ML20095C758
| ML20095C758 | |
| Person / Time | |
|---|---|
| Site: | Mcguire, Catawba, McGuire  |
| Issue date: | 12/04/1995 |
| From: | Tuckman M DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9512120201 | |
| Download: ML20095C758 (3) | |
Text
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l-Duke Pbwer Cornpany.
MSTlaw P.O. Box 1006 Senior VicePresident Owlone, NC?}.?01-1006 NuclearGeneration (704)3822200 Omce (704)3824360 Fax DUKEPOWER December 4,1995 U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Attention: Document ControlDesk
Subject:
McGuire Nuclear Station Docket Numbers 50-369 and -370 Catawba Nuclear Station Docket Numbers 50-413 and -414 Duke Use of the BWU-Z Critical Heat Flux Correlation
References:
- 1. Letter from M.S. Tuckman to Document Control Desk, Duke Use of the BWU-Z Critical Heat Flux Correlation, October 13,1995, L 2. BAW-10199, The BWU Critical Heat Flux Correlations, BWFC, submitted November
- 1994,
- 3. DPC-NE-2004P-A, Duke Power Company McGuire and Catawba Nuclear Stations Core Thermal-Hydraulic Methodology Using VIPRE-01, December 1991.
- 4. DPC-NE-2005P-A, Duke Power Company Thermal-Hydraulic Statistical Core Design Methodology, February 1995.
- 5. NRC letter from Herbert N. Berkow to M.S. Tuckman, Duke Power Company's Use Of TACO-3 And The Fuel Rod Gas Pressure Criterion For The Oconee, McGuire, and Catawba Nuclear Stations, April 3,1995.
- 6. NRC letter from Herbert N. Berkow to M.S. Tuckman, Duke Power Company Use Of CROV Computer Code, June 19,1995.
Duke notified the NRC (Reference 1) ofintent to use the BWU-Z cdtical heat flux (CHF) correlation for licensing and analyses of the Catawba 2 Cycle 9 core. This approach is tied to the NRC review and approval of the BWU correlation (Reference 2). This approach also involves a licensing process discussed in several meetings with the NRC. In a 12 anno j i Pa2 1 Bad Pa!8*,
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i U. S. Nuclear Regulatory Commission December 4,1995 4
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1 telephone conversation on November 20,1995, the NRC requested clarification on some j-of the issues relating to the application of Reference 2 at Duke.
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~ Reference 1 cited the BWU-Z correlation in particular as the correlation required for the l
Catawba 2 Cycle 9 analyses. The BWU-Z designation is in reference to the correlation in -
the BWU form with specific coef5cients applicable only to the Mark-BW 17x17 fuel type.
i Reference 2 contains documentation to verify the acceptability of a universal local conditions CHF correlation form as well as specific information for three different fuel designs to which this form is applicable (Reference 2, Page 1-3). As noted on pages 4-3 L
' and 4-4 of Reference 2, the BWU-Z correlation is applicable only to the Mark-BW 17x17 i
design. Two other applications of the universal correlation are described in Reference 2
[
and denoted as BWU-I and BWU-N. These two forms apply to different fuel designs, and 4
have different coefficients and applicable data ranges. Duke intents to use only the BWU-i=
Z with the same coefficients and within the BWU-Z range of applicability listed in Table 4-1, page 4-5, of Reference 2.
l The BWU-Z form of the BWU correlation used by Duke in analyses for McGuire and l
Catawba is exactly the same as the correlation represented in Reference 2. The BWU-Z j
correlation is transferred to the VIPRE-01 computer code and confirmed to be applicable i.
according to the method described for the BWCMV correlation in Reference 3.
Following confirmation, the statistical design limit for the BWU-Z form of the BWU 2
correlation for Mark-BW 17x17 fuel at McGuire and Catawba is calculated as described in Reference 4. These two steps have been completed.
j Duke is pursuing the application of the BWU-Z form of the BWU correlation to Catawba 2 Cycle 9 as a Cost Beneficial Licensing Action. The BWU-Z correlation conservatively j
accounts for the enhanced thermal performance of the Mark-BW fuel assembly design compared to previous 17X17 mixing vane fuel designs. The better thermal performance of the fuel can be translated into changes in core loading schemes that will save $500,000 per fuel cycle. This cost savings can only be realized when the approval for the analyses methods detailed in the Reference 1 letter is received.
As stated in Reference 1, the BWU-Z form of the BWU correlation will be applied with approved Duke methods (Reference 4). No modification to existing NRC-approved methods nor use of non-NRC approved methods is proposed. NRC approval of Duke's use of BWU-Z by the process outlined in Reference 1 is consistent with methods discussed in an August 15,1995 meeting between the NRC and Duke, and processes previously used by NRC to approve Duke meth)ds without formal topical report submittal (References 6 and 7).
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1 U. S. Nuclear Regulatory Ccmmission December 4,1995 Page 3. ',
j If any additional assistance is required relating to the issue of using the BWU-Z -
correlation or the licensing approach proposed for approval at Duke, please feel free to contact Mr. Ronald Gribble at (704) 382-6160.
Very truly yours, O
M. S. Tuckman j
i a
cc:
Mr. R. E. Martin, Project Manager j
Oflice ofNuclear Reactor Regulation j
U. S.NuclearRegulatory Commission Mail Stop 14H25, OWFN Washington, D. C. 20555 Mr. V. Nerses, Project Manager Office ofNuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop 14H25, OWFN Washington,D.C. 20555 Mr. S. D. Ebneter, Regional Administrator -
U.S. Nuclear Regulatory Commission - Region II 101 Marietta Street,NW-Suite 2900 Atlanta, Georgia 30323 Mr. G. F. Maxwe!!
SeniorResident Inspector McGuireNuclear Station Mr. R. J. Freudenberger Senior Resident Inspector Catawba Nuclear Station i
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