Not sure about this
"The usual means of doing this is to confine a superhot plasma of appropriate light nuclei under massive heat and pressure inside a doughnut-shaped vessel using magnetic fields to suspend the plasma and prevent it destroying the structure. Sadly, so far these doughnut "tokamaks" have always required more power to run than they can generate."
I sat through a seminar while I was doing my postgraduate degree at uni, we had a guy from JET coming down and talking to us for 3 hours. The question of the hot plasma destroying the reactor came up.
The fact of the matter is that the thermal mass of the plasma is low despite it being very hot. The actual problem is that if the plasma touches the walls of the reaction vessel it will cool down and the reaction will stop. A single proton hot proton touching a lump of metal will not heat the metal up very much, the proton will just cool down.
Also the reason for building a bigger reactor is that it is easier to contain the plasma in a larger space.
I second point is they tend not to use tritium right now because they want to go inside the reactor vessel to inspect it after the experiments. High energy neutrons can be captured by the walls of the reaction vessel and create radioactive isotopes making it dangerous to then go inside and inspect it. They tend to only use deutrium which doesnt release as much energy.
I do remember they said that the amount of lithium in a laptop battery would power the UK for a year or something ridiculous like that. It was impressive....the commercial timelime they layed out in this seminar was 2030 - 2050 for power being generated by these reactions powering the national grid. We are still a long way off!