Abstract: A simple nuclear reactor in which most of the reflector material is outside of the reactor vessel is described. The reactor vessel is a cylinder that contains all of the fuel salt and a displacement component, which may be a reflector, in the upper section of the reactor vessel. Other than the displacement component, the reflector elements including a radial reflector and a bottom reflector are located outside the vessel. The salt flows around the outside surface of the displacement component through a downcomer heat exchange duct defined by the exterior of the displacement component and the interior surface of the reactor vessel. This design reduces the overall size of the reactor vessel for a given volume of salt relative to designs with internal radial or bottom reflectors.

Abstract: The invention discloses methods, devices, systems and kits for repairing, replacing and/or augmenting natural facet joint surfaces and/or facet capsules. An implantable facet joint device of one embodiment comprises a cephalad facet joint element and a caudal facet joint element. The cephalad facet joint element includes a member adapted to engage a first vertebra, and an artificial cephalad bearing member. The caudal facet joint element includes a connector adapted for fixation to a second vertebra at a fixation point and an artificial caudal bearing member adapted to engage the cephalad bearing member. The artificial caudal bearing member is adapted for a location lateral to the fixation point.

Abstract: The invention discloses methods, devices, systems and kits for repairing, replacing and/or augmenting natural facet joint surfaces and/or facet capsules. An implantable facet joint device of one embodiment comprises a cephalad facet joint element and a caudal facet joint element. The cephalad facet joint element includes a member adapted to engage a first vertebra, and an artificial cephalad bearing member. The caudal facet joint element includes a connector adapted for fixation to a second vertebra at a fixation point and an artificial caudal bearing member adapted to engage the cephalad bearing member. The artificial caudal bearing member is adapted for a location lateral to the fixation point.

Abstract: The invention discloses methods and devices for repairing, replacing and/or augmenting natural facet joint surfaces and/or facet capsules. A facet joint restoration device of the invention for use in a restoring a facet joint surface comprises: a cephalad facet joint element comprising a flexible member adapted to engage a first vertebrae and an artificial cephalad joint; and a caudad facet joint element comprising a connector adapted for fixation to a second vertebrae and an artificial caudad joint adapted to engage the cephalad facet joint.