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arXiv · 2507.04129

High-Fidelity Modelling of the Molten Salt Fast Reactor

Maximiliano Dalinger·Elia Merzari·Saya Lee·Casey Emler
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Abstract

The Molten Salt Fast Reactor (MSFR) is one of the six GEN-IV reactor designs. In the MSFR, the liquid fuel is the coolant, which moves throughout the primary circuit. This complex phenomenology requires multiphysics modeling. In the present paper, a model of the MSFR is developed in the multiphysics code Cardinal, considering neutronic-thermal hydraulic feedback and the transport of delayed neutron precursors (DNPs) and decay heat precursors (DHPs). OpenMC is used to solve neutronic equations, and NekRS is used to solve mass, momentum, energy, DNPs, and DHPs distribution. A RANS k-t turbulence model is used in NekRS. DNPs and DHPs are modeled using a convective-diffusion equation with modified source terms considering radioactive decay. Cardinal results showed a reasonable behavior for temperature, heat source, velocity, DNPs, and DHPs. However, the current limitations in OpenMC do not allow the modification of delayed neutron source locations. Ongoing efforts look to include this feature in future work to introduce DNP feedback in OpenMC.

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Maximiliano Dalinger, Elia Merzari, Saya Lee, Casey Emler. 2025-07-05. High-Fidelity Modelling of the Molten Salt Fast Reactor. https://arxiv.org/abs/2507.04129

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