Future nuclear power plants like the very high temperature reactor or the gas cooled fast reactor need materials able to comply with extreme operating conditions (temperature, cooling gas, radiation). Advanced materials like oxide dispersion strengthened (ferritic) steels (ODS) or intermetallics are considered as candidates for such plants. The ferritic ODS alloy PM 2000 and a creep resistant TiAl intermetallic were He-implanted at different temperatures. Swelling behaviour as well as damage development were studied. Irradiation induced creep was investigated for TiAl at temperatures of 350°C and 500°C.