# Radiation, etc.



## JCFarnham (May 16, 2012)

I'd imagine this might be on the periphery of a lot of people's interests. However, in the event that some one out there has studied this kind of stuff, I'd like to see if I can get some solid information on this.

I'm looking into nuclear holocaust scenarios for a story I have in the planning stages at the moment*. If asked this question in a number of place and done some research in to the matter myself, but I haven't yet got a decent answer for _how long would it take until the kind of radiation you get from nuclear fallout has decayed to a relatively safe level_. 

I'm beginning to wonder whether this is a "no body knows" question, because I've even tracked down some now public cold war era documents, stuff on Chernobyl... no where does anyone attempt to define when it would be quote-unquote safe. 

Of course, I could be looking in all the wrong places. I still need to such for some of the Bikini Atoll studies.


*I want to make it clear. This isn't generic post-apocalypse fiction, so don't you worry. It just so happens that a large scale nuclear event is in the past of the setting haha

ADDITIONAL: I've spent time looking into long term effects of fallout, the genetic bits, the illnesses, all that fun stuff, and its safe to say that I can handwave it all. I'm mainly asking this question so I can clarify my time line. Better to be safe than sorry. Do it now, less work later.


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## Penpilot (May 16, 2012)

Check out this article it gives all the half-lives of the various elements of fallout. I the reason it's hard to find a direct answer is because it depends on what radioactive element is contaminating the area. Some have half-lifes of a few years others thousands of years. And I would venture a guess each radioactive element affects living organisms in varying degrees. But I'm no expert, not even close.

Radioactive Fallout | Worldwide Effects of Nuclear War | Historical Documents | atomciarchive.com

There's also this one from a survivalist forum, but grain of salt with this one. 
Nuclear fallout radiation decay rate - Survivalist Forum


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## Ravana (May 17, 2012)

JCFarnham said:


> _how long would it take until the kind of radiation you get from nuclear fallout has decayed to a relatively safe level_.
> 
> I'm beginning to wonder whether this is a "no body knows" question



It falls into the "nobody knows with much certainty" category, at the very least. How radioactivity affects any given individual seems to be highly idiosyncratic—even when directly exposed, and even to "dangerous" isotopes… and some isotopes are so "safe" they get injected into human bodies in medical procedures.

For instance: on Jan. 12, 2010, a man named Tsutomu Yamaguchi died at age 93. He had been in Hiroshima on business on August 6, 1945; in spite of serious burns, he returned home two days later… to Nagasaki. This time he wasn't directly injured; instead, he got the joy of helping search the ruins for survivors. And while he _did_ die of cancer, I'd have to say that, all things considered, it probably had little to do with the radiation he was twice exposed to: he beat the life expectancy at birth of a Japanese male by 14 years—for one born in the year he died. Considering when he was born, he probably beat it by something closer to thirty years. 

If it weren't for the memorials, there wouldn't be a single bit of physical evidence today that either city had ever been bombed. While they've unquestionably been cleaned up, they were never even completely abandoned. People managed to survive there anyway. Not all, to be sure… but it wasn't like they were dropping like flies, either, once those exposed directly to the blasts had all died or recovered, or else they _would_ have been abandoned. 

Then there's the celebrated case of the factory workers who fell ill or died as a result of exposure to radium in the paint they were using to make watch dials, over the course of a decade, from 1917 to 1926. What's less well known is that radium continued to be used this way up into the '60s… with no further deaths. Marie Curie had worked with radioactive materials for 36 years by the time she died—_before_ they were known to be dangerous. (Her husband was long dead: he was run over by a horse-drawn cart. Which should give you some idea just how _much_ earlier he died.)

I'd say you can safely hand-wave just about all of it—as far as the "safe" end goes. If you wanted to know how long something would remain _hazardous_, then you'd have to worry more about what sort of radioactive incident you were looking at, what types of radiation and radioactive materials were released, how much of same, the types of radiation any remaining materials released (both those spread by the incident and those irradiated by it—two very different things), half-lives, and so on… because you might otherwise be in danger of having it remain dangerous for _longer_ than it actually would be plausible for it to. Remember that the longer the half-life, the _less_ dangerous something is (compared to another substance giving off the same type of radiation)… because the longer the half-life, the less of it there is actually radiating anything. 

In contrast, for the other direction all you would need to do is say that the weather blew a certain amount of the fallout away, rains carried a certain amount of the residual material off and transported a certain amount more deep into the water table (which, depending on underground water transport, might then be carried away), et cetera, along with fiddling with initial amounts and concentrations as necessary. In other words, it can become "safe" just about as fast as you want it to, so long as you don't want it to happen in weeks or months. Hell, you could do it even then, if you wanted the event to be overlaid by a meter-thick pyroclastic flow from a volcano, though I'm guessing that would defeat your purpose. Might be a tad on the sterile side… but it wouldn't be radioactive.


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## gavintonks (May 17, 2012)

well Hiroshima is a perfect timeline they built the city immediately after, it has to do with how far off the ground the bomb explodes.
Chernobyl is an accident and the radiation leaked for years however the are is not a wasteland but a thriving ecosystem with enough radiation to create x rays.
Radiation is a natural product of the earth and is absorbed and filtered as any other natural product even oil is natural despite people making issues about it

salt water sued to clean the radiation destroys the ground and makes it almost impossible to grow stuff, cactus's mutated in hiroshima and produced plants of bright yellow and red which were previously green, so only the main blast incinerated people in the blast zone up to 1km 2km was death and near death 5km was nausea and sickness death within 5 days beyond the blast zone some people lived up to 60 years on


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## gavintonks (May 17, 2012)

new yotk had a bigger problem with asbestosis from buildings with dust infected with the fibres and whole buildings were shredded and encased in concrete and buried, so depends what the accumulated problems are


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## JCFarnham (May 17, 2012)

Well, initially we would be talking about incidents from at least the majority of nuclear plants in the first world sooo isotopes of Iodine, Caesium and Strontium? Those kind of things are fairly common, and fairly serious for a variety of reasons. I'm only going by our good friend wiki mind you 

I'm kind of banking on the atmosphere taking a bit of a hit and therefore allowing more UV through to the surface. 

So climate change is a big thing I'm trying to figure out in relation to the fallout. It is however far enough into the future of this time line that over population and over industrialisation could have caused a few more dust bowls. On top of natural disasters, people finding better places off world and the previous mentioned issues of course. So the sort of aesthetics I'm looking for in this future Earth are actually kind of Dune inspired to be completely honest, but with less arid-ness and less focus on water (though it would be fun for that to be a traded commodity).


Typical of this setting is that everything could be sorted in a couple of decades if any one cared. They could put up a world wide shield array like a big pair of uv blocking sunglasses. They could part terraform the Earth back to "day zero" as it were. But no one cares enough. There are bigger and better things to do in the universe than cry over the loss of one little mediocre blue-green marble, or so the opinion goes. The majority human government would rather spend money and resources on other things.

Anyway! It's good to know you guys think I could handwave a good proportion of this. Well as long as I make mention of cancers and sterility I should be good really.


And as you can probably tell I'm looking to destroy the economy in the process.


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## Butterfly (May 17, 2012)

Reminds me of a book I once read for GCSE. - Children of the Dust by Louise Lawrence - set in the Cotswolds at the start of a nuclear war and spans several decades after it. I'd recommend it as a read, if you haven't heard of or read it before.


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## Benjamin Clayborne (May 17, 2012)

In other words: Things stay radioactive and dangerous exactly as long as the plot needs them to be


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## gavintonks (May 17, 2012)

probably your radiation will cure cancer,  would look at skin burn and cell mutation


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## Ivan (May 19, 2012)

I don't think that the sorts of isotopes we are talking about would damage the atmosphere, those tend to be rather heavy elements that don't go up into the high atmosphere where all the radiation-blocking goes on. However, you could have clouds of airborne isotopes like what happened with Chernobyl. Those would eventually fall out (hence the term) but you could bend the rules and have such things raining down unstable isotopes for decades.


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## ascanius (May 19, 2012)

I thought about going into first order kinetics and nuclear decay.  I had an entire page of equations for you but....unless you know anything about chem didn't think they would be useful.  If you know the half life for the substance and the nuclear equation you can approximate with some degree of accuracy how long it would take for radiation levels to be safe.

that would be in a controlled environment.  after a nuclear blast your also going to have to look at the distance above the surface, wind direction and speed, and a few other factors others have mentioned.


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## Ivan (May 19, 2012)

There are so many factors just to the actual radiation levels, then you get into the biological impact, which is not well understood and appears to vary widely among the few people that have been exposed to moderate doses. I'd say that Benjamin has the best answer...


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## Chargo (May 26, 2012)

By nuclear holocaust I'm assuming you mean a full on 80s MAD style exchange between a two nations like Russia and the US, not a limited exhange such a hiroshima event or something like what would happen if India-Pakistan went at it. In a MAD style exchange, basically the world would die because there would be no chance of advanced life living on the surface for very long. I think the novel _The Road_ does a fairly good job of depicting this. Lets assume though that some underground vaults survived the initial holocaust also had some seeds/ supplies or whatever to get civilization back on its feet. It would take anywhere from a week or so to a couple moths before the surface radiation levels were fine. But the atmosphere would be recked, and most livestock/crops would be dead. It could potentially take up to a few years for the atmosphere to get back to "liveable" (it'd still suck though) and about 10-20 years to make a full comeback. Obviously a lot of plants and animals would go extinct so maybe there wouldnt be cattle or redwoods anymore. This is less due to the radiation itself and more because of the huge ash clouds and acid rain.


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## JCFarnham (May 26, 2012)

Chargo said:


> By nuclear holocaust I'm assuming you mean a full on 80s MAD style exchange between a two nations like Russia and the US, not a limited exhange such a hiroshima event or something like what would happen if India-Pakistan went at it. In a MAD style exchange, basically the world would die because there would be no chance of advanced life living on the surface for very long. I think the novel _The Road_ does a fairly good job of depicting this. Lets assume though that some underground vaults survived the initial holocaust also had some seeds/ supplies or whatever to get civilization back on its feet. It would take anywhere from a week or so to a couple moths before the surface radiation levels were fine. But the atmosphere would be recked, and most livestock/crops would be dead. It could potentially take up to a few years for the atmosphere to get back to "liveable" (it'd still suck though) and about 10-20 years to make a full comeback. Obviously a lot of plants and animals would go extinct so maybe there wouldnt be cattle or redwoods anymore. This is less due to the radiation itself and more because of the huge ash clouds and acid rain.



Specifically I'm talking about a large containment failure in a network of nuclear plants world wide (because the people who populate the setting are so Scifi everything has to be networked don't you know haha). But to be honest 7-10+ chernobyls over the course of a month isn't going to be massively pretty... if anything for the economy. 

I mostly agree with your ideas, but would like to draw your attention to the thriving ecologies around known fall out zones. Chernobyl is possitively buzzing with plants and wildlife (even growing through the cracks in the reactor walls. Though an awful lot of the wildlife is partially sterile depending on diet ect.). I know the Japanese bomb incidents are rather small in comparison to what I'm talking about, but if you went to either city, you'd be hard pressed to find any evidence aside from monuments. 

Basically I'm reading up on the subject to see if I can safely say "five decades (or something similar) on..." when it comes to talking about the settings history. There will be people living on the surface, and in "sky cities" (this can be handwaved due to advanced tech levels to be honest). 

The main issue is that the setting is Earth. If it was any other planet anywhere else in the universe I could do what I want, but just because it's so close to home (pun only partially intended) to not do ANY research would be a massive oversight. The tone of the piece demands it, even if I'm writing a mostly space opera universe. 


Oh I know an interesting fact about some of the nuclear testing grounds around the world. Where once there were cactii with green flowers, they're now typical yellow and red. How weird is that?  I'm definitely going to look into how the world ecology works after this event. So far I know I want extensive desert and limited resources, enough for people to live on and more or less trade but enough for the human government to say "blow it. who cares about that dying rock any way, we have other places in the universe to be"


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## Chargo (May 27, 2012)

Ahhhh ok now I get it. You can pretty much disregard most of what I said about the everything on the surface dying part.  Whereas a nuclear exchange would have high levels of immediate radiation and destruction, most of the actual destruction would come from the fallout blotting out of the sky and the high temperatures involved in an exchange (which would be similar to many simultaneous volcanoes like the Krakatoa event that nearly put humans into extinction). 

In the scenario you describe radiation levels would be much lower, but also last a much longer time. Most radioactive compounds released would actually become safe isotopes in around 3 years, with most birth defects among animals (humans too) occurring during that time period. That time period would be pretty horrific, and awful. After that some isotopes that would last longer would still be around, up to thirty or 60 years. For example Chernobyl occurred in 1986, and the half-life of the remaining worrisome isotopes (Strontium-90 and Caesium-137) is about 30 years so if you're story takes place 50 years after the event only about 10% would be left. Also those levels would respond well to Thyroid cancers (the main side affect of nuclear radiation other than radiation poisoning) so a lot of people would die immediately due to their Thyroid being destroyed and then you'd have high levels of Thyroid cancer up to 30 yrs later (idk if you actually want to use this, but it might be good as a minor plot detail or to show you did your hw cause I know how nit-picky Sci-Fi people can get).

Btw about the ecology, definitely some weird stuff goes on in radiated are, you should look at the red forest in chernobyl. Plus as it is scifi I feel you could get away with some creepy stuff going on near the old reactors, the creepiness of Chernobyl is definitely what makes it so intriguing. One last thing, if your people live in high-altitude sky cities they're going to have to adapt to the higher levels of radiation in the upper-atmosphere.


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