摘要:
A fuel assembly in which the fuel rods are arranged in a hexagonal or square, regular pattern, but in which single rods are omitted systematically and deflectors substituted therefor, each deflector normally being situated in a duct, the partition of which consists of six or eight fuel rods, respectively. The deflectors are rigidly connected to grids between the fuel rods so that the rods may expand freely in the grids.
摘要:
A device for guiding and supporting a rod-shaped body which is advanced longitudinally through the device and which has a circular cross-section. The device comprises an outer sleeve and an inner sleeve, which is axially movable with a tight fit in the outer sleeve and is formed at one end with an internal cylindrical surface for engaging the rod-shaped body. The cylindrical surface is provided by a plurality of tongues formed by incisions in the end portion of the sleeve. At the same end the inner and outer sleeves have cooperating inclined contact surfaces, which preferably are conical with different vertical angles, and spring means are provided between the sleeves for effecting a resilient engagement between the inclined contact surfaces of the sleeves and between the internal surfaces of the tongues and the rod-shaped body. The number of tongues is preferably an odd multiple of three.
摘要:
When mapping out the internal cross-sectional dimensions of elongated, tubular bodies, correlated values of the external cross-sectional dimensions and wall thicknesses are measured along measuring lines from the outside of the body and the sum of the wall thicknesses measured along each measuring line is subtracted from the external cross-sectional dimension measured along the same or substantially the same measuring line. This avoids the use of measuring means in the interior of the tubular bodies, whereby the measuring can be carried out much faster and without the danger of injuring the internal surface of the bodies.
摘要:
A method of producing dispersion-strengthened zirconium products containing fine particles of yttria, magnesia, cerium oxide or beryllium oxide in a matrix of zirconium or a zirconium alloy. Preferred products are such containing dispersed fine particles of yttria. In the method hydrided zirconium or zirconium alloy in a manner known per se is in a pulverulent state mixed with a fine powder of the oxide, and the mixture is then heated in vacuum with a view to expel hydrogen. Simultaneously or subsequently, the mixture is - in a compressed condition - sintered. This heating operation for expelling hydrogen and sintering the mixture is carried out at a temperature below 800*C, and preferably below 750*C. Prefered dispersion-strengthened zirconium products are characterized by having the metal oxide particles, of an average size not substantially exceeding 0,5 Mu and preferably between 0,01 and 0,5 Mu , dispersed in the said matrix having an average particle size not exceeding 5 Mu and preferably between 1 and 3 Mu .