ML20084S977
| 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 h
Monticello, Minnesota 55362 il March 25, 1974' ij Hp N
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 hc
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:
[v 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 j.
a total Icakage rate of only 4.6 SCFH ficm the three valves. The voltne was 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.
s3o6200349 740325 l
PDR ADDCK 05000263
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PDR 43 W
Yours very truly, s
C.
fE E
Plant Manager
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tu.M cc: J F O' Leary, Directorate of Licensing G3 7/
00
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G Charnoff
' Minnesota Pollution Control Agency, Attn: E A Pry ina-Copie. nt by telecopier to Kenpler and O'Learv b
COPY SENT REGION
.