinois 60137 \:i. ,

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SUBJECT:

REFCRT CF AE::0F;:AL CCCt.'RREN*0E PER SECTION 6.6.B 0F THE TECHNICAi, SFECIFLJATIC::5.

C;IT- 3 "A" CCd5 SFRAY FEADER

References:

1) Regulatory Guide 1.16 Rev.1 Appendix A

2) Notification of Region III of AEC Regulatory Operations Telephone: Pr. F. Maura, 1420 hours0.0164 days <br />0.394 hours <br />0.00235 weeks <br />5.4031e-4 months <br /> en August 26, 1974 Telegram: Fr. J. Keppler, 1k20 hours on August 25, 1974

3) Drawing N='cer: M-358 Report N=ter: 5;-249/197t-27 Report Date: Septer!cer 3, 1974 Occurrence Date: August 28, 1974 Facility: Dresden Nuclear Fewer Statien, Merris, Illinois IDE'~r:FICAT~CN CF CCCGRZ::E Cn Aurast 23, 197h at atent 0500 hcurs, 3 "A" cerc sprcy header pressure was lesc.

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Prior to the loss of core spray header pressure, the 3A core spray pu=p was cperated to perfcrm surveillance prior to taking the 2/3 diescl generator cut of service.

DESCRIP*!C:' CF CCC3RE::E l At atcut 0500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br /> on August 29, 1974 following surveillance of the core spray system, core spray 3A discharge header pressure was lost. The irs::ediate ccticn taken was to check the 3A core spray syste= valve line up.

It was found curing the valve line up check that the 3A core spray pump discharge stop-check valve (3-1402-SA) dia not ceat following surveillance. ,y 8306160102 740903 5 } pr Y / .sfpW,' ic ,

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-V Mr. James G. Kepp S3ptember 3, 1974 r

DESIGNATION OF APPARE.T CAUSE (Valves)

The apparent cause of the loss of 3A core spray header pressure at the time of the occurrence was due to the dischuge stop-check valve (3-1402-8A) failing to seat properly.

ANALYSIS OF OCCURRE!CE During the loss of the 3A core spray pump discharge header pressure the safoty of the plant and public was not in jeopardy. The 3B core spray system and all other emergency core cooling systems were operable at the time of the occurrence.

CORRECTI'.~i, ACTICM l

The icrediate corrective actiens taken following the discovery was to canually cycle valve 3-1402-8A which seated the s cp-check valve allowing '

discharge header pressure to return to nor=al. Following the return of normal header pressure, the line was vented.

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. . In order to recove the 2/3 emergency diesel generater frc= service, the core spray system surveillance was perferred again. During this surveil-  ;

lance, the problem did not reappear. Bewever, the s:cp-creek valve will be inspected during the next four day cutage.

FAI'.UR DATA In review of past data, no previcus failures of this type were found. In view cf the prcbler and no previcus failures, the corrective acticn taken at this time is considerad satisfactory.

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B. B. Stephenson l Superintenden BBS:do l

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