Development Of A Miniature Neutron Source Reactor Simulator For Training And Education

Abstract

This research project is aimed at developing a virtual dynamic simulator for a Miniature Neutron Source Reactor with GHARR-1 as a model. The GHARR-1 core which is surrounded above, beneath and around by metallic beryllium reflectors has undergone core conversion and now has a LEU core. The simulator modelled the reactor’s self-limiting transient behavior as well as the reaction to the control rod movement, thermal reactivity feedback and fission product poison build up during the normal reactor operation. Using the point kinetic model of neutronics, a simplified model of fission product poisoning and lumped parameter modelling of thermal hydraulic exchanges between different zones of the reactor, ordinary differential equations were developed for the time gradients of reactor power and the temperatures of the different reactor zones. These equations were solved with LabVIEW 2019 Control and Simulation Toolkit, using its Runge-Kutta 45 ordinary differential equation solver. The reactor control panel, built with the LabVIEW 2019 graphical user interface, allows the user to vary control rod position, and configure the differential equation solver parameter. Outputs of reactor inlet and outlet temperatures, fuel clad temperature and reactor power are displayed in simulation time and can be retrieved into a file. For simulation of reactor presets after control rod full insertion, the simulator depicted similar trends in output to those obtained by experiment. These values were however overestimated by the simulator by varying levels of deviation. The simulator was capable of qualitatively predicting the power, and temperature trends of the GHARR-1 at 17 kW and 34 kW.