Serpent and TRIPOLI-4® transient calculations comparisons for several reactivity insertion scenarios in a 3D PWR minicore benchmark

In recent years, there has been a growing interest in developing high-fidelity reactor physics calculations, for both stationary and transient (operational and accidental) behavior. In this context, the H2020 McSAFE project represents a collaborative effort led by 12 institutions from 7 EU countries to provide reliable and efficient numerical tools for the simulation of generation 2 and 3 light water reactors (LWR). In order to meet this challenge, several new major features are under development for Monte Carlo codes to be able to simulate non-stationary neutron transport with and without thermal-hydraulic feedbacks. Within this framework, in the present work a series of transient scenarios with reactivity insertions due to control rod movement for a 3D PWR Minicore benchmark are proposed and analyzed. Simulations are obtained based on the Serpent and TRIPOLI-4 ^® Monte Carlo codes, where kinetic capabilities have been recently (and independently) developed. The respective results are compared to each other in order to assess the accuracy of non-stationary simulations on realistic configurations. Running times, convergence and foreseen requirements are also briefly discussed.