The Japanese Government has provided the IAEA with a report that summarizes the events and highlights the progress related to recovery operations at the Fukushima Daiichi Nuclear Power Station. The IAEA provided its assessments, which are contained in full at the end of the report.
This assessment has been performed on aspects presented in the February 2021 report 'Events and highlights on the progress related to recovery operations at Fukushima Daiichi Nuclear Power Station'. It does not include recent developments that will be taken into consideration in a next report.
Achieving the milestone of completing the removal and treatment of stagnant water in the target buildings
The IAEA acknowledges that the removal and treatment of the stagnant water in the target buildings has been successfully completed and that the associated milestone has been achieved.
Achieving the milestone of reducing the amount of generated contaminated water and completion of analysis of ALPS secondary treatment performance confirmation tests
The IAEA acknowledges that the milestone of reducing the amount of generated contaminated water has been achieved. The IAEA acknowledges that ALPS secondary treatment showed good performance. The Agency considers that both results will have a positive impact on realistic and sustainable contaminated water management including decision on the disposition path. The IAEA notes that, in the future, a third-party organization will conduct analyses of samples from the ALPS secondary treatment.
Delay in the trial fuel debris retrieval from Unit 2 due to COVID-19 pandemic in the United Kingdom
The IAEA notes the delay in trial of fuel debris retrieval from Unit 2 and acknowledges Japan’s efforts to minimize the process delay within nearly one year.
Fuel removal from the Spent Fuel Pool in Unit 3
The IAEA acknowledges the ongoing progress towards completion of fuel removal from the SFP in Unit 3.
Sea area monitoring results
Based on the information provided by Japan, the IAEA notes that no significant changes were observed in the monitoring results for seawater, sediment and marine biota, including fishery products, during the period covered by this report. The levels measured by Japan in the marine environment are low and relatively stable. For the purpose of public reassurance, the IAEA encourages the continuation of sea area monitoring. Furthermore, the IAEA considers that the ongoing data quality assurance programme that is in place is important for facilitating transparency and promoting confidence in the accuracy and quality of the results of the monitoring programme to all stakeholders.
Food products
Based on the information provided by Japan, it is noted that an assessed effective ingestion radiation dose for radiocaesium of less than 0.0010 mSv/year is less than 0.1 % of the 1 mSv/year dose criterion for radionuclides in food specified in International Basic Safety Standards1/ . In addition, an ingestion dose of less than 0.0010 mSv/year is a small fraction of the doses that arise from the ingestion of naturally occurring radionuclides in food. For example:
- International assessments of typical doses received from the consumption of natural radionuclides have been published by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and calculate a worldwide average ingestion dose of 0.31 mSv/year with a typical range estimated at 0.2 – 0.8 mSv/year2/. Most of this dose is assessed as being due to the naturally occurring radionuclides of lead-210, polonium-210 and potassium-40. The radiocaesium ingestion doses calculated by the Japanese Ministry of Health Labour and Welfare from their duplicate diet study of 2019 are less than approximately 0.3 percent of the worldwide average annual dose from the ingestion of natural radioactivity.
- A duplicate diet study3/ undertaken in the Aomori Prefecture of Japan during 2006 to 2010 (before the accident at the Fukushima Daiichi nuclear power plant) reported a mean annual ingestion dose of 0.47 mSv/year with most of this ingestion dose being attributed to the naturally occurring radionuclides: lead-210, polonium-210 and potassium-40. The radiocaesium ingestion doses calculated by the Japanese Ministry of Health Labour and Welfare from their duplicate diet study of 2019 are less than approximately 0.2 % of this mean annual ingestion dose for background levels of radioactivity.
Based on the information provided by Japan, it is noted that the situation regarding the safety of the food supply, fishery and agricultural production continues to remain stable. Food restrictions continue to be revised and updated as necessary in line with food monitoring results. Approximately four thousand results are reported each month for food samples collected over the reporting period and this attentiveness to monitoring levels of radiocaesium in food products continues to indicate the vigilance of the authorities in Japan and their commitment to protecting consumers and trade. Monitoring, appropriate regulatory action and public communication are helping to maintain confidence in the safety of the food supply.
Based on the information that has been made available, the Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture understands that measures to monitor and respond to issues regarding radionuclide contamination of food are appropriate, that the food supply chain is controlled effectively by the relevant authorities and that the public food supply is safe.
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1/ Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards, IAEA Safety Standards Series No. GSR Part 3, IAEA, Vienna (2014). See more particularly Requirement 51.
2/ UNSCEAR, Sources and Effects of Ionizing Radiation, Vol. I, Annex B (2000)
3/ Y Ohtsuka et al Daily radionuclide ingestion and internal radiation doses in Aomori Prefecture, Japan. Health Physics 105, 4, 340 – 350 (2013)