Abstract
Radon reference sites Cetyně, Bohostice and Buk in the central Bohemia, Czech Republic, were established in the year 2000. Radon reference sites serve for the control of the correct determination of radon activity concentration in soil gas performed by organizations in the Czech Republic.
After fifteen years of radon measurement on radon reference sites was performed their restoration. Radon activity concentration in soil gas, permeability of soil, and uranium concentration were determined on new measurement grid in 2016