UK-Australia International Joint Research Team
Comparison with French nuclear power plant discharge
“Radiation concentration is 1/450th of the level.”
Japan began the second discharge of contaminated water stored in the K4 tank of the Fukushima Daiichi Nuclear Power Plant on the 5th. Last month, Tokyo Electric Power Company and the International Atomic Energy Agency (IAEA) each analyzed samples of contaminated water subject to secondary discharge and confirmed that the tritium (tritium) concentration met the discharge standards.
An international joint research team from the UK and Australia led by Jim Smith, a professor at the School of Environmental Studies at the University of Portsmouth, published research results in the international academic journal ‘Science’ on the 5th (local time), showing that Fukushima contaminated water is unlikely to have a negative impact on the marine environment and the human body. revealed. It is attracting attention as it is a comparative study result of a French nuclear power plant that actually discharged tritium-containing water into the ocean for 20 years.
The research team said, “As a result of the analysis, Japan’s discharge of contaminated water is carried out under a thorough management system, so it is unlikely to cause harm to the human body or destroy the marine ecosystem.” They added, “France’s La Hague nuclear power plant discharged water into the ocean from 1996 to 2016. “Compared to tritium water, the amount of contaminated water discharged by the Japanese government as planned is very small,” he said.
The representative radioactive isotope that is not filtered out by the polynuclide removal system (ALPS) in the Fukushima contaminated water discharged into the ocean is tritium. Tritium mixes with seawater in the form of water and is called tritium water. Tritium water is diluted with seawater and the concentration is measured to check whether it meets the discharge standards. It is known that if tritium above a certain concentration continuously enters the living body, it can cause genetic modification or abnormalities in reproductive function, like other radioisotopes.
According to the research team, France’s La Hague nuclear power plant discharged tritium water with an annual average radioactivity of about 8,000 to 12,000 terabecquerels (TBq) into the narrow Strait of Dover between France and the UK every year for 20 years. The research team stated that this is equivalent to 0.01 microsievert (μSv/year) per year in terms of the amount of radiation exposed to the human body. It is 1/100,000th of the annual radiation exposure limit of 1 millisievert (1000 μSv) for the general public.
The research team stated that no impact of the discharge of La Hague contaminated water on the surrounding ecological environment was found. The concentration of tritium in seawater near La Hague was about 50 Bq per L. They added that genetic damage has been observed in carp near a Canadian nuclear power plant exposed to at least 7,700 Bq of tritium water per L and at most 21,900 Bq of tritium water, but that it did not affect the carp’s survival or various health indices.
The research team explained, “According to Japan’s plan, the radioactivity concentration of the annual tritium water discharge contained in Fukushima contaminated water is 22 TBq, which is about 1/450th of the annual average radioactivity concentration contained in the La Hague discharge.” In addition, the Fukushima nuclear power plant is a boiling water reactor (BWR) that emits a smaller amount of tritium water than other nuclear power plants, and the Japanese government reduced the amount of contaminated water discharged in consideration of concerns from neighboring countries and opposition from local fishermen.
The research team compared the amount of tritium emitted annually from nuclear power plants around the world based on reports from the IAEA, Woods Hole Oceanographic Institution (WHOI), the U.S. Environmental Protection Agency, and Japan’s Ministry of Economy, Trade and Industry. According to comparative results, the radioactivity concentration of tritium occurring naturally in the Pacific Ocean is more than 10,000 TBq per year. The radioactivity concentration of tritium emitted annually by the La Hague nuclear power plant is approximately 10,000 TBq, and the Bruce Nuclear Power Plant in Canada emits tritium at a concentration of approximately 1,000 TBq per year. Korea’s Kori Nuclear Power Plant exports about 50 TBq of tritium per year. The amount of emissions from the Fukushima nuclear power plant is 22 TBq per year, which is a relatively low figure.
The research team concluded, “If the discharge of Fukushima contaminated water is carried out as planned, it will not pose a real threat to marine life in the Pacific Ocean or consumers of Fukushima seafood.”
Park Geon-hee, Donga Science
Source: Donga
Mark Jones is a world traveler and journalist for News Rebeat. With a curious mind and a love of adventure, Mark brings a unique perspective to the latest global events and provides in-depth and thought-provoking coverage of the world at large.