Nuclear design study for innovative natural circulation molten salt fast reactor

Abstract

To achieve a long-life core, prevent severe accidents, and implement a passive safety system through a natural circulation approach in a fast spectrum Molten Salt Reactor, the concept of a Passively-Cooled Molten Salt Fast Reactor (PMFR) has been proposed and thoroughly examined. This innovative concept involves assessing novel installations of moderators, burnable absorbers, and control drums to attain an optimal reactor design configuration. The resulting configuration underwent detailed neutronic analysis aimed at minimizing reactivity swings while ensuring the long-life operation and safety system. The neutronic analysis consists of evaluation of depletion result, neutron flux distribution, power distribution, temperature coefficient, control drum worth, shut down margin, fission product build-up, neutron fluence, and evaluation of kinetic parameters. This investigation utilized the Monte Carlo Serpent2 code version 2.1.31, employing the ENDF/B-VII.1 nuclear library. The final design attains a prolonged reactor lifespan of 35.9 years, surpassing the non-moderated initial design by 18.57 years. This is achieved through the utilization of a control drum worth that ranges between 2,125 pcm to 11,032 pcm from BOL to EOL conditions.