Transfer of radionuclides and stable elements to insects and amphibians in a uranium mill tailings pond in Japan

Sakoda, Akihiro   ; Ishimori, Yuu  ; Murakami, Shoichi*; Horai, Sawako*

One of major uranium mines in Japan was located in Ningyo-toge, Okayama. Uranium mining and test milling were made here in the past, and then there has been a uranium mill tailings pond in Ningyo-toge Environmental Engineering Center, Japan Atomic Energy Agency. Since spring 2016, we have performed sampling of non-human biota - insects and amphibians (i.e. frog and newt) - as well as water and sediment in the mill tailings and other two locations (for comparison) to better understand the transfer of elements in such ecosystem. Concentrations of radionuclides and stable elements in the samples were measured mostly by ICP-MS and -ray spectrometry using a high-purity germanium detector. All samples of sediment, water and organism were found to include more U-238 in the mill tailings pond than those in other two locations. Detailed data will be shown and discussed in terms of the transfer in the environment at the presentation.