Nuclear power plants have a huge lead time and require government approval, something the Finnish government declined to approve (Fortum had requested to build a third reactor). Solar and wind are fine but they’re not usable as a replacement for nuclear without huge battery installations which make the cost worse than nuclear. Also large installations still take time - from regulatory approvals to actually building the thing to connecting it to the grid. To give you a sense of scale, of the 53GW of planned wind projects, only 0.9GW are under active construction.

Also, unlike solar and wind, nuclear is a very important anchor source to prevent fossil fuel use in the grid. Solar and wind only absorb growth but so far have never managed to actually compete on baseload power requirements.