Advancing Neutron Safety and Dosimetry in Nuclear Facilities: Applications and Current Status of the Development of Nereida

The development of nuclear facilities necessitates reliable tools for design, licensing, and safety assessments. NEREIDA (the Spanish acronym for fast neutrons for the exploitation of facilities with atomic devices) is being developed for providing a robust solution. Utilizing Geant4-based Monte Carlo methods, NEREIDA characterizes neutron flux spectra and calculates dosimetric quantities such as environmental and personal dose equivalents in any neutron-production facility. This innovative tool integrates state-of-the-art codes for neutron transport, interaction, moderation, and material activation. Our preliminary results, obtained after the first year of a three-year development period, demonstrate computational scalability across various high-performance computing clusters and clouds. NEREIDA will generate the Geant4 facility's models from CAD files, structural materials, and neutron source characteristics without requiring programming expertise. Additionally, NEREIDA models the impact of the cosmic ray background and includes anthropomorphic phantoms for comprehensive safety assessments. This work discusses NEREIDA's current status and future directions, emphasizing its critical role in enhancing nuclear facility safety.