Neutronic analysis on different configuration of ARC-like tokamaks

The research field for fusion energy is developing rapidly and in addition to the well known mega project (e.g. ITER, DEMO), compact fusion tokamaks are under investigation. One interesting compact reactor is ARC (Affordable, Robust, Compact), a fusion device under development by Commonwealth Fusion Systems, designed for efficient energy production and material testing, which also involves research activities in Italian universities and industry. The presented work is developed in this framework and focuses on a neutronic analysis of an ARC-class fusion reactor. Monte Carlo simulations are carried out by means of OpenMC tool, to estimate Tritium Breeding Ratio (TBR), power generation, and neutron spectrum. First, a CAD-based model of an ARC-class reactor is built, incorporating key components such as the vacuum vessel, the breeding blanket, and the cooling systems. Simulations explore neutron behavior across these components, analyzing how variations in first-wall thickness impacts neutron transport and the efficiency fo the whole system. The study concludes with an uncertainty propagation analysis in which the cross sections of the isotopes are modified to assess the impact on the simulation results of their uncertainties. This evaluation aims to optimize design parameters contributing to the ARC reactor's role as both an energy source and a testing facility for advanced materials.