The Monte Carlo method is commonly applied in fusion neutronics to simulate particle transport calculations due to its ability to handle complex geometries and perform accurate calculations with continuous-energy cross-section data. FLUKA, a versatile particle transport calculator specializing in radiation shielding analysis, features an interactive modeling interface, Flair. FLUKA seems capable of calculating key fusion neutronics parameters, such as neutron energy spectra, material activity, and the shutdown dose rate (SDDR) in a single step, indicating its potential for fusion neutronics analysis.

This study uses the ITER SDDR experiment T-426 as a benchmark case. Besides the calculation results for the neutron flux and material activation between FLUKA and other commonly used tools that showed significant discrepancies, the calculated-to-experiment (C/E) values for the SDDR calculated by FLUKA after 7 days of shutdown ranged from 1.03 to 1.35, while the C/E values from other methods typically fall between 0.8 and 1.2. Although FLUKA is able to calculate various parameters of interest to fusion neutronics, it still requires further validation and development to better simulate neutron transport for fusion application.