Twenty-seven reactors are so far earmarked or undergoing decommissioning and the decommissioning of nine has been approved by the regulator.
The nine are Genkai-1, Hamaoka-1, Hamaoka-2, Ikata-1, Mihama-1, Mihama-2, Shimane-1, Tokai-1 and Tsuruga-1.
Among the reactors earmarked for decommissioning are four at the Fukushima Daiichi nuclear station that were severely damaged by the earthquake and tsunami.
The annual nuclear white paper, adopted by the Japan Atomic Energy Commission, urges utilities to learn from US and European examples, especially those of Germany, France and the UK.
Japan has not yet completed the decommissioning of any reactors and does not have concrete plans for the final disposal of radioactive waste.
“Taking into consideration further increase of nuclear facilities that will be decommissioned, new technology and systems need to be developed in order to carry out the tasks efficiently and smoothly,” the report said. “It’s a whole new stage that we have to proceed to and tackle.”
Japanese utilities have opted to shut down many aged reactors instead of investing in safety requirements under post-Fukushima standards.
According to reports in the Japanese press, the decommissioning of a typical reactor costs over $550m and takes several decades.
There are 62 commercial nuclear power units in Japan, of which nine have passed stricter safety checks and restarted since the 2011 Fukushima-Daiichi earthquake and tsunami. The International Atomic Energy Agency lists 37 as potentially operational, 23 as permanently shut down and two – Ohma and Shimane-3 – as under construction.
Japan shut down all operational nuclear reactors after Fukushima-Daiichi. At the time of the accident there were 42 units in operation.
According to the IAEA, the country’s nuclear share in 2017 was about 3.6%. Before Fukushima, Japan generated about 30% of its electricity from nuclear and planned to increase that to 40%.
A recent energy white paper adopted by the Cabinet called for further efforts to cut carbon emissions by keeping to a nuclear generation target of 20% to 22%.
The nine units that have returned to commercial operation are Ohi-3 and -4, Genkai-3 and -4, Sendai-1 and -2, Takahama-3 and -4, and Ikata-3.