Measurement and analysis of radioactivity induced in yttrium and lead in fusion peak neutron field

Yttrium is an element in oxide dispersion strengthened (ODS) steels to be used as structural material at high neutron doses and temperatures. Lead acts as a neutron multiplier and coolant in breeding blanket concepts such as the EU test blanket modules (TBM) with Pb–17Li. Samples of pure Y and Pb were irradiated with D–T fusion neutrons. The radioactivity following irradiation was determined several times during decay by γ-spectroscopy. The results were analysed with the European Activation System. Ratios of calculated-to-experimental values for individual activities are discussed in connection with the expected activation performance of the materials in fusion power plant conditions.