Multiphysics Modeling of Heat Pipe Microreactor with Critical Control Drum Position Search

Abstract

A multiphysics coupling methodology for heat pipe microreactors is presented in this work that includes a focus on a critical control drum position search routine and burnup capabilities. As the Serpent code is used for neutronics calculations, the recently developed GRsecant method for finding critical control drum positions is employed, which has explicit measures to manage the uncertainty introduced from the Monte Carlo calculation method. This work complements existing multiphysics modeling tools for heat pipe microreactors because it can be used to generate cross sections with fuel compositions determined by depletion with critical control drum positions. These methods are applied to a microreactor design motivated by the eVinciTM heat pipe microreactor. The convergence of the multiphysics coupling routine is analyzed at multiple burnup points. The multiphysics iterations with critical control drum search were observed to converge for all calculations performed in this work. Overall, the multiphysics coupling procedure enables the calculation of both thermal and neutronics characteristics with control drums in their critical positions for the core lifetime.