A nonlinear dynamic model for the Aircraft Reactor Experiment: Experimental validation

We propose a dynamical compartmental model of the molten salt reactor in the Aircraft Reactor Experiment, and we assess its accuracy based on steady state and transient experimental data. We use modified point reactor kinetics equations to describe the power generation in the reactor core, and we model the thermal dynamics of the eight counter-flow heat exchangers using two compartments for the primary and secondary fluids and one compartment for the tubes. The core is modeled similarly with an additional compartment for the moderator. For the steady state experiments, we compare model predictions to experimental data for reported values, empirical estimates, and least-squares estimates of the thermal contact conductances and reported values of the thermal reactivity feedback coefficients. For the transient experiments, we use least-squares estimates of the thermal contact conductances together with reported values, estimates based on neutron flux Monte Carlo simulations, and least-squares estimates of the feedback coefficients. The accuracy of the model is low when using reported values for both the steady state and transient experiments, and in contrast, it is high when the model is fitted directly to the data using least-squares estimates. Furthermore, the steady state is predicted with acceptable accuracy for empirical estimates of the thermal contact conductances and reported values of the feedback coefficients, and the transient is also predicted with sufficient accuracy for least-squares estimates of the thermal contact conductances and estimates of the feedback coefficients obtained with Monte Carlo particle transport simulation. • Dynamical compartmental model of the Aircraft Reactor Experiment (ARE). • Estimates of thermal contact conductances and thermal reactivity feedback coefficients. • Comparison of model predictions with experimental steady state and transient data.