What? Nuclear is cheap to build when the rules hold still. The problem is that while a plant is being under construction (which can be fast), policies change and on a multi-year build, every change means rework and financing costs on capital that is sitting idle. That's the main driver of prices, along with restrictions that keep tightening, the most overbearing being the linear no-threshold model. It's not a problem inherent to nuclear build out. Gas is faster and more modular because it is less encumbered and because we have far more experience building it. If gas/carbon construction was as hampered as nuclear is, the costs would be equivalent. They are not, because coal and gas have the backing of powerful interests that would not let that kind of policy instability happen. Meanwhile, nuclear has no backer with the same amount of resources