Behaviour of high density concrete For neutron and gamma attenuation Characteristics at high Temperature regimes

Abstract

Gamma and neutron shielding in nuclear plants frequently uses newlineconcrete as one of the components. Several distinct varieties of concrete newlinewith varied densities and mixes are being utilized, depending on the newlineshielding requirements. Concrete is used because it is simple to fabricate newlineand inexpensive to build and maintain. Choosing the right mix of high newlinedensity aggregate and other materials that include hydrogen as newlinechemically bonded or adsorbed water is necessary to create a suitable newlinedesign that achieves maximal attenuation of neutron and gamma newlineradiation. newlineThere is a dearth of knowledge regarding shielding newlinecharacteristics at temperatures that are sustained over 100°C (the boiling newlinepoint of water), which are typical of reactor environments. newlineThe objective is to study the effect of elevated, sustained and newlinecyclic temperature on Mechanical properties, Neutron and gamma newlineattenuation characteristics of high density concrete. Concrete samples newlinewith addition of granite aggregate (A), hematite aggregate (B), and newlinehematite with steel shots (CandD) of varying densities was used. Micro newlinechemical changes of high density concrete specimens were also studied. newlineNormal density concrete when subjected to sustained newlinetemperature of 65°C, 75°C and 90°C were not showing any changes in the newlinedensity beyond 50 days. In the present study, various mix design of newlineconcrete of various densities was obtained by addition of materials like newlinegranite, hematite and steel shots. Initially evaluation of baseline newlinemechanical properties, neutron attenuation, gamma attenuation of these newlinevii newlinemix design concrete were obtained at normal temperature. Then thermal newlineaging of these samples were done at sustained temperature of 120°C for newline14, 28 and 56 days. These mixes were also subjected to cyclic newlinetemperature using thermal cyclic chamber. Once again, evaluation of newlinemechanical properties, neutron attenuation, gamma attenuation was newlinestudied in the concrete samples after thermal ageing at various above newlinementioned temperatures. Microstructure evaluation of all these various newlinesamples of concre