ML20127G549
| ML20127G549 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 01/23/1973 |
| From: | Mayer L NORTHERN STATES POWER CO. |
| To: | Anthony Giambusso US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 9211170372 | |
| Download: ML20127G549 (1) | |
Text
Eulatofy F11e T E
NSF NORTNERN 8TATK5 POWER COMPANY Minneapolis, Minnesota 55401
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4 January 23, 1973
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Mr. A. Giambusso 3
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- s Deputy Director for Reactor Projects A
Directorate of Licensing b
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thited States Atomic Energy Occmission S
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i Dear Mr. Gianbusso.
,p MMICEllD NUCIEAR GE2ERATING PIANT j.,
Docket No. 50-263 License No. DPR-22 g
g' Im Condenser Vacutun Scram Switch Diaphragm leak A condition occurred at the Monticello Nuclear Generating Plant recently which we are reporting to your office in accordance with Section 6.6.C.1 of Appendix A, Technical Speci.fications, of Provisional Operating License DPR-22.
i On Friday, January 12, 1973, while performing a routine surveillance test, one "Im Condenser Vacuun Scraaf' switch was found to have a small leak in the netal diaphragm capsule. 'Ibe instrument was innediately replaced with a spare. h ranaining three instrunents and the spare installed wre tested for leakage and wre found acceptable.
h leak discovered did not change the instrument setpoint or cause the instrument to be inoperable. A large leak in this diaphragm would cause the instrunent to trip and is therefore a safe failure".
h cause of the leak has not been identified; however, the leaking diaphragn capsule has been returned to the manufacturer for further analysis. All four l
of the condenser low vacuan scram instruments have been placed on an accelerated eight week surveillance test schedule.
Yours very truly,
>:'O.2 L. O. Mayer,7P..
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Director of Nuclear Support Services IIWuna l-cc: B H Grier l
G Charnoff l
Minnesota Pollution Control Agency, Attn:
K. Dzugan 9211170372 730123 l
PDR ADOCK 05000263 657 /h S
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