I'm going to talk about nuclear fallout, the residual radioactive material, from weapons tests and the far reaching environmental effects it can have. First of all, there's 2 primary kids of detonation, air burst and round burst, both with different implications on how the fallout behaves. Air bursts occur when the bomb detonates above the ground and in this case, the fission products from the bomb vaporize and are drawn up quickly into the stratosphere. Depending on winds and other meteorological conditions, they settle back toward the earth more slowly than ground bursts. In a ground burst, the ground around the bomb is vaporized and drawn up with the mushroom cloud, but because its chunks of rock or whatever was on the ground, the particles bond to the radioactive particles from the bomb and up to 50% of the fallout falls to the ground within 24 hours afterwards.
If viewed from the "solution to pollution is dilution" aspect, the air burst has less fallout since it falls slower and thus is more spread out. The larger particles from the ground burst contaminate the area immediately as well as spread through the air like an air burst. The largest example of an incident like this was the Castle Bravo incident in 1954, where a theoretically 6 Mt air burst bomb test produced a 15 Mt explosion and coupled with poor weather conditions, spread farther and had much worse impacts than were anticipated. Pretty gruesome radiation exposures of nearby island and more in the Pacific Ocean became a national incident which led to attempts to end atmospheric nuclear bomb tests, finally done in 1963.
In 1963, the Limited Test Ban Treaty was signed by the U.S., Soviet Union, and Great Britain and tests moved underground, though France and China continued atmospheric testing for 11 and 17 years, respectively. There are also radioactive fallout concerns from these, just not as environmentally destructive. From 1952 to 1962, there is evidence showing an increase in cancers in counties around the Nevada nuclear test site. Iodine-131 is the main contributor to thyroid cancer since thyroids tend to gather iodine that enters the body. Additionally, caesium-137 and strontium-90 pose significant health concerns from the fallout because of their half lives and decay modes (30.17 y and 1.176 MeV beta and 28.79 y and 0.546 MeV beta, respectively).
-Michael
(Too ironic not to add)
Because the Government basically irradiated people, have they ever compensated anyone for these incidents?
ReplyDeleteCheck it out.
DeleteThe Radiation Exposure Compensation Act establishes lump sum compensation awards for individuals who contracted specified diseases in three defined populations:
Uranium miners, millers, and ore transporters – $100,000;
“Onsite participants” at atmospheric nuclear weapons tests – $75,000; and
individuals who lived downwind of the Nevada Test Site (“downwinders") – $50,000.
There is a US Department of Justice website about this. Is 50,000$ worth living near a nuclear testing site??
http://www.justice.gov/civil/common/reca
Interesting. Here is a higher risk of cancer, and lots of money!!! I dont guess much else could have been done. And alot of the affects that are known today, were not known as extensively as back then. Cant change the past, can only learn from it and test the unknown a little more safely.
DeleteExactly, that link says the RECA was passed in 1990 so 50,000 then is $93,784.69 now according to a simple Google inflation search. Still hard to compensate for life or pain with a hundred grand but it's something. I personally don't think it's worth it but that's open to personal judgement.
DeleteAlso, if the irradiation from the test site started in 1952 and the act was passed in 1990, that's almost 40 years difference. With a normal life expectancy of about 73 years, that means over half of the people even affected are probably dead by now (especially if there was a significant rise in cancer rates).
When you say the 6 MT bomb generated a 15 MT blast, do you mean the equivalent effect the bomb had? So due to the poor weather and air burst explosion, it spread out and affected an area what they predicted a 15 MT explosion would do?
ReplyDeleteNot really the weather, it actually came out to a simple interactions mistake They used lithium to absorb neutrons and generate an alpha particle and tritium, the tritium then fusing with deuterium. In the calculations, they only accounted for lithium-6 doing this since lithium 7 absorbs thermal neutrons to lithium-8 which decays after a few seconds to an alpha, tritium, and a neutron (a few seconds being enough delay to not participate in the explosion). In the test they used natural lithium (7.5% Li-6, 92.5% Li-7), apparently they didn't know or forgot that lithium 7 can absorb thermal neutrons and not decay for a few seconds but it also can absorb fast neutrons (typically found in a nuclear detonation....) and instantly decays to an alpha, tritium, and neutron alpha particles. The tritium fused with deuterium as predicted but the extra neutron then fissioned more uranium than intended. The US also tested a 4 MT bomb called Castle Romeo which when detonated, produced a 11 MT blast.
DeleteIf the Limited Test Ban Treaty had not been passed, what do you think might have happened? I like to imagine that Senior Design classes would have been blasted out of every syllabus in existence.
ReplyDeleteOh it'd still be there but it'd probably change to something like: plan a bomb test using "xx basic spec" bomb spec and determine who is in danger, how much, and mitigate it. Meaning, we might actually get to develop a detonation test like everyone automatically assumes we do.
DeleteBut to answer your first question, it'd be bad. Really bad. We were pretty good about our tests but Russia was particularly bad about theirs. We detonated 2 of the top 5 largest, number 4 and 5. Russia holds 1,2 and 3 spots on that list. The general summary is we built our smaller because we had better accuracy, Russia built theirs bigger to ensure they hit what they wanted to since they couldn't/didn't build them more accurate.
Correction, US holds 5th largest, Russia holds 1-4*
DeleteSince the meteorological patterns are very complex, software is needed to do calculations regarding radiation fallout. At Oak Ridge National Lab they have a super computer (TITAN) which is used for meteorological patterns.
ReplyDeleteThis is a very interesting cross between the meteorological and nuclear effects. Definitely shows the importance of such crossovers. I wonder what sort of protocol and regulations there were regarding the meterological x nuclear fallout. Was there not any sign moments before testing that would have clued in to scrub the testing? What were the operable ranges and how far were they out of these ranges?
ReplyDeleteThere were signs, actually. From Wikipedia (as reliable of a source as that is), "In the de-classified film "Operation Castle", task force commander Major General Percy Clarkson points to a diagram indicating that the wind shift was still in the range of "acceptable fallout", although just barely.
DeleteThe decision to carry out the Bravo test under the prevailing winds was made by Dr. Alvin C. Graves, the Scientific Director of Operation Castle. Graves had total authority over detonating the weapon, above that of the military Commander of Operation Castle."
Like we talked about in class Friday, the weather predictions are much more accurate today than they were in the past, unfortunately.
Great incorporation of photos into your blog entry! What's more troublesome is that the Soviets detonated a hydrogen device with a yield of 50 megaton TNT. Does Tsar Bomba ring a bell? Being part of the generation we are, us students don't understand the horrifically large scale of these demonstrations - much less the amount of damage the radionuclide release did to the environment.
ReplyDeleteOh yeah, Tsar Bomba is very familiar. Big enough for the shockwave still to be heard on the ...3rd time around the globe? From what I can tell they cleared the area around the immediate bomb site but damage from that was hard to prevent, just from the shockwave. Thanks for an idea for my next blog post!
Delete16 rads is on the low end of radiation exposure, but definitely enough to do some cellular damage. It'd take about 50 rads from a single dose to get some immediately detectable effects (lower white blood cell count, etc). Not to detract from the unnecessary exposure, but just to give an idea.
ReplyDeleteMostly significant due to annual background dose being ~200 millirad? If it's 10 rad over 10 years, you're getting 5 times what you'd normally get from background. I guess it's up to hormeisis to tell us if it's significant or not but it probably isn't good for you.
DeleteThis post makes me wonder what would be the amount of nuclear bombs needed to cause a worldwide extinction. Not to sound like a crazy person but when people talk about nuclear weapons they usually say things like "a nuclear holocaust". Knowing the amount of weapons detonated in certain parts of the world, and their damage to the neighboring area, the amount of nuclear bombs needed to annihilate the entire population of the world would have to be quite a few I would think. Unless of course each bomb went off in key areas of the world which supplied the population with much needed resources like water and crops.
ReplyDelete