Large-scale depletion calculations with Monte Carlo neutron transport code H/F - Gif-sur-Yvette, France - CEA Tech

Description

Description du poste

Domaine

Neutronique et physique des réacteurs

Contrat

Post-doctorat

Intitulé de l'offre

Large-scale depletion calculations with Monte Carlo neutron transport code H/F

Sujet de stage

One of the main goals of modern reactor physics is to perform accurate and
detailed multi-physics simulations of the behaviour of a nuclear reactor core.
Multi-physics calculations in nominal conditions imply a coupling between a
transport equation solver for the neutron and precursor populations, thermal
and thermal-hydraulics solvers, and a depletion solver. Such calculations still
represent a steep challenge from many points of view. Monte Carlo simulations
are the golden standard for neutron transport simulations, due to their exact
treatment of the energy variable in the Boltzmann equation. In , CEA
performed a preliminary demonstration of Monte Carlo burnup calculation on a
full-scale PWR reactor core, without thermal-hydraulic feedback, using the
Monte Carlo neutron transport mini-app PATMOS and the depletion code MENDEL.
Later, in , we performed a multi-physics simulation of a full PWR using
PATMOS and the THEDI thermal-hydraulics solver.

Durée du contrat (en mois)

12

Description de l'offre

The next step towards high-fidelity full-scale core calculations is to
integrate neutron burnup calculations with thermal-hydraulic feedback.
Achieving this result is the main goal of this post-doctoral position. The
proposed work is divided into two parts. First, the candidate will revisit and
extend the existing neutronics/depletion and neutronics/thermal-hydraulics
couplings in order to perform a fully-coupled
neutronics/thermal-hydraulics/depletion multi-physics calculation. The C3PO
(Collaborative Code Coupling Platform) code coupling platform will be used to
this effect. The target use case for the feasibility demonstration will be a
full-scale PWR reactor core with a number of depleted materials of the order of
several millions. Second, a study will be performed to evaluate the behavior,
performance, and stability of the coupled simulation. The emphasis will be
placed on the consequences of using a Monte Carlo solver for neutronics, which
enables high-fidelity simulations but by nature carries uncertainties and
statistical fluctuations on the estimated physical observables. Performance and
scalability tests will also be perfomed on the size of the reactor core, the
number of available CPU cores, and the number of depleted regions.

The work plan is the following:
- Study the bibliography of the state-of-the-art code-coupling schemes and
tools in neutronics, thermal-hydraulics and depletion physics;
- Acquire hands-on knowledge of the PATMOS code and existing PATMOS/MENDEL et
PATMOS/THEDI multi-physics couplings. Contribute to the verification and
analysis of these couplings;
- Develop a neutronics/thermal-hydraulics/depletion coupling using the C3PO
tool. Demonstrate the coupling on a set of full-scale PWR reactor core
simulations;
- Analyze the behavior of the proposed coupling schemes, study their
performance and scalability, with a focus on the impact of the Monte Carlo
neutronics solver on the results.
The candidate will be based in Saclay, in the Paris region, and will integrate
into the development team of TRIPOLI-5. TRIPOLI-5 is a next-generation Monte
Carlo particle transport code, developed at CEA and IRSN scientists since .

The proposed duration of the initial contract is 12 months.

Moyens / Méthodes / Logiciels

Monte Carlo, TRIPOLI-5, depletion solver, THEDI, theral-hydraulics, multi-physics

Profil du candidat

PhD in nuclear engineering or computer science