Patent Number: 047524405
Section: abstract

A control rod for a nuclear reactor comprises a number of elongated absorber plates (13-16) which are each provided with a plurality of channels (18b), said channels extending substantially perpendicularly to the longitudinal direction of the absorber plate, containing powdered boron carbide or other powdered absorber material which gives off gas and swells upon irradiation, and being hermetically separated from the surroundings of the control rod by an edge portion (30), which is arranged at an edge (31) running in the longitudinal direction of the absorber plate and comprises a gas-tight edge (31) and a longitudinal space (32) arranged inside said edge and being in open communication with and permitting a gas flow between the different channels in the absorber plate. Between the powdered absorber material and the edge portion there is arranged, in a plurality of channels (18b), a body (21) of hafnium or other metallic absorber material which allows the passage of gas but prevents or radically counteracts the passage of powdered absorber material.