In order to assess the distribution of radionuclides around the tailings of CBPP (Coal Burning Power Plants), to assess their dispersion and migration to the environment (food, water and houses), the following parameters are studied by using appropriate techniques.

1. Total gamma dose rate mapping
In a first approach; in order to determine the distribution of radionuclides around the tailings, detailed dose rate mapping is performed using portable gamma counters. Preferably, point measurements are made on a regular grid, and integrated into an interpolated total gamma dose rate distribution map. Depending on the investigated area, the grid density is between 10 and 100 meter.

2. Radionuclides in soil, coal, ash, biota and water
Soil samples at a depth of about 15-20 cm are collected for the analysis of the radionuclide content. Soil sampling is performed according the IAEA procedure (homogenisation of 5 samples and sieved at 2 mm). Natural radionuclides in soil samples are analysed by using about 100 grams of each (homogenized) sample that was dried at 80°C to 105 °C up to constant weight and sealed in a gas-tight container for 25 days. U-238, Th-232, Ra-226, and K-40 specific activity are then determined by means of gamma spectrometry.

3. Radon exhalation
Radon flux at the ground surface is performed by installing flux boxes (with known dimensions and only open at their bottom) at the sample site, and by registering the radon flux by absorption on activated charcoal (giving an integrated value) or by grab-sampling of collected soil-gas and subsequent analysis by the scintillation method (giving instant results).

4. Indoor and outdoor radon
Passive alpha-track-etch detectors are used for indoor radon measurements. Exposure during the cold season for a period of three months in the inhabited room the closest to the surface is the best compromise to assess effective dose risk for the population concerned. Alternatively, charcoal canisters with subsequent gamma-spectrometry are used.

5. Radon in soil
Soil-gas containing radon is sampled trough a steel probe at a depth between 40 and 90 cm and analysed by the scintillation method. If possible, soil permeability is measured at the sample location.