ML19256F318

LER 79-034/01P-0:on 791211,during Seismic Analyses of Seismic Class 1 Pipe Supports,Discovered That Pipe Supports in Portion of Two Sys May Not Support Seismic Loads.Caused by Incorrect Design or Application of Supports

ML19256F318
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	12/12/1979
From:	Conway W VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19256F316	List: ML19256F315 ML19256F318
References
LER-79-034-01P, LER-79-34-1P, NUDOCS 7912180489
Download: ML19256F318 (2)

Text

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.. . LlCENSEE EVENT REPORT LF.R 79-34/1P (Ps. EASE PRINT OR TYPE ALL REQUIRED INFORMATION)

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REPORT DATE 7 8 60 61 OOCKET NUMBER 68 69 EV ENT OATE EVENT DESCRIPTION AND PROBABLE CONSECUENCES h a 2 l o 3 l See attached sheet I I

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41 lY l@ l43A l@ lI l2 l0 l7 [@ 47 33 34 35 36 40 42 44 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS i o 1 The cause of this event is the incorrect desien or application of pipe supports to l 1 i neet the design loads required bv the olant seismic analysis. Aporopriate modifi- l 1

2 1 cations to the subieet pipe suonort systems will be performed to insure that the l l systems meet the recuirements of our seismic analysis. Additional analysis of this [

1 3 i 4 1 occurrence will be orovided in the 14-day report.

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$A  % POWER OTHER STATUS 01 RY OISCOVERY OESCRIPT10N 32 1 s [3_j@ 0 l 9 l 9 l@l NA l l C l@l Investigation relating to NRC Bull. 79-14 ACTivtTY CO TENT AMOU~T O, ACTiviTv @ tocATiON O REtEuE @

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7 i a 8 9 10 l 0 0l@l 11 12 NA 80 LOSS OF OR OAMAGE TO PACILITY O TYPE r ISCRIPTION b 7

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• VTVYS1 05000271 LER 79-34/1P EVENT DESCRIPTION AND PROBABLE CONSEQUENCES During the continuing seismic analyses to determine the adequacy of all Seismic Class I pipe supports, as required by an NRC letter from Mr. Boyce H. Grier to Mr. Robert H. Groce dated October 24, 1979, and NRC Bulletin 79-14, it was discovered that pipe supports in a portion of two systems may be inadequate to support their seismic loads. In conjunction with those identified in RO 79-33/IP, the total number of systems affected is six. In accordance with this letter, all modifications required by this occurrence will be completed within seven days or the plant will be brought to a cold shutdown condition. Engineering evaluations associated with the identified supports have determined that system components are not considered inoperable. Previous analytical failures of pipe supports were rr eorted to the Consission as RO 79-33/lP.

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