ML17037C340

Letter Responding to the February 28, 1972 Letter Proposing Changes to the Technical Specifications and Requesting Additional Information to Continue the Review and Evaluation of the Changes and Analyses

ML17037C340
Person / Time
Site:	Nine Mile Point
Issue date:	03/21/1972
From:	Skovholt D US Atomic Energy Commission (AEC)
To:	Brosnan T Niagara Mohawk Power Corp
References
Download: ML17037C340 (4)

Text

MAR 2 I >gag Docket No. 50-220 Niagara Mohawk Power Corpo'ration ATTN: Mr. Thomas J. Brosnan Vice President and Chief Engineer 300 Erie Boulevard Hest Syracuse, New York 13202 Gentlemen:

Your letter dated February 28, 1972, proposed changes to the Technical Specifications of Provisional Operating License No. DPR-17 for the Nine lQ.le Point (KP) Nucleax Station. The proposed changes include lowering the set Points of the solenoid-actuated pressure rolief valves, lowering the set point for initiation of the emergency cooling condensexs and incxeasing the requirement for operation of five, rather than'four, relief valves to maintain the sama margin between t: he transient peak pressure and the safety valve set points. ,These proposed changes to the Technical Specifications are xequixed as the result of xevision of the basic scram reactivity curves used to calculate KP systems t response to transients. To continue our review and evaluation of the proposed changes and the accompanying analyses, the following additional infor-mation is required:

l. You state that improved analytical techniques available at General Electric Company caused you'to adopt the proposed revised scram reactivity curve, but no information regarding

'these techniques was provided. Describe the analytical techniques used previously, the changes being made to the analytical model, and the basis for considering the cnange an improvement.

2~ Describe the data and measurements obtained at K%'rom reactor operations and tests that support use of the new analytical techniques.

3~ The effect of partial xefuelings on the scram reactivity Jh curve has no't been presented. Please define the xelation-ship of the present core loading with the scram reactivity

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curve and describe the effect on scram reactivity from approaching an equilibrium fuel loading, including the expected operational control rod patterns.

4. Your analyses supporting the proposed changes do not include consideration of the control rod drop accident. Th'..change in slope of the scram reactivity curve would indicate an increased rate of reactivity insertion in the event of a control xod drop accident. Provide a complete reanalysis of this accident, including consideration of the validity of the assumed maximum reactivity worth of the control rod involved in the, drop accident. Your attention is directed to a letter dated Harch 8, 1972, to Hr. A. P. Bray of the General Electric Company from R. S. Boyd, Division of Reactor Licensing. A copy of this letter is enclosed for your convenience.

You are requested to provide information responsive to the above concerns by Hay 1, 1972. Please provide one signed and 39 additional copies of the infoxmation. Do not hesitate to contact Hessrs. C. J. DeBevec or D. L. Ziemann of my staff for clarification of the requested information.

Sincerely, Donald J. Skovholt Assistant Director for Reactor Operations Division of Reactor Licensing

Enclosure:

Distribution Ltr fm Boyd to Bray PDR dtd 3/8/72 acket Pile DRL Reading cc w/enclosure: Branch Reading Axvin E. Upton, Esquire ACRS (16)

LeBoeuf, Lamb, Leiby 6 HacRae OGC (2) 1821 Jefferson Place, N. W. Compliance (2)

Washington, D. C. 20036 PSchroeder,DRL DJSkoVhOl, DRL DLZiemann, DRL DRL RHDiggs,

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moux NY Co OFFICE > DRL DR DRL ~ DRL SURNAME 5 JDeBevec:sg RH 's JA DLZiemang P

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DATE D 3/20/72 3/20/72 3/2d/72 .3,/. l72.

Fotm hEC-318 (Rcv. 9-53) hKCM ONO 'AV, S.GOVERNMENT PRINTINO OFFICE: 1071 MI0~00

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