Sodium oxide thermal conductivity

Based on the discussion of the previous section, we would also expect that structural complexity and disorder present in glasses would tend to decrease the thermal conductivity. This is true, especially when alkalis are added to sodium silicate glasses. Figure 4.32 shows the effect of replacing SiOa in Na20-Si02 glass with other oxides. 

The first ferritic oxide dispersion-strengthened (ODS) alloys were developed by SCK CEN, in the 1960s in the frame of the sodium-cooled fast breeders [1], Compared to austenitic alloys, ferritic/martensitic materials display a higher thermal conductivity, a lower thermal expansion, and a lower tendency to He-embrittlemenL They also exhibit a lower swelling as illustrated in Fig. 10.1 [2]. Creep properties of conventional ferritic/martensitic (F-M) alloys are not sufficient to withstand the levels of mechanical loading reached in some core structures. For example, at the end of life, for sodium-cooled fast reactors (SFRs), the internal pressure in the cladding tubes could reach... 

Some unsaturated ketones derived from acetone can undergo base- or acid-catalyzed exothermic thermal decomposition at temperatures under 200°C. Experiments conducted under adiabatic conditions (2) indicate that mesityl oxide decomposes at 96°C in the presence of 5 wt % of aqueous sodium hydroxide (20%), and that phorone undergoes decomposition at 180°C in the presence of 1000 ppm iron. The decomposition products from these reactions are endothermic hydrolysis and cleavage back to acetone, and exothermic aldol reactions to heavy residues. 

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