Tritium

A radioactive hydrogen isotope, bred in the breeder blanket rather than mined.

Tritium is a hydrogen isotope with two neutrons, radioactive with a ~12-year half-life and essentially absent in nature. A D–T plant must breed it; HYPERION's blanket targets 4.0 kg/yr at breeding ratio 1.8.

Tritium is a low-energy beta emitter with a ~12-year half-life, hazardous mainly if inhaled or ingested and essentially absent in nature. The breeder makes its own — 4.0 kg/yr/yr at breeding ratio 1.8 — managed with low inventories, permeation barriers and continuous monitoring, which turns the tritium-supply problem into a feature.