Fukushima ALPS-Treated Water Discharge

Since 2021, at the request of the Government of Japan, the Agency has been independently reviewing the safety of discharging advanced liquid processing system (ALPS) treated water from the Fukushima Daiichi Nuclear Power Station into the sea. The Agency has committed to assessing and monitoring activities before, during and after the discharge, ensuring consistency with international safety standards.

In 2024, the Agency maintained its pivotal role in overseeing the discharge process, which began in August 2023. Since the beginning of the discharge, 10 batches totalling 78 300 cubic metres of ALPS-treated water have been discharged, with independent Agency analyses confirming tritium levels well below the regulatory and operational limits.

The Agency’s dedicated Task Force, comprising independent and internationally recognized experts from around the world and Agency experts, has conducted three missions since the commencement of the discharge, including reviews in April and December 2024 to assess its technical, regulatory and operational aspects. The Agency also performed interlaboratory comparisons and on-site measurements in 2024 to verify environmental radionuclide concentrations and radionuclide concentrations in ALPS-treated water and to monitor the radiation exposure of workers, which confirmed consistency with international safety standards.

In response to requests from Japan and concerns expressed by Member States, the Agency introduced additional measures to promote transparency, expand international participation and build trust in the region during the ongoing release of ALPS-treated water. These additional measures allow for hands-on independent sampling and monitoring to ensure that the discharges of ALPS-treated water remain within defined limits and are conducted within agreed parameters set by the Agency in its role as an independent, impartial and technical organization.

Since 2023, the Agency has maintained a continuous presence at the Fukushima site through its dedicated office and its laboratory. This on-site Agency laboratory in Fukushima is being upgraded with new equipment in order to analyse a broader range of radionuclides and achieve greater sensitivity in water and environmental sample testing, and the Agency continues to assess that Japan’s ALPS-treated water discharge remains safe, transparent and scientifically validated.