Method of removing radioactive substance from radioactive solid waste storage pool

When spent fuels, control rods, channel box, etc. are disposed at predetermined positions in a storage pool for radioactive wastes, mesh type filters are usually disposed to a pool water recycling system thereby removing impurities in pool water mainly with an aim of improving the transparency of the pool water for enabling such operation safely and reliably. In accordance with the present invention, a cleanup device having ion removing performance is disposed for reducing radiation exposure in the operation about the storage pool. Further, for facilitating the exchanging operation in water even by remote control upon reduction of the performance of the cleanup device, mating portions of parts which require exchange upon reduction of the performance are constituted as one-touch joint. This can realize the reduction of the operator's exposure does during operation of the cleanup device and in replacing operation. (T.M.)