In a future fusion power plant the plasma-facing surfaces will presumably be protected with tungsten. Material erosion by high-energy hydrogen is kept low by this robust metal. This, however, constitutes a disadvantage to the safety properties of the power plant. Like other wall materials, tungsten is activated by the fast fusion neutrons. In the event of a loss of cooling the surfaces can heat up to more than 1100° C due to afterheat. Air ingress causes formation of tungsten oxide, which is volatile at high temperatures.
The positive safety features of a power plant are maintained in spite of this effect. Nevertheless, it is desirable to suppress oxidation and evaporation of the radioactive material. For this purpose IPP is developing tungsten alloys which are self-passivating.