Development of a point kinetics model with thermal hydraulic feedback of an aqueous homogeneous reactor for medical isotope production

Abstract

This thesis presents the development of a model of the Medical Isotope Production Reactor (MIPR): a conceptual Aqueous Homogeneous Reactor (AHR). The model is a point kinetics model with zero and one-dimensional thermal hydraulic feedbacks. Three versions of the model of increasing complexity are presented and a number of scenarios are modelled with each version. The results of these simulations shows the stability of the reactor against reactivity insertions caused by the strong negative reactivity feedbacks inherent to AHRs. The first version of the model is modified using intrusive polynomial chaos in order to simulate the effects of uncertainty in key parameters. This allows a novel study into which physical parameters and processes are important at each stage of a transient and in determining steady state conditions. The final version of the model is used to model the CRAC-43 experiment and, after modification to include the delay of radiolytic gas production which accompanies the start up of an AHR, good agreement was found between model and experiment. The development of the equations, correlations and parameters used in the model is approached from the point of view of the governing physics. This approach to model development enables a comprehensive exploration of the physical processes underpinning the behaviour of AHRs. As well as being one of the most complete and fundamentally based models of an AHR presented within the literature, the final model is also extremely versatile and general. Given the appropriate input neutronic and thermal-hydraulic data the model presented in this thesis should be able to simulate a very wide range of AHR behaviour.