| 摘要 |
932,463. Nuclear fuel elements. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. Oct. 11, 1961 [Oct. 27, 1960], No. 36926/60. Class 39 (4). A rod cluster fuel assembly has bow restraint means comprising an openwork structure formed by a plurality of thin-walled members disposed edge-on to the coolant flow and embracing the fuel rods with clearance over an intermediate portion of their length. In one embodiment (Fig. 3), bowing of the fuel rods is held within limits by an openwork structure 15 of stainless steel formed by thin-walled (0.02 inch) tubular members 16 interconnected by thin-walled (0.02 inch) members 17 of web form. Flanged webs 18 connect the outer members 16 with a U-sectipn, annular support 19 (0.016 inch thickness) disposed between upper and lower graphite sleeves 28 inside a tubular housing 3 of graphite. Alternatively (Fig. 6a), the openwork structure 15 is fabricated from thin strips 5b with transverse troughs 6b and secured together remote from the openings 8b by resistance welds 7b. The strips 5b are of the same depth (0.5 inch) as the members 16, 17 of the first embodiment. In both embodiments, heat-insulating plugs 33 of sintered alumina are disposed within the fuel rods opposite the openwork structure 15. |
