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The degradation of carbon steels due to corrosion and gaseous permeation phenomena can be significantly reduced by a thin alumina coating. Tubular carbon steel structures, commonly employed in nuclear establishments are particularly vulnerable to chemical degradation on the inner surface due to the flow of corrosive fluids. In the present work, a fluidization-based chemical vapour deposition process is applied as a one-step solution for simultaneous chemical passivation of both inner and outer substrate surfaces meanwhile optimizing precursor inventory by utilizing fluidized bed sublimation and induction heating techniques. The process is studied by using a 2D-1D mathematical model, which has been validated with experimental results for different carbon steel grades. It was observed that there exists an optimum fluidization velocity for a specified initial mass fraction of precursor powder at which mass of alumina deposited per unit mass of precursor sublimated is maximized.

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The fusion of deuterium and tritium is being considered for the energy source from fusion reactions, and on reaction each nuclei will produce one helium nuclei, one neutron and thermal energy. Deuterium is naturally available and the technologies to separate it from the compounds of hydrogen are well developed. Tritium can be produced by nuclear reaction of Li 6 isotope with thermal neutrons, and natural lithium contains about 7.5% Li 6 . Lithium has a low melting point and readily reacts with oxygen, nitrogen and moisture present in air. So, lithium-containing ceramics, namely lithium orthosilicate and lithium titanate enriched in Li 6 isotope, are being considered for tritium production by nuclear reaction with neutron. It was found that like lithium titanate, lithium orthosilicate can also be synthesised and pebbles can be fabricated by solid-state reaction process by using silica and lithium carbonate as raw materials. The advantage of this process is that the synthesis can be carried out at 800°C and fabricated pebbles can be sintered at 900°C to achieve the desired properties of the pebbles. Both these temperatures for synthesis and sintering are lower than that of the molten spray method. The experimental details and results are discussed in this paper.