METHOD FOR RECOVERING NITRIC ACID FROM TRITIUM-CONTAINING GAS STREAM Russian patent published in 2018 - IPC G21F9/02 B01D53/00 

FIELD: chemistry.

SUBSTANCE: invention relates to radiochemical technology, in particular to a process for the recovery of nitric acid from a tritium-containing gas stream, and can be used in spent nuclear fuel processing for gas cleaning operations. Method includes absorption of radioactive components of a gas stream on the nozzle of column-type apparatus by a circulating aqueous stream prior to accumulation in the nitric acid solution to a concentration of 5 mol/l, distilling iodine from the absorbing solution by reducing the iodic acid with hydrogen peroxide and blowing molecular iodine on the nozzle with a stream of air, thermal breakdown of excess hydrogen peroxide by heating the adsorption column to a temperature of 70–95 °C, introducing into the heated nitric acid solution a reducing agent in the form of oxalic acid, catalytic reduction of nitric acid in the solution stream on a solid phase catalyst and oxidation of the nitrogen oxides evolved in the gas phase on the nozzle to nitric acid by spraying the gas stream with a solution of hydrogen peroxide.

EFFECT: invention provides the recovery of tritium-free nitric acid, and also allows to separate iodine into a separate stream and concentrate tritium, cesium and ruthenium in a solution with low acidity.

10 cl, 2 dwg, 1 ex