METHOD OF REMOVING NUCLEAR FUEL FROM RESEARCH AND POWER REACTOR LOOPS Russian patent published in 2015 - IPC G21F9/30 

FIELD: physics, atomic power.

SUBSTANCE: invention relates to means of removing uranium dioxide used as nuclear fuel from coolant of primary and main loops of research and power reactors. In the disclosed method, the loops are treated with oxalate-peroxide solutions with pH=6.5-7.0. Treatment is carried out in a certain sequence of process steps which result in the complete dissolution of uranium dioxide.

EFFECT: tenfold increase in the rate of dissolution of uranium dioxide, which cuts reactor downtime, not without significant effect on structural materials of the loops and corrosive radioactive deposits on the inner surfaces of the equipment of the loops, which prevents disruption of steady-state heat-exchange between the coolant and the solid phase, and further increase in activity of liquid radioactive wastes.

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