Nuclear fuel assembly

Abstract

Abstract A fuel assembly for nuclear reactors wherein grid members having openings in which a plurality of fuel rods are laterally supported are structurally integrated by temperature compensated longitudinal members of an elongated framing means so as to minimize thermal blowing of the fuel rods. In one embodiment, the longitudinal members of the elongated framing means comprises a number of insulated tubes, each provided with an internal coolant flow channel and joined proximate their ends by the grid members. The grid members on each end are in turn joined by a sheer resisting web structure to form a shear-grid such that a transverse temperature gradient produces end moments on the fuel assembly which balance each other. In another embodiment, the insulated tubes are replaced by struts constructed of several materials of selected lengths and thermal expansion properties so joined that the expansion of the various materials products no overall elongation of the strut between selected points. In still another embodiment, the shear-grid structures are formed as and connected by a temperature compensated enclosure to form a "canned" fuel assembly having essentially zero expansion between a plurality of lateral planes at which the grids may be located. Optionally, groups of fuel rods may be joined by shear webs so as to produce an integral structure which may be inserted in the grid openings and thereby produce increased stability due to an increased moment of inertia.

Inventors

• 👤 N Georges
• 👤 W Pennell

Bibliographic Details