A radioactive isotope of hydrogen whose nucleus contains one proton and two neutrons. The symbols for tritium are T and 3H; the latter symbol is more frequently encountered. If appropriate to the context add: Used in thermonuclear weapons
National Environmental Policy Act (NEPA), Glossary of Terms Used in DOE NEPA Documents, US Department of Energy, Office of NEPA Policy and Compliance, USA 1998. http://energy.gov/sites/prod/files/NEPA_Glossary%2 008_2011.pdf, (EHS - Amer) {515}