METHOD FOR DESIGNING A FUEL ASSEMBLY OPTIMIZED AS A FUNCTION OF THE STRESSES IN USE IN LIGHT-WATER NUCLEAR REACTORS, AND RESULTING FUEL ASSEMBLY

A method for design of a fuel assembly for nuclear reactors, including structural components made from zirconium alloy: the mean uniaxial tensile or compressive stress to which the components are subjected during the assembly life is calculated, the zirconium alloy of which the components are made is selected according to the following criteria: those components subjected to an axial or transverse compressive stress of between −10 et −20 MPa are made from an alloy with a content of Sn between Sn=(=0.025 −0.25)% and Sn=−0.05 %: those components subjected to such a stress of between 0 et −10 MPa are made from an alloy the Sn content of which is between Sn=traces and Sn=(0.05 +1)%: those components subjected to such a stress of between 0 and +10 MPa are made from an alloy the Sn content of which is between Sn=0.05% and Sn=(0.07 +1)%: and those components subjected to such a stress of between +10 and +20 MPa are made from an alloy the content of SN of which is between 0.05% and 1.70%. A fuel assembly made according to the method.