Mechanical behavior and neutron shielding performances of TiO2-incorporated cement composites

Abstract

Cementitious materials have been variously used in various nuclear facilities because of their cost-effective neutron shielding ability. In this study, the mechanical properties of cement paste containing nano-TiO2, which has a wide range of neutron reactivity cross-sections and a chemically-stable character was analyzed using compressive strength, density comparison, and pore distribution. The neutron shielding performance was quantitatively analyzed by the Monte Carlo N-Particle transport code (MCNP). The mechanical properties of the cement paste incorporated with 10 wt.% nano-TiO2 (T10) were found to be higher than that of ordinary Portland cement paste (T0) due to the filling effect of the nano-TiO2 by the compressive strength test and porosimetry analysis. Thermal neutron (0.025 eV), epithermal neutron (1 keV), and fast neutron (10 MeV) regions were exposed to the shielding walls, which were 5, 10, 20, 30, and 50 cm thick, comprising T0 and T10, by the MCNP simulation. As a result of these simulations, the shielding performance of T10 was higher than that of T0 at the thermal and epithermal neutron energy levels. As the thickness of the shielding wall increased, the effect of the neutron shielding ability also increased.