The activity of selected gamma radionuclides in the Tatra National Park

Cesium is naturally occurring active metal, represented by one stable isotope Cs-133, and number of artificial, unstable, isotopes. The most common artificial isotope of cesium is Cs-137, present in the environment of the Tatra Mountains due to nuclear weapon testing in late '50, and nuclear reactor accident in Chernobyl in 1986. However in recent years the growth in biofuels use for power generation can be the next source of Cs-137 emission. Burning wood cultivated on grounds contaminated by Cs-137 can introduce secondary emission of this isotope to the atmosphere. This paper presents the results of determination of gamma emitting radionuclides artificial Cs-137 and natural K-40 in soil samples from the Tatra Mountains. Results show some differences in the vertical distribution of examined radionuclides. It was found that the change of activity of Cs-137 in the soil samples depends mostly on the soil density and on the concentration of organic material. The state of "zero" Cs-137 activity was developed in the form of maps.