AbstractInvestigations into the radiogenic helium effect on mechanical properties and structure of the Pd-alloy B-1 have been carried out. For accelerated accumulation of helium in the alloy up to 3190 appm (simulating a long-term permeator operation (∼6 years) when cleaning up the international thermonuclear experimental reactors (ITER) spent D–T fuel mix) the alloy was saturated with tritium at room temperature. High tritium solubility was thus achieved at relatively low pressures. Research results showed that radiogenic helium available in the specimens causes their hardening with significant decrease in plasticity. Structural changes in the specimen material have not been found.