Neutronic analysis of the fusion reactor ARC: Monte Carlo simulations with the Serpent code

The fusion reactor ARC proposed by MIT is a concept of high-magnetic field reactor, using high temperature superconductors (HTS), with an innovative liquid breeding blanket (BB) made of a molten salt (FLiBe). The plasma chamber and the vacuum vessel are contained in the liquid breeding blanket and the FLiBe is used also for the cooling of the vacuum vessel and of the divertor. The lithium (isotopically enriched with 90% 6Li) contained in the molten salt has the aim of producing tritium after the interaction with the neutrons produced by the fusion interactions. FLiBe is then extracted from the breeding blanket and sent in a heat exchanger to produce electricity thanks to the power deposited in the BB by the neutrons and the photons. The designed fusion power of ARC is 525 MW and its total electric power 283 MW. The presence of high-magnetic field allows to reduce the dimensions of the reactor, with possible benefits on the capital cost. The aim of this work is to analyze the neutronics of ARC through Monte Carlo simulations using the Serpent transport code. In particular, the simulations are focused on the estimation of the Tritium Breeding Ratio and of the distribution of the generated power by neutrons and photons in the blanket tank, while the aspects concerning the neutron shielding are not taken into account.