Abstract
Geostatistics provides innovative tools for the radiological characterization of nuclear facilities under decommissioning as well as contaminated sites for remediation. The relevance of this approach relies on the presence of a spatial continuity for radiological contamination. In this case, geostatistics provides reliable activity estimates, uncertainty quantification and risk analysis, which are essential decision-making tools for decommissioning and dismantling projects of nuclear installations.
Waste characterization is then performed taking all relevant information into account: historical knowledge, surface measurements and samples. Thanks to the multivariate processing, the different investigation stages can be rationalized as regards quantity and positioning.
Waste characterization is finally obtained through the analysis of probability maps of exceeding activity levels. The estimation support must be considered to discriminate punctual issues, such as hot spot identification, and waste production issues on larger areas. The main goal of this data processing remains an easier radiological waste management and the best waste categorization with acceptable investigation costs.
The combination between geostatistics outputs and technical/budget constraints leads to a very visual and helpful decision tool. Following the ALARA principle (As Low As Reasonable Achievable), a balance between removed contamination and related treated volume can be discussed on sound results.
