The fully-baked lifetime costs of nuclear power are quite vigorously debated; it's hard to get accurate numbers, since in general there are unpriced government insurance policies backing the plants (i.e. the government will step in to pay the $10B cleanup costs in the unlikely event that something goes wrong).
One way of attempting to answer this question is to look at France, where 75% of their power is nuclear; their price per KWh for consumers up to 2015 was lower than the average for Europe (12th-cheapest in Europe according to Wikipedia, and 2nd-lowest for commercial), but that almost certainly doesn't price the government insurance mentioned above [2].
Note that due to a lot of electric heating in residential stock, France is very susceptible to increased demand in cold winters; in such situations they have to import from the rest of Europe, sometimes at peak hours. And as of 2016, a bunch of French reactors were shut down over safety concerns, so the prices there are spiking dramatically [3].
Another approach; let's look at cost per installed MW of power for current projects. For solar, that's now beating wind (and half the price of coal) for the newest installs, at $1.65M/MW [4]. According to the World Nuclear Association (who I'm going to assume will give the best possible numbers that can be said with a straight face), nuclear installs are ranging from ~$2.5M/MW to $7M/MW of capacity, with most cases closer to the high end of that range [5].
Now, load factor appears to be around 20% for US desert installs [6], so you need 4.5x more installed capacity to meet nuclear's load factor of 90%. Load-factor-adjusted costs: solar $8.25M/MW, nuclear $2.8M/MW - $7.8M/MW. That makes it look a lot closer than your numbers suggest. A deeper analysis would include pricing energy storage (which increases the cost of solar more than nuclear, but does need to be considered for an all-nuclear mix) and subsidies (which predominantly increases the cost of nuclear).
I haven't done more than skim your link, which seems interesting reading, and I'll dig into that later. But the from-first-principles analysis doesn't seem to be using the right costs for solar; it has `Cost: $12.3 Billion` for a 500MW CSP installation, or $24.6M/MW. That's a factor of 15 above the observed cost of installing a modern solar plant. It might be accurate for a CSP plant, but that's not the cheapest solar available.
In summary, I'm somewhat agnostic on this issue, but the energy storage issues with solar/wind seem like they could push the cost up substantially as we start to get towards majority-renewable on our grid, so I tentatively support building some new nuclear as a short-to-medium-term hedge. But we should be sure to do so with as little subsidies as possible, so that the installation price reflects the true cost, rather than kicking the can down the road on billions of dollars of decommissioning costs. And entirely new reactor designs (e.g. fast breeders) could change the calculus entirely.
Caveat emptor; I'm not in the energy business, so there's probably some missing steps here. Please let me know if you spot one.
My thinking is pretty similar to yours. Especially the point on subsidies, although I would modify it slightly: if subsidies are employed (explicitly, or implicitly in the case of 'nuclear insurance'), governments should aim to keep them as technologically neutral as possible. I'm not arguing against subsidies (especially at this point): if it's a choice between climate catastrophe or handing out subsidies I'd definitely go with the subsidies. However, I think it's counter-productive (and more costly in the long-run) for governments to distort alternative energy markets by 'picking winners' (as they always seem to do). In other words, subsidise equally.
Carbon pricing always seemed like the elegant, 'neutral' solution to me, but it doesn't seem very popular. Also people seem to have trouble understanding that it makes perfect sense to cycle the revenue back to individuals (e.g. tax cuts), as the point is to make co2 emission intensive activity relatively more expensive (meaning people efficiently substitute away).
On the solar costs, it sounds like you've made a fair calculation (although I'm by no means an expert either, so not really qualified to make any kind of judgement). Although one other factor (which you might have already built in to your unit price) is the cost of transmission infrastructure: renewables (particularly wind) need to be geographically distributed to ameliorate their intermittancy issues (i.e. the wind only blows in some parts or the country at any given time, the sun is only visible from some perspectives etc.). Either that or, as you pointed out, you need quite a lot of energy storage capacity. Most likely there's some optimal mixture of both.
And I should probably correct something that I think I (mistakenly) said earlier as well: nuke plants, although they can scale up and down to try and match demand, it apparently is not a fast process (meaning at least some energy storage or 'peaking'/'energy sinking' capacity is required, somewhat mitigated by good predictive models of demand).
One way of attempting to answer this question is to look at France, where 75% of their power is nuclear; their price per KWh for consumers up to 2015 was lower than the average for Europe (12th-cheapest in Europe according to Wikipedia, and 2nd-lowest for commercial), but that almost certainly doesn't price the government insurance mentioned above [2].
Note that due to a lot of electric heating in residential stock, France is very susceptible to increased demand in cold winters; in such situations they have to import from the rest of Europe, sometimes at peak hours. And as of 2016, a bunch of French reactors were shut down over safety concerns, so the prices there are spiking dramatically [3].
Another approach; let's look at cost per installed MW of power for current projects. For solar, that's now beating wind (and half the price of coal) for the newest installs, at $1.65M/MW [4]. According to the World Nuclear Association (who I'm going to assume will give the best possible numbers that can be said with a straight face), nuclear installs are ranging from ~$2.5M/MW to $7M/MW of capacity, with most cases closer to the high end of that range [5].
Now, load factor appears to be around 20% for US desert installs [6], so you need 4.5x more installed capacity to meet nuclear's load factor of 90%. Load-factor-adjusted costs: solar $8.25M/MW, nuclear $2.8M/MW - $7.8M/MW. That makes it look a lot closer than your numbers suggest. A deeper analysis would include pricing energy storage (which increases the cost of solar more than nuclear, but does need to be considered for an all-nuclear mix) and subsidies (which predominantly increases the cost of nuclear).
I haven't done more than skim your link, which seems interesting reading, and I'll dig into that later. But the from-first-principles analysis doesn't seem to be using the right costs for solar; it has `Cost: $12.3 Billion` for a 500MW CSP installation, or $24.6M/MW. That's a factor of 15 above the observed cost of installing a modern solar plant. It might be accurate for a CSP plant, but that's not the cheapest solar available.
In summary, I'm somewhat agnostic on this issue, but the energy storage issues with solar/wind seem like they could push the cost up substantially as we start to get towards majority-renewable on our grid, so I tentatively support building some new nuclear as a short-to-medium-term hedge. But we should be sure to do so with as little subsidies as possible, so that the installation price reflects the true cost, rather than kicking the can down the road on billions of dollars of decommissioning costs. And entirely new reactor designs (e.g. fast breeders) could change the calculus entirely.
Caveat emptor; I'm not in the energy business, so there's probably some missing steps here. Please let me know if you spot one.
[1]: https://www.bloomberg.com/news/articles/2016-12-15/world-ene... [2]: https://en.wikipedia.org/wiki/Nuclear_power_in_France#Manage... [3]: http://www.zerohedge.com/news/2016-10-27/french-shocked-powe... [4]: https://www.bloomberg.com/news/articles/2016-12-15/world-ene... [5]: http://www.world-nuclear.org/information-library/economic-as... [6]: http://euanmearns.com/estimating-global-solar-pv-load-factor...