ISSN:
1573-4889
Keywords:
Reactor helium
;
carbon activity
;
oxygen activity
;
flow conditions
;
reactions with Pt, Cr, Cr3C2, Cr2O3
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Helium used as a coolant in high-temperature gas-cooled reactors contains gaseous impurities that cause various corrosion effects. To determine the mechanisms of the reactions that occur in this complex gas phase, a theoretical and experimental characterization of the gas is given in part 1. To obtain estimates of the reactions that are possible in principle and to derive the basis for the interpretation of the experimental results, thermodynamic considerations on gas equilibrium and partial equilibria are presented. Because of the extremely low concentrations of the impurities, diffusion processes within the gas may become rate-controlling. This requires a consideration of the flow conditions. The reactions of Pt, Cr, Cr2O3 and Cr3C2 with helium-based atmospheres containing impurities are investigated by means of a mass spectrometric gas analysis with respect to temperature and flow rate. A set of six reactions is derived from the results and discussed in detail. The application of these equations to describe the high-temperature corrosion phenomena of a technical nickel-base alloy is dealt with in part 2.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00656642
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