Measurements and numerical experiments of radon in earthen materials covering the soil

Sakoda, Akihiro   ; Tanaka, Hiroshi ; Ishimori, Yuu  

Ningyo-toge Environmental Engineering Center made the soil capping at part of the uranium mill tailings pond and then has been accumulating a variety of measurement data for consideration of its effectiveness. We have presented some data on the depth profile of soil radon gas concentrations measured from April to December 2015, at the annual meeting of Japan Health Physics Society in 2016. The soil radon measurement has been performed to now with modification of measurement methods. The present talk reports the results of soil radon measurements for three years (2018 to 2020) and numerical simulations.