沖縄本島における湧水中の天然放射性核種について

概要

論文の詳細を見る
The activities of natural radionuclides, ^<238>U, ^<234>U, ^<226>Ra, ^<228>Ra, ^<222>Rn, ^<210>Pb and ^<210>Po in ground waters collected from Okinawa Island were measured. The ^<234>U/^<238>U activity ratios in most samples showed more or less unity, whereas, relatively high values of 2.0-4.0 were obtained in samples from Motobu area. ^<222>Rn activities in the ground waters were much higher than the other uranium series nuclides. The ^<222>Rn/^<226>Ra activity ratios ranged from 3000 to 29000, and those for ^<210>Po/^<210>Pb were from 0.08 to 0.82. On the whole, activities of the nuclides in the ground waters at the studied points showed higher in the order of ^<222>Rn≫^<210>Pb>^<234>U>^<238>U>^<226>Ra>^<210<Po. In addition to α_recoil dissolution, the selective absorption and/or desorption by some organic or inorganic substances in the aquifer may be happening.
日本地球化学会の論文
1997-12-10