Indonesia Conference Directory

Indonesia has three research reactors which already old. So it is necessary to design new reactor core which is a compact core design, MTR type, utilizing low enriched uranium molybdenum dispersion fuel of high density. Optimization of neutron fluxes in irradiation positions is of great concern in research reactor design. The general approach used at the MTR reactor core for neutron flux optimization in irradiation position is presented. The approach is essentially based upon a optimization of the core configuration combined with the improvement of fuel characteristics. This simulation study was conducted by employing the standard reactor physics simulation codes WIMSD-5B and BATAN-FUEL. The present study is to analyze the effect of core configuration with the safety control rods and neutronic parameter by calculation using diffusion code. The MTR core consists of 16 fuel elements and 4 control rods put in 5 x 5 position of grids plate and by loading reflector elements outside the core. The aim of this research is to get the optimal design such as the highest neutron fluxes at the central flux trap position and also at irradiation positions in the core. Fuel cycle length of this core also becomes a concern, it is not less than 20 days and this core can be operated safely at the power of 50 MW. The result of calculation showed that for the lowest loading of fuel namely 450 gram of U7Mo/Al fuel with D2O as a reflector would provide higher neutron flux in center irradiation position of the MTR core namely 1.072 x1015 n/cm2s. Fuel cycle length of this core will reach 21 days, it meets the acceptance criteria and it will require less negative reactivity of control rods for its safe operation at 50 MW compare to other density