Abstract: A method of monitoring in real time pressure resistance welding of a cladding tube and an end plug. The method includes: a first step of detecting welding information including voltage, current, and welding force in a process of pressure resistance welding of a cladding tube and an end plug; a second step of comparing static factors obtained by calculating effective values for the welding information with predetermined reference values, respectively; a third step of calculating dynamic factors for the welding information including the gradient of instantaneous welding force, when the reference values are satisfied in the second step; and a fourth step of determining whether there is defect or not in welding quality by comparing the dynamic factors.

Abstract: A fuel pellet visual inspection device for manufacturing a nuclear fuel rod improves convenience and workability of visual inspection of a plurality of pellets by simultaneously turning over the pellet. The fuel pellet visual inspection device for manufacturing a nuclear fuel rod includes: a rotary shaft; a pair of seats hinged to the hinge shaft, arranged at both sides from the rotary shaft, and seated with a tray thereon; and a dust-collecting unit disposed under the pair of seats and collecting dust scattered from pellets.

Abstract: Disclosed is an automatic welding apparatus for an end plug of a nuclear fuel rod, which is used to perform resistance welding on a cladding tube and the end plug in a welding chamber. The automatic welding apparatus includes a welding chamber configured to perform resistance welding on an end plug and a cladding tube, a cladding tube transfer unit that has a cladding tube clamp fixedly clamping the cladding tube and a first servo motor for driving the cladding tube clamp in a horizontal direction and that horizontally transfers the cladding tube to the welding chamber, end plug welding electrodes gripping the end plug fed from an end plug feeder, an end plug transfer driver for driving the end plug welding electrodes toward the welding chamber in a forward/backward direction, and a position control module for controlling driving of the first servo motor and the end plug transfer driver.

Abstract: A fuel pellet visual inspection device for manufacturing a nuclear fuel rod improves convenience and workability of visual inspection of a plurality of pellets by simultaneously turning over the pellet. The fuel pellet visual inspection device for manufacturing a nuclear fuel rod includes: a rotary shaft; a pair of seats hinged to the hinge shaft, arranged at both sides from the rotary shaft, and seated with a tray thereon; and a dust-collecting unit disposed under the pair of seats and collecting dust scattered from pellets.

Abstract: A method of monitoring in real time pressure resistance welding of a cladding tube and an end plug. The method includes: a first step of detecting welding information including voltage, current, and welding force in a process of pressure resistance welding of a cladding tube and an end plug; a second step of comparing static factors obtained by calculating effective values for the welding information with predetermined reference values, respectively; a third step of calculating dynamic factors for the welding information including the gradient of instantaneous welding force, when the reference values are satisfied in the second step; and a fourth step of determining whether there is defect or not in welding quality by comparing the dynamic factors.

Abstract: A method for loading fuel pellets for manufacturing a nuclear fuel rod is provided. The method includes arranging fuel pellets in a row on a tray, aligning the fuel pellets in the row on the tray such that the fuel pellets are closely in contact with one another, obtaining a total length of the pellets in the row by measuring the fuel pellets in the row on the tray, and comparing the total length with a predetermined length. When the total length is smaller than the predetermined length by a difference greater than an average unit length of the pellet, one or more fuel pellets are added in the row until to increase the total length until the difference becomes smaller than the average unit length of the fuel pellet.

Abstract: Disclosed is a plasma welding apparatus for a guide thimble and guide thimble end plug of a nuclear fuel assembly, which includes: a welding chamber (100) includes an end-plug inserting part (110) into which the end plug (10) is inserted, a guide-thimble inserting part (120) which is provided on the same axis as the end-plug inserting part (110) and into which the guide thimble (20) is inserted and fixed, a torch assembling part (130) to which a plasma welding torch (131) is assembled so as to make a right angle with the end-plug inserting part (110) and the guide-thimble inserting part (120), and argon inflow and outflow ports (141, 142) through which argon is supplied or discharged; an end-plug transfer unit (210) supplying the end plug (10) to the end-plug inserting part (110); and an guide-thimble transfer unit (220) transferring the guide thimble (20) to the guide-thimble inserting part (120).

Abstract: A method for loading fuel pellets for manufacturing a nuclear fuel rod comprises arranging fuel pellets in a row on a plurality of trays, measuring a whole length of the fuel pellets in the row on each of the plurality of trays and obtaining a total length of the pellets by accumulating the whole length of the fuel pellets one after another for the plurality of trays, comparing the total length with a predetermined length, and increasing or decreasing one or more fuel pellets in the row of a last tray of the plurality of the trays such that the total length of the pellets is less than the predetermined length and a length difference between the total length of the pellets and the predetermined length is within a length of one fuel pellet.

Abstract: An apparatus for automatically loading a fuel pellet for manufacturing a nuclear fuel rod is provided. The apparatus includes a tray transfer unit that horizontally transfers the tray, a fuel pellet alignment unit that aligns fuel pellets arranged in the tray, a measurement unit that measures an entire length of the fuel pellets arranged in a row on the tray, a controller that compares an accumulated measured length with a set length, a waiting table located adjacent to the tray transfer unit to store a redundancy fuel pellet, and a fuel pellet movement unit that is driven by the controller and moves the fuel pellets between the tray and the waiting table.

Abstract: Disclosed is a fuel rod testing apparatus for a nuclear fuel assembly. The fuel rod testing apparatus includes a helium leakage testing chamber having a gate so that a fuel rod is horizontally loaded/unloaded and testing whether or not helium leaks from the fuel rod, a fuel rod upward/downward transfer unit that has first and second transfer sections located in front of the gate and horizontally installed apart from each other in order to guide the fuel rod loaded into or unloaded from the helium leakage testing chamber, and that vertically drives the first and second transfer sections, and a main frame that has a upper transfer section disposed in parallel in a lengthwise direction of the fuel rod upward/downward transfer unit and having an inclined face and a lower transfer section installed at a lower portion of the upper transfer section and having an inclined face.

Abstract: Disclosed therein are an apparatus for and a method of welding a flange to a guide thimble tube in a nuclear fuel assembly. The automatic welding apparatus includes a welding unit located on an axially conveying line of a tube for welding a surface of the tube inserted thereinto and a surface of a flange, a flange supplying unit for supplying the flange at a tube inlet of the welding unit onto the axially conveying line, and a conveying unit mounted on the axially conveying line in such a way as to move the tube and the flange on the axially conveying line, so that they are inserted into and drawn from the welding unit.

Abstract: Disclosed is an automatic welding apparatus for an end plug of a nuclear fuel rod, which is used to perform resistance welding on a cladding tube and the end plug in a welding chamber. The automatic welding apparatus includes a welding chamber configured to perform resistance welding on an end plug and a cladding tube, a cladding tube transfer unit that has a cladding tube clamp fixedly clamping the cladding tube and a first servo motor for driving the cladding tube clamp in a horizontal direction and that horizontally transfers the cladding tube to the welding chamber, end plug welding electrodes gripping the end plug fed from an end plug feeder, an end plug transfer driver for driving the end plug welding electrodes toward the welding chamber in a forward/backward direction, and a position control module for controlling driving of the first servo motor and the end plug transfer driver.

Abstract: Disclosed is a fuel rod testing apparatus for a nuclear fuel assembly. The fuel rod testing apparatus includes a helium leakage testing chamber having a gate so that a fuel rod is horizontally loaded/unloaded and testing whether or not helium leaks from the fuel rod, a fuel rod upward/downward transfer unit that has first and second transfer sections located in front of the gate and horizontally installed apart from each other in order to guide the fuel rod loaded into or unloaded from the helium leakage testing chamber, and that vertically drives the first and second transfer sections, and a main frame that has a upper transfer section disposed in parallel in a lengthwise direction of the fuel rod upward/downward transfer unit and having an inclined face and a lower transfer section installed at a lower portion of the upper transfer section and having an inclined face.

Abstract: Disclosed is a plasma welding apparatus for a guide thimble and guide thimble end plug of a nuclear fuel assembly, which includes: a welding chamber (100) includes an end-plug inserting part (110) into which the end plug (10) is inserted, a guide-thimble inserting part (120) which is provided on the same axis as the end-plug inserting part (110) and into which the guide thimble (20) is inserted and fixed, a torch assembling part (130) to which a plasma welding torch (131) is assembled so as to make a right angle with the end-plug inserting part (110) and the guide-thimble inserting part (120), and argon inflow and outflow ports (141, 142) through which argon is supplied or discharged; an end-plug transfer unit (210) supplying the end plug (10) to the end-plug inserting part (110); and an guide-thimble transfer unit (220) transferring the guide thimble (20) to the guide-thimble inserting part (120).

Abstract: Disclosed therein are an apparatus for and a method of welding a flange to a guide thimble tube in a nuclear fuel assembly. The automatic welding apparatus includes a welding unit located on an axially conveying line of a tube for welding a surface of the tube inserted thereinto and a surface of a flange, a flange supplying unit for supplying the flange at a tube inlet of the welding unit onto the axially conveying line, and a conveying unit mounted on the axially conveying line in such a way as to move the tube and the flange on the axially conveying line, so that they are inserted into and drawn from the welding unit.

Abstract: An apparatus for automatically loading a fuel pellet for manufacturing a nuclear fuel rod includes a tray transfer unit that horizontally transfers a tray; a fuel pellet alignment unit that aligns fuel pellets arranged in the tray; a measurement unit that measures an entire length of the fuel pellets arranged in a row on the tray; a controller that compares an accumulated measured length with a set length; and a waiting table located adjacent to the tray transfer unit to store a redundancy fuel pellet; and a fuel pellet movement unit configured to be driven by the controller and configured to move the fuel pellet between a tray of which length measurement is completed by the measurement unit and the waiting table to increase or decrease the fuel pellet arranged on the tray.

Abstract: Disclosed therein are an apparatus for and a method of automatically welding a flange to a guide thimble tube in a nuclear fuel assembly. The automatic welding apparatus includes: a welding part located on an axially conveying line of a tube for welding a welded surface of the tube inserted thereinto and a welded surface of a flange; a flange supplying part for supplying the flange at a tube inlet of the welding part onto the axially conveying line; and a conveying part mounted on the axially conveying line in such a way as to move the tube and the flange on the axially conveying line, so that they are inserted into and drawn from the welding part.

Abstract: Disclosed is an apparatus for performing an automated cleaning of nuclear fuel cladding-tubes. The apparatus comprises a pre-cleaning holding section disposed at a first side of the apparatus, a primary cleaning-material supplying section and a primary cleaning section disposed at a second side of the apparatus, a secondary cleaning section and a secondary cleaning material supplying section disposed at the second side of the apparatus and beside the primary cleaning section, an inspection section disposed at a third side of the apparatus that is opposite to the second side, and a post-cleaning holding section disposed at the fourth side of the transferring section. The pre-cleaning holding section and the post-cleaning holding section includes a cladding-tube guide where the cladding-tube is loaded before and after cleaning. Primary and secondary cleaning material supply sections are disposed at a lateral side of the primary and secondary cleaning sections respectively.

Abstract: Disclosed is an apparatus for performing an automated cleaning of nuclear fuel cladding-tubes. The apparatus comprises a pre-cleaning holding section disposed at a first side of the apparatus, a primary cleaning-material supplying section and a primary cleaning section disposed at a second side of the apparatus, a secondary cleaning section and a secondary cleaning material supplying section disposed at the second side of the apparatus and beside the primary cleaning section, an inspection section disposed at a third side of the apparatus that is opposite to the second side, and a post-cleaning holding section disposed at the fourth side of the transferring section. The pre-cleaning holding section and the post-cleaning holding section includes a cladding-tube guide where the cladding-tube is loaded before and after cleaning. Primary and secondary cleaning material supply sections are disposed at a lateral side of the primary and secondary cleaning sections respectively.

Abstract: Disclosed therein are an apparatus for and a method of automatically welding a flange to a guide thimble tube in a nuclear fuel assembly. The automatic welding apparatus includes: a welding part located on an axially conveying line of a tube for welding a welded surface of the tube inserted thereinto and a welded surface of a flange; a flange supplying part for supplying the flange at a tube inlet of the welding part onto the axially conveying line; and a conveying part mounted on the axially conveying line in such a way as to move the tube and the flange on the axially conveying line, so that they are inserted into and drawn from the welding part.