Modelling of oxidation of W and W-alloys in fusion reactor first walls

Oxidation of tungsten in accident scenarios is a concern for the operation of future fusion reactors.

The formation of volatile WO3 in scenarios where W is exposed to air while hot (circa 1500K) due to radioactive decay could have severe implications for the safe operation of a reactor after accidents, particularly since the WO3, which sublimates readily could be radioactive due to being formed from unstable W isotopes (e.g. 187W and 185W).

The volatility of WO3 will also be a problem during maintenance and decommissioning, where plasma-facing components will be removed from a fusion reactor, exposed to air, and not subject to the same cooling as during operation. An oxide that forms would pose a hazard to workers if it becomes dust.

The aim of this project is to use modelling to develop understanding of how oxidation occurs in W and its alloys, including predictions, validated by experiment, of oxidation rates as a function of temperature that will be crucial to understand for plant operation and maintenance planning.