Apparatus and methods for protecting a jet pump nozzle assembly and inlet-mixer

摘要

A jet pump (18) for a nuclear reactor includes a riser (20) and an inlet mixer (23) having a plurality of nozzles (24) and a mixing section (25) for receiving coolant flow from the nozzles and suction flow from an annular space (16) between the reactor vessel (10) and the shroud core (14). To minimize or eliminate electrostatic deposition of charged particulates carried by the coolant on interior wall surface of the inlet-mixer of the jet pump, and also to inhibit stress corrosion cracking, the interior wall surfaces of the nozzles and mixing section are coated with a ceramic oxide (31) such as SiO2 and Ta2O5 to thicknesses of about 0.5-1.5 microns.