Methodologies for measurement of transuranic elements in environmental samples and migration behavior of transuranic elements in paddy fields

Methodologies for the measurement of transuranic elements in environmental samples and migration behavior of transuranic elements in paddy fields are reviewed in this report. Long lived transuranic elements in our environment are quite important, because their effect to human is prolonged. Migration analysis of long lived transuranic elements in paddy fields is also quite important, because rice is our main dishes. For the methodologies about the measurement of transuranic elements in environmental samples, traditional chemical separation and purification plus alpha-ray spectrometric methods are reviewed with mass spectrometric method. For the estimation of migration behavior of transuranic elements in paddy fields, experimental results from 1957y to 1989y in Japan are reviewed. Important findings are as follows. (1) Detection limit of transuranic elements for traditional chemical separation and purification plus alpha-ray spectrometric methods is about 0.2mBq/sample(10,000min counting). On contrast, detection limit of transuranic elements for mass spectrometric methods using High Resolution ICP-MS is 0.02mBq/sample for 237Np. (2) Integrated deposits of 239,240Pu and 137Cs in paddy field soils are 2-3 times higher in Pacific ocean side area than Japan sea side area in Japan. (3) Apparent residence time of 237Np in paddy field soils was estimated to be in the range of 50-70 years, which is shorter than those of 239,240Pu and 137Cs(100-140 years). (author) 54 refs