IAEA monitors treated water released from Fukushima Daiichi

29 August 2023


The International Atomic Energy Agency (IAEA) is providing live data from Japan on the release of treated water from the Fukushima Daiichi NPP on the IAEA website. The data includes water flow rates, radiation monitoring data and the concentration of tritium after dilution. Fukushima NPP operator, Tokyo Electric Power Company (Tepco), has now begun the controlled discharge of the water into the sea. At the same time, Tepco began transmitting data from various points in the process to the IAEA.

The water, used to cool the melted reactor cores in the aftermath of the 2011 nuclear disaster at Fukushima, is stored in 1,046 huge tanks at the plant containing more than 1.3m tonnes and total storage capacity has been reached. The contaminated cooling water and groundwater is treated by the Advanced Liquid Processing System (ALPS), which removes most of the radioactive contamination, with the exception of tritium. The water is diluted so that tritium levels fall below national regulations before it is released, following multiple checks, through an undersea tunnel one kilometre offshore. The release will take place over several decades.

IAEA says it is continuing its impartial, independent and objective safety review of Japan’s discharge of the water. The Agency issued its comprehensive report on the safety review of the ALPS-treated water in July. In the report, the IAEA concluded that Japan’s approach and activities to discharge ALPS-treated water are consistent with relevant international safety standards. The report noted that the controlled, gradual discharges of the treated water to the sea, as currently planned and assessed by Tepco, would have a negligible radiological impact on people and the environment.

In addition to the live monitoring, the IAEA will continue its safety review during the discharge phase by having a continuous on-site presence, meeting IAEA Director General Rafael Mariano Grossi’s commitment to be involved before, during and after the water discharges.

IAEA experts will observe onsite activities related to the ALPS-treated water discharge, including samples and measurements, and they will interface with Tepco and officials from Japan’s Nuclear Regulation Authority (NRA). IAEA will also organise review missions periodically to observe activities on site and to request updates and additional data from Japanese authorities.

The IAEA’s independent corroboration activities will also continue during the entirety of the discharge, expected to take decades, and will involve IAEA laboratories and third-party laboratories. Over time, the IAEA will display the results of this independent corroboration of source and environmental monitoring, as well as the results of its corroboration of the capabilities of relevant Japanese individual monitoring services for occupational radiation protection. The results are published on the website to enhance the availability of relevant data for interested parties.

Gustavo Caruso, Director and Coordinator for the ALPS Safety Review at the IAEA and Chair of the Task Force explained that all of these activities will work together to provide a comprehensive picture of the activities taking place at Fukushima related to the ALPS-treated water discharge and ensure these activities are consistent with relevant international safety standards. “The data provided by Tepco, and displayed both by Tepco and IAEA, is just a single piece of the overall monitoring approach and the IAEA’s ongoing safety review,” he said.

Tepco, announcing start of the release, said in a statement: “We would like to express our deepest apologies for the great concern and burden that the accident at our Fukushima Daiichi Nuclear Power Station has caused to everyone in the community and society at large.” Tepco is providing detailed, up-to-the minute information on a special “Treated Water Portal Site” about ALPS and strontium-treated water. In notes that the 1,046 tanks containing ALP-treated water include 30 for measurement and confirmation. Another 24 tanks contain strontium-removed water. In addition, 12 storage tanks are being used for fresh water treated with a reverse osmosis facility and one tank is being used for concentrated seawater.

In preparation for the first release, Tepco transferred 1 cubic metre of ALPS-treated water to the dilution facility using the special transfer facilities. This water was then diluted with about 1200 cubic metres of seawater and allowed to flow into the discharge vertical shaft (upstream water tank). The water stored in the discharge vertical shaft was then sampled.

"The results showed that the analysis value is approximately equal to the calculated concentration and below 1500 becquerels per litre," Tepco said. "The sample of the water was also analysed by the Japan Atomic Energy Agency, which confirmed the value to be below 1500 Bq/litre." For comparison, the World Health Organisation guideline for drinking water is 10,000 Bq/litre.

An IAEA Task Force was set up to advise Japan and the Agency opened an office at the Fukushima plant in July. "IAEA experts are there on the ground to serve as the eyes of the international community and ensure that the discharge is being carried out as planned consistent with IAEA safety standards," said Grossi. "Through our presence, we contribute to generating the necessary confidence that the process is carried out in a safe and transparent way."

Confirmed that the discharge had begun, the Agency noted: "The IAEA's independent on-site analysis confirmed that the tritium concentration in the diluted water that is being discharged is far below the operational limit of 1500 becquerels per litre." It confirmed that the IAEA said it will have a presence on site for as long as the treated water is released The IAEA will also organise review missions periodically to observe activities on site and to request updates and additional data from Japanese authorities. 

Despite IAEA monitoring and assurances from Tepco, however, protests have continued both in Japan, especially from fishing communities, and from neighbouring states and environmental organisations. Pledges of support and compensation from the Japanese government have failed to lessen the anxiety of local fishermen. Japanese fishing groups fear the release will do more harm to the reputation of seafood from the Fukushima area. They are recovering from the damage caused by the original Fukushima accident. “We now have this water after all these years of struggle when the fish market price is finally becoming stable,” one fisherman told AP.

China responded to the water release with a ban, effective immediately, on imports of all aquatic products from Japan. Previously, China had undertaken strict inspections of seafood from Japan. In South Korea, despite government acceptance of the water release, protests and panic sales of sea salt increased. Hong Kong and Macau announced separate bans on Japanese seafood from ten regions.

During a discussion at the United Nations General Assembly a day after the initial water release, Geng Shuang, China’s deputy permanent representative to the UN said Japan’s decision disregarded public interests, and risked nuclear pollution, noting that the ocean is the common property of all mankind. Geng said China strongly urges Japan to stop the ocean discharge plan, communicate with neighbouring countries with sincerity and good will, dispose of the nuclear-contaminated water in a responsible manner and accept rigorous international oversight. “It has transnational implications, it’s not a domestic matter of Japan alone.… I’d like to call on the Japanese government to address squarely the legitimate concerns of stakeholders and to engage in good faith to address this discharge of water in a responsible manner.”

Indonesia’s Nuclear Energy Regulatory Agency (Bapeten), on the other hand accepts that any residual tritium would become diluted on entering the open sea, with negligible impacts on distant shores. Bapeten spokesman Abdul Qohar Teguh Eko Prasetyo said the released wastewater would be relatively safe for the environment.


Image: Japan’s Tokyo Electric Power Company is transmitting data from various points of the controlled discharge of ALPS-treated water into the sea (courtesy of A Vargas/IAEA) 



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