ML20217E264

Forwards RAI Re Plant Revised MSLB Containment Pressure Response in Anticipation for License Amend Request to Reduce Boron Concentration in Boric Acid Storage Tank

ML20217E264
Person / Time
Site:	Prairie Island
Issue date:	09/26/1997
From:	Wetzel B NRC (Affiliation Not Assigned)
To:	Richard Anderson NORTHERN STATES POWER CO.
References
TAC-M99109, NUDOCS 9710060422
Download: ML20217E264 (3)

Text

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Mr. Roger O. Anders:n, Direct:r September 26, 1997 Liccnsing cnd M:nagement Issues Northern St:t:s Pcwer Comp ny 414 Nicollet Mall Minneapolis, Minnesota 55401

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION ON THE PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNITS 1 AND 2, REVIEW OF MAIN STEAM LINE BREAK METHODOLOGY (TAC NOS, M99108 AND M99109)

Dear Mr. Anderson:

By letter dated June 26,1997. Northern States Power Company (NSP) submitted for staff review a plant specific topical report of the revised main steam line break containment pressure response in anticipation for a license amendment request to reduce the boron concentration in the boric acid storage tanks. As part of our continued review efforts of your request, the staff requires some additional information. Our request for additional information (RAl) is enclosed.

Please provide your response within 90 days of the date of this letter to support our review of this report if you have any questions regarding the content of the RAI, please contact me at (301) 4151355.

Sincerely, d .

Beth A. Wetzel, Senior Project Manager Project Directorate 1111 Division of Reactor Projects - Ill/iV Office of Nuclear Reactor Regulation Docket Nos. 50-282, 50 306

Enclosure:

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6 Mr. Roger O. Anderson, Director Prairie island Nuclear Generating Northem States Power Company Plant oc:

J. E. Silberg, Esquire Site Licensing Shaw, Pittman, Potts and Trowbridge Prairie Island Nuclear Generating 2300 N Street, N. W. Plant Washington DC 20037 Northem States Power Company 1717 Wakonado Drive East Plant Manager Welch, Minnesota 55089 Prairie Island Nuclear Generating

- Plant Tribal Council Northem States Power Company Prairie island Indian Community 4 1717 Wakonade Drive East ATTN: Environmental Department  !

Welch, Minnesota - 55089 - 5638 Sturgeon Lake Road Welch, Minnesota 55089 Adonis A. Noblett Assistant Attomey General '

Office of the Attomey General 455 Minnesota Street Suite 900 St. Paul, Minnesota 55101 2127 U.S. Nuclear Regulatory Comr$1ssion Resident inspector's Offica 1719 Wakonado Drive East Welch, Minnesota 55089 9642 j Regional Administrator, Region I!I U.S. Nuclear Regulatory Commission 801 Warrenville Road Lisle, lilinois 60532-4351 Mr. Jeff Com, Auditor / Treasurer Goodhue County Courthouse Sox 408 Red Wing, Minnesota 55066-0408 Kris Sanda, Commissioner Department of Public Service 121 Seventh Place East Suite 200 St. Paul, Minnesota 55101 2145 November 1W

, REQUEST FOR ADDITIONAL INFORMATION REVIEW OF STEAM LINE BREAK METHODOLOGY TOPICAL REPORT FOR PRAIRIE ISLAND UNITS 1 AND 2

1. Paragraph 4.2 of NSPNAD-97002,' Steam Line Break Methodology," indicates that steam generator (SG) tube height was modoled to be very small in order to force flashing of feedwater added to the broken SG. Elaborate on the thermal heat transfer used in the model and its effects of the total mass and energy release with respect to the amount and timing.

2. Paragraph 7.1.1 of NSPNAD 97002 describes a benchmark case for which the i

peak containment pressure is 68.9 psia. However, paragraph 7.2.1 describes a l limiting containment pressure case for which the peak pressure is 60.0 pela.

l Explain why the 68.9 psis case is not considered the limiting case.

l 1

Enclosure

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