Advancements and research trends in the utilization technology of energy resources : Chapter4- Nuclear power

Nuclear power is positioned as one of the important technologies to achieve 'carbon neutral' in 2050. Nuclear power generation, which had been shut down since the Fukushima Daiichi Nuclear Power Station (1F) accident, has been gradually restarted. By the end of May 2023, ten reactors engaging in domestic nuclear power generation, which had been recognized as complying with the Nuclear Regulation Authority's new regulatory standards enforced in 2013, had been restarted. The government's basic energy plan and basic policy for realizing green transformation named the following as the next-generation innovative reactors: (1) innovative light-water reactor, (2) small light-water reactor, (3) fast reactor, (4) high-temperature gas reactor, and (5) nuclear fusion reactor. As of now, 12 years after the 1F accident, Units 1 to 3 reactors are maintained in a stable cooling state and total 1F is judged as generally maintained in a state of cooling shutdown. Regarding the decommissioning work of 1F, the International Research Institute for Nuclear Decommissioning (IRID) is taking a lead in conducting R&D on measures for contaminated water and treated water, preparations for fuel debris retrieval, and treatment/disposal of radioactive waste. As for the activities overseas, this review picks up development trend of new type reactors such as small modular reactor (SMR), and introduces the progress of major construction plans underway. Regarding the nuclear fuel cycle and radioactive waste disposal, this review summarizes the current state of uranium enrichment, reprocessing, radioactive waste disposal, etc. (A.O.)