ML19270F205
| ML19270F205 | |
| Person / Time | |
|---|---|
| Issue date: | 01/26/1979 |
| From: | Dunenfield M Office of Nuclear Reactor Regulation |
| To: | Kniel K Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7902050021 | |
| Download: ML19270F205 (2) | |
Text
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NUCLEAR REGULATORY COMMISSION
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JAN 2 61979 MEMORANDUM FOR:
K. Kniel, Chief, Core Perfonnance Branch, DSS w
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D. Fieno, ider, Reactor Physics Section, CPD, DSS at)c-FROM:
M. Dunenfeld, Reactor Physics Section, CPB, DSS
SUBJECT:
DSS-BNL MEETING 1/5/79 A meeting was held at BNL on January 5, 1979 between D. Diamond, the BNL Technical Assistance staff, and M. Dunenfeld. The primary purpose of the meeting was to discuss alternatives and reach a decision on how to do the EOL constant axial offset control (CAOC) studies we have scheduled this fiscal year (FIN A3128). The problem is getting EOL cross sections for use in DWARF.
DWARF is a 1-L diffusion theory code into which we programmed controls on axial flux difference, baron concentration, control rod position, etc., in order to be able to do the CAOC studies automatically. The most economic way to calculate spatial core burnup is to use a nadal code (EPRI NODE), but this doesn't give cross sections for DWARF.
One option was to reprogram the controls we put into DWARF into EPRI-N0DE. This would have the additional arivantage of facili-tating any future non-BOL CAOC studies we may undertake.
I indicated that we didn't have any such studies planned, but also objected to this alternative because we would have to spend considerable time and money on something we've already done.
Furthermore, it is fairly certain we will replace EPRI-N0DE with SIMULATE, and programming something three times is out.
A second option is to run the spatial depletion in PDQ-7, which yields cross sections.
BNL is hesitant to do this because a 3-D PDQ-7 run is expensive (thousands of dollars).
I agree, but if we had a fat budget, this is the way to go, and we should eventually be prepared to do it when less expensive alternatives are questionably acceptable.
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k JAN 2 t,1979 MEETING
SUMMARY
The last option, which we chose, is to use the spatial exposure distribution calculated by EPRI-N0DE to get the cross sections from exposure (but not spatially) dependent cross sections we have from EPRI-Celi./PDQ analyses. We can check the accuracy of this by comparing transient DWARF calculations using these
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cross sections with data.
Another subject discussed was progress with MEKIN, the three dimensional kinetics code. BNL has been getting unstable results in the thermal-hydraulic feedback for a BWR model.
BNL has received a set of corrections for the thermal-hydraulic model from MIT.
It is hoped these might solve the problem. The changes are being made, and will be evaluated shortly.
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6 Marvin Dunenfeld Reactor Physics Section Core Performance Branch Division of Systems Safety cc:
R. Mattson/F. Schroeder R. Fraley, ACRS (16)
ISE (3)
OR, SS&EA, PM & SS ads SD & RES ads S. Weiss M. Dunenfeld
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e MEETING SDNARY DISTRIBUTION JAN 171979 Docket File NRC PDR Local PDR TIC NRR Reading thR #4 File E. Case R. Boyd D. Vassallo W. Gammill J. Stol:
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