Dragon Project Metals Corrosion Programme Description of the Helium Rig at CIIR Oslo

The early metal/gas corrosion studies carried out at CIIR Oslo were to study the behaviour of a limited range of alloys under a series of gas compositions which would be applicable to the partial pressures of the primary coolant impurities which could be met in an HTR system. As this early work was carried out with no carrier gas and no stress it was thought that a truer picture of the corrosion phenomena would be seen if helium was used as the carrier gas for the impurities, and the alloys under test were subjected to a stress level some orders of magnitude larger than that they would see under normal working conditions. To redirect these studies it has been necessary to build a helium loop and furnace rig at CIIR where materials can be stressed at high temperatures, and deliver gas of controlled compositions to the furnaces at such a rate that the gaseous equilibrium are not affected by the corrosion rate of a large number of specimens. To this end a rig has been built at CIIR Oslo based on graphite corrosion loops developed at Dragon.