For context, 5GW is massive amount of electricity. Two of largest european NPPs have 5.7GW (Zaporozhian NPP, pre-2022) and 5.6GW (Gravelines NPP), and that's nameplate capacity, some part is always down for maintenance/refueling. That's quite a significant part of these respective countries electricity generation (over 20% for Ukraine and almost 6% for France). If you want to have 5GW available at all times, then something closer to 8-10GW nameplate capacity would be in order. That's larger that biggest current nuclear installations in the world (7GW-ish Chinese and Korean NPPs)