Yeah, this really doesn’t look even remotely surprising to me.

Absolutely everyone involved should already understand that they are not building something that they know how to build.

Sure, they have plans, and they can build to exactly those plans… But even then, there is no guarantee at all that they will then achieve net positive fusion energy. Because nobody has done that in a controlled reaction.

But it’s also not like the rest of the world is sitting still. Other projects exist, and sometimes those projects are going to learn things that will impact the design of ITER.

For that matter, even if they have the plans, some of the pieces are things that nobody has ever built on that scale before, which means that nobody really knows how to build them until they try.

This is a really good example of a project that you can not accurately estimate.