General information
Organisation
The French Alternative Energies and Atomic Energy Commission (CEA) is a key player in research, development and innovation in four main areas :
• defence and security,
• nuclear energy (fission and fusion),
• technological research for industry,
• fundamental research in the physical sciences and life sciences.
Drawing on its widely acknowledged expertise, and thanks to its 16000 technicians, engineers, researchers and staff, the CEA actively participates in collaborative projects with a large number of academic and industrial partners.
The CEA is established in ten centers spread throughout France
Reference
SL-DES-24-0150
Thesis topic details
Category
Condensed Matter Physics, chemistry, nanosciences
Thesis topics
Phase field modeling of porosity transport by evaporation and condensation in MOX fuel for Sodium Fast Reactors
Contract
Thèse
Job description
The aim of the proposed thesis is to develop a phase-field model describing the migration of fabrication porosity in uranium-plutonium mixed oxides under irradiation in sodium fast reactors. The model will take into account evaporation and condensation phenomena as the microscopic driving force moving porosity where the necessary local temperature and temperature gradient conditions are reached to establish this transport mechanism. To provide a consistent estimate of the vapor pressure differences governing the rate of evaporation (and condensation), the phase field model will be coupled to a thermodynamic description of the U-Pu-O ternary system. The candidate will work on the development of the theoretical formulation of the phase field model, as well as its inclusion in the framework of a finite element solver. The computational tool will be applied to study the conditions encountered in prototypical fast neutron reactors, in order to derive new pore migration rate laws for inclusion in the scientific fuel behavior calculation tools (OCS) used at industrial level, such as PLEIADES/GERMINAL V3, the OCS developed in the host department at CEA IRESNE.
The results obtained in the thesis will be the subject of presentations at international conferences (e.g. NuMat - The Nuclear Materials Conference, MMM - Multiscale Materials Modeling Conference, MiNES - Materials in Nuclear Energy Systems, CALPHAD), as well as publications in international scientific journals (Computational Material Science, Journal of Nuclear Materials, Journal of Applied Physics, Acta Materialia).
At the IRESNE institute (CEA Cadarache), the candidate will join a multi-disciplinary materials science community (solid state physics, thermics, mechanics, applied mathematics, thermochemistry, thermodynamics) open to both international research and the industrial world, will have the opportunity to interact with experts involved in the various stages of nuclear reactor design, and will use state-of-the-art numerical simulations on both small and large scales. The candidate will have the opportunity to spend part of his thesis in his thesis supervisor's university laboratory at the Ecole Polytechnique, where he/she will be able to complement the experience gained in an applied research institute such as the CEA with the more academic exposure offered by a university institution. Finally, the candidate will have the opportunity to familiarize himself/herself with and become an expert of two of the most widely used techniques for analyzing the evolution of microstructures in many industrial fields: phase field and thermodynamic calculations using the CALPHAD technique.
University / doctoral school
Ecole Doctorale de l’Institut Polytechnique de Paris (IP Paris)
Ecole Polytechnique
Thesis topic location
Site
Cadarache
Requester
Position start date
01/10/2024
Person to be contacted by the applicant
BARANI Tommaso tommaso.barani@cea.fr
CEA
DES/DEC/SESC/LEVA
Centre de Cadarache, Bâtiment 151, 13108 Saint-Paul-lez-Durance
0442252621
Tutor / Responsible thesis director
PLAPP Mathis Mathis.Plapp@polytechnique.fr
Ecole Polytechnique
Laboratoire de Physique de la Matière Condensée
Ecole Polytechnique
91128 Palaiseau cedex, France
01 69 33 47 77
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