Verification of reliability of the burnup for PWR spent fuel of OPR1000 type

Abstract

As the saturation of spent fuel pool (SFP) capacity for nuclear power plants starting in 2030 is imminent, the operation of dry storage facilities for spent fuel from pressurized water reactors (PWR) has become urgent. Therefore, it is essential to secure characteristic data on the spent fuel and develop related equipment before these dry storage facilities begin operation. Due to the challenge of inspecting the spent fuel once it is loaded into dry storage casks, it is necessary to identify the characteristics of the spent fuel in advance and secure the information required for the transfer criteria for interim storage and disposal in the future. In particular, among the characteristics data, the burnup of spent fuel is one of the important management items not only for dry storage but also for transportation and disposal. Such burnup varies depending on the operating history, and in reality, nuclear power plants measure and manage the burnup using an in-core instrument (ICI) during operation. This study was conducted to verify the reliability of the burnup of such spent fuel. To this end, comparisons and analyses were conducted among the actual burnup obtained from the power plant, the design burnup calculated from design codes, and the measured burnup of spent fuel actually stored in the storage pool using burnup measuring equipment. This study aimed to establish an evaluation system for the long-term integrity assessment of spent fuel through burnup measurement and comparative analysis for the first time in South Korea, laying the foundation for systematic management.