A generic semi-implicit coupling methodology for use

A generic semi-implicit coupling methodology has been developed and implemented in the RELAP5-3D © computer program. This methodology allows RELAP5-3D © to be used with other computer programs to perform integrated analyses of nuclear power reactor systems and related experimental facilities. The coupling methodology potentially allows different programs to be used to model different portions of the system. The programs are chosen based on their capability to model the phenomena that are important in the simulation in the various portions of the system being considered and may use different numbers of conservation equations to model fluid flow in their respective solution domains. The methodology was demonstrated using a test case in which the test geometry was divided into two parts, each of which was solved as a RELAP5-3D © simulation. This test problem exercised all of the semi-implicit coupling features that were implemented in RELAP5-3D © The results of this verification test case show that the semi-implicit coupling methodology produces the same answer as the simulation of the test system as a single process