Evolution of the Thermal hydraulics design methodologies for the European Pressurized Reactor (EPR) Vessel

摘要

The thermal-hydraulic design of the first PWR's was mainly based on an experimental approach, with a large series of test on the main equipment (control rod guide tubes, RPV plenums ...), to check its performances. Development of CFD-codes and computers now allows for complex simulations of hydraulic phenomena. Provided adequate qualification, these numerical tools are efficient means to determine hydraulics in the given design, and to perform sensitivities for optimization of new designs. Experiments always play their role, first for qualification, and for validation at die last stage of the design. The design of the European Pressurized water Reactor (EPR), jointly developed by FRAMATOME-ANP, EDF the German Utilities (GU), is based on both hydraulic calculations and experiments, handled This paper describes the collective effort launched by FRAMATOME-ANP and EDF, on hydraulic calculations for the Reactor Pressure Vessel (RPV) of the EPR reactor. It concerns 3D-calculations of RPV-inlet including cold legs, RPV-downcomer and lower plenum, RPV-upper plenum up to and including hot legs. It covers normal operating conditions, but also accidental conditions as PTS (Pressurized Thermal Shock) in small break loss of coolant accident (SB-LOCA). Those hydraulic studies have provided numerous useful information for the mechanical design of RPV-internals.