COMPUTATIONAL FLUID DYNAMIC MODEL OF TRIGA MARK II REACTOR

The objective of this work is to build a thermo-hydraulic model of the natural circulation flow in TRIGA Mark II research reactor at the Jozef Stefan Institute (JSI) by using computational fluid dynamic (CFD) code. Indeed, CFD is a very accurate tool describing fluid flow mechanics by solving numerical algorithms. This work is a step of a project aiming to build a computational model of TRIGA Mark II pool type research reactor coupling thermal-hydraulics and neutron physics in order to see how each one influence each other and what are the main parameters involved in this process. Whereas TRIGA at JSI was studied in great detail from neutron physics point of view, models describing flow pattern inside the reactor tank do not exist. Indeed, such model is not needed from a safety point of view; however, the benefit of such research is to establish an accurate benchmark test for coupled thermal-hydraulics and neutronic models. Starting from a given power distribution, which has already been established as a main input from neutron physics model, output such as temperature distribution and velocity field are computed. In the paper, the current status of the model is presented (geometry, mesh, boundary conditions.); verification and validation are made with data collected during some of the experiments performed at JSI.