| 摘要 |
FIELD: power industry. ^ SUBSTANCE: invention refers to separation methods of long-living radionuclides at complex processing of irradiated nuclear fuel (INF) of nuclear power plants (NPP) and is designed for selective removal of neptunium from combined extract of uranium, neptunium, plutonium and technecium. Method for neptunium removal during separation of long-living radionuclides involves extraction of uranium (VI), plutonium (IV), neptunium (VI) and technecium (VII) from nitric-acid solution with diluted tributyl phosphate and reducing re-extraction of neptunium (V). Selective neptunium re-extraction is performed before and after separation of technecium with peroxo-acid solution in weak nitrogen acid at content of 0.7-1.5 mol/l of nitric acid and 0.05-0.15 mol/l of peroxo-acid in re-extract. ^ EFFECT: invention allows obtaining neptunium re-extract not containing uranium, plutonium and technecium, thus improving selectiveness at neptunium stabilisation. ^ 3 cl, 1 dwg, 3 ex, 3 tbl |
