ML20084S977

Ro:On 740322,during Primary Containment Isolation Valve Local Leak Rate Testing,Core Spray Valve a Check Valve AO 14-13A Found Leaking in Excess of Tech Spec Limits & Excessive Amount of Time Needed to Pressurize Valve Areas

ML20084S977
Person / Time
Site:	Monticello
Issue date:	03/25/1974
From:	Larson C NORTHERN STATES POWER CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
NUDOCS 8306200349
Download: ML20084S977 (1)

Text

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. mp st co auf N O R T H E: RN SvATES POWER COMPANY Monticello, Minnesota 55362 h

il March 25, 1974' ij H

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Mr. J. G. Keppler, Regional Director M Directorate of Regulatory Operations i{

Region III h United States Atcaic Energy Coamission ji 799 Roosevelt Pcad P Glen Ellyn, Illinois 61073 h

c

Dear Mr. Xeppler:

U li IOhTICEL10 NJC114R GENSPJJIhU PLAhT 4 Docket No. 50-263 License No. DPR-22 $

j As a result of' primary containment isolation valve local leak rate testing perforced q on M1rch 22, 1974, the following occurrences are hereby reported

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1. The "A" Core Spray System testable check valve, AD 14-13A, was found to be (

icaking 290 SCOf. Tnis is in excess of the acceptance criteria for local i icak rate tests specified in section 4.7.A.2.f. of the TeCmical Specificatiens, j The redundant isolation valve in this line, 10 1753, was found to have zero d Icakage. An investigation into the cause of the leakage past AD 14-11; will h be conducted prior to retuming to pcuer operatien. i 1

2. It took an excessive arctmt of tice to pressurize the area between Printry '

Centairacnt Atrospheric Control Systcn isolatica valves, A0 2377, A0 2373 and j AD 23S1 until a pressure of cpprcxicately 25 psig was obtained. At 25 psig,  !

the Icakage appeared to. stop and the voltme was pressurized to the recuired i 41 psig test pressure in a reasonable tina interyc1 ccasidering the voltre of (

l the area being pressuri:cd. A local leak vate test perforced at 41 psig indicated

j. a total Icakage rate of only 4.6 SCFH ficm the three valves. The voltne was :j j depressurized and tha Icak test was repeated with similar results. The initial j investigaticn of the occurrence revealed that there was significant s:umt of IcaLge past A0 2381 tutil a pressure of approxirately 25 psig was attained, at  ;

. which tim Icakage past the valve appeared to cease. . Corrective actions to be j taken on this valve will be detemined following cc::pletion of the occurrence investigation.

l s3o6200349 740325 PDR ADDCK 05000263 ,11 / go.

Yours very truly, s PDR 43 W C. fE E Plant Manager CEL/ncra

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iAP u.tuf @9 h, 4 i'

b ':) .M cc: J F O' Leary, Directorate of Licensing G3 7/

G Charnoff .

' Minnesota Pollution Control Agency, Attn: E A Pry ina-00 . g:$ -

- Copie . nt by telecopier to Kenpler and O'Learv COPY SENT REGION b

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