In Finland's case, the realistic alternatives are burning coal or burning Russian gas. (If the Finns dedicated a substantial chunk of their forests to this one generator, they could maybe use biomass.)
Coal kills two orders of magnitude more people per GWh than nuclear--and it does that when operating nominally, not when malfunctioning--and it produces three or four orders of magnitude more waste and more environmental harm from mining.
Russian gas has geopolitical/national security problems.
Biomass is a roundabout way of burning diesel fuel and gas, while degrading and eroding forest soils and polluting watersheds.
The number of new meltdowns per decade rounds to zero, to five significant figures.
That's a weird metric (one meltdown is quite a catastrophe) and the calculation seems suspicious too. Between Chernobile and Fukushima I don't see how this could be correct.
I do find your other points more convincing, though with some "citation needed" wrt. coal.
And that's before we consider the environmental and health risks of ash ponds[2], which can (and have caused) heavy metal pollution in nearby groundwater supply. The largest industrial spill in US history happened barely a decade ago, and was an ash pond[3].
Edit: I can personally recommend "The Buffalo Creek Disaster" (ISBN 9780394723433) as a writeup by a lawyer involved in a similar coal ash accident (one that directly killed over 100 people).
[1]: https://www.pnas.org/doi/10.1073/pnas.2017936118
[2]: https://en.wikipedia.org/wiki/Ash_pond
[3]: https://en.wikipedia.org/wiki/Kingston_Fossil_Plant_coal_fly...
Just as you wouldn't factor Amelia Earhart's plane into 2022 air safety prognoses, you shouldn't use Chernobyl reactors for nuclear safety.
Nuclear fision reactors safety technology have moved further. There are challenges, but we havent even tried to solve them fully (as we were busy improving gas burning efficiency)
TMI and Fukushima were both "modern" when built. All reactors that melted down did because operators ignored construction, maintenance, or operating safety standards. Other plants not yet melted down show evidence of more construction standard failings: pumps installed despite failing to meet specifications, bolts of substituted, inadequate steel. Diablo Canyon is built directly on a fault line. Now we learn that new EPR plants are inherently flawed, by design.
Ignoring standards is, by the evidence, itself standard procedure for building and operating civil nuke plants. Our global society, as it is conducted, is by the evidence unable to produce and operate a safe civil nuke.
The RBMK reactor is quite an elegant design. Simple plug-and-play architecture for adding and removing fuel and other assemblies while the reactor was running, perfect for things like doping silicon for semiconductors and producing plutonium for weapons. But to get this capability you have to either give up affordability or safety, and they chose to give up safety.
Energy generation is always a trade off. Right now the world is reacting to the fossil fuel funded wars created by one such trade off. We are also in the middle of causing irreversible climate change, which would cause more damage than any amount of meltdowns or nuclear waste could ever get near.
Naturally there are alternatives. If money were no objection then green hydrogen looks pretty nice, and one could always extract heat from the core of the earth as long the technology was safe enough to do so. As soon we have a technology that get proven to be cheaper, safer and more scalable than nuclear we should all switch to that. Buying natural gas from Russia is for multiple obvious reason not that.
Less radioactive EMISSION during NORMAL OPERATION than coal plants (and I think that ignores radioactivity released in uranium mining). The amount of radioactivity in the spent fuel rods of a nuclear plant is vastly higher than that liberated by a coal plant.
BTW, your chance of dying from cancer in your lifetime is about 20%, so I'm not sure that the 1/5 figure you gave there means anything.
There is a place in the US that has a rather peculiar name of Cancer Alley. It is not a nuclear testing area, nuclear waste deposit area or area for nuclear plants. It is an area know for its petrochemical plants. It illustrate quite well the difference of nuclear waste that people are scared of, and fossil fuel waste that people accept as just normal part of life.
Maybe the problem is the uranium mine tailings are safely off in some poor country, not in the US where the coal ash would be?
https://en.wikipedia.org/wiki/List_of_countries_by_uranium_p...
Moreover the more we obtain uranium (prospecting, mining, milling...), the more we add to the associated carbon footprint. Therefore a sustained growth of installed nuclear capacity will lead us to exploit mines at always lowering ore grades => more emissions.
Scientific studies are clear: M. Lenzen ("between 10 and 130 g CO2-e/kWhel, with an average of 65 g") and E. Warner et G. Heath ("9 to 110 g CO‐eq/kWh by 2050")...
https://www.researchgate.net/publication/222817608_Life_cycl...
The popular YouTube channel The B1M has an interesting video on how Finland is tackling nuclear waste:
Finland might have solved nuclear power's biggest problem (2021): https://www.youtube.com/watch?v=kYpiK3W-g_0
And even after all that it's still far less expensive than remediating coal output.
Hoping to know enough and for sure about all this is... a hope.
Stating that we know what our descendants will need/do in a so distant future is even more funny.
They "considered" such facts using a somewhat light approach: 'Bob Loux, the executive director of the Nevada Agency for Nuclear Projects, expressed amazement that the US Department of Energy had only just carried out the "11th hour" drilling tests.
"It certainly looks like DoE has encountered a surprise out there, and it certainly speaks to the fact they haven't done the technical work they should have done years ago," he told the paper.
"It's going to have to cause some change of the design in the final analysis. It's going to impact the safety case."'
Oops...
They also "considered" those metal containers as adequate during the 1990's, then... (what, you think "they" are omniscient?)... problems related to brines and high temperature arose...
https://www.nwtrb.gov/docs/default-source/board/mrs_duquette...
https://www.nrc.gov/docs/ML0335/ML033500420.pdf
Oops...
It’s like complaining that a wool blanket is itchy so it might be better to catch hypothermia and die.
The plants are also located away from cities, so utilizing the waste heat for district heating is uneconomical.
How many more meltdowns per decade?