Patent ID: 7011798

Claim:
A process for reprocessing spent nuclear fuels by utilizing phenomenon of cocrystallization comprising; a step of shearing spent nuclear fuels, dissolving sheared spent nuclear fuels into nitric acid to prepare a first nitric acid solution and removing insoluble residues in the first solution, a step of adjusting a nitric acid concentration of the first solution and adjusting a valence of uranium and plutonium in the first solution into hexavalence, cooling the first solution to crystallize uranyl-plutonyl nitrate hydrate crystals and separating the first solution into a first mother liquor and the uranyl-plutonyl nitrate hydrate crystals, and a step of dissolving the separated uranyl-plutonyl nitrate hydrate crystals again into nitric acid to prepare a second nitric acid solution, adjusting a valence of plutonium in the second solution into tetravalence, cooling the second solution to crystallize uranyl nitrate hydrate crystals, separating the second solution into a second mother liquor and the uranyl nitrate hydrate crystals, recovering the separated uranyl nitrate hydrate crystals as a uranium product and recovering the separated second mother liquor as a uranium-plutonium mixed product.