Nuclear fuel assembly manufacturing method, nuclear fuel assembly manufacturing plant and method of expanding such a plant

Abstract

A method is for manufacturing a nuclear fuel assembly ( 2 ) comprising nuclear fuel rods ( 4 ) arranged in a bundle and a skeleton ( 6 ) supporting the fuel rods ( 4 ). The method comprise the steps of inserting fuel rods ( 4 ) into the skeleton ( 6 ) to obtain a fuel assembly ( 2 ) and packaging the fuel assembly ( 2 ) in view of transportation. The steps are being performed in a same nuclear fuel assembly manufacturing plant ( 20 ), preferably in a same nuclear fuel assembly manufacturing building ( 60 ).

1  to  30 . (canceled) 
     
     
         31 . A method for manufacturing a nuclear fuel assembly comprising nuclear fuel rods arranged in a bundle and a skeleton supporting the fuel rods, the method comprising:
 steps of inserting fuel rods into the skeleton to obtain a nuclear fuel assembly and packaging the nuclear fuel assembly in view of transportation, the inserting and packaging steps being performed in a same nuclear fuel assembly manufacturing plant; and   a step of receiving fuel rods transported from a nuclear fuel rod manufacturing plant separated by a non-confined area from the nuclear fuel assembly manufacturing plant, wherein these fuel rods are used during the inserting step.   
     
     
         32 . The method according to  claim 31 , wherein the fuel rods are received packaged in at least a fuel assembly container, the method comprising using the fuel assembly container for packaging the nuclear fuel assembly obtained by performing the inserting step. 
     
     
         33 . The method according to  claim 31 , further comprising receiving nuclear fuel pellets transported from a nuclear fuel pellet manufacturing plant separated by a non-confined area from the nuclear fuel assembly manufacturing plant, wherein these nuclear fuel pellets are used during a fuel rod manufacturing step. 
     
     
         34 . The method according to  claim 33 , wherein the fuel rod manufacturing step comprises placing the nuclear fuel pellets on pellet trays, inserting the pellet trays in an outgassing furnace for removing potential hydrogenous contamination from the nuclear fuel pellets, loading the nuclear fuel pellets from the pellet trays into a cladding tube in a fuel rod loading station, inserting a spring into the cladding tube, filling the cladding tube with helium gas and/or welding plugs at the ends of the cladding tubes for closing the fuel rod. 
     
     
         35 . The method according to  claim 34 , wherein the step of welding the plugs of each fuel rod is performed with using a single welding station, with presenting a first end of the cladding tube to the welding station, welding a first plug to the first end, presenting a second end of the cladding tube to the welding station and welding a second plug to the second end. 
     
     
         36 . The method according to  claim 31 , further comprising a step of cleaning the fuel assembly and/or a step of inspecting the fuel assembly. 
     
     
         37 . The method according to  claim 36 , wherein the cleaning step and/or the inspecting step is/are performed with positioning the fuel assembly in a vertical position and/or substantially at ground level. 
     
     
         38 . The method according to  claim 36 , wherein the method includes the cleaning step and the cleaning step is performed by air blowing cleaning and/or high pressure cleaning and/or washing with bubbling water and/or brushing cleaning. 
     
     
         39 . The method according to  claim 36 , wherein the method includes the inspecting step and the inspecting step comprises visually inspecting the fuel assembly positioned vertically using at least one elevator for ascending and/or descending an operator along the fuel assembly. 
     
     
         40 . A plant configured for manufacturing a nuclear fuel assembly comprising nuclear fuel rods arranged in a bundle and a skeleton supporting the fuel rods, the plant comprising:
 a fuel assembly manufacturing unit comprising an inserting station configured for insertion of the nuclear fuel rods into the skeleton to obtain a fuel assembly; and   a packaging station configured for packaging the fuel assembly into a fuel assembly container in view of transportation.   
     
     
         41 . The plant according to  claim 40 , wherein the inserting station and the packaging station are located in a same building, provided with a crane configured for moving the fuel assembly between the inserting station and the packaging station. 
     
     
         42 . The plant according to  claim 40 , wherein the fuel assembly manufacturing unit comprises a cleaning station configured for cleaning of the fuel assembly and/or a fuel assembly inspection station configured for inspection of the fuel assembly. 
     
     
         43 . The plant according to  claim 42 , wherein the cleaning station and/or the fuel assembly inspection station is/are configured for cleaning and/or inspecting the fuel assembly in a vertical position and/or substantially at ground level. 
     
     
         44 . The plant according to  claim 42 , wherein the cleaning station and/or the fuel assembly inspection station comprise(s) a telescopic enclosure movable between a retracted position for loading the fuel assembly into the station and an extended position for enclosing the fuel assembly loaded into the station. 
     
     
         45 . The plant according to  claim 42 , wherein the cleaning station and/or the fuel assembly inspection station comprise(s) at least one elevator for moving an operator vertically along the nuclear fuel assembly positioned vertically. 
     
     
         46 . The plant according to  claim 40 , further comprising a fuel rod manufacturing unit comprising a pellet receiving area configured for receiving nuclear fuel pellets, a pellet inspection area configured for inspection of the nuclear fuel pellets, an outgassing station comprising at least one outgassing furnace configured to expel potential hydrogenous contamination of the nuclear fuel pellets, a cladding station configured to receive cladding tubes and check the received cladding tubes, a fuel rod loading station configured for loading the nuclear fuel pellets into a cladding tube, a welding station configured for welding plugs to the ends of the cladding tube to form a fuel rod and/or at least one fuel rod inspection station configured for inspection of the fuel rod. 
     
     
         47 . The plant according to  claim 46 , comprising the welding station and the at least one fuel rod inspection station, the plant further comprising a first conveying system configured for conveying the fuel rods to the at least one fuel rod inspection station(s), a second conveying system for conveying the fuel rods from the last inspection station to the inserting station, the first conveying system extending along a first direction and the second conveying system extending in a second direction making a non-zero angle with the first direction, and a pivoting trolley configured for transferring the fuel rods from the first conveying system to the second conveying system with pivoting the fuel rods. 
     
     
         48 . The plant according to  claim 46 , wherein the plant is housed in a building made of building modules, the fuel assembly manufacturing unit being housed in one or several building module(s) and the fuel rod manufacturing unit being housed in one of several building module(s) distinct from the building module(s) housing the fuel assembly manufacturing unit. 
     
     
         49 . The plant according to  claim 40 , further comprising a logistic area configured for shipping the fuel assemblies manufactured in the plant, for receiving skeleton parts to be assembled to obtain the skeletons and/or for receiving fuel rods. 
     
     
         50 . The plant according to  claim 40 , wherein the fuel assembly manufacturing unit is configured for interconnection with another manufacturing unit to be installed side-by-side with the fuel assembly manufacturing unit. 
     
     
         51 . The plant according to  claim 50 , wherein the fuel assembly manufacturing unit comprises at least one utility system configured for interconnection with a corresponding utility system of said other manufacturing unit connected with the fuel assembly manufacturing unit. 
     
     
         52 . The plant according to  claim 50 , wherein the fuel assembly manufacturing unit comprises at least one utility system configured to operate independently from a corresponding utility system of another manufacturing unit connected with the fuel assembly manufacturing unit. 
     
     
         53 . The plant according to  claim 50 , wherein said other manufacturing unit is another fuel assembly manufacturing unit for increasing manufacturing capacity or a fuel rod manufacturing unit configured for manufacturing fuel rods starting from nuclear fuel pellets. 
     
     
         54 . A method of expanding a plant for manufacturing a nuclear fuel assembly comprising nuclear fuel rods arranged in a bundle and a skeleton supporting the fuel rods, the plant having a fuel assembly manufacturing unit comprising an inserting station configured for insertion of fuel rods into the skeleton to obtain the fuel assembly and a packaging station configured for packaging the fuel assembly into a fuel assembly container in view of transportation, method comprising:
 a step of building at least one additional manufacturing unit and connecting the additional manufacturing unit to the fuel assembly manufacturing unit.   
     
     
         55 . The method according to  claim 54 , wherein the additional manufacturing unit is a fuel rod manufacturing unit configured for manufacturing nuclear fuel rods starting from nuclear fuel pellets. 
     
     
         56 . The method according to  claim 55 , further comprising a step of building a fuel pellet manufacturing unit configured for manufacturing UO 2  based nuclear fuel pellets and connecting the fuel pellet manufacturing unit to the fuel rod manufacturing unit. 
     
     
         57 . The method according to  claim 56 , further comprising a step of building a fuel powder manufacturing unit configured for converting UF 6  into UO 2  and connecting the fuel powder manufacturing unit to the fuel pellet manufacturing unit. 
     
     
         58 . The method according to  claim 54 , further comprising building an additional manufacturing unit which is another fuel assembly manufacturing unit for increasing manufacturing capacity. 
     
     
         59 . The method according to  claim 58 , further comprising a step of building an additional fuel pellet manufacturing unit configured for manufacturing UO 2  based nuclear fuel pellets and connecting the additional fuel pellet manufacturing unit to the additional fuel rod manufacturing unit. 
     
     
         60 . The method according to  claim 59 , further comprising a step of building an additional fuel powder manufacturing unit configured for converting UF 6  into UO 2  and connecting the additional fuel powder manufacturing unit to the additional fuel pellet manufacturing unit.