No, we don't need nuclear. Intermittency of renewables is a problem that has solutions, and the cost of those solutions is low enough to render new construction nuclear entirely uncompetitive in the US and Europe, and likely elsewhere. At worst, if the cost estimates of the solutions are grossly underestimated, this just means we're paying a bit more. At the same time, costs of nuclear power plants are consistently grossly underestimated, so one should honestly address the cost risk on both sides.