An unlatching tool configured for actuating a movable section of a control rod drive shaft in a pressurized water reactor includes a base; a gripper assembly configured for gripping the movable section of the control rod drive shaft; a rod movably connecting the gripper assembly to the base; and a mechanical actuator fixed to the base and configured for rotating the rod to raise and lower the gripper assembly. A method for actuating a movable section of a control rod drive shaft includes installing an unlatching tool on the control rod drive shaft; latching the unlatching tool to a stationary section of the control rod drive shaft; and raising a rod connected to a gripper assembly to cause the gripper assembly to grip the movable section and move the movable section upward.

An unlatching tool configured for actuating a movable section of a control rod drive shaft in a pressurized water reactor includes a base; a gripper assembly configured for gripping the movable section of the control rod drive shaft; a rod movably connecting the gripper assembly to the base; and a mechanical actuator fixed to the base and configured for rotating the rod to raise and lower the gripper assembly. A method for actuating a movable section of a control rod drive shaft includes installing an unlatching tool on the control rod drive shaft; latching the unlatching tool to a stationary section of the control rod drive shaft; and raising a rod connected to a gripper assembly to cause the gripper assembly to grip the movable section and move the movable section upward.

An unlatching tool configured for actuating a movable section of a control rod drive shaft in a pressurized water reactor includes a base; a gripper assembly configured for gripping the movable section of the control rod drive shaft; a rod movably connecting the gripper assembly to the base; and a mechanical actuator fixed to the base and configured for rotating the rod to raise and lower the gripper assembly. A method for actuating a movable section of a control rod drive shaft includes installing an unlatching tool on the control rod drive shaft; latching the unlatching tool to a stationary section of the control rod drive shaft; and raising a rod connected to a gripper assembly to cause the gripper assembly to grip the movable section and move the movable section upward.

An unlatching tool configured for actuating a movable section of a control rod drive shaft in a pressurized water reactor includes a base; a gripper assembly configured for gripping the movable section of the control rod drive shaft; a rod movably connecting the gripper assembly to the base; and a mechanical actuator fixed to the base and configured for rotating the rod to raise and lower the gripper assembly. A method for actuating a movable section of a control rod drive shaft includes installing an unlatching tool on the control rod drive shaft; latching the unlatching tool to a stationary section of the control rod drive shaft; and raising a rod connected to a gripper assembly to cause the gripper assembly to grip the movable section and move the movable section upward.

Techniques for latching a shaft assembly with an integrated system are discussed herein. The integrated system including a nuclear reactor configured to raise a stem of the shaft assembly into a hold out. The hold out can include a sleeve, and metallic balls, the metallic balls being positioned in openings of the sleeve. The hold out can include a housing positioned around the sleeve and the metallic balls. The housing can include a gap that is narrower than a chamber of the housing. The hold out can include a spring coupled to the sleeve. The hold out can include an electromagnetic coil configured to engage the spring and the sleeve to raise the stem until the metallic balls are moved from positions between the gap of the housing and the stem, to positions between the chamber of the housing and the stem.

Techniques for latching a shaft assembly with an integrated system are discussed herein. The integrated system including a nuclear reactor configured to raise a stem of the shaft assembly into a hold out. The hold out can include a sleeve, and metallic balls, the metallic balls being positioned in openings of the sleeve. The hold out can include a housing positioned around the sleeve and the metallic balls. The housing can include a gap that is narrower than a chamber of the housing. The hold out can include a spring coupled to the sleeve. The hold out can include an electromagnetic coil configured to engage the spring and the sleeve to raise the stem until the metallic balls are moved from positions between the gap of the housing and the stem, to positions between the chamber of the housing and the stem.