ML20199L441

Forwards Safety Evaluation Re Util 860110 Projected Values of Matl Properties for Fracture Toughness Requirements for Protection Against Pressurized Thermal Shock Events.Response Acceptable

ML20199L441
Person / Time
Site:	Prairie Island
Issue date:	06/23/1986
From:	Lear G Office of Nuclear Reactor Regulation
To:	Musolf D NORTHERN STATES POWER CO.
Shared Package
ML20199L446	List: ML20199L441 ML20199L449
References
REF-GTECI-A-49, REF-GTECI-RV, TASK-A-49, TASK-OR TAC-59974, TAC-59975, NUDOCS 8607090415
Download: ML20199L441 (3)

Text

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JUN 2 31986 Docket Nos. 50-282 Mr. D. M. Musolf, Manager Nuclear Support Services Northern States Power Company 414 Nicollet Mall Midland Square, 4th Floor Minneapolis, Minnesota 55401

SUBJECT:

PROJECTED VALUES OF MATERIAL PROPERTIES FOR FRACTURE TOUGHNESS REQUIREMENTS FOR PROTECTION AGAINST PRESSURIZED THERMAL SH0CK EVENTS PRAIRIE ISLAND NUCLEAR GENERATING PLANT UNIT NO. 1 We have reviewed your letter dated January 10, 1986 which were submitted in response to the Pressurized Thermal Shock (PTS) Rule, 10 CFR 50.61 for the Prairie Island Nuclear Generating Plant, Unit No. 1. We have found the material properties of reactor vessel beltline materials, the projected fluence at the inner surface of the reactor vessel at the expiration date of the license and the calculated RT at the expiration date of the license, June 25, 2008, tobeacceptable.PTkhecalculatedRT is below the screening criterion of 300 FforcircumferentialweldmSIhrialatthe expiration date of the license. This meets the requirements of the PTS rule.

We note that you have applied for an amendment to extend your license for Prairie Island Nuclear Generating Plant Unit No. 1 and you have provided information to support operation of your plant to the proposed expiration date of the license without exceeding the PTS screening criteria. We did not deal with this issue in our evaluation since this issue will be addressed in the evaluation of your proposed amendment to extend the expiration date of your license.

The PTS Rule requires that the projected assessment of the RT must be updatedwheneverchangesincoreloadings,surveillancemeasuNkentsorother information (including changes in capacity factor) indicated a significant change in the project values. This ensures that the licensees will track the fluence at the limiting beltline materials throughout the life of the plant to verify their assumptions. In this regard we request you to submit a gDR607090415 860623 p ADOCK 05000282 PDR

-2 re-evaluation of the RT and comparison of the predicted value with future Pressure-Temperaturesubbkttalswhicharerequiredby10CFR50,AppendixG.

This completes our review of the PTS issue for your plant. Our associated Safety Evaluation is enclosed.

1 George E. Lear, Director PWR Project Directorate #1 Division of PWR Licensing-A

Enclosure:

As stated cc: w/ enclosure See next page i

Office: L PA 1 PM/ PAD #1 PB PD/ PAD #1 Surname:

Date:

PSh tieworth 06/ 86 DDilanni:iil 06/ /J /86 06// /86 s'ing Glear h 06p/86

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Mr. D. M. Musolf Prairie Island Nuclear Generating Northern States Power Company Plant cc:

Gerald Charnoff, Esq.

Shaw, Pittman, Potts and Trowbridge 1800 M Street, NW Washington, DC 20036 Executive Director Minnesota Pollution Control Agency 1935 W. County Road, B2 Roseville, Minnesota 55113 Mr. E. L. Watzl, Plant Manager Prairie Island Nuclear Generating Plant Northern States Power Company Route 2 Welch, Minnesota 55089 Jocelyn F. Olson, Esq.

Special Assistant Attorney General Minnesota Pollutior. Control Agency 1935 W. County Road, B2 Roseville, Minnesota 55113 U.S. Nuclear Regulatory Comission Resident Inspector's Office Route #2, Box 500A Welch, Minnesota 55089 Regional Administrator, Region III U.S. Nuclear Regulatory Comission Office of Executive Director for Operations

) 799 Roosevelt Road Glen Ellyn, Illinois 60137 Mr. William Miller, Auditor Goodhue County Courthouse

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Red Wing, Minnesota 55066 I

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