Not really. One of the things prohibiting the market is the Price-Anderson Act, which stipulates, irrespective of the sort of reactor (and since there have been newer and cheaper reactor designs) a level of insurrance that nuclear plants need. Effectively, this has made it impossible to enter the market with reactor designs that are smaller and safer and do not require the insurance proscribed by the act. I don’t personally know operational costs for these other sorts of reactors, but suffice it to say there are artificial limitations in place that skew this market.

It doesn't skew the market, it just prevents externalizing of costs.

How does it not (potentially) skew the market? If one such alternative plant had a higher operating efficiency and therefore lower cost, wouldn't the fact that there is a law preventing the lower cost from being reached skew the market? Am I missing something?

Not quite: the main thing hurting nuclear isn't wind/solar, it's natural gas. Which is unfairly cheap (and thus effectively subsidized) because the externality costs of CO2 aren't being priced in. If we had a carbon tax and thus a level playing field, nuclear could beat natural gas.

I disagree with this thesis. Renewables are killing nuclear because renewables have no marginal fuel cost. Natural gas can always spin down dictated by grid demand, nuclear must always maintain a certain level of output; If its generation is crowded out by renewables, it must sell electricity at a loss.

Nuclear could survive even without a carbon tax on natural gas if you could find large power consumers who would sign direct PPA agreements with commercial nuclear generators (as power consumers have done with wind and solar plants), perhaps utility scale battery operators.