Airborne Radionucides onto Pine Needles Collected in the Vicinity of the Nuclear Power Plant

概要

論文の詳細を見る
Contents of ^<137>Cs, ^<54>Mn and ^<60>Co in pine needles were investigated in the vicinity of the nuclear power plant in Tsuruga-shi, Fukui Prefecture. Concentrations of ^<54>Mn and ^<60>Co decreased, independent of the ^<137>Cs level, with the increase of the distance from the plant and showed a similar pattern of distribution to that determined by the Gaussian plume model under the slightly unstable stability condition of the atmosphere. These nuclides were so efficiently retained in pine needles that any of them could not be readily removed by washing with water. The differentiation in retention was supposed to be hardly effected by rainfall and other weathering processes among these nuclides. The retention of radionuclide in pine needles was examined by using the radioactivity ratio of ^<54>Mn to ^<60>Co. The values gradually decreased during the period studied with the rate depending only upon the physical decay constants.
日本放射線影響学会の論文