Patent Number: 058928073
Section: claims

1. A nuclear fuel assembly for a pressurized water reactor comprising; a) a lower tie plate;  b) a guide tube having an upper end and a lower end, the lower end connected to the lower tie plate;  c) spacer grids spaced along the guide tube;  d) an upper tie plate which is attached to the upper end of the guide tube;  e) a plurality of nuclear fuel rods which are spaced radially and supported along the guide tube by the spacer grids, at least one of the plurality of nuclear fuel rods comprising a metallic tubular fuel rod cladding containing nuclear fuel pellets therein, and having end sealing means thereon to hermetically seal the nuclear fuel pellets within the metallic tubular fuel rod cladding, wherein at least one of the nuclear fuel rods is comprised of: 2. The fuel assembly as in claim 1 wherein the zirconium alloy further consists essentially of molybdenum. 3. The fuel assembly as in claim 2 wherein the zirconium alloy further consists essentially of niobium. 4. The fuel assembly as in claim 2 wherein the amount of molybdenum is in the range of 0.5 to 1.5 weight percent. 5. The fuel assembly as in claim 3 wherein the amount of niobium is in the range of 0.5 to 3 weight percent. 6. The fuel assembly as in claim 4 wherein the amount of niobium is in the range of 0.5 to 3 weight percent. 7. The fuel assembly as in claim 1 wherein the tubular cladding further includes an innermost layer bonded to an inner wall of the inner layer. 8. The fuel assembly as in claim 7 wherein the innermost layer is formed of a metal selected from the group consisting of zirconium and a zirconium alloy.