Editing Tritium (section)

==== USA ====
Tritium for American [[nuclear weapon]]s was produced in special [[heavy water reactor]]s at the [[Savannah River Site]] until their closures in 1988. With the [[START I|Strategic Arms Reduction Treaty]] (START) after the end of the [[Cold War]], the existing supplies were sufficient for the new, smaller number of nuclear weapons for some time.

{{convert|225|kg|abbr=on}} of tritium was produced in the United States from 1955 to 1996.{{efn|Total U.S. tritium production since 1955 has been about 225&nbsp;kilograms, an estimated 150&nbsp;kilograms of which have decayed into helium-3, leaving a current inventory of about 75&nbsp;kg of tritium. — Zerriffi & Scoville (1996)<ref name="IEER Production">
{{cite web
 |last1=Zerriffi |first1=Hisham
 |last2=Scoville |first2=Herbert Jr.
 |date=January 1996
 |title=Tritium: The environmental, health, budgetary, and strategic effects of the Department of Energy's decision to produce tritium
 |page=5  |language=en
 |publisher=[[Institute for Energy and Environmental Research]]
 |url=http://www.ieer.org/wp/wp-content/uploads/downloads/2012/05/Tritium_1996_Zerriffi.pdf
 |access-date=6 September 2018
 |archive-url=https://web.archive.org/web/20141016031739/http://www.ieer.org/wp/wp-content/uploads/downloads/2012/05/Tritium_1996_Zerriffi.pdf
 |archive-date=16 October 2014
}}
</ref>}} Since it continually decays into helium-3, the total amount remaining was about {{convert|75|kg|abbr=on}} at the time of the report,<ref name="IEER Production" /><ref name=ieer/>
and about {{convert|16|kg|abbr=on}} as of 2023.<ref>27 years have passed since 1996, i.e. 2.25 half-lives, which reduce the 75kg of 1996 to 75/2^(2.25) ≈15.8 kg.</ref>

Tritium production was resumed with [[irradiation]] of rods containing [[lithium]] (replacing the usual [[control rod]]s containing [[boron]], [[cadmium]], or [[hafnium]]), at the reactors of the commercial [[Watts Bar Nuclear Plant]] from 2003 to 2005 followed by extraction of tritium from the rods at the Tritium Extraction Facility at the [[Savannah River Site]] beginning in November 2006.<ref>
{{cite web
 | title=Defense Programs
 | department = [[Savannah River Site]]
 | publisher = U.S. Department of Energy
 | url=http://www.srs.gov/general/programs/dp/index.htm
 | access-date=20 March 2013
}}
</ref><ref>
{{cite web
 | title = Tritium Extraction Facility
 | series = Factsheets
 | date = December 2007
 | department = [[Savannah River Site]]
 | publisher = U.S. Department of Energy
 | url = http://www.srs.gov/general/news/factsheets/tef.pdf
 | access-date = 19 September 2010
}}
</ref> Tritium leakage from the rods during reactor operations limits the number that can be used in any reactor without exceeding the maximum allowed tritium levels in the coolant.<ref>
{{cite press release
 |last=Horner |first=Daniel
 |date=November 2010
 |title=GAO finds problems in tritium production
 |website=Arms Control Today
 |url=http://www.armscontrol.org/act/2010_11/GAOTritium 
}}
</ref>