Evaluation of Salt Particle Collection Device for Preventing SCC on Canister: Effect on Particle Collection Rate by Electric Field

摘要

Now, in Japan, while metal casks are used for spent nuclear fuel storage, a practical use of concrete casks is under review because of its cost effectiveness and procurement easiness. In reviewing the practical use, stress corrosion cracking (SCC) of a canister container in the concrete cask becomes an issue and is needed to be resolved soon. In this study, we proposed a salt particle collection device with low pressure loss which does not interfere with the air flow into the building or the concrete casks. Pressure loss tests in a laboratory and salt particle collection tests in the field have been performed. It has clarified that the pressure loss of the device is one-thirtieth to one-twentieth of that of a commercial filter and 40% of the particles in the air could be collected and the device would not influence the heat removal performance. In the recently study, It was found that NO_3 and SO_4 like air pollutants were about 50% included in the air according to experiments. Moreover, we evaluated the effect of electric field on the particle collection under supposing the particle charge. In the case of electric field over 10~3kV/m the particle collection rate could be improved dramatically.