Abstract: Jet pump clamps fit to modified jet pump assemblies at the riser pipe-restrainer bracket junction. The clamp can secure the restrainer bracket and riser pipe, relieving any welds between the same stress in the same, while preventing the restrainer bracket from moving. The clamp may include multiple members on either side of the restrainer bracket that fit into surfaces of the riser pipe. When these members are drawn together through clamping action, the underlying riser pipe is compressed. Similarly, vertically-adjustable members may seat into and/or through the restrainer bracket to hold the bracket steady. Jet pump assemblies may be prepared by forming grooves in the riser pipe and hole(s) in the restrainer bracket(s) and spherical indentations about the same. Clamps may then be installed on the grooves and through the hole(s) at installation or during a maintenance outage in a commercial nuclear power plant.