A mechanical device for grasping an object includes a receiver having a distal end shaft with an internal bore, the internal bore defining a recessed track. The recessed track defines a curvilinear path having two sets of resting peaks, each set of resting peaks being at a different height relative to a centerline of the curvilinear path. An actuator is slidably engaged with the receiver and includes a central shaft and an activator disposed at a distal end portion of the central shaft. A rotatable sleeve is disposed within the internal bore of the receiver and is coupled to the actuator. The rotatable sleeve has opposed protrusions, the opposed protrusions being disposed within the recessed track of the receiver. A pilot is secured to a distal end portion of the receiver and a grasping device is mounted to the pilot and coupled to the activator.

A mechanical device for grasping an object includes a receiver having a distal end shaft with an internal bore, the internal bore defining a recessed track. The recessed track defines a curvilinear path having two sets of resting peaks, each set of resting peaks being at a different height relative to a centerline of the curvilinear path. An actuator is slidably engaged with the receiver and includes a central shaft and an activator disposed at a distal end portion of the central shaft. A rotatable sleeve is disposed within the internal bore of the receiver and is coupled to the actuator. The rotatable sleeve has opposed protrusions, the opposed protrusions being disposed within the recessed track of the receiver. A pilot is secured to a distal end portion of the receiver and a grasping device is mounted to the pilot and coupled to the activator.

A fuel assembly handling tool that can be lowered onto the top nozzle of a fuel assembly, positively latch the top nozzle, unlatch from the top nozzle, and be raised off the top nozzle of the fuel assembly. The tool head, that interfaces with the top nozzle has load bearing grippers that latch onto the fuel assembly, that are located in a storage position up within the tool while the tool is lowered onto the fuel assembly. The gripper fingers are then lowered into position during the latching process, and are raised back to the storage position during the unlatching process. In the storage position, the gripping fingers are spaced above the fuel assembly top nozzle when the tool head is resting on the nozzle.

A fuel assembly handling tool that can be lowered onto the top nozzle of a fuel assembly, positively latch the top nozzle, unlatch from the top nozzle, and be raised off the top nozzle of the fuel assembly. The tool head, that interfaces with the top nozzle has load bearing grippers that latch onto the fuel assembly, that are located in a storage position up within the tool while the tool is lowered onto the fuel assembly. The gripper fingers are then lowered into position during the latching process, and are raised back to the storage position during the unlatching process. In the storage position, the gripping fingers are spaced above the fuel assembly top nozzle when the tool head is resting on the nozzle.

Fuel assembly for a nuclear reactor comprising a housing of longitudinal axis (X) having a central section containing nuclear-fuel pins and an upper section, forming a portion of the head of the assembly, containing a upper neutron shielding device (NSD) including neutron absorbers and means for reversibly interlocking with the housing and a moveable weight forming the head of the NSD, which is mounted so as to be able to move translationally relative to the rest of the NSD over a given path, said interlocking means being configured so that the NSD and the housing can be interlocked and uninterlocked by moving the moveable weight along the longitudinal axis by means of a grapple for extraction of the NSD, the claws of this grapple engaging with the moveable weight and the rest of the NSD being in downward longitudinal abutment in the interior of the housing.

Fuel assembly for a nuclear reactor comprising a housing of longitudinal axis (X) having a central section containing nuclear-fuel pins and an upper section, forming a portion of the head of the assembly, containing a upper neutron shielding device (NSD) including neutron absorbers and means for reversibly interlocking with the housing and a moveable weight forming the head of the NSD, which is mounted so as to be able to move translationally relative to the rest of the NSD over a given path, said interlocking means being configured so that the NSD and the housing can be interlocked and uninterlocked by moving the moveable weight along the longitudinal axis by means of a grapple for extraction of the NSD, the claws of this grapple engaging with the moveable weight and the rest of the NSD being in downward longitudinal abutment in the interior of the housing.

A combined blade guide and exchange tool, include a blade guide tool having a lower end and an upper end and a plurality of frame rails supporting a pair of lower collet housings at a lower end of the blade guide tool. A pair of fuel support grapple actuating rods are supported between the plurality of frame rails and have a first end engaging a pair of collets within the pair of lower collet housings and a second end disposed at the upper end of the blade guide tool. A blade exchange tool is releasably mounted to the upper end of the blade guide tool and includes a pair of upper collets for engaging the pair of fuel support grapple actuating rods. The blade exchange tool further including a slider and hook assembly attached to a cable guided by the blade exchange tool and adapted for engaging a control rod.

Systems join with a control rod drive and expand or contract to displace elements necessary for decoupling. Joining structures affix to on sides of the control rod drive allow discriminatory jacking by a powered drive also in contact with the control rod drive. A moveable piston tube can be displaced by this jacking with hundreds or thousands of pounds of force with respect to the control rod drive. Probes and other instrumentation and sensors are useable in the systems to accurately measure any of piston tube displacement, temperature, malfunction; drive power status, displacement or speed; and communications status. Manual interaction with the systems are not required during the jacking, and installation and removal of the systems requires no tools or great amount of time or effort. Through remote operation and brief installation, human exposure to radiation about control rod drives is minimized.

Systems join with a control rod drive and expand or contract to displace elements necessary for decoupling. Joining structures affix to on sides of the control rod drive allow discriminatory jacking by a powered drive also in contact with the control rod drive. A moveable piston tube can be displaced by this jacking with hundreds or thousands of pounds of force with respect to the control rod drive. Probes and other instrumentation and sensors are useable in the systems to accurately measure any of piston tube displacement, temperature, malfunction; drive power status, displacement or speed; and communications status. Manual interaction with the systems are not required during the jacking, and installation and removal of the systems requires no tools or great amount of time or effort. Through remote operation and brief installation, human exposure to radiation about control rod drives is minimized.

Disclosed is a system for separating and coupling a top nozzle of a nuclear fuel assembly. There is provided a lock insert configured to support the top nozzle of the nuclear fuel assembly by being coupled to a guide hole provided in a flow channel plate of the top nozzle, the lock insert including: a body in a hollow shape; and an insertion part provided on a top portion of the body and inserted into the guide hole, wherein a circumference of the insertion part is variable in size, thereby being capable of being inserted into the guide hole. Accordingly, disassembly and reassembly of the top nozzle of the nuclear fuel assembly and the lock insert are simplified, thereby simplifying and reducing the number of processes involved therein. Accordingly, the system is effective for maintenance and repair of the nuclear fuel assembly.