Japan’s Energy Picture Fifteen Years Post-Fukushima 

March 2026 marks the fifteenth anniversary of the meltdown at the Fukushima Daiichi nuclear power plant, the largest nuclear disaster since the end of the Cold War. The disaster followed a catastrophic earthquake and tsunami, but its causes were complex. Blind spots in the plant’s design, poor maintenance and safety procedures, and lax government regulation all contributed to the plant’s collapse. More than a decade on, those human failures—more than the natural disasters—have contributed to lasting changes to the country’s nuclear industry and its energy mix. 

Prior to the 2011 disaster, nuclear reactors generated some 30 percent of Japan’s electricity. As of 2024, nuclear accounted for less than 10 percent—and even that low figure was the highest it had been in a decade. Though the government’s most recent energy strategy expanded its commitment to nuclear energy and its fleet of renewable energy sources is growing, natural gas has so far made up much of the gap that mothballed nuclear plants left in Japan’s energy supply.  

That solution has generated its own challenges, however. Virtually all of Japan’s natural gas is imported, the costs and geopolitical risks of which were laid bare after Russia’s full-scale invasion of Ukraine in 2022 and, more recently, the U.S. and Israeli attack on Iran. At the Indo-Pacific Energy Security Ministerial and Business Forum, held in Tokyo last weekend, Interior Secretary Doug Burgum and other representatives of the U.S. National Energy Dominance Council encouraged Japan to diversify its sourcing to include more American suppliers. That is a message Prime Minister Sanae Takaichi will no doubt hear again when she meets President Donald Trump for a summit later this month, but the United States itself has been an inconstant ally over the past year, leaving Takaichi few palatable options.  

Climate Realism Initiative Senior Fellows Daniel B. Poneman and Clara Gillispie explore the complicated legacy of the Fukushima disaster and what it means for the energy policy of Japan’s future.

Fukushima, Fifteen Years On 

Daniel B. Poneman is a senior fellow at the Council on Foreign Relations (CFR).

Last week marked the fifteenth anniversary of the Great East Japan Earthquake, popularly shorthanded to a single word: Fukushima. It is worth dwelling for a moment on the different descriptions, and their implications. 

The 2011 earthquake measured 9.0 to 9.1 on the moment magnitude scale, a more accurate measure than the Richter scale for powerful tremors. It was the fourth-strongest recorded earthquake by magnitude in world history, and the largest ever in recorded Japanese history.  

That may seem like a diversion from the shattering accident at the Fukushima Daiichi nuclear power plant. But it is not. Although more than nineteen thousand people tragically lost their lives from the earthquake and the massive tsunami, zero deaths resulted from radiation released during the acute stages of the crisis. In fact, the first—and to date, only—radiation fatality the Japanese government linked to the nuclear accident was a lung cancer death in 2018 suffered by a worker at the power plant.  

To be clear, one radiation death is one too many, and more Fukushima-related cancer deaths could yet be recorded. But the greatest adverse health effects caused by Fukushima to date resulted not from radiation but from fear. Fear drove a panicked evacuation at Fukushima, which may have caused needless distress, injuries, and fatalities. Fear—and politics—likewise drove Germany to abruptly abandon its own nuclear fleet and wage a major campaign to block other countries’ nuclear programs. Subsequently, scientists have concluded that Germany’s switch from clean nuclear to dirty coal power generation has killed around 1,100 Germans each year through complications from air pollution.   

Fifteen years on, the lessons of Fukushima continue to be widely studied and applied. At Fukushima, emergency backup generators were located in the plant’s basement and failed when they were flooded. Bureaucratic delay in deciding to vent Unit 1’s containment resulted in the accumulation of hydrogen and a subsequent explosion. Lessons [PDF] learned from those and other errors led to both engineering improvements at operating plants (including having portable equipment at plant sites to address unexpected events and reliance on passive safety systems that do not need electricity to cool reactors) and procedural reforms (such as granting onsite operators greater authority to act decisively in an emergency). Policymakers have learned from the disaster’s success stories, too; smart onsite actions by Naohiro Masuda, the site supervisor at Fukushima Daini, just ten kilometers away from the doomed Daiichi units, allowed that plant to shut down safely, as has been documented in a Harvard Business Review case study. 

Meanwhile, the world is once again turning to nuclear energy to address both burgeoning energy demand and the need to curb carbon emissions. China’s nuclear fleet is surging and on track to surpass U.S. capacity as soon as 2030. Just last week at the Paris Nuclear Summit, four more countries pledged to triple their installed nuclear capacity by 2050, bringing that number to thirty-eight governments worldwide. In the United States, the Trump administration has issued four executive orders aimed at restoring U.S. nuclear leadership, including a goal of quadrupling the domestic-installed nuclear fleet by the same year. 

In Japan, post-Ukraine concern over security and climate, combined with extraordinary attention to safety reforms in response to Fukushima, led the Ministry of Economy, Trade and Industry, in its 2025 energy plan, to reverse earlier policy and seek to maximize nuclear energy to meet growing demand. This week’s visit by Takaichi will provide a golden opportunity for the U.S. and Japanese governments to join forces in investments to restore their mutual leadership in an industry where China and Russia have been gaining strategic and economic advantage, at American and Japanese expense. 

Success is far from guaranteed. Although countries around the world are increasingly turning to nuclear energy, fear of atomic fission persists in many quarters. Policymakers have worked to repair the social license supporting widespread nuclear deployment through education and vigilant work on nuclear safety, but that license remains fragile. Another nuclear accident, anywhere in the world, could set back the nuclear industry once again. That is why nuclear engineers and regulators worldwide need to continue to draw from the lessons of Fukushima, to focus on safety culture, and to leverage the tools of modern technology to create ever-safer reactors and ever-smarter operators. If nuclear energy successfully expands, the benefits from tapping abundant clean energy will improve billions of lives worldwide. If it fails, this precious planet and all who live here will suffer.

Beyond Nuclear: What the Great East Japan Earthquake Meant for Japan’s Energy Security 

Clara Gillispie is senior fellow for climate and energy at the Council on Foreign Relations (CFR).

In the period immediately following the Great East Japan Earthquake, Japan faced its most significant energy crisis since the oil shocks of the 1970s. The earthquake itself damaged a wide spectrum of critical energy infrastructure in northeastern Japan, including oil- and coal-fired power plants and multiple refineries. Yet it was the nuclear disaster at Fukushima Daiichi, more than any other energy infrastructure damage, that would reveal fundamental weaknesses and gaps in Japan’s approach to energy policy-making.  

Less than one year prior to the earthquake, Japan had adopted a major overhaul of its long-term energy development plan, with an expressed aim of better guaranteeing a secure, reliable supply of energy for the country. By and large, it framed this concern as primarily about Japan’s total dependence on imports to meet its demands for oil, natural gas, and coal—and, by extension, the country’s high degree of exposure to global market shocks. That this plan would ultimately emphasize the benefits of a prominent and growing role for nuclear energy in the country’s power generation mix was, thus, hardly surprising. But it quite literally offered no “plan B”—a vision for what (if anything) Japan could do if nuclear energy played anything other than a maximal role in meeting the country’s rising demands for electricity.  

That weakness became more than hypothetical with the shutdown of all fifty-four of the country’s nuclear reactors following the Fukushima Daiichi disaster. Virtually overnight, Japan lost one-third of its power supply. Oil- and coal-fired power plants that had been idled or otherwise slated for retirement were suddenly asked to reverse course and boost their overall generation output to help close the gap. Japan’s demand for energy imports, thus, suddenly skyrocketed—and as importers scrambled to find enough new, last-minute supply in tight global markets, they found themselves also paying a premium; consequentially, Japan’s energy import bills surged even more sharply. Japan struggled to fully close its power generation gap and went through a period of rolling blackouts. All of this is to say nothing about what the pivot from nuclear to fossil fuels meant for the environment, as a sudden rise in carbon dioxide (CO₂) emissions undercut air quality in multiple parts of the country. Though those challenges were most acute in the weeks and months that followed the earthquake, they would remain a constant strain on Japan’s systems for years.    

Suddenly, not only was Japan off track with the roadmap in its basic energy plan, but the very idea that it could rely on nuclear energy as the primary answer to its ongoing energy supply insecurities was suddenly also in doubt. The 2010 plan was, as a result, almost immediately scrapped. But the debate about what should replace it would stretch on for years, and even then, subsequent strategies and roadmaps have continued to come to wildly different conclusions about what the “right” energy mix looks like.  

In the years since 2011, Japan’s energy security outlook has improved. The government’s aggressive promotion of energy conservation efforts, for example, substantially reduced otherwise projected growth in demand for electricity. Public financial incentives, as well as larger market reforms, also supported scaling up new and important solar energy capacity, a source that, prior to the crisis, had played virtually no role in the country’s power generation mix. Combined, both actions helped to raise Japan’s energy self-sufficiency and offset what would otherwise have been an even more painful spike in the country’s energy import bills.  

Yet none of that meant that ensuring Japan had reliable, affordable access to sufficient supplies of oil, natural gas, and coal was suddenly less essential to the country’s long-term economic health. Nor did it mean that Japan could ignore the real consequences that its reliance on fossil fuels was having on the environment. In turn, Japan also took meaningful, significant steps to prioritize a role for natural gas over other fuels, a strategy that envisioned both the imperative of reducing total demand for oil and coal and the opportunity of a rapidly expanding menu of potential natural gas suppliers as a way to mitigate (if not eliminate) its exposure to supply shocks in any one region. 

Fifteen years after Fukushima, multiple uncertainties still characterize Japan’s energy future. As of March 2026, the restart of Japan’s nuclear reactors is ongoing and shows signs of picking up steam, but it has also continued to be hampered by periodic delays and setbacks. More broadly, both Japanese officials and experts have regularly emphasized that the best energy security strategy for Japan is not just about any one fuel or technology so much as it is about how nimbly the country can adapt to changing energy market realities. Japan’s latest strategic energy plan—adopted in 2025—even explicitly acknowledges the need for flexibility. It outlines Tokyo’s plan for a scenario in which nuclear and renewables combined play a maximal role in Japan’s power generation mix—and a second scenario in which they do not.  

That latter scenario anticipates that, to make up any shortfall, natural gas would inevitably play a prominent and even greater role in the country’s power generation mix. Policymakers were, of course, still deeply aware of not just the benefits, but also the risks of such an approach, making the need for an explicit strategy for how Japan might navigate a less-than-certain future all the more vital. Although it could be tempting to view those two scenarios as different futures that Japan can pursue, or easily pivot between, amid rapidly changing global energy markets, the Great East Japan Earthquake underscored the extent to which it is not so simple.