Radioactivity and Air Dose Rate
ＱHow can the types of minerals to which radioactive Cs is adhered be analyzed?
ＡMineral types can be identified using an X-ray diffractometer (XRD).
- When a sample that contains crystals in which atoms are aligned is irradiated with X-rays from a particular angle, the X-rays are strongly reflected.
- The angle is determined by the wavelength of the X-ray and the interval between the planes in which atoms are aligned. Therefore, the types of crystals present can be identified by measuring the angle of the strong reflection.
- We used XRD to analyze the mineral composition of deposits from the upper to lower reaches of a river system, as well as to the sea.
- The results showed that, among river system deposits, clay fractions (small grain sizes) in which the radioactive Cs concentration was relatively high contained a lot of clay minerals, such as biotite, which had strongly absorbed radioactive Cs.