235U/238U Isotopic ratio in plant samples from Fukushima Prefecture

Uranium was recovered from plant samples obtained from Fukushima Prefecture, and the U-235/U-238 isotopic ratio was analyzed using thermal ionization mass spectrometry. The possibility of soil and biosphere contamination with U by the nuclear accident at Fukushima Daiichi nuclear power plant was evaluated. The isotopic ratio of U in the plant samples was the same as the natural abundance, which suggests that no significant contamination with U occurred.