Proposal for Organizing and Understanding Decommissioning Information Using Task Ontology

Abstract In this study, we propose a hierarchical framework using task ontology, which is used in information science and information engineering, to organize decommissioning information. As background, decommissioning of nuclear facilities generally takes a long time, so it is important to accumulate information and utilize it. In decommissioning, the operator creates a plan using facility information during construction, subsequent renovations, and contamination distribution and evaluation during operation, and conducts decontamination, demolition, waste management, and waste delivery. It may also include restoring the land on which it was installed to its original condition. In addition, there are several implementation policies for this decommissioning: cases where the operating entity hands over the decommissioning to the decommissioning company, and cases where the operating entity directly carries out the decommissioning. Decommissioning is being carried out in each country and by various organizations, and various knowledge and lessons are being created every day. It is important to utilize these findings. On the other hand, it can be said that it is difficult to simply utilize it in other organizations due to different laws and regulations and different organizational management policies. It is necessary to appropriately utilize precedent cases and information on lessons learned. Therefore, in this study, we introduce the concept of ontology to decommissioning and propose a conceptual model from the perspective of plant information management and knowledge management. Ontology has guidelines for understanding objects without using language, and is a conceptual structure of knowledge. Previous studies and reports have referred to the importance of ontology in decommissioning, but it cannot be said that its structure and relationships with other ontologies have been specified. In this study, we propose a structural organization using task ontology as a guideline for information organization to cope with such situations.