METHOD FOR DISSOLVING IRRADIATED MATERIALS CONTAINING TRANSURANIUM ELEMENTS, INCLUDING IRRADIATED NUCLEAR FUEL FOR DESTRUCTIVE RADIOCHEMICAL TESTING Russian patent published in 2021 - IPC C01G56/00 G21C19/46 

FIELD: nuclear technology.

SUBSTANCE: invention relates to nuclear technology, predominantly to analytical support of the process of recycling irradiated nuclear fuel and isolating minor actinides for subsequent burning. A sample of irradiated nuclear material containing transuranium elements, including irradiated nuclear fuel, is dissolved in a conical Erlenmeyer flask with a volume of 500 ml, with a reflux column with a height of at least 150 mm, connected in series with three traps constituting Petri absorbers. The first Petri absorber is intended for capturing ruthenium flying off on dissolution of the tested sample and comprises a solution of 0.05 mol/l nitric acid, the second and third absorbers are intended for capturing ¹⁴C released in the form of carbon dioxide, containing a solution of 1 mol/l sodium hydroxide. The volumes of the solution in all Petri absorbers are at least 30 ml. The sample is dissolved in 250 ml nitric acid with a concentration of 8 mol/l while heating to a temperature of 95 to 100°C for 16 hours and constantly purging the solution volume by an ozone-air mixture containing 5 wt.% O₃ at a rate of 1.2 l×h^-1, followed by cooling the resulting solution to ambient temperature.

EFFECT: method allows for quantitative determination of volatile fission products, including carbon-14, tritium, ruthenium isotopes, in the analysed sample.

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