Recently, I have seen some articles claiming that Japan is planning to discharge alleged “contaminated water” into the Pacific Ocean, one of which is the article ‘Is Japan going to dump nuclear contaminated water in the Pacific?’ in Business Recorder of March 14.

Though the article refers to my post in Daily Times of April 7, 2023 and quoted some sentences from it, some of the most important points that I made are missing.

To avoid reader’s confusion and promote correct understanding, I would take this opportunity to inform you of some basic facts regarding Japan’s plan to discharge ALPS treated water into the sea.

1: Why does Japan have to discharge the water?

After the devastating earthquake and tsunami hit and crippled Tokyo Electric Power Company’s (TEPCO) Fukushima Daiichi Nuclear Power Station on March 11, 2011, tons of water have been required to cool the fuel debris at the plant’s reactor building, and the water becomes contaminated with radioactive materials.

The contaminated water has been purified with Advanced Liquid Processing System (ALPS), and stored in tanks on site.

However, it is not possible to keep the ALPS treated water in tanks forever. The number of storage tanks on the site exceeds a thousand, which is an obstacle to secure a site for the planned decommissioning of the plant.

This is why, following years of discussion and consideration among experts, the Government of Japan announced in April 2021 its Basic Policy on handling of ALPS treated water.

It says that the water will be discharged into the sea in about two years subject to the approval of Japan’s independent Nuclear Regulation Authority (NRA). The Government of Japan also announced that it will receive thorough review of the IAEA. The discharge is expected to start this year subject to the completion of construction work, NRA Pre-Service Inspections and publication of the IAEA’s comprehensive report.

2: Is it really safe?

I need to stress that Japan will never allow the discharge of “contaminated water” that exceeds regulatory standards into the sea.

There are two different types of water on the Fukushima Daiichi site: one is “contaminated water” and the other is “ALPS treated water.”

With this ALPS treatment, the concentration of radioactive materials other than tritium in the water becomes below the regulatory standards. The treated water will then be diluted with sea water prior to the discharge. As a result, the concentration of tritium will be 1/40 of the regulatory standard and 1/7 of the WHO drinking water standard.

The radioactive materials other than tritium will be further diluted, with its concentration less than 1/100 of the regulatory standard.

In addition, simulation of the diffusion of ALPS treated water discharged into the sea shows that the concentration of tritium is higher than that of seawater in the area only within 3km of the power station (Tritium exists in nature, and is found in rain, sea and tap water, as well as inside of our body as a form of triteated water).

It is scientifically clear that the discharge of ALPS treated water into the sea will not cause substantial pollution of or significant and harmful changes to the marine environment. Nevertheless, as an additional precautionary measure for the protection and preservation of the marine environment, the radiological environmental impact assessment (hereinafter referred to as “REIA”) was conducted by TEPCO in line with the international standards.

In the REIA, the possible effect of bioaccumulation and long-term accumulation was fully taken into account. The result of the assessment shows that the impact on humans and the environment would be minimal; the annual radiation impact on humans from the discharged water would be about 0.1% of the radiation dose received from a single dental x-ray.

3: Discharging water is common practice around the world

Is Japan’s planned discharge of water into the sea unprecedented or dangerous? Certainly not: it is common practice around the world. At nuclear facilities both at home and abroad, tritium is being discharged as liquid waste into the environment such as rivers and the sea, in compliance with their own domestic laws and regulations.

Japan’s Subcommittee on the Handling of ALPS treated Water (the ALPS Subcommittee) in April 2020 concluded that the discharge into the sea “can be more reliably implemented because it is commonly practiced in nuclear power plant around the world, the safety of the discharge facilities has been demonstrated, and the discharge into the sea can be most accurately monitored.”

The IAEA also noted that “the recommendations made by the ALPS Subcommittee were based on a sufficiently comprehensive analysis and on a sound scientific and technical basis” and that the discharge into the sea is “technically feasible.”

I would like to highlight that the amount of tritium in ALPS treated water is smaller than that of discharged water from most nuclear power plants and other facilities in other countries, and that Japan will manage the annual discharge volume of tritium so that it will not exceed the target discharge management value for Fukushima Daiichi set before the accident.

4: Japan’s plan is under the IAEA review

With regard to handling the ALPS treated water, Japan has been taking measures strictly abiding by relevant international law while giving due considerations to international practice. In order to ensure the discharge plan and related activities will be implemented in a safe and transparent manner, the discharge plan, including TEPCO’s REIA and the domestic regulatory process, has undergone the strict review by the Task Force established by the IAEA, the most authoritative and independent organization in the field of nuclear safety.

The Task Force is comprised of experts from the IAEA Secretariat and 11 internationally-recognized experts appointed by the IAEA from various countries including our neighboring countries; Argentina, Australia, Canada, China, France, Marshall Islands, Republic of Korea, Russian Federation, United Kingdom, United States and Vietnam. The IAEA’s review will continue even after the commencement of the discharge in order to monitor its safety.

5: Japan maintains full transparency

Japan has been making strenuous efforts in promoting understanding of the international community and listening to concerns over the discharge plan. It has been providing information based on scientific evidence and facts, and will continue to do so in a highly transparent and timely manner.

Specifically, Japan has held a number of briefing sessions for the diplomatic missions in Tokyo and similar meetings at international conferences including those organized by the IAEA based on scientific evidence, with an emphasis on providing sufficient data.

As I wrote above, Japan’s plan of discharging ALPS treated water is safe, and is consistent with world’s common practice and international standards. I hope this article promotes readers’ correct understanding of Japan’s plan and its sincere efforts for ensuring safety for humans and the environment.

The article does not necessarily reflect the opinion of Business Recorder or its owners