A preliminary simulation study of dynamic rod worth for the SMART (System-integrated Modular Advanced ReacTor) reactor

Abstract

This paper describes a preliminary simulation of the dynamic rod worth for the SMART (System-integrated Modular Advanced ReacTor) reactor core which has been developed by KAERI (Korea Atomic Energy Research Institute). This work was done by comparing the dynamic rod worth calculated using a simple inverse kinetic model with simulated pseudo ex-core detector signals and the static rod worth calculated with 3D static core diffusion nodal calculations. The kinetic parameters for the simple inverse kinetic model are estimated by using 3D static core diffusion nodal calculations as functions of the rod positions while the pseudo ex-core detector signals as the control rod positions change are simulated by using 3D transient core diffusion calculations with the MASTER (Multi-purpose Analyzer for Static and Transient Effects of Reactors) code and the ex-core detector response function calculated with the DORT code. Then, the pseudo ex-core detector signals are converted into the core neutron flux using the pre-estimated ex-core detector response conversion factor (DRCF). The simulation results show that the dynamic rod worth with the simulated pseudo ex-core detector signals have good agreement with the static rod worth for the SMART reactor and that the deviations of the static and dynamic rod worth from uncertainties of control rod group constants show good agreements with each other. So, it is considered that this work can provide baseline data for the actual simulation using real ex-core detector signals for the SMART reactor in the future.