CRITICALITY CONTROL METHOD OF OF NUCLEAR SPENT NUCLEAR FUEL USING RARE EARTH WASTE FROM PYROPROCESSING

摘要

PURPOSE: A critical control method for used nuclear fuel using rare earth waste in a pyro process is provided to reduce the volume of high level radioactive waste and facilitate the recycling of the waste, by replacing expensive imported boron alloy steels. CONSTITUTION: From the waste eutectic salt generated in a pyro process, rare earth elements are separated. The separated rare earth elements are injected into a used nuclear fuel storage facility and used as critical control materials. The rare earth chloride remaining in the waste eutectic salt is converted into an oxide and is delaminated and extracted separately from the pure salt, leaving the rare earth oxide (Re2O3)(12). The rare earth elements are stored in a hollow cylindrical neutron absorber. The size of the hollow of the neutron absorber is flexible, and the radius of the hollow of the neutron absorber is 0.2 cm and 1.0 cm.