The IAEA Task Force established to review the safety of Japan’s plans to discharge to the sea contaminated water treated using the Advanced Liquid Processing System (ALPS) stored at the Fukushima Daiichi NPP has released its third report. The new report sets out how the Agency is conducting its own independent checks of key data related to monitoring the safety of the treated water.

This corroboration work is one of the three components in the Task Force’s review of Japan’s plans to ensure they are in line with IAEA Safety Standards. The review also comprises assessments of the technical plans and of regulatory activities and processes related to the water discharge.

The report summarises the main elements of the IAEA’s corroboration activities and explains the methodologies to be used, providing an update on the progress made to date and possible future activities.

Fukushima Daiichi NPP owner/operator Tokyo Electric Power Company (Tepco) is required to determine the characteristics and activity of the ALPS treated water planned for discharge to the sea. This characterisation is used as a basis to establish and implement effective monitoring programmes to ensure that any public exposure due to the discharges is adequately considered.

The report focuses on how IAEA will conduct its own independent checks of the radiological contents of the water stored in the tanks and how it will analyse environmental samples (for example seawater and fish) from the surrounding environment.

This corroboration of data will be conducted using interlaboratory comparisons involving both IAEA laboratories as well as independent third-party laboratories from France, South Korea, Switzerland, and the USA – all members of the network of Analytical Laboratories for the Measurement of Environmental Radioactivity (Almera). The report also covers how the IAEA will independently review Japanese capabilities for measuring the radiation exposure of workers at the plant. It includes details on the first collections of treated water samples from the tanks, as well as environmental samples, in 2022.

“This independent work will build confidence in the accuracy of data provided by Tepco and the Japanese authorities and will give another layer of assurance that they are adhering to relevant IAEA Safety Standards,” said Gustavo Caruso, Director of the IAEA Department of Nuclear Safety & Security and Chair of the Task Force.  

The initial results will be made available in 2023 before the planned discharges of the ALPS treated water begin. Subsequent results will be included in future reports that will provide the details of the technical evaluation as well as information for the public on how to read and interpret the data. 

“Japan maintains the overall responsibility for the safety of its nuclear facilities and activities, including the discharge of the treated water. However, the IAEA’s ongoing corroboration activities are a critical element to check the accuracy and validity of data reported by TEPCO and the Japanese authorities, therefore building confidence in the overall IAEA safety review,” added Caruso.

Image: Aerial view of Fukushima No. 1 (courtesy of KYODO)