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Speaking with members of the Japanese press club, IAEA Director General Rafael Rossi announces that Tokyo’s plan to release water from the ruined Fukushima Daiichi nuclear power plant is scientifically in line with safety standards. (Yonhap)

Few who have been watching the situation would have been surprised by the conclusion that the International Atomic Energy Agency (IAEA) reached in its final report on Thursday. Its decision that Japan’s plan to discharge contaminated water from the Fukushima Daiichi nuclear power plant into the sea is “consistent with international safety standards” was already foreshadowed by six interim reports dating back to April 2022.

Most notably, it concluded that “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.”

The IAEA did not include in its final report any verification of the performance of the Advanced Liquid Processing System (ALPS), a key facility responsible for reducing the radionuclide content of the contaminated water to below the permissible limit for discharge.

This lack of verification was based on a radiological environmental impact assessment conducted by TEPCO, Japan’s electric power corporation, which concluded that the contaminated water from the Fukushima plant was as safe as discharges from other nuclear plants in other countries.

This report presents the results of the IAEA’s review of the safety of the Fukushima contaminated water discharge plan that began in September 2021.

The review was divided into eight areas, including the radioactive characteristics of the water to be released, safety-related aspects of the systems and processes to control the release, the radiological environmental impact assessment (REIA), regulations and approvals for the release, the monitoring program, stakeholder engagement, and occupational radiation protection.

In the chapter of the report that reviewed the REIA, the IAEA said that, based on TEPCO’s assessment, “activity concentrations in international waters will not be influenced by the discharge of ALPS treated water into the sea and the transboundary impacts are therefore negligible.”

In the assessment, TEPCO used calculations based on an ocean dispersion model to predict that the area where tritium concentrations above 1 becquerel per liter would be expected would be limited to waters within three kilometers of the Fukushima Daiichi plant, and that the average tritium concentration in the surface waters 10 kilometers in all directions would be only 0.12 becquerels per liter.

The chapter reviewing the “protection of present and future generations and their environment” also concluded that “TEPCO’s marine dispersion models predict very insignificant concentrations of tritium and other radionuclides that will be undetectable or indistinguishable from background levels at the boundary of the modelling simulation area.”

“The results of the radiological environmental impact assessment show that the estimated dose to populations in neighbouring countries will be negligible,” it read.

Around 1.33 million metric tons of contaminated water, currently stored in tanks at the Fukushima nuclear power plant as shown here, will be released over the course of 30 years. (Yonhap)

The report also stated that, as the dose rates to three representative marine species (flat fish like flounders, crabs, and brown seaweeds) are more than one one-millionth lower than the reference levels set by the International Commission on Radiological Protection. “The IAEA is confident that the international environmental protections objectives will be amply met by the controls in place for the discharge of ALPS treated water and that the dose rates to biota are negligible compared to the international safety criteria set by ICRP.”

In Japan, the government and ruling party emphasize that the discharge of contaminated water will have a negligible impact on the country based on simulations of the spread of these radionuclides in the ocean.

However, these simulation results only explain the timing and concentration of tritium in domestic waters. They are far from a comprehensive assessment of the biological effects of radioactive material released into the ocean, including its accumulation through the food chain.

Greenpeace and other environmental organizations have pointed out that the environmental impact assessment, which is based on marine dispersion models, does not take into account the impact on marine ecosystems and neighboring countries, including South Korea.

Furthermore, the radioactive water discharge plan is predicated on the stable operation of the ALPS throughout the discharge period, which will keep the radionuclide content of the contaminated water below the permissible discharge threshold.

However, the IAEA and Japan have a fundamental limitation in their review of the discharge plan in that they have included the facilities to transport and dilute the contaminated water as subjects of monitoring, but not the system, ALPS, that will filter it.

In May, Korea announced that it would soon announce the results of verifying the performance of ALPS by analyzing the raw data of contaminant concentrations at the entrance and exit of ALPS obtained during the site inspection of the Fukushima Daiichi nuclear power plant.

However, it is unlikely that the results of the analysis of the data provided by the Japanese government, without verification through sample analysis, will resolve concerns about the reliability of ALPS.

By Kim Jeong-su, senior staff writer

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