Fukushima Water Release Faces Fresh Independent Checks by Global Experts

Experts from the China Institute of Atomic Energy, the Korea Institute of Nuclear Safety and Switzerland’s Spiez Laboratory independently collected samples alongside specialists from the IAEA’s Fukushima laboratory.

International experts have collected fresh samples of treated water at Japan's Fukushima Daiichi Nuclear Power Station, adding another layer of independent scrutiny to a discharge process that remains under international review. Led by the International Atomic Energy Agency (IAEA), the sampling on 11 September brought together specialists from China, the Republic of Korea and Switzerland to check water at its source and support verification of compliance with international safety standards.

Independent Teams Collect Water at the Site

Experts from the China Institute of Atomic Energy, the Korea Institute of Nuclear Safety and Switzerland's Spiez Laboratory independently collected samples alongside specialists from the IAEA's Fukushima laboratory. Their work focused on water treated through the Advanced Liquid Processing System, known as ALPS, at the nuclear power station where water has been stored since the 2011 accident.

The mission was the eleventh sampling exercise conducted under the IAEA's Additional Measures, a framework that gives third-party experts direct access to water and environmental samples. Hands-on participation allows these specialists to collect material for their own laboratory testing, providing an independent basis for checking radionuclide concentrations, which measure the presence of radioactive substances.

Laboratory Testing Will Provide the Next Evidence

The collected samples will be analysed by the participating international laboratories, the IAEA and Tokyo Electric Power Company Holdings (TEPCO), the operator of the Fukushima Daiichi plant. The purpose is to provide further independent confirmation that the treated-water discharge continues to meet international safety standards; the sampling announcement does not present the results of those analyses.

Each participating international laboratory belongs to the IAEA's Analytical Laboratories for the Measurement of Environmental Radioactivity network, known as ALMERA. The laboratories were selected for their demonstrated expertise and analytical excellence, bringing specialist testing capabilities to a process in which reliable measurements are central to assessing compliance.

Monitoring Extends From Storage Water to the Nearby Sea

TEPCO began releasing ALPS-treated water in August 2023, and the discharge remains subject to an ongoing IAEA safety review. The agency introduced the Additional Measures in October 2024 to expand international participation, make sampling and analysis more transparent, and give outside experts opportunities to independently verify radionuclide concentrations through direct measurements.

The broader framework covers several stages of the discharge process, including treated water before dilution with seawater, water after dilution, and seawater and fish collected near the power station. This range of sampling supports an assessment that reaches beyond the water at the plant to the surrounding marine environment, forming part of the IAEA's continuing independent, impartial and technical review of the release.