Lithium For The Breeding Blanket

Tritium is bred when blanket lithium absorbs fusion neutrons; lithium is abundant, widely distributed, and used in modest quantities per plant.

Lithium is the breeding feedstock

The breeding blanket that surrounds the plasma contains lithium. When a 14 MeV fusion neutron strikes a lithium nucleus, the reaction produces tritium (plus helium). This is the mechanism that lets a deuterium-tritium plant manufacture its own fuel. Lithium, together with deuterium from water, is one of only two consumable inputs to the closed cycle.

Abundance and distribution

Lithium is a common element found in brines and mineral deposits on every inhabited continent, and it is already produced at large industrial scale. The amount a fusion blanket consumes to breed a year of tritium is small compared with global lithium production, and it is not in direct competition with the far larger tonnages used elsewhere.

• Lithium occurs in brines and ores across many regions
• Blanket consumption per plant is modest
• Both natural lithium isotopes participate in breeding reactions
• Lithium can be recovered and recycled within the blanket system

A widely distributed input

Because lithium is geographically dispersed and the quantities are small, it does not reintroduce the supply concentration that fusion is meant to escape. See lithium-6 versus lithium-7 and lithium recycling in the blanket.

A small, dispersed second input

Lithium is the only mined material the fuel cycle depends on, and it enters in small, recyclable quantities from sources spread across many regions. This keeps the cycle from quietly reintroducing the supply concentration that fusion is meant to escape, and it means the blanket does not compete meaningfully with the far larger lithium demands of other industries. The second input is as benign, in supply terms, as the first.