Technologies for Removing Liquid Radioactive Waste in Radionuclide Therapy Departments

Relevance: In accordance with domestic regulatory documents for the management of medical liquid radioactive waste (LRW), in the units of radionuclide therapy (RNT) all LRW through special sewerage enter storage tanks, where they are kept for radioactive decay. Upon reaching the established standard for specific radioactivity, the accumulated LRW are discharged into the domestic sewerage system. However, due to the specificity of medical LRW with several different radionuclides, determining the optimal exposure time is a difficult task. Purpose: Analysis of existing and development of new technologies for managing the removal of liquid LRW in the subdivisions of the RNT of medical institutions. Material and methods: The advantages and disadvantages of the existing technology for determining the holding time of liquid radioactive waste in a storage tank based on the results of radiometry of periodically taken samples of liquid radioactive waste are considered. It is shown that it does not meet the requirements of reducing labor intensity and ensuring radiation safety of personnel of the RNT division. Six new technologies for managing the removal of liquid radioactive waste have been proposed, of which the recommended method for practice is based on a single dosimetry of γ-radiation from a filled tank with subsequent calculation of the exposure time to determine the moment of timely discharge of disintegrated liquid radioactive waste into the domestic sewerage system. Results: Using the proposed technology, the optimal moment for discharging the contents from the tank with liquid radioactive waste accumulated in it, which is radiopharmaceuticals labeled with 131I, 153Sm, 177Lu, removed from the body of patients, was determined. It is shown that the obtained dwell time value is significantly less than those established in the design documentation and in the protocol of the institution's radiation safety service. Conclusion: The developed method for controlling the removal of liquid radioactive waste is characterized by an accuracy acceptable for radiation-hygienic purposes while ensuring simplicity and low labor intensity of its practical application in RNT departments of domestic medical institutions