Antinuclear

Published on 22 August 2016

Abstract

The Fukushima Daiichi nuclear power reactor units that generated large amounts of airborne discharges during the period of March 12–21, 2011 were identified individually by analyzing the combination of measured ¹³⁴Cs/¹³⁷Cs depositions on ground surfaces and atmospheric transport and deposition simulations. Because the values of ¹³⁴Cs/¹³⁷Cs are different in reactor units owing to fuel burnup differences, the ¹³⁴Cs/¹³⁷Cs ratio measured in the environment was used to determine which reactor unit ultimately contaminated a specific area. Atmospheric dispersion model simulations were used for predicting specific areas contaminated by each dominant release. Finally, by comparing the results from both sources, the specific reactor units that yielded the most dominant atmospheric release quantities could be determined. The major source reactor units were Unit 1 in the afternoon of March 12, 2011, Unit 2 during the period from the…