Abstract: A nuclear fuel cladding element comprises a substrate made of a material containing zirconium and a protective coating covering the substrate on the outside. The protective coating is being made of a material containing chromium, and has a columnar microstructure composed of columnar grains and having on the outer surface thereof a microdroplet density of less than 100 per mm2.

Abstract: A tubular component for a pressurised-water nuclear reactor, has the following composition by weight: 0.8%?Nb?2.8%; traces?Sn?0.65%; 0.015%?Fe?0.40%; preferably 0.020%?Fe?0.35%; traces?C?100 ppm; 600 ppm?O?2300 ppm; preferably 900 ppm?O?1800 ppm; 5 ppm?S?100 ppm; preferably 8 ppm?S?35 ppm; traces?Cr+V+Mo+Cu?0.35%; traces?Hf?100 ppm; F?1 ppm; the remainder being zirconium and impurities resulting from production. The tubular component has an outer surface with a roughness Ra less than or equal to 0.5 ?m, obtained following a final mechanical polishing step. The outer surface has a roughness Rsk?1 in absolute value and a roughness Rku?10.

Abstract: A treatment process for a zirconium alloy is provided. The process includes the following steps: a zirconium alloy ingot is prepared, the composition of which is: 0.40%?Nb?1.05%; traces?Sn?2%; (0.5Nb?0.25) %?Fe?0.50%; traces?Ni?0.10%; traces?(Cr+V) %?0.50%; traces?S?35 ppm; 600 ppm?O?2000 ppm, preferably 1200 ppm?O?1600 ppm; traces?Si?120 ppm; traces?C?150 ppm; the remaining being Zr and unavoidable impurities; the ingot undergoes at least one reheating and hot shaping step, and possibly a reheating and quenching step following a hot shaping step; optionally the hot-shaped ingot undergoes an annealing; the hot-shaped and possibly annealed ingot undergoes at least one cycle of cold rolling-annealing steps; the annealing of at least one of the cold rolling-annealing steps being performed at a temperature comprised between 600° C. and the lowest of either 700° C. or (710?20×Nb %)° C.

Abstract: A treatment process for a zirconium alloy is provided. The process includes the following steps: a zirconium alloy ingot is prepared, the composition of which is: 0.40%?Nb?1.05%; traces?Sn?2%; (0.5Nb?0.25)%?Fe?0.50%; traces?Ni?0.10%; traces?(Cr+V)%?0.50%; traces?S?35 ppm; 600 ppm?O?2000 ppm, preferably 1200 ppm?O?1600 ppm; traces?Si?120 ppm; traces?C?150 ppm; the remaining being Zr and unavoidable impurities; the ingot undergoes at least one reheating and hot shaping step, and possibly a reheating and quenching step following a hot shaping step; optionally the hot-shaped ingot undergoes an annealing; the hot-shaped and possibly annealed ingot undergoes at least one cycle of cold rolling-annealing steps; the annealing of at least one of the cold rolling-annealing steps being performed at a temperature comprised between 600° C. and the lowest of either 700° C. or (710?20×Nb %)° C., and the annealings of the other cold rolling-annealing steps, if any, being performed at a temperature not higher than 600° C.

Abstract: A zirconium alloy that is resistant to shadow corrosion for a boiling water nuclear reactor fuel assembly component, the alloy being characterized in that: its composition in percentages by weight is as follows: Nb=0.4%-4.5% Sn=0.20%-1.7% Fe=0.05%-0.45% Fe+Cr+Ni+V=0.05%-0.45%, with Nb?9×[0.5?(Fe+Cr+V+Ni)] S=traces-400 ppm C=traces-200 ppm Si=traces-120 ppm O=600 ppm-1800 ppm the balance being Zr and impurities from processing; in that, during fabrication, after its last hot deformation, it is subjected to one or more heat treatments lying in the range 450° C. to 610° C. for a total duration of at least 4 h, with at least one cold rolling operation with a rolling ratio of at least 25%; and in that a final heat treatment operation is performed at a temperature in the range 450° C. to 610° C. for 1 minute to 20 hours. A fuel assembly component made of the alloy, a fuel assembly including the component, and the use thereof.

Abstract: 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%.

Abstract: The invention relates to a method of producing a flat zirconium alloy product with a Kearns factor (cross direction) of between 0.3 and 0.7. The inventive method consists in: producing an ingot containing Nb=0.5 to 3.5%, Sn=0 to 1.5%, Fe=0 to 0.5%, Cr+V=0 to 0.3%, S=0 to 100 ppm, O=0 to 2000 ppm, Si=0 to 150 ppm, the remainder being zirconium and impurities; shaping the aforementioned ingot; performing one or more hot rolling operations in order to obtain a flat product, whereby the last operation is performed at between(810?20×Nb %)° C. and 1100° C. and is not followed by any quenching from phase ?+? or ?; optionally performing an annealing operation at a maximum of 800° C.; and performing one or more cold rolling and annealing operations, said annealing operations being performed at a maximum of 800° C. The invention also relates to the flat zirconium alloy product thus obtained.

Abstract: A large ingot is produced by casting the zirconium alloy, then the ingot is forged in two stages to obtain the semi-finished product wherein the first stage of forging the ingot is performed at a temperature at which the zirconium alloy is in a state comprising crystalline ? and ? phases.

Abstract: A method for production of a fuel cladding tube for a nuclear reactor, characterized by the preparation of an ingot of an alloy of zirconium with the following composition by weight %: 0.8%?Nb?2.8%, traces?Sn?0.65%, 0.015%?Fe?0.40%, C?100 ppm, 600 ppm?O?2300 ppm, 5 ppm?S?100 ppm, Cr+V?0.25%, Hf?75 ppm and F?1 ppm the remainder being zirconium and impurities arising from production. The ingot is then subjected to forging, a hardening and thermomoechanical treatments comprising cold laminations separated by intermediate annealing, all intermediate annealings being carried out at a temperature below the ???+? transition temperature of the alloy, finishing with a recrystallization annealing and resulting in the production of a tube, whereupon an optional external cleaning of the tube is carried out and a mechanical polishing of the external surface of the tube is carried out to give a roughness Ra less than or equal to 0.5 ?m. The invention further relates to a fuel cladding tube obtained thereby.

Abstract: A zirconium alloy that is resistant to shadow corrosion for a boiling water nuclear reactor fuel assembly component, the alloy being characterized in that: its composition in percentages by weight is as follows: Nb=0.4%-4.5% Sn=0.20%-1.7% Fe=0.05%-0.45% Fe+Cr+Ni+V=0.05%-0.45%, with Nb?9×[0.5?(Fe+Cr+V+Ni)] S=traces-400 ppm C=traces-200 ppm Si=traces-120 ppm O=600 ppm-1800 ppm the balance being Zr and impurities from processing; in that, during fabrication, after its last hot deformation, it is subjected to one or more heat treatments lying in the range 450° C. to 610° C. for a total duration of at least 4 h, with at least one cold rolling operation with a rolling ratio of at least 25%; and in that a final heat treatment operation is performed at a temperature in the range 450° C. to 610° C. for 1 minute to 20 hours. A fuel assembly component made of the alloy, a fuel assembly including the component, and the use thereof.

Abstract: 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%.

Abstract: A method of fabricating a zirconium alloy flat product, the method being characterized by: preparing or casting a zirconium alloy ingot containing at least 95% by weight of zirconium, and including the usual impurities and alloying elements; shaping said ingot in order to obtain a flat product; subjecting said flat product to a ? quenching operation under conditions that are determined to obtain within the flat product an acicular structure at the end of said ? quenching; subjecting said flat product, after the ? quenching, to a rolling operation performed in a single rolling sequence without intermediate annealing, said rolling being performed at a temperature lying in the range ambient to 200° C., and having a reduction ratio lying in the range 2% to 20%; and subjecting said rolled flat product to an annealing treatment in the a range or in the ?+? range, performed in the temperature range 500° C. to 800° C. for 2 minutes to 10 hours.

Abstract: A method for production of a fuel cladding tube for a nuclear reactor, characterised by the preparation of an ingot of an alloy of zirconium with the following composition by weight %: 0.8%?Nb?2.8%, traces?Sn?0.65%, 0.015%?Fe?0.40%, C?100 ppm, 600 ppm?O?2300 ppm, 5 ppm?S?100 ppm, Cr+V?0.25%, Hf?75 ppm and F?1 ppm the remainder being zirconium and impurities arising from production. The ingot is then subjected to forging, a hardening and thermomoechanical treatments comprising cold laminations separated by intermediate annealing, all intermediate annealings being carried out at a temperature below the ???+? transition temperature of the alloy, finishing with a recrystallisation annealing and resulting in the production of a tube, whereupon an optional external cleaning of the tube is carried out and a mechanical polishing of the external surface of the tube is carried out to give a roughness Ra less than or equal to 0.5 ?m. The invention further relates to a fuel cladding tube obtained thereby.

Abstract: The invention relates to a method of producing a flat zirconium alloy product with a Kearns factor (cross direction) of between 0.3 and 0.7. The inventive method consists in: producing an ingot containing Nb=0.5 to 3.5%, Sn=0 to 1.5%, Fe=0 to 0.5%, Cr+V=0 to 0.3%, S=0 to 100 ppm, O=0 to 2000 ppm, Si=0 to 150 ppm, the remainder being zirconium and impurities; shaping the aforementioned ingot; performing one or more hot rolling operations in order to obtain a flat product, whereby the last operation is performed at between(810-20×Nb %)° C. and 1100° C. and is not followed by any quenching from phase ?+? or ?; optionally performing an annealing operation at a maximum of 800° C.; and performing one or more cold rolling and annealing operations, said annealing operations being performed at a maximum of 800° C. The invention also relates to the flat zirconium alloy product thus obtained.

Abstract: A method of fabricating a zirconium alloy flat product, the method being characterized by: preparing or casting a zirconium alloy ingot containing at least 95% by weight of zirconium, and including the usual impurities and alloying elements; shaping said ingot in order to obtain a flat product; subjecting said flat product to a ? quenching operation under conditions that are determined to obtain within the flat product an acicular structure at the end of said ? quenching; subjecting said flat product, after the ? quenching, to a rolling operation performed in a single rolling sequence without intermediate annealing, said rolling being performed at a temperature lying in the range ambient to 200° C., and having a reduction ratio lying in the range 2% to 20%; and subjecting said rolled flat product to an annealing treatment in the a range or in the ?+? range, performed in the temperature range 500° C. to 800° C. for 2 minutes to 10 hours.

Abstract: A large ingot is produced by casting the zirconium alloy, then the ingot is forged in two stages to obtain the semi-finished product wherein the first stage of forging the ingot is performed at a temperature at which the zirconium alloy is in a state comprising crystalline ? and ? phases.

Abstract: A large ingot is produced by casting the zirconium alloy, then the ingot is forged to obtain the semi-finished product wherein the semi-finished product can be a slab for production of a flat product is produced from the large cast ingot in a single forging operation at a temperature at which the zirconium alloy is in a state comprising both the crystalline ? and ? phases of the alloy.

Abstract: A process for the fabrication of zirconium alloy sheet specifically intended for the manufacture of structural elements for boiling water reactors, which includes the following steps:a) producing in a vacuum an ingot having the composition of the desired alloy;b) forging and hot rolling the ingot;c) quenching of the blank thus obtained after reheating in the beta range;d) hot rolling after heating;e) heat treatment in the alpha range;f) at least one cycle of cold rolling followed by a heat treating in the alpha range; andg) final cold rolling followed by subcritical annealing in the alpha range;where the hot rolling of the sheet after quenching from the beta range is carried out in an initial direction, then in a direction perpendicular to the initial direction.

Abstract: A process for the manufacture of a sheet, band or strip of zirconium alloy or hafnium alloy, comprising hot roughing of an ingot into a blank, then hot rolling of this blank in the alpha domain, this hot rolling including several passes which follow one or more reheatings in a furnace at one or more temperatures (TR), each of which improves the formability of this blank, then cold rolling which consists of one or more cycles of rolling pinch passing/heat treatment. The hot rolling pass following the last furnace reheating is followed by reheating of the hot rolled blank by at least 100.degree. C. at more than 4.degree. C./s by infrared heating means with a wavelength between 0.8 and 5 micrometers. The hot rolling is then continued until the thickness at the end of the hot rolling is less than or equal to 0.8 times the thickness of the hot rolled blank. The product obtained is used for the manufacture of zirconium or hafnium alloy parts for water-type nuclear reactors.

Abstract: A process for the manufacture of a flat product of zirconium alloy having a width between 50 and 600 mm from a flat cold rolled product. The cold rolled product is heated to the beta range and maintained in the beta range using an infra-red heating device with a wavelength of between 0.8 and 5 microns, the maximum temperature difference over the width of the product being less than 35.degree. C. The product is then rapidly cooled and optionally annealed to obtain a flat product, which can be a strip, sheet or band.