Current practices for assessing the safety of nuclear reactor systems rely on a “divide-and-conquer” strategy, where the different physical phenomena and scales are solved by different solvers. Such approaches allow neither resolving the non-linear coupling terms between the different physical fields, nor the multi-scale phenomena. In the present project, a unified and consistent methodology based on recent advances in numerical methods is proposed. The governing equations describing neutron transport, fluid dynamics, and heat transfer will be solved within the same numerical tool using Jacobian-Free Newton Krylov methods, which are methods particularly well suited to treat strongly coupled non-linear problems involving stiff multiple time-scales. In order to guarantee reasonable computing times, coarse mesh methods will be used. The interdependency between the different scales will be accounted for in an innovative manner. For neutron transport, the nuclear macroscopic cross-sections will be created “on-the-fly” using a fine-mesh neutron transport solver embedded into the coarse-mesh solver. On the thermal-hydraulic side, closure relationships will be provided by subgrid methods. This research program makes use of academic front-end knowledge and expertise. It will tackle the modelling of nuclear systems from an innovative and integrated viewpoint, which will contribute to high-fidelity and reliable safety evaluations of both present and future reactor systems.
- Fraunhofer-Chalmers Centre (Research Institute, Sweden)
The project is closed: 31/12/2016