The International Atomic Energy Agency (IAEA) has commissioned Japanese experts to independently observe and document the collection of seawater, marine sediment and fish samples from coastal waters in Fukushima Prefecture. The aim is to support the quality assurance of data collection and analysis by Japanese laboratories for radioactivity measurements.

The 4-20 November mission is the tenth organised by the IAEA, at the request of the Japanese Government, to verify that sea area monitoring around the Fukushima Daiichi nuclear power plant remains comprehensive, credible and transparent.

Unlike the previous nine missions when the IAEA sent its own team, including international experts, three independent Japanese experts will this time monitor the sampling on behalf of the Agency due to COVID-19 travel restrictions.

Since 2014, the IAEA has organised missions to support the collection of marine samples for interlaboratory comparisons of radioactivity analyses. For this mission, the independent domestic experts in environmental radioactivity will observe the sample collection of seawater and marine sediment samples near the Fukushima plant, and fish caught by commercial fishing operations in Fukushima Prefecture.

The team will report directly to the IAEA on the integrity of sample collection, identification, tracking and pre-treatment. Analyses of the samples will be conducted at laboratories in Japan and at the IAEA, where the quality of the measurement results will be evaluated.

The mission is a follow-up to the 2013 report by the IAEA International Peer Review Mission on mid- and long-term roadmap towards the decommissioning of Tepco's Fukushima Daiichi 1-4, which reviewed Japan's efforts to decommission the plant.

In this report, the IAEA recommended that Japan should follow an extensive data quality assurance programme to build stakeholder confidence in the accuracy and quality of the sea area monitoring data. A 2017 analysis report of six inter-laboratory comparisons and sampling missions conducted from 2014 to 2016 concluded that Japanese laboratories analysing marine samples from near the Fukushima Daiichi nuclear power station produced reliable data.