摘要:
A spacer includes a plurality of ferrules welded to one another to form a structural integral matrix for locating fuel rods in a fuel bundle. Each ferrule has a pair of stops along one side of the ferrule and a central opening along its opposite side. An elongated flat spring having openings straddling a central cross-piece is disposed along an outer edge of the ferrule with the spring openings receiving band portions of the ferrule above and below the opening through the ferrule. The intermediate cross-piece bears against an adjoining ferrule whereby the end portions of the spring bear against the rod in the one ferrule, biasing it against the opposite stops. Thus ferrule/spring construction reduces the quantity of material of the ferrule, thereby improving performance without sacrificing structural integrity.
摘要:
In the automated production line manufacture of nuclear fuel bundle spacers, rod-supporting ferrules are cut from tubular stock, checked for length, laser cut to create predetermined features in the ferrule sidewall, formed with rod-centering stops in the ferrule sidewall, and checked for stop height dimensional accuracy. Pairs of ferrules are subassembled with a captive spring and assembled into a spacer assembly fixture together with other spacer parts. The fixtured spacer parts are conjoined by laser welding to create a structurally rigid spacer. The various production line operating stations are served by separate controllers linked to a central computer for production status reporting, parts traceability, and overall control purposes.
摘要:
To form longitudinally spaced pairs of angularly spaced stops in the walls of fuel rod-positioning ferrules utilized in nuclear fuel bundle spacers, the ferrules, cut from tubular stock, are longitudinal oriented in a first station and angularly oriented in a second station using a reference notch cut in one ferrule edge. Successive ferrules are picked from the second station and placed in a die of a punch press. Ferrule exterior surface back-up is provided by the die upon closure, and interior surface back-up is provided by a mandrel inserted in the ferrule bore as the punches converge into stop-forming engagement with the ferrule wall. Formed ferrule discharge is induced by placement of the next ferrule in the die.
摘要:
Tubular parts are delivered in successive pairs to separate rotary positioners where they are held for machining in parallel by twin laser cutting beams directed thereat by a commonly mounted pair of focussing heads. The rotary positioners are commonly rotated through a programmed series of angular motions in conjunction with a programmed series of joint X and Y axes linear motions of the focusing heads to scan the cutting beam over the surfaces of the parts and thus machine identical feature cuts in the sidewall of each part. Machining is performed under an inert gas atmosphere, and cuttings are vacuumed from the machining sites through apertured mandrels inserted into the part bores.