ML20141F260

Forwards non-proprietary & Proprietary Rept NSPNAD-97002, Steam Line Break Methodology, for Approval of Methodology for Use in Future Analyses & to Remove Dependence on Jco for Restart of Each Unit Following Each Outage.W/Affidavit

ML20141F260
Person / Time
Site:	Prairie Island
Issue date:	06/26/1997
From:	Sorensen J NORTHERN STATES POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML19317C453	List: ML20141F260 ML20141F272 ML20141F277
References
NUDOCS 9707020204
Download: ML20141F260 (2)

Text

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Northern states Power Company 1717 Wakonade Dr. E.

Welch, MN 55089 Tekphone 612-388-1121 l

June 26,1997 U S Nuclear Regulatory Commission Attn: Document Control Desk l Washington, DC 20555 PRAIRIE ISLAND NUCLEAR GENERATING PLANT Docket Nos. 50-282 License Nos. DPR-42 50-306 DPR-60 ,

1 l

l Main Steam Line Break Methodoloav l I

1 in early 1994, NSP was developing new methods for calculating the Prairie Island Main Steam Line Break containment pressure response in anticipation of eventually submitting a license amendment request to reduce the boron concentration in the l boric acid storage tanks. While developing these new methoas, NSP determined I that some assumptions used in previous analyses were non-conservative. NSP  ;

informed the NRC of these findings and prepared a justification for continued I operation which determined that both Prairie Island units could safely continue to operate.

NSP has completed development of the Prairie Island Main Steam Line Break methodology. Attachment 2 to this letter contains a proprietary version of these methodologies and Attachment 3 contains a non-proprietary version. NSP seeks )

NRC approval of the Prairie Island Main Steam Line Break methodology for use in  ;

future analyses and to remove dependence on the justification for continued I operation for restart of each unit following each outage.

The Prairie Island Main Steam Line Break methodologies are considered company confidential, and as such NSP requests that Attachment 2 be withheld from public disclosure pursuant to 10 CFR 2.790(b)(1). The affidavit to support this request is provided as Attachment 1. .

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Page 2 of 2 i If you have any questions related to this submittal, please contact myself or Dale

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Vincent at 612-388-1121. l l

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l Joel P. Sorensen

Plant Manager, l Prairie Island Nuclear Generating Plant j Attachments:  !

l 1. Affidavit Requesting Withholding of Proprietary Information from Public

! Disclosure

! 2. Steam Line Break Methodology, NSPNAD-95002, June 1997, )

l Proprietary Version j Steam Line Break Core Methodology, NSPNAD-95002, June 1997, 3.

Non-Proprietary Version '

4  ;

j c: Regional Administrator-111, NRC

> NRR Project Manager, NRC j Senior Resident inspector, NRC  ;

3 State of Minnesota (without Attachment 2) l

, Attn: Kris Sanda

J E Silberg (without Attachment 2) '

4 4