A Digital Twin-Based Approach to Noble Metals Deposition in the Molten Salt Reactor

This work presents a digital twin framework to study how noble metal fission products migrate and build up in molten salt reactors (MSRs). The model combines neutron transport, depletion, and material flow from Serpent 2 with system-level thermal–hydraulics from Modelica, connected through a Python interface. Deposition on surfaces and bubbles is described with 0-dimensional standard correlations, making the simulations flexible and fast compared to CFD. When compared with knowledge from MSRE, the framework shows similar deposition and decay heat trends, despite the great difference in U-235 and U-233 original data. For a commercial MSR case, the analysis looks at the post-draining scenario for the primary heat exchanger, which is assumed to be the most critical component. To address this, an experimental procedure is proposed using operational phase, zero-power decay, and low-power operation with sinusoidal power changes. The results show that this approach is expected to separate the heat from deposits without requiring a shutdown. Noble metal deposition is confirmed as a system-wide phenomenon with significant safety and economic implications.