Method of recycling spent nuclear fuel

摘要

The method concerns processing irradiated (spent) nuclear fuel (SNF), it is primarily aimed at isolating and trapping tritium, and can be used in nuclear power industry for treating SNF. This method provides for a two-phase voloxidation of a reaction mass using gas-air mixture, the reaction mass including fragmented uranium dioxide SNF elements with containers. The first phase is carried out at 400-650° C. in the presence of air and additional carbon dioxide. The second phase is carried out at 350-450° C. using a stream of an air-vapor mixture that can be oxygen-enriched. Both phases are carried out with a repeated mechanical activation of the reaction mass. Provided in the course of the voloxidation is the gas replacement at the hour rate of about 10-50 fold the reaction chamber gas volume. Before being introduced into the reaction chamber, the gas is preheated up to the chamber internal temperature.

主权项

1. A method of volumetric oxidative treatment of spent nuclear fuel (SNF) of uranium dioxide, the method comprising thermal processing a reaction mass of SNF element fragments in oxidative environment, said thermal processing being carried out in at least one reaction chamber in two phases, the first phase being performed at 400-650° C. for 60-360 minutes in the gas stream of air additionally comprising carbon dioxide in the amount of 1-4 volume %, the second phase being performed at 350-450° C. for 30-120 minutes in the gas stream of air that includes water steam in the amount corresponding to the dew point of gas-vapor mixture at 30-40° C., the both phases being performed with a repeated mechanical activation of the reaction mass.