STRESS REDUCER OF INTERNAL PUMP

PROBLEM TO BE SOLVED: To reduce stress generating at the connection part between a pump casing and a pipe. SOLUTION: The pump casing 10 of an internal pump 5 and a pipe 25 attached to the pump casing 10 are fixed and supported with a stress reducing mechanism 26. The stress reducing mechanism 26 is constituted of a pipe support part 27 fixing and supporting the pipe 25, a rig shape holder 28 holding the outside of the pump casing 10 and a connector 29 connecting the pipe support part 27 and the holder 28. When reactor pressure vessel 1 deforms by the effects of high temperature and high pressure and the shift of casing position generates a stress, the stress can be dispersed by the stress reducing mechanism 26 without concentrating to the connection part between the pipe 25 and a nozzle part 23.