Patent Number: 
Section: claims

1. A method of fabricating a flat product of zirconium alloy, comprising:one of preparing and casting a zirconium alloy ingot containing at least 95% by weight of zirconium, and including impurities and alloying elements;shaping the ingot in order to obtain a flat arrangement;subjecting the flat arrangement to a β quenching operation under conditions that are determined to obtain within the flat arrangement an acicular structure at an end of the β quenching;subjecting the flat arrangement, after the β quenching, to a rolling operation performed in a single rolling sequence without intermediate annealing, the rolling performed at a temperature lying in a range ambient to 200° C., with a reduction ratio lying in a range 2% to 20%; andsubjecting the rolled flat arrangement to an annealing treatment in the α range or in the α+β range, performed in a temperature range 500° C. to 800° C. for 2 mm to 10 h. 2. A method according to claim 1, wherein the alloy element contents by weight are Sn=1.2% to 1.7%, Fe=0.07% to 0.20%, Cr=0.05% to 0.15%, Ni=0.03% to 0.08%, O=900 ppm to 1600 ppm. 3. A method according to claim 1, wherein the alloy element contents by weight are Sn=1.2% to 1.7%, Fe=0.18% to 0.24%, Cr=0.05% to 0.15%, O=900 ppm to 1600 ppm. 4. A method according to claim 1, wherein the alloy element contents by weight are: Sn=0.5% to 2%, Nb=0.5% to 2%, Fe=0.1% to 0.5%. 5. A method according to claim 1, wherein an alloy element contents by weight are: Sn=0.5% to 2%; Fe=0.1% to 1%; Cr=0.1% to 1.2%. 6. The method according to claim 1, wherein the alloy element contents by weight are: Nb=1.5% to 3.5%; Sn=0.5% to 2%. 7. The method according to claim 1, wherein the rolling following the β quenching is performed with a reduction ratio of 5% to 16%. 8. The method according to claim 7, wherein the rolling following the β quenching is performed with a reduction ratio of 5% to 10%. 9. The method according to claim 1, wherein the cooling of the β quenching is performed at a speed of at least 1° C./s. 10. A zirconium alloy flat product, obtained by the method:one of preparing and casting a zirconium alloy ingot containing at least 95% by weight of zirconium, and including impurities and alloying elements;shaping the ingot in order to obtain a flat arrangement;subjecting the flat arrangement to a β quenching operation under conditions that are determined to obtain within the flat arrangement an acicular structure at an end of the β quenching;subjecting the flat arrangement, after the β quenching, to a rolling operation performed in a single rolling sequence without intermediate annealing, the rolling performed at a temperature lying in a range ambient to 200° C., with a reduction ratio lying in a range 2% to 20%; andsubjecting the rolled flat arrangement to an annealing treatment in the a range or in the α+β range, performed in a temperature range 500° C. to 800° C. for 2 mm to 10 h. 11. The zirconium alloy flat product according to claim 10, wherein the element is formed into a fuel assembly element for a light water reactor. 12. The zirconium alloy flat product according to claim 10, wherein the zirconium alloy flat product is a box for a boiling water nuclear reactor. 13. The zirconium alloy flat product according to claim 10, wherein the zirconium alloy flat product is a grid for one of a boiling water reactor and a pressurized water reactor. 14. The zirconium alloy flat product according to claim 10, wherein the zirconium alloy flat product is a central tube defining, a circulation path.