From the Federation of American Scientists, Special Weapons Primer, Weapons of Mass Destruction (www.fas.org/nuke/intro/nuke/tritium.htm)
“Tritium ( 3 H) is essential to the construction of boosted-fission nuclear weapons. A boosted weapon contains a mixture of deuterium and tritium, the gases being heated and compressed by the detonation of a plutonium or uranium device. The D-T mixture is heated to a temperature and pressure such that thermonuclear fusion occurs. This process releases a flood of 14 MeV neutrons which cause additional fissions in the device, greatly increasing its efficiency.
“Tritium is rare in nature because of its 12.4-year half-life. It is produced by cosmic radiation in the upper atmosphere where it combines with oxygen to form water. It then falls to earth as rain, but the concentration is too low to be useful in a nuclear weapons program. Most tritium is produced by bombarding 6Li [ 6 Li(n, a) 3 H] with neutrons in a reactor; it is also produced as a byproduct of the operation of a heavy-water-moderated reactor when neutrons are captured on the deuterons present.
“Tritium can be stored and shipped as a gas, a metal hydride (e.g., of titanium) or tritide, and trapped in zeolites (hydrated aluminum silicate compounds with uniform size pores in their crystalline structure). Stainless-steel cylinders with capacities up to 5.6 ‘ 10 7 GBq (1.5 MCi) of tritium gas are used for transportation and storage and must be constructed to withstand the additional pressure which will build up as tritium gradually decays to 3 He.
“All five declared nuclear weapon states must have the underlying capability to manufacture and handle tritium, although the United States has shut down its production reactors due to safety considerations. Canada manufactures tritium as a byproduct of the operation of CANDU reactors. (emphasis added) In principle, limited amounts of tritium could be made in any research reactor with the ability to accept a target to be irradiated.
Sources and Methods
- Adapted from - Nuclear Weapons Technology Militarily Critical Technologies List (MCTL) Part II: Weapons of Mass Destruction Technologies”