Application of CFD Modelling to External Nuclear Reactor Vessel Cooling

In nuclear power plants, passive cooling can increase the safety of reactors whilst reducing costs and design complexity. However, the effectiveness of passive mechanisms needs to be carefully proved with reliable computational modelling. This work focuses on assessing the external reactor vessel cooling (ERVC) strategy by means of computational fluid dynamics (CFD). The accuracy of a two-fluid Eulerian-Eulerian CFD model with boiling capabilities is first assessed, as subsequently is its ability to predict ERVC. The CFD model described proves to be a valuable tool for predicting passive cooling by detecting local boiling incipience and providing three-dimensional vessel temperature distributions, as well as thermal stratification and velocity field predictions in the cooling pool. This work is part of a larger programme aimed at assessing CFD capabilities for predicting passive cooling strategies, with a quantitative assessment of ERVC currently ongoing.