Fusion blankets include lead or beryllium as neutron multipliers. When a nucleus of either is hit with a neutron, it releases two more. The resulting neutrons c

Fusion blankets include lead or beryllium as neutron multipliers. When a nucleus of either is hit with a neutron, it releases two more. The resulting neutrons can still breed tritium from lithium. CFS for example uses beryllium in a FLiBe salt. General Fusion and Zap Energy use lead.