INTERNAL PUMP AND LIGHT WATER NUCLEAR POWER PLANT PRIMARY SYSTEM PIPING

摘要

PROBLEM TO BE SOLVED: To provide a reliable internal pump and light water nuclear power plant primary system piping by reducing the increase in frictional loss of a flow by the gap part of the internal pump to inhibit of secular change in recirculation system piping and a main steam pipe which occupy the major part of the nuclear power plant primary piping and reduction in radiation exposure, in addition to reduction in abrasive damage of pump parts and inhibition of secular change in pump performance. SOLUTION: The internal pump comprises a pump shaft extending through the lower end plate of a reactor pressure vessel; a pump impeller installed to the tip of the pump shaft on the inside of the reactor pressure vessel to forcedly circulate reactor cooling water in the pressure vessel; a motor part for rotating the pump shaft; and an auxiliary impeller mounted on the pump shaft in a lower portion of the motor part to forcedly circulate cooling water in the motor. A hydrophilic film is provided on the circumferential surface of the pump impeller. COPYRIGHT: (C)2005,JPO&NCIPI