ML17319B496
| ML17319B496 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 08/02/1982 |
| From: | Berlinger C Office of Nuclear Reactor Regulation |
| To: | Varga S Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML17319B494 | List: |
| References | |
| NUDOCS 8209020114 | |
| Download: ML17319B496 (2) | |
Text
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~y UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, O. C. 20/55 AUG 5 588 MEMORANDUM FOR:
Steven A. Varga, Chief Operating Reactors Branch b'1 Division of Licensing FROth:
SUBJECT:
Carl H. Berlinger, Chief Core Performance BIranch Division of Systems Integration D.
C, COOK UNIT 2 CYCLE 4 RELOAD Presently the Core Performance Branch (CPB) is reviewing XN-NF-82-21, "Application of Exxon Nuclear Company PWR Thermal Margin Methodology to Mixed Core Configurations,"
and XN-NF-621, Revision 1, "Exxon Nuclear DNB Correlation for PWR Fuel Designs".
Both of these topical reports are referenced by the Indiana and Michigan 'Electric Company as supporting information for the Cycle 4
operation of D.
C.
Cook Unit 2.
CPB has reviewed the methodology described in XN-NF-82-21(P) and identified a
number of concerns on ENC's approach to calculating the location and value of the minimum departure from nucleate boiling ratio (MDNBR).
We anticipate completing our review of this topical by September 30, 1982.
This would be consistent with the Cook 2 startup date of December 1, 1982; however, the conclusion presently being formulated by CPB is that the use of this methodology may result in a DNBR penalty.
With respect to the critical heat flux {CHF) correlation presented in XN-NF-621, Revision 1,
CPB has contracted with the Idaho National Engineering Laboratory
( INEL) to review the validity of the correlation.
INEL has a
number of concerns with the correlation and CPB does not foresee completing our review in time for the Cook reload.
Therefore, we are recommending that the licensee submit revised safety analyses using the W-3 CHF correlation.
In addition to these
- concerns, CPB has a major concern in the area of thermal-hydraulic compatibility of two different types of fuel assemblies, e;g., fuel rod ODs of 0.374" and 0.360" and different grid designs.
Before we can approve a mixed core reload of this type, Exxon must provide additional submittals which demonstrate in a more quantified manner the effects on diversion cross-aa090aOSSO 8208>9 PDR ADOCK 05000316 P,
.. PDR
Steven A. Varga 2
AUG 2 1982 flow of the different grid designs and fuel pin diameters and the consequential effects on DNB.
- Also, ENC should provide information which demonstrates that sufficient thermal margin is available to account for any interbundle crossflow uncertainties.
In recent discussions with the project manager, we were informed that the August 1, 1982 due date could be altered; therefore, CPB is requesting that the August 1, 1982 due date be postponed to November 23, 1982.
Also the above information should be submitted by Exxon at 'least two months prior to November 1992.
This will ensure that sufficient time is av~aialbe for CPB to perform a complete review of the submittal.
cc:
R. Hattson L. Rubenstein J.
Berggren R. Cilimberg Carl H. Berling r, Chief Core Performance Branch Division of Systems Integration