Abstract:
A model of the Greek Research Reactor (GRR-1) core configuration was developed using the Monte Carlo code MCNP with continuous energy neutron cross-section data evaluations from ENDF/B-VI library. The model includes detailed geometrical representation of the fuel and control assemblies, beryllium reflectors, graphite pile and irradiation devices. In this work, the MCNP model of GRR-1 core was applied in order to predict the neutron field characteristics at a special in-core irradiation element, irradiation devices used for neutron activation analysis and radioisotope production and at the graphite thermal neutron column assembly. The MCNP estimated neutron flux was compared with measurements using gold foils with and without cadmium covers to obtain the thermal and epithermal neutron flux in the irradiation positions. A good agreement between calculated and experimental results was observed. Since experimental determination of the flux characteristics at the reactor irradiation devices is time and labor consuming, the developed model is a useful tool in predicting neutron flux in samples for purposes of designing and evaluating experiments involving material irradiations.