Augmentation of the neutronic safety aspect of high-density fuel research reactor using new control element design

Abstract The development of a 10 MW research reactor core using high-density U 3 Si 2 –Al plate fuel is presented, focusing on enhancing neutronic safety through optimized core configuration and control element design. This study employs MCNP and CITATION codes to evaluate neutronic parameters, including Power Peaking Factor (PPF) and Stuck Rod Shutdown Margin (SRSM). By incorporating four symmetrical irradiation boxes in the core center, the PPF is reduced by approximately 5 %, distributing neutron flux more uniformly. A novel control assembly design with a thin D 2 O layer increases control rod worth ensuring SRSM <−1,000 pcm without additional absorber material. Reactivity feedback analysis confirms safe operation with negative coefficients for fuel temperature and moderator conditions (−1.56 pcm/°C for D 2 O −20.11 pcm/°C for combined moderator temperature and density with D 2 O). This approach enhances safety margins and extends cycle length, offering a novel solution for high-density fuel research reactors.