METHOD OF REDUCING RADIOACTIVITY OF SPENT GRAPHITE BLOCKS AND APPARATUS FOR IMPLEMENTATION THEREOF Russian patent published in 2020 - IPC G21F9/28 

FIELD: technological processes.

SUBSTANCE: group of inventions relates to means of processing irradiated graphite blocks of uranium-graphite reactors and can be used in nuclear industry. Exhausted graphite block is placed into vessel and then object is subjected to irradiation with unipolar electromagnetic pulses with power of more than 1 MW and duration of less than 1 ns, repetition frequency is not less than 1 kHz. Exposure of the object is carried out in the vessel by means of electrodes connected to the source of said pulses, the object is treated for 10–30 minutes, and the spent graphite block is used as one of the electrodes. After treatment, the radioactivity of the processed block is checked for its reduction and, if necessary, repeated its treatment and radioactivity control one or several times until obtaining its acceptable value. Then, this block is removed from vessel and another graphite block is installed as electrode. Plant for reducing radioactivity of spent graphite blocks comprises hollow housing 1, detachable along longitudinal axis, with electrode 2 arranged in housing central part, located outside housing 1 and connected to it by one of terminals, and by the second lead with electrode 2 generator 3 of unipolar electromagnetic pulses with power of more than 1 MW, duration of less than 1 ns and repetition frequency of not less than 1 kHz. At that, housing 1 is located horizontally and is made of current-conducting material - copper sheet.

EFFECT: technical result is possibility of efficient processing of spent graphite blocks to reduce their radioactivity.

2 cl, 2 dwg