Device of removing depositions on the surface of fuel assemblies

Purpose: To wash out surface depositions of fuel assemblies surely and efficiently in a short time without dismantling the fuel assemblies, using resin particles flashing methods. Constitution: Water containing synthetic resin particles is forcedly flown through the coolant path in the fuel assemblies, in which the synthetic resin particles perform the similar function as that of sand particles in the known sand flash process to mechanically remove the depositions. The synthetic resin used is such one as not injuring the surface of the fuel cans and not giving adverse effects in the reactor operation if incorporated by small amount in the cooling water. Polyacetal resin particles are used, for example. (Ikeda, J.)