ML20216J217

Informs That Encl Questions Were Transmitted by Email on 990930 to M Purser of Duke Energy Corp for Preparation of Upcoming Telcon.Questions Pertain to 990624 Amend Request

ML20216J217
Person / Time
Site:	Mcguire, Catawba, McGuire
Issue date:	09/30/1999
From:	Tam P NRC (Affiliation Not Assigned)
To:	NRC
References
TAC-MA5989, TAC-MA5990, TAC-MA5994, TAC-MA5999, NUDOCS 9910040233
Download: ML20216J217 (3)

Text

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{p 2% UNITED STATES s* j NUCLEAR REGULATORY COMMISSION WASHINGTON. D.C. 20665-0001

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MEMORANDUM FOR: Docket File FROM: Peter S. Tam, Senior Project Manager, Secti n 1 Project Directorate il <-

).y Division of Licensing Project Management ' -

Office of Nuclear Reactor Regulation

SUBJECT:

CATAWBA AND MCGUIRE NUCLEAR STATION - l ELECTRONIC TRANSMISSION, ISSUES TO BE DISCUSSED IN AN UPCOMING TELEPHONE CONFERENCE REGARDING j AMENDMENT REQUEST DATED 6/24/09 {

(TAC MA5989, MA5990, MA5994 AND MA5909)  !

The attached questions were transmitted by email today to Ms. Martha Purser of Duke Energy Corporation (DEC) to prepare her and others for an upcoming telephone conference. This memorandum and the attachment do not convey a formal request for information or represent an NRC staff position.

Docket Numbers 50-413 and 50-414 50-369 and 50-370 Distribution PUBLIC ,

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9910040233 990930 PDR ADOCK 05000369 P PDR

s REQUEST FOR ADDITIONAL INFORMATION REGARDING MCGUIRE/ CATAWBA NUCLEAR POWER STATIONS PROPOSED TECHNICAL SPECIFICATION AMENDMENTS TAC NOS. MA5994, MA5995, MA5989, AND MA

1. You stated (in item L, page 13, attachment 3 to the June 24,1999, letter) that the analysis of the uncontrolled reactor core control assembly (RCCA) bank withdrawal at power event was performed in accordance with the analytical model and methodology described in Topical Report DPC-NE-3000 and DPC-NE-3002; and that "since the minimum DNBR calculated with a standard axial power shape is found to fall below the 1.50 design limit, MARP [ maximum allowable radial peak] curves are generated in order to determine the number of fuel rods, if any, that experience departure-from-nucleate boiling (DNB). The revised MARP curves allow greater radial peaking for all axial peaks and locations. Therefore, the conclusion that no fuel failures occur remains valid for the revised analysis." This approach and conclusion appear to use the comparison of the MARP curves as a substitute to safety analysis and disregard the safety analysis result with the minimum DNBR below the design limit, Please clarify and/orjustify.

Specifically:

(A) Provide the references where this approach was described and accepted by the staff.

(B) Provide technical basis for the acceptability of this approach (see question 6).

(C) Clarify the statement that "the revised MARP curves allow greater ra

. .." If the revised MARP curves allow greater radial peaking than the current MARP curves, does that mean the current safety analysis also showed the minimum DNBR below the design limit as does the revised safety analysis? If not, what led to the inconsistency (see question 4)?

(D) Explain how the hot fuel rod with a minimum DNBR below the design limit of 1.50 will not experience DNB7

2. Section 5.2.2.2 of DPC-NE-3002-A stated that the uncontrolled RCCA bank withdrawal at power event is analyzed with a spectrum of initial power levels which range from low power to full power.. Provide your re-analysis results for each power level (from low to full power) analyzed for the event. The information provided for each case should include the following parameters:

Initial cor:ditt ;~;imt scwar level, axial peaking factor and location, radial peaking factor, RCS flow rate, pressure, inlet flow temperature Control system reactivity insertion rates (minimum and maximum)

Fuel and moderator feedback reactivity coefficients (minimum and Maximum). l

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l Results of analysis including reactor trip function and trip time, and the following parameters as a function of time during the transients: nuclear power, heat flux, pressurizer pressure, core average temperature, and minimum DNBR.

3. Are the radial peaking factors used in this safety analyses for various e s for the uncontrolled RCCA withdrawal event consistent with the values specified in technical specification LCO 3.2.2 as defined in the Core Operating Limits Report (COLR) Section 2.67

4. Describe the differences between this safety analysis (the uncontrolled RCCA withdrawal l at power related to the proposed TS change) and the safety analysis of the same event described in Section 15.4.2 of Updated Final Safety Analysis Report. The description should include the differences, with explanation, in inputs, methods used, and results of  ;

analyses.

5. Provide the " revised MARP curves" generated for your re-analysis of the uncontrolled l RCCA bank withdrawal at power. Also:

MARP Describe curves theindifference provided between Table 7, Appendix these A of the COLR.revisedt MARP cupJ Define the MARP curves. Are the revised MARP curves the loci of the radial peak factors as a function of axial peak and location that result in the minimum j DNBR during the transient at the design limit? l Are the revised MARP curves dependent on the initial power level? Is the power dependency consistent with LCO 3.2.2 on the radial peaking factor?

If the revised MARP curves allow greater radial peaking, why does the revised safety analysis of the event result in the minimum DNBR below the design limit?

Do the revised MARP curves bound the radial peaking factors with initial power level correction used in the safety analysis?

6. Describe how the " revised MARP curves" and the COLR MARP curves are generated.

(Catawba TS BASES B.3.2.2 states that the MARP limits are developed in accordance with the methodology outlined in DPC-NE-2005P, which, however, does not provides the MARP development methodology.) In addition to referencing another topical report which describes the MARP limit methodology, if any, please provide a step-by-step description (from initial conditions, analyses of plant responses of transients, and calculations of minimum DNBR during the transients) of how both "COLR" and " revised" MARP curves are generated. The description should be detailed enough to provide an explanation and understanding on how they can be used to substitute for the safety analyses, especially when the resulting minimum DNBR below the design limit (see question 1).

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