A neutronics-fuel coupling model for the simulation of constituent redistribution in U–Zr fuel

Simulating the dynamic redistribution of elements within metallic fuels, such as U–10Zr (wt.%), is a complex challenge in nuclear power research. While existing models can adequately simulate constituent redistribution throughout the fuel pin, they rely heavily on pre-known power history data or power calculated a priori. Furthermore, existing models do not calculate an accurate actinide inventory throughout the fuel pin. This limitation leads to less precise power distribution calculations, which can negatively affect the efficiency and safety of fuel design and performance. This work aims to introduce a new approach to modeling constituent redistribution for U–10Zr (wt.%) fuel by developing a new code called PFPS that accounts for the depletion and diffusion of Zr throughout the fuel pin during burnup through an explicit coupling method. The approach independently calculates the power distribution by coupling with the reactor physics code, Serpent 2, thereby eliminating the need for externally supplied power history data. The main contribution of this study lies in this coupling to obtain a more accurate history of the compositional evolution of U–Zr fuel and its fission products. This procedure can enhance the understanding of constituent redistribution by calculating a more accurate power distribution and lays the foundation for future attempts to simulate the compositional and microstructural evolution of all materials in the fuel.