Abstract: A device and method for augmenting support and suppressing vibration for U-bend tubes and tube spacer supports in a vapor generator vessel. The device is installed in the vapor generator vessel from outside the vessel through dual oppositely oriented openings cut through the wall and inner shroud of the generator vessel. The device extension rods are inserted through one of the openings, and the vibration suppressor blades are each inserted sequentially through the other opening and installed on a support rod and then rotated upwardly into place between the parallel tube batwing spacer supports by using a special push/twist tool, after which the support rod is indexed forward to provide positive engagement between the rod and blade, such as by a rod key and blade slot means. The suppressor blades are retained in place on the step block and rod by a clamp block attached to the step block, and the vessel dual openings are then covered by pressure-tight flange plates.