Dynamic Model to Predict Reactivity Effects of Core Temperature Biasing in SLOWPOKE-2

Abstract

A mathematical model has been developed to simulate the behaviour of the SLOWPOKE-2 reactor for the purpose of assessing potential benefits and safety implications of core temperature biasing by auxiliary coo ling. The model considers relevant physical processes such as reactor kinetics and reactivity effects of temperature and xenon as well as heat transfer by natural and forced convection and conduction. Reactivity load as a function of time for constant power operation as well as the peak powers and core outlet temperatures during self-limiting power excursions are thus predicted. They are found to be in reasonable agreement with experimental data for the SLOWPOKE-2 reactor without auxiliary cooling. The simulations indicate that following implementation of auxiliary cooling, large increases in irradiation times will be possible without significantly compromising SLOWPOKE'S inherent safety.