In total, more than 1 million tons of water are planned to be dumped into the ocean.
Photo: REUTERS
A wave of panic spread through Japan’s neighboring countries. Specialists from the Land of the Rising Sun began pouring into the ocean water that was used to emergency cool the reactors of the Fukushima-1 nuclear power plant after its destruction during the 2011 tsunami. In total, it is planned to pour more than 1 million tons of water into the ocean. China and Hong Kong immediately banned imports of seafood from Japan, fearing that radioactively contaminated products would end up in stores. To calm the people, Japanese Prime Minister Fumio Kishida and his colleagues dined on camera with fish and other living things caught in the waters of Fukushima in the Pacific Ocean. That is why the official tried to demonstrate by his personal example that seafood is completely safe and that the population supplies food for future use in vain. What is the current situation of radiation safety after the Fukushima water spill into the ocean? What do the scientists think? We decided to ask the candidate of chemical sciences Andrei Egorin, senior researcher and head of the laboratory of sorption processes at the Institute of Chemistry of the Far Eastern branch of the Russian Academy of Sciences.
– Andrei Mikhailovich, was there an alternative to draining water into the ocean?
– The only alternative is long-term storage in special containers. Tritium has a half-life of 12.3 years, storage should last more than 10 half-lives, that is, more than 120 years. But in the case of Fukushima-1, the filling of these containers reached 97%, after which it was decided to throw them away.
– How effective was the water filtration system that was collected in Fukushima?
– An advanced liquid purification system (ALPS), well known to science, is used at the Fukushima-1 nuclear power plant to extract radionuclides. ALPS is not exactly a filtration system, but rather a complex of processes in which, among other things, dangerous radioactive elements are captured by the sediment, first with iron hydroxide and then with carbonates. After this, the purified water is sent to a series of filters containing sorbents and ion exchange resins. According to reports from the Tokyo Energy Company, ALPS allows radiation-contaminated liquid media to be purified of most radionuclides. However, this system does not allow tritium to be removed from the water.
– What is this element, how does it affect health?
– The problem is that tritium is very difficult to separate from water: its chemical properties are similar to those of hydrogen and it is difficult for a non-specialist to see the difference. Tritium filtration is a non-trivial and, most importantly, very expensive and energy-intensive procedure. The danger of its effects on the human body is a controversial topic. Tritium, along with background radiation, has always been present in the environment and we have evolutionarily adapted to the natural radionuclides that enter our bodies every day with food and water. Of course, tritium, like other radionuclides, causes local damage to cells, but this rarely has serious consequences, because cells have regenerative mechanisms. It is important to understand that the negative effects of tritium on the body depend directly on its concentration in water and the exposure time. Furthermore, there is still no data to show that the controlled release of tritium into the environment during normal operation of nuclear power plants in Korea, China and Canada would have obvious negative consequences. How might a particular shock affect people’s bodies? This must be studied in a very large sample of the population. I had never seen a job like this.
To calm the people, Japanese Prime Minister Fumio Kishida and his colleagues dined on camera with fish and other living things caught in the waters of Fukushima.
Photo: REUTERS
– Is there a threat of tritium dumped into the ocean reaching people through the marine food chain? Will the trail reach Russian waters?
– Probably yes. But this does not mean that the water suddenly becomes radioactive. There is most likely excess tritium activity above the background, but it will only be detectable using highly sensitive instruments.
Following the announcement by the Government of Japan about the drainage of water from Fukushima-1, our Laboratory of Sorption Processes at the Institute of Chemistry of the Far Eastern Branch of the Russian Academy of Sciences and the Far Eastern World Ocean Institute La Federal University quickly began control of the border waters. IMO specialists are currently on the scientific and educational expedition “Pacific Floating University” on the research vessel “Professor Multanovsky”, where they are taking water samples from Petropavlovsk-Kamchatsky to Vladivostok, including the Pacific coast, the Sea Okhotsk and the Sea of Japan. In the future, specialists from the Institute of Chemistry of the Far Eastern Section of the Russian Academy of Sciences will be able to analyze samples using high-precision equipment.”
– Mark Forman, assistant professor of nuclear chemistry in Sweden, said those who eat shellfish will only be exposed to “low” doses of radiation as a result of the discharge, in the range of 0.0062 to 0.032 microSv (Sievert is a unit of measurement of the effectiveness of ionizing radiation – Ed). At the same time, the safe dose is tens of thousands of times higher – up to 1000 microSv per year. How justified are such calculations?
– These estimates must be confirmed by a scientific publication, where the accuracy of the calculations and the adequacy of the model used can be verified. Unfortunately, I haven’t seen Mark Foreman’s calculations. I assume this is a highly averaged model. If the dosage for a seafood meal is indicated here, then it is a really small amount. You will receive this dose in one hour of flight at 12,000 meters altitude.
– The Japanese claim that the tritium content in Fukushima water is clearly below the WHO limit for drinking water of 10,000 Bq/l (the becquerel per liter is a unit of measurement for radioactivity – Ed.). How convincing are such claims?
– Unfortunately, there is some deception in the statements of Japanese scientists. The tritium activity of the source water in the Fukushima Daiichi reservoirs is significantly higher than the recommended 10,000 Bq/L, so it is diluted to some “recommended” values before being discharged. In the media, the resulting tritium concentration varies from 200 to 1500 Bq/l. The difficulty lies in the legal precedent: the dilution of liquid radioactive waste (liquid radioactive waste is different from the water that is discharged during a controlled discharge) and its subsequent discharge are expressly prohibited by international convention. Russian nuclear energy experts fear that other countries will dump liquid radioactive waste into the world ocean in the future.
– Is a million tons of water a lot on an ocean scale?
– The estimated mass of the world’s oceans is 1018 kg, 12 orders of magnitude greater than the volume of discharged water; the difference is colossal. If dilution is considered a valid option, then it must occur as quickly and uniformly as possible throughout the oceans so that the resulting tritium activity is negligible. Preliminary models suggest that the dilution process over several years may be accompanied by a temporary increase in tritium activity in some areas of the Pacific Ocean where the waters mix unevenly.
