METHOD AND DEVICE FOR RECOVERING REACTOR RADIOACTIVE GRAPHITE WASTES Russian patent published in 2002 - IPC

FIELD: nuclear power engineering; recovery of very active irradiated-graphite wastes of decommissioned water-graphite reactors. SUBSTANCE: method includes crushing of reactor graphite wastes, introduction of powdered aluminum into crushed wastes to function as energy carrier and carbide- forming element of titanium dioxide or dichromatic trioxide, as oxidant; introduction of mixture thus prepared into container with inert atmosphere under conditions of self-spreading high-temperature fusion by initiating mixture-components combustion reaction. Mixture also incorporates modifier chosen from materials which decompose and/or fuse at combustion reaction temperature of mixture components and do not enter in reaction with end product formed in the course of self- spreading high-temperature fusion. Mixture is placed in container and at least half of its open surface is covered with layer of igniting compound. Combustion temperature of the latter is minimum 2500 K. Igniting compound does not emit gaseous products. Thermal treatment is conducted in non-tight reactor at inert-gas gage pressure of 200-250 Pa without air admission. Graphite wastes recovery device has bin to receive crushed wastes, bins holding powdered aluminum, titanium dioxide or dichromatic trioxide, and modifier, and batcher for each of mentioned components. Device also has mixer, reactive mixture batcher, container, reactor and igniter, bin and batcher for igniting compound, and charge- discharge mechanism for moving container holding reactive mixture into reactor and taking it out of the latter. Reactor is provided with sluice chamber that has external and internal ports, filter communicating with reactor and used for entrapping carryover products formed in the course of self-spreading high-temperature fusion, inert gas feeder communicating with reactor and with sluice chamber, and device control panel. EFFECT: facilitated procedure, enhanced safety and reliability, reduced power requirement, enlarged mass of simultaneously recovered wastes. 6 cl, 1 dwg