I had been to Japan once before, in 2015, and I am grateful to Washington Policy and Analysis and their Santa Fe Leadership Program for giving me the opportunity to visit again and engage with high-level decision-makers across the Japanese government and nuclear industry.

Before the Fukushima Daiichi accident, Japan had the third-largest fleet of operating nuclear power reactors (behind the U.S. and France). The country was also one of the largest investors in nuclear research and development, with reputable programs for fast breeder reactors and fuel recycling. As the only country to have nuclear weapons used against it, Japan has maintained a strong opposition to nuclear weapons and proliferation. Notably, Japan was the largest producer of nuclear energy that does not possess nuclear weapons. 

The first thing that struck me upon this visit to Japan was the lack of air conditioning. The country had just emerged from the hottest June on record, which led to severe power shortages. The use of air conditioning was limited, lights were dimmed, and electric billboards across the country urged residents to conserve energy. When meeting with government agencies, the intercom would frequently announce a short period of energy conservation and encourage staff to turn off unused lights and equipment.

Combined with aggressive Covid precautions, including almost universal (but voluntary!) masking outdoors, this serious energy conservation left a strong impression that Japan was facing several intersecting crises.

Government meetings 

Over the course of the week, we met with representatives from several government agencies, including the Ministry of Foreign Affairs and the Ministry of Education, Culture, Sports, Science, and Technology. But the conversation with representatives from the Ministry of Economy, Trade, and Industry — similar to the Department of Energy in the U.S. — resonated with me the most. 

I’m from California, and we have our own share of energy challenges. But those that Japan faces are even more difficult. For one, Japan is an island and has to import most of its energy — liquefied natural gas, or LNG, for the power sector and oil for transportation — from the Middle East. It has been hit hard by the surges in LNG prices and potential gas shortages amid the Russian invasion of Ukraine.

Even if it could buy LNG, Japan faces a shortfall of power plant capacity after the semi-temporary shut-down of most of its nuclear fleet in 2011. While California typically operates with a 15-20% reserve margin in the critical summer months — meaning they have unused power plants waiting in the wings –Tokyo often operated with just a 1% margin this summer.  

Japan has about 90% of the land area of California but a population more than three times greater. The country is motivated to develop renewables and wean itselfoff imported LNG, and the government has set supportive policies to speed deployment. But it has a limited ability to site and build wind and solar projects: Almost 70% of Japan’s land area is forest and mountains, which is about twice as much as Germany’s. There is strong opposition to building in these landscapes. Building on slopes can also be technically challenging (and costly). For example, utility-scale solar farms that do get built on hillsides have occasionally caused landslides. Similar to California, the potential for offshore wind in Japan is limited. 

What Japan does have that California does not is a fleet of large-scale, low-carbon nuclear power plants waiting to be restarted upon final safety evaluations. At the time of my visit, out of 60 reactors operating pre-2011, 10 units had been restarted, with another 7 having passed their safety review. Another 10 units were still under review, and nine still need to apply. After my visit, Japan announced plans to accelerate restarts in anticipation of power shortfalls this winter. Similar to the U.S., the government has also expressed interest in extending the operational lifetime of reactors to help achieve clean energy targets in the long term. And unlike the U.S., Japan has a clear, national plan for handling its spent nuclear fuel.

Rokkasho Nuclear Fuel Reprocessing Facility

When we talk about recycling or reprocessing nuclear fuels, you almost always hear references to France and its reprocessing plant at La Hague (processing 1,700 tonnes of fuel annually). I knew Japan had plans to reprocess fuel but had the image that it was far in the future, only in the R&D stages now. However, a visit to the under-construction reprocessing facility at Rokkasho clarified two things very clear about recycling spent nuclear fuel in Japan: It is 1) very real, and 2) very challenging.

When I visited in July, the reprocessing plant was nearly complete, with an expected start-up of late 2022. But this sense of completion belies a troubling history. Construction began in 1993, with an expected start-up just four years later. However, the project has announced delays 20 times since construction started, primarily due to changing regulatory requirements. If the project succeeds in starting this winter, it will be more than 20 years overdue.

Japan currently has 19,000 tonnes of spent fuel at power plant sites across the country, with 3,000 tonnes sitting in a storage pool at Rokkasho. Once the reprocessing plant is operating at its maximum throughput of 800 tonnes per year, it will take close to four years to reprocess just what the country has stored on-site and more than 20 years to reprocess the spent fuel that now exists across Japan.

Japan also has a much smaller operating nuclear fleet today than it did when Rokkasho was designed, meaning it has much less demand for the mixed-oxide fuel that will be produced at Rokkasho. This is a problem because Japan faces limits on how much separated plutonium it can store on-site as a non-nuclear weapons state under the international Nuclear Non-Proliferation Treaty. 


When I visited the Fukushima Daiichi site in 2015, my overarching impression was that very little had been done since the accident in 2011. That was, of course, not true, but the site was still operating in an emergency response phase, addressing problems as they popped up. On this visit, however, I got the impression that decommissioning was close to finished. The ice wall that blocks groundwater from seeping into the damaged reactors has been completed, although now the decommissioning team is struggling with maintenance and performance. The water treatment plant, called ALPS, which removes radioactive material from stored water before it is released into the ocean, has been completed. The main unresolved problem is removing melted fuel from the floor of the failure reactors, but specialists are working to use robots to remove the fuel.

Radiation levels around the site are very low. We could walk up to within 100 meters of the damaged reactors without any protective gear. We were, of course, wearing face masks for protection against Covid-19. There are digital displays of the air dose radiation level all over the site. Upon entering from the main road, air dose rates were 0.2 micro-Sieverts per hour (µSv/hr), which is about twice the natural background radiation in London. All visitors are required to wear dosimeters to measure their total radiation exposure, and mine registered 0.03 mili-Sieverts, far less than I received on my flight to Japan (from naturally-occurring cosmic radiation).

Touring Fukushima today, it is impressive how much Japan has recovered from the accident and amazing how many resources have gone into the cleanup and decommissioning. Seeing the thousands of workers moving through the Fukushima site daily, it can be perplexing that the Japanese government still supports nuclear energy and is looking to accelerate restarts of remaining operable reactors. But for a large, urban country like Japan that worries about its industrial economy, wants to reduce greenhouse gas emissions, and prioritizes preserving its natural landscapes, there isn’t another good option for producing electricity.