ML19305D794

LER 80-017/01T-0:on 800326,reanalysis of Seismic Pipe Stress of Main Steam Piping Inside Valve House for OBE long-term Criteria Showed,For Some Conditions,Allowable Stress Level May Be Exceeded in Headers for Main Steam Relief Valves

ML19305D794
Person / Time
Site:	Beaver Valley
Issue date:	04/08/1980
From:	Werling J DUQUESNE LIGHT CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19305D782	List: ML19305D781 ML19305D794 ML19305D797 ML19305D809
References
LER-80-017-01T, LER-80-17-1T, NUDOCS 8004150529
Download: ML19305D794 (2)

Text

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NRC FCO.#. 366 U. S. NUCLEAR REGULATORY COMMISSloN (7 77) 1.tcENSEE EVENT REPORT CONTROL stocx: l l l l l l l@ iPtEAsE PRINT OR TYPE ALL REQUIRED INFORMATION) l l lo j i j l P l A l 3 l V l S l 1 l@l 0 l0 l- l 0 l 0 l 0 l 0 l 0 l- l0 l .s0 l@l4 l1  ;.

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I 8 el QOCK ET NwYSER EVENT CESCRIPTION ANO PROB ABLE CONSEQUENCES h O I2l l The reanalysis of the seismic pipe stress of the main steam piping inside the l gl valve house for the OBE long term criteria indicates that for certain load l l o 14 l l conditions the code allowable stress level may be exceeded in the headers that l 10 I s l I support the main steam safety relief valves. When the safety relief blowdown loads l ,

f5Ts 1 l are combined with the OBE, pressure and dead load stresses, the computer code i l o 171 l allowabic stress icvel of 1.25h is exceeded in the headers. The reanalysis of the I

!olal I remainder of the main steam piping inside the valve house (continued on attached) l 60 7 8 9 COMP. VA LV E Sv5 TEM CAUSE CAUSE i C00E CODE SUSCODE COMPONENT CO DE SUSCCOE SUSCCCE i

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9 10 18 52 13 18 19 20 SE QUENTI AL OCCURAENCE REPORT REVISloN I

EVENTYEAR REPORT NO. COCE TYPE No.

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43 44 4; CAUSE CESCRIPTION AND CORRECTIVE ACTIONS @

lilo g ] The original calculations of record which qualified the headers were reviewed.and l l

gl it was determined that the safety relief blowdown loads had -been considered in a l

,,2j l local stress calculation using the PITRUST omputer code but had not been (

, 3 l considered in the Equation 9 analysis. The FSAR (Response to Question 3.23, I

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i 4 l Amendment 1, 4/23/73) indicates that both the PITRUST and tcontinued on attached) I 80 7 8 9

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• . POWE R CTMER STATUS 35 0 RY DISCOVERv OESCRIPTION N/A l i s l Xl@ l 0 l 0 l 0 l@l" "

l lDi@lNotificationfromA/E l ACTiviTv Co'0 TENT l AA10UNT OP ACTIVITY LOCATION CP RELEASE N/A N/A l 7

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@D OP mELEASE 13 l 44 l l 45 80 PERioNNEL EXPOSURES i NUUSER ?vPE DESCRIPTICN t N/A l I'iTTi l 01010 l@l z i@l 'd PEasoNNE L imau'dits NUveER otsCRiPTioNh I T 1 I o l o ! o !@l12 s/A l go 7 8 9 18 LOSS OP CR OAVAGE TO P ACILtTY TvPE C E SC Rt* TION N/A l t 7 8 9 8 9 W @l 10 80 NRC USE ONLY ,

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412-643-1258 2 NAME OF PREPARER 800.4150520

a Attachment To LER 80-17/01T Beaver Valley Power Station Duquesne Light Company Docket No. 50-334 Event Description And Probable Consequences (continued) for the OBE case is still in progress. Since the plant is shutdown for refueling and maintenance, there is no potential safety hazard existing.

Cause Description And Corrective Actions (continued)

Equation 9 tests must be met, which was not done. The comparison equations are being completed at the present time.

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