Reactor reboot at world's largest nuclear plant highlights flaws in Japan's radioactive waste plans

KASHIWAZAKI, Japan (AP) — Japan has resumed operations at the world’s largest nuclear power plant to help the country meet huge electricity demands during a global oil crisis, but the reboot highlights a big problem: Japan is running out of space for spent nuclear fuel and has no viable plans for permanent disposal of the radioactive waste.

The restart of No. 6 reactor at Kashiwazaki-Kariwa Nuclear Power Station earlier this year was meant to spur a movement to bring more nuclear reactors online. Kashiwazaki-Kariwa is one of three plants whose cooling pools will be full in five years, according to the Federation of Electric Power Companies of Japan.

“Without solid (fuel management) plans, our power generation will stall sooner or later,” Kashiwazaki-Kariwa General Manager Takeyuki Inagaki said.

After decades of seeking permanent storage for highly radioactive spent fuel, the government is considering Minamitorishima, a remote Pacific island south of Tokyo. But the selection has faced skepticism and criticism stemming from Japan's arbitrary actions on spent fuel and radioactive waste management.

Only 15 of Japan’s 54 reactors have restarted since the March 2011 Fukushima disaster, when a 9.0 earthquake off Japan’s northeastern coast and a subsequent tsunami caused meltdowns at three reactors operated by Tokyo Electric Power Company Holdings, or TEPCO. About 160,000 people fled from Fukushima and some areas remain unlivable.

Kashiazaki-Kariwa, also run by TEPCO, was shut down after the Fukushima disaster as part of a nationwide nuclear power stoppage.

The spent fuel in a cooling pool at Kashiwazaki-Kariwa No. 6 reactor, which is 88% filled, can be seen from a top-floor observation area. TEPCO has installed filtered venting systems and devices to prevent hydrogen explosions among additional safety measures based on lessons from Fukushima.

Prime Minister Sanae Takaichi is pushing to bring more nuclear plants online, resulting in more spent fuel. Without a viable permanent storage plan, there are worries that reactors will have to close when storage space runs out.

There are two options for dealing with spent nuclear fuel: direct disposal as waste or recycling to extract plutonium and uranium for reuse.

Japan insists on recycling, saying it will help the resource-poor nation's energy needs while reducing the toxicity and volume of radioactive waste. But a reactor designed for plutonium reuse, a key part of the recycling, has failed. Reprocessing also won’t be able to handle all the spent fuel, adding to a plutonium stockpile that already is large enough to arm thousands of atomic bombs.

Experts say Japan should also consider the direct disposal option.

As of December 2025, cooling pools at 17 Japanese nuclear power plants held more than 17,000 tons (15,422 metric tons) of spent fuel, using nearly 80% of total storage capacity, according to the Ministry of Economy, Trade and Industry.

Beyond the large amount of radioactive waste from normal reactors, Japan also “has to deal with massive and largely unknown high-level nuclear waste from the Fukushima disaster,” said Lila Okamura, a Senshu University professor and expert on environmental politics and nuclear waste management.

Choosing a final disposal site for spent fuel and building a facility would require 100 years and tens of thousands of years to monitor the storage deep underground. For a generations-long project, Japan should plan carefully and not rush the current plan that is full of uncertainties, Okamura said.

Weeks after Kashiwazaki-Kariwa's No. 6 reactor came back online for the first time in 14 years since the Fukushima disaster, Industry Minister Ryosei Akazawa approached Ogasawara village to request a feasibility study for a high-level radioactive waste site on Minamitorishima, an island administered by Ogasawara, which is part of Tokyo.

“With a lot of spent fuel accumulating at nuclear power plants across the country, a final disposal of radioactive waste is a crucial challenge that must be resolved,” Akazawa said in a letter to Ogasawara Mayor Masaaki Shibuya.

The government-owned Minamitorishima, about 2,000 kilometers (1,242 miles) south of Tokyo, has no permanent residents. The Japanese army is constructing a firing range for long-range, surface-to-ship missiles as a deterrent to China. The island also has deep sea deposits rich with rare earth minerals.

“The move seems political,” said Satoshi Takano, a member of a government panel looking at final disposal of spent fuel. “There will be little opposition from a government-owned remote island.”

Some experts say the island, which sits on a geologically stable tectonic plate, could be suitable. Many residents on Ogasawara and two nearby islands raised concerns about safety and tourism.

“I was baffled when I heard about the plan,” Ogasawara assembly member Yusuke Hirano told an assembly meeting. “I think nuclear waste is incompatible with islands that are a UNESCO Natural World Heritage site.”

Finding a community willing to host a highly radioactive dump site has been difficult, even with a raft of financial enticements. Minamitorishima is the fourth location to have a feasibility study since the government started looking in the early 2000s.

The whole review process will take about two decades. Municipalities participating in the first stage can receive up to 2 billion yen ($12.8 million) in government subsidies. The next stage would bring up to 7 billion yen ($44.7 million). Funding details for a final study haven't been disclosed.

The world’s first final disposal site for spent nuclear fuel is set to open in Finland later this year. Britain, Germany and the United States have abandoned reprocessing largely because of high costs and technical challenges, while several other countries are discussing plans for direct disposal sites.

Inagaki, the Kashiwazaki-Kariwa general manager, said TEPCO is transferring spent fuel from No. 6 reactor to other reactors at the plant with more space, but the utility hopes to resume shipments to a dry cask storage in northern Japan as a near-term solution. Other utilities with nearly full pools have announced plans to build dry-cask storage at their plants.

Many residents worry about Japan's growing stockpile because high-density storage of spent fuel could also increase overheating risks.

Mie Kuwabara, a civil activist in Niigata, wondered “where will it go next?”

“It's irresponsible to accelerate restarts and produce more spent fuel without deciding its final destination,” said Kuwabara, who also is skeptical about using Minamitorishima.

“It's like saying that it's OK to put a facility there because nobody is around to complain if there is a problem,” Kuwabara said. “It's scary.”

Temporary high-level radioactive waste storage area is seen at Japan Nuclear Fuel Limited in Rokkasho, Aomori, northern Japan, in July 2023. (Kyodo News via AP)

A cask containing spent fuel from Kashiwazaki-Kariwa is transported to an interim storage in Mutsu, Aomori, northern Japan on Sept. 26, 2024. (Kyodo News via AP)

FILE - The Unit 6 reactor building is pictured during a media tour at Tokyo Electric Power Company Holdings' (TEPCO) Kashiwazaki-Kariwa nuclear power station in Kariwa Village, Niigata prefecture, Japan on Friday, May 1, 2026. (Toru Hanai/Pool Photo via AP, File)

This aerial photo shows Minamitorishima, an island administered by Ogasawara village, which is part of Tokyo on Nov. 21, 2012. (Japan Pool/Kyodo News via AP)

FILE - The operation floor inside the Unit 6 reactor building is pictured during a media tour at Tokyo Electric Power Company Holdings' (TEPCO) Kashiwazaki-Kariwa nuclear power station in Kariwa Village, Niigata prefecture, Japan on Friday, May 1, 2026. (Toru Hanai/Pool Photo via AP, File)

President Donald Trump's planned UFC fight on the White House's South Lawn has required a monumental effort from more than seven federal agencies, hundreds of staff working onsite daily and at least $60 million, according to a legal filing that offers a glimpse into the preparations.

The event is part of the 250th anniversary of America’s founding, and is scheduled for the weekend with the main attraction — seven mixed martial arts matches — on Sunday.

That is, if a judge doesn't halt the proceedings, which is sought by two Virginia residents in a federal lawsuit against the National Park Service, which oversees the South Lawn.

The agency filed a rebuff of the request Tuesday in court, and, in it, laid out the operations for the event.

“Well over $60 million and tens of thousands of hours of labor have been expended,” the document read, adding that the money came from the UFC and groups affiliated with it.

It's the eight-sided cage that surrounds the sometimes bloodied combatants and sits at the center of the constructed arena on the South Lawn.

The arena is expected to hold 4,000 spectators, with another 120,000 visitors — who swung tickets from an online lottery — anticipated to watch from the nearby Ellipse.

The installation began May 20, and the Secret Service worked with the UFC to screen between 20 and 30 trucks of equipment — as well as between “700 and 900” staff — that came in daily for the installation.

The document did not specify the extent of government resources spent on the project, but said seven agencies, including Homeland Security and the Federal Aviation Administration, have “allocated significant resources and manpower."

It’ll kick off Saturday with a ceremonial weigh-in at the Ellipse, followed by a concert by country musicians The Zac Brown Band.

A UFC Freedom 250 Fan Fest will be ongoing through the weekend, with “interactive experiences,” live shows, celebrity appearances, “exclusive on-stage moments,” meet and greets, live music and interviews with the athletes.

Sunday night is when the seven bouts kick off. At the close, Trump is scheduled to fly to France for the G7 summit.

Disassembly of the installations will begin the next day, and they are expected to be entirely removed by June 23.

There are 14 athletes competing, and their training is rigorous.

Preparations start months in advance, working toward more intense weight cutting and diet alteration in the final week that can include fasting, extreme sauna use and hot Epsom salt baths.

They could be shaving as many as 20 pounds before weigh-ins, which are designed to keep the competition fair between similarly weighted combatants.

It was filed Saturday by the Public Integrity Project on behalf of the two Virginia residents and argues that Trump’s authorization of the event violated National Park Service regulations prohibiting sporting events on federal parklands.

One of the attorneys, Brendan Ballou, characterized it as a “corrupt use of our most sacred national monuments for private gain."

The National Park Service pushed back on that claim, but also detailed the event's preparations to make a point.

“All these hopes could be dashed at the very last moment," it read, "by the whim of two people who believe they have superior taste and want to spoil the event for everyone else.”

Workers continue building the cage for a future UFC fight on the South Lawn in front of the White House, Friday, June 5, 2026, in Washington. (AP Photo/Allison Robbert)

Workers continue building the stage for a future UFC fight on the South Lawn of the White House in Washington, Tuesday, June 9, 2026. (AP Photo/Cliff Owen)