Feedwater sparger

Purpose: To suppress the generation of cyclic thermal stress and decrease pressure loss in a feedwater sparger for use with a bwr type reactor. Constitution: A feedwater pipe and a branched pipe are joined with a reducer so as to reduce the pressure loss at the junction between them. The diameter of the reducer is increased on the side of the feedwater pipe and decreased on the side of the branched pipe. The inner face of the junction between the branched pipe and the reducer is formed with a smooth curved surface. A bent pipe for turning the water stream to substantially perpendicular direction is mounted to the branched pipe by means of welding or the like so as to stabilize the flow jetted out from the nozzle and the relation between the inner diameter D1 of the bent pipe and the inner diameter D2 at the narrowed tip of the nozzle is set as: (D2/D1)2<0.8. (Ikeda, J.)