Three-dimensional hydrodynamic modeling of the second shutdown system of an experimental nuclear reactor

A three-dimensional (3D) computational fluid dynamics (CFD) model is presented for the Second Shutdown System (SSS) of the experimental nuclear reactor RA-10 under design and construction by the Argentinian National Commission of Atomic Energy (CNEA). The RA-10 SSS consists on the drainage of the reflector tank surrounding the reactor core through a system of pipes in a limited amount of time solely by the action of gravity. The CFD model focuses on the 3D modeling of the reflector tank hydrodynamics and links the effects of the draining piping system through dynamics boundary conditions. The CFD model is first applied to a similar system, the RA-10 SSS Mockup, for which experimental data is available. Reasonable agreement is observed between the CFD model and the experimental observations for the RA-10 SSS Mockup. Finally, the validated CFD model is applied to the RA-10 SSS. The model results show that the performance of the RA-10 SSS meets the design requirements.