ML20086E473
| ML20086E473 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 06/26/1974 |
| From: | Riley B VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML20086E468 | List: |
| References | |
| AO-74-09, AO-74-9, VYV-3314, NUDOCS 8312070323 | |
| Download: ML20086E473 (1) | |
Text
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VERMONT YANKEE NUCLEAR POWER CORPORATION
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o VERNON. VERMONT oS354 June 26, 1974
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Director
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Directorate of Regulatory Operations, Region I JUN271374
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REFERENCE:
Operating License DPR-28
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Docket No. 50-271 Abnormal Occurrence No. AO-74-09 (24 Ilour Report)
Dear Sir:
As defined by Technical Specifications for the Vermont Yankee Nuclear Tower Otati-... :kction 0.7, we oa wartio;. the ivile in( Abuurral Occurrence as A0-74-09 and confirming our telephone conversation with your office.
At approximately 1200 on June 25, 1974, plant personnel who were performing routine instrument surveillance testing on the Riser d/p LPCI Loop Break Detection Logic discovered that the movements of DPIS 2-1293 and C uere sticking to the extent that the pointer would lag the input pressure by approximately 0.5 psid on increasing and decreasing pressure. This condition was determined to be in violation of Technical Specifications, Section 3.2, Tabic 3.2.1, in that the requirement for the minimum number of operable trip channels per trip system for the A>B d/p Across Risers trip functica was not satisfied.
The plant was operating.
at 80% power at the time of this discovery.
Switch DPIS 2-129B was replaced with an operable spare and. switch DPIS 2-129C was placed in the tripped' condition and will remain that way until another operable spare can be obtained.
8312070323 740703 Very truly yours, PDR ADOCK 05000271 S
PDR VERMONT YANKEE NUCLEAR POWER CORPORATION M SENT M :
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Plant Superintendent Mdh g
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