VLADIVOSTOK. Aug 26 (Interfax) - Elevated tritium concentrations have been detected in samples taken by a Russian expedition studying the presence of radionuclides in the Pacific after water discharges from the damaged Fukushima Nuclear Power Plant No. 1, the Ilyichev Pacific Oceanological Institute of the Russian Academy of Sciences' Far Eastern branch said in a statement.
"Lab analysis of the first water samples taken during an expedition of the Akademik Oparin research ship showed elevated tritium concentrations in the main branch of the Kuroshio Current, which would be expected due to the pattern of currents in the region, as well as elevated tritium levels outside the South Kuril Islands," the statement said.
A new scientific expedition has been arranged for thorough examination of waters outside the Kuril Islands and the southern part of the Sea of Okhotsk, which is a major fishing area of Russia. The Professor Gagarinsky research vessel has departed from Vladivostok on a month-long mission to take samples of water, marine biota and bottom sediments.
The structure of currents and the type of water exchange between the Sea of Okhotsk and the Pacific Ocean will be studied, alongside ocean water transfer through the Kuril Strait. Scientists are expecting to obtain new data on gas exchange processes, biogeochemical characteristics of waters and their inter-annual variability amid global warming and increasing anthropogenic load. The expedition includes scientists from the Ilyichev Pacific Oceanological Institute, and the Yelyakov Pacific Institute of Bioorganic Chemistry of the Russian Academy of Sciences' Far Eastern branch.
As reported, the Akademik Oparin research vessel went on an expedition in June-July to assess the content of radionuclides in the Pacific amid the ongoing water discharge from the damaged Fukushima NPP 1.
Measurements were taken in the Sea of Japan and the Sea of Okhotsk, in the Pacific Ocean to the east of Japan, and from the east coast of Sakhalin Island in the north to the main branch of the Kuroshio Current and subtropical waters in the south.
The scientists examined the main branch of the Kuroshio Current, large eddy formations separating from it to the south and north for a month and a half. They also explored the area of interaction of the Kuroshio and Oyashio Currents, which is a focal point from the angle of safety of the Russian fishing zone near the Kuril Islands.
Scientists collected more than 120 tonnes of seawater samples from various depths for research. In addition to tritium, it is planned to assess the content of other radioisotopes - cesium, strontium, beryllium, radium, and lead. Laboratory analysis of the first samples confirmed that the content of cesium-137 in the ocean was significantly lower than the permissible limit, and 2-50 times lower than it was in 2012.