Geostatistics perspectives for sampling optimization during radiological characterization - 000003

The objective of radiological characterization is to find a suitable balance between gathering data (con-strained by cost, deadlines, accessibility or radiation) and managing the issues (waste volumes, levels of activity or exposure). The geostatistical approach, which provides consistent estimates and reliable maps, is an appropriate solution for data analysis. This paper deals with feedback experience over years in the use of geo-statistics and sampling optimization for the radiological characterization of various media (soils, concrete structures, process equipment, groundwater...), various activity levels (clearance, low and intermediate, high), and various sizes from very small areas (a few m² or a few m³) to very large sites (at a country scale in post-accidental context). Geo-statistics assumes spatial continuity for radioactive contamination. The variogram, which is based on data, allows the interpretation and modelling of the spatial continuity of the phenomenon. This spatial structure is crucial for the overall geostatistical approach and strongly impact sampling strategies.