ML20043H230
| ML20043H230 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 06/14/1990 |
| From: | Fitzpatrick E GENERAL PUBLIC UTILITIES CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9006220272 | |
| Download: ML20043H230 (2) | |
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OPU Nuclear Corporation.
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Post Office Box 388 Route 9 South
'16 Forked River,New Jersey 087310388 i
609 971 4000 c
Writer's Direct Dial Number;
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- U.S; Nuclear Regulatory Commission June 14, 1990 1
Attne Document Control Desk I
Washington,;D.C.; 20555
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Dear Sir 1
L Subjects Oyster Creek Nuclear Generating. Station Y
Docket No. 50-219 g
Diesel Generator Switchgear JM(
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On June 13, 1990,'at 4:15 p.m., a conference call was conducted between GPU p
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. Nuclear personnel at the Oyster Creek site as well as the Parsippany Corporate p'
Haadquarters, and NRC personnel at the Oyster Creek sito,. Region I Headquarters
' arid the Of fice of Nuclear Reactor, Regulation in Washington DC.
The call was T
.placed to discuss the seismic capability of the. Diesel Generator Switchgcar.
Eh s7 iV (A material'non'onformance had been identified in the diesel generator switchgear.
c jj The original vendor drawings indicated that anchor bolts had been installed to F [N secure the switchgwar'to=the Diesel Building floor.
A physical walkdown i
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- determined thtt the anchor
- bolts had not been installed.- This placed the as-found
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) seismic.acceptiability of the. diesel generator 'switchgear < in question, ws
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ly While experienco data has demonstrated that unanchored. equipment can slide and/or tilt during a seismic event,Llt hao also dt.monstrated that unanchored equipment
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3 has the ability to ' resist nome level of solomic input without experiencing '
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meantngful movement. To determine the capability of the diesel generator qi switchgear to survive an earthquakei a conservativa' analysis was performed by d -a i
. GPUN.a. This analysiu' considered the inheaant flexibility of the nwitchgear and the 4
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f iriction forces between the switchgear supports nnd the concrete floor.
A' factor
- of' safety of 4l was Lutilized to account ;for dynamic affecta of shifting masces.
f[3 y' ;This calculation demdpstrated that:the ewitchgear isi able to resist niiding during
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Thiu cciculat. ion alsoidemonstrhtes that overturning will not' occur i an earthquake of a nNnitudefoi at least.11g which is equivalent to the OBE at 3
Oyster Creek.
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at earthquths levels!of the magnitude of the?SSE.
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'catailed finite element calculationsihave been peNormed ingthe past which
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- demonstrate ne'emic adequacy'of other equipment. designed'not to be anchoredi(spent A fuel' pool racks,(for exatople). These calculations demonstrate that dun to the y;x UL c6ntent and' duration'of earthquake' motion, unanchored components have.significant
%J.y capabilit.y to resist sliding and overturning. l n additLon, cables and ccnduit QW.1 whic'h are( attadhed. to the owitchgear a?.a ; capable of withstanding scos level of.
h d, force without loss.o f funct. ton. The uupportat for'the 4160V switengear; consist of i
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4 channelo running the full lengt'n of the switchge d..
The majority ofcthe mass is j
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, located'in.the center..
This ccnt'iguration makes sliding less likely due to the: '
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,skabilining effe'ets o'f tho outdr two sup; ort channels.
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M 900622027d'9(C614
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PDR ADGCK O W O219 c
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GPU Nacles Corporahonis a aubs,ciarypf the GenetalPubhcd:ihh9s Corpotut:on E
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' If a finite element model of the swithchgear were developed which accounted for.
I the factors listed above, and if a time history input were applied to the model, it is highly-likely that the switchgear could be demonstrated to sursEve the.165g SSE earthquake evaluated by the SEP.
Therefore, the diesel gener9 tor switchgear was determined to be operable.
The purpose of thin letter is to document the GPUM commitment to improve the seismic restraints for the diesel generator switchgear unclosures.
During the j
refernced telecon,.GPUN stated that the engineering would be finalized and-the modifications completed prior to June 22, 1990. The NRC agreed that the j
seismic analysis and schedule for implementation were acceptable.
If there should be any further questions, please contact Mr. George Busch, Oyster Creek Licensing Manager at: 609-971-4643.
L Very truly yours, o
A E.E. Fitzpa ick Vice President and Director
!1 Oyster Creek j-EEF/JJR jc
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L (JR-LTRS2) 7 cc:
.Mr. Thomas Martin, Administrator Reflon 1 J
U.S. Nuclear Regulatory Commission 475 Al'lendale Road King of Prussia, PA 19406 l
r NRC Prisident. Inspector
'I Oystur Creek Huclear Genet:ating Stntion Mr. A.lexander Dromerick U.S. Nuclear 'degulatory Commission.
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. Mail Station P.1-137
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Washington, DC.20555 l
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