Abstract: The volume reduction of waste concentrates from NPPs is a required part of the radioactive waste minimization. This paper introduces the design and development of the self-developed in-drum drying process and its prototype. Debugging had been carried out to each individual section, unit and to the whole process, with a cold test at last using simulated concentrates. Experiment results show that the equipment is safe and reliable with a volume reduction ratio about 4% and product humidity about 15%, the concentrates from NPPs can be properly disposed by the in-drum drying equipment

Key words: waste concentrates, in-drum drying, radioactive, drying equipment