ML20195H758

Submits Rev of Licensee Commitment Made in Response to Unresolved Items Re Insp Rept 50-298/97-18.Util Will Complete 125 Vdc Load & Voltage Studies by 981204.Commitment Made by Util,Encl

ML20195H758
Person / Time
Site:	Cooper
Issue date:	11/20/1998
From:	Swailes J NEBRASKA PUBLIC POWER DISTRICT
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
50-298-97-18, NLS980191, NUDOCS 9811240089
Download: ML20195H758 (3)

Text

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. 2 Nebraska Public Power District Nebraska's Energy Leader l

l NLS980191 i November 20,1998 l U.S. Nuclear Regulatory Commission l Attention: Document Control Desk  !

Washington, D.C. 20555-0001 Gentlemen:

Subject:

Revision of Commitment Made in Response to Unresolved Items Cooper Nuclear Station, NRC Docket 50-298, DPR-46

Reference:

1. Letter to U. S. Nuclear Regulatory Commission from P. D. Graham (NPPD) dated January 15,1998," Follow-up Information Relative to Unresolved Items Identified in NRC Inspection Report 97-1 S"

2. Letter to G. R. Hom (NPPD) from A. T. Howell III (USNRC) dated December 17,1997,"NRC Inspection Report 50-298/97-18"

3. Letter to U.S. Nuclear Regulatory Commission from J. H. Swailes (NPPD) dated August 17,1998," Revision of Commitment Made in Response to l Unresolved Items" l

By letter dated January 15,1998 (Reference 1), responding to a Nuclear Regulatory Commission (NRC) Inspection Report (Reference 2), Nebraska Public Power District (District) committed to revise the 125 Vdc load and voltage studies by August 31,1998. In Reference 3 the District revised the date when this commitment would be complete to November 20,1998. Due to i b k unforseen emergent issues with the calculations and the present refueling outage, . dDf the 12l 0 a. load and voltage studies will not be fully complete until December 4,1998.

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@; The principal elements of the studies have been completed. The activities performed included: i 1

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= . Separating the single scenario mto individual scenarios specific to the requirements being 4< addressed, 3

= ' Validating and documenting the basis for the sequencing of events in eac! scenerio,.

Cooper Nudear Station PO. Box 98/ Brownville. NE 68321D098 ,

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, ,'4t ' Telephone:(402) 825 38H / Fax: (402) 825 S2n brtp //www nppd com l

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j. '.. .g NLS980191  ;

Page 2 Using the calculated load currents to provide the basis for the battery service test load profiles, ,

. Using the calculated voltages to provide the basis for service test acceptance criteria previously lacking in surveillance procedures, and O .

Validating a representative sample of circuits to assure a high level of confidence in the inputs to be used (the sample size was expanded during the study to include redundant i

circuits to those where adverse anomalies were noted). l The results of this work have confinned that the presumptions made in the November 1997 operability assessment remain valid. Consequently, the battery remains capable of performing its i safety function.

The last step of the process, which is primarily administrative in nature, involves revision of the L District's ' supporting calculations to incorporate the results of the 125 Vdc load and voltage studies. This will be accomplished no later than December 4,1998.

Should you have any questions concerning this matter, please contact me.

Sincerely, V

.S iles Vice Pre.;ident o 'uclear Energy ,

cc: Regional Administrator USNRC - Region IV

Senior Project Manager USNRC - NRR Project Directorate IV-1 Senior Resident Inspector -

USNRC 1 '

' NPG Distribution .

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ATTACHMENT 3 LIST OF NRC COMMITMENTS l l

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Correspondence No: NLS980191 The following table identifies those actions committed to by the District in this document. Any other actions discussed in the submittal represent intended or i They are described to the NRC for the NRC's

\ planned information actions and are by thenot District.

regulatory commitments. Please notify the NL&S Manager at 1

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Cooper Nuclear Station of any questions regarding this document or any associated j

regulatory commitments.

l COMMITTED DATE COMMITMENT OR OUTAGE --

1 CNS will revise the 125 Vdc load and voltage studies. December 4, 1998 l

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1 l' iAOCEDURE NUMBER 0.42 l REVISION NUMBER 6 l PAGE 9 OF 13 l