| 摘要 |
<p>1398057 Fuel elements GENERAL ELECTRIC CO 13 March 1973 [17 April 1972] 12092/73 Heading G6C [Also in Division C7] A fuel element comprises an elongated cladding 17 closed at each end by end closures 18, and containing fuel material 16 and a void space or plenum 20 in which is positioned a helical spring 21 and a hollow container 23. The container 23 has at least one gas permeable opening in the end portion of its wall removed from the fuel material 16 and contains a multiplicity of particles 24 of a ternary alloy having the essential components of Zr, Ni and Ti. A preferred composition is 3 to 12 wt. per cent Ni, 3 to 30 wt. per cent Ti, with the balance Zr. The alloy acts as a "getter" and reacts with water, water vapour and reactive gases at reactor operating temperatures. In the embodiment shown, the container 23, which is preferably of stainless steel, has a lower end cap (26) (Fig. 3, not shown) of solid metal and an upper end cap 25 of a screen material. The end caps 25, (26) are preferably concave and extend into the cylindrical wall of the container to facilitate welding. In an alternative embodiment (Fig. 4, not shown), the container also has at least one, preferably a multiplicity of openings in an end portion of the cylindrical container wall near the upper end cap of a screen material. A number of the fuel elements are mounted within a tubular flow channel between upper and lower end plates to form a fuel assembly, the plenums 20 being located at the coolant downstream ends of the fuel elements. The purpose of the "getter" is to prevent embrittlement of the cladding material which may be Al or Al alloy, Zr or Zr alloy, or stainless steel.</p> |
