Plutonium that is believed to have come from the crippled Fukushima No. 1 power plant has been detected in the town of Okuma about 1.7 km away from the plant’s front gate, a Kanazawa University researcher said Sunday.
It is the first time plutonium ejected by the stricken facility has been found in soil beyond its premises since the March 11 megaquake and tsunami led to a core meltdown there.
Professor Masayoshi Yamamoto of Kanazawa University said the level of plutonium detected in soil in Okuma, Fukushima Prefecture, is lower than the average level observed in Japan after nuclear tests were conducted abroad.
The Education, Culture, Sports, Science and Technology Ministry has found plutonium in soil on the nuke plant’s grounds, but it was believed to have been fallout from bomb tests abroad.
By analyzing the ratio of three types of isotopes in the plutonium, Yamamoto was able to determine that it was emitted by Fukushima No. 1 and not past bomb tests.
The soil samples were collected by a team of researchers from Hokkaido University before April 22.