2023

Tuominen, Riku; Valtavirta, Ville

In this work the nodal neutronics code Ants is coupled with the subchannel code SUBCHANFLOW and the fuel behavior code SuperFINIX within VTT’s Kraken framework in order to evaluate thermal margins. The coupling is implemented using Cerberus which is the multi-physics driver of Kraken. The capabilities of the new coupled code system are demonstrated by modeling the first operating cycle of BEAVRS. Calculated and measured boron concentrations are compared and selected pin-by-pin results are presented at 3 points during the operating cycle. In addition, the modularity of the Kraken framework is highlighted by modeling the depletion of a 3D single fuel assembly with both Ants and Serpent based code systems. This capability can be used to assess the accuracy of nodal neutronics vs continuous energy Monte Carlo in the estimation of thermal margins. Finally, some possible topics for future work are introduced.