A nuclear fuel rod end distance adjusting device includes an insertion rod, a housing having a hollow space, insertion power means installed inside the housing, a connector connected between the insertion power means and the insertion rod, and an anti-rotation tool installed between the insertion power means and the connector. The insertion rod includes nuclear fuel rod tongs and configured to linearly move forward and backward. The insertion power means is configured to move in a longitudinal direction of the housing by converting a rotational motion into a linear motion. The anti-rotation tool is configured to move in the longitudinal direction of the housing by being interlocked with the linear motion of the insertion power means, but preventing rotational force of the insertion power means from being transmitted to the connector. Thereby, movement and end distance of the fuel rods can be more minutely and stably adjusted.

A nuclear fuel rod end distance adjusting device includes an insertion rod, a housing having a hollow space, insertion power means installed inside the housing, a connector connected between the insertion power means and the insertion rod, and an anti-rotation tool installed between the insertion power means and the connector. The insertion rod includes nuclear fuel rod tongs and configured to linearly move forward and backward. The insertion power means is configured to move in a longitudinal direction of the housing by converting a rotational motion into a linear motion. The anti-rotation tool is configured to move in the longitudinal direction of the housing by being interlocked with the linear motion of the insertion power means, but preventing rotational force of the insertion power means from being transmitted to the connector. Thereby, movement and end distance of the fuel rods can be more minutely and stably adjusted.

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.

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.

Carbide-based fuel assembly includes outer structural member of ceramic matrix composite material, the interior surface of which is lined in higher temperature regions with an insulation layer of porous refractory ceramic material. Continuous insulation layer extends the length of the fuel assembly or separate insulation layer sections have a thickness increasing step-wise along the length of the fuel assembly from upper (inlet) section towards bottom (outlet) section. A fuel element positioned inward of the insulation layer and between support meshes has a fuel composition including HALEU and the form of a plurality of individual elongated fuel bodies or one or more fuel monolith bodies containing coolant flow channels. Fuel assemblies are distributively arranged in a moderator block, with upper end of the outer structural member attached to an inlet for propellant and lower end of the outer structural member operatively interfaced with a nozzle forming a nuclear thermal propulsion reactor.

Method of fuel elements installation into fuel assemblies including fuel elements fabrication and control operations, application of a protective coating on each fuel element, installation of prepared fuel elements into a fuel assembly, attachment of top and bottom nozzles, washing off of the protective coating and drying. The protective coating application and fuel elements installation are combined using a water soluble lubricant containing nonylphenol ethoxylate and monobasic unsaturated fatty acids as protective coating, which is applied on the surface of the fuel element being moved during fuel elements installation in the fuel assembly on an assembly stand in horizontal direction along its own axis to the cells of grids through a protective coating application device installed on the assembly stand. The protective coating is washed off using water jets under pressure at room temperature.

Provided is an apparatus for fatigue testing a bulge tool having a WH-type skeleton, the apparatus including: a fixing bracket having tool holes penetrated through opposite sides thereof; a tool housing coupled to the tool hole of the fixing bracket and having the bulge tool inserted and installed therein; a moving rail installed at one side of the fixing bracket in a lengthwise direction of the tool housing and providing a reciprocating movement path facing the tool housing; a moving bracket reciprocating along the moving rail; a pusher protrudingly installed from the moving bracket toward the tool housing and moving in and out of the bulge tool; a measurement means installed between the pusher and the moving bracket, measuring a load applied to the bulge tool; and a drive means for generating power reciprocating the moving bracket on the moving rail.

Provided is an apparatus for fatigue testing a bulge tool having a WH-type skeleton, the apparatus including: a fixing bracket having tool holes penetrated through opposite sides thereof; a tool housing coupled to the tool hole of the fixing bracket and having the bulge tool inserted and installed therein; a moving rail installed at one side of the fixing bracket in a lengthwise direction of the tool housing and providing a reciprocating movement path facing the tool housing; a moving bracket reciprocating along the moving rail; a pusher protrudingly installed from the moving bracket toward the tool housing and moving in and out of the bulge tool; a measurement means installed between the pusher and the moving bracket, measuring a load applied to the bulge tool; and a drive means for generating power reciprocating the moving bracket on the moving rail.

Provided is a standard for mobile equipment for measuring structural deformation of a nuclear fuel assembly, the standard including: a fixed frame fixed to one side of measuring equipment accommodated in a container; a standard member configured to be attached to and detached from the fixed frame, to rotate with one end portion of the fixed frame as a center, and to correspond to a nuclear fuel assembly standard specification, wherein an upper plate provided with a coupling means configured to be coupled with a transport device is coupled on one end portion of the standard member, a lower plate configured to be erected upright on and fixed to one side of the measuring equipment is coupled on an opposite end portion of the standard member.

A pellet magazine includes a plurality of pellet bores sized to receive pellets for loading into a fuel rod. A fuel rod loading system includes a plurality of pellet loading stations each designated to load a single pellet type into one or more pellet bores of the pellet magazine, a rod loading station configured to unload pellets from the pellet bores of the pellet magazine into a fuel rod, and a conveyance system configured to transport the pellet magazine to the loading stations and then to the rod loading station in a defined sequence.