Research and development of the radiation dose measurement instrument in the sediment of lakes, rivers and sea bed

Yanagizawa, Koichi; Hayashi, Toshio*; Oinuma, Masaru*

The development of instrument aimed at the measurement of radiation dose in the sediment of lakes, rivers and sea bed has been carried out. The radiation level contained in the sediment at the bottom of lake and so on is anticipated to indicate the existence of locally high radiation spots where the diffused radioactive substance is accumulated in ponds, rivers and lakes by rainwater. The radiation dose measurement system developed this time is to measure -ray by dragging the detector, which is called probe, at the bottom of lakes to understand the radiation dose over a wide area. Furthermore, the measurement of resistivity value at the bottom of lakes is simultaneously done to presume the condition of sediment.