ML20097J434

Proposed Tech Specs,Modifying Table 3.2-1 of TS 3.2.5 to Increase Minimum Allowable RCS Total Flow Rate from 284,000 Gpm & 275,000 Gpm to 295,000 Gpm

ML20097J434
Person / Time
Site:	North Anna
Issue date:	01/30/1996
From:	VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
Shared Package
ML20097J432	List: ML20097J428 ML20097J434
References
NUDOCS 9602020141
Download: ML20097J434 (5)

Text

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-> TABLE 3.2-1

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3 Loops in & Loop Stop. & Isolated Loop PARAMETER Operation Valves Open Stoo Valves Closed Reactor Coolant System Tavs s591 F i

Pressurizer Pressure 2 2205 psig

• Reactor Coolant System 2 295,000 gpm l

to Total Flow Rate 3;:

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u Limit not applicable during either a THERMAL POWER ramp increase in excess of 5% RATED THERMAL POWER per minute or a THERMAL POWER step increase in excess of 10% RATED THERMAL POWER.

Values dependent on NRC approval of ECCS evaluation for these conditions.

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u. 2 Loops in Operation ** - 2 Loops in Operation **

3 Loops in & Loop Stop & Isolated Loop PARAMETER Operation Valves Open Stoo Valves Closed Reactor Coolant System Tavs 5;591 F Pressurizer Pressure 2 2205 psig

• Reactor Coolant System 2 295,000 gpm w l Total Flow Rate R

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E Limit not applicable during either a THERMAL POWER ramp increase in excess of 5% RATED THERMAL POWER per minute or a THERMAL POWER step increase in excess of 10% RATED THERMAL POWER.

Values dependent on NRC approval of ECCS evaluation for these conditions.

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p ATTACHMENT 3 l .

l i SIGNIFICANT HAZARDS CONSIDERATION i

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d VIRGINIA ELECTRIC AND POWER COMPANY j

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SIGNIFICANT HAZARDS CONSIDERATION The proposed Technical Specifications change increases the minimum allowable RCS Total Flow Rate from 284,000 gpm (Unit 1) and 275,300 (Unit 2) to 295,000 gpm (Units 1 and 2).

The RCS flow rate is an assumption in safety analyses, affecting UFSAR Chapter 15 transient analyses, Reactor Core Safety Limits (RCSLs), and thermal overtemperature and overpower AT protection functions.

An increase in the minimum RCS flow rate limit generates a benefit for safety analyses which have a DNBR acceptance criterion. For other safety analyses which are limited by considerations such as heat sink or pressurization criteria, an increased RCS flow rate limit is either a benefit, or the event is insensitive to RCS flow rate. The existing safety analyses are analyzed for a lower RCS flow rate limit, and are bounding with respect to expected actual plant behavior and to analyses at the proposed RCS total flow rate.

Therefore, no reanalyses are required to support the proposed Technical Specifications change.

Virginia Electric and Power Company has reviewed the proposed changes against the criteria of 10 CFR 50.92 and has concluded that the changes, as proposed, do not pose a significant hazards consideration. Specifically, operation of North Anna Power Station in accordance with the proposed Technical Specifications changes will not:

1. Involve a significant increase in the probability or consequence of an accident previously evaluated.

The probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated in the safety analysis report would not increase. The proposed Technical Specifications change only increases the minimum allowable RCS total flow rate in the applicable Limiting Condition of Operation. No other changes are being made to allowable operating conditions defined by Technical Specifications, procedures, or to any plant design feature by the implementation of this change. There is no impact on the actual plant performance. Changes in the assumed initial conditions for the accident have no bearing on the probability of occurrence of the assumed _ accident or malfunction. The RCS flow rate is an assumption in applicable safety analyses. Existing analyses of record have assumed RCS flow rates which are bounding with respect to expected actual plant behavior. Therefore, the implementation of the proposed Technical Specifications change does not affecn the probability nor increase the consequences of an ace:ident previously evaluated.

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2. Create the possibility of a new or different accident from any accident previously identified.

The proposed change to North Anna Units 1 and 2 to Table 3.2-1, DNB Parameters, of Technical Specifications 3.2.5 does not involve any changes which would introduce any new or unique operational modes or accident precursors. Only the allowable value for measured Reactor Coolant System Total Flow Rate will ,

be changed.

3. Involve a significant reduction in a margin of safety.

I The. margin of safety as defined in the basis of the technical specifications is not reduced. The proposed Technical Specifications change only increases the minimum allowable RCS total flow rate in the applicable Limiting Condition of Operation. The RCS flow rate is an assumption in applicable safety analyses. Existing analyses of record have assumed RCS flow rates which are bounding with respect to expected actual plant behavior. Therefore, the margin of safety is not reduced by the proposed increase in the allowable RCS Total Flow Rate.

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Virginia Electric and Power Company concludes that the activities associated with these proposed Technical Specifications changes do not pose a significant hazards consideration as described in 10 CFR 50.92 and, accordingly, a no significant hazards consideration #

finding is justified.

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