The present research project consists of a multidisciplinary study aimed to optimize a set of geological investigation methods for the assessment of the safety of sites for operation such as radioactive waste repositories, with high potential for environmental hazard.
The studies are based on the integration of sampling and analyses of soil gases with other investigation techniques. Previous soil gas surveys have demonstrated that the soil gas method has great potential for tracing buried faults and fractures in clayey terrains and has a great flexibility. It is possible in fact to carry out surveys along profiles and/or according regular grids at different scales, i.e. with sampling densities in the range of one to a hundred samples per square kilometre.
The main objectives of the research are:
- the implementation of the analytical and sampling techniques in the soil gas method;
- the study of soil gases as fault tracers and of gas migration within soil and fractured zones by means of in situ tests;
- the comparison (and calibration) of the soil gas approach with other methods in order to test both the soil gas method and different lithotypes as natural barriers to gas migration;
- the creation of a data base in order to give mathematical models on gas generation and migration.
The present work has been subdivided into seven tasks:
Task 1: Selecting areas in Italian subsiding sedimentary basins at test sites for the soil-gas and geophysical survey. Laboratory equipments testing and setting up.
Task 2: Sampling and analysis of soil gas.
Task 3: Comparison between soil gas data.
Task 4: Study of soil gas variations with depth, using shallow boreholes ranging from 5 to 10 meters.
Task 5: Execution of in situ tests by injection of gases into the soil and subsequent sampling and analysis.
Task 6: Geomorphological and structural research as support to the study of fracture and fault systems. Geophysical, geotechnical and pedological studies in order to identify the main geological features and to characterize the soil and subsoil of the study areas.
Task 7: Statistical and mathematical analysis of the distribution of soil gases upon the data collected in the surveys.
Funding SchemeCSC - Cost-sharing contracts