Development of a new solid tritium breeder blanket

A future power station will employ the fusion of deuterium and tritium, as it requires the lowest temperature to achieve ignition.

Deuterium is abundant; however, tritium is only generated in nature at a rate of 0.41 kg per year and has a 12.6-year half-life making it extremely rare.

With a 1 GW fusion reactor expected to require ~100 kg of tritium annually, it is essential that we identify a sustainable supply.

Fortunately, tritium can be bred from the transmutation of lithium driven by absorption of the neutron ejected by the D-T reaction. Demonstration of a sustainable tritium cycle is one of the major outstanding engineering challenges facing fusion.

Current blanket concepts were conceived during the design of ITER and use either Li ceramic pebbles or a liquid lithium lead eutectic. The solid tritium-breeding concepts utilise either lithium orthosilicate or lithium metatitanate pebbles.

Both materials have issues, however; the silicate has a low crush strength, which could result in pebble fragmentation, and there is concern about whether the titanate offers a sufficiently high tritium breeding ratio.

Further, current solid breeder concepts employ beryllium as a neutron multiplier, which is undesirable as it is relatively rare, hazardous to handle, and typically contains trace quantities of uranium that are hard to remove.

Therefore, this project will look to design a new breeder blanket for a compact fusion reactor, that uses a solid breeder material.