Pre-operational monitoring plan for LIL waste disposal at Saligny

Developed under the PN II Project 71-009 - MONA, the pre-operational monitoring program of the LIL waste disposal site presented in this paper covers the main elements requested for a continuous improvement of site characterization and safety assessment, as well as for the set up of the baseline data requested for the future operational and post-operational monitoring and surveillance. These elements are: vadose and saturated zones hydrogeology, surface erosion, meteorology and radionuclides content in waters, soil and biota. Pairs of TDR (Time Domain Reflectometry) and pressure sensors, coupled with a meteorological station have been installed on site for the continuously measurement of the water content and matric potential changes due to the climate variations. The data will be used to follow the water balance, the pores water velocity and to calculate the infiltration rate. A new set of erosion rates experimentally determined by Pinhole test on surface soil samples improves the knowledge and predictions on the long-time stability of the site. The radiological monitoring started during this project with measurements of radionuclide concentration in surface and underground waters, soil, spontaneous vegetation, milk and cheese from this zone, provides the current level of the radioactivity of the disposal area. The sampling/measurement locations have been selected according to the current knowledge of the Saligny site, and are based on the site models and uncertainty analysis developed under the project. The paper presents the reasons justifying the monitoring locations, frequency and methods used. (authors)