A Proposal of a Hybrid Fusion-Fission System Based on Arc

Abstract

Studies are being carried out looking for technologies for a compact, robust and affordable reactor that aims to reduce the size, cost, and complexity of a fusion reactor installation. One promising fusion reactor underway at the Massachusetts Institute of Technology (MIT) is the Affordable Robust Compact Reactor (ARC). This reactor uses high-temperature superconductors (HTS), which allow the generation of large magnetic fields on the shaft and therefore reduce its size. The fusion reactor ARC operates using the same deuterium-tritium (DT) fusion reaction of the International Thermonuclear Experimental Reactor (ITER) reactor, whose neutron energy produces about 14.1 MeV, these neutrons enhance the fission probability in Minor Actinides. The Department of Nuclear Engineering (DEN/UFMG) has been working on studies of hybrid systems based on fusion-fission systems based on ITER with the insertion of a transmutation layer. Therefore, the transmutation layer works in a subcritical state, and it is loaded with reprocessed nuclear fuel including Minor Actinides (MAs), which could increase their probability of inducing transmutation by fission with high-energy neutrons. Therefore, this work aims to investigate the neutron flux variations over the ARC reactor's different components. For this study, three systems have been studied ARC1, ARC2, and ARC3. They were simulated using the Monte Carlo N-Particle Transport eXtended method (MCNPX), the ARC1 represents the original compact reactor model, ARC2 is a single homogenized transmutation layer, and ARC3 considers two fuel layers. The results analyzed the best position for the insertion of a transmutation layer inside ARC1. On the other hand, the models ARC2 and ARC3 made it feasible to understand the variations of the neutron flux after the insertion of the transmutation layer under two different simulations.