Aluminum alloy reactor

Reactor. Figure 1 shows a cross-sectional view of the aluminum alloy reactor. The rotating cylinder, 7, is 18 in. long by 10 in. diara., and the annular space, 6, (approx. 0.3 in. wide) is uniformly filled with a 0.75% Pt on AI2O3 reforming catalyst crushed and graded up to 40 to 60 mesh. Circular Teflon rings, 4,... 

BORON TRDXUORIDE. BF). Aluminum alloy reactors have been used in the manufacture of naphthalene in which boron trifluoride is used as a catalyst. See also Ref (1) p. 127, (3) p. 51, (7) p. 37. 

Catalytic methanation processes include (/) fixed or fluidized catalyst-bed reactors where temperature rise is controlled by heat exchange or by direct cooling using product gas recycle (2) through wall-cooled reactor where temperature is controlled by heat removal through the walls of catalyst-filled tubes (J) tube-wall reactors where a nickel—aluminum alloy is flame-sprayed and treated to form a Raney-nickel catalyst bonded to the reactor tube heat-exchange surface and (4) slurry or Hquid-phase (oil) methanation. 

The fifth component is the stmcture, a material selected for weak absorption for neutrons, and having adequate strength and resistance to corrosion. In thermal reactors, uranium oxide pellets are held and supported by metal tubes, called the cladding. The cladding is composed of zirconium, in the form of an alloy called Zircaloy. Some early reactors used aluminum fast reactors use stainless steel. Additional hardware is required to hold the bundles of fuel rods within a fuel assembly and to support the assembhes that are inserted and removed from the reactor core. Stainless steel is commonly used for such hardware. If the reactor is operated at high temperature and pressure, a thick-walled steel reactor vessel is needed. 

It is important to note safety differences between the SRS reactors and LWRs. Since the SRS reactors are not for power production they operate at a maximum temperature of 90° C and about 200 psi pressure. Thus, there are no concerns with steam blowdown, turbine trip, or other scenarios related to the high temperature and pressure aspects of an LWR. On the of nd, uranium-aluminum alloy fuel clad with aluminum for the SRS reactors melts at a m ver... 

The reactor can be obtained in many materials such as aluminum alloys, copper, silver, titanium and stainless steel. The number of stacked platelets, the dimensions of the micro channels on the platelets and the fluidic connectors were also varied. Pressure tightness up to 25 bar and He tightness were demonstrated, although this is certainly not the upper limit. 

GP 2] [R 3a] The performance of one micro reactor with three kinds of catalyst -construction material silver, sputtered silver (dense) on aluminum alloy (AlMg3), and sputtered silver on anodically oxidized (porous) aluminum alloy (AlMg3) -was compared with three fixed beds with the same catalysts [44]. The fixed beds were built up by hackled silver foils, aluminum wires (silver sputtered) and hack-led aluminum foils (anodically oxidized and silver sputtered), all having the same catalytic surface area as the micro channels. Results were compared at the same flow rate per unit surface area. 

The excess aluminum in the charge compensates for the loss of aluminum due to nonreductive air oxidation, and also provides aluminum for alloying with the niobium metal produced in the reduction. As mentioned earlier, the liquidus temperatures of niobium-aluminum alloys are lower than the melting point of niobium. The melting of this alloy and the alumina slag is achieved even with the reduced amount of heat available from the reaction implemented without preheating in the open reactor. 

For the elucidation of chemical reaction mechanisms, in-situ NMR spectroscopy is an established technique. For investigations at high pressure either sample tubes from sapphire [3] or metallic reactors [4] permitting high pressures and elevated temperatures are used. The latter represent autoclaves, typically machined from copper-beryllium or titanium-aluminum alloys. An earlier version thereof employs separate torus-shaped coils that are imbedded into these reactors permitting in-situ probing of the reactions within their interior. However, in this case certain drawbacks of this concept limit the filling factor of such NMR probes consequently, their sensitivity is relatively low, and so is their resolution. As a superior alternative, the metallic reactor itself may function as the resonator of the NMR probe, in which case no additional coils are required. In this way gas/liquid reactions or reactions within supercritical fluids can be studied... 

A study of the pretreatment application and the surface prior to deposition indicates that the aluminum alloy panels have a marked sensitivity to the buildup of a fluorocarbon background in the plasma reactor. This study also showed that the application of the O2 plasma treatment modified the alloy surface, changing it... 

The DC cathodic polymerization, 40-kHz (HF) and 13.5-MHz (RF) plasma polymerization of trimethylsilane (TMS) were compared in a bell jar type of reactor [1-3]. The bell jar has the dimensions of 635 mm height and 378 mm diameter. A pair of stainless steel plates (17.8 x 17.8 x 0.16cm) was placed inside the bell jar with spacing of 100 mm and used as parallel electrodes. The substrate used in the plasma deposition process was an aluminum alloy panel positioned in the midway between the two parallel electrodes. 

Fumeaux et al. [1987] used porous alumina membrane reactors to hydrogenate ethene to form ethane at 200X with Ft or Os as the catalyst impregnated in the alumina membranes. Conversion to ethane was detected but no data was provided. Suzuki [1987] tested porous stainless steel and nickel-aluminum alloys as membrane reactors for hydrogenation reactions. Hydrogenation of 2-butenc with stainless steel as the membrane... 

Origins. Most of the radioactive waste at SRP originates in the two separations plants, although some waste is produced in the reactor areas, laboratories, and peripheral installations. The principal processes used in the separations plants have been the Purex and the HM processes, but others have been used to process a variety of fuel and target elements. The Purex process recovers and purifies uranium and plutonium from neutron-irradiated natural uranium. The HM process recovers enriched uranium from uranium—aluminum alloys used as fuel in SRP reactors. Other processes that have been used include recovery of and thorium (from neutron-irradiated thorium), recovery of Np and Pu, separation of higher actinide elements from irradiated plutonium, and recovery of enriched uranium from stainless-steel-clad fuel elements from power reactors. Each of these processes produces a characteristic waste. 

The French transplutonium elements production program (essentially 21+3Am and 2l+,+ Cm) is based on the treatment of plutonium-aluminum alloy targets irradiated in the Celestin reactors at Mar-coule. At the time of chemical treatment, these targets (which initially contained approximately 400 g of 239Pu) contain 44 g of 21+2Pu, 8.5 g of 2l+3Am, 7.5 g of 2l+,+Cm, and about 340 g of fission products, including - 240 g of lanthanides, chiefly the elements La, Ce and Nd (J). 

The Idaho Chemical Processing Plant is a versatile, multipurpose facility used for recovering highly enriched uranium from a variety of fuels in naval propulsion, research, and test reactors. Materials processed [Al] include aluminum-alloyed, zirconium-alloyed, stainless steel-based, and graphite-based fuels. The West Valley plant, although designed primarily for low-enriched uranium fuel from power reactors, also processed plutonium-enriched and thorium-based fuels. It is the only U.S. plant to have reprocessed fuel from commercial nuclear power plants. 

USE Source of neutrons when bombarded with alpha particles according to the equation jBe + JHe J C + jn This yields about 30 neutrons per million alpha particles. Also as neutron reflector and neutron moderator in nuclear reactors. In beryllium copper and beryllium aluminum alloys (by direct reduction of beryllium oxide with carbon in the presence of Cu nr Al). In radio tube parts. In aerospace structures. In inertial guidance systems. 

Tc is available through the /l -decay of Mo (Fig. 2.1.B), which can be obtained by irradiation of natural molybdenum or enriched Mo with thermal neutrons in a nuclear reactor. The cross section of the reaction Mo(nih,v) Mo is 0.13 barn [1.5], Molybdenum trioxide, ammonium molybdate or molybdenum metal are used as targets. This so-called (n,7)-molybdenum-99 is obtained in high nuclidic purity. However, its specific activity amounts to only a few Ci per gram. In contrast, Mo with a specific activity of more than in Ci (3.7 10 MBq) per gram is obtainable by fission of with thermal neutrons in a fission yield of 6.1 atom % [16]. Natural or -enriched uranium, in the form of metal, uranium-aluminum alloys or uranium dioxide, is used for the fission. The isolation of Mo requires many separation steps, particularly for the separation of other fission products and transuranium elements that arc also produced. 

The reactor is atwo-liter Erlenmeyerflaskequipped with a thermometer and a stainless steel stirrer. This flask is chained with 160 g. of NaOH and 600 ml. of water. The solid is dissolved with intensive stirring and the solution is cooled in an ice bath to 50°C. Then, 150 g. of Raney nickel-aluminum alloy (1 1) is added in small pieces. The rate of addition should be such that the temperature of the mixture remains constsnt at 50 2°C. The addition takes 20-30 minutes. The solution is then stirred for an additional 50 minutes while the temperature is kept at 50°C (first by cooling and later by heating on a water bath). The catalyst sludge product is washed three times by decantation with water. It is immediately placed in the washing tube c of the apparatus in Fig. 337 (the last of the product is transferred into c with a stream of water from a wash bottle). 

The Eurochemic reprocessing plant, erected by a consortium of 13 European member states of the OECD/NEA, was in active operation between 1966 and 1974. During these campaigns, 181.5 tons of natural and slightly enriched uranium fuels and 30.6 tons of highly enriched aluminum alloy fuels from material testing reactors were reprocessed. 

The reactor tank from top.plug to bottom plug was identical to the actual reactor design of that date except for the substitution of Amercoat-covered mild steel for stainless steel at tauk sections A,. B, E, and F. The top plug was equipped with two safety rods and one regulating-rod drive. All bearings, grids, etc. were supplied, for the aluminum tank section. The reflector was made of aluminum, as already mentioned, and the " fuel" was fabricated as uranium-aluminum alloy. 

HOWELL, IP, Corrosion of aluminum alloys in a reactor disassembly basin , Corrosion/93, Natl Assoc, of Corrosion Engineers, Houston, TX (1993) paper 609. 

Corrosion of aluminum-clad reactor fiiel and target alloys in the Disassembly Basins is bdieved to be caused by a number of foctors which are operating at the same time. The most important of these factors are ... 

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