France to restart tritium production for nuclear arsenal enhancement

French Armed Forces Minister Sébastien Lecornu announced on March 18 that production of tritium, essential for the manufacture of thermonuclear weapons, will be resumed. The production will be carried out using two civilian reactors owned by the EDF conglomerate. We explain why tritium is essential in thermonuclear weapons.

As reported in a press release by the French Ministry of Defence, the production of tritium will not affect the electricity generation by the Civaux nuclear power plant located in southwestern France. Tritium production will take place on the premises of the Commissariat à l'énergie atomique (CEA), a French scientific and industrial facility specializing in nuclear research.

This is the culmination of over 25 years of discussions between the French Ministry of Defence and the EDF conglomerate. The agreement is meant to fill the gap left by the closure in 2009 of two reactors dedicated to tritium production located in Marcoule in southeastern France.

Tritium, a hydrogen isotope consisting of one proton and two neutrons, is very rare in the atmosphere and can practically only be acquired by exposing lithium to the high level of radiation present in a reactor core. Subsequently, tritium can be recovered from the irradiated material, although it is very difficult to store.

Tritium is highly unstable, and its half-life is 12 years, meaning that a constant source of production is necessary. It has many applications, from fluorescent surfaces on watches, keyrings, or firearm sights, to its most important role as fuel in nuclear fusion.

Currently used nuclear weapons are based on thermonuclear warheads, which allow for tremendous destructive power in a very small size. In their case, energy is not produced in a chain reaction of fission of uranium and/or plutonium nuclei but in a thermonuclear fusion reaction, where hydrogen isotopes combine under very high temperature and pressure to form helium, accompanied by the release of a massive amount of energy.

An initial nuclear explosion is required to create the conditions necessary to start the reaction, but its power is a small percentage of the total. The largest thermonuclear bomb ever, Tsar Bomba, had a yield of 50 megatons but was impractical for military use. Normally, much weaker warheads are used, but in larger numbers.

According to estimates, France has 290 warheads, divided into two categories. Strategic weapons include TN 75 warheads with a yield of around 150 kt and tactical TN-81 with an adjustable yield of 150-300 kt. The former are carried by Le Triomphant class submarines launching intercontinental ballistic missiles with a range of 8,000-10,000 kilometres from the M45 or M51 families carrying up to 10 MIRV sub-warheads targeting different objectives.

The latter type is installed in ASMP-A cruise missiles with a range of up to 500 kilometres carried by multirole Rafale aircraft.