ML20058K554
| ML20058K554 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 08/04/1972 |
| From: | Mayer L NORTHERN STATES POWER CO. |
| To: | Anthony Giambusso US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 9102120479 | |
| Download: ML20058K554 (1) | |
Text
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NORTHERN STATES POWER COMPANY MIN N E A Pobl S. M S N N E S OTA 55401
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August 4,1972
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Q' Mr. A Giambusso O
7 Deputy Director for Reactor Projects
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Directorate of Licensing 9
A 3 United States Atomic Energy Commission Washington, D.C.
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Dear Mr. Giambusso:
MONTICELLO NUCLEAR GENERATING PLtdT Docket No. 50-263 License No. DPR-22 Reporting of HPCI Turbine Exhaust Check Valve Leakage A condition occurred at the Manticello Naclear Generating Plant recently which we are reporting to your office in accordance with provisions of Section 6.6.B.3 of Appendix A, Technical Specifications, of the Provisional Operating License DPR-22.
Region III of the Directorate of Regulatory Operations has been notified of this occurrence.
On July 27, 1972 Northern States Power Co=pany reported to the Directorate of Licensing a failure of the HPCI turbine exhaust line stop check valve HPCI-10 (ie: failure of the disc pin and repair modification).
Following repairs to
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valve HPCI-10,, a leak test was performed by air pressurization of the zone i
between HPCI-10 and HPCI-9; the latter is the swing check valve imediately upstream of HPCI-10.
This test indicated about 400 sefh total air leakage from the pressurized zone and that a significant portion of this total was attributable to HPCI-9 Probable concurrent conditions of the HPCI-10 failure and this leakage of HPCI-9 constitute an Abnormal Occurrence as defined under Section 1.A.5 of the Technical Specifications.
Both valves were disassembled and repairs were performed in accordance with
=anufacturer's recomendations. Subsequent to this work the leak test was repeated and results indicated a total leakage of less than two sefh.
Details of this occurrence vill be included in the Abnomal Occurrence Report on the HPCI-10 valve and vill be available at the site for the Regulatory Operations inspector.
N Yours very truly,
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L.O. Mayer, P.E.
.Y Director of Naclear Support Services 4(Jg /Sg
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