No, the grant, before any reactor, is equivalent to 400 MW (later adjusted down by capacity factor). The nuclear reactor itself is vastly more expensive ($2.4B after the 5th unit). So each reactor is closer to 1500MW of wind (again if we take 30% then 450MW more in line with the reactor) and that’s optimistic (because early nuke estimates tend to underestimate cost). So the real reason for nuclear is that it provides consistent output and thus has lower requirements on the grid.
Or did you leave a number out of your comment and 400MW of wind is only 50M, one-tenth the price.