Aluminum cladding

The clad plate is x-rayed perpendicular from the steel side and the film contacts the aluminum. Radiography reveals the wavy interface of explosion-welded, aluminum-clad steel as uniformly spaced, light and dark lines with a frequency of one to three lines per centimeter. The waves characterize a strong and ductile transition joint and represent the acceptable condition. The clad is interpreted to be nonbonded when the x-ray shows complete loss of the wavy interface (see X-ray technology). 

A number of pool, also called swimming pool, reactors have been built at educational institutions and research laboratories. The core in these reactors is located at the bottom of a large pool of water, 6 m deep, suspended from a bridge. The water serves as moderator, coolant, and shield. An example is the Lord nuclear reactor at the University of Michigan, started in 1957. The core is composed of fuel elements, each having 18 aluminum-clad plates of 20% enriched uranium. It operates at 2 MW, giving a thermal flux of 3 x 10 (cm -s). The reactor operates almost continuously, using a variety of beam tubes, for research purposes. 

Aluminum and aluminum-clad steels am highly resistant to naphthenic acids under most conditions. Aluminum-coated steels give good service until coatings fail at coating imperfections, cracks, welds, or other voids. In general, the use of aluminum and aluminized... 

Some of the restrictions on the use of aluminum are caused by manufacturing and fabrication problems and by its low mechanical strength. However, aluminum is widely used and is competitive with Type 316 stainless steel in many instances. The explosion-bonding process has made the aluminum cladding of steel practical, and... 

Clad metals are candidates for galvanic corrosion along exposed edges. An example is copper/aluminum clad to aluminum. 

Earlier reactors at this site used aluminum clad because it dissolves in sodium hydroxide. 

A.17 Spacecraft are commonly clad with aluminum to provide shielding from radiation. Adequate shielding requires that the cladding provide 20. g of aluminum per square centimeter. How thick does the aluminum cladding need to be to provide adequate shielding ... 

Shuck, A. B. The Manufacture of Aluminum-Clad Aluminum-Plutonium... 

Aluminum cladding is an alloying process used to help prevent surface corrosion of other underlying metal components. This process involves hot rolling metal to produce a protective aluminum barrier. Clad aluminum alloys can be found in some heat exchanger tubing applications. 

The target island contains 31 positions for the aluminum-clad target assemblies. As presently operated, the target in the centerline position is replaced with a versatile hydraulic rabbit facility, which gives ready access to the position of... 

Plutonium-239 and tritium for use as military explosives are the two major transmutation products. The nuclear process for Pu-239 production is the same as for energy generation, but there are some differences (a) metallic natural uranium clad with aluminum facilitates later dissolution for plutonium recovery, and the reactor operates at a relatively low temperature because of the aluminum clad and better heat transfer (due to the metallic natural uranium) (b) the irradiation cycle is limited to a few months to minimize the Pu-239 conversion to Pu-240 and Pu-241 and (c) a carbon or a heavy water moderator is used to increase the neutron efficiency. 

Uranium fuel preparation takes the UF6 and is converted to either (a) aluminum-clad uranium metal for the weapons plutonium production reactors or (b) to Zirconium-clad U02 for electricity production in the light and heavy water power reactor (see Fig. 21.13). 

The whole apparatus, which was 10 cm tall, was mounted on a goniometer head, this being fixed to the 0-tumtable of the diffractometer. This arrangement allowed the sample to be exactly located at the center of rotation of the diffractometer. The body of the cell holder was of aluminum, clad in cadmium foil. The sample and solution were cooled using the water circulation ports illustrated, the temperature within the cell being monitored by means of a metal junction thermometer. 

An ideal model system was selected to study the interfacial factors with EIS [19]. The model system was Parylene C-coated Alclad (aluminum-clad aluminum alloy). In this system, the surface state of the top surface (salt solution/coating interface) and the adhesion of the coating (coating/metal interface) were modified to study the influence of these factors on the corrosion protection performance of the system. 

Ymra and Yi are obtained from the relations y = 0,44y and y, = 16,3y , where y is the averaged volume weight of the foam block. The compaction gradient is 2.0 for asbestos cement and 0.70 for aluminum cladding layers. The calculated and experimental Ay distribution curves are in good agreement (Fig. 7). 

Columns of aluminum-clad fused silica [2,4] and metal-clad fused silica support temperatures up to 500°C, representing an advantage in comparison with borosilicate glass columns, with a temperature limit to 450°C, and columns of polyimide-clad fused silica for high temperature [2,9], limited temperature to 400-420°C. On the other hand, aluminum-clad fused silica columns present leakage, principally in the connec-... 

The thermal stability of the stationary phase is also important. Because each stationary phase has a range of thermal stability, it is important to control column temperature within the specified range. For the nonpolar phases, the temperature limit is determined by the stability of the poly-imide coating. The introduction of aluminum clad columns notably broadens the useable temperature range. Oxidation at higher temperatures limits the operating temperature of intermediate to polar phases. 

The aluminum cladding was removed and the fuel elements dissolved in nitric acid and treated with NaNOi to reduce the plutonium to Pu". Sulfuric acid was added to complex the uranyl nitrate to prevent it from precipitating with the plutonium. The BiP04 precipitate carried essentially all the plutonium while most of the fission products and the U remained in solution in this extraction step. The centrifuged precipitate was dissolved in nitric acid and NaBiOs added as an oxidant and a source of bismuth. The oxidized plutonium, Pu +, remains soluble and the fission products carried by the BiP04 precipitate were removed. 

Jackson and Walser [Jl] have given a detailed description of the operations conducted in 1970 by the Atlantic Richfield Hanford Company to separate and decontaminate and its associated thorium from aluminum-clad thorium dioxide irradiated to low burnup in the Hanford reactors. 

Dissolution. The aluminum cladding was dissolved in a solution of mixed sodium nitrate and sodium hydroxide, and the undissolved uranium, thorium, and fission-product oxides were separated by filtration and centrifugation. The oxides, together with some adherent sodium hydroxide, sodium nitrate, and sodium aluminate, were dissolved in a mixture of boiling 13 M nitric acid, aluminum nitrate, and potassium fluoride. From 16 to 48 h were required for dissolution. After dissolution was complete, the composition of the solution was as given in the first column of Table 10.17. 

LtPSKY, S. R. Duffy, M. L. 1986a. High temperature gas chromatography the development of new aluminum clad flexible fused silica glass capillary columns coated with thermostable nonpolar phases Part 1. Journal of High Resolution Chromatography, 9, 376-382. 

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