Four-equation multiloop reactor coolant system simulation model

It is generally known that the nuclear power plant simulator is an essential part of operator training. Since the Three Mile Island Unit 2 accident, the general trend has been a gradual upgrading of the training simulators and an evolution of a new generation of simulation models. In order to provide realistic responses for various operating conditions and unanticipated transients of the reactor coolant system (RCS), it is necessary to have a set of dynamic equations that account for the conservation of mass, momentum, energy, phase slip, and nonequilibrium effect of subcooled boiling. The objective of this paper is to present the four-equation drift-flux RCS model REVOT-HKU developed by the Univ. of Hong Kong for pressurized water reactor (PWR) simulators. The HKU four-equation drift-flux RCS model has demonstrated that it is a useful tool with reasonably good fidelity for RCS flow dynamics and void distribution calculations, which can be used for advanced training simulators. With the phase slip and thermal nonequilibrium effects properly taken into account, the present model can be used to accurately determine the void distribution and transport within the RCS and a PWR during anticipated and unanticipated transients