Burnup Adaptation Model in STREAM/RASTK Code System

It is impossible to quantify the effects and have them considered in the calculations. This will result in the departure of the prediction data from the actual (operation) data and will cause error/bias for the following modeling and operation of the plant. The idea of BUA is that the computed power distribution is sensitive to the spatial distribution of assembly reactivity errors, which is sensitive to the distribution of the assembly burnups. In addition, the change of the plant operating condition will cause a change in the power distribution, which will then cause a change in the burnup distribution. Therefore, by adjusting the assembly burnups, it is possible to produce a better agreement between the calculated and reference power distributions, which is a compensation of the unknown operation condition change in the modeling. The numerical results of a typical OPR1000 core successfully demonstrate the capability of this burnup adaptation technique. Further investigation will be conducted on the optimization problem, like the simultaneous optimization of the factors for all the sub-batches instead of the current sequential process, and the possible automatic sub-batch grouping using machine learning instead of the current manual grouping.