That's an excellent point! Perhaps they intend the truck to be sitting at the bottom of a fast moving river.
But what gets me is that they are burying the lead. No fusion reactor of any size has reached sustainability...so why is the story here talking about size at all? Small size would be a very nice added bonus; fusion reactors that don't consume more energy than they produce are earth-changing.
What the commenter is pointing out is that it may not matter how you cool the reactor. It could be in interstellar space and it might not matter because the material the reactor itself is made of may not be able to transmit the heat away from the reactor. And no such material may exist.
I agree that the announcement is a bit burying the lead here, though maybe the size is actually important to making it work. From Aviation Week[0]:
"But on the physics side, it still has to work, and one of the reasons we think our physics will work is that we’ve been able to make an inherently stable configuration.” One of the main reasons for this stability is the positioning of the superconductor coils and shape of the magnetic field lines. “In our case, it is always in balance. So if you have less pressure, the plasma will be smaller and will always sit in this magnetic well,” he notes."
As far as I understand this (IANAP), they're saying that smaller size = less pressure, and that helps their design to work (in theory).
I think it is more a matter of tolerances than of size what makes ITER take so long. Also, it is experimental. That means that it is not just a matter of ordering stuff and putting it together.
But what gets me is that they are burying the lead. No fusion reactor of any size has reached sustainability...so why is the story here talking about size at all? Small size would be a very nice added bonus; fusion reactors that don't consume more energy than they produce are earth-changing.