METHOD AND PLANT FOR RECYCLING OF SPENT NUCLEAR FUEL Russian patent published in 2009 - IPC G21C19/48 

FIELD: fuel systems.

SUBSTANCE: invention is related to recycling of return nuclear fuel (RNF) and materials of blanket region (BR) of fast breeder reactors (FBR) for their multiple use with the possibility to adjust content in creation of a new fuel composition. Initial chemical state of processed material may vary: oxides, nitrides, metals and alloys. Method represents a combination of serial processes of chemical transformation of radiated nuclear fuel (RNF): fluoridation with gaseous fluorine and extraction of main uranium mass; transition of fluoridation remains into oxides (pyrohydrolysis); - chlorination of oxides in recovery conditions with group separation of plutonium chlorides, uranium (left in process of fluoridation) and fission products. Further "plutonium" and "uranium" fraction, and also fraction containing fission products (and, possibly, minor-actinides), are used each separately in various processes according to available methods. Earlier produced uranium hexafluoride, with low boiling fluorides of fission products, is cleaned from the latter and used, according to objectives of processing, also by available methods. Using waterless processes with application of salt melts, suggested version makes it possible to realise continuous highly efficient processes of fuel components production, moreover, it is stipulated to carry out preparation stages in continuous mode. Plant for processing of spent nuclear fuel containing uranium and plutonium includes three serially installed devices: fluoridiser; pyrohydrolysis device; chlorinator-condensator-granulator device. Two last devices are of flame type. The last of devices represents a pipe with a central element, in which lines of inlet product and reagents supply are installed. In lower part there is an expansion in the form of pear with a flame burner along its axis, and medium part has a row of conical shelves inside, between which there are nozzles with pipelines for chlorides outlet. Nozzle for chlorides outlet is also arranged in lower point of pear-like part. Nozzle for exhaust of non-condensed gases is provided in upper part. Granulator is arranged as reservoir with low boiling incombustible liquid, and to produce drops, capillaries are provided at pipeline ends.

EFFECT: highly efficient method for processing of spent nuclear fuel of practically any composition from thermal reactors and fast breeder reactors, blanket region of fast breeder reactors and some other types of reactors with the possibility to produce several other types of fuel compositions.

19 cl, 3 dwg