GB1173928A - Nuclear Fuel-Element - Google Patents

Abstract

1,173,928. Fuel elements. GENERAL ELECTRIC CO. 28 Dec., 1966 [26 Jan., 1966], No. 57996/66. Heading G6C. A fuel element comprises nuclear fuel 50 housed in an elongated cladding tube 45, the upper end of which includes a plenum chamber 54 to collect fission product gases, with welded end plugs 46, 48 sealing the ends of the tube, at least one thin metal wafer, e.g. wafers 102, 102<SP>1</SP> being disposed between the fuel and the lower end plug 48 to provide thermal interfaces both between the fuel and the wafer(s) and between the wafer(s) and the plug to reduce the quantity of heat transferred from the fuel to the plug 48 and thus prevent excessive stresses from being formed in the welded connection between the plug 48 and the cladding tube 45. The two thin metal wafers 102, 102<SP>1</SP> are triangular and have rounded apexes, one wafer being displaced through 60 degrees with respect to the other. The cladding tube is preferably made of Zr and the wafers of Zr or stainless steel. The use of triangular wafers is particularly advantageous in that when such wafers are inserted into the upper end of the cladding tube, which is tilted so that the wafers ride down the tube, they invariably come to rest flat against the face of either the end plug or another wafer which has already been inserted. Circular wafers, for example, when inserted in this manner frequently come to rest on their edges at the bottom of the tube. A fuel element assembly (Fig. 1, not shown) is described comprising a plurality of fuel elements of the above construction.