No need to fear Japan’s release of nuclear wastewater

 

From Yosuke Kurotani

The Embassy of Japan would like to respond to an article titled Japan asked to reconsider nuclear wastewater release published on July 3.

Your writer wrote: “Previously, the German Institute for Marine Science claimed that the world’s strongest ocean currents along the coast of Japan would spread radioactive isotopes across the Pacific.” However, that is an opinion that completely ignores quantitative consideration.

The radioactivity per unit volume of Pacific seawater (background level) is about 0.1 to 1.0 Bq/L (with a range of one order of magnitude), mostly derived from naturally existing tritium.

The diffusion simulations (model range: 490km x 270km) of the release of the diluted advanced liquid processing system (ALPS)-treated water into the ocean showed that only areas within 3km of the discharging point exhibited radioactivity concentration (resulting in tritium concentration) higher than of seawater background, and the maximum value assessed at the boundary of the model range of the simulation was 0.00026 Bq/L. This figure is three to four orders of magnitude lower than the natural background level (about 0.1-1 Bq/L).

The concentration will be even lower outside the boundary due to further diffusion. The International Atomic Energy Agency (IAEA) reviewed this approach and states in the fourth report of the IAEA Task Force issued in April 2023: “The task force accepted Tepco’s (Tokyo Electric Power) reasoning that concentrations of tritium beyond this area will be even lower and therefore there is no scientific justification for redoing the calculations for a larger area.”

Your writer also wrote that former Maritime Institute of Malaysia (Mima) director-general first-admiral (Rtd) Chin Yoon Chin said “Japan should not use the ocean as a ‘dumping ground’ without taking into consideration the environmental harm that it was likely to cause”. Chin also called for regulations or established protocols to be put in place, saying that countries should be subjected to inspections by an appointed independent authorised body prior to releasing contaminants into the ocean.

And he also quoted Malaysian Institute of Defence and Security (Midas) chief executive major-general Ya’cob Samiran as saying: “If there are significant concerns or uncertainties, it may be prudent to re-evaluate the plan and explore alternative disposal options to prevent further harm to the environment and affected communities.”

However, Ya’cob pointed out that there were specific circumstances where the release of radioactive substances into the sea was allowed under certain guidelines and protective measures, such as those set out by the IAEA. “These discharges must be within the permissible limits and are subject to strict regulatory controls to ensure minimal environmental impact and human exposure,” he said.

In order to address the concerns above, we would like to explain the ALPS-treated water that Japan is about to release as follows:

1. The water to be discharged is diluted ALPS treated water. “ALPS treated water” itself has been sufficiently purified until the concentration of radioactive materials other than tritium is below the regulatory standard. Tepco will further dilute the ALPS treated water before discharging so that it will satisfy the regulatory standard for tritium. After the dilution, the concentration of tritium will be less than 1/40 of the national regulatory standard for NPS discharge (60kBq/L) and less than 1/7 of the WHO drinking water standard (10kBq/L), and the concentration of radioactive materials other than tritium will be less than 1/100 of the regulatory standard.

2. The assessment of radiological environmental impacts of discharging this water was conducted in line with the international guidelines. The result shows that the impact on humans and the environment would be minimal, even with biological concentration and long-term accumulation considered. The impact on humans is about one-thousandth of the radiation dose received from a single dental X-ray. The methodology and content of the radiological environmental impact assessment was reviewed by the IAEA.

3. Tepco and a third-party organisation is going to inspect all the ALPS-treated water before dilution and ensure that the diluted ALPS-treated water to be discharged into the sea meets the regulatory standards before the discharge as the results provided in the following website. In addition, in the IAEA’s report “First Interlaboratory Comparison on the Determination of Radionuclides in ALPS-Treated Water,” neither the IAEA nor the participating third-party laboratories detected any additional radionuclides other than tritium and the radionuclides to be measured and assessed.

4. The government of Japan has been taking measures in strict compliance with international law and fully in line with IAEA international safety standards, which have been developed in consultation with the IAEA secretariat and all IAEA member states, while continuing to undergo reviews by the IAEA, a specialised international organisation for nuclear energy, and will continue to do so in the future.

Therefore, as Chin points out, we have been reviewed by the IAEA, an independent and competent body, to confirm its safety. And, as Ya’cob points out, we will discharge the ALPS-treated water “under certain guidelines and protective measures, such as those set out by the IAEA.”

Following the announcement by the government of Japan of the basic policy on the handling of ALPS-treated water at the Tepco Fukushima Daiichi NPS on April 14, 2021, based on the terms of reference on a comprehensive framework for reviewing safety related-aspects of handling ALPS-treated water at Tepco’s FDNS, which was signed on July 8, 2021, IAEA conducted a series of reviews.

On July 4, IAEA director-general Rafael Mariano Grossi handed over the comprehensive report on the safety review of the ALPS-treated water at Fukushima Daiichi NPS to Prime Minister Kishida and the report was published accordingly.

The executive summary of the IAEA comprehensive report states the following conclusions: Based on its comprehensive assessments, the IAEA has concluded that the approach to discharge the ALPS-treated water into the sea, and associated activities by Tepco, NRA and the government of Japan, are consistent with relevant international safety standards.

The IAEA has concluded, based on its comprehensive assessment, that the discharge of the ALPS-treated water to the sea, as currently planned by Tepco, will have a negligible radiological impact on humans and the environment. - FMT

Yosuke Kurotani is the first secretary to the Embassy of Japan in Malaysia.

The views expressed are those of the writer and do not necessarily reflect those of MMKtT.