My father and I went on an equally in-depth guided tour of Hinkley Point station back in the mid '80s when I was a boy. We too got to walk on the reactor lid, view the cooling ponds, and meander underneath miles of thrumming piping. It was utterly fascinating and one of the very best memories I have of my childhood. Hinkley Point is a PWR rather than an AGR, but what the author writes about that collision of space age technology and Victorian plumbing definitely rings true.
Other highlights for me not mentioned in this article: a great video showing a high speed diesel train (not just the locomotive) crashing into a waste transport container; climbing around a whole fleet of tiny decontamination trucks with radiological protection gear for the drivers and manipulator arms for picking up material; and getting hands-on with the security system (not part of the tour; my dad made a friend) and broadcasting over the plant tannoy. No chance of any of that stuff happening for my kids, sadly.
I was happy to read this even if it is a repeat. A great write up that took me back.