Of course there is, it's happened exactly the way I said in South Korea, Japan, and American naval reactors. These projects take a long time to complete and there have been relatively few of them. It therefore stands to reason that the cycle of learning from them and making their construction more predictable would take longer than for e.g. cars.
Far too many people are generalizing from the French and American nuclear programs, both of which built lots of reactors in a comparatively short time and then were fear-mongered into a standstill by the fossil fuel lobby.
"""In the third era of nuclear power construction in Japan, from 1980 to 2007, costs remain between ¥250,000/kW and ¥400,000/kW, representing an annual change of −1% to 1%. This period experienced relatively stable costs over 27 years."""
Far too many people are generalizing from the French and American nuclear programs, both of which built lots of reactors in a comparatively short time and then were fear-mongered into a standstill by the fossil fuel lobby.
https://www.sciencedirect.com/science/article/pii/S030142151...
"""In the third era of nuclear power construction in Japan, from 1980 to 2007, costs remain between ¥250,000/kW and ¥400,000/kW, representing an annual change of −1% to 1%. This period experienced relatively stable costs over 27 years."""