| 摘要 |
<p>An organic extraction phase, containing fission materials uranium and plutonium, as well as a minor amount of fission- and corrosion-products, from an extraction step or from a purification step of a nuclear fuel reprocessing process is treated with an aqueous, basic, carbonate ion containing solution, whereby the fission materials and at least a part of the fission- and corrosion-products are stripped into the aqueous phase and the uranium is present in the form of uranium-carbonato-complex. The organic phase is then separated from the aqueous phase. Plutonium is then removed from the separated aqueous phase. The remaining aqueous solution containing the uranium-carbonato-complex and a small residual amount (C) of fission products is adjusted to a ratio of uranyl ion concentration to carbonate ion- or CO3--/HCO3-- concentration of 1(UO2++) to 4.5(CO3-- or CO3--/HNO3-), respectively, or more, at a maximum U-concentration of not more than 6- g/l. The adjusted solution is then led over a basic anion exchanger made from a polyalkene matrix provided with a preponderant part tertiary and a minor part quaternary amino groups to adsorb fission product ions or fission products containing ions. The unadsorbed uranyl-carbonato complex which is now decontaminated, and preponderantly fission product free is recovered by separating the uranium containing, remaining aqueous solution from the ion exchanger.</p> |
