ML19257A294

Provides Addl Info Re Deficiency Discovered on 791207 Concerning Potential Nonconservative Feature of Large Break LOCA-ECCS Evaluation Model.Reanalysis Performed Using Heatup Rate Dependent Rod Burst Calculation Procedure

ML19257A294
Person / Time
Site:	North Anna
Issue date:	12/11/1979
From:	Brown S VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
REF-PT21-79-182-000 NUDOCS 8001030583
Download: ML19257A294 (2)

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VIRGINI A ELECTRIC AND POWER COMP ANY, RICHMCND, VIRGINI A 23261 r - ,7 ;Dechnfdr 11, 1979 Mr. James P. O'Reilly, Director Serial No. 1118 Office of Inspection & Enforcement PSE&C/JCHjr:mac: wang U.S. Nuclear Regulatory Comission Region II Docket No. 50-339 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303

Dear Mr. O'Reilly:

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On December 7,1979 a report was made under the provisions of 10CFR50.55(e) concerning the Loss of Coolant Accident (LOCA) - Emergency Core Cooling System (ECCS) Evaluation Model.

In accordance with the reporting requirements of 10CFR21, the following information is submitted:

A. Name and address of reporting individual:

Mr. E. A. Baum, Executive Manager Licensing and Quality Assurance -

Virginia Electric and Power Company P. O. Box 26666 Richnlond, Virginia 23261 B. Facility, activity and/or component affected:

- North Anna Power Station, Unit 2 LOCA - ECCS Evaluation Model C. Name of firm constructing the f acility or supplying the component, activity or service:

Westinghouse Electric Corporation P. O. Box 355 Pittsburgh, Pennsylvania 15230 D. . Description of defect, deficiency, or failure to comply:

A potential nonconservative feature'of the large break LOCA-ECCS evaluation medel exists. This problem could affect the peak clad temperature calculated for the large break LOCA transient. The FQ limit may be affected.

E. Date of determination of reportability: -

December 7, 1979 l66[ g 34[( Yhf i

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8001030 d.g O ' M GM '

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Similar components, activities, or services:

North Anna Unit 1 G. Corrective action which has been, is being or will be taken, the individual responsible and the length of time to complete the action:

A reanalysis was performed using the Westinghouse February 1978 evaluation model and an appropriate heat up rate dependent rod burst calculation procedure. The analysis was submitted by Vepco (C. M.

Stallings) to the NRC (H. R. Denton) letter, Serial No. 986, dated November 29, 1979. A proposed FQ limit modification was submitted.

H. Other information:

None Any information not avai.lable at this time will be submitted in a follow-up letter as a 30-day report.

Should you require further information, please contact this office.

Very truly yours, kY.V /. Y ju--g Sam C. Brown, Jr.

Senior Vice President - Power Station Engineering and Construction cc: Director, Office of Inspection and Enforcement (3) 166734(b 4

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