GB/T 11844-2015 stipulates the method for determining the content of fluorine and chlorine in uranium dioxide powder and pellets, using high temperature hydrolysis-ion selective electrode method. The standard specifies the experimental steps, equipment requirements and Data processing methods. Through standardized operation, the fluorine and chlorine content can be accurately determined, which is of great significance to the mass control of uranium dioxide products. It provides a reliable basis for the production, research and development and mass testing of nuclear energy-related fields, and ensures the performance and safety of nuclear materials.