Approaches to The Establishment Of Safety Conditions For The Fuel-Containing Materials During New Safe Confinement Operation

Construction of the New Safe Confinement (NSC) above the Shelter over destroyed Chornobyl NPP Unit 4 has been completed. The NSC design is based on boundary conditions for current and potential hazardous impacts of the Shelter. Accordingly, criteria for Shelter safe state have to be established, in particular, criteria for the safe state of fuel-containing material (FCM) accumulations. The paper presents the results of the development of methodological recommendations for the establishment of acceptance/non-acceptance criteria of FCM accumulations with regard to safety, as well as on the FCM monitoring scope in order to monitor the extent of compliance of FCM state with the established criteria.