It's a sad case of "too little too late".
The best time to build up nuclear power was 4 decades ago - when the supply of fossil fuel was obviously fraught, and things like solar and wind power were nonviable.
Whether it makes any sense to push for nuclear power now is unclear. Nuclear was quite expensive even back then - but decades of NIMBYism, "environmental" activism and overregulation have damaged the industrial capability and eroded supply chains to the point that getting a buildout going at scale, on a sane budget and a sensible timetable would be an uphill battle. At the same time, renewables aren't anywhere near as opposed, the economic outlook for solar, wind and grid storage is better than it ever was, and the situation is likely to improve even further.
I'm not so sure I agree. A big turning point in my thinking was reading a mid 1980s Forbes piece that investigated several other factors that stopped more US nuclear builds. Perhaps most of all was lack of need, there were too many starts resulting in a glut of nuclear power. Second, construction projects were frequently over budget, meaning the power wasn't as cheap as everybody anticipated. Third, yes, there were mid-construction design changes but that was only on a fraction of projects that were already way behind.
Look over at France, frequently touted as a "successful" buildout. But reactors got more expensive the more they built, not cheaper, and they never met their initial goals for number of builds.
And look at the one place with modern-day "successful" builds: China. They like to tout the reactors as great successes, and they are on time and on budget, or at least as on budget as we can tell in an economic system like that. But they missed their 2020 and 2025 five year plan goals for deployment, and will miss their 2030 goal too. Meanwhile, they deploy 20x-30x as much wind and solar each year, each tech. That's after adjusting for capacity factor! So the best nuclear builders in the world are only building enough of it to be low single digits of their energy mix.
Nuclear was always oversold as a technology, always underdelivered, and has not seen a positive learning curve that a normal technology would. It was doomed from the start, IMHO.
But 4 decades ago is exactly when nuclear was being built up in the UK - indeed, most of the AGR fleet came online between 1985 and 1989.
And "quite expensive" vastly understates it - high temperature gas-cooled reactors are in theory more efficient in operation at the expense of increased construction cost. In reality, construction costs far, far outweigh the raw cost of fuel (reprocessing is a different matter!) so we landed ourselves with all the extra expense for very little benefit (probably actually a negative benefit since the much-vaunted ability to refuel whilst at full power turned out not to work in practice).
So they were late, hideously expensive, completely failed to be sold to other countries, and now have an availability factor no higher than that of offshore wind.
We knew that they would be unlikely to live up to their promise as early as 1964 and yet still went ahead despite several opportunities to change course. The nuclear industry never learns.
The background here is that people didn't really trust the individuals or institutions involved with nuclear power, and those same individuals and institutions weren't exactly enthusiastic about a new form of energy.