NEUTRONIC MODELING OF A FAST CORE WITH MODERATING MATERIALS USING APOLLO3R CODE

In order to improve passive safety of Sodium-cooled Fast Reactors The French Alternative Energies and Atomic Energy Commission (CEA) has proposed a new core design called CADOR - an SFR with enhanced Doppler reactivity feedback. One its most important features is the introduction solid moderating materials inside each fuel assemblies slightly decrease average neutron energy. article focuses on development validation neutronics calculation scheme able produce accurate results in case other fast cores materials. study uses two different assembly models moderated by metallic beryllium zirconium hydride (ZrH 2 ) respectively includes discussion scattering treatment ways spatial homogenization energy condensations. indicate that leads much better estimation constant, especially ZrH core. By using combined deterministic-Monte Carlo we are quantify biases global reactivity, feedbacks control rod worth. We demonstrate plays more role thus preserving certain level heterogeneity within can lower bias significantly.