$0.5B is a tiny rounding error in the cost of standing up the first GW of a new tech. If SMRs could be built for $10/W, which is overly optimistic, that would be $10B. Much more likely is $30B-$50B for that first GW. And SMRs are not even going to start getting to a halfway competitive cost until at least several GW in. If they can eventually get to $5/W they might have a chance at competing for a fraction of the grid.

All this is to say that if there are high costs imposed by regulation, it's not the regulatory process it's in the cost of building the final design.

However, the "regulations make nuclear expensive" folks never seem to be able to propose the changes that might make nuclear cheaper, or by how much. The only concrete proposals I have heard are from people skeptical that nuclear can ever be cost competitive!