Task analysis of decommissioning activities in nuclear power plants

Reactor Pressure Vessel Internal is dangerous because of the highest radioactivity level among the decommissioning activities of Unit 1 of Kori, and because the dismantling operation of RPVI is performed in the water, depending on remote equipment and visual system, which occur a lot of human error possibility. Therefore, Task Analysis that should be important in the qualitative analysis of HRA is performed for RPVI decommissioning activities of Unit 1 of Kori. Task analysis, which is the initial step of HRA for human error reduction, was performed. TA format was established using HTA which is one of task analysis methods. The results of task analysis were derived by applying these to TA format. The results of the TA, the detailed planning, the difficulties during the work, the experience of the decommissioning, the physical environment (radiological environment, underwater operation) influenced the internal and external factors of the operator. Therefore, if these factors are identified and used, it will help to reduce the human error and to identify the cause