Compactable control element assembly for a nuclear reactor

An absorber assembly for movement into and out of the core region of a nuclear reactor, the assembly comprising:

• a longitudinally movable support member;
• a plurality of longitudinally extending parallel absorber elements supported from said support member, said absorber elements being arranged in a laterally spaced array;
• means for laterally compacting said laterally spaced parallel array of absorber elements as said support member is moved in one longitudinal direction;
• and
• means for laterally uncompacting said array of absorber elements when movement of said support member in said one longitudinal direction is stopped.

A control element assembly for a nuclear reactor comprising:

• a duct positionable within the core of the nuclear reactor;
• a support member longitudinally movable within said duct;
• a plurality of longitudinally extending parallel absorber pins mounted to said support member for movement therewith, said pins being arranged with respect to said support member and said duct to provide at least a predetermined minimum lateral spacing between said pins and the wall of said duct;
• drive means for longitudinally moving said support member within said duct;
• latch means associated with said drive means for releasably coupling said support member to said drive means;
• means associated with said latch means for the propelling said support member and said absorber pins into the core when said latch means releases said support member;
• and
• means responsive to the longitudinal motion into the core of said support member for increasing the predetermined minimum lateral spacing between said absorber pins and the wall of said duct.