Method for manufacturing a nuclear fuel element and nuclear fuel element

A method for manufacturing a nuclear fuel element, the manufacturing method comprising:

• obtaining a core in the form of a sheet containing a uranium-based fissile material;
• coating the core with an anti-diffusion layer to obtain a coated core;
• inserting the coated core into a cladding with interposition, between the coated core and the cladding, of one or more intermediate layer(s), and pressing a resulting multilayer assembly so as to close the cladding in a sealed manner, each intermediate layer being made of a ductile metal alloy and/or having a conventional yield strength which differs by no more than 30% from that of the cladding material, an elongation at break which differs by no more than 30% from that of the cladding material and/or a distributed relative elongation which differs by no more than 30% from that of the cladding material.