Keywords: thermal-fluid systems, system CFD, PBMR, Flownex, thermal conduction network, topology, gas cooled reactor, core modelling, pebble bed modular reactor, computational fluid dynamics, nuclear reactors, nuclear power, nuclear energy, simulation
The system CFD approach applied to a pebble bed reactor core
The system CFD code Flownex is used to simulate the transient behaviour of complete thermal-fluid systems such as the Pebble Bed Modular Reactor. In the context of this system simulation, the complexities in modelling the reactor heat transfer is discussed, as well as appropriate methods of dealing with it. The versatility of the system CFD approach is illustrated with three possible topologies for the pebble bed reactor core model. It is shown that the current pebble bed network topology compares very well to other possible network topologies, while having the advantage of predicting the maximum fuel temperature.