The administration of Japanese Prime Minister Yoshihide Suga announced its decision to release stored cooling water held in tanks surrounding the damaged Fukushima No. 1 nuclear power plant on Tuesday, 13 April. Tokyo Electric Power Company (TEPCO) was instructed to make plans to begin releasing the water in two years.
There is limited room around the factory to increase the number of tanks, and the space will be needed for future efforts to remove damaged fuel rods. Other methods of disposing of the approximately 250 million gallons of stored water were evaluated by a government panel earlier this year, but release to the ocean was considered the most practical.
In practice, releasing the cooling water is not very dangerous. It has already been treated by multiple facilities, including a multi-nuclide removal facility – an advanced liquid processing system, or “ALPS” – which removed most of the radioactive materials, including cesium and strontium, but not tritium.
Tritium is difficult to separate from water because it closely resembles hydrogen, which is a natural component of water. Tritium has a radioactive half-life of 12.3 years, but its biological half-life in the human body is only 10 days, and in fish, it is less than two days. This is because tritium easily bonds to water, replacing the hydrogen atom. Thus, as fish take in and expel water, the tritium is carried away rather than accumulating in tissues and moving up the food chain.
Before the accident, tritium in cooling water was diluted with circulated sea water so that the allowable concentration was not exceeded, and the diluted tritium was routinely released into the sea. This is the standard procedure for nuclear power plants around the world, including in China and South Korea, which have nonetheless expressed concern about the plan.
“This action is extremely irresponsible and will pose serious harm to the health and safety of the people in neighboring countries and the international community,” the Chinese Foreign Ministry said about the plan.
South Korea has demanded that the decision be taken only through consultation with Japan’s neighboring countries, and is referring the matter the to the United Nations Convention on the Law of the Sea, under which countries are obligated to refrain from inflicting environmental damage on neighboring countries and must share details on how to minimize the damage if they do.
“The method Japan has chosen is both technically feasible and in line with international practice. Controlled water discharges into the sea are routinely used by operational nuclear power plants in the world and in the region,” International Atomic Energy Agency Director General Rafael Mariano Grossi said in a video message included in a press release.
The main danger of the policy is not actual harm, but rather public perceptions about the safety of seafood from Fukushima and its neighboring prefectures.
Suga met with National Federation of Fisheries Cooperative Associations President Kishi Hiroshi on 7 April, but failed to win his approval, as local fishermen are concerned that their products will be shunned and bans on their importation by several countries will be maintained.