Radioactivity and Air Dose Rate
（2018）
ＱHow can the radioactive Cs distribution at the bottom of lakes or rivers be measured?
ＡThe depth distribution of radioactive Cs in bottom materials can be determined based on the characteristics of the γ-ray spectrum measured at the bed. Developed by the Japan Atomic Energy Agency, this method enables a fast and simple understanding of the actual pollution conditions without the need to collect samples, which makes monitoring more efficient.
- The conventional method of collecting bottom-material samples requires approximately one week per reservoir.
- The new method developed by the Japan Atomic Energy Agency takes approximately 1-2 days.
Fig.1 Survey method used to obtain radioactive Cs distribution in bottom materials
(comparison of conventional and new methods)