Patent Number: 062467409
Section: claims

1. A control rod for use in a nuclear reactor, said control rod comprising: a cylindrical, thin-walled sleeve comprising an SiC fiber-reinforced SiC composite material which has a porosity of 40% or less and a wall thickness of 5 mm or less;  a neutron-absorbing material disposed within said sleeve; and  a cylindrical cladding member disposed in overlying, surrounding relationship to said cylindrical, thin-walled sleeve. 2. A control rod according to claim 1, wherein said cylindrical, thin-walled sleeve comprises a circularly knitted SiC continuous fiber. 3. A control rod according to claim 1, wherein said cylindrical, thin-walled sleeve is produced by impregnating a circularly knitted SiC continuous fiber with an organic silicon compound and then calcining the thus impregnated SiC continuous fiber. 4. A control rod according to claim 1, wherein said cylindrical, thin-wall sleeve comprises three or less laminated layers of circularly knitted SiC continuous fiber.