Design and Optimisation of an innovative process for CO2 capture
A 2023 survey found that two-thirds of the young French adults take into account the climate impact of companies’ emissions when looking for a job. But why stop there when you could actually pick a job whose goal is to reduce such impacts? The Laboratory for Process Simulation and System analysis invites you to pursue a PhD aiming at designing and optimizing a process for CO2 capture from industrial waste gas. One of the key novelties of this project consists in using a set of operating conditions for the process that is different from those commonly used by industries. We believe that under such conditions the process requires less energy to operate. Further, another innovation aspect is the possibility of thermal coupling with an industrial facility.
The research will be carried out in collaboration with CEA Saclay and the Laboratory of Chemical Engineering (LGC) in Toulouse. First, a numerical study via simulations will be conducted, using a process simulation software (ProSIM). Afterwards, the student will explore and propose different options to minimize process energy consumption. Simulation results will be validated experimentally at the LGC, where he will be responsible for devising and running experiments to gather data for the absorption and desorption steps.
If you are passionate about Process Engineering and want to pursue a scientifically stimulating PhD, do apply and join our team!
Understanding the mechanisms of oxidative dissolution of (U,Pu)O2 in the presence of Ag(II) generated by ozonation
The recycling of plutonium contained in MOx fuels, composed of mixed uranium and plutonium oxides (U,Pu)O2, relies on a key step: the complete dissolution of plutonium dioxide (PuO2). However, PuO2 is known to dissolve only with great difficulty in the concentrated nitric acid used in industrial processes. The addition of a strongly oxidizing species such as silver(II) significantly enhances this dissolution step—this is the principle of oxidative dissolution. Ozone (O3) is used to continuously regenerate the Ag(II) oxidant in solution.
Although this process has demonstrated its efficiency, the mechanisms involved remain poorly understood and scarcely documented. A deeper understanding of these mechanisms is essential for any potential industrial implementation.
The aim of this PhD work is to gain insight into the interaction mechanisms within the HNO3/Ag/O3/(U,Pu)O2 system. The research will be based on a parametric experimental study of increasing complexity. First, the mechanisms of generation and consumption of Ag(II) will be investigated in the simpler HNO3/Ag/O3 system. In a second phase, the influence of various parameters on the oxidative dissolution of (U,Pu)O2 will be examined. The results will lead to the development of a kinetic model describing the dissolution process as a function of the studied parameters.
At the end of this PhD, the candidate—preferably with a background in physical chemistry—will have acquired advanced expertise in experimental techniques and kinetic modeling, providing a strong foundation for a career in academic research or industrial R&D, both within and beyond the nuclear sector.
Monitoring and modeling the evolution of microstructural properties during the fabrication of MOX fuel
The nuclear fuel MOX (Mixed OXide), a ceramic obtained from a mixture of uranium and plutonium oxides, represents a strategic alternative for the valorization of plutonium resulting from the reprocessing of spent fuel. MOX pellets are produced industrially using a powder metallurgy process combined with material densification through high-temperature sintering. The rejected products are reintroduced into the process in the form of "chamotte" powder. Yet, the influence of the content and nature of this chamotte on the microstructural stability of the material remains poorly understood, particularly during the pressing and sintering stages. This aspect is critical for both the mechanical integrity and the in-reactor behavior of MOX fuels. A better understanding of these phenomena, combined with refined modeling, would make it possible to optimize industrial processes and ultimately improve the reliability of these fuels.
The objective of this PhD project is to study and model the evolution of the microstructural properties of MOX fuel as a function of the proportion and nature of the chamotte added during fabrication. The thesis strategy will rely on an integrated approach combining experimental studies with numerical simulations. It will be based on multi-scale characterization of the microstructure, coupling imaging and spectroscopy techniques, as well as on the three-dimensional reconstruction of the microstructure from experimental 2D images. The ultimate goal is to establish a link between the elastic properties of the material and its microstructure. This work will build on a combined experimental and modeling approach, bringing together the expertise of the supervisory team for experiments on plutonium-bearing materials, and for numerical modeling (micromechanical modeling, FFT-based calculations).
At the end of this PhD, the graduate student, with initial training in the physical chemistry of materials, will master a wide range of experimental techniques as well as advanced numerical modeling methods applied to ceramic materials. These skills will open up many job opportunities in academic research or industrial R&D, both within and outside the nuclear sector.
Development of functionalized supports for the decontamination of complex surfaces contaminated by chemical agents
In the case of contamination by a toxic chemical agent, treatment begins with rapid emergency decontamination. Those working in the field must take into account the risk of contamination transfer, in particular by wearing suitable protective clothing. These clothing, as well as the small equipment used, must then be decontaminated before considering undressing to avoid self-contamination. The procedure includes a “dry” decontamination phase generally by applying powders (often clays) which are then wiped off using a glove or sponge. However, this device does not neutralize chemical contaminants and the powder re-aerosolizes easily, so its use is limited to unconfined and ventilated environments. The objective of this thesis is to develop an alternative technology for the decontamination of complex surfaces (clothing, small equipment). We propose to study the functionalization of different supports (such as gloves, wipes, microfibers, sponges, hydrogels, etc.) by adsorbent particles (zeolites, ceramic oxides, MOFs, etc.). A preliminary bibliographic study will allow us to select the most suitable adsorbents and supports for the capture of model chemical agents. The work will focus on the preparation of the supports, and different ways of incorporation of the particles in/on these supports will be compared. The materials will be characterized (incorporation rate, homogeneity, mechanical strength, non-reaerosolization, etc.), then their transfer, sorption and inactivation properties will be evaluated with model molecules.
This subject is aimed at dynamic chemists, motivated by the multidisciplinarity (chemistry of mineral and/or polymer materials, solid characterization and analytical chemistry), and having a particular interest in the development of experimental devices. The candidate will work within the Supercritical Processes and Decontamination Laboratory at the Marcoule site, and will benefit from the laboratory's expertise in decontamination and the development of adsorbent materials, as well as the support and expertise of the ICGM institut in Montpellier on functional polymers and hydrogels. The student will interact with the laboratory's technicians, engineers, doctoral students and post-doctoral fellows. The doctoral student will be involved in the different stages of the project, the reporting and publication of its results, and the presentation of its work in conferences. He/She will develop solid knowledge in the fields of nuclear and environmental science, as well as in project management.
Physico-chemical coupling between a bubbles population and the oxido-reduction of glass-forming liquid
The calcination-vitrification process is the solution used in France for more than 30 years for the conditioning of high-level nuclear waste resulting from the reprocessing of spent fuel. During the vitrification process, the waste is incorporated into a borosilicate glass-forming liquid at more than 1000°C. The glass-forming liquid is homogenized in temperature and composition by stirring and gas bubbling. The incorporation of waste into glass-forming liquid can also lead to gas releases, including those of oxygen resulting from redox reactions between species dissolved in the liquid. It is important to properly control the impact of these gases on the glass and the process.
The redox state of glass-forming liquid at equilibrium between the dissolved species has been the subject of various studies at the CEA in the context of the vitrification of nuclear waste. On the other hand, few studies have been devoted to the kinetics of gas reactions in glass-forming liquid. The objective of this thesis aims to study and model the impact of gas bubbles, whatever their nature, on the redox of melting and the kinetics of associated reactions. An approach combining experimentation and digital modeling will be adopted.
The desired candidate will have a taste for experimentation, characterization and interpretation of results addressing different scientific fields (physico-chemistry of materials, electrochemistry). All experiments will be carried out on non-radioactive elements and will involve processing by digital modeling. This PhD thesis will allow acquiring valuable professional experience in the glass and nuclear industry.
Development of machine learning algorithms to improve image acquisition and processing in radiological imaging
The Nuclear Measurements Laboratory at the LNPA (Laboratory for the Study of Digital Technologies and Advanced Processes) in Marcoule consists of a team specializing in nuclear measurements in the field. Its activities are divided between developing measurement systems and providing technical expertise to CEA facilities and external partners (ORANO, EDF, IAEA).
The LNPA has been developing and using radiological imagers (gamma and alpha) for several years. Some of the developments have resulted in industrial products, while other imagers are still being developed and improved. Alpha imaging, in particular, is a process that allows alpha contamination zones to be detected remotely. Locating the alpha source is an important step in glove boxes, whether for a cleanup and dismantling project, for maintenance during operation, or for the radiation protection of workers. The alpha camera is the tool that makes alpha mapping accessible remotely and from outside glove boxes.
The objective of the thesis is to develop and implement mathematical prediction and denoising solutions to improve the acquisition and post-processing of radiological images, and in particular alpha camera images.
Two main areas of research will be explored in depth:
- The development of real-time or post-processing image denoising algorithms
- The development of predictive algorithms to generate high-statistics images based on samples of real images.
To do this, an experimental and simulation database will be established to feed the AI algorithms.
These two areas of research will be brought to fruition through the creation of a prototype imager incorporating machine learning capabilities and an image acquisition and processing interface, which will be used in an experimental implementation.
Through this thesis, students will gain solid knowledge of nuclear measurements, radiation/matter interaction, and scientific image processing, and will develop a clear understanding of radiological requirements in the context of remediation/decommissioning projects.
Physicochemical Properties of Antimony-containing Photovoltaic (PV) Glass
The proposed PhD thesis is part of the ANR GRISBI project (2026–2030), which aims to optimize the recycling of glass from photovoltaic (PV) panels. These glasses, predominantly manufactured in China, are doped with antimony oxide (Sb2O3) to ensure high transparency while keeping production costs low. However, the presence of antimony currently prevents the recycling of these glasses within the European flat glass industry, which would otherwise greatly benefit from this secondary raw material to reduce its environmental footprint — particularly its greenhouse gas emissions, in line with the carbon neutrality targets set by the Paris Agreement (2015). To make the recycling of PV glass into flat glass production feasible, it is therefore essential to gain a deeper understanding of the physicochemical behavior of antimony in glass, and more generally, within the float process, which involves a hot glass / liquid tin interface.
The core scientific objective of the PhD is to determine the redox equilibria between the multivalent species present in PV glasses, in particular the Sb2O3/Sb and Fe2O3/FeO couples. The work will involve preparing glasses with different Sb2O3 contents, then determining the mechanisms of antimony incorporation into the glass structure, as well as the temperature and oxygen partial pressure (pO2) conditions leading to the reduction of Sb³? to metallic Sb°. Experimental results, based on advanced materials characterizations such as SEM, XRD, EXAFS, and XANES, will be used to enrich thermodynamic databases and to develop a methodology enabling the recycling of Sb-doped PV glasses in flat glass production.
The PhD will be conducted at CEA Marcoule, in collaboration with IMPMC (Sorbonne Université) — two laboratories internationally recognized for their expertise in glass science. All glass samples will be synthesized by the PhD student, and their characterization will primarily rely on facilities available at CEA and IMPMC.
A background in Materials Science is required. This research project will provide the PhD candidate with the opportunity to develop strong expertise in applied glass science and industrial recycling technologies.
Multi-criteria Navigation of a Mobile Agent applied to nuclear investigation robotics
Mobile robots are increasingly deployed in hazardous or inaccessible environments to perform inspection, intervention, and data collection tasks. However, navigating such environments is far more complex than simple obstacle avoidance: robots must also deal with communication blackouts, contamination risks, limited onboard energy, and incomplete or evolving maps. A previous PhD project (2023–2026) introduced a multi-criteria navigation framework based on layered environmental mapping and weighted decision aggregation, demonstrating its feasibility in simulated, static scenarios.
The proposed thesis aims to extend this approach to dynamic and partially unknown environments, enabling real-time adaptive decision-making. The work will rely on tools from mobile robotics, data fusion, and autonomous planning, supported by experimental facilities that allow realistic validation. The objective is to bring navigation strategies closer to real operational conditions encountered in nuclear dismantling sites and other industrial environments where human intervention is risky. The doctoral candidate will benefit from an active research environment, multidisciplinary collaborations, and strong career opportunities in autonomous robotics and safety-critical intervention systems.
Origins and consequences of the heterogeneous alteration of nuclear glasses
This PhD project focuses on the long-term behavior of nuclear glasses used to confine long-lived radioactive waste.
In aqueous environments, these glasses generally undergo homogeneous alteration: the transformation into alteration products occurs at a uniform rate across the entire surface.
However, cases of heterogeneous alteration also exist, where the glass/gel interface becomes irregular, forming pits or cavities.
Two key questions arise: what are the mechanisms responsible for that behavior, and what are the consequences for the long-term durability of the glass?
Several hypotheses have been suggested in the literature, such as local fluctuations in solution composition or mechanical stress at the glass surface, but no definitive explanation has yet been established.
The proposed approach combines accelerated experiments with chemical, mechanical, and structural characterizations, as well as modeling (e.g., mesoscopic and Monte Carlo models).
Experiments will be conducted on glasses with various surface states (polished, irradiated, fractured, etc.) using analytical tools such as SEM, TEM, and nanoSIMS.
Once the mechanisms are identified, the long-term impact of these heterogeneous alteration patterns can be assessed.
The project seeks candidates with a background in chemistry or materials science, strong interest in modeling, and solid theoretical knowledge.
Microemulsion model: Towards the prediction of liquid-liquid extraction processes
This multi-scale modeling PhD project aims to develop innovative theoretical approaches and numerical tools to predict the extraction processes of strategic metals, which are essential for the energy transition. Among the existing methods, liquid-liquid extraction is a key process, but its underlying mechanisms remain poorly understood. To address these challenges, the solvent phases will be represented as microemulsions through a synergy of mesoscopic and molecular modeling approaches.
The mesoscopic approach will involve the development of a code based on microemulsion theory using a random wavelet basis. This code will enable the characterization of the structural and thermodynamic properties of the solutions. The molecular approach will rely on classical molecular dynamics simulations to evaluate the curvature properties of the extractants, which are essential for bridging the two scales.
The new high-performance computational code may integrate artificial intelligence techniques to accelerate the minimization of the system’s free energy while accounting for all chemical species present with a minimal number of parameters. This will pave the way for new research directions, such as predicting speciation and calculating thermodynamic instabilities in ternary phase diagrams, thereby identifying unexplored experimental conditions.
This PhD thesis, conducted at the Mesoscopic Modeling and Theoretical Chemistry Laboratory at the Marcoule Institute for Separation Chemistry, will have applications in the recycling domain and extend to the broader field of nanoscience, thereby expanding the impact of this work.
The PhD candidate, with a background in physical chemistry, theoretical chemistry, or physics and a strong interest in programming, will be encouraged to disseminate their scientific results through publications and presentations at national and international conferences. By the end of the thesis, the candidate will have acquired a broad range of skills in theoretical chemistry, modeling, numerical computation, and physical chemistry, providing numerous career opportunities in both academic research and industrial R&D.