Patent ID: 6898260

Claim:
A fuel element for a pressurized water reactor, comprising: a laterally open skeleton having control-rod guide tubes each with a first end and a second end, spacers fastened to said control-rod guide tubes, a fuel element head disposed at said first end of said control-rod guide tubes, and a fuel element foot disposed at said second end of said control-rod guide tubes; and gastight cladding tubes inserted into said skeleton and each filled with a column of fuel pellets, at least one of said gastight cladding tubes having a multilayer wall, said multilayer wall including: a mechanically stable matrix formed of a first zirconium alloy disposed in a middle of said multilayer wall, said first zirconium alloy containing 1.0 to 1.8% Sn, 0.2 to 0.6% Fe, and up to 0.3% Cr, a remainder being zirconium of industry purity, said first zirconium alloy having precipitations of secondary phases, a size of the precipitations corresponding to a standardized annealing duration of 2 to 80×10 −˜ h; and a thinner protective layer of a second zirconium alloy alloyed to a lesser extent than said first zirconium alloy, said thinner protective layer bound metallurgically to said matrix and disposed on an inside of said matrix facing said fuel pellets, said second zirconium alloy containing at least 0.2% and up to 0.8% by weight of iron, a remainder being zirconium of industrial purity, said second zirconium alloy having precipitations of secondary phases, a size of the precipitations corresponding to a standardized annealing duration of about 0.1 to 3×10 −18 h.