When we think of “nuclear winter,” we typically think of radioactive fallout in the sky caused by massive amounts of nukes going off and when it rains this down, everything dies. And we are wrong. Nuclear winter actually refers to firestorms all over the planet—caused by the detonation of nukes—reaching the stratosphere and spreading out, thus blocking out the sun from the Earth’s surface. Its synonym is “nuclear twilight,” which gives the idea of what lighting would take place. The hypothetical scenario includes a cooling of the Earth’s surface.

Alas, this is a hypothetical scenario since massive amounts of firestorms haven’t happened on Earth during our scientifically recorded time. And it is nowadays questioned on probability.

In the story, the characters refer to the overcast sky above their heads as “nuclear winter.” But remember, they use language that is the real world, everyday things we actually say—just as they called the infected “zombies.” The sky above, is it only over North America or not, since the characters have no way of knowing, being cut off from such information since leaving Boston (source being the news) and especially Mount Weather.

Chernobyl’s nuclear power plant explosion ascended radioactive material one mile (over 5,000 feet) into the sky, which is in the troposphere. This material spread out into what’s called “radiation clouds,” which then moved over other countries in accordance with the winds.

In the story, there are over fifty “Chernobyl” explosions, most of which are concentrated in parts of the USA. See this blog post that shows the map of cooling pools. Most of these are melting down, meaning exploding, but the characters do not know when each is going. Mazy and Ben traveled a corridor that wasn’t near any nuclear power plants to be on the safe side.

Why do these plants explode? Hydrogen. Chernobyl and Fukushima both exploded from hydrogen whereas Three Mile Island (1979) narrowly averted this by venting out the hydrogen. When the cooling pools are on fire, they release hydrogen, which forms into what’s called a hydrogen bubble—a ticking time bomb. When it explodes, that is a nuclear power plant meltdown, versus a nuclear power plant fire, which also happens. (Chernobyl’s fire burned for ten days.)

The nearest meltdown from the Black Hills of South Dakota is around 500 miles away. Kraków, Poland is about 500 miles (800 km) from Chernobyl. This happens to be a unique city for the 1986 disaster because what took place was surprisingly well documented for the era and being under a communist dictator. Kraków’s scientists found some workarounds to the communist bureaucracy and managed to get an iodine program going.

Radiation causes cancer, right? The evacuated people at Chernobyl got cancer from the disaster, right? Shockingly, radiation exposure and cancer are not an entirely true correlation…weird, huh? A 2005 report, then another in 2015 from the UN verified it. Outside the workers directly exposed, the over-18-year-old population evacuated from Chernobyl does not have any greater rates of cancer than any other population does. There were no other demonstrated increases in the rates of solid cancers, leukemia and non-cancerous diseases from the radiation exposure. Surprise! Weird, huh? We were so sure of that cause-and-effect. The characters believe it is true, and they no longer can Google anything to learn otherwise.

However, there is a confirmed direct correlation between people who were under 18 at Chernobyl during the disaster and thyroid problems, including thyroid cancer, later in their lives. The numbers are impressive for pretty much all the now-grown people who were children and adolescents during the 1986 disaster.

This was because a massive amount of iodine isotopes (Iodine-131) was released in the disaster’s spew out of radioactive material including in the radiation clouds. Iodine-131 falls as dust. This radionuclide has a half-life of only eight days. Since the USSR was too busy lying and covering up the disaster, they did not engage in a program to protect the not fully grown, the obviously most susceptible. This program would be giving a dosage of iodine, which is what they did in Kraków, Poland 500 miles away once they detected the higher rates of radiation coming their way from the radiation cloud—despite no information on the disaster occurring in the Ukraine, good job scientists!

For about 8 days, avoid standing water, green leaf produce, and cow’s milk. (This was an era in which they did not routinely wash their fruit and veg, unlike us today.) Further, give iodine to the population, especially those not fully grown as well as pregnant women. We can get iodine in any camping kit nowadays since it helps with killing off organic nasties in wildlife water as well.

Chernobyl spewed out onto the land a lot more than iodine isotopes. Cesium-134 (half-life 2 years 70 days) and cesium-137 (30.17 years) are the two biggies, and they omit beta and gamma radiation, things you want to avoid in life. These nasties remain more localized, unlike I-131. Cs-137 is why there is still an 18-mile exclusion zone surrounding the power plant.

For the characters’ sakes, fortunately, cesium remains localized to the meltdown areas as Chernobyl and Fukushima have shown. The characters are also far from the Mississippi and Missouri Rivers that could possibly be carrying anything. Fukushima’s disaster has shown that freshwater fish are contaminated even ten years later with Cs-137, previously believed to be a water-soluble radionuclide. The scientific community continues to learn through the disasters, which for our characters is not a safe feeling.

What’s in the heavy overcast sky above the Zoners? How far up does that overcast go? Is it from nuclear firearm detonations, firestorms from the nukes, the nuclear power plant meltdowns, firestorms from the meltdowns, or combos of all of them? All they know so far is it’s constantly there, and it always looks like it’s about to rain. That tells us it is probably pretty low, and that’s good news. We do not want that all the way up into the stratosphere and definitely not covering the whole Earth, or shit would be an even worse scenario than what they are innocently heading right into for Book 8, Generation of the Damned.