Upper core supporting structure for nuclear reactor with coolant flow stabilizing facility

摘要

In some nuclear reactors, outlet nozzles (12) are disposed in a pair adjacent to each other due to restrictions imposed by particular configurations of a primary coolant loop and demands for reductions in diameter of a containment vessel. In such reactors, streams of the coolant flowing toward the individual outlet nozzles (12) within a top nozzle become complicated and unstable. An improved reactor core supporting structure is provided which is capable of stabilizing the coolant flow in a region near to the outlet nozzles to thereby ensure temperature measurement of the coolant flowing through an outlet piping with enhanced accuracy and reliability. The structure is disposed within a upper plenum (40) which is defined above a reactor core and hydraulically communicated with a plurality of outlet nozzles (12) installed on a side wall of a nuclear reactor vessel (10) and includes at least a flow stabilizing member disposed at a location close to the outlet nozzle (12) or disposed in a region between the adjacent outlet nozzles (12).