According to this source [1] flights departing GVA generated 1.3 million tons of CO2 in 2018. According to this source [2], jet fuel generates 3.16 kg CO2 per kg of fuel. Multiplied by approximate fuel density and we get 2.57 kg CO2 per liter. We can therefore estimate that GVA consumes approximately 500 million (1.3 billion kg CO2/ 2.57 kg CO2 per liter) liters of fuel per year. Jet fuel contains about 35 MJ of energy per liter according to [3] so that's about 17.5 PJ. If the process to convert electricity to jet fuel is 50% efficient, that's 35 PJ. That is equivalent to a 1.1GW reactor running at 100% capacity. At the global average capacity factor of 80%, that's about 1.4GW required. Half a dozen is probably a pretty large overestimate. Alternatively, this would require around 6GW of solar, although 6GW of solar is probably quite a bit cheaper than 1.1 GW of nuclear power.