Method for designing a fuel assembly optimised as a function for the conditions of use in light water nuclear reactors and resulting fuel assembly

Designing a fuel assembly for a light-water nuclear reactor comprising structural components of zirconium alloy, comprises calculating uniaxial constraints using traction/compression to which the components are subjected during the life of assembly; and choosing the alloys in which the components are made from the criteria i.e. those subjected to a constraint of axial compression or cross compression e.g. - 10 to - 20 MPa are made in an alloy of which the content of elements other than zirconium does not exceed 5%, and of which the content of tin is e.g. - 0.025. to 0.25% to - 0.05.%. Designing a fuel assembly for a light-water nuclear reactor comprising structural components of zirconium alloy, comprises calculating uniaxial constraints using traction or compression to which those components are subjected during the life of assembly; and choosing the zirconium alloys in which the components are made from the criteria i.e. those subjected to a constraint of axial compression or cross compression () (- 10 to - 20 MPa), (0 to - 10 MPa), (0 to + 10 MPa) and (+ 10 to + 20 MPa), respectively, are made in an alloy of which the content of elements other than zirconium does not exceed 5%, and of which the content of tin is (- 0.025. to 0.25)% to (- 0.05.%), traces to (0.05.+ 1)%, (0.05.%) to (0.07+ 1%) and (0.5%) to (1.7%), respectively. An independent claim is included for a fuel assembly for a light-water nuclear reactor comprising the structural components in the zirconium alloy subjected to a constraint of axial compression or cross compression (), comprising the components, which are made of the alloys by applying the process.