I did some scientific computing for OL3 in 2009-10 and the issue you're referring to is a different one. Back in the 80's, there was around 5 new nuclear plants built in France, each year. It powers 75% of our electric grid and most of these plants are still going to be here till 2020-2040. Now most people who conceived and designed those plants are retired or almost retired. The new EPR plants (OL3, FA3) suffered consequently, the project management and the engineering is pretty much fucked up (personal point of view, I didn't had much insight). Also Areva consciously sold the plant for a low price in order to win the auction, they knew from day 1 that it would be delayed but probably not that much.

Now I was referring to the inherent difficulty to scale fusion up due to the underlying physics. So when the article says:

> The next steps for the dynomak are straightforward. The experimental device [...] is about one-tenth the size that a commercial dynomak fusion reactor would be. [...] the group hopes to construct HIT-SIX [...] that will be twice as large as HIT-SI3. >At that size, things start to get interesting, says Sutherland. If imposed-dynamo current drive works well in HIT-SIX, he’ll be “much more confident going forward that our development path will be successful,” he says.

I don't know if it will be that straightforward because they're building a 1/10 prototype to build a 1/5 proto and then if all goes well they could be more confident about building a full scale plant. Does someone know how scaling up 1/10 → 1/5 → 1/1 is or isn't such a big issue ?

You forgot Flamanville 3 in France: http://en.wikipedia.org/wiki/EPR_(nuclear_reactor)#Flamanvil.... Same problems though (huge delay, budget increase, ...)

And Hinkley C in Somerset, UK http://www.theguardian.com/business/2014/nov/20/hinkley-poin... (again, delays etc - currently only earthworks are going on)

Also not an expert. My impression was that the high cost of fission plants can be attributed to safety features that aren't required with fusion. (And arguably aren't required -- to the extent society demands them -- with fission plants either.)