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Tritium is a radioactive isotope of hydrogen which has both commercial and military applications. [1] Tritium’s commercial uses include medical diagnostics and sign illumination, especially EXIT signs. However, commercial tritium use accounts for only a small fraction of the tritium used worldwide. [2] Tritium’s primary function is to boost the yield of both fission and thermonuclear weapons. [3] Contained in removable and refillable reservoirs in the warhead, it increases the efficiency with which the nuclear explosive materials are used. Although no official data are publicly available, each warhead is estimated to require an average of approximately four grams of tritium. However, neutron bombs, designed to release more radiation, have been estimated to require more tritium (10-30 grams). [4]

Tritium’s relatively short half-life of 12.3 years and low concentration in nature due to a low natural production rate necessitates artificial production. However, due to safety and health concerns at its aging facilities, the Department of Energy (DOE) has not had an operating tritium production facility since 1988. The DOE estimates that it must have a new facility operating by 2011 in order to maintain the U.S. nuclear arsenal without compromising the five year tritium reserve. [5]

Due to the DOE’s estimate of up to 15 years to plan and construct a new facility, it is currently in the process of deciding upon a new tritium production technology. [6] The final PEIS was released at the end of October 1995 and a Record of Decision was issued in early December. Secretary of Energy Hazel O’Leary decided upon “dual-track” approach. The Department will pursue a “commercial reactor option” while funding accelerator research. Under the “commercial reactor option” the DOE would either purchase a civilian reactor or contract with a civilian reactor operator to purchase irradiation services. The accelerator, if constructed, would be located at the Savannah River Site (SRS) in South Carolina due to its long experience with tritium production and the location of the tritium recycling facility at SRS. The final decision is expected to be made in three years following the assessment of each approach. [7]

The DOE decision leaves open a third option, the new so-called “triple play” reactor. Such a reactor would be fueled by surplus military plutonium and would generate power for civilian consumption. [8] It would pose additional environmental, economic and proliferation risks, according to its opponents. It could still be an option, however, as it still has its proponents in Congress and the nuclear industry.

Determination of the date that the DOE would require a new tritium production facility is driven by the assumed size of the future U.S. weapons stockpile. For a given stockpile composition, a greater number of warheads will require more tritium. However, a decision about tritium production must consider a number of crucial factors, including:

  • the health and environmental effects of tritium production;
  • United States nuclear posture and strategy;
  • non-proliferation policy and adherence to Article VI of the nuclear Non-Proliferation Treaty (NPT).


  1. Tritium (commonly denoted by the letter T) has a nucleus of one proton and two neutrons (ordinary hydrogen has just a single proton and no neutrons). Like all radioactive isotopes, the tritium nucleus is unstable and decays. Tritium decays into helium-3 by emitting beta radiation (electrons). Its half-life is 12.3 years. This half-life means that each year 5.5% of the tritium decays to helium-3. ↩ Return
  2. Commercial tritium demand is 400 grams/year (Kalinowski and Colschen 1995, p. 140). In comparison, the current U.S. arsenal of approximately 10,000 warheads requires approximately 2.2 kilograms/year (at four grams of tritium/warhead) to offset decay. ↩ Return
  3. Thermonuclear weapons (also known as fusion or hydrogen bombs) have a primary and a secondary stage. The primary stage is identical to a regular fission weapon and it is this stage which uses tritium. ↩ Return
  4. Kalinowski and Colschen 1995, p. 142. The Department of Energy classifies numbers concerning the production, inventory, and use of tritium for national security purposes. Analysts use a variety of sources to estimate tritium numbers. The data and estimates used in this paper are drawn from estimates made by the Natural Resources Defense Council, Martin Kalinowski, Lars Colschen and others. ↩ Return
  5. The Programmatic Environmental Impact Statement for Tritium Supply and Recycling (DOE 1995b) lists four possible tritium production technologies: Light Water Reactor, Heavy Water Reactor, Modular High Temperature Gas-Cooled Reactor and Accelerator Production of Tritium. The chosen technology would be either at the Savannah River Site, Idaho National Engineering Laboratory, Nevada Test Site, Pantex Plant, or Oak Ridge Reservation. The National Environmental Policy Act (NEPA) requires the DOE to prepare the Programmatic Environmental Impact Statement (PEIS) before making a decision on tritium production. ↩ Return
  6. The DOE’s estimates are actually less than 15 years, with no delays, for all the technologies. A commercial reactor could be ready by 2005, assuming no institutional barriers. If the DOE were to assume institutional barriers could be overcome in an emergency, it could postpone its tritium production plans by six years. See DOE 1995d Chapter 4 ↩ Return
  7. “Energy Department Favors Dual-Track Strategy to Meet National Security Requirements for Tritium.” DOE Press Release, October 10, 1995 ↩ Return
  8. Surplus military plutonium could only be used if the Storage and Disposition of Weapons-Usable Fissile Materials PEIS results in a decision to use reactors for plutonium disposition ↩ Return