Addressing the accuracy quantification issue for CFD simulation of in-vessel flows

The presentation was devoted to accuracy quantification in the CFD investigation of in vessel flows. An example of the multi-dimensional information that needs to be captured is represented by the time and space distribution of coolant properties (e.g. temperature, boron concentration) at the reactor core inlet, a topic relevant to reactor safety as local perturbations, because of the potential to induce power excursions. An attempt was made to tackle the accuracy quantification issue for this class of data in a somewhat empirical way by proposing a set of parameters that can be used, after a qualitative analysis of measured data and code simulation results, to characterise the “perturbation” of tvessel flowhe target variable time and space distributions, and to quantify the deviation of the simulation from the experimental data. The advantage of using many parameters relies on the ability to cover all relevant features of the chosen target variables, and thus provide a more complete assessment and regarding overall agreement.