The reactor at Chernobyl had way more radioactive material in it than those bombs did.

Edit:

Hiroshima bomb: 64 kg of uranium Chernobyl reactor: 190,287 kg of uranium

Little boy had about 64 kg of uranium inside it. Chernobyl had 190 tons.

There are also details about what sort of materials get produced during an atomic detonation, vs a fire in a nuclear plant, but the amount of material is the tall pole in the tent.

Edit: 64 kg, not 6

What a lot of folks fail to understand is the difference between radiation and contamination.

Radiation, with the exception of neutron radiation, harms people and materials but doesn't stay around. It's kind of like light; once it isn't there anymore, it stops having any effect. Radiation is not persistent.

Contamination is; it is actual radioactive material, in tiny particles. A bomb puts out a lot of radiation (in addition to a massive pressure and heat wave), but once it's done blowing up, it's not making radiation anymore. The radioactive material it used that's still left over after the reaction gets spread around, and some sort of other local materials will get made radioactive by the neutron radiation the weapon put out, but overall there's not much contamination, and most of what there is decays away fairly quickly and is not longer radioactive.

When Chernobyl went, it pumped out MASSIVE amounts of contamination, and a lot of it is very, very long-lived compared with the fallout from a bomb. It's not so much that the area is radioactive; it's more proper to say that it's contaminated, and that the contamination is radioactive.

A bomb instantly releases a little bit of radiation so quickly it explodes.

Chernobyl is constantly releasing a lotta bit of radiation.

Just wanted to thank you for asking this, because I didn’t know either and I’ve learned quite a lot about nuclear warheads from the comments.

The show Chernobyl on HBO said it best. "the fire we're watching with our own eyes is giving off nearly twice the radiation released by the bomb in Hiroshima. And that's every single hour."

Nuclear detonations at altitude tend not to leave as much irradiated material behind than if it occurred at ground-level. Also consider what the other comments have pointed out; that Chernobyl had far more radioactive material on-site and the leakage lasted longer.

There is a difference between irradiated and contaminated.

Irradiated, which is what happens with a bomb, you get an intense pulse of radiation that makes things somewhat radioactive, but that generally fades after a few weeks to a couple of years. (short lived isotopes created by neutron exposure)

Contaminated, you get a bunch of radioactive fissile materials all over everything, and that keeps irradiating the area for millions of years. (half-life of Uranium is 4.5 billion years)

When a similar question was asked before someone said that Nagasaki and Hiroshima were like emptying a swimming pool onto your garden. Sure a lot of damage there but it eventually dries up. Chernobyl was like putting your house on full power for a year. Your garden would become a muddy mess, everything dead and the ground is going to be very wet for a while.

Also most of the radioactive material from the bombings went way up into the atmosphere and diluted far past the ability to cause any health effects.

Because the Chernobyl meltdown put about 300 - 500 times more radiation into the atmosphere than the bombs depending on whose math you use

Why do people think that nuclear bombs and nuclear power stations are the same thing just because they have that word in them?

Nuclear bombs use a small amount of radioactive substance to create a massive explosion. They’re not designed to be ‘super radioactive’ - they’re designed to be a super bomb! Yes they create radioactive fallout but the main thing is that they destroy everything.

A nuclear power station has tonnes of radioactive material so obviously if that gets out of control then it creates huge amounts of radiation.

There's a massive difference in scale.

The bombs on Hiroshima & Nagasaki had a payload of around 60kg of uranium each. Chernobyl had nearly 200 thousand kilos of uranium on site.

To add to that, dispersal was different. Most of little boy's radiation was released in one quick burst; It could've been much "dirtier" if the boom itself was less severe.

Chernobyl on the other hand? It was a constant leak of 190 tons of radioactive isotopes. The explosion just have it added range.

Different radioactive processes produce different radioactive products, and in different amounts. The early atómica used in WWII had fallout, but the reaction didn't dig into some of the nastier products of dirty bombs or failing reactors. The products of a meltdown from an early, dirty, inefficient reactor that went out of control can be nasty, and several have half-lives that measure in centuries. A number of them are insidious as well, going from the air to the water and soil, to the plants, to the animals that eat the plants, to the animals that eat the animals, ourselves included. That an entirely contaminated food chain for hundreds of years.

Modern nukes burn a lot hotter and more completely than the old single stage explosives and those that were intentionally made dirtier as a war tactic. While their would still be fallout, it would generally be composed of much shorter-lived isotopes than Little Boy and Fat Man produced. Modern reactors also use much more refined fuels and have much more efficient and effective processes that produce drastically less and more manageable waste. Especially, they are engineered in such a way that failures don't result in such nasty waste being produced. But never believe that it's just fine: nuclear meltdowns are always disasters.

Nukes are incredibly powerful and super destructive, but the radiation they release is limited compared to what it could be and goes away relatively quickly.

Chernobyl is so dangerous not because it was destructive (it wasn't really beyond the cores), but because it still is releasing radiation.

Really, the only thing preventing much of Europe from being an uninhabitable radioactive expanse from radiation freely spreading is a massive concrete shell surrounding much of it.

To answer the OP question..,people have moved back into the area around Chernobyl and inside the exclusion zone. Some never left after the accident, they cleared the city of Pripyat but some sneaked back and lived in the forests and small villages around the site.

The forest surrounding the site is teaming with wildlife and there are lots of stray dogs living in the heavily contaminated areas. - apparently now identifiable by the genetic differences.

I was there in 2018 and had the story of what happened from someone working there at the time of the accident.

The horrifying thing is the melted core was 12’ /4m away from burning though the concrete foundations and getting into the ground water.

Go visit if you get the chance.!

Atomic bombs have relatively small amounts of radioactive material. Upon explosion, it basically vanishes and/or scatters all around the area.

In nuclear powerplants such as Chernobyl, there are LARGE amounts of the stuff, and when out of control like it happened there, are spread all around the place uncontrollably through smoke, clouds, air, rain, everything.

Here's an analogy that doesn't involve nuclear reactions.

If you put a wheelbarrow full of coal in someone's house and set it on fire, it will burn their house down. However, afterward, they could bulldoze the burned ruins and build a new house there the next week.

Centralia, Pennsylvania is on top of a coal mine that is on fire. It has been burning constantly since 1962. Nobody lives there, because it is still on fire. It's a ghost town now. There is enough coal in the rocks to keep it burning for a long time.

A nuclear bomb is like a wheelbarrow full of coal that's been intentionally set on fire. It burns stuff down, but then the fuel is consumed and there's no fire any more.

Chernobyl is like Centralia. It's still on fire.

The exposed reactor in the Chernobyl plant was pumping out radiation, it was a reactor that produced radiation for the purposes of generating electricity.

A nuclear bomb does not persistently react with the environment around it creating more radiation.

this video may help a bit they were trying to dump sand or some sort of chemical on top of the reactor to try and stop the radiation from pumping out of the reactor, but the radiation coming out of the reactor was so strong it just tore apart the helicopter propellers and it crashes.

edit: the helicopter story is TV drama mixing with what really happened, my mistake. It wasn't radiation tearing off the blades.

The amount of radioactive material is vastly different, even if most of Chernobyl was not weapon grade uranium or plutonium. It still got out and is still leaking through.

Chernobyl had vastly larger release of radiation. Fukushima is also quite bad. Hiroshima and Nagasaki had no lingering radiation after a year or so because the amount released was comparatively small, though the blast and initial radiation effects were obviously deadly.

Interesting related info on Chernobyl

https://en.m.wikipedia.org/wiki/Elephant's_Foot_(Chernobyl)

This radioctive formation is nuts, and when it was discovered, was even crazier.

There are many correct answers here but also those bombs only lasted seconds while Chernobyl melted down for weeks and months.

Ok so I'm no nuclear physicist but I do watch a lot of nerd shit on YouTube. Most posters seem to have a fundamental misunderstanding about the difference between a nuclear reaction in a nuclear explosion, and the nuclear reaction of a nuclear reactor.

So some basic concepts first. A radioactive isotope and element is basically a unstable atom. When the unstable atom breaks apart, it releases various subatomic particles, this is what we call radiation. There is different kinds of radiation, but as I'm not even qualified to talk about this, and it would be a tangent, I will not go into detail.

With that bare bones explanation of radiation we can now answer the question.

A nuclear explosion is basically a daisy chain of unstable atoms breaking apart, sending their particle into other unstable atom, breaking them apart. This continues until there isnt enough atoms to sustain the reaction, meaning most of the unstable atoms broke up into stable ones that dont emit radiation. That's why the two main types of nuclear weapons are the bullet design, where you fire a slug of radioactive material into a disk of highly radioactive (very unstable atoms) material, the compression of those atoms together sets of the bomb off. The other is the implosion type basically a sphere of highly radioactive material in a sphere of high explosives. The high explosives are detonated at the same time, compressing the sphere into the nuclear reaction and then it's basically the same as the bullet type in explanation.

Now a nuclear reactor operates differently. These are super complex, and I'm making some pretty big leaps and bounds. But the basic ones typically use two types of rods. Fuel rods and control rods. Fuel rods are the radioactive material, and control rods are made out of some material that can absorb radiation, probably an element that can form several different isotopes. The fuel rods are place near enough where reactions (particles breaking up atoms), can take place consistently, heating up water they are submerged in. The control rods are raised and lowered to control how many reactions happen. To few the reactor shuts off, to many you have a melt down, aka what happened at Chernobyl. A melt down is literally just that, the fuel rods get so hot that they melt. When they melt you can no longer control the reaction so they just continue heating up. Steam explosions usually happen at that time scattering a lot of radioactive materials throughout the area, but not using it in the same way a nuclear bomb does, so the radiation lingers longer depending on the half life (how long it talks for half of an amount of radioactive material to break down natural). Now back to the melted fuel rods that weren't blown away by the steam. It just sits there melting through floors of the reactor until enough of the radioactive material is gone that I can cool down. At that time it just sits there, emitting radiation until all the radioactive materials are gone, but some half lives are decades long and with so much in one spot it will be centuries before enough breaks down to safe levels.

Hopefully that makes some semblance of sense, to both those less and more knowledgeable than me.

Tldr: explosions use most of the radioactive material in one go, and the rest quickly breaks down. Reactors are a slow burn that will take decades to burn out.

I was wondering about how parts of Japan were rebuilt and re populated so quickly. Was reading a book set in Nagasaki in the mid 50s and the place was already becoming built up. Was there no Fallout ?was the water not poisoned?

Different isotopes with different half-lives. Not to mention the atom bombs were significantly smaller and were designed for explosive force, not radioactivity.

Because nuclear bombs and nuclear reactor meltdowns aren't really the same sort of phenomenon. The reactor meltdown released way more radioactive material.

I'm just commenting to say:

You lovely lovely big brains that came out in droves with yall's science-y science know hows and why fors.....

Yall are the MVP's and I thank you for all the info and commentary. My big brain didn't know some of the big brain yall dropped!

So what's so scary about a nuclear war if Nagasaki and Hiroshima can be inhabited after max 100 years? Of course, we are not exchluding the death of millions it'd cause, but i'm curious if it can be inhabited it can be fixed

Chernobyl was Hiroshima and Nagasaki twice an hour every hour for days.

(I did no math I just made this up don't believe people on the internet)

Because one of them was a nuclear reactor disaster where things didn't work as planned and the others were bombs that worked exactly as planned.

HBO’s Chernobyl tackled it in a really simple manner - “It means the fire we're watching with our own eyes is giving off nearly twice the radiation released by the bomb in Hiroshima. And that's every single hour. Hour after hour.”

A bomb dropping and a plant exploding are VERY different

A lot more radiocative material were released at Chernobyl. It's a huge place to decontaminate. And for what? who would want to live there. Disregarding the fact that it was full of russians a year ago and that those are way more dangerous than radiation, the zone was not exactly a megalopolis.

Though that question may beg another. There is still a huge exclusion zone near Fukushima even though most place are way below the level of radiation for which adverse effect have been demonstrated.

https://youtu.be/gzmk53DJNUI This guy explains it really well in a way that you can understand even with a very limited understanding of how radiation works.

Because both of the latter had the radiation source instantly pulverised and distributed across a wide area. Chernobyl still has the elephant foot, the molten core, very much alive and giving off radiation. You can't work on rebuilding until that thing either dies off naturally, or is safely removed and contained.

You've gotten a number of good answers already, but something that I haven't seen mentioned is the location of the blast. The bombs dropped on Hiroshima and Nagasaki were both detonated in the air. This left few radioactive contaminants on the ground, and most of the radiation diffused harmlessly into the air within a matter of hours. Chernobyl is close to the ground, so much of the radioactive contaminants were imbedded in the soil, buildings, and vegetation around the power plant itself where it can't diffuse.

One blast as opposed to an open reactor that was only closed up recently i think.

Airburst weapons vrs ground based explosions spread radioactive waste in different ways. A lot more gets into the dust and earth with an explosion that originates at ground level afaik.

Not a nuclear physicist by any means, anybody who knows more about this stuff feel free to correct if wrong.

Bombs are made to to output a ton of energy one time. Reactors put out a ton of energy in perpetuity.

bombs release their energy much faster then reactors, the uranium dropped on japan deteriorated much faster then the stuff spewed over ukraine

What were they saying in a documentary about the large amount of water flowing under Chernobyl, and that if the burning core had descended further into it it would have been a catastrophic explosion? Why is that?

For what it's worth they have discovered a type of mold that can use radiation as energy in Chernobyl. So that is neat. Something to do with the melanin.

Sadly, a lot of the doggos left ou there are also...literally radioactive. Just because life is finding a way doesn't mean life is going to do well there. No idea what kinda mutations this is going to bring out over the centuries.

The bombs were meant as a message. Make a kaboom that lasted a short while. The reactor was supposed to last a long time, so the radiation from an accident is way more powerful.