The stable heavy hydrogen isotope that is one half of the D-T fuel mix — extracted cheaply from seawater in quantities sufficient to power civilisation for billions of years.
Deuterium (2H or D) is a stable, non-radioactive isotope of hydrogen containing one proton and one neutron. It occurs naturally in water at a concentration of approximately 1 in 6,420 hydrogen atoms (156 ppm). Unlike tritium, deuterium is abundant, cheap, and easy to produce in large quantities through water electrolysis and distillation.[1]
Deuterium is produced industrially by: (1) electrolysis of water (deuterium concentrates in the liquid phase), (2) Girdler-Sulfide (GS) process using H2S/H2O isotope exchange, or (3) distillation of liquid hydrogen. Canada produces heavy water (D2O) for CANDU reactors at ~$300–600/kg. Deuterium gas costs approximately $1,000–3,000/kg — negligible compared to other fusion costs.[2]
Deuterium participates in several fusion fuel cycles: D-T: The easiest fusion reaction (lowest ignition temperature), producing a 14.1 MeV neutron and 3.5 MeV alpha. D-D: Produces either T + p or 3He + n with roughly equal probability; requires higher temperatures but eliminates tritium supply issues. D-3He: Produces a proton and 4He with no primary neutrons; requires much higher temperatures and confinement but enables direct energy conversion.[3]