METHOD AND APPARATUS FOR BWR JET PUMP INLET MIXER COMPLIANT STOP

PROBLEM TO BE SOLVED: To provide a method and apparatus for mitigating flow induced vibration (FIV) of a BWR jet pump inlet mixer and slip joint leakage.SOLUTION: An inlet mixer compliant stop may be installed in a pocket area between a riser pipe and an inlet mixer of a BWR jet pump assembly. The inlet mixer compliant stop includes a main body 22 and a foot that are separated via the tightening of one or more jacking bolts 30 used to connect the main body and the foot. A cold spring 22a attached to the main body provides a lateral force that is imparted on the inlet mixer, to force the inlet mixer away from a centerline of the riser pipe. A precise lateral force may be imparted on the inlet mixer by gauging a width of a gap between opposing bosses on a front face of the main body and a distal end of the cold spring 22a.