Solidification processing method of spent ion exchange resin by water curable material and device therefor

When dehydrated spent ion exchange resins are solidified by water curable materials, the amount of water to be added from the outside is determined based on the amount of water discharged from the ion exchange resins into the water curable materials. In order to determine the amount of water to be added, the amount of water to be released from the resins is estimated based on the amount of the dehydrated spent ion exchange resins and the water content thereof or the amount of water contained therein. The viscosity and the temperature of the products to be mixed are measured, and water is added depending on the measured value. In this way, since the amount of water to be added upon mixing is determined while considering the amount of water released from the spent ion exchange resins to the water curable products, the effective weight ratio of water/water curable products can be set to a predetermined value. Then, farm solidification products with suppressed radioactivity leaching can be obtained. (T.M.)