Patent clustering and network analyses to explore nuclear waste management technologies

In this study, we investigated the changes in those technologies over time in the United States, European countries, Japan, and China, all of which have led the global nuclear energy industry. Using clustering analysis based on the patents that were applied to those regions from 1972 to 2014, we first identified 15 technological topics in nuclear waste management. Next, using technology network analysis, we examined the changes in these topics over time. The results show that regional conditions such as the history related to nuclear weapons, type of ideology, geological condition, resource situation, and international affairs are critical factors that influence the trends in nuclear waste treatment technologies. We revealed that majority of technology development is concerned long-term storage. This method can be useful for both the advanced countries and the latecomers. However, as the long-term storage is not final step in nuclear waste management, those late comers should gain technological competence for nuclear waste management by not only in-house R&D but also open innovation via licensing or joint R&D with the advanced countries to complete technologies for overall life-cycle of nuclear energy.