IAEA Conducts Seventh Mission to Monitor Fukushima Water Discharge

Ongoing International Oversight at Fukushima Daiichi

The International Atomic Energy Agency (IAEA) has undertaken its seventh mission focused on sampling seawater and selected fishery products near the Fukushima Daiichi Nuclear Power Station in Japan. This mission is part of the IAEA's continuous efforts to monitor the discharge of Advanced Liquid Processing System (ALPS) treated water, ensuring its consistency with international safety standards. The Agency's presence underscores its commitment to transparency and providing a science-based assessment to the international community.

ALPS Treated Water Discharge Commenced in 2023

The discharge of ALPS treated water into the Pacific Ocean began on August 24, 2023, following Japan's decision in April 2021 to release the stored water. The water, contaminated after the 2011 accident, undergoes treatment through the Advanced Liquid Processing System (ALPS), which removes most radionuclides, with the exception of tritium. Before discharge, the treated water is significantly diluted with seawater to ensure tritium concentrations are well below regulatory limits. This process is projected to continue for approximately 30 years.

IAEA's Comprehensive Safety Review and Findings

The IAEA established a Task Force in 2021, comprising IAEA and independent experts from 11 different countries, to review Japan's plan for the treated water. A comprehensive report issued in July 2023 concluded that Japan's approach was 'consistent with relevant international safety standards' and that the planned discharges would have a 'negligible radiological impact to people and the environment'. Subsequent review missions, such as those in October 2023 and May 2025, have consistently reaffirmed these findings, noting that the discharge facilities and equipment are operating in accordance with international safety standards and that a robust regulatory infrastructure is in place.

Monitoring and Verification Activities

During its missions, the IAEA Task Force reviews the facilities and equipment at the Fukushima Daiichi plant, and holds meetings with key stakeholders including Tokyo Electric Power Company (TEPCO), Japan's Ministry of Economy, Trade and Industry (METI), and the Nuclear Regulation Authority (NRA). The Agency also conducts independent sampling and analysis of the treated water and marine environment to corroborate data provided by Japan. These corroboration activities, including inter-laboratory comparisons, have confirmed the accuracy of TEPCO's measurements for radionuclides. To date, monitoring has shown no elevated tritium levels in nearby waters.

Commitment to Transparency

The IAEA maintains a continuous presence at the Fukushima Daiichi site, providing real-time data on the discharge to the international community. This ongoing monitoring and review process aims to ensure the safe and transparent implementation of the ALPS treated water discharge, upholding the highest international safety standards.