Tritium Inventory as a Materials Problem
Tritium permeates hot metals and is held up in materials; managing where it goes is a materials-and-chemistry safety problem, not just plumbing.
Tritium goes into materials
Tritium is a small, mobile hydrogen isotope that permeates through hot metal walls and is retained in structural and plasma-facing materials. This makes the machine's tritium inventory partly a materials problem: how much soaks into components, how much permeates toward coolant or environment, and how quickly it can be recovered all depend on material choice and temperature.
Barriers and recovery
- Hot metals permeate tritium; barriers slow the loss.
- Materials retain tritium, adding to inventory and eventual waste.
- Permeation barriers and coatings reduce migration.
- Fast recovery keeps the mobile inventory small.
Why low inventory is the goal
A small mobile tritium inventory reduces both breeding losses and the source term in any incident, which improves the safety case. Achieving it means choosing materials and temperatures that minimize uptake and permeation, and recovering tritium continuously. Inventory management is thus a materials, chemistry, and safety problem at once.
Scope
This page treats tritium inventory as a materials and safety quantity, with no economics. It connects the blanket's tritium extraction, the machine's material choices, and the licensing safety case into one consistent, honestly-stated picture.
Permeation barriers
Coatings and permeation-barrier layers on hot surfaces slow tritium migration into coolant and toward the environment, reducing both loss and the safety source term. Barriers degrade under irradiation and thermal cycling, so their durability is itself a materials question, and the design does not assume a permanent barrier but plans for its maintenance.
This page documents a design and simulation study, not a built machine. Construction begins Q2 2027; first-of-a-kind first tritium is targeted near 2030. Figures are computed, reproducible targets, not measurements.