Abstract: Uranium containing CaF₂ sludge is one of the important wastes in the nuclear fuel cycle, and generally it’s required to be relieved from the nuclear regulatory control. According to the characteristics of uranium containing CaF₂ sludge and theoretical calculation, the technical control conditions of radioactivity concentration of uranium containing CaF₂ sludge in the production and waste water treatments were acquired. To ensure the clearance of uranium containing CaF₂ sludge, the discharge quantity (V) of the main production process waste water and the mass concentration (C₁) of uranium in waste water entering into the precipitation process should be controlled to make sure VC₁<723 g in the nuclear fuel assembly manufacturing plant. Meanwhile, the monitoring emphasis should be put on the measurement of uranium in the precipitation process, with assistance of uranium measurement in the fluoride sludge. And for recycle and reuse of uranium containing CaF₂ sludge, the clearance procedure and a long-term programme should be standardized.