METHODS OF SIMULATING THE FLOW OF A FLUID IN A NUCLEAR REACTOR TANK AND CALCULATING THE MECHANICAL DEFORMATION OF ASSEMBLIES OF A NUCLEAR REACTOR HEART, AND ASSOCIATED COMPUTER PROGRAM PRODUCTS

摘要

This simulation process simulates the flow of a fluid inside a nuclear reactor vessel. The reactor comprises a core disposed within said vessel with fluid inlet and outlet ports, the core having a bottom plate, a top plate, and fuel assemblies extending in an axial direction between plates, the core having a volume defined axially by first and second interfaces corresponding to said plates. The method comprises calculating (120, 130), for the core volume, the pressure (P) and the velocity (V) of the fluid, from an initial value of the velocity or pressure in the first interface and respectively at the second interface, and using balance equations of mass, momentum and energy. The method comprises determining (100) an additional volume inside the tank, the additional volume being external to the volume of the core and axially at one end thereof, the additional volume being axially delimited by two interfaces, one of which is the first or second interface, and the calculation (110, 140), for the additional volume and using said equations, pressure and velocity, from an initial value of the velocity or pressure in each of the interfaces of the additional volume. The calculation of pressure and velocity is first performed for a first volume among the additional volumes and the core, and in the common interface to the additional volumes and the core, then the calculation of pressure and velocity is performed for the second volume among said volumes, the initial value of the speed or pressure at said common interface and for the second volume being the value of the magnitude among the speed and the pressure calculated at said interface for the first volume.