Reliable Load Match Operation of MHTGR Power Plant: A Probabilistic Operating Space Approach

The advanced modular high-temperature gas-cooled reactor (MHTGR) power plant is a novel nuclear power system developed in China. To ensure load match and system safety of the MHTGR power plant, this paper investigates operational feasibility under uncertainty by introducing a concept of probabilistic operating space (POS), which is characterized by the envelope of operations that provides assurance of control performance with desired reliability. A model-based approach is proposed to efficiently identify the POS, considering hybrid uncertainties of process variability and model mismatch. First, Sobol sensitivity analysis and parameter estimation are applied for uncertainty quantification. Second, the hybrid uncertainties are propagated by a polynomial chaos expansion surrogate with parameterized coefficients. Furthermore, nested sampling is employed to allocate operating samples towards regions of high feasibility probability. The resulting POS is finally visualized as a probability map using geometric projection. Simulation results not only validate the effectiveness of the POS approach in identifying reliable load match operations but also highlight its computational efficiency.