I spent a fun 6 months there as a placement when I did physics. Great place and some of the brightest people I have ever worked with.
I was in the UK part, which had a definite heath robinson feel to it compared to the JET area. However the advantage was that we could try out and reconfigure ideas far easier. Basically the UK was a old ford . that you could take apart and re-purpose while JET was a rolls-royce, that was the ultimate in technology, but expensive to customise.
One situation that comes to mind was the mess when one of the capacitor banks that provided the high voltage exploded spraying the room with large amounts of castor oil, which was the electrolyte used
One thing that is not mentioned is the basic research had a huge number of spin-offs including magnets, cryogenics, power electronics, material physics. A lot of people who worked at Culham have gone off to create new products based on that science. Even if economic fusion is never achieved, the path followed has more than enough benefits to justify us following it.
The UK has benefited greatly from such EU projects. The scale means they are beyond the resources of even the richest national governments so require collaboration. That collaboration brings the other benefits of creating a fantastic melting pot of ideas and cultures. It would be a pity, nah, disaster if we flush that down the toilet of political short-termism and myopia.
In the end working at Culham made me realise that I was not cut out for high level physics, but it did give me an opportunity to play with multiple PDP-11(it was that era), and pushed me into software