2015 年 14 巻 2 号 p. 128-139
Since there are many scenarios of the process from start to completion of a decommissioning project, it is important to study scenarios of decommissioning by evaluating such properties as safety, cost, and technology. An optimum scenario with the highest feasibility in accordance with the facility and environmental conditions should be selected on the basis of the results of the study. For analyzing a scenario of decommissioning, we prepared structured work packages by using the work breakdown structures (WBS) method together with qualitative evaluation of the technologies being applied to work packages located at the bottom (the third level) of the WBS. A calculation model was constructed to evaluate the feasibility of a scenario where fuzzy logic is applied to derive a score of technology performance and TOPSIS is applied for getting a feasibility grade of the scenario from technical performance scoring. As a case study, the model was applied to the debris removal scenario of Fukushima Daiichi Nuclear Power Plant to confirm its applicability. Two scenarios, underwater and in-air debris removal cases, were characterized by extracting the work packages with the lowest feasibility and by obtaining total average scores of the scenarios. It is confirmed that the methodology developed is useful for the scenario evaluation of decommissioning nuclear facilities.