Good point Bonds...never thought of it that way as far as security goes. TSA is paid for by the federal government roughly 2/3rds and 1/3rd by a fee on each ticket from what I could find. You could say that some of the utilities are quasi government agencies since some are paid for by regulated utility bills....kind of like a tax, which is where the $$$ come from for the TSA just federally instead of a state tax. But then each airline doesn't have to contend with an extra fee to stay in business (security) like a company that owns nuclear plants has to, since security costs would be a part of that company's bottom line in nuclear.
But the question of whether it is economical to run a nuclear plant versus a gas plant SHOULD still include the nuclear plant's security budget, shouldn't it? I am a big fan of nuclear power, but I won't overlook the obvious just to make my case. Airports are special in one way because they are the only feasible way to get from A to B in many cases....there is no alternative if you want to get to London today, or across the United States quickly, and they have special security needs different from every mode of travel. A nuclear plant produces power, but so does a gas plant. There is no other option for the special travel features that an airport provides.
I don't think nuclear plants should have near as much security as they do and I think they are critical for the united states to have a diverse source of electricity. That doesn't mean we should pretend their real cost to produce power is lower because they have different security needs from other types of power plants. Nuclear plants need more security and that costs more WHOEVER is paying for it (public or taxes).
The real question is do we value a nuclear plant's production regardless of cost (as long as it is in the ball park, which it is). I think the answer is a strong yes.