Seismic attenuation system for a nuclear reactor

A system for attenuating seismic forces comprising:

• a reactor pressure vessel containing nuclear fuel, wherein the reactor pressure vessel comprises a bottom head;
• a containment vessel that houses the reactor pressure vessel, wherein the containment vessel comprises a bottom head;
• a base support that is configured to contact a support surface on which the containment vessel is positioned in a substantially vertical orientation;
• and
• an attenuation device located between the bottom head of the reactor pressure vessel and the bottom head of the containment vessel, wherein seismic forces that travel from the base support to the reactor pressure vessel via the containment vessel are attenuated by the attenuation device in a direction that is substantially lateral to the vertical orientation of the containment vessel.

An apparatus, comprising:

• means for transmitting a seismic force to a containment vessel, wherein the containment vessel houses a reactor pressure vessel that is spaced apart from the containment vessel by an annular containment volume;
• means for supporting a weight of the reactor pressure vessel within the containment vessel, wherein the means for supporting passes through the annular containment volume;
• and
• means for attenuating the seismic force that is received by the reactor pressure vessel, wherein the means for attenuating does not support the weight of the reactor pressure vessel.

A method, comprising:

• supporting, with a support structure, a weight of a reactor pressure vessel housed within a containment vessel, wherein the reactor pressure vessel is spaced apart from the containment vessel by an annular containment volume, and wherein the support structure passes through the annular containment volume;
• transmitting a seismic force through the containment vessel;
• and
• attenuating, with an attenuation device located along a longitudinal centerline of the reactor pressure vessel, the seismic force that is received from the containment vessel by the reactor pressure vessel, wherein the attenuation device attenuates the seismic force in a direction transverse to the longitudinal centerline, and wherein the attenuation device does not support the weight of the reactor pressure vessel.