Tubular component of pressurised water nuclear reactor, and method for manufacturing said component

A method for producing a fuel cladding tube for a nuclear reactor, comprising:

• preparing a zirconium-alloy ingot having the following composition by weight:
• 0.8%≤Nb≤2.8%;
• traces≤Sn≤0.65%;
• 0.015%≤Fe≤0.40%;
• traces≤C≤100 ppm;
• 600 ppm≤O≤2300 ppm;
• 5 ppm≤S≤100 ppm;
• traces≤Cr+V+Mo+Cu≤0.35%;
• traces≤Hf≤100 ppm;
• F≤1 ppm;
• a remainder being zirconium and impurities resulting from production;
• subjecting the ingot to forging, optionally followed by quenching, then to extrusion and thermomechanical treatments including cold rolling separated by intermediate annealings, wherein all of the intermediate annealings are carried out at a temperature below the transus temperature→α+β of the alloy, ending with a relief, semi-recrystallization or recrystallization annealing, and resulting in a production of a tube;
• optionally, carrying out chemical pickling and/or electrolytic polishing and/or initial mechanical polishing of an outer surface of the tube;
• and
• carrying out a final mechanical polishing of the outer surface to give the outer surface a roughness Ra less than or equal to 0.5 μm, a roughness Rsk≤1 in absolute value and a roughness Rku≤10;
• wherein the fuel cladding tube is configured such that a breakaway of the fuel cladding tube does not take place before at least 10000 seconds when the fuel cladding tube is submitted to steam corrosion at 1000° C. and atmospheric pressure.

A tubular component for a pressurised-water nuclear reactor, having the following composition by weight:

• 0.8%≤Nb≤2.8%;
• traces≤Sn≤0.65%;
• 0.015%≤Fe≤0.40%;
• traces≤C≤100 ppm;
• −600 ppm≤O≤2300 ppm;
• −5 ppm≤S≤100 ppm;
• traces≤Cr+V+Mo+Cu≤0.35%;
• traces≤Hf≤100 ppm;
• F≤1 ppm;
• a remainder being zirconium and impurities resulting from production, an outer surface of which has a roughness Ra less than or equal to 0.5 μm, obtained following a final mechanical polishing step, the outer surface having a roughness Rsk≤1 in absolute value and a roughness Rku≤10;
• wherein the tubular component is configured such that an increase in a mass of the tubular component resulting from oxidation is 10.67 mg/cm2 or less when the tubular component is submitted to steam corrosion at 1000° C. and atmospheric pressure for 10000 seconds.