An extension of the point kinetics model of MIPR to include the effects of pressure and a varying surface height

This work aims to expand upon a previous point kinetics model of an aqueous homogeneous reactor and make several additions to it including the effects of average pressure, plenum gas composition and temperature, vertical advection of solution due to voidage and thermal expansion and a neutron flux profile which varies in both time and height from the reactor base. It is found that these additions cause a small change to the reactor behaviour but the main advantage is to allow the modelling of different scenarios including failure of the gas management system which normally removes hydrogen and fission product gases from the plenum gas. Such a failure is seen to lead to a rapid increase in hydrogen content with implications for reactor safety. The model is also used to simulate the CRAC-43 experiment and, with the addition of simple models for the delay of radiolytic gas production due to the need to saturate the fuel solution and sloshing of the fuel solution, is found to approximate the experimental results well. (C) 2014 Elsevier Ltd. All rights reserved.