OBTAINING HYDROGEN FLUORIDE FROM URANIUM HEXAFLUORIDE IN COMBUSTION MODE

Abstract

Uranium hexafluoride, depleted in the isotope U-235 (DUHF), is a by-product of the isotopic enrichment of uranium in the nuclear fuel cycle, which is sent for long-term storage. Currently, there are no effective industrial technologies allowing to return fluorine into the technological cycle. The authors of the article propose a method for processing DUHF in a flame of hydrogen-containing fuel (for example, hydrogen) and oxygen, on the basis of which hydrogen fluoride and uranium oxides can be obtained. Using the program code of our own design and the ASTRA.4 complex, thermodynamic calculations of the equilibrium compositions of substances in the UFHO system of elements were performed and it was shown that if the number of hydrogen atoms exceeds the number of fluorine atoms, then in a thermodynamically equilibrium mixture at a temperature above 1150 K, the main fluorine-containing substance is hydrogen fluoride, and the main uranium-containing one is uranium dioxide. The specified temperature can be achieved by processing DUHF in a hydrogen and oxygen flame. This process was experimentally investigated on a pilot plant created by the authors and it was shown that the composition of its products is close to thermodynamic equilibrium. The results obtained can become the basis for industrial technology for the production of anhydrous hydrogen fluoride from DUHF.

Keywords

• depleted uranium hexafluoride
• uranium dioxide
• hydrogen fluoride
• combustion