Fire alarms triggered nine times in four weeks at Japan's Fukushima Daiichi Nuclear Power Station

At 21:44 on September 3, a fire alarm was triggered in the water treatment control room building of Japan's Fukushima Daiichi Nuclear Power Station. Tokyo Electric Power Company (TEPCO) stated that no open flames or smoke were found at the scene. After firefighters arrived and conducted inspections, it was confirmed shortly after 22:30 that evening that this was not a fire. TEPCO said it would subsequently inspect the relevant detectors. Including this incident, the Fukushima Daiichi Nuclear Power Station has triggered a total of nine fire alarms in the past four weeks. Previously, on August 8, a fire alarm was triggered in the maintenance building for Units 5 and 6; on August 12, an alarm sounded in the emergency diesel generator room for the high-pressure core spray system of Unit 6; on August 13, an alarm sounded in the main office building; on August 15, an alarm sounded in the southwest stairwell area of the turbine building for Unit 5...

2026-09-04

Japan considers expanding reuse of decontaminated soil from Fukushima

Japan's Environment Minister Ishihara stated after a Cabinet meeting on September 1 that the government is considering and coordinating efforts to continue the decontaminated soil reuse project from Fukushima Prefecture at government offices and other locations in other regions, in order to raise public awareness of the relevant systems and safety management approaches. Following the Fukushima Daiichi Nuclear Power Station accident, large volumes of soil removed during decontamination operations in Fukushima Prefecture are currently stored at an interim storage facility within the prefecture. Under Japanese law, this soil must be finally disposed of outside the prefecture by March 2045. To reduce the volume of final disposal, the Japanese government is promoting the reuse of decontaminated soil with lower radiation levels. Late last month, construction work was carried out at national government joint office buildings in Sendai City and Saitama City, with soil for flower beds and other areas delivered to the sites. This marked the first time decontaminated soil was reused at such government facilities outside the Tokyo region.

2026-09-03

Japan Plans to Introduce Physical AI into Fukushima Daiichi Nuclear Power Station Decommissioning

The Japanese government and Tokyo Electric Power Company (TEPCO) are preparing to introduce Physical AI technology into the decommissioning operations at the Fukushima Daiichi Nuclear Power Station to enhance the autonomous operational capabilities of robots in high-radiation environments. This technology enables artificial intelligence to autonomously control robots based on on-site conditions, performing tasks such as inspection, data collection, and cleanup. To advance this effort, an advisory organization involving the government, businesses, universities, and research institutions is planned to be established within the year, with discussions centered on technology development, equipment application, and on-site verification. The organization is expected to be led by relevant government ministries and TEPCO, and will include AI startups, robot manufacturers, and university researchers.

2026-09-01

Fukushima Daiichi Nuclear Power Station begins 23rd discharge of treated nuclear-contaminated water

At 11:29 on August 31, Fukushima Daiichi Nuclear Power Station began its fifth discharge of treated nuclear-contaminated water in fiscal year 2026 and the 23rd overall. The operation is scheduled to last 19 days, concluding on September 18, with an estimated discharge of approximately 7,800 tonnes of nuclear-contaminated water diluted with seawater, equivalent to the capacity of about 8 storage tanks. The total tritium content is estimated at approximately 1.2 trillion becquerels. The reactors of Units 1 to 3 at Fukushima Daiichi still contain nuclear fuel that melted and solidified during the accident, known as fuel debris. Groundwater and rainwater that come into contact with this fuel debris form contaminated water. Since the discharge of treated nuclear-contaminated water began in August 2023, Fukushima Daiichi has cumulatively released approximately 173,000 tonnes, equivalent to about 173 storage tanks' capacity.

2026-09-01

Decontaminated soil from Fukushima used in flower beds at Saitama municipal government building

Decontaminated soil generated after the Fukushima Daiichi Nuclear Power Station accident was transported on August 30 to a government building in Saitama City, Japan, and used in a reuse project for on-site flower beds. The work took place at the Saitama Shintoshin Joint Government Building in Chuo Ward, Saitama City. Approximately one cubic meter of decontaminated soil was brought to the site, where workers dug holes in the flower beds, filled the soil to a depth of about 20 centimeters, and then covered it with approximately 20 centimeters of ordinary soil. Similar decontaminated soil reuse work was carried out on August 29 at the Sendai Joint Government Building in Miyagi Prefecture. Apart from demonstration projects within Fukushima Prefecture, this is the second reuse case conducted outside the Tokyo area. On the day of the work, approximately...

2026-08-31

Japan to Establish New Decontamination Base in Okuma, Fukushima

Japan's Ministry of the Environment has decided to establish a new work base in Okuma Town, Fukushima Prefecture, in the next fiscal year to coordinate decontamination and house demolition work in difficult-to-return zones following the accident at Tokyo Electric Power Company (TEPCO)'s Fukushima Daiichi Nuclear Power Station, aiming to accelerate environmental recovery in the affected areas. Within seven municipalities surrounding the Fukushima Daiichi Nuclear Power Station, approximately 309 square kilometers have been designated as difficult-to-return zones. These areas remain under strict control, with restrictions on residential habitation and entry, and evacuation orders remain in effect. Within the difficult-to-return zones, the Japanese government has established "specified return residential areas" and plans to advance decontamination, house demolition, and other measures based on residents' intentions to return. The proposed new base in Okuma Town will be responsible for on-site management and project coordination, with approximately 30 staff members expected to be assigned, and the relevant branch office currently located in Hirono Town will be relocated to Okuma Town.

2026-08-30

Hole of about 3 meters confirmed at bottom of reactor pressure vessel of Unit 3 at Fukushima Daiichi Nuclear Power Station

Tokyo Electric Power Company (TEPCO) announced on August 27 that a hole approximately 3 meters in diameter has been confirmed at the bottom of the reactor pressure vessel of Unit 3 at the Fukushima Daiichi Nuclear Power Station. The pressure vessel is a steel container that held nuclear fuel before the accident, with a cylindrical shape and a diameter of about 5.5 meters. This is the first time since the core meltdown accident at Units 1 to 3 of the Fukushima Daiichi Nuclear Power Station in 2011 that the specific size and shape of such a hole have been confirmed on the pressure vessel. The hole is believed to be related to the falling of melted nuclear fuel during the 2011 accident. After the accident, the containment vessel of Unit 3 has maintained a relatively high water level for an extended period, and access routes into the containment vessel are limited. TEPCO previously used a micro drone measuring approximately 12 centimeters per side...

2026-08-28

TEPCO replaces faulty motor of robotic arm at Fukushima Daiichi Unit 2

Tokyo Electric Power Company (TEPCO) began replacing the faulty motor of the robotic arm used for fuel debris retrieval trials at Unit 2 of the Fukushima Daiichi Nuclear Power Station on August 26. The robotic arm, approximately 22 meters long, is planned for use in the third fuel debris retrieval trial. During a previous operational inspection inside the reactor building of Unit 2, TEPCO found that the motor driving the robotic arm had malfunctioned, preventing the brake from releasing and the arm from extending. As the robotic arm is already installed on site, workers will enter the "front chamber" in front of the containment vessel to perform the replacement manually. The company stated that radiation levels in the work area will be strictly controlled to prevent workers from receiving excessive exposure. After this replacement, TEPCO will...

2026-08-27

Japan to Use Fukushima Decontaminated Soil at Government Office Buildings in Sendai and Saitama

At a Cabinet meeting held at the Prime Minister's Office on August 25, the Japanese government decided to use decontaminated soil generated from the Tokyo Electric Power Company (TEPCO) Fukushima Daiichi Nuclear Power Station accident for flower beds and other areas at joint government office buildings in Sendai City and Saitama City. This will mark the first use of such recycled soil outside Tokyo. According to the plan, the relevant office buildings will use a total of approximately 2 cubic meters of low-radioactivity "reconstruction recycled soil," with the specific construction schedule still being coordinated. The usage site in Saitama City is located at the government joint office building in the Saitama New Urban Center area, and Sendai City will also implement similar arrangements at its joint government office building. Under Japanese law, soil decontaminated after the Fukushima Daiichi Nuclear Power Station accident must be transported outside Fukushima Prefecture for final disposal by March 2045. The Japanese government hopes that by first using such soil in public facilities, it can promote the final disposal work outside Fukushima Prefecture and enhance public understanding of the safety and necessity of such soil.

2026-08-25

Three Years Since Japan Began Discharging Nuclear-Contaminated Water: Over 170,000 Tons Released Across 22 Rounds

Since August 24, 2023, Japan has been discharging nuclear-contaminated water from the Fukushima Daiichi Nuclear Power Station into the Pacific Ocean. As of August 24, 2026, Japan has completed a total of 22 rounds of discharge, with a cumulative volume of approximately 173,000 tons. It is understood that the volume of water stored in on-site tanks has decreased by about 7% compared to before the discharge began. Tokyo Electric Power Company plans to increase the discharge volume of nuclear-contaminated water starting from the current fiscal year and has set a target to complete the decommissioning of the nuclear power plant by 2051. ...

2026-08-24

Collective Radiation Dose of Workers at Japan's Fukushima Daiichi Nuclear Power Station Ranks Highest Nationwide

Japanese nuclear power plant operators are required to submit radiation management reports to the Nuclear Regulation Authority (NRA) annually, detailing the exposure status of plant workers. According to the relevant 2025 reports, the collective radiation dose of workers at Tokyo Electric Power Company (TEPCO)'s Fukushima Daiichi Nuclear Power Station remains significantly higher than at other Japanese nuclear plants, indicating that the radiological impact from post-accident on-site decommissioning and management work is still ongoing. By collective dose per plant, Fukushima Daiichi recorded 20.97 person-sieverts, the highest in Japan. This figure is nine times the 2.22 person-sieverts reported at Kansai Electric Power's Takahama Nuclear Power Station...

2026-08-24

Fire alarm triggered for sixth time in August at Japan's Fukushima Daiichi Nuclear Power Station; fire department confirms no fire occurred

At approximately 3:54 a.m. on August 21, a fire alarm was triggered on the first floor of the access control building at the Fukushima Daiichi Nuclear Power Station. Tokyo Electric Power Company (TEPCO) stated that no open flames or smoke were found near the site; shortly after 5:00 a.m., the fire department confirmed that the alarm was not caused by a fire. Readings from radiation monitoring stations around the plant also showed no significant fluctuations. This was the sixth fire alarm at the Fukushima Daiichi Nuclear Power Station since the beginning of August. Previously, the maintenance building for Units 5 and 6 triggered a fire alarm on August 8; the emergency diesel generator room for the high-pressure core spray system of Unit 6 triggered a fire alarm on August 12; the main administration building triggered a fire alarm on August 13...

2026-08-21

Trial lifting of damaged fuel assembly completed at Unit 2 of Japan's Fukushima Daiichi Nuclear Power Station

Tokyo Electric Power Company (TEPCO) announced on August 18 that a trial lifting of a damaged fuel assembly in the spent fuel pool of Unit 2 at the Fukushima Daiichi Nuclear Power Station has been completed. The assembly was damaged in a fall 45 years ago and was subsequently repaired with wire. This trial lifting was conducted to confirm whether it can be safely handled during the subsequent removal operation. A total of 615 fuel assemblies are stored in the Unit 2 fuel pool, including 587 spent fuel assemblies and 28 unused fuel assemblies. The removal work began on June 2, and the fuel assemblies will be transferred to the shared fuel pool within the plant site. As of August 17, 35 fuel assemblies had been removed. Despite interruptions during the operation, Tokyo Electric Power Company...

2026-08-20

Removal of Highly Radioactive Spent Fuel Begins at Unit 2 of Fukushima Daiichi Nuclear Power Station

Tokyo Electric Power Company Holdings (TEPCO) said on August 17 that it has begun removing spent fuel assemblies with high radiation levels from the spent fuel pool of Unit 2 at the Fukushima Daiichi Nuclear Power Station in northeastern Japan, the site of a severe nuclear accident. Last month, TEPCO removed 28 unused nuclear fuel assemblies from the Unit 2 spent fuel pool. Compared with spent fuel, these unused fuel assemblies pose relatively lower risks. The company plans to complete the removal of spent fuel from Unit 2 by the end of fiscal year 2028. To date, the Unit 2 spent fuel pool contains a total of 587 spent fuel assemblies, of which TEPCO has completed the removal of...

2026-08-18

Fire alarm triggered for fifth time at Fukushima Daiichi Nuclear Power Station in August; no fire confirmed on site

At 7:14 a.m. on August 18, a fire alarm was triggered on the first basement floor of the turbine building of Unit 5 at the Fukushima Daiichi Nuclear Power Station. Tokyo Electric Power Company (TEPCO) stated that after fire department personnel arrived and conducted inspections, no fire was confirmed on site at 7:55 a.m. Readings from radiation monitoring stations around the plant showed no significant fluctuations. This was the fifth time a fire alarm had been triggered at the Fukushima Daiichi Nuclear Power Station since the beginning of August. Previously, related alarms had occurred on August 8 at the maintenance building for Units 5 and 6, on August 12 at the emergency diesel generator room for the high-pressure core spray system of Unit 6, on August 13 at the main administration building, and on August 15 at the southwest stairwell of the turbine building of Unit 5. After each of the above alarms was triggered, the fire department confirmed that no fire had occurred...

2026-08-18

22nd Round of Fukushima Daiichi Nuclear Power Station ALPS Treated Water Discharge Completed

Tokyo Electric Power Company (TEPCO) stated on August 17 that the 22nd round of ALPS treated water discharge from the Fukushima Daiichi Nuclear Power Station had been completed by the afternoon of the same day (local time). This round of discharge began on July 30, with a total of 7,888 tonnes of ALPS treated water released. According to information released by TEPCO, the total amount of radioactive tritium contained in the water discharged in this round was approximately 1.3 trillion becquerels. This is the 4th round of ALPS treated water discharge from the Fukushima Daiichi Nuclear Power Station in Japan's fiscal year 2026. Japan began discharging ALPS treated water from the Fukushima Daiichi Nuclear Power Station in August 2023. To date, 22 rounds of discharge have been carried out, with a cumulative discharge volume of approximately 173,000 tonnes...

2026-08-18

New Decommissioning Plan for Fukushima Daiichi: Priority on Internal Investigation of Unit 3 Before Fuel Debris Retrieval

The Nuclear Damage Compensation and Decommissioning Facilitation Corporation of Japan released on August 6 an outline of the 2026 edition of the "Decommissioning Strategic Plan," proposing technical approaches for the decommissioning of Tokyo Electric Power Company's Fukushima Daiichi Nuclear Power Station. The plan highlights that, for the large-scale retrieval of melted fuel debris at Unit 3, expected to commence in or after fiscal year 2037, priority should currently be given to internal investigations of the reactor building to provide a more reliable basis for subsequent engineering plans. The plan states that the fuel debris retrieval method being studied by TEPCO still requires further improvement in certainty, with the key prerequisite being an understanding of the actual internal conditions of the reactor. Due to the high radiation levels of the water inside the unit following the accident...

2026-08-07

Nitrogen Supply Unit at Fukushima Daiichi Nuclear Power Station Resumes Operation After Malfunction

Tokyo Electric Power Company (TEPCO) reported on August 1 that a reactor nitrogen supply unit at the Fukushima Daiichi Nuclear Power Station malfunctioned that day, but was subsequently repaired and resumed gas supply. The company stated that during the malfunction, no significant fluctuations were observed in hydrogen concentrations inside the reactors of Units 1 to 3 or in surrounding radiation monitoring data, and no risk of hydrogen explosion was confirmed. The reactor containments and pressure vessels of Units 1 to 3 at the Fukushima Daiichi Nuclear Power Station require continuous nitrogen injection to suppress hydrogen accumulation resulting from radiolysis of water. If hydrogen concentrations exceed a certain level, the risk of hydrogen explosion may increase. According to TEPCO, at 11:14 a.m. on August 1, a worker...

2026-08-03

Japan's Fukushima Daiichi Nuclear Power Station launches 22nd release of radioactive wastewater into the ocean, approximately 7,800 tons this time

On the morning of July 30, 2026, Tokyo Electric Power Company (TEPCO) initiated a new round of nuclear-contaminated water discharge into the ocean at the Fukushima Daiichi Nuclear Power Station. This marks the 4th release within 2026 and the 22nd since the discharge plan began in August 2023. According to data released by TEPCO, this discharge is expected to continue until the 17th of next month, with a total volume of approximately 7,800 tons. The total amount of radioactive substance tritium contained therein is as high as approximately 1.3 trillion becquerels. Prior to this, Japan had conducted a total of 21 rounds of radioactive wastewater discharge by the 24th of this month, with a cumulative discharge volume reaching approximately 165,000 tons. This action continues to draw attention and concern from neighboring countries and the international community. This time...

2026-07-31

Third fuel debris retrieval test at Fukushima Daiichi Unit 2 postponed due to robotic arm malfunction

The robot used by Tokyo Electric Power Company (TEPCO) for the third experimental fuel debris retrieval at Fukushima Daiichi Nuclear Power Station Unit 2 malfunctioned during an on-site operational test, forcing the cancellation of the plan originally scheduled to start after July 2026 if all went well. The company stated it will reassess the relevant procedures. The malfunction occurred in part of the large robotic arm equipment used to collect fuel debris. During an operational test in the reactor building of Unit 2, TEPCO found an abnormality in one of the motors driving the robotic arm, causing the brake to fail to release and the arm to be unable to extend. The company is currently studying the replacement of the faulty motor. The third experimental retrieval plan was to use a large robotic arm...

2026-07-31

TEPCO says cooling interruption of spent fuel pool at Fukushima Daini Unit 1 due to human error

Tokyo Electric Power Company (TEPCO) announced on July 29 that the event in April 2026, where the spent fuel pool cooling system at Unit 1 of the Fukushima Daini Nuclear Power Plant was shut down for approximately 32 hours, was determined to be caused by human error. At the time of the incident, the plant was in the decommissioning phase. On April 5, a fault alarm was triggered by the cooling water circulation pump of Unit 1 at Fukushima Daini. After on-site personnel confirmed smoke from the equipment, the pump was stopped, resulting in an interruption of the spent fuel pool cooling system for about 32 hours. TEPCO previously stated that the cause was damage to the cable connecting the pump motor. According to TEPCO's latest explanation, the cable melting may be related to the installation method when the cable was replaced in 2012...

2026-07-30