Reactor kinetics applied to LFR technology

Ensuring the safety of advanced reactor designs is one of the central challenges in developing next-generation nuclear technologies. Among these, Lead Fast Reactors (LFRs) stand out as promising candidates within the Generation IV portfolio, offering high efficiency and sustainability. However, their robust safety demonstration remains essential.

This PhD project focuses on a critical component of reactor safety: Reactor Kinetics, the study of how neutron population, and therefore reactor power, evolve under transient conditions. These dynamics drive the balance between heat generation and removal, which is vital for maintaining the structural integrity of reactor components during transients and accidental scenarios.

Unlike conventional Light-Water Reactors, LFRs lack operational experience, making computational modelling the primary tool for their safety analysis. The challenge is to develop a methodology that is both scientifically rigorous and practical for safety and licensing efforts. Current transient analysis approaches often rely on legacy codes that are complex, inflexible, and poorly suited for innovative designs. This project aims to overcome these limitations by systematically comparing Reactor Kinetics models - from simplified Point Kinetics to more detailed Space Kinetics approaches – and by integrating high-fidelity neutron physics calculations performed by Monte Carlo methods to generate accurate Reactor Kinetics parameters for such models.

This research will quantify how different modelling choices affect key neutron-physics and safety-relevant Figures of Merit and, in doing so, establish a methodology that ensures correct representation of physics and simplicity in modelling, while maintaining conservatism required for safety demonstration. Ultimately, this work will provide the foundation for transient analysis of LFR cores and support the nuclear licensing of the Belgian LFR demonstrator, LEANDREA.

If you are motivated by complex modelling challenges, nuclear innovation, and contributing to a safer energy future, this PhD offers a unique opportunity to combine theoretical rigor with practical impact - while gaining expertise in reactor physics, advanced numerical methods, and high-performance computing.