AbstractThe long-term activation behavior of the martensitic–ferritic steel Eurofer 97 as structural material for fusion reactors has been investigated on the basis of activation calculations for the European Union (EU) helium-cooled pebble bed (HCPB) outboard DEMO blanket. Activation calculations were performed with the FISPACT-97 inventory code and EAF-97 activation cross-section data for three representative positions at the outboard first wall, the central part and the back wall of the EU-HCPB DEMO blanket. All stable elements were taken into account as impurity elements. Radial dependent values and blanket averages were derived for the permissible impurity element concentrations to arrive at an Eurofer 97 gamma dose rate below the hands-on level after a cooling time of 200 years.