Country profile: Japan

Summary figures for 2017

The following information is from the NEA publication Nuclear Energy Data, the annual compilation of official statistics and country reports on nuclear energy in OECD member countries.

Country Number of nuclear power plants connected to the grid Nuclear electricity generation (net TWh) Nuclear percentage of total electricity supply
Japan 40 29.3 * 2.7
OECD Pacific64170.69.0
OECD Total3111 856.817.6
NEA Total3522 062.617.9
* Secretariat estimate; N/A Not available.

Country report

The Japanese electricity market was deregulated in April 2016 at the distribution level, and the Revised Electricity Business Act 2015 requires legal separation of generation from transmission and distribution by April 2020. As the first step towards market reform, the Organization for Cross-Regional Coordination of Transmission Operators was set up in April 2015 to assess generation adequacy and to ensure that adequate transmission capacity is available. Before liberalisation, in September 2015, the Electricity Market Surveillance Commission (EMSC) was established as the regulatory authority for electricity under the Ministry of Economy, Trade and Industry (METI).

The Strategic Energy Plan of Japan was revised in July 2018 and stated that "On the premise that safety comes before everything else and that every possible effort is made to resolve the people's concerns, judgement as to whether nuclear power plants meet the new regulatory requirements will be left to the Nuclear Regulation Authority (NRA) and in case that the NRA confirms the conformity of nuclear power plants with the new regulatory requirements, which are of the most stringent level in the world, the Japanese government will follow the NRA's judgement and will proceed with the restart of the nuclear power plants." Additionally, the plan also strengthens measures for the steady realisation of the 2030 energy mix set in 2015, which calls for nuclear energy to account for 20-22% of power generation in 2030. Actually, this energy mix is consistent with the reduction target submitted as nationally determined contribution (NDC) for COP21 to reduce GHG emissions by 26% from 2013 to 2030 (as of July 2018).

In accordance with the principles set up in the Strategic Energy Plan, four nuclear reactors are in operation as of December 2017. Two nuclear reactors, Sendai 1 and Sendai 2, were restarted in August and October 2015, respectively, for the first time since the new regulation had taken effect after the Fukushima Daiichi nuclear accident. These were followed by Takahama 3 and Takahama 4 in January and February 2016, respectively. In March 2016, a district court injunction then forced the operator to shut down the Takahama units, but in March 2017 the Osaka High Court revoked the decision and the reactors were restarted in June and May 2017, respectively. Ikata 3 nuclear reactor was restarted in August 2016, but in December 2017, the Hiroshima High Court ordered the reactor to be temporarily shut down until September 2018 (Hiroshima High Court revoked the order in September 2018). In addition, the NRA granted permission for changes in reactor installation of Genkai 3 and Genkai 4 in January 2017 and of Ohi 3 and Ohi 4 in May 2017.

Japan is also taking all necessary measures and promoting related research and development to ensure nuclear non-proliferation and strengthen nuclear security in light of international developments.

The Japanese government is taking thorough measures to minimise the risk of accidents, considering the experience and lessons learnt from the Tokyo Electric Power Company's (TEPCO's) Fukushima Daiichi nuclear accident.

As a first step towards realising the final disposal of high-level radioactive waste, in July 2017 the Japanese government published the "Nationwide Map of Scientific Features". The map shows Japan's scientific features (e.g. volcanic activity, faulting and mineral resources), which are necessary to consider in order to identify regions suitable for geological disposal of high-level radioactive waste.

Source: Nuclear Energy Data 2018