Study of aerosol transport through degraded materials

Radioactive Waste (RW) are produced during nuclear activities and are categorized as a function of their activities and their half-life in order to manage their conditioning, transport, storage… Mortar can be used in order to immobilize and/or create a safe barrier forming a Radioactive Waste Package (RWP) in order to protect the environment. It is important to study the efficiency of this mortar barrier for long term and safety assessment have to investigate the case of crack mortar formation as radioactive particles could then migrate in the cracks.
The LECD laboratory investigated this problematic by measuring the migration of CeO2 particle in mortar cracks using X-Ray microtomography. The cracks were synthesized by dissolving plastic molds (designed by 3D printing). This study showed the influence of particle interactions with tortuosity and roughness of the crack, but was limited to 40 µm particle diameter.
The aim of the postdoctoral work is to develop an experimental approach similar to the method developed to study the efficiency of HEPA filters, with particles of 0.05 - 5 µm diameter. Quantitative measurements will be performed on the particle flows on both sides of the cracked mortar sample. LECD has acquired an aerosol generator, a light-scattering aerosol spectrometer system for particle size analysis and concentration determination and an Universal Scanning Mobility Particle Sizers. The researcher will also develop modelling work using numerical tools as STARCCM+.
This project will be carried out under the format of an 12-month fixed-term contract at the Atomic Energy and Alternative Energies Commission (CEA), at the Cadarache site (Saint-Paul-lez-Durance, 13) at the Expertise and Destructive Characterization Laboratory (LECD) of the Expertise and Characterization CHICADE Service (SECC).
Contacts: ingmar.pointeau@cea.fr (R&D engineer) – Olivier.vigneau@cea.fr (Head of the Laboratory)

Development of processing by Artificial Intelligence of a measuring and forecasting station

This post-doctoral proposal is part of the French atomic commission (CEA) project "MultiMod'Air", which involves developing an « intelligent » prototype of air quality measurement and forecasting station within two years. The work proposal is to develop the bricks of Artificial Intelligence (AI) of the project: correction by ANN (Artificial Neuronal network) of the measurements obtained through low cost sensors, correction ANN of weather forecasts at the station level, which are simple treatments to implement. The actual research work will concern the development of a AI based pollution forecast at the station by learning from past events.