Tokyo, September 12, 2026: The International Atomic Energy Agency (IAEA) is leading a team of international experts in Japan this week to independently collect samples of Advanced Liquid Processing System (ALPS)-treated water at the Fukushima Daiichi Nuclear Power Station.

The sampling forms part of additional measures established under the IAEA’s framework for monitoring the treated water at the site. The work is focused on source monitoring, allowing experts to independently examine samples taken directly from the facility.

Independent Monitoring at Fukushima

The Fukushima Daiichi Nuclear Power Station has remained under international scrutiny since the 2011 nuclear accident. The IAEA has established monitoring activities designed to provide independent scientific information about the treated water and its release into the sea.

As part of the latest activity, international experts are participating in the sampling process alongside Japanese counterparts. Independent sampling provides an additional layer of verification for analytical results concerning the treated water.

What Is ALPS-Treated Water?

ALPS is a water treatment system used at the Fukushima Daiichi site to remove most radioactive substances from contaminated water generated during the management of the damaged nuclear facility.

After treatment, the water is subject to monitoring and other procedures before its controlled discharge. Tritium, a radioactive form of hydrogen that is difficult to remove from water, remains and is diluted before discharge.

The IAEA’s monitoring activities examine the treatment and discharge process using independent sampling and analysis to assess whether it is consistent with relevant international safety standards.

Role of International Experts

The participation of specialists from different countries is intended to strengthen the independent nature of the monitoring process. Samples can be analyzed by participating laboratories and compared with results produced through Japan’s monitoring programs.

Such independent measurements are important for transparency and for providing reliable scientific information to the international community.

The IAEA has repeatedly emphasized that its monitoring work at Fukushima is intended to provide an independent assessment of the safety-related aspects of Japan’s approach to managing and discharging ALPS-treated water.

The latest sampling mission represents another step in the continuing international monitoring effort at Fukushima Daiichi and is designed to provide additional scientific data on the treated water at its source.