Plutonium detected in soil outside Fukushima nuke plant
OKYO (Kyodo) -- A small amount of plutonium believed to have been emitted from the crippled Fukushima No. 1 nuclear plant has been detected in soil outside the plant, a researcher at a university said Sunday. It is the first time that plutonium believed to have been spewed from the Fukushima plant damaged by the March 11 mega earthquake and tsunami has been detected in soil outside the plant. Masayoshi Yamamoto, professor at Kanazawa University, said, however, the level of the plutonium detected in samples of soil collected in the town of Okuma in Fukushima Prefecture, about 1.7 kilometers from the front gate of the nuclear plant, is lower than the average level of plutonium observed in Japan following past bomb nuclear tests abroad. The Ministry of Education, Culture, Sports, Science and Technology found a small amount of plutonium in soil outside the plant in an earlier survey but the substance was believed to have been emitted in such nuclear bomb tests elsewhere.
The soil samples were collected by a team of researchers of Hokkaido University before April 22. The government designated the town within the 20-kilometer radius from the plant as a ÂŤno-goÂť zone where residents are barred from entry, Yamamoto said.
But by analyzing the proportion of three types of isotopes in the plutonium, Yamamoto determined that the substance was emitted from the crippled Fukushima plant and was not from past nuclear bomb tests elsewhere.