Base Information Q&A SiteJAEA

Radioactivity Dynamics in River System

(2015)

Is there a continuous input of cesium contamination to rivers from forests?

The concentration of radioactive cesium flowing from forests into mountain streams tends to decrease with time.

  • Investigations in Kawamata Town, Fukushima Prefecture have revealed that most radioactive cesium (more than 90%) flowing from forests into mountain streams is adsorbed on suspended materials
  • In all of the rivers investigated, the concentration of radioactive cesium in the dissolved state and that adsorbed on suspended materials or coarse organic matter tends to decrease with time

Time-dependence of radioactive cesium concentrations in three mountain streams in Kawamata Town.

Fig.1 Time-dependence of radioactive cesium concentrations in three mountain streams in Kawamata Town
The upper three figures show 137Cs in the suspended solids (SS) and adsorbed on coarse organic matter.
The lower three figures show cesium in the dissolved state.

Reference: Report on the Project for the Nuclear Regulatory Agency, “Data Accumulation for Distribution of Radioactive Materials Released from Fukushima Daiichi Nuclear Power Station, TEPCO and Development of Migration Model” (FY 2014).