Summary of the Practice of Clearance of Uranium-Containing Calcium Fluoride Slags in China’s Nuclear Facilities

Abstract During the operation of some nuclear facilities in China, a large amount of uranium-containing and fluorine-containing wastewater will be produced, which requires de-uranium and de-fluorine treatment before discharge. The commonly used method for removing fluoride at present is the chemical lime precipitation method, that is, adding lime to fluorine-containing wastewater to combine fluoride ions with calcium ions to form calcium fluoride precipitation that is insoluble in water. This method has the advantages of low cost and easy operation, but it will produce a large amount of uranium-containing calcium fluoride slag. The content of CaF2 in these slags is more than 80%. If the uranium-containing calcium fluoride slag is cleaned and controlled and reused as a non-radioactive waste, it will not only use fluorine resources, but also eliminate the secondary pollution of fluorine. This article mainly introduces the clearance activities of uranium-containing calcium fluoride slags carried out by the nuclear facilities, including process conditions, source item investigation, waste sampling, nuclide concentration analysis, release control evaluation, release destination and quality Guarantee, etc., and provide relevant management and technical advice on the cleaning and control of uranium-containing calcium fluoride slag based on the above-mentioned practice.