The sodium spray fires, generated by a leak in a sodium pipe, are of major concern for the safety of the Sodium Fast Reactors. The main consequences of these fires are the temperature and pressure increase within the involved building or containment as well as the production of a chemical source term that could be released into the environment.
The key phenomenon to consider for spray fire studies is the fragmentation of the liquid sodium jet against an obstacle (room wall or ceiling). This mode of fragmentation has to be carefully assessed with a special focus on the droplet population generated at the impact.
To do so, the LESC lab in Cadarache is currently preparing an experimental loop involving a water jet impacting a horizontal or vertical surface.
The Ph-D work will then consist in:
- Performing the impact experiments with varying jet initial diameter, velocity and orientation;
- Analyzing the images from the high-speed camera with an in-house software and extract the droplet size and velocity distributions;
- Suggesting a model that could represent this mode of fragmentation and the resulting droplet population;
- Implementing this model into the CEA canoP CFD software;
- Validating the developed model against the results from the above image analysis.