>> I do know enough about math and engineering to know that the only realistic way to deal with the disaster they are predicting is an immediate and massive expansion of nuclear power

Would it not be cheaper, whilst also being realistic, to pursue renewables + natural gas?

AIUI renewables LCOE is around 5x cheaper than nuclear and natural gas is often (including right now) sold at negative prices in the US because it is almost a waste product from far more lucrative shale oil operations (accounts for around 80% of gas production). Add to this gas is a near perfect complement to renewables given its fast response times to demand changes unlike nuclear. Natural Gas is also the cleanest of the fossil fuels, modern generation facilities are far more efficient than e.g. petrol or diesel engines.

I’m failing to understand why nuclear would be the only game in town? Those construction costs make it look unviable. Not to mention the NIMBY aspect which means nuclear is simply off the table in terms of options thanks to citizen desires.