| 摘要 |
<p>PURPOSE:To decrease an insoluble residue by soaking a coolant provided with a cooling-down measure, into a solution in which spent fuels are dissolved, after th solution is regulated to have nitric acid concentration of 3 to 6 normal and of uranyl a nitrate concentration of 200 to 500g/l, and then by cooling down the solution. CONSTITUTION:In this reprocessing method, at a liquid regulation process 3, concentration of nitric acid is regulated to be 3 to 6 N or 3 to 4N, more prefer ably, and concentration of urainum is preferably regulated to be 350 to 400g/l. Then, the regulated solution is transferred to a depositting tank of a crystalliza tion process 4, a coolant is soaked into the solution in a condition not to contact with the inner wall of the tank, and the first stage crystallization process is performed. Subsequently, whole solution is cooled down to -10 to -30 deg.C or -10 to -20 deg.C, more preferably, to deposit a uranyl nitrate and a plutonium nitrate as a dendrite on the surface of the coolant. With the aforementioned first crystallization process, the uranyl nitrate and the plutonium nitrate deposit as dendrite on the surface of the coolant, and insoluble residue settle at the bottom of the tank and therefore almost all of the residue is removed from the solution.</p> |
