Efficient in situ method to determine radionuclide concentration in soil

A simple realisation of the so-called peak-to-valley method is described combining simulations of photon transport in soil with measured detector properties. Comparisons regarding the total activity of 137Cs determined from γ spectra recorded in situ to results from soil sampling show excellent agreement for six different sites in Sweden with different surface properties and activities ranging from 15 to 1000 kBq/m2. These results are quite insensitive to assumptions regarding soil composition. Our results for the burial depth are more sensitive to assumptions regarding soil composition, however, still in general agreement with the results from the soil samples.