Radioactive substances from the Fukushima No. 1 nuclear plant will dilute to negligible levels in the ocean, but the area close to the site remains a problem, the chief researcher at the Meteorological Research Institute said.
Radioactive substances from the Fukushima No. 1 nuclear plant will dilute to negligible levels in the ocean, but the area close to the site remains a problem, the chief researcher at the Meteorological Research Institute said.
Michio Aoyama reported his findings on the circulation of radioactive substances released into the sea at the Scientific Forum of the International Atomic Energy Agency (IAEA) in Vienna in September.
Excerpts from the interview follow:
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Other than in the area right next to the nuclear power plant, the radiation should become diluted and have no effect on fish.
In comparison, the amount released due to the Fukushima accident is around 15 petabecquerels.
There were 1 to 2 becquerels of cesium per cubic meter in the seas off Japan before the accident, but the level rose, on average, by 20 percent immediately afterward.
However, the additional cesium has not had a significant effect on the vast waters, and the concentration in the open ocean is returning to pre-accident levels.
Following that cesium, we have learned that they proceed eastward into the Pacific Ocean and sink into deep waters before reaching the North American continent. They then turn south and head into the Indian Ocean, the South Pacific or return to the Japanese archipelago.
Surveys conducted after the Fukushima accident have shown the same phenomenon. I believe the radioactive substances will follow a similar pattern of behavior in the future as well.
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Born in 1953, Michio Aoyama graduated from Meteorological College and earned his Ph.D. from the Graduate School of Natural Science and Technology at Kanazawa University. He has served as a member of the Nuclear Regulation Authority’s investigative commission on ocean monitoring.