| 摘要 |
1445269 Nuclear fuel elements COMMISSARIAT A L'ENERGIE ATOMIQUE 27 June 1974 [6 July 1973 3 April 1974] 28566/74 Heading G6C A nuclear fuel element comprises a juxtaposed array of wafers of ceramic fuel material enclosed between two metallic cladding plates, some at least of the wafers being provided with individual metallic protection. Such protection may be a foil wrapping 5, Fig. 1, the wafers being held in a surrounding metal frame 4. Metallic partition strips may be utilized, Figs. 2, 4 (neither shown). In a method of fabrication each wafer, of sintered UO 2 , is covered with a graphite layer (an anti-diffusion barrier) and wrapped in a sheet of ductile zirconium foil; the wrapped wafers are then assembled in rows on a plate of zircaloy, a zirconium frame 4 is formed, a zircaloy cover-plate is added, and the cladding plates and frame are welded in vacuo so as to close the fuel element. Finally a diffusion bonding operation at 830‹ C. in helium under a pressure of 1000 bars is effected. In another embodiment U-shaped members are spot-welded together to act as frame 4, Figs. 5, 6 (neither shown). In an alternative form the fuel element consists of a single row of wafers, Figs. 7, 8 (neither shown). |
