It doesn't seem like we have much of a choice on the matter. Wind and Solar are even harder to balance, and without dramatic over investment, are unlikely to make up more then 10-15% of our energy needs each. Not only that, but for wind, we would have to build over 1.2 TWh of maximum capacity just to get our 40% base load on average. How much would it cost to produce that many wind turbines? I bet is significantly higher then your $600 billion to $1 trillion figure. Not only that, but the infrastructure would have to be completely retooled to allow those setups. You would have to construct massive storage facilities. With the N/H setup, you would only need some large tanks on site that are then used in hydrogen gas power plants. I bet you would end up SAVING a lot of money this way, most likely far more then the cost of all those nuclear power plants themselves.

And as you said, the obvious way to make such a scheme plausible and economical to do is to have a carbon tax. At which point, its way more profitable to simply create hydrogen via electrolysis's then it is to burn coal plants on standby as it a current common practice. I think you are underestimating the nuclear industry. This year, we are going to have dozens of new plant applications, especially on the west coast thanks to California's recent law that requires out of state electricity to come from clean sources.

Lastly, the problem with nuclear waste storage is grossly over-exaggerated. Many environmental and coal lobbying groups have made a far larger issue out of nuclear waste storage then it actually is. Over the lifetime of a nuclear plant, 97% of the uranium used can be reprocessed for use in other plants. Effectively, we're talking about a few tons of 'waste' from each nuclear plant over the course of 30-40 years. I'm sure you have probably noticed that France does not seem to have any kind of problem with their nuclear waste management.