Abstract: In-drum drying treatment of simulatedconcentrates was conducted at variable temperatures to identify the activity concentrations and distribution of nuclides loaded in offgas during treatment of radioactive waste generated from a NPP. The result has shown that there exist detectable contents of Sr, Cs, and Co in concentrated liquid and washing liquid, with growing decreased activity concentrations with decreased drying temperatures.The loading ratios of Sr, Cs, and Co are respectively 5.14%, 0.06% and 0.05% under the boiling condition, mostly in washing liquid, whereas 2.38%, 0.03% and 0.02% respectively under non-boiling condition.

Key words: Nuclides loading, In-drum drying, Radioactive liquid concentrates