Dispersion Properties of B4C Microparticles as Emergency Neutron Absorbers in Spent-Fuel Pool Water

摘要

The dispersion properties of boron carbide (B4C) microparticles in aqueous media were investigated by measuring the particle size distribution, the dispersibility, and the zeta potential as these properties relate to their application as neutron absorbers in fuel-storage pool water. The B_4C powder is composed of particles with a narrow size distribution, with a d_(50) (mean diameter) of 0.65 μm. The amount of B_4C particles dispersed decreased exponentially with increasing dispersion time. The dispersibility of B4C particles increased with an increase in the loading of B_4C particles and reached a maximum value at 12.91 wt%. The zeta potential of the B4C suspension was measured as a function of pH and temperature. The B4C suspension has a negative zeta potential value in the pH range between 2 and 12. The dispersion of B4C particles was not greatly influenced by the addition of boric acid (H3BO3). The absolute value of the zeta potential decreased with increasing temperature.