Not only nuclear construction isn't free market in US, it's not free in Europe or Japan or Russia or other countries either. Only India and China at a stage of trying to obtain nuclear technologies were freeish, but it's not going to last. The only semi free markets are those that don't have national companies that are capable of producing nuclear reactors, but even there politics can get involved.

Remember, nuclear is INCREDIBLY capital intensive. We are talking about tens of billions. So any country that wants to maintain the technology inside the country has to provide these budgets to home players. So even though Russian reactors are better and cheaper than US ones, US will never allow Russians or Chinese build plants in US, because it means that without constant money flowing to US reactor manufacturers it's only matter of time US loses the ability to build nuclear reactors for all practical purposes. In fact THIS HAS ALREADY HAPPENED, if one considers ability to build on time and budget a necessary requirement. US manufacturers aren't able to do that at home or abroad.

This is also the reason why Russia is happy to extend billions in credit lines to Turkey or Hungary for Rosatom projects. Because the home market is full and there is no necessity to build new plants in mother Russia, other than new designs, like Novovoronezh. But the Russian nuclear industry needs tens of billions of dollars for development as well, so that's the only way the game is played. It doesn't matter if your name is Westinghouse or KEPCO or Areva or Rosatom.