ML20063Q124

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Provides Supplemental Info for 900115 Tech Spec Change Request Re Max Allowable Control Rod Drop Time.Retained DNBR Margin Tracked & Documented by Calculational Note
ML20063Q124
Person / Time
Site: North Anna  Dominion icon.png
Issue date: 08/15/1990
From: Stewart W
VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
89-795A, NUDOCS 9008200061
Download: ML20063Q124 (2)


Text

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.a VIHOINIA I$1.1 CTWIC AND POWP.M COMPANY Rienwown,VNotwsA utsuel August 15,1990 U.S. Nuclear Regulatory Commission Serial No.:

89 795A Attention: Document Control Desk NL&P Washington, D.C. 20555 Docket Nos.: 50 338 50 339 License Nos.: NPF 4 l

NPF 7 Gentlemen:

VIRGINlA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNITS 1 AND 2 SUPPLEMENTAL INFORMATION FOR l

ANGE REQUEST REVISED CONTROL ROD DROP TIME On January 15,1990, Virginia Electric and Power Company requested amendments, in the form of changes to the Technical Specifications, to Operating License Numbers NPF 4 and NPF 7 for North Anna Power Station Units 1 and 2, respectively. These requested amendments support the introduction of a new Westinghouse (VANTAGE SH) 17X17 fuel assembly. The requested change to the Technical Specifications involved a change to the maximum allowable control rod drop time.

A discussion between Virginia Electric and Power Company and the NRC regarding l

this Technical Specification change request was conducted by telephone on August 3, L

1990. Questions were asked regarding the method used by Virginia Electric and l

Power Company to track retained DNBR margin. As explained during the discussion, l

retained DNBR margin is tracked and documented by calculational note; calculational notes are uniquely identified and retained as OA records.

The Thermal / Hydraulics (T/H) Evaluation calculational note is prepared as part of the reload safety evaluation process, in this calculational note, the DNBR results of the UFSAR transients which may be affected by the reload core design aro evaluated.

The calculational note also presents a discussion of available retained DNBR margin and applicable penalties, as well as tables of retained DNBR margin.

4 Because DNBR analyses have been performed under a variety of methodologies, conditions, and assumptions, the retained margin tables have been organized according to the methodology and DNBR correlation assumed in the DNBR analysis.

For those transients explicitly reanalyzed with the increased bypass flow and increased rod drop time associated with the Vantage 5H fuel product, additional tables of retained DNBR margin have been created. As analyses and methods evolve, the retained margin tables will be updated and modified.

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l If you have any questions or require additional Information please contact us immediately.

Very truly yours, l

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. L. Stewart Senior Vice President - Nuclear cc:

U.S. Nuclear Regulatory Commission Region ll 101 Marietta Street, N.W.

Suite 2900 Atlanta, Georgia 30323 i

Mr. M. S. Lesser NRC Senior Resident inspector North Anna Power Station Commissioner Department of Health Room 400 109 Governor Street Richmond, Virginia 23219 l

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