Cooling liquid metal

Liquid sodium is used to cool liquid-metal fast-breeder nuclear reactors. 

In recent years, liquid metal cooling (LMC) is used as a new process in large blade casting, but it still needs to be improved. Fig. 1 is the schematic of a LMC furnace. In this process, low melting-point metal is used as cooling liquid metal. Instead of radiation, heat convection happens between the cooling liquid metal and the shell below the liquid surface. A new way is needed to find more optimized process by LMC without too many experiments. 

The type of heat transfer at the surface is determined by the value of z. Suppose the height of the cooling liquid metal surface is h, when z>h, the surface element radiates with the furnace wall, a Monte Carlo algorithm is applied to calculate the view factor varying with withdrawal distance. When zfollowing equation is used to calculate the heat transfer ... 

To support the preparation of this and the previous report [2], an IAEA technical meeting Innovative small and medium sized reactors design features, safety approaches and R D trends was held on 7-11 June 2004 in Vienna, and its final report was published as IAEA-TECDOC-1451 in May 2005 [1]. That TECDOC presented a variety of innovative water cooled, gas cooled, liquid metal cooled and non-conventional SMR designs developed worldwide and examined the technology and infrastructure development needs that are common to several concepts or lines of such reactors. It also introduced the definition of small reactors without on-site refuelling, which is referred to in this report. Both, the technical meeting and the report [1] provided recommendations on the objectives, structure, scope and content of this report and the report [2]. 

Annexes I-XXX present the contributions from Member States — structured design descriptions of water cooled, gas cooled, liquid metal cooled, and non-conventional (molten salt cooled, etc.) small reactors without on-site refuelling. 

About 50 concepts and designs of the innovative SMRs are under development in more than 15 IAEA Member States representing both industrialized and developing countries. SMRs are under development for all principle reactor lines, i.e., water cooled, liquid metal cooled, gas cooled, and molten salt cooled reactors, as well as for some non-conventional combinations... 

Innovative SMR designs are under development for water cooled, gas cooled, liquid metal cooled and molten salt cooled reactor lines, as well as some non-conventional combinations thereof The targeted timelines of readiness for deployment vary between 2010 and 2030 the major concerns addressed by the innovation cover a broader spectrum of subject areas as compared to the operating and near term evolutionary NPPs, see Table 1. Such extended consideration is apparently due to the anticipated growth and geographical expansion of nuclear power. 

R. J. Teitel, An Internally Cooled Liquid Metal Fuel Reactor Design, in Proceedings of the First Nuclear Engineering and Science Congress, Vol. 1, Problems in Nuclear Engineering. Now York Pergamon Press, 1957. (pp. 292-301)... 

Fig. 24-4. Two-region, externally cooled liquid metal fuel reactor.

Liquid metals, however, present several disadvantages. Their weights must be considered with regard to equipment design. Additionally, Hquid metals are difficult to contain and special pumps must be used for system safety. Alkali metals react violentiy with water and bum ia air. Liquid metals also may become radioactive whea used for cooling auclear reactors (qv). 

The melt is heated by passing a large elecuical cunent between two electrodes, one of which is tire metal rod to be refined, and the otlrer is the liquid metal pool standing in a water-cooled copper hearth, which collects the metal drops as tlrey fall tluough the molten electrolyte. This pool tlrerefore freezes at the bottom, forming the ingot. Under optimum chcumstances tire product billet takes the form of a cylindrical solid separated from the molten salt by... 

Glasses, like metals, are formed by deformation. Liquid metals have a low viscosity (about the same as that of water), and transform discontinuously to a solid when they are cast and cooled. The viscosity of glasses falls slowly and continuously as they are heated. Viscosity is defined in the way shown in Fig. 19.7. If a shear stress is applied to the hot glass, it shears at a shear strain rate 7. Then the viscosity, ij, is defined by... 

A versatile Laser-SNMS instrument consists of a versatile microfocus ion gun, a sputtering ion gun, a liquid metal ion gun, a pulsed flood electron gun, a resonant laser system consisting of a pulsed Nd YAG laser pumping two dye lasers, a non-resonant laser system consisting of a high-power excimer or Nd YAG laser, a computer-controlled high-resolution sample manipulator on which samples can be cooled or heated, a video and electron imaging system, a vacuum lock for sample introduction, and a TOF mass spectrometer. 

Nickel-manganese-palladium brazes are resistant to attack by molten alkali metals and And applications in sodium-cooled turbine constructions. Their freedom from silver and other elements of high thermal neutron-capture cross-section allows them to be used in liquid-metal-cooled nuclear reactors. 

Other samples examined to date have included mass-transfer inclur s from liquid metal cooling systems, titanium alloy phases, and interm c... 

Many of the techniques available to purify alkali metals were initially developed to use with liquid sodium as a consequence of its large-scale application in liquid-metal-cooled fast-breeder reactors. These techniques can be summarized as filtration or cold trapping distillation or chemical (gettering). 

The conversion process for the copper matte removes iron, sulfur and other impurities from matte, thereby yielding liquid metallic copper of about 99% purity (blister copper). The slags which come out of converters contain from 2 to 15% copper and must go through treatment for copper recovery, usually by froth flotation of the copper from solidified and slowly cooled slag. 

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