Neutronic modeling and calculations of the ETRR-2 MTR reactor using COMSOL multiphysics code

Abstract

The second Egyptian Test and Research Reactor (ETRR-2) is a 22MWth light water cooled and moderated open pool multipurpose reactor, with isotope production, thermal neutron scattering, neutron activation and materials irradiation capabilities. COMSOL Multiphysics is powerful finite element computational tool with diversified physics and engineering applications, and coupling phenomena capabilities, a feature that is very attractive for simulating nuclear reactors as well as neutronics and thermal-hydraulics calculations. In this work, a full core, three-dimensional, multi-group model of ETRR-2 reactor is developed using detailed specifications and quality experimental data from IAEA Technical Report Series. This paper presents COMSOL-based neutronics calculations performed to study reactor physics parameters. The WIMS-D5 with 69-group neutron cross section library, was used to calculate the five-group constants for different reactor regions essential to solve the diffusion equations. The multi-group constants were applied in the COMSOL model to perform neutronics calculations using adaptive mesh refinement technique to increase the accuracy of the solution. The calculated effective multiplication factor (keff) for three specified cases compare well with experimental measurements. The study found a slight difference between the calculated $8.70 excess reactivity and the measured value of $9.11 for the core. The calculated reactivity worth of CR-1 at different positions, are in agreement with experimental measured values. The spectrums of thermal and fast fluxes were also calculated by the COMSOL model and are presented in this paper.