CDD PhD Position in Materials Physical Chemistry (M/F)

Job Description

Thesis Subject

Topic:
Modeling Corrosion Mechanisms of 316L Stainless Steel under Water Radiolysis in Pressurized Water Reactors
This PhD project is part of ongoing efforts to understand the aging mechanisms affecting metallic materials used in pressurized water reactors (PWRs). More specifically, it focuses on modeling the corrosion processes occurring in 316L stainless steel, a structural material widely used in nuclear reactor systems.
During reactor operation, the chemical environment of the primary coolant circuit is continuously modified by water irradiation. This irradiation induces water radiolysis, generating highly reactive chemical species that interact with metallic surfaces, alter passive oxide layers, and accelerate corrosion processes.
The successful candidate will investigate the physical phenomena occurring at the water/steel interface during water radiolysis using two complementary computational approaches.
The first approach involves Monte Carlo simulations using the GEANT4-DNA and GATE codes. GEANT4 will be employed to simulate irradiation conditions based on the geometry of the irradiation cell currently used in the PhD project of B. Lathuillière (MATICE PhD student, 2024–2027). GEANT4-DNA and GATE, specifically designed for radiolysis studies, will be used to determine the nature and energy distribution of radiolytic species generated in water (hydrated electrons, photons, H• radicals, H₂O₂, etc.) under predefined irradiation conditions. These activities will constitute the main objective of the first year of the PhD.
A precise determination of the passive layer thickness is required to accurately assess the transport and interaction of radiolytic species. To address this issue, the second approach will rely on molecular dynamics simulations using the LAMMPS code and ReaxFF empirical potentials, following methodologies similar to those developed by V. Jamebozorgi. Molecular dynamics calculations will be performed under experimentally relevant conditions (temperature, pH, etc.), corresponding to the experimental studies being conducted. These investigations will form the core of the second year of the PhD.
The simulation results obtained from both methodologies will be compared and refined to improve model accuracy. They will also be confronted with experimental data in order to propose one or several mechanistic descriptions of radiolysis-induced corrosion in stainless steels. This work will constitute the primary objective of the third year of the project.
The originality of this research lies in the coupling of two simulation scales with experimental observations currently being acquired in the PhD project of B. Lathuillière. The project is highly interdisciplinary, combining nuclear physics, radiation chemistry of materials, corrosion science, and theoretical modeling.
This work fits within the internationally recognized expertise of the MATICE group in irradiated materials research, which maintains long-standing collaborations with CEA, Framatome, ASNR (LETR), and the Karlsruhe Joint Research Centre (JRC).

Expected Skills and Qualifications
Scientific Background
Applicants should have knowledge in several of the following areas:
• Materials physical chemistry: crystal defects, diffusion processes, irradiation effects, radiolysis.
• Solid-state and surface chemistry: oxidation, corrosion, passivation of stainless steels.
• Nuclear engineering fundamentals: operation of pressurized water reactors, thermo-hydraulic and irradiation environments.
Computational Skills
• Python programming (data analysis and scripting).
• Linux environments and high-performance computing (HPC) systems.
• Simulation data management, post-processing, and visualization.
Transferable Skills
• Scientific writing skills in English (good written and oral proficiency required).
• Ability to work independently and tackle complex scientific problems.
• Strong communication skills and willingness to interact within multidisciplinary collaborations.
• Curiosity and interest in interdisciplinary research.
Previous experience with particle transport simulation codes such as Geant4 and/or multiscale modeling approaches will be considered an asset.

Your Work Environment

The PhD candidate will join the MATICE Group (Materials under Extreme Conditions) at the Lyon Institute of Physics of the Two Infinities (IP2I), a joint research laboratory operated by the CNRS-IN2P3 and Claude Bernard Lyon 1 University.
The MATICE group investigates the evolution of the physicochemical and structural properties of materials used in the nuclear industry under extreme conditions, particularly high temperatures and irradiation environments.
More specifically, this PhD project belongs to the research theme "Radiolysis at Interfaces", currently developed within the MATICE group. The work will be conducted in close interaction with ongoing experimental studies performed as part of the PhD project of B. Lathuillière (2024–2027), supervised by N. Bérerd and N. Moncoffre.
The candidate will benefit from access to state-of-the-art computational resources. At IP2I, dedicated scientific computing infrastructures, including CPU and GPU clusters, HPC facilities, and big-data environments, are available for large-scale simulations and data analysis, together with technical support and training opportunities.
Additional computational resources are available through the Scientific Center for Numerical Modeling (PSMN) at ENS de Lyon, which provides access to clusters comprising several tens of thousands of computing cores within one of France's largest regional mesocenters for scientific computing.
This PhD project is funded within the framework of the French Priority Research Program and Equipment initiative (PEPR) entitled “Fundamental Science for Nuclear Fission” (SCIAM), officially launched on December 1, 2025, and scheduled to run until the end of 2031.
More specifically, the project contributes to Project 4: Fundamental Data for Irradiated Materials and to Work Package 2 (WP2): Interfaces under Irradiation.

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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