Assembly method of annular fuel element

Abstract

The invention provides a method for assembling an annular fuel element. The method comprises the following steps: a) taking an inner cladding tube, an outer cladding tube, a guide head and annular cores which are cleaned; b) installing the annular cores into the outer cladding tube one by one; c) installing the guide head into one end of the inner cladding tube; d) installing the end of the inner cladding tube with the guide head into inner holes of the annular cores; e) demounting the guide head; and f) respectively installing an upper end plug and a lower end plug on both ends of the annular fuel element. By using the method, the welding position of the inner cladding tube can not be contaminated or scratched in the assembly process, thereby satisfying the preparation requirements for the inner cladding tube before welding. The added guide head protects the welding position of the inner cladding tube, performs the functions of automatic positioning and guide, prevents the end surface dislocation of the core and the collision with the end surface of the inner cladding tube in the assembly process, effectively relieves the obstruction of the core in the assembly process, prevents the core from damage, reduces the assembly resistance, and implements assembly of the annular fuel element in a simple effective way.

Description

technical field [0001] The invention relates to the manufacture of nuclear fuel elements, in particular to an assembly method of annular fuel elements. Background technique [0002] At present, nuclear fuel rods at home and abroad are assembled by upper and lower end plugs, cladding tubes and solid or hollow pellets (some fuel rods also include springs). The assembly of annular fuel elements includes upper end plugs, lower end plugs, inner cladding tubes, outer cladding tubes, etc. The assembly of double cladding elements including inner cladding tubes is the first of its kind. At the same time, the requirements for the accuracy and assembly of various components have become higher, increasing the Assembly difficulty. The structure of the annular fuel element is shown in the appendix figure 1 . [0003] Foreign countries have identified the assembly process of annular fuel elements as a key process for the manufacture of annular fuel elements, which has been kept in a sta...

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Problems solved by technology

[0003] Foreign countries have identified the assembly process of annular fuel elements as a key process in the manufacture of annular fuel elements, which has been kept in a state of technical secrecy, and no public reports have been seen

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