First, are we talking inflation adjusted dollars? Second, a large part of the problem is the continued ever since the 70s anti-nuclear power hysteria. This has greatly inflated costs, danger estimates, required procedures and so on. It is also why we have no spend fuel repository although we no several ways to create a quite good one. And it is also why all forms of breeder reactors, even those not good for making weapon grade materials, were killed. That move means there is around 20x more "nuclear waste" than there would otherwise be as 95% of it would have been used in a breeder. Lastly it is why we can't build any more modern designs that are much safer and more efficient. Even though nuclear with the antiquated designs has a three orders of magnitude better safety record in terms of number of deaths per TwH generated than coal and two orders of magnitude better than oil and gas.
So don't let this railroad you to the wrong conclusion.