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Nuclear Chemistry: Fission

Added Sep 29, 2017 •

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nuclear fission in this video will Define fission and talk about how it is used for power and how it is used for nuclear weapons vision is when you play I Spy vintage smaller daughter nuclei this will generally occur when atomic number is greater than 90 nuclei neutrons ejected I have one example of a reaction shown here we have CF splitting into two daughter nuclei and also four neutrons special attention to these four neutrons because that's relatively important how this would relate first nuclear weapons because that's actually the simpler think of this crap and power but we must take into consideration when we're designing these weapons nuclear weapons and nuclear power rely on the fact the pigeon tends to be a chain reaction if you are given a certain Mass what we call the critical mass of material have you bombarded with neutrons you will cause a certain nuclei to split I split you get more neutrons electrons to other nuclei causing those to split and those ones will split trans well you get the point when does happen and when was it isn't controlled at all it happens very very very quickly what you get is a huge release of energy and this is what we call a bomb we have to do something start the Chain Reaction we have to start that bombardment typically the way that we do this is with some sort of what we call a conventional explosion maybe or something like that AT&T conventional explosion will cause a certain amount of neutrons to bombard the nuclei and will cause that to cause the atomic explosion so once again too Slim two masses together hitting a critical mass allowing nuclear bombardment to happen at the same time together this starts the chain reaction in the chain reaction and what causes the huge release of at and that is what causes large explosion that were used to seeing in videos and pictures and things of that sort is the giant mushroom cloud that you can actually dust and what happens is you create a vacuum and then as the air rushes back into it causes mushroom cloud to have obviously has great historical importance because we all know that it was deployed in World War II I thought it might be worth talking about the fact that these are very very different types of bonds depending on what you're using at the basic chemical principles the same and that's the most important for you to know for this class but maybe some stress from engineering standpoint to know that when we talked about having stock has a large quantities of nuclear weapons are of a very large variety of types most infamous to all of us very different in both cases you can see a little boy we have the two pieces of uranium that are not at critical mass and other words on their own those two aren't going to explode then we slam them together with a conventional chemical explosive this allows a critical mass to happen so they were Chain Reaction can take hold and doesn't just fizzle out into starts the bombardment by is a gun type of assembly for the sort of obvious reasons that it sits in a tube bird Gun Lake the second talk about is the one that we deployed in Nagasaki was just called fat man and actually using plutonium or uranium you can actually use different types of radioactive material in the bomb and the way that this work was actually have this compress plutonium core which event caused the bombardment there was all of around the whole outside Mitchell explosives what is conventional explosives something I think you should do in your own time is cuz it's very long washing a double speed to jump through it's an interesting little video idea where someone took all the nuclear weapon explosions that we have ever had and they map it on a little toy that goes off and you can watch the first scarf you can wash these to go off countries get the nuclear weapons and start testing them and how often they are going off and where they are going off a very interesting thing to put on the background while you're doing something else homework and it's interesting it's worth a quick me and her over to now enough about destruction what can we do this actually useful in non-destructive with this and of course it is nuclear power there's a big difference between nuclear power and nuclear weapons nuclear weapons all the time because we need to be able to harness that power as we need it slow and controlled fashion wear one we are going to cost you John's of Destruction into we can actually harness the energy that is coming off to do this what we need to do is keep the reaction from being exponential chain reaction to set off Conventional Weapons constantly to get these had to happen but we don't want that exponential increase so what we do is we set up a system where it for after we set up the initial Neutron all the nutrients are allowed to move forward so we can absorb or somehow make sure that some of the neutrons cannot go further on to get more nuclei to undergo fission the way that we do this is what we call control rods so sure you can see that we have these control rods so that they are able to go on and this keeps the reaction going because are allowed to go on it keeps it from being exponential difference between Bob's and power it's just the ability to control it but there's a lot of problems when this comes from an engineering standpoint so that you're able to control the reaction keep it everything from moving too fast able to absorb some of these excetera we do this is my vacation that we have lots of water D200 that's another terminology for it heard of heavy water reactors all of his water except the hydrogen have an extra Neutron and so it's heavy will say is make sure that their actions consistently cold and otherwise we would start melting that control to the way we do that is using control rods to keep the chain reaction and check we don't let it get too hot because we only let so much as those neutrons continue on we also use huge huge cooling systems and usually that consists of a water and using steam to then turn the turbines which also gives us some power to you'll find that a lot of nuclear power plants are actually built by water. So that we have a consistent supply of water that can be used the other big problem here is it creates a lot of radioactive waste we can't really get around this until we get to the point where we can use Fusion so there's no real good solution for this at the moment we basically did a hole in the mountain and bury it there's also the places where they basically digging giant Lake and put it there there's been suggestions about dumping it into the ocean because I think it would be ideal if the ocean is so large that it will delay I think we shall see the obvious problems there's no discussion about sending it to space which would be a great idea except for the fact that oftentimes are aircraft that we send up and if we had an aircraft go and it exploded it was filled with radioactive waste there would be some obvious problems and so we're really kind of stuck with this one and burying it somewhere is about our best solution at the moment so review vision is the splitting of nuclei using a nuclei in the next video this generally produces neutrons which allow a chain reaction to take place if you have enough Mass this Chain Reaction will continue to happen forever and it's uncontrolled we now have a nuclear weapon if it's allowed to go on that I've been very controlled manner where everything is tightly controlled he is tightly controlled we can use

Uploaded by Laura Houston.

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Nuclear Chemistry: Fission

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