Patent ID: 7881420

Claim:
An apparatus configured for operative attachment to a reactor component of a nuclear reactor for mitigating vibration in the component, the apparatus configured to be immersed in reactor coolant within a pressure vessel of the reactor, the apparatus comprising: a first coil spring and a second coil spring; a mass having opposing upper and lower surfaces, the upper surface attached to the first coil spring and the lower surface attached to the second coil spring so that the mass is supported within the apparatus between the first and second coil springs; and a fluid enclosure housing the coil springs and the mass, the enclosure being unsealed, allowing the reactor coolant to flow in and out of the enclosure and serve as a viscous damping medium; the fluid enclosure having a first end and a second end, the first end being attached to the first coil spring and the second end being attached to the second coil spring; a dowel affixed to the first end and the second end of the fluid enclosure, at approximately a normal angle with the first end and the second end of the fluid enclosure, and passing through a hole in the mass; the first end and the second end of the fluid enclosure being configured to operatively attach to the component to remove vibration energy in the component.