| 摘要 |
PROBLEM TO BE SOLVED: To provide a method capable of separating Am which contains no Cm and from which most of a fission product FP is removed from a high level radioactive waste containing FP, Cm and Am, which is efficiently executable in a short time compared with a conventional ion exchange method and remotely controllable. SOLUTION: This method comprises a process of adding sodium bismuthate powder while retaining a nitric acid solution containing FP, Cm and Am at 0 deg.C or lower to oxidize the Am in the nitric acid solution to Am (VI), the process of adding a phosphoric ion solution and a bismuth (III) (Bi (III)) solution while retaining the nitric acid solution at 0 deg.C or lower to precipitate bismuth phosphate and filtering the generated precipitate after the coprecipitation of Cm and most of FP to separate the filtrate containing Am; the process of adding iron nitrate (III) solution to the filtrate, setting pH to 7 or more with sodium hydroxide solution to dissolve the generated precipitate of ferric hydroxide, and then treating the solution with an anion exchange resin and a cation exchange resin to remove impurities, thereby providing an Am solution from which Cm and most of FP are removed. This method is suitably usable as a method for separating Am for isotope analysis of Am contained in high level radioactive waste. |
