One of the reasons why the timeline is so long is that a reactor will have to be connected to a system that can exchange the tritium (and deuterium). Now, sinc

One of the reasons why the timeline is so long is that a reactor will have to be connected to a system that can exchange the tritium (and deuterium). Now, since both are hydrogen isotopes they can diffuse like crazy. Leaks of tritium are bad because it is radioactive (alpha radiation, which is not so bad unless incorporated, but it's a gas, so yeah). Also, some processing like isotope sorting will have to be in the circle. Right now, all these new technologies are being developed, which takes a lot of work, money, time and PhD students.