Abstract: Based on recent practical experience in the clearance control of slightly contaminated materials in China and in accordance with current national laws, regulations, standards, and relevant requirements, a clearance assessment was conducted for 102 temporarily stored barrels of waste activated carbon. Through source term analysis, radiation level measurement, sampling representativeness evaluation, and clearance assessment, the annual effective doses to workers and residents resulting from the incineration of the cleared waste activated carbon were estimated.Analysis results indicate that, under the premise of ensuring sampling representativeness, the optimal measurement time for radioactive waste activated carbon is 30,000 s, and the optimal sampling ratio is 50%. The activity concentration of radionuclides in the waste activated carbon samples complies with the deah release criteria outhined in GB 27742—2011.The annual effective doses to workers and surrounding residents during the incineration process of the cleared activated carbon meet the dose criteria for reuse processes.

Key words: nuclear power plants, activated carbon, clearance assessment