PREDICT-HT · FROM CORRELATION TO CAUSATION: A First-Principles Framework for Predicting Heat Transfer Deterioration

Heat Transfer Deterioration (HTD) is a critical, unresolved phenomenon that risks the safety and efficiency of next-generation nuclear reactors, directly impeding EU decarbonization goals. Current models fail predictively because they correlate HTD with flow oscillations without establishing causality. This project, “PREDICT-HT,” tests the central hypothesis that pressure variations caused by flow oscillations are the fundamental trigger for HTD. The experienced researcher (ER) will achieve this by integrating targeted experiments with advanced theoretical analysis, leveraging the host’s unique Spectral Element Method (SEM) solver to accurately simulate the transient physics of two-phase flow instabilities. This approach will: 1) quantify critical pressure-oscillation thresholds for HTD initiation, 2) establish a novel, physics-based stability criterion across boiling regimes, and 3) develop the first predictive model of the pressure-driven mechanisms that destabilize coolant films. Deciphering these mechanisms will enable stable operation of high-heat-flux systems, improving heat-transfer margins by 8–10% and reducing global CO2 emissions by tens of millions of tonnes annually by 2040. This fellowship, with secondments at Westinghouse Electric Sweden and Safetec Norway, will transform the ER's profile by providing decisive training in experimental methodology, complementing existing numerical expertise, to create a versatile leader in energy technology research.