ML20092A352

Forwards Response to Generic Ltr 91-11, Resolution of Generic Issues 48 'Lcos for Class 1E Vital Instrument Buses' & 49 'Interlocks & LCOs for Class 1E Tie Breakers.'

ML20092A352
Person / Time
Site:	Cooper
Issue date:	01/31/1992
From:	Horn G NEBRASKA PUBLIC POWER DISTRICT
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-GTECI-048, REF-GTECI-049, REF-GTECI-NI, TASK-048, TASK-049, TASK-48, TASK-49, TASK-OR GL-91-11, NSD920108, NUDOCS 9202100074
Download: ML20092A352 (3)

Text

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NSD920108 January 31, 1992 U.S. Nuclear Regulatory Connission Attention: Document Control Desk Vashington, DC 20555

Subject:

Response to NRC Ceneric Letter 91 11 Resolution of Generic Issues 48, "LCO's for Class 1C Vital Inst rument Buses," and 49, ' Interlocks and LCO's for Class IE Tie Breakers" Cooper Nuclear Station NRC Docket No. 50 298, DPR 46 Centlemen:

NRC Ceneric Letter (CL) 91-11, *LCO's for Class IE Vital Instrument Buses and Interlocks and LCO's for Class IE Tie Breakers", was issued on July 18,1991 and received by Nebraska Public Power District (District) on August 5, 1991. The Generic Letter contained reconnended actions f or the Resolution of Generic Issues 48 ("LCO's for Class 10 Vital Instnument Buses"), and 49 (Interlocks and LCO's for Class 1E Tic Breakers").

As requested in the Cencric Letter 'he D! s,t ric t has investigated and ensured that the Cooper Nuclear Station (CN crocedures address tiine limitations and surveillance requirernents for vital instrumentation buses, and inverters or other onsite power sources that supply the vit al instrument buses (Generic Issue 48).

In addition the District has investigated the vital instrument buses and redundant Class IE buses relative to prob 1cas which could be created by the tie breakers. We have verified that CNS has no tie breakers of the type discrised in the Generic Letter, as clarified by the attached telephonic conversation with the NRC staff, that can connect normally independent , redundant Class IE AC and DC buses, As such, the concerns of Generic Letter 91 11 do not apply to Cooper Nuclear Station.

This response is submitted under oath in accordance with the provisions of 10CFR50.54(f).

Please contact us if you have any questions.

Sin"erely, CD /-

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C . dt .) Ho rn C%.

58 Nuclear Power Group Manager bU CRS:tja:CL91 11.res y Attachment I

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k NRC Resident Inspector Cooper Nuclear Station i

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I-liSD920108 PaSe 2 January 31, 1992 STATE OF NE!'RASKA

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C. R. llorn, being first duly sworn, deposes and says that he is an authorized representative of the Nebrcaka Public Power District, a public corporation and political subdivision of the State of Nebraska; that he is duly authorized to submit this information on behalf of Nebraska Public l'ower District; and that the statements contained herein are true to the best of his knowledge and belief.

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G. R. llorn Subscribed in my presence and sworn to before ne .. i s 3/O I day of l!h 0Afld , 1992.

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, ,' NEDPWSKA PUSUC POWCM Da$TFUCT Cheet 101 1 j RECORD OF TELEPHONE CO8&t;nSA110N Date JAN9. W Time 0910 CST rMoM: 10; Name: R. Poust, n. Moberty. M. Dean Name: O.Cropra Cortynny: NPPD . CNS Cornpartf. NRC War.hhgtort DC i pygVCCT: Generic Letter 9111 DMek. mat Bus Tie B*ookers art CNS (NSD92Wnp]

TortCS OF Cot #EASAfloN:  :

Mr. Chopro was corvented to provue addhbral infortfation to ad in dettemining 11 CNS had bus De Latiners as that term la used in the Generic t.etter. (Mr. Chopra was toted as the NRC Infortnation contact in the Generic Letter.)

Alcit roust asked the folicmring questbns:

0: In regards to Ltw definition of bus sie breaker, the CNS contiguration tas dMar nal DC panate arid AC MCCs tint can be transferrtd fmm 1 of 2 OMelons to the other dMslonal power source using a shgte transfet switch. This la exwmmty done during plant outagua. This does not allow botgDC dMabns to connoff 0j togtKher at the aarne tirne g gg& r(44lN A: Because th'4 configuratlan carviot Ife two rodurdsarst busses together at the name time, this would rot be consbered to be a lxis tie breaker [as used in the Gentulo Letter).

Q: in the itG VDC battery systems, CNS can idaos the *A' bus on the *B' battery. This is done with t eingle transfer switch.

A: This is not in the name category of tie bruakeers that we are conterrebd about h this Gen 8rlC LOUor.

C. CNG oan also transler loads on an 'A' [1th VDC) panel to the *B* battery but. In this esse, al of the

'A' dMalonal loada for ttat paruel would ther be on the *0' descnal bus. This is done with a transtta swtch (Of t'ot panel.

(Mr. Chopra reuvented thst a simple' drawing of this example be sont to him so tiet he could evaluate ft better. Two skutahes were sent to him, arvi he callod H6ck later in the day.]

A: This is tot a configuratksn lo wtSch the concoms of the Genotic lettor spply,

}1:6Jhh ~ Y'Y Michael A. Dean, PE

! Nuclear Ucensing in.1 tafely Supervisor l

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