Abstract: Zircaloy 2 or 4 strip is heat treated in the beta range, followed by rapid cooling by passing the strip between a first and second roller pair, each roller pair having two oppositely disposed rollers gripping the strip. Each roller pair is connected to a source of an electric current so as to complete an electric circuit including the source, the roller pairs and the strip, which causes heating of the strip to the beta range. The strip is heated at a rate less than 40.degree. C./sec between 750.degree. and 1000.degree. C., held at 1000.degree.-1100.degree. for less than 2 minutes and cooled at a rate of at least 40.degree. C./sec between 1000.degree. C. and 600.degree. C.

Abstract: The present invention relates to a process for the manufacture of zirconium based tubes formed from layers of varying composition. The process consists in preparing the tubular blank which is intended to form the outer layer of the tube by rolling-soldering a sheet, and then in fitting it onto another tubular blank, or core block, of smaller diameter, which is obtained by piercing a small bar, and which may be coated on the inside with a plating, in soldering the ends of said blanks in order to subject the assembly to a treatment of placing it in solution in a beta phase, followed by soaking it in water and drawing it. The invention is used for the production of Duplex or Triplex type tubes with an improvement in the gross weight of zirconium needed to make 1000 kg of useful metal, with good adherence being obtained between the layers of said tube.

Abstract: The invention relates to a process for the production of a neutron absorbing pellet for use in a nuclear reactor control device, comprising the following stages:a) compactable products are prepared incorporating as % by weight electrolytic crystals or chips of Hf and optionally boron carbide powder with a total weight (HF+B.sub.4 C) of 40 to 100%, the Hf:(Hf+B.sub.4 C) ratio being 0.20 to 1 and optionally other metallic elements melting at above 400.degree. C.;b) these products are mixed and compressed in a mould in one or more filling and compression operations until a pellet is obtained with an apparent density higher than 80% of its average density in the solid state;c) a sintering treatment is optionally carried out on said pellet;d) the pellet is or has been extracted from the mould;e) the pellet is optionally ground.

Abstract: A method of making a strip of ZIRCALOY 2 or 4 is disclosed wherein an ingot is worked, roughly shaped into a billet then quenched from the beta range, hot rolled in alpha range, annealed and cold rolled to 0.3 to 0.9 mm. The O and C, in ppm, are selected to satisfy the formula: O.sub.2 <1200-0.75 x C (R) so that a T texture is obtained systematically for thicknesses of at least 0.8 mm. The disclosure also concerns the strips obtained. The method can be applied to obtaining strips of excellent formability for the production of components for nuclear water reactors.

Abstract: A method of obtaining uranium metal from an oxidized uranium compound, characterized in that the oxidized compound is treated with chlorine and carbon at a first stage, to obtain a chloride which is reduced by electrolysis or metallothermy using a reducing metal at a second stage.

Abstract: The subject of the invention is a method of making a clad metal, neutron absorbing element, and the neutron absorbing element produced by preparing compactable metal products comprising (weight %) HF at least 25%, Zr and/or Zr alloys=0 to 75%; Ti and/or Ti alloys=0 to 75%; Hf-ZR alloys containing <55% Zr=0 to 75%; Hf-Ti alloys containing <55% Ti=0 to 75%; neutron absorbing metal elements melting at over 400.degree. C.: <0.2% and other metal elements melting at over 400.degree. C.: 0 to the balance, the balance being less than 5%; introducing at least some of these products into a metal container with an open end; compressing the products in the container, or compressing them before putting them into the container; if necessary repeating the introduction and compression of the products until the container is at least 95% full; and closing the open end of the container by welding on a metal lid or plug and providing an internal vacuum. The element is used, e.g.

Abstract: A method of, and an apparatus for, introducing at least one halide into the bath of cell for dry electrolysis. The method confines a portion of the bath in an annular space and upward motion is imparted to the confined portion of the bath by introduction of a gas and halide into the annular space. The apparatus for carrying out the method consists of two concentric tubes: an inner tube through which the halide and the gas are introduced and which tube is open at its bottom end and which tube has orifices on its lateral wall; and an outer tube which is open at its bottom end, closed at the top end and provided on its lateral wall with apertures situated at a level higher than that of the orifices. The method and apparatus can be applied to the operation and construction of electrolysis baths in which the concentration by weight of the halide and its mean valency must be maintained within a narrow range and be able to be adjusted progressively and precisely.

Abstract: A process for obtaining a plate of zirconium alloy comprising at least one portion of excess thickness of at least 0.5 mm relative to a large adjacent face, the portion having edges with angles equal to 90.degree. to 105.degree. and flanks which are connected without depressions to the large adjacent faces. According to the process, a surface portion of a blank plate located straight above a desired portion of excess thickness is coated with a continuous coating which is resistant to a pickling composition to be used, the coated portion widened beyond the desired portion of excess thickness by 0.5-1.5 times the amount of the excess thickness. The coated blank plate is immersed a plurality of times, without passage of electric current, in a pickling bath comprising HF, an oxidizing agent and water, and having a dissolved Zr content less than 12 g/l and a temperature below 35.degree. C. Each immersion removes less than 0.3 mm of thickness over the portions of the blank plate which are not coated.

Abstract: A diaphragm is disclosed for molten salt bath electrolysis of metal halides, the diaphragm comprising carbon fibers disposed in one plane an in at least one direction, embedded at least partially in a rigid and inert material which can be graphite, carbides, oxides or nitrides. The diaphragm has a porosity between 10% and 60% in the form of apertures of an area between 1 and 50 mm.sup.2.

Abstract: The present invention relates to a cold crucible adapted to be discharged through the bottom. The crucible consists of a conductive wall consisting of a plurality of longitudinal hollow segments which are electrically insulated at least partially from one another and which are by virtue of the longitudinal hollows adapted to be traversed internally by a cooling fluid and which crucible is adapted to be placed inside an inductor and in which the wall is provided in its bottom part with an aperture inside which there is a removable occluding member, formed of segments which member is cooled like the wall of the crucible. The crucible is used in the processing of materials of high purity which can be recovered in the liquid state in a convenient complete and rapid manner.

Abstract: The fuel rod comprises a sheath having an inner tubular layer and an outer surface layer composed of zirconium alloys which differ from each other. The surface layer, whose thickness is between 10 to 25% of the total thickness of the wall of the sheath, is constituted by a zirconium-base alloy containing by weight 0.35 to 0.65% tin, 0.20 to 0.65% iron, 0.09 to 0.16% oxygen and niobium in a proportion of 0.35 to 0.65% or vanadium in a proportion of 0.25 to 0.35%. The inner layer may be constituted by an alloy such as Zircaloy 4 or a zirconium-niobium alloy.

Abstract: The invention relates to an apparatus for the continuous production of a polyvalent metal by electrolysis of a halide of the metal in a bath of at least one melted salt. The apparatus comprises an electrodismutation cell and a prereduction cell in a contiguous configuration sharing a common wall in the form of a grid which is electrically insulated from the cell walls. The electrodismutation cell includes at least one deposition cathode and at least two anodes which are connected to an at least partly direct current. The prereduction cell includes at least one anode and a cathode constituted by the grid, the anode and cathode being separated by a diaphragm and connected to an at least partly direct current power supply. Means are provided to cause bath flow by forced convection through the grid to produce a top-to-bottom movement in the electrodismutation cell and a bottom-to-top movement in the prereduction cell.

Abstract: The invention relates to a tube, bar, sheet or strip resistant both to uniform and nodular corrosion, of a zirconium-base alloy of a composition (% by weight) of Fe 0.1 to 0.35, V 0.07 to 0.4, Q 0.05 to 0.3, Sn below 0.25, Nb below 0.25, trace impurities and balance Zr. The invention also relates to a process for producing these products which have a greatly increased service life. It also relates to composite tube having an internal and/or external alloy sheathing.

Abstract: The invention relates to a process and apparatus for the pumping and metering of liquid products, wherein the melting point is between 200.degree. and 350.degree. C. In the process, a pulsation generator with piston and diaphragm displaces a thermal fluid which actuates a pumping apparatus, and the fluid transmits its pulsations to a molten tin alloy or tin bath contained in a siphon, the bath in turn transmitting the pulsations to part of the liquid product to be displaced and which is contained in a conduit connecting the siphon to a diaphragm-free pumping head, between the suction valve and delivery valve of the said pumping head, which makes the latter operate in suction and delivery with respect to the same product between suction pipe and delivery pipe. The process and apparatus are particularly applicable to the pumping of melted salts with a melting point between 200.degree. and 350.degree. C. at temperatures between 210.degree. and 380.degree. C.

Abstract: The invention relates to a process and apparatus for the supply of a Kroll reactor with zirconium tetrachloride vapor, in which zirconium chloride powder is vaporized in a sublimator by heating power and the vapor obtained is passed into the reactor. Part of the heating power applied in the sublimator is supplied to the powder by an internal heating means, and the remainder of the heating power is supplied to the wall of the sublimator by an external heating means. The heating power of the internal heating means is used for the sublimation of the zirconium tetrachloride powder and the heating power of the external means is applied in order to compensate the heat losses of the wall of the sublimator.

Abstract: The process and the device according to the invention relate to the introduction, at a stable, known flow rate, of sublimable tetrachloride into a column for continuous extractive distillation under pressure of the chlorides. The sublimable tetrachloride is dissolved in a hot dissolver in a liquid solvent such as KAlCl.sub.4, and is then recirculated by pump at a stable, known flow rate into an evaporator connected to the column. The solution is then heated in an evaporator in order to sublime the majority of the product which it contains, the sublimed vapors thus passing into the column at a stable, known flow rate. The process according to the invention is adapted, in particular, to a plant for the production of ArCl.sub.4 of nulear purity and of HfCl.sub.4.

Abstract: The invention concerns a process for the production of metal Zr by means of molten Mg in a reactor 1 having a hearth plate 3, comprising separating the magnesium chloride formed in the reduction reaction from the metal Zr formed. The process is characterized by separating the magnesium chloride formed by tapping off towards the bottom of the reactor 1 by means of a chimney 6 whose bottom end portion 5 is fixed to an orifice 4 in the hearth plate 3 and whose transverse open top end 7 is above the portion of the metallic mass Zr, Mg which borders the chimney 6 at the end of the reduction reaction. The invention also concerns the corresponding apparatus for the production of metal zirconium. The invention provides a simplification in the operation of separating the MgCl.sub.2 formed and possibly, by virtue of a particular structure of the chimney according to the invention, gives an improvement in the operation of extracting the sponge cake produced.

Abstract: The invention concerns a process for the production of a strip of Zircaloy 2 or 4 with an oxygen content of between 900 and 1600 ppm and with mechanical characteristics corresponding to the following conditions:E.sub.0.2 at 315.degree. C..gtoreq.250 MPa"long" uniform A% at 20.degree. C..gtoreq.4 and"transverse" uniform A% at 20.degree. C..gtoreq.4,wherein, after hot working of an ingot to provide a billet, said billet is cold rolled to form a strip with intermediate annealing operations, characterized in that: (a) each of the last two intermediate annealing operations is a treatment for from 0.5 min to 10 min at between 750 ad 650.degree. C., (b) the final heat treatment following the last rolling operation is for from 1.5 to 7 min at between 630 ad 590.degree. C., and (c) the strip is rolled with particular degrees of deformation for each of the last three rolling operations.

Abstract: A process is disclosed for improving the ductility of shape-memory alloy products based on Ti-Ni involving martensitic transformation. The process comprises at least one thermal treatment cycle of alternating hot and cold treatment, wherein the first thermal treatment cycle comprises a cold treatment at a temperature both lower than -50.degree. C. and lower than M.sub.s -50.degree. C., where M.sub.s is the temperature at which martensitic transformation of the product begins, and a hot treatment of the product at a temperature of 700.degree. to 900.degree. C. Each optional subsequent thermal treatment cycle comprises a cold treatment of the product at a temperature both lower than -50.degree. C. and lower than M.sub.s -30.degree. C., and a hot treatment of the product at a temperature of 600.degree. to 900.degree. C.

Abstract: A wrought and heat treated titanium alloy part is disclosed having the composition, by w eight, Al 4.5 to 5.4%, Sn 1.8 to 2.5%, Zr 3.5 to 4.8%, Mo 2.0 to 4.5%, Cr 1.5 to 2.5%, Cr+V 1.5 to 4.5%, Fe 0.7 to 1.5%, O 0.07 to 0.13%, the remainder being Ti and impurities. The part is characterized by a fine and regular alpha-beta structure and essentially segregation free microstructures, and has the mechanical characteristics: Rm.gtoreq.1200 MPa, R.sub.p0.2 .gtoreq.1000 MPa, A%.gtoreq.5, K.sub.1c at 20.degree. C..gtoreq.45 MPa..sqroot.m, creep at 400.degree. C. under 600 MPa:0.5% in more than 200 hours.