Liquid metals containment system

Metal-Containing Systems Many of the systems studied are based on the [MQ4p anion. Neve et al. have studied extensively the formation of liquid crystalline phases on N-alkylpyridinium salts vyith alkyl chain lengths of re = 12-18 vyith tetrahalomet-allate anions based upon Pd(II) [27], Cu(II) [28], Co(II), Ni(ll), Zn(II) and Cd(II)... 

Several fluid-fueled reactors have been built and operated as experiments. The concept is that fuel is contained within the coolant. Systems of this type include aqueous fuel systems, liquid metal-fueled systems, molten salt systems, and gaseous suspension systems. The homogeneous reactor experiment was constructed and operated at Oak Ridge Nahonal Laboratory, as was the Molten-Salt Reactor experiment. A liquid metal fuel reactor experiment was operated at Brookhaven National Laboratory. Power reactors of this type have not been built. 

The environmental boundaries of a liquid metal system are set by the containment material. This material may experience other types of corrosion on the exterior surface (of pipe or tubing for example), but it isolates the liquid metal from interaction with any external atmosphere. This specification of "contained and isolated" sets the limits for the liquid metal corrosion system. Other more genercJ areas of liquid metal/metal interaction, such as that produced when, for example, liquid steel or aluminum come into contact with materials employed in their production, are excluded by this definition. Liquid metal embrittlement will not be addressed. Information on this topic can be found elsewhere [1-3]. 

In systems where a liquid metal is used as the working fluid (e.g., the Rankine-cycle), liquid is converted to vapor in one part of the system and vapor to liquid in another part. The distillation effects of the vaporization process result in extremely pure condensing vapor that may be able to dissolve and transport container material. As opposed to an aU-liquid system, where the liquid is always partially saturated with container material constituents, dissolution in the condenser region can continue undiminished the dissolution rate will depend on the condensation rate and temperature. In contrast, hquid in the evaporator section will ultimately become supersaturated with respect to container material constituents, so that the heated sections of a liquid metal boiUng system will be subject to deposition rather than corrosion [S/]. 

EPR spectroscopic measurements can be performed at high, room or low (>4K) temperature. Samples may be solid (single crystal or powder) or liquid (fluid or frozen solution, a glass ). In this introduction to EPR spectroscopy, we shall be concerned (Mily with magnetically dilute systems in which the unpaired electrons are involved in intramolecular (not intermolecular) interactions. We shall focus attention on the application of the technique to mononuclear, metal-containing systems. 

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). 

Solution of alkali metals in liquid ammonia, containing the so-called solvating electrons, may be used as an alternative homogeneous system to initiate polymerization by an electron transfer process. This system suffers, however, from complications resulting from proton transfer from ammonia leading to the formation of NH2- ions, which in turn initiate further polymerization.4... 

Finally, there are groups of liquid crystals where, at the current time, force fields are not particularly useful. These include most metal-containing liquid crystals. Some attempts have been made to generalise traditional force fields to allow them to cover more of the periodic table [40, 43]. However, many of these attempts are simple extensions of the force fields used for simple organic systems, and do not attempt to take into account the additional strong polarisation effects that occur in many metal-containing liquid crystals, and which strongly influence both molecular structure and intermolecular interactions. 

Nuclear and magneto-hydrodynamic electric power generation systems have been produced on a scale which could lead to industrial production, but to-date technical problems, mainly connected with corrosion of the containing materials, has hampered full-scale development. In the case of nuclear power, the proposed fast reactor, which uses fast neutron fission in a small nuclear fuel element, by comparison with fuel rods in thermal neutron reactors, requires a more rapid heat removal than is possible by water cooling, and a liquid sodium-potassium alloy has been used in the development of a near-industrial generator. The fuel container is a vanadium sheath with a niobium outer cladding, since this has a low fast neutron capture cross-section and a low rate of corrosion by the liquid metal coolant. The liquid metal coolant is transported from the fuel to the turbine generating the electric power in stainless steel... 

---