tritium
noun
tri·ti·um ˈtri-tē-əm 
ˈtri-shē-
: a radioactive isotope of hydrogen that has one proton and two neutrons in its nucleus and that has three times the mass of ordinary hydrogen —symbol T
Example Sentences
Recent Examples on the Web The National Nuclear Security Administration is scaling up tritium output at Watts Bar and other civilian nuclear plants, but such production was delayed this year by the steam generator replacement project at Watts Bar. 
Tribune News Service, al, 6 Aug. 2022 In addition to its power generation, TVA helps the U.S. military irradiate tritium-producing burnable absorber rods at Watts Bar. Tribune News Service, al, 6 Aug. 2022 Priest said that Potvin’s claim about the amount of tritium, a radioactive isotope, in the water was exaggerated by 10,000 times. Mike Damiano, BostonGlobe.com, 26 July 2022 Deuterium has one proton and one neutron while tritium has one proton and two neutrons. David Donovan, The Conversation, 4 Apr. 2022 Better methods must also be developed for on-site production and handling of tritium to use as fuel. Philip Ball, Scientific American, 2 Feb. 2022 The 50 million watts is only the power supplied directly to the deuterium and tritium fuel. Don Lincoln, CNN, 11 Feb. 2022 Set up to reflect the design of ITER, and with the mix of deuterium and tritium fuel that will be used there, JET made the largest sustained fusion reaction yet. John Timmer, Ars Technica, 9 Feb. 2022 That lets the pilot project avoid having to source rare, radioactive tritium and deal with the excess heat and generated radioactivity. Daniel Clery, Science | AAAS, 16 June 2021 See More
Tribune News Service, al, 6 Aug. 2022 In addition to its power generation, TVA helps the U.S. military irradiate tritium-producing burnable absorber rods at Watts Bar. Tribune News Service, al, 6 Aug. 2022 Priest said that Potvin’s claim about the amount of tritium, a radioactive isotope, in the water was exaggerated by 10,000 times. Mike Damiano, BostonGlobe.com, 26 July 2022 Deuterium has one proton and one neutron while tritium has one proton and two neutrons. David Donovan, The Conversation, 4 Apr. 2022 Better methods must also be developed for on-site production and handling of tritium to use as fuel. Philip Ball, Scientific American, 2 Feb. 2022 The 50 million watts is only the power supplied directly to the deuterium and tritium fuel. Don Lincoln, CNN, 11 Feb. 2022 Set up to reflect the design of ITER, and with the mix of deuterium and tritium fuel that will be used there, JET made the largest sustained fusion reaction yet. John Timmer, Ars Technica, 9 Feb. 2022 That lets the pilot project avoid having to source rare, radioactive tritium and deal with the excess heat and generated radioactivity. Daniel Clery, Science | AAAS, 16 June 2021 See More Word History
Etymology
New Latin, from Greek tritos third — more at third entry 1
First Known Use
1933, in the meaning defined above
Medical Definition
tritium
noun
tri·ti·um ˈtrit-ē-əm ˈtrish-ē-
ˈtrish-ē- : a radioactive isotope of hydrogen that has three times the mass of ordinary hydrogen —symbol T