Nuclear crucial to Japan meeting climate goals, says IEA

04 March 2021

Ten years after the March 2011 earthquake and subsequent accident at the Fukushima Daiichi plant resulted in significant disruption to its energy supply, Japan has made visible progress towards realising its vision of an efficient, resilient and sustainable energy system, the International Energy Agency (IEA) said today. However, it warned the country must act quickly if it is to achieve its ambition of reaching carbon neutrality by 2050. The restart of its idled nuclear power reactors will help it reach that goal, the IEA said.

Speaking at a webinar today for the launch of the Paris-based organisation's Energy Policy Review of Japan, IEA Executive Director Fatih Birol said: "The Japanese energy sector recovered from the damage in the right way ... despite the huge damage and large-scale loss of nuclear immediately after the Fukushima accident, Japan has avoided disruptions, such as major blackouts. It is a huge success story as a result of the Japanese government being nimble, moving very quickly, and finding different ways to get electricity."

Since 2011, Japan has embarked on major reforms of its energy market and diversified its energy mix, the IEA noted. Energy-related carbon dioxide emissions have fallen continuously since their peak in 2013, thanks to the expansion of renewable energy, the restart of some nuclear reactors and energy efficiency gains. By 2018, the country's CO2 emissions had declined to a level last seen in 2009. Reliance on fossil fuels has also declined but remains high at nearly 90% of energy supply. The carbon intensity of Japan's energy supply remains one of the highest among IEA members.

Last October, the new prime minister of Japan declared that the country aimed to reduce its greenhouse gas emissions to net zero by 2050. The government presented its new Green Growth Strategy in line with Carbon Neutrality in 2050 in December. The strategy identifies 14 sectors with high-growth potential towards the 2050 ambition. The next Strategic Energy Plan, which is under discussion, might include a revised 2030 energy mix. The government also recently announced plans to phase out inefficient coal plants by 2030.

In its report released today, the IEA analyses Japan's energy challenges and recommends possible solutions to help it achieve a secure, affordable and sustainable energy future. It highlights that Japan has seen continuous growth in renewables in the power sector, but that grid constraints have hampered investment in new projects and posed challenges to security of supply. The IEA said creating a well-integrated national grid and taking steps to improve the operational efficiency of the electricity system will facilitate the integration of more renewables while enhancing system resilience.

"The gradual restart of nuclear power generation, expansion of renewable energy and energy efficiency gains have reduced the need for imported fossil fuels, and contributed to a continuous decline in greenhouse gas emissions," the IEA says in the report.

"These reached a historic peak in 2013, as fossil fuels filled the gap caused by the temporary shutdown of all nuclear power plants after the Fukushima accident. In 2018, GHG emissions had decreased by 12% compared to 2013, back to the same level they had in 2009."

However, the report warns that achieving the aim of carbon neutrality by 2050 will require Japan to "substantially accelerate" the deployment of low-carbon technologies, address regulatory and institutional barriers, and further enhance competition in its energy markets. It will also be important to develop different decarbonisation scenarios, to prepare for the possibility that certain low-carbon technologies, such as nuclear, "do not expand as quickly as hoped."

The IEA makes a number of recommendations to the Japanese government in order to help the country smoothly manage the transformation of its energy sector. These include mapping out energy scenarios, including road maps, for achieving the 2050 decarbonisation aim that take into account various futures for the development of its energy sources. It should also establish price signals to encourage investment across the economy in efficient and low-carbon technologies.

The government should also encourage investment in the electricity network and improve electricity system operations to facilitate the cost-effective integration of larger shares of variable renewable electricity sources, achieve a diverse mix of low carbon electricity generation sources and enhance security of supply. In addition, it should advance electricity and gas market reform and consider making the Electricity and Gas Market Surveillance Commission a more independent regulator.

Nuclear's future role

Prior to the Fukushima accident, nuclear power was the largest carbon-free baseload source in Japan's electricity mix. At that time, 54 nuclear reactors, with 48.9 GWe capacity, supplied about 25% of the country's electricity. There were plans to increase the share of nuclear energy generation to 50% by 2030.

Japan's 5th Strategic Energy Plan of 2018 presented nuclear power as "an important base-load power source contributing to the stability of the long-term energy supply-and-demand structure". Under the plan, nuclear power is expected to achieve a 20-22% share of the country's electricity mix by 2030. According to the government, this goal is achievable once about 30 of the existing fleet of 33 remaining operable nuclear reactors return to service and have an average capacity factor of 80%.

Japan's reactors began restarting in 2015 with a production of 9.4 TWh, representing 0.9% of total electricity output. The IEA noted that, by May 2020, nine reactors had returned to operation. In 2019, nuclear power generated 63.8 TWh, representing 6.4% of the total power generation that year.

As of January this year, the reviews of 15 of the 33 operable reactors had been successfully completed. Of the remainder, 10 were in the Nuclear Regulation Authority (NRA) review process, and eight had not yet applied.

The IEA noted that, according to current regulations, the operating period of a power reactor is 40 years, with the possibility to extend this by 20 years. Japan's entire fleet of reactors will reach the end of their design life before 2050. If the 20-year additional plant licences were permitted for the entire current fleet, the last unit would be permanently shut down around 2070.


The report makes several recommendations specifically about nuclear power. It says the Japanese government should invest the necessary human and financial resources to accelerate the NRA's safety reviews of nuclear reactors. It should also undertake concerted efforts to promote the understanding of local communities and thereby accelerate the restart of nuclear power plants that have been confirmed as compatible with the NRA's safety regulations. The government should consider not deducting the extended period of time that reactors have remained offline whilst under NRA review for restart from their 40-year licences.

In order to speed up and rationalise decommissioning, the IEA says the government should regulate reactors slated for decommissioning separately from operating plants. It should also develop and implement a clear and streamlined plan for the management, interim storage and disposal of radioactive waste from plant decommissioning, in addition to fostering the development of a market-driven competitive decommissioning sector.

The government should also invest in attracting new talent to nuclear careers, thus ensuring the NRA's ability to perform all safety reviews in a timely and high-quality manner, as well as the long-term viability of the nuclear sector in Japan. Also, it should continue progress in the decommissioning of the Fukushima site, investment in the social and economic recovery of the Fukushima area, and the open exchange of information and lessons learned from the accident.

"I strongly believe that the policy and regulatory reforms proposed in this report can help Japan advance its energy and climate goals while supporting its economic growth," Birol says in the report's foreword. "As it has done since 1974, the IEA will continue to stand side-by-side with Japan as it moves ahead with the process of implementing the next round of its domestic energy and climate policies, as well as on the important work it is leading on global clean energy transitions."

Researched and written by World Nuclear News