METHOD FOR DECONTAMINATION OF GRAPHITE RADIOACTIVE WASTES Russian patent published in 2020 - IPC G21F9/34 

FIELD: technological processes.

SUBSTANCE: invention relates to processing of materials with radioactive contamination. Method of decontamination of graphite radioactive wastes includes arrangement of deactivated element in sealed chamber, connection of electrically conductive material with different poles of current source, circulation of aggressive working agent. Non-fragmented irradiated graphite element is used as an anode and placed on a thin grid. Cathode used is a housing of an electrolysis cell mounted on a ring-shaped permanent magnet. Deactivating solution containing (3-6) M HNO₃ with addition of 0.1 M KMnO₄ is introduced into the cell of the electrolysis cell, and constant electric potential is supplied to electrodes. Graphite element is dissolved to form a residue in a deactivating solution, which is removed from the electrolysis cell and concentrated in an evaporation vessel, the temperature of which is maintained in range of (83–88) °C. Part of concentrated solution is sent to distiller, in which it is cooled to temperature below (80–83) °C, after which it is returned to electrolysis cell before new cycle of process.

EFFECT: invention reduces the time required for the process and the amount of secondary radioactive wastes formed.

1 cl, 2 dwg, 1 ex