10th International Conference on Mechanical Technologies and Structural Materials, MTSM 2021, Split, Croatia, 23 - 24 September 2021, vol.2021, pp.129-132
© 2021 Croatian Society for Mechanical Technologies. All rights reserved.Neutrons are neutral subatomic particles and, similarly to other particles, protons and electrons, their potential applications fundamentally consist in research and development studies related to industry, medicine, agriculture and other fields. Production of radiopharmaceuticals, assessment of the humidity values of soil and characterization of materials' inner structure can be mentioned as examples of the wide area of employment of these special and spectacular particles. Beside these unique properties, human body should be protected against uncontrolled irradiation with neutrons due to their high ability of penetrating and causing indirect ionization, i.e. the most known dangers of these particles. Works for this purpose have been performed, focused on usable, economic, light weight and high strength shielding resources, and composites with layered or mixed type of different suitable materials are the favorite candidates. There are two steps in neutron shielding works: thermalizing and adsorption of neutrons are the main step, then the shielding of indirect ionization such as alfa, beta or gamma is the second step. Developed materials, thus, should be adequate for both steps. In the present work, we have investigated the shielding characteristics of concrete blocks reinforced with boron carbide and iron fillings in the field of Am-Be neutron source having 2 Ci activity. Boron carbide has a good reputation along with high thermal neutron cross section and high mechanical values. Concrete too is one of the basic component of constructional field. Energetic neutrons can be thermalized by collisions of light nucleus of concrete then absorbed by boron carbide. Iron fillings take place in the structure, in order to absorb gamma radiation which originated from the indirect ionization of neutrons. Within the scope of this study, 15 samples were prepared having 100×100 mm width-length values and a 20 mm thickness, with different percentage of boron carbide and iron fillings. According to the results from experiments, the highest (61.34%) and the lowest (20.83%) shielding rates were obtained respectively from the last and the first sample. An adequate indirect radiation shielding resulted from all samples. In the light of these outcomes, this material can be considered as an effective neutron shielding material.