Not just worst case scenario "rates", but the scenarios themselves. What is the worst case scenario from a completely unmitigated core meltdown versus whatever the most extreme failure mode of, say, a coal plant?
Pollution from coal power kills about a million per year, and that's not counting accidents. I don't know why you'd want a "completely unmitigated meltdown," but even if terrorists rent a 747, hoist an active reactor, and drop it onto the middle of Manhattan, it will kill less than the non-failure mode of coal plants during the same year.
from the less biased (depending on the metallicity of your hat) World Health Organization:
"Ambient (outdoor) air pollution in both cities and rural areas was estimated to cause 4.2 million premature deaths worldwide per year in 2016; this mortality is due to exposure to small particulate matter of 2.5 microns or less in diameter (PM2.5), which cause cardiovascular and respiratory disease, and cancers.
People living in low- and middle-income countries disproportionately experience the burden of outdoor air pollution with 91% (of the 4.2 million premature deaths) occurring in low- and middle-income countries, and the greatest burden in the WHO South-East Asia and Western Pacific regions. The latest burden estimates reflect the very significant role air pollution plays in cardiovascular illness and death. More and more, evidence demonstrating the linkages between ambient air pollution and the cardiovascular disease risk is becoming available, including studies from highly polluted areas.
WHO estimates that in 2016, some 58% of outdoor air pollution-related premature deaths were due to ischaemic heart disease and strokes, while 18% of deaths were due to chronic obstructive pulmonary disease and acute lower respiratory infections respectively, and 6% of deaths were due to lung cancer.
Some deaths may be attributed to more than one risk factor at the same time. For example, both smoking and ambient air pollution affect lung cancer. Some lung cancer deaths could have been averted by improving ambient air quality, or by reducing tobacco smoking."
...
"In addition to outdoor air pollution, indoor smoke from household air pollution is a serious health risk for some 3 billion people who cook and heat their homes with biomass fuels and coal. Some 3.8 million premature deaths were attributable to household air pollution in 2016. Almost all of the burden was in low-middle-income countries. Household air pollution is also a major source of outdoor air pollution in both urban and rural areas."
a few notes: Coal has two atmospheric externalities: particulates and C02 emissions. As the WHO notes, it can be difficult to attribute deaths to particulate pollution, and it can be even harder to then attribute that death to some source of particulates (they could be released by coal, or diesel engines, or any number of chemical reactions, though coal is particularly dirty when compared to other modern fuels). Climate change will affect lives, but it may be even more difficult to accurately attribute as a cause of death. Did rising temperatures play a role in recent middle eastern conflicts? Probably. Does this mean that climate change has already killed people in Syria and Yemen? That's a difficult question, at least to me.
No, I was able to find stats about fossil fuels. What I question is that it would be less harmful to drop a reactor right into the middle of a city. Remember, my question was about worst case scenario for nuclear, which the very pro-nuclear crowd here has so far been unable to describe on the many occasions that nuclear is hailed here as our saving grace. They instead point to Fukushima and Chernobyl and say "see, there's nothing to worry about."
What, you want an accurate physical simulation of a nuclear reactor falling onto Manhattan, Marvel comics style?
Well, considering that an actual nuclear bomb going off on Hiroshima killed "only" <150,000 people, I find it pretty unlikely a falling reactor will kill half of Manhattan. So, there.
Glib response aside, I want a credible description of worst case scenario for nuclear disaster. The probability of such an event increases greatly if there are many plants, particularly if there are plants in nations which go into decline or plants built in highly corrupt or inept nations. So how many people die from the initial event? How much residual radiation? How far does it spread? How many people are displaced? Are food supplies effected? It sounds like you haven't really thought it through all the way. My personal belief is that people are not to be trusted with technology with such high stakes. Especially with the onset of climate catastrophe within the century ensuring the decline of our society.
Didn't Chernobyl almost make a huge swath of Europe uninhabitable? Wasn't that the takeaway from the miniseries? That a lot of people gave their lives to prevent an unfathomable disaster?
That's a stretch. The Exclusion Zone[1] is about 2600km^2 (1000 sq mi) but it's only declared uninhabitable, there are people living there (though not saying it's a wise move to settle down there).
There are some areas outside that which is also deemed dangerous, but that's the order of magnitude we're talking about.
For reference, Europe covers an area of about 10 million km^2 (almost 4 million sq mi).
Also note that we don't have a good handle on how lower levels of radiation affects us, and there's discussion around if the prevailing method[2] to estimate exposure effects over-estimates the effects at lower exposures.
Sorry, brain seemed to filter away the crucial "almost".
However it goes back to how "intermediate" levels of radiation affects us. Even if the water had caused the remaining cores to blow up as well[1] then it's still not clear just what the impact would be[2].
I might not be remembering correctly, but I thought they had to tunnel under it to stop the core from burning down into the water table which would spread the nuclear disaster far and wide. Not to stop the steam explosion.
The worst case scenario from fossil fuels is not failure at a coal power plant. Even mining coal is more dangerous, and deaths directly from coal pollution dwarf mining accidents. But the worst case scenario is climate change that strongly affects hundreds of millions to billions of lives. Depending on location, it would take many "unmitigated core meltdowns" at nuclear power plants to have a similar effect.
