Abstract: An improved core servicing apparatus for a nuclear reactor having a vessel, a head for the vessel, one or more penetration openings in the head and a core within the vessel of the type having an array of fuel assemblies and including apertures in the array for neutron absorbers. The servicing apparatus includes a support column adapted to be supported by and depend from the head in registry with a penetration opening; a plurality of core servicing elements which may include neutron absorber actuating means and/or instrument packages are supported by the support column; and means are provided for laterally displacing at least some of the servicing elements relative to the support column between a laterally compact and a laterally expanded configuration.In one embodiment, instruments may be located at the lower end of long resilient cables and are longitudinally movable within and beyond guide channels supported by the support column.

Abstract: A fuel handling machine for a liquid metal cooled nuclear reactor in which a retractable handling tube and gripper are lowered into the reactor to withdraw a spent fuel assembly into the handling tube. The handling tube containing the fuel assembly immersed in liquid sodium is then withdrawn completely from the reactor into the outer barrel of the handling machine. The machine is then used to transport the spent fuel assembly directly to a remotely located decay tank. The fuel handling machine includes a decay heat removal system which continuously removes heat from the interior of the handling tube and which is capable of operating at its full cooling capacity at all times. The handling tube is supported in the machine from an articulated joint which enables it to readily align itself with the correct position in the core. An emergency sodium supply is carried directly by the machine to provide make up in the event of a loss of sodium from the handling tube during transport to the decay tank.

Abstract: A compactable control element assembly for a nuclear reactor in which the absorber pins of the assembly are compacted during downward movement of the pin and are returned to their uncompacted state when downward movement is stopped. The control element assembly comprises a support member longitudinally movable within a control assembly duct and a pluraity of absorber pins supported laterally outward of the support member and within the duct by pairs of support arms. The absorber pins are pivotably mounted to the support arms and the support arms in turn are supported from the support member for upward pivotable movement in a longitudinal plane. As the support member is moved downward, the support arms pivot upwardly and the absorber pins move upwardly and inwardly towards the support member. When the support member is stopped the absorber pins return to their uncompacted position.