Abstract
Radiation safety aspects had been as a high impact parameter in design and setting up of neutron radiography (NR) facility for Tehran Research Reactor (TRR). For designing an optimized composite shield for neutron shielding in shutter, selecting the neutron absorber and composite matrix are the key elements. For this purpose, boron among the neutron absorbents, and epoxy resin as a matrix, for its specific characteristics, are more concerned. In this investigation, thermal neutron shielding ability was calculated theatrically for four boron compounds, including boron carbide, boron nitride, boron trioxide and acid boric. Indeed, by using Monte-Carlo simulation an innovated setup was introduced with high efficiency for thermal neutrons shielding. The results indicate the high efficiency of boron carbide absorbent in comparison with other boron compounds, as well as utilizing an increasing gradient neutron absorbent concentration in neutron shielding ability.