IAEA Conducts New Independent Water Sampling at Fukushima Plant

The IAEA introduced the Additional Measures programme in October 2024 to expand international involvement in monitoring Fukushima’s treated water discharge.

The International Atomic Energy Agency (IAEA) has led another round of independent water sampling at Japan's Fukushima Daiichi Nuclear Power Station as part of ongoing efforts to verify the safety of treated water being released into the sea.

The two-day mission, held from 8 to 9 July, focused on the 21st batch of Advanced Liquid Processing System (ALPS)-treated water. Samples were collected after the treated water had been diluted with seawater and just before its planned discharge. The mission is the tenth carried out under the IAEA's Additional Measures programme, which increases international participation and transparency in monitoring the discharge process. The IAEA had already confirmed that the tritium concentration in this batch remains well below Japan's operational limit, reinforcing earlier findings that the discharge is consistent with international safety standards.

Experts from Several Countries Join Independent Review

The sampling mission brought together specialists from China, the Republic of Korea, Russia and Switzerland alongside IAEA staff. Together, they independently collected samples from the discharge facilities to verify that radionuclide levels remain within internationally accepted safety limits.

The collected samples will now be analysed by laboratories in each participating country, as well as by the IAEA's Fukushima laboratory and Tokyo Electric Power Company Holdings (TEPCO), which operates the Fukushima plant. All participating laboratories belong to the IAEA's Analytical Laboratories for the Measurement of Environmental Radioactivity (ALMERA) network, recognised for its expertise in environmental radiation analysis. The independent testing allows multiple international laboratories to compare results, strengthening confidence in the monitoring process and ensuring that findings are verified by several trusted institutions.

Transparency Remains Central to Monitoring Efforts

The IAEA introduced the Additional Measures programme in October 2024 to expand international involvement in monitoring Fukushima's treated water discharge. The programme covers every major stage of the process, including sampling of treated water before and after dilution with seawater, along with seawater and fish collected near the power station.

During an earlier sampling mission in June, IAEA Director General Rafael Mariano Grossi said Japan's decision to allow countries to collect and analyse samples directly helps improve transparency, strengthen shared understanding and build confidence among neighbouring countries.

The Fukushima Daiichi Nuclear Power Station began releasing ALPS-treated water into the Pacific Ocean in August 2023. The IAEA continues to carry out an independent, impartial and science-based safety review to ensure the discharge remains in line with international safety standards.