Why Radioactive Cesium?
ＱWhy Radioactive Cesium?
ＡBy Fukushima-Daiichi Nuclear Power Plant Accident, radionuclides generated in the reactor were released into wide environment around Fukushima prefecture, and large amount of radionuclides are still remained.
To understand the relative importance of each radionuclide on exposure, exposure dose were estimated under the extreme condition that people stands 50 years on maximum deposition point, which method is suggested by International Atomic Energy Agency, IAEA.
As a result, 137Cs and 134Cs in several isotopes of cesium were estimated to contribute exposure dose more than other radionuclides, because they have relatively long half-life and high concentration.
And also it was suggested that targeting these radionuclides are suitable for assessment of exposure dose and countermeasures of decontamination.
Under these circumstances, the environmental dynamics research by JAEA targets 137Cs and 134Cs.
|Estimated cumulative effective dose in 50 years(mSv)|
|239Pu + 240Pu||2.411×104 y||15.0||0.12|
※1：Radioactivity is corrected for their decay as of June 14, 2011.
Some elements has several mass number because of the number of neutron. They are called "isotope" and distinguished by the appended number which shows their mass number, i.e., 137Cs and 134Cs.
- Where were radioactive materials deposited and in what quantities?
- What kinds of radioactive materials were released into the atmosphere and the sea and how much?
- How has the distribution of radioactive material been investigated?
- How is the concentration of radioactive Cs measured?
- In what ways does exposure to radiation occur the environment? What kinds of radiation exposures are important in Fukushima?