Abstract: The operational intervention level is based on the principle of radiation protection optimization. It uses environmental monitoring data to implement response actions, so that protective actions meet actual emergency needs. As an important basis for emergency response, the operational intervention level is, therefore, a key link in the spent fuel reprocessing plant emergency plan. According to the characteristics of reprocessing plant operational intervention level, we adopt two methods to derive it's value, with the avoidable dose and the expected dose employed respectively. With the avoidable dose used as the protective action criterion for concealment and eevacuatio, the calculated value of OIL1 for the operational intervention level of serious accidents in reprocessing plants is very small, and below the detection limit of commonly used gamma dose rate meters. Taking the Russian Tomsk red oil explosion accident as the source term, we obtained the values of OIL₁, OIL₂ and OIL₃ using the method of avoidable dose. It can provide guidance for off-site public protection actions, improve emergency preparedness and management, in reprocessing plants.

Key words: Nuclear emergency response, Reprocessing plant, Operational intervention level