Nuclear control rod with flexure joint

A nuclear reactor control rod assembly comprising:

• a drive shaft for moving the control rod assembly relative to a core of a nuclear reactor;
• a control rod element connected to the drive shaft and insertable into the core of the nuclear reactor under a motive power of the drive shaft;
• and
• a transition assembly connecting the drive shaft to the control rod element through a finger attachment, wherein at least a portion of a first end of the transition assembly fits within and is substantially rigidly connected to a wall of a bore in a bottom of the finger attachment and a portion of a second end of the transition assembly is configured to be an upper end plug of the control rod element and is affixed to an upper end of the control rod element and wherein a connection between the finger attachment and the control rod element is through a flexible joint coupling within the transition assembly that is between the first and second end and spaced a sufficient distance along a length of the transition assembly from and below the finger attachment and joins the first end to the second end of the transition assembly to enable lateral movement of the control rod element below the finger attachment which is not limited, by the finger attachment, and the control rod element does not place a lateral load on the rigid connection of the transition assembly to the bore that would add a strain to the connection between the first end and the wall of the bore in the finger attachment or cause substantial lateral movement of the first end within the bore, wherein the flexible joint coupling is a ball and socket coupling which enables the second end of the transition assembly and the control rod to rotate laterally.