Abstract: A fuel rod for a light water reactor comprises a cladding tube which comprises a zirconium alloy having a composition including 0.6 to 2.0% by weight of Nb, 0.5 to 1.5% by weight of Sn, 0.05 to 0.3% by weight of Fe, and the balance being Zr and incidental impurities; uranium oxide fuel pellets packed in the cladding tube; and end plugs closing both ends of the cladding tube. The cladding tube is sealed by TIG welding with the end plugs. Precipitates having grain diameters of 0.01 to 0.5 .mu.m and comprise intermetallic compounds containing Zr, Nb and Fe are present at grain boundaries in the structure of heat affected zones of the cladding tube, the heat affected zone being adjacent to a bead formed by TIG welding.

Abstract: A method is disclosed for welding an end plug to an open end of a surface-coated tube in order to provide a control rod. First, the end plug is brought into pressed abutment with the open end of the surface-coated tube. Then, resistance welding is performed in order to join the end plug with the open end of the surface-coated tube by applying electric current between the surface-coated tube and the end plug to heat the same while keeping the end plug pressed in abutment with the open end of the surface-coated tube. With these procedures, even when a surface-coated tube having a hard coating formed over its entire length is employed, the coating material is prevented from dissolving into the welded portion and therefore ensures an excellent welding quality, and the resulting control rod exhibits excellent characteristics over its entire length.

Abstract: A resistance welding method for a fuel rod is presented in which the gas seal opening is closed with a sealing material of the same composition as the end plug material. The method enable to perform welding stably in a pressurized welding chamber, and the process is amenable to automation. The sealing material body is made of a wire, and is pressed against the conical shaped opening provided on the end plug. The welding method avoids contaminating the weld with undesirable impurities from the electrode material, and the welding operations is designed so that there is no need to reshape the end of the electrode or adjust the gap between the sealing material and the seal opening.

Abstract: A welding apparatus for welding an end plug on the end of a pellet filled nuclear fuel rod includes a holding mechanism, an abutting member, a torch and a pressing mechanism. The holding mechanism is for holding the external periphery of the fuel rod with the end plug attached thereto. The abutting member is disposed opposite to the holding mechanism, and the end plug of the fuel rod butts up against the abutting member. The torch is disposed between the holding mechanism and the abutting member, and is placed diametrically opposite to the external surface of the fuel rod. The holding mechanism and the abutting member are made so that the distance therebetween can be adjusted, and the pressing mechanism is provided on one of the holding mechanism or the abutting member, and operates to move the holding mechanism and the abutting member to approach each other.

Abstract: In a printer, a unit for turning over a sheet comprises: a conveying roll provided downstream of a printer head; a top roll and a bottom roll which are rotatably coupled to the front end and the rear end of a swingable link, respectively; and at least one elastic endless belt reeved around the top roll and bottom roll, the swingable link being swingable about the axis of the top roll with the top roll into contact with the conveying roll through the endless belt, and a control mechanism for operating the link so that it is swung down for a first half of a period of time for which a sheet passes through the conveying roll and the top roll, and swung up for the second half.