New PM, restarts, ongoing cleanup on 15th anniversary of Fukushima accident

Takaichi

A pronuclear PM: Japanese Prime Minister Sanae Takaichi's support for nuclear energy has been apparent before and after she became prime minister in October. Takaichi is both the first woman to hold this position and the first woman to head the Liberal Democratic Party.

In her policy speech to the Japanese Parliament in February, she mentioned nuclear energy multiple times. She supports the public and private sectors working together to accelerate the restart of nuclear plants deemed safe by the country's Nuclear Regulation Authority. She also supports the development of advanced reactors in the country and has proposed placing these reactors on the sites of decommissioned nuclear plants. Takaichi also voiced her support to "bring about the early societal application of fusion energy, ahead of the rest of the world."

Shortly after her appointment in the fall, Takaichi and President Donald Trump met to announce that Japan would provide up to $332 billion in support of energy projects in the United States, including nuclear energy infrastructure, stemming from a U.S.-Japan framework agreement signed the previous July when Japan committed to investing $550 billion in U.S. industries.

Among the items discussed were the following:

• Up to $100 billion to support Westinghouse in the construction of AP1000 large-scale reactors and small modular reactors, with possible partnerships with Mitsubishi Heavy Industries, Toshiba Group, and IHI Corp.
• Up to $100 billion to support the construction of SMRs such as the BWRX-300, which GE Vernova Hitachi is building at the Darlington nuclear power plant in Ontario, Canada.

Reuters reported that the two countries are looking to add another nuclear power project in a second round of deals that could be announced when the two leaders meet in Washington, D.C., later this month.

But it isn't just Takaichi who is in staunch support of nuclear energy. Reuters also reported Yuichiro Tamaki, the leader of the opposition Democratic Party for the People, wrote on the social media platform X on Monday that Japan needs to use its nuclear plants and make "full use ⁠of nuclear power as a carbon-free power source with less dependence on overseas sources" in order to overcome rising energy bills due to the Iranian conflict.

Restarting the reactors: The 2011 Fukushima accident prompted the shutdown of all of Japan's nuclear reactors, which numbered 54 at the time. Prior to 2026, only 14 out of 33 operable reactors had restarted.

In January, TEPCO began to restart Unit 6 at Kashiwazaki Kariwa nuclear power plant in Japan's Niigata Prefecture. This restart is significant given it is the first for TEPCO, which operated Fukushima Daiichi. Furthermore, Kashiwazaki Kariwa's seven reactors have a combined capacity of nearly 8 GW, making it one of the world's largest nuclear plants.

The original restart, however, lasted only a few hours before it was suspended after an alarm sounded during reactor startup procedures. During the investigation that followed, it was determined there was no danger inside or outside the plant. The restart resumed on February 9, with reports that commercial operation is scheduled to commence on March 18.

TEPCO plans to restart Kashiwazaki Kariwa's Unit 7 by 2030.

Restarting Japan's fleet of nuclear reactors is a key cog in the country's ambitious plans of carbon neutrality by 2050.

Cleanup and decommissioning: Work continues on the decommissioning of the six reactors of Fukushima Daiichi, a process that TEPCO has said will take 30-40 years to complete. The process hit a major milestone in January, when workers completed the installation of a retractable roof over Unit 1. According to TEPCO, "An overhead crane will be installed in preparation for full-scale rubble removal, and we will continue with the installation of ancillary equipment, such as dust monitors and ventilation equipment."

"We will continue to prioritize safety while we move forward with this task with the intention of commencing fuel removal from Unit 1 between [fiscal year] 2027 and FY2028," TEPCO said in a January update.

Over at Unit 2, fuel handling equipment is being installed with plans to commence fuel removal during FY 2026. Tests have been underway since December 12, 2025.

The complex cleanup at Fukushima Daiichi has required the use of robots and drones. In October, TEPCO used small submersible cleaning robots to clean the bottom of the Unit 2 cask pit. In November, TEPCO used a remotely operated submersible vehicle to remove pieces of sheetlike debris that may hinder fuel removal. And in February, TEPCO announced plans to use micro drones as small as a human hand to conduct an internal investigation of the nonsubmerged areas of the Unit 3 primary containment vessel (PCV).

Also in February, TEPCO unveiled a 72-foot-long robotic arm that will be used to retrieve fuel debris from inside the reactors. Multiple tools for things like cutting and 3D modeling can be attached to the tip of the arm, depending on the task. The plan is to begin PCV internal investigations and debris sampling this summer.

Amid the cleanup process is the ongoing release of Advanced Liquid Processing System (ALPS)-treated wastewater from Fukushima to the Pacific Ocean. This water is blended with seawater prior to being discharged via a 1-kilometer tunnel into the Pacific.

Since Japan began releasing ALPS-treated water in August 2023, roughly 133,000 cubic meters of ALPS wastewater have been discharged into the ocean.

During the latest release in March, the International Atomic Energy Agency confirmed that the tritium levels were far below the operational limits set by Japan. In fact, all 18 wastewater discharges have reported tritium levels far below the operational limits.