ML20102B200
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i December 12, 1983 Note to Dan Mcdonald
SUBJECT:
TURKEY POINT F aH Q
This package presumes and is keyed to the concept that the change.in modeling can be justified under the example that says a change resulting from the appli-cation of a small refinement of a previously-used calculational model or design method. Somebody has to come to grips with whether in fact these are small refinements of a previously used calculational model or design method.
I don't have sufficient information in any of the materials I've seen yet to reach that conclusion and I can't tell whether the change in the ECCS modeling results in significant, dramatic changes or not. For example, I know that there are a number of things in the Turkey point package that we changed. We changed the limitations because of the plugging in the tubes and we also changed character-istics based on the use of the WABA rods and these are now calculated by BART modeling techniques and seems to be okay; however, I can't tell how much of the changes are due to the BART modeling techniques and how much of the changes are due to other phenonmena. We apparently do not have a calculation using t'.e traditional ECCS evaluation model of Westinghouse The old model is still acceptable), which evaluating maximum peak clad temperature and maximum core characteristics under the old model to which we compare the results using
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the new mooel. Some place along the line, this proceeding will need this in order to justify the story that says the modeling changes are small. For all I know, the major element in allowing the plant to operate at full power without significant power limitations are changes in the ECCS modeling.
If that's true then I think you'll have a very difficult time just to find the conclusion that there are small refinements in the calculational model.
In the ECCS modeling packages, I see no comparison of results of the ECCS calculational system using the BART component and the ECCS calculational system under the traditional model.
I just don't know what the differences are and I can't tell from what we have that the changes are in fact small. They may be substantial.
If you had suffi-cient information to reach the conclusion that the modeling changes are not significant, that would help a lot. 'In the absence of that information, I don't know how you reach conclusions like changed margins aren'.t significant.
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_ If the old model had indicated that you can't operate it in conformance with.
50.46 at power levels above 90% and the new model allows you to operate at a power level of 100% with a peak clad temperature of slightly below 2200, then somebody will have to discuss at some length, the basis for the conclusions that the margins haven't significantly changed.
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