Cesium and Strontium Radioactive Contamination (construction)

The Sources of radioactive cesium and strontium

Radionuclides of cesium-137 (Cs-137), cesium-134 (Cs-134) are the substantial part of nuclear fallout from nuclear weapons testing and nuclear reactor accidents. In Europe caesium-134 fallout originates from the Chernobyl accident exclusively, caesium-137 stems partly from Chernobyl and partly from the fallout of atmospheric atomic bomb tests in the 1950s and 1960s. Radioactive strontium-90 (Sr-90) originates from the Chernobyl accident only.

The most efficient deposition of radionuclides in the case of radioactive fallout arise from radioactive rain or snow following nuclear plant accident or weapons testing. As opposed to this so-called wet deposition, dry deposition is much less efficient. Therefore, soil contamination is low in regions which have low precipitation as compared to regions with much rain, even if atmospherical contamination was similar in both regions. The statistical evaluation as a rule shows very good correlation of precipitations and soil contamination.