ML19250A532

LER 79-023/03L-0:on 790919,LPCI Loop cross-tie Line Hanger Found Inadequate to Support Design Load.Caused by Improper Installation.Review of All Seismic Class I Sys Underway. Hanger Repaired W/New Anchor Bolts

ML19250A532
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	10/17/1979
From:	Conway W VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19250A526	List: ML19250A525 ML19250A532
References
LER-79-023-03L, LER-79-23-3L, NUDOCS 7910230600
Download: ML19250A532 (2)

Text

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NAME OF PREPARER

y VTVYS1 05000271 LER 79-23/3L EVENT DESCRIPTION AND PROBABLE CONSEQUENCES During the continuing investigation to determine the adequacy of all Seismic Class I hangers, as described in NRC Bulletin 79-02, RHR-II-16 was determined to be inadequate to support its design load. This hanger is located in the LPCI loop cross-tie line. Tech. Spec. S 2ct ion 3.6. I.1 re-quires all safety-related snubbers to be operable during power operation.

This Tech. Spec. Section was determined to be appropriate, via RO 79-15/3L, since a seismic hanger performs a similar service as a snubber. As allowed by Tech. Spec. Section 3.6.I.2, the hanger was repaired within the 72-hour time period. A similar occurrence was reported to the Com-mission as RO 79-15/3L.

CAUSE DESCRIPTION AND CORRECTIVE ACTIONS The cause of this occurrence is improper installation during con-struction. In accordance with NRC Bulletins 79-2 and 79-14, a complete review of all Seismic Class I systems is underway. This review includes a verification of design loads and support adequacy. Appropriate modifi-cations, if any, will be performed after the reanalysis is completed. In the interim, the hanger was repaired including the installation and veri-fication of new anchor bolts. The original hanger was designed and built by ITT Grinnel Corp.

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