1 00:00:00,850 --> 00:00:03,220 The following content is provided under a Creative 2 00:00:03,220 --> 00:00:04,610 Commons license. 3 00:00:04,610 --> 00:00:06,820 Your support will help MIT OpenCourseWare 4 00:00:06,820 --> 00:00:10,910 continue to offer high quality educational resources for free. 5 00:00:10,910 --> 00:00:13,480 To make a donation or to view additional materials 6 00:00:13,480 --> 00:00:17,440 from hundreds of MIT courses, visit MIT OpenCourseWare 7 00:00:17,440 --> 00:00:18,313 at ocw.mit.edu. 8 00:00:21,173 --> 00:00:23,590 TEACHING ASSISTANT (TA): So if you guys don't remember me, 9 00:00:23,590 --> 00:00:24,460 I'm one of your TAs. 10 00:00:24,460 --> 00:00:26,418 I'm TA number three, that's what I call myself. 11 00:00:26,418 --> 00:00:27,240 I'm Ka-Yen. 12 00:00:27,240 --> 00:00:29,740 And I'll be teaching your lesson today because, well, Mike's 13 00:00:29,740 --> 00:00:30,460 in Russia. 14 00:00:30,460 --> 00:00:32,320 So, yeah. 15 00:00:32,320 --> 00:00:34,715 Yeah, so I know you guys had your first exam 16 00:00:34,715 --> 00:00:35,590 a couple of days ago. 17 00:00:35,590 --> 00:00:36,370 How did that go? 18 00:00:40,210 --> 00:00:41,040 OK, sounds good. 19 00:00:41,040 --> 00:00:42,582 All right, so we won't talk about it. 20 00:00:42,582 --> 00:00:45,340 But because you guys just had a super intense exam, 21 00:00:45,340 --> 00:00:46,930 we just want to give you guys a break. 22 00:00:46,930 --> 00:00:48,310 So today, I'll be teaching you guys a little bit 23 00:00:48,310 --> 00:00:49,430 about nuclear energy. 24 00:00:49,430 --> 00:00:51,580 So this lesson won't be super in-depth. 25 00:00:51,580 --> 00:00:54,272 There won't be a lot of crazy intense math. 26 00:00:54,272 --> 00:00:56,230 Actually, there won't be any crazy intense math 27 00:00:56,230 --> 00:00:57,670 because we just want to give you guys a break. 28 00:00:57,670 --> 00:00:59,410 You guys are going to be starting up 29 00:00:59,410 --> 00:01:02,970 full cycle on Friday with really cool topics like stopping 30 00:01:02,970 --> 00:01:03,470 power. 31 00:01:03,470 --> 00:01:05,012 So for now, we're just kind of like-- 32 00:01:05,012 --> 00:01:06,190 it's a refresher. 33 00:01:06,190 --> 00:01:07,360 A couple of fun facts. 34 00:01:07,360 --> 00:01:08,950 A couple guys might already know some of the concepts 35 00:01:08,950 --> 00:01:10,570 that I'm mentioning, because you guys are intelligent people. 36 00:01:10,570 --> 00:01:13,235 But I walked into MIT not knowing a single thing 37 00:01:13,235 --> 00:01:14,110 about nuclear energy. 38 00:01:14,110 --> 00:01:16,830 I was like, I wish someone could have told me these things. 39 00:01:16,830 --> 00:01:19,440 So that's what I want to do for you today, OK? 40 00:01:19,440 --> 00:01:22,102 So I'm going to be talking about the functionality 41 00:01:22,102 --> 00:01:24,310 and the benefits and the problems associated nuclear. 42 00:01:24,310 --> 00:01:26,268 But first let's start with a very brief history 43 00:01:26,268 --> 00:01:27,050 in a nutshell. 44 00:01:27,050 --> 00:01:29,980 So between 1895 to 1945, that's really cool 45 00:01:29,980 --> 00:01:32,050 people were developing nuclear science. 46 00:01:32,050 --> 00:01:35,920 So people like Madam Curie or like Fermi, et cetera. 47 00:01:35,920 --> 00:01:38,685 They were all designing this nuclear science, 48 00:01:38,685 --> 00:01:40,810 like they were developing it, which is pretty cool. 49 00:01:40,810 --> 00:01:44,230 Most of this development happened between 1939 and 1945. 50 00:01:44,230 --> 00:01:48,950 Does anyone want to take a gander as to why? 51 00:01:48,950 --> 00:01:49,562 What? 52 00:01:49,562 --> 00:01:50,770 AUDIENCE: Manhattan Project? 53 00:01:50,770 --> 00:01:51,520 TA: Yeah, exactly. 54 00:01:51,520 --> 00:01:54,820 But what field of the Manhattan Project? 55 00:01:54,820 --> 00:01:56,130 AUDIENCE: Nuclear weapons. 56 00:01:56,130 --> 00:01:56,890 TA: World War two. 57 00:01:56,890 --> 00:01:57,420 Yeah. 58 00:01:57,420 --> 00:01:59,770 So World War two was happening during those times, 59 00:01:59,770 --> 00:02:02,380 and they were trying to develop the atom bomb, which 60 00:02:02,380 --> 00:02:04,390 is why the majority of nuclear science 61 00:02:04,390 --> 00:02:07,360 was developed between these like five or six years. 62 00:02:07,360 --> 00:02:09,259 Then 1945 to 1960. 63 00:02:09,259 --> 00:02:11,640 They've entered a phase of like, well, the war is over. 64 00:02:11,640 --> 00:02:13,270 Now what do we do with ourselves? 65 00:02:13,270 --> 00:02:16,390 So luckily we decided to redirect this science 66 00:02:16,390 --> 00:02:18,720 into using it for energy and harnessing it 67 00:02:18,720 --> 00:02:19,720 in a controlled fashion. 68 00:02:19,720 --> 00:02:22,210 So mainly the focus was actually for Naval submarines, 69 00:02:22,210 --> 00:02:25,840 but they also realize that we can use this for energy 70 00:02:25,840 --> 00:02:27,410 as well, for electricity as well. 71 00:02:27,410 --> 00:02:28,270 So there's a lot of really cool things 72 00:02:28,270 --> 00:02:29,812 that happened in between these years. 73 00:02:29,812 --> 00:02:32,920 So in 1951, the first nuclear reactor to produce electricity 74 00:02:32,920 --> 00:02:34,990 was the experimental breeder reactor, 75 00:02:34,990 --> 00:02:36,630 the EDR1 was developed and designed 76 00:02:36,630 --> 00:02:38,380 and operated, and actually kind of worked. 77 00:02:38,380 --> 00:02:39,460 It was created by Argonne National 78 00:02:39,460 --> 00:02:40,460 Labs, which is in Idaho. 79 00:02:40,460 --> 00:02:41,870 And they actually still exist. 80 00:02:41,870 --> 00:02:44,650 So if you want to go work there this summer, you totally can. 81 00:02:44,650 --> 00:02:46,870 And then in 1953, President Eisenhower, 82 00:02:46,870 --> 00:02:49,240 he created something called atoms for peace. 83 00:02:49,240 --> 00:02:51,400 So this is just a program that advocated 84 00:02:51,400 --> 00:02:53,590 using nuclear for things that were peaceful, 85 00:02:53,590 --> 00:02:57,640 such as electricity instead of nuclear weapons and stuff. 86 00:02:57,640 --> 00:03:00,700 Also 1953 was the creation of Mark 1. 87 00:03:00,700 --> 00:03:03,750 So Mark 1 is the first prototype Naval reactor that was created. 88 00:03:03,750 --> 00:03:05,200 It was created in March. 89 00:03:05,200 --> 00:03:07,540 And then finally in 1954, the first nuclear powered 90 00:03:07,540 --> 00:03:09,340 submarine, the USS Nautilus was launched, 91 00:03:09,340 --> 00:03:10,690 and is up and running. 92 00:03:10,690 --> 00:03:13,098 So lots of cool things happened between this time. 93 00:03:13,098 --> 00:03:14,890 But the real heyday of nuclear was actually 94 00:03:14,890 --> 00:03:17,830 between 1960 to 1975. 95 00:03:17,830 --> 00:03:19,750 So during the span of 15 or so years, 96 00:03:19,750 --> 00:03:22,270 this was the real commercial energy boom. 97 00:03:22,270 --> 00:03:25,660 People like Westinghouse were creating nuclear reactors. 98 00:03:25,660 --> 00:03:27,850 I think the first one was called Yankee Rowe. 99 00:03:27,850 --> 00:03:30,790 It's a 250 megawatt electric nuclear power 100 00:03:30,790 --> 00:03:33,820 plant, which is not insignificant for a time 101 00:03:33,820 --> 00:03:35,273 like the 70s. 102 00:03:35,273 --> 00:03:37,690 So other different companies and other different countries 103 00:03:37,690 --> 00:03:38,740 were doing this as well. 104 00:03:38,740 --> 00:03:41,413 basically, there was this huge boom in nuclear energy. 105 00:03:41,413 --> 00:03:43,330 So if you look at this little chart over here, 106 00:03:43,330 --> 00:03:46,120 this is nuclear reaction construction 107 00:03:46,120 --> 00:03:47,300 throughout the years. 108 00:03:47,300 --> 00:03:49,830 So if you look in this little chunk, 109 00:03:49,830 --> 00:03:51,580 you can see what a massive peak there was. 110 00:03:51,580 --> 00:03:53,440 This was when everyone was building nuclear reactors, 111 00:03:53,440 --> 00:03:55,060 people thought it was super jazzy, 112 00:03:55,060 --> 00:03:57,187 and everyone tried to jump on that. 113 00:03:57,187 --> 00:03:59,770 Unfortunately, all good things have to come to an end, though. 114 00:03:59,770 --> 00:04:03,880 From 1975 to 2002, which is about this chunk over here, 115 00:04:03,880 --> 00:04:05,242 you can see a massive decline. 116 00:04:05,242 --> 00:04:06,700 And you can see that nothing really 117 00:04:06,700 --> 00:04:09,010 happened between the 90s and the 2000s, other than the fact 118 00:04:09,010 --> 00:04:09,930 that we were all born. 119 00:04:09,930 --> 00:04:12,880 But no new nuclear reactors were being 120 00:04:12,880 --> 00:04:15,250 commissioned during this time. 121 00:04:15,250 --> 00:04:17,980 And then today, we're kind of-- 122 00:04:17,980 --> 00:04:20,204 I say we're back, but basically we're 123 00:04:20,204 --> 00:04:21,579 entering what people like to call 124 00:04:21,579 --> 00:04:24,400 a nuclear renaissance, which is between this chunk over here. 125 00:04:24,400 --> 00:04:26,662 You can see that there's been a slight increase 126 00:04:26,662 --> 00:04:28,120 in nuclear reactors being produced. 127 00:04:28,120 --> 00:04:31,600 But basically there's been a whole new push for creating 128 00:04:31,600 --> 00:04:33,490 more advanced reactors. 129 00:04:33,490 --> 00:04:35,690 And currently, China, India, and South Korea, 130 00:04:35,690 --> 00:04:38,260 they are the main players in this game. 131 00:04:38,260 --> 00:04:41,320 So China itself has 32 operate reactors operating 132 00:04:41,320 --> 00:04:43,830 at the moment, and have 20 more commissioned, 133 00:04:43,830 --> 00:04:45,950 like literally right now, which is kind of insane. 134 00:04:45,950 --> 00:04:50,240 So yeah, do you guys have any questions about this? 135 00:04:50,240 --> 00:04:51,290 Great. 136 00:04:51,290 --> 00:04:53,863 So what causes nuclear resurgence? 137 00:04:53,863 --> 00:04:56,530 This is the perfect time to talk about why nuclear power's cool. 138 00:04:56,530 --> 00:04:58,227 Again, you guys probably know this. 139 00:04:58,227 --> 00:04:59,810 But the main reason is sustainability. 140 00:04:59,810 --> 00:05:01,730 So right now we've entered a phase in time 141 00:05:01,730 --> 00:05:03,230 where people are starting to realize 142 00:05:03,230 --> 00:05:05,040 that we've done damage to our environment, 143 00:05:05,040 --> 00:05:06,200 we've got to fix this. 144 00:05:06,200 --> 00:05:07,700 So global warming is a thing. 145 00:05:07,700 --> 00:05:09,440 I promise you, it's actually a thing. 146 00:05:09,440 --> 00:05:11,240 And basically, we're looking for a way 147 00:05:11,240 --> 00:05:13,730 to produce electricity without creating such a large carbon 148 00:05:13,730 --> 00:05:14,390 footprint. 149 00:05:14,390 --> 00:05:15,470 So if you look at this chart over here, 150 00:05:15,470 --> 00:05:17,330 you can see that this is where nuclear 151 00:05:17,330 --> 00:05:19,280 lies in the amount of carbon that it 152 00:05:19,280 --> 00:05:20,960 produces per-- what's the unit? 153 00:05:20,960 --> 00:05:22,832 Per gigawatt hour of electricity. 154 00:05:22,832 --> 00:05:24,290 When you look at that in comparison 155 00:05:24,290 --> 00:05:26,690 to coal and natural gas, which is our two primary sources 156 00:05:26,690 --> 00:05:29,203 of energy at the moment, you can see that this is definitely 157 00:05:29,203 --> 00:05:29,870 more attractive. 158 00:05:29,870 --> 00:05:31,610 So the statistic is actually that nuclear 159 00:05:31,610 --> 00:05:36,260 creates 75 times less carbon emission than coal does, 160 00:05:36,260 --> 00:05:38,840 and 35 times less than natural gas does, 161 00:05:38,840 --> 00:05:40,490 which is incredible and amazing. 162 00:05:40,490 --> 00:05:42,740 So that's the main reason why we're going for nuclear. 163 00:05:42,740 --> 00:05:45,992 But there's other kinds of really good reasons. 164 00:05:45,992 --> 00:05:47,450 One is the amounts of power output. 165 00:05:47,450 --> 00:05:49,700 You guys actually calculated this yourself in pset 1. 166 00:05:49,700 --> 00:05:52,910 You know just how much power or energy comes out 167 00:05:52,910 --> 00:05:54,830 from one fission reaction. 168 00:05:54,830 --> 00:05:56,550 So just so you guys can double check 169 00:05:56,550 --> 00:05:58,130 that you got that statistic right in your pset, 170 00:05:58,130 --> 00:05:58,610 it turns out that 171 00:05:58,610 --> 00:06:00,740 It turns out that you get 3.5 million times more 172 00:06:00,740 --> 00:06:02,953 energy than burning one kilogram of coal does. 173 00:06:02,953 --> 00:06:04,370 So you can see that you definitely 174 00:06:04,370 --> 00:06:06,290 need a lot less fuel in a nuclear reactor 175 00:06:06,290 --> 00:06:10,810 than you do in a normal coal burning reactor. 176 00:06:10,810 --> 00:06:13,700 And then finally the last thing would be energy security. 177 00:06:13,700 --> 00:06:15,530 So one of the good things about nuclear 178 00:06:15,530 --> 00:06:17,905 is that it can serve as a good baseload source of energy. 179 00:06:19,702 --> 00:06:21,410 So if you're working in the energy sector 180 00:06:21,410 --> 00:06:22,610 you probably see this chart all the time 181 00:06:22,610 --> 00:06:24,860 of like time versus like energy that's being consumed. 182 00:06:24,860 --> 00:06:27,650 And it's kind of like this fluctuating little mass that 183 00:06:27,650 --> 00:06:30,080 stays fairly constant, but at certain times of the day 184 00:06:30,080 --> 00:06:31,880 you need more energy than usual. 185 00:06:31,880 --> 00:06:34,700 So this is just the energy demand during the day. 186 00:06:34,700 --> 00:06:37,460 That's what this chart kind of crudely depicts. 187 00:06:37,460 --> 00:06:40,280 So nuclear power is able to provide a good baseload source. 188 00:06:40,280 --> 00:06:42,830 That means it can provide conserve energy at a really 189 00:06:42,830 --> 00:06:44,700 high level all the time. 190 00:06:44,700 --> 00:06:46,520 So this is why we kind of want to replace 191 00:06:46,520 --> 00:06:48,020 coal and natural gas with nuclear, 192 00:06:48,020 --> 00:06:50,185 because it can take this role. 193 00:06:50,185 --> 00:06:51,560 Other alternative forms of energy 194 00:06:51,560 --> 00:06:53,300 might be better for the environment, it might be safer, 195 00:06:53,300 --> 00:06:55,530 and things like that, but it's not really able to do this. 196 00:06:55,530 --> 00:06:58,072 So for example, if you wanted to replace all the coal burning 197 00:06:58,072 --> 00:07:01,400 fire plants with solar panels, if it's not sunny that day, 198 00:07:01,400 --> 00:07:03,230 you're kind of out of luck, right? 199 00:07:03,230 --> 00:07:06,080 Like you can't produce energy if it's not sunny outside. 200 00:07:06,080 --> 00:07:07,045 Similar for wind. 201 00:07:07,045 --> 00:07:08,420 If it's not windy outside, you're 202 00:07:08,420 --> 00:07:09,890 not getting any electricity. 203 00:07:09,890 --> 00:07:11,390 Luckily for nuclear, it doesn't have 204 00:07:11,390 --> 00:07:13,890 to rely on any of these factors. 205 00:07:13,890 --> 00:07:16,097 You can continuously produce energy. 206 00:07:16,097 --> 00:07:16,885 Right? 207 00:07:16,885 --> 00:07:18,260 So do you guys have any questions 208 00:07:18,260 --> 00:07:20,620 about what I've mentioned? 209 00:07:20,620 --> 00:07:21,930 Awesome. 210 00:07:21,930 --> 00:07:24,305 So now we'll talk a little bit about reactor types. 211 00:07:24,305 --> 00:07:26,430 I'll just tell you guys about some of the main ones 212 00:07:26,430 --> 00:07:27,720 and how they work. 213 00:07:27,720 --> 00:07:30,330 So how people like to divide up the reactor 214 00:07:30,330 --> 00:07:31,993 types is in generations. 215 00:07:31,993 --> 00:07:33,660 So generation one, which, is all the way 216 00:07:33,660 --> 00:07:36,558 over there, that refers to the trial reactors. 217 00:07:36,558 --> 00:07:38,100 These are the ones that didn't really 218 00:07:38,100 --> 00:07:39,880 produce all that much electricity at all. 219 00:07:39,880 --> 00:07:43,290 They're more proof of concept kind of things, 220 00:07:43,290 --> 00:07:45,630 so that would be like the Mark I that I 221 00:07:45,630 --> 00:07:47,130 mentioned to you guys earlier. 222 00:07:47,130 --> 00:07:48,540 Now we move on to generation two. 223 00:07:48,540 --> 00:07:52,980 So generation two is actually what most of US reactors-- 224 00:07:52,980 --> 00:07:55,390 the category that most US reactors fall into. 225 00:07:55,390 --> 00:07:59,400 So these were developed between the '70s and the '80s-ish, and 226 00:07:59,400 --> 00:08:02,047 these are the ones that are functioning mostly today. 227 00:08:02,047 --> 00:08:04,380 And then we have generation three, three plus, and four. 228 00:08:04,380 --> 00:08:05,640 So these are the new types of reactors 229 00:08:05,640 --> 00:08:06,840 that people are trying to build on 230 00:08:06,840 --> 00:08:09,090 to create several improvements, but we'll talk about them 231 00:08:09,090 --> 00:08:10,090 a little bit more later. 232 00:08:10,090 --> 00:08:11,760 OK? 233 00:08:11,760 --> 00:08:14,040 So I want to start off with light water reactors, 234 00:08:14,040 --> 00:08:15,510 because these are the reactors that 235 00:08:15,510 --> 00:08:17,310 are most common in the United States. 236 00:08:17,310 --> 00:08:19,220 So light water reactors, or LWRs, 237 00:08:19,220 --> 00:08:22,050 are mostly broken up into two subcategories: 238 00:08:22,050 --> 00:08:24,930 boiling water reactors and pressurized water reactors. 239 00:08:24,930 --> 00:08:27,510 So how you guys can think about reactors 240 00:08:27,510 --> 00:08:30,360 is that honestly they're just kind of glorified steam 241 00:08:30,360 --> 00:08:31,120 turbines. 242 00:08:31,120 --> 00:08:32,880 That's what they're doing. 243 00:08:32,880 --> 00:08:34,770 So let's start with boiling water reactors. 244 00:08:34,770 --> 00:08:38,100 So boiling water reactors, or BWRs, comprise about 21% 245 00:08:38,100 --> 00:08:41,440 of the reactors that are located and working in the United 246 00:08:41,440 --> 00:08:42,512 States. 247 00:08:42,512 --> 00:08:44,220 So it's a really, really simple mechanism 248 00:08:44,220 --> 00:08:46,020 and we can walk through that right now. 249 00:08:46,020 --> 00:08:49,680 So over here, this little nubbin right over here, 250 00:08:49,680 --> 00:08:51,152 this is the fuel core. 251 00:08:51,152 --> 00:08:52,860 So this is what the inside of a fuel core 252 00:08:52,860 --> 00:08:54,620 looks like, that picture over there. 253 00:08:54,620 --> 00:08:56,370 So the fuel core is basically just a bunch 254 00:08:56,370 --> 00:08:58,595 of rods of uranium, sometimes it's 255 00:08:58,595 --> 00:08:59,970 clad in something like zirconium, 256 00:08:59,970 --> 00:09:03,090 and there's also control rods to help slow down the process. 257 00:09:03,090 --> 00:09:05,420 So uranium undergoes what? 258 00:09:05,420 --> 00:09:06,220 AUDIENCE: Fission. 259 00:09:06,220 --> 00:09:07,030 TA: Yes, fission. 260 00:09:07,030 --> 00:09:08,572 So what gets released during fission? 261 00:09:08,572 --> 00:09:09,840 AUDIENCE: Heat. 262 00:09:09,840 --> 00:09:10,492 TA: And? 263 00:09:10,492 --> 00:09:11,617 AUDIENCE: Fission products. 264 00:09:11,617 --> 00:09:12,117 TA: Cool. 265 00:09:12,117 --> 00:09:12,630 And? 266 00:09:12,630 --> 00:09:13,020 AUDIENCE: Neutrons. 267 00:09:13,020 --> 00:09:13,937 TA: Neutrons, awesome. 268 00:09:13,937 --> 00:09:16,590 So those three things are all flying around 269 00:09:16,590 --> 00:09:19,680 inside the reactor core at the moment as the uranium undergoes 270 00:09:19,680 --> 00:09:20,550 fission. 271 00:09:20,550 --> 00:09:22,710 So the isotopes, we just kind of let them be. 272 00:09:22,710 --> 00:09:23,580 Like I don't-- 273 00:09:23,580 --> 00:09:24,720 I'm not completely sure what we do with them. 274 00:09:24,720 --> 00:09:27,220 We might filter them out, but I think they just kind of hang 275 00:09:27,220 --> 00:09:27,840 out there. 276 00:09:27,840 --> 00:09:30,750 The heat obviously goes to create power. 277 00:09:30,750 --> 00:09:32,460 We'll talk about that in just a second. 278 00:09:32,460 --> 00:09:34,230 But the neutrons come flying around. 279 00:09:34,230 --> 00:09:37,320 So those other neutrons can simulate other fissions, 280 00:09:37,320 --> 00:09:39,403 and the control rods are there to make sure 281 00:09:39,403 --> 00:09:40,820 that there's not too many fissions 282 00:09:40,820 --> 00:09:45,607 happening in the fuel core at a certain time. 283 00:09:45,607 --> 00:09:47,690 Anyway, going back to the heat, the heat that gets 284 00:09:47,690 --> 00:09:50,450 created during these nuclear fissions, that 285 00:09:50,450 --> 00:09:52,140 goes and heats up the water. 286 00:09:52,140 --> 00:09:54,463 So this is just one loop of water, basically. 287 00:09:54,463 --> 00:09:56,630 So the water flows through the core and heats it up. 288 00:09:56,630 --> 00:09:59,060 It creates steam so the steam goes and spins a turbine. 289 00:09:59,060 --> 00:10:00,110 The turbine creates electricity. 290 00:10:00,110 --> 00:10:01,737 And it comes back and gets recondensed. 291 00:10:01,737 --> 00:10:02,570 That's literally it. 292 00:10:02,570 --> 00:10:05,570 That's all that happens during a BWR. 293 00:10:05,570 --> 00:10:07,400 Yeah, that's actually just it. 294 00:10:07,400 --> 00:10:10,700 So a cool thing about the BWR is, because it's so simple, 295 00:10:10,700 --> 00:10:12,620 it's also incredibly-- well, not incredibly, 296 00:10:12,620 --> 00:10:14,245 but it is the cheapest option out there 297 00:10:14,245 --> 00:10:15,443 for creating nuclear power. 298 00:10:15,443 --> 00:10:17,360 One of the downsides is just that it might not 299 00:10:17,360 --> 00:10:21,043 be as energy efficient as it possibly could be, or not 300 00:10:21,043 --> 00:10:23,210 be able to create as much power as it possibly could 301 00:10:23,210 --> 00:10:25,110 if it was a cooler technology. 302 00:10:25,110 --> 00:10:26,060 But yeah. 303 00:10:26,060 --> 00:10:28,190 Oh, and another downside is that because we 304 00:10:28,190 --> 00:10:30,590 have the nuclear material interacting with the water 305 00:10:30,590 --> 00:10:32,720 and-- so this is a coolant pump. 306 00:10:32,720 --> 00:10:34,010 This is a coolant tube. 307 00:10:34,010 --> 00:10:36,800 This is basically connected to a lake or an ocean 308 00:10:36,800 --> 00:10:39,120 or some other source of cold water, 309 00:10:39,120 --> 00:10:41,143 and that runs through the primary loop 310 00:10:41,143 --> 00:10:43,310 to cool down the water and recondense it into steam. 311 00:10:43,310 --> 00:10:45,143 If there ever is a breach between these two, 312 00:10:45,143 --> 00:10:47,940 the chances of leaking nuclear material into the environment 313 00:10:47,940 --> 00:10:48,440 exists. 314 00:10:48,440 --> 00:10:52,347 Like it's not high per se, but with BWRs 315 00:10:52,347 --> 00:10:54,680 there is a higher chance of leaking radioactive material 316 00:10:54,680 --> 00:10:55,555 into the environment. 317 00:10:55,555 --> 00:10:57,640 So that's one of the downsides of BWRs. 318 00:10:57,640 --> 00:10:59,780 Do you guys have any questions about this? 319 00:11:02,900 --> 00:11:03,400 Awesome. 320 00:11:03,400 --> 00:11:05,525 So I just want to show you guys this picture again, 321 00:11:05,525 --> 00:11:07,310 because here's the underside of a BWR. 322 00:11:07,310 --> 00:11:08,490 I make it sound like it's super simple 323 00:11:08,490 --> 00:11:10,070 and like a walk in the park, but this is actually 324 00:11:10,070 --> 00:11:11,690 the amount of technology that goes 325 00:11:11,690 --> 00:11:12,830 into one of these reactors. 326 00:11:12,830 --> 00:11:14,000 Like look at all those wires. 327 00:11:14,000 --> 00:11:15,458 I don't even know what they all do. 328 00:11:15,458 --> 00:11:18,460 But it's kind of insane. 329 00:11:18,460 --> 00:11:21,140 So the next kind of reactor that falls under the light water 330 00:11:21,140 --> 00:11:23,810 reactor category is the pressurized water reactors. 331 00:11:23,810 --> 00:11:29,900 So PWRs are actually more important, if you will, 332 00:11:29,900 --> 00:11:30,770 than BWRs. 333 00:11:30,770 --> 00:11:33,050 So remember, BWRs comprise about 21% 334 00:11:33,050 --> 00:11:34,630 of the reactors in the United States. 335 00:11:34,630 --> 00:11:38,870 PWRs comprise about 60% of the reactors the United States. 336 00:11:38,870 --> 00:11:41,000 But they are functionally essentially the same, 337 00:11:41,000 --> 00:11:43,050 and it's just slightly more complicated. 338 00:11:43,050 --> 00:11:45,110 So over here we have our fuel core again, 339 00:11:45,110 --> 00:11:47,150 and again all it's doing is heating up water 340 00:11:47,150 --> 00:11:48,470 with its fission reactions. 341 00:11:48,470 --> 00:11:50,545 But this time this water is pressurized. 342 00:11:50,545 --> 00:11:51,920 So does anyone know why you would 343 00:11:51,920 --> 00:11:54,890 want to pressurize the water? 344 00:11:54,890 --> 00:11:55,390 Yeah? 345 00:11:55,390 --> 00:11:56,598 AUDIENCE: So it doesn't boil? 346 00:11:56,598 --> 00:11:57,480 TA: Yeah, exactly. 347 00:11:57,480 --> 00:11:58,470 So when you increase the pressure, 348 00:11:58,470 --> 00:12:00,762 you're also increasing the boiling point of the water, 349 00:12:00,762 --> 00:12:03,220 and that allows you to function at even higher temperatures 350 00:12:03,220 --> 00:12:05,520 than if you're working with a BWR, which gives you 351 00:12:05,520 --> 00:12:06,600 more energy efficiency. 352 00:12:06,600 --> 00:12:09,645 You guys will learn all about that in 2005, by the way. 353 00:12:09,645 --> 00:12:10,973 So yeah. 354 00:12:10,973 --> 00:12:12,390 It heats up this pressurized water 355 00:12:12,390 --> 00:12:14,820 and this pressurized water goes into a second loop which, 356 00:12:14,820 --> 00:12:16,000 again, just heats up water. 357 00:12:16,000 --> 00:12:16,990 That turns into steam, that spins 358 00:12:16,990 --> 00:12:18,448 a turbine that creates electricity, 359 00:12:18,448 --> 00:12:20,040 gets recondensed, et cetera. 360 00:12:20,040 --> 00:12:21,890 And that's, again, all that there really is. 361 00:12:21,890 --> 00:12:24,313 So one of the upsides of using a PWR is, like I mentioned, 362 00:12:24,313 --> 00:12:25,230 the higher efficiency. 363 00:12:25,230 --> 00:12:28,080 But also the chance of leaking nuclear material 364 00:12:28,080 --> 00:12:29,610 into the violent becomes mitigated. 365 00:12:29,610 --> 00:12:33,660 Because you have two separate loops with the nuclear fuel 366 00:12:33,660 --> 00:12:35,512 being more isolated from the environment, 367 00:12:35,512 --> 00:12:37,470 if there is a breach between the condenser loop 368 00:12:37,470 --> 00:12:39,120 and the secondary loop, not a big deal. 369 00:12:39,120 --> 00:12:40,410 Nothing really bad happens. 370 00:12:40,410 --> 00:12:42,577 You'd have to have breaches in both the loops, which 371 00:12:42,577 --> 00:12:44,660 is very unlikely to happen. 372 00:12:44,660 --> 00:12:45,210 Yeah. 373 00:12:45,210 --> 00:12:47,710 So do you guys have any questions about those two? 374 00:12:47,710 --> 00:12:48,366 Yeah? 375 00:12:48,366 --> 00:12:50,699 AUDIENCE: What's the standard like operating temperature 376 00:12:50,699 --> 00:12:51,840 of these kinds of reactors? 377 00:12:51,840 --> 00:12:53,882 TA: I'm not completely sure, but if you Google it 378 00:12:53,882 --> 00:12:55,950 you should be able to find it very easily. 379 00:12:55,950 --> 00:12:57,660 OK. 380 00:12:57,660 --> 00:12:59,160 So this next picture is, again, just 381 00:12:59,160 --> 00:13:00,840 to show you that like I make it sound really simple 382 00:13:00,840 --> 00:13:02,882 and like a walk in the park, but it's really not. 383 00:13:02,882 --> 00:13:03,965 There's a lot going on. 384 00:13:03,965 --> 00:13:06,090 So this picture over here is basically just showing 385 00:13:06,090 --> 00:13:08,340 that there are a lot of redundancy systems 386 00:13:08,340 --> 00:13:10,700 inside these reactors. 387 00:13:10,700 --> 00:13:12,927 Like we don't just have one single primary loop 388 00:13:12,927 --> 00:13:14,010 and if it fails, it fails. 389 00:13:14,010 --> 00:13:16,380 We actually have four at the same time, 390 00:13:16,380 --> 00:13:19,050 and this is just called the n minus two redundancy, something 391 00:13:19,050 --> 00:13:19,550 like that. 392 00:13:19,550 --> 00:13:22,130 OK? 393 00:13:22,130 --> 00:13:24,160 So the next kind is something much cooler. 394 00:13:24,160 --> 00:13:25,485 It's got a heavy water reactor. 395 00:13:25,485 --> 00:13:27,110 Actually it's just a little bit cooler. 396 00:13:27,110 --> 00:13:29,530 But the main heavy water reactor that everyone can kind of 397 00:13:29,530 --> 00:13:31,930 think of on their minds is CANDU, 398 00:13:31,930 --> 00:13:33,760 which is the one that's located in Canada. 399 00:13:33,760 --> 00:13:35,800 So the only difference between heavy water reactors 400 00:13:35,800 --> 00:13:37,883 and the light water reactors as I mentioned before 401 00:13:37,883 --> 00:13:40,558 is that it uses heavy water instead of light water. 402 00:13:40,558 --> 00:13:42,100 Does anyone know what heavy water is? 403 00:13:42,100 --> 00:13:43,330 AUDIENCE: Deuterium oxide. 404 00:13:43,330 --> 00:13:44,080 TA: Yeah, exactly. 405 00:13:44,080 --> 00:13:45,288 So it's just deuterium oxide. 406 00:13:45,288 --> 00:13:49,480 So remember-- I'm sorry, this might seem inane, 407 00:13:49,480 --> 00:13:52,390 but this is water, right? 408 00:13:52,390 --> 00:13:54,805 And this is heavy water, where the D is just 409 00:13:54,805 --> 00:13:59,020 a hydrogen with two atomic particles instead. 410 00:13:59,020 --> 00:14:02,620 So one proton and one neutron. 411 00:14:02,620 --> 00:14:05,650 So the reason why they decide to use heavy water instead 412 00:14:05,650 --> 00:14:07,780 of light water is because heavy water 413 00:14:07,780 --> 00:14:10,300 has a much lower absorption cross-section 414 00:14:10,300 --> 00:14:12,860 than light water does. 415 00:14:12,860 --> 00:14:16,210 So what this means is that when neutrons are flying around 416 00:14:16,210 --> 00:14:19,930 in the reactor there is a chance of it hitting a fission 417 00:14:19,930 --> 00:14:22,900 product and a piece of fissionable material 418 00:14:22,900 --> 00:14:23,950 and undergoing fission. 419 00:14:23,950 --> 00:14:26,380 But there's also a chance that the water that surrounds it 420 00:14:26,380 --> 00:14:27,620 will absorb that neutron. 421 00:14:27,620 --> 00:14:29,230 So if that neutron gets pulled out of the system 422 00:14:29,230 --> 00:14:30,850 you're not able to create any more fissions. 423 00:14:30,850 --> 00:14:31,900 This is actually kind of a bad thing 424 00:14:31,900 --> 00:14:33,820 because the whole point of nuclear reactors 425 00:14:33,820 --> 00:14:35,070 is to create heat and fission. 426 00:14:35,070 --> 00:14:37,820 So we don't want those neutrons to be absorbed. 427 00:14:37,820 --> 00:14:40,150 You can see, if you look at those statistics, 428 00:14:40,150 --> 00:14:41,710 you can see that the absorption cross 429 00:14:41,710 --> 00:14:47,200 section of H2 or deuterium is like 0.00052 barns, 430 00:14:47,200 --> 00:14:50,150 in comparison to H1, which is 0.332 barns. 431 00:14:50,150 --> 00:14:53,400 So I'm bad at math, but I think it's like 600 times less, 432 00:14:53,400 --> 00:14:55,760 right? 433 00:14:55,760 --> 00:14:56,260 Maybe? 434 00:14:56,260 --> 00:14:58,390 Anyway, so you can see why deuterium would 435 00:14:58,390 --> 00:14:59,830 be a good option for this. 436 00:14:59,830 --> 00:15:02,080 So because it's absorbing less-- 437 00:15:02,080 --> 00:15:04,960 because it has a chance of absorbing less neutrons as it 438 00:15:04,960 --> 00:15:06,760 undergoes its processes, you're actually 439 00:15:06,760 --> 00:15:09,340 able to use a lower enriched uranium, which is really great 440 00:15:09,340 --> 00:15:12,070 because that lowers fuel costs. 441 00:15:12,070 --> 00:15:12,730 Yeah. 442 00:15:12,730 --> 00:15:15,407 But the main downside of this is that, even though you're 443 00:15:15,407 --> 00:15:17,740 lowering your fuel costs, deuterium is really expensive. 444 00:15:17,740 --> 00:15:20,068 It's about 1,000 or so dollars per kilogram, 445 00:15:20,068 --> 00:15:22,360 which is kind of ridiculous because a kilogram of water 446 00:15:22,360 --> 00:15:24,470 is really not much at all, you know? 447 00:15:24,470 --> 00:15:27,520 So even though you're counteracting the lower fuel 448 00:15:27,520 --> 00:15:30,580 costs with higher water cost. 449 00:15:30,580 --> 00:15:32,982 Also, because you're using your reactor 450 00:15:32,982 --> 00:15:34,690 with lower enriched uranium, you actually 451 00:15:34,690 --> 00:15:36,520 have to change out your fuel more often. 452 00:15:36,520 --> 00:15:38,775 That fuel gets spent more quickly 453 00:15:38,775 --> 00:15:40,660 and I'll describe that in just a second, 454 00:15:40,660 --> 00:15:43,030 and therefore you just have to keep replacing it 455 00:15:43,030 --> 00:15:45,520 more often than you would for a normal light water reactor. 456 00:15:45,520 --> 00:15:47,140 Cool? 457 00:15:47,140 --> 00:15:49,283 Questions about this one? 458 00:15:49,283 --> 00:15:50,700 Oh, I forgot to mention, but aside 459 00:15:50,700 --> 00:15:53,400 from that, everything else with the heavy water reactors 460 00:15:53,400 --> 00:15:58,260 and the PWRs, they're the same mechanisms. 461 00:15:58,260 --> 00:16:00,810 And finally we're going to move on to breeder reactors. 462 00:16:00,810 --> 00:16:02,920 So breeder reactors are a really cool idea, 463 00:16:02,920 --> 00:16:05,380 and they were most popular between like 464 00:16:05,380 --> 00:16:09,400 the '50s and the '60s-ish in the very beginning of creating 465 00:16:09,400 --> 00:16:10,570 nuclear reactors. 466 00:16:10,570 --> 00:16:12,220 So what breeder reactors are are, 467 00:16:12,220 --> 00:16:13,300 again, they're essentially the same thing 468 00:16:13,300 --> 00:16:15,467 as light water reactors I mentioned you guys before. 469 00:16:15,467 --> 00:16:17,410 But instead, now there's two little chunks 470 00:16:17,410 --> 00:16:18,402 of extra material. 471 00:16:18,402 --> 00:16:20,860 So do you guys know what the difference is between fissile, 472 00:16:20,860 --> 00:16:23,310 fertile, and fissionable material is? 473 00:16:23,310 --> 00:16:25,130 Cool. 474 00:16:25,130 --> 00:16:32,110 All right, so all right, let's start with fissile material. 475 00:16:37,850 --> 00:16:41,650 So fissile material is basically just the material 476 00:16:41,650 --> 00:16:44,200 that is willing to undergo fission with a thermal neutron. 477 00:17:15,453 --> 00:17:16,277 OK. 478 00:17:16,277 --> 00:17:17,819 So basically when the thermal neutron 479 00:17:17,819 --> 00:17:20,290 gets absorbed by this fissionable material, 480 00:17:20,290 --> 00:17:22,500 it's going to undergo a fission. 481 00:17:22,500 --> 00:17:24,155 Makes a lot of sense, right? 482 00:17:24,155 --> 00:17:25,530 So do you guys happen to remember 483 00:17:25,530 --> 00:17:26,990 what the energy of a thermal neutron is? 484 00:17:26,990 --> 00:17:28,515 You guys calculated this in pset 1. 485 00:17:28,515 --> 00:17:29,015 Huh? 486 00:17:29,015 --> 00:17:30,600 AUDIENCE: 1 eV? 487 00:17:30,600 --> 00:17:31,620 TA: Lower than that. 488 00:17:31,620 --> 00:17:32,520 AUDIENCE: 0.025? 489 00:17:32,520 --> 00:17:34,190 TA: Yeah, 0.025 eV. 490 00:17:34,190 --> 00:17:35,430 Like super low energy. 491 00:17:38,208 --> 00:17:40,250 And while we're at it, how do you calculate this? 492 00:17:46,580 --> 00:17:48,380 Bozeman constant times T. Cool? 493 00:17:48,380 --> 00:17:48,880 Whew. 494 00:17:51,730 --> 00:17:53,770 So main examples of fissile material 495 00:17:53,770 --> 00:17:56,590 would be U235 and plutonium 239. 496 00:17:56,590 --> 00:17:58,540 There's four in total, but those are 497 00:17:58,540 --> 00:17:59,820 the two most important ones. 498 00:18:05,930 --> 00:18:06,430 OK. 499 00:18:06,430 --> 00:18:11,380 So this is the main fuel that is inside a nuclear reactor, 500 00:18:11,380 --> 00:18:13,103 but it's not all just U235. 501 00:18:13,103 --> 00:18:15,520 Like you guys have heard of-- oh, shoot, what's it called? 502 00:18:15,520 --> 00:18:16,803 Enrichment, right? 503 00:18:16,803 --> 00:18:18,220 Enrichment is basically the amount 504 00:18:18,220 --> 00:18:21,400 of fissile material versus the amount of other fissionable 505 00:18:21,400 --> 00:18:22,000 material. 506 00:18:22,000 --> 00:18:23,590 So moving onto fissionable material. 507 00:18:31,300 --> 00:18:34,690 So fissionable material is just material 508 00:18:34,690 --> 00:18:39,040 that is able to undergo fission after the absorption of a more 509 00:18:39,040 --> 00:18:40,367 energetic neutron. 510 00:18:40,367 --> 00:18:41,200 So that's all it is. 511 00:19:12,705 --> 00:19:14,000 So that's all it is. 512 00:19:14,000 --> 00:19:15,770 So an example of fissionable material 513 00:19:15,770 --> 00:19:20,250 that's inside the other reactors at the same time is U238. 514 00:19:20,250 --> 00:19:24,020 So if a U238 absorbs a thermal neutron, 515 00:19:24,020 --> 00:19:25,530 it's not going to do much. 516 00:19:25,530 --> 00:19:28,640 But if it absorbs a neutron of about like, I would say, 517 00:19:28,640 --> 00:19:32,130 like 2 meV, then it's more willing to undergo fission. 518 00:19:32,130 --> 00:19:33,580 Cool? 519 00:19:33,580 --> 00:19:36,580 And finally we have fertile material. 520 00:19:36,580 --> 00:19:39,050 So fertile material is the basis for breeder reactors. 521 00:19:39,050 --> 00:19:43,910 But fertile material is just material that absorbs a neutron 522 00:19:43,910 --> 00:19:47,480 and then is able to become a piece of fissile material. 523 00:20:05,990 --> 00:20:07,870 So for our purposes, the main types 524 00:20:07,870 --> 00:20:13,005 of fertile material we use are U238 and thorium 232. 525 00:20:13,005 --> 00:20:14,380 So if you look at these processes 526 00:20:14,380 --> 00:20:16,510 you can see that U238 absorbs a neutron, 527 00:20:16,510 --> 00:20:19,480 becomes U239, undergoes a beta decay to come neptunium 528 00:20:19,480 --> 00:20:21,670 and undergoes one more beta decay to become 529 00:20:21,670 --> 00:20:24,010 the beautiful plutonium 239. 530 00:20:24,010 --> 00:20:26,170 If we start with thorium 232 instead, 531 00:20:26,170 --> 00:20:28,810 absorbs a neutron, becomes thorium 233, 532 00:20:28,810 --> 00:20:31,330 undergoes a beta decay to become protactinium, 533 00:20:31,330 --> 00:20:34,690 becomes uranium 233, which is another fissile material 534 00:20:34,690 --> 00:20:37,240 by the way, through a series of beta decays. 535 00:20:37,240 --> 00:20:38,430 Cool? 536 00:20:38,430 --> 00:20:40,180 So that's what breeder reactors are doing. 537 00:20:40,180 --> 00:20:42,630 They're adding extra chunks of uranium 238 538 00:20:42,630 --> 00:20:45,970 and extra chunks of thorium 232 into the reactor. 539 00:20:45,970 --> 00:20:48,180 If one of the neutrons-- so imagine-- 540 00:20:48,180 --> 00:20:49,930 if you're looking at the little fuel core, 541 00:20:49,930 --> 00:20:52,013 there's a bunch of neutrons that are flying around 542 00:20:52,013 --> 00:20:54,080 and heat and other isotopes and things like that. 543 00:20:54,080 --> 00:20:56,455 So some of the neutrons will go and create other fissions 544 00:20:56,455 --> 00:20:58,480 with the material that's hanging out in the red. 545 00:20:58,480 --> 00:21:00,307 But other neutrons might escape, and when 546 00:21:00,307 --> 00:21:02,140 they escape, instead of going into the water 547 00:21:02,140 --> 00:21:04,557 dissipating and never to be seen again or being reflected, 548 00:21:04,557 --> 00:21:07,425 they instead create more fissile material. 549 00:21:07,425 --> 00:21:08,800 So you can understand why this is 550 00:21:08,800 --> 00:21:10,870 a kind of an attractive idea, is that you're 551 00:21:10,870 --> 00:21:12,280 creating your own fuel. 552 00:21:12,280 --> 00:21:14,770 You're able to work at a higher fuel efficiency 553 00:21:14,770 --> 00:21:17,500 because you don't need to add in as much fissile materials 554 00:21:17,500 --> 00:21:20,268 as you would for a normal light water reactor. 555 00:21:20,268 --> 00:21:22,810 So people were really fascinated with this idea, like I said, 556 00:21:22,810 --> 00:21:23,650 in the 50s and 60s. 557 00:21:23,650 --> 00:21:25,690 Because back in the day they legitimately 558 00:21:25,690 --> 00:21:27,860 thought that we would run out of U235. 559 00:21:27,860 --> 00:21:29,410 But luckily in the 60s we discovered 560 00:21:29,410 --> 00:21:31,750 that we have a lot more uranium ore than we thought we did. 561 00:21:31,750 --> 00:21:33,810 We're probably not going to run out anytime soon. 562 00:21:33,810 --> 00:21:36,460 And after that discovery, people were not nearly as interested 563 00:21:36,460 --> 00:21:38,050 in breeder reactors. 564 00:21:38,050 --> 00:21:40,930 The reason being is that, one, because there's just 565 00:21:40,930 --> 00:21:42,897 this extra material that's hanging out, 566 00:21:42,897 --> 00:21:44,980 this extra material could be more fissile material 567 00:21:44,980 --> 00:21:46,147 that creates more reactions. 568 00:21:46,147 --> 00:21:50,200 It's not nearly as power efficient. 569 00:21:50,200 --> 00:21:52,773 And it's also slightly more expensive 570 00:21:52,773 --> 00:21:54,940 because you're not being able to be power efficient. 571 00:21:54,940 --> 00:21:58,750 And it also is better on paper than it ever is in reality. 572 00:21:58,750 --> 00:22:00,970 So on paper you're like, oh, this is great, 573 00:22:00,970 --> 00:22:02,470 because I can just create more fissile materials. 574 00:22:02,470 --> 00:22:03,580 I never need to add more. 575 00:22:03,580 --> 00:22:05,040 This is never really truly sustainable. 576 00:22:05,040 --> 00:22:07,332 They always have to keep adding more fissile materials, 577 00:22:07,332 --> 00:22:10,510 because it's not as perfect as they want it to be. 578 00:22:10,510 --> 00:22:12,100 Any questions about these things? 579 00:22:16,870 --> 00:22:17,370 Great. 580 00:22:17,370 --> 00:22:18,185 Cool beans. 581 00:22:18,185 --> 00:22:19,810 And then finally we're going to move on 582 00:22:19,810 --> 00:22:21,090 to generation four reactors. 583 00:22:21,090 --> 00:22:23,850 So generation four reactors are all the new kind of reactors 584 00:22:23,850 --> 00:22:25,390 that people want to build. 585 00:22:25,390 --> 00:22:28,362 So the primary objective for these new designs of reactors-- 586 00:22:28,362 --> 00:22:29,820 like, the ones I just told you guys 587 00:22:29,820 --> 00:22:30,990 about, they're all good and well, 588 00:22:30,990 --> 00:22:32,640 but we want to make them better, right? 589 00:22:32,640 --> 00:22:36,130 We want to make them cleaner and safer and more cost effective. 590 00:22:36,130 --> 00:22:37,950 Keep them robust yet sustainable, 591 00:22:37,950 --> 00:22:40,650 and also make them more resistant to people 592 00:22:40,650 --> 00:22:43,980 being able to divert materials into creating nuclear weapons. 593 00:22:43,980 --> 00:22:44,670 So yeah. 594 00:22:44,670 --> 00:22:46,500 Here are the six kinds of generation 595 00:22:46,500 --> 00:22:48,360 four reactor types that were deemed 596 00:22:48,360 --> 00:22:51,870 to be the most promising. 597 00:22:51,870 --> 00:22:53,430 So there's gas-cooled fast reactors, 598 00:22:53,430 --> 00:22:55,540 lead-cooled fast reactors, molten salt reactors, 599 00:22:55,540 --> 00:22:59,010 sodium-cooled fast reactors, very high temperature gas 600 00:22:59,010 --> 00:23:02,253 reactors, and supercritical water-cooled reactors. 601 00:23:02,253 --> 00:23:03,920 So I'm going to be honest with you guys. 602 00:23:03,920 --> 00:23:05,650 I don't know all that much about these 603 00:23:05,650 --> 00:23:07,733 and I don't want to like spew out information that 604 00:23:07,733 --> 00:23:08,922 might potentially be false. 605 00:23:08,922 --> 00:23:10,380 So if you guys are interested, one, 606 00:23:10,380 --> 00:23:11,755 you can talk to other lab members 607 00:23:11,755 --> 00:23:13,330 or people in this department. 608 00:23:13,330 --> 00:23:15,480 I know they're-- mostly Mike's group, actually. 609 00:23:15,480 --> 00:23:16,938 A lot of people in Mike's group are 610 00:23:16,938 --> 00:23:19,320 working on molten salt reactors so you guys can go 611 00:23:19,320 --> 00:23:21,120 ahead and ask them about that. 612 00:23:21,120 --> 00:23:22,680 Or if you're interested you can read more about them 613 00:23:22,680 --> 00:23:24,210 with this hyperlink that I included over here. 614 00:23:24,210 --> 00:23:25,830 Hopefully he will post the slides online 615 00:23:25,830 --> 00:23:27,413 and you guys just click it and there's 616 00:23:27,413 --> 00:23:30,726 a awesome source all about these different kinds of reactors. 617 00:23:30,726 --> 00:23:31,226 OK? 618 00:23:36,950 --> 00:23:37,450 All right. 619 00:23:37,450 --> 00:23:39,480 Any questions? 620 00:23:39,480 --> 00:23:39,980 Hi. 621 00:23:39,980 --> 00:23:41,688 AUDIENCE: Do any of these actually exist, 622 00:23:41,688 --> 00:23:44,032 or is it all just theory? 623 00:23:44,032 --> 00:23:46,240 TA: I'm pretty sure that they were just kind of proof 624 00:23:46,240 --> 00:23:47,365 of concept stage right now. 625 00:23:47,365 --> 00:23:50,000 Like there aren't any that are producing electricity 626 00:23:50,000 --> 00:23:54,155 in the United States, at least. 627 00:23:54,155 --> 00:23:55,580 Cool. 628 00:23:55,580 --> 00:23:56,750 Good question. 629 00:23:56,750 --> 00:23:58,280 All right. 630 00:23:58,280 --> 00:24:00,920 So all the things that we've mentioned before like how 631 00:24:00,920 --> 00:24:03,260 great nuclear is and all the cool applications of it 632 00:24:03,260 --> 00:24:05,960 and how simple and easy reactors are, 633 00:24:05,960 --> 00:24:07,670 why aren't we using more of it? 634 00:24:07,670 --> 00:24:11,060 So currently in the US there's only 99 operating reactors 635 00:24:11,060 --> 00:24:14,780 that are producing electricity, which makes up about 19% 636 00:24:14,780 --> 00:24:17,300 or about 20% of the total electricity 637 00:24:17,300 --> 00:24:18,890 output in the United States. 638 00:24:18,890 --> 00:24:20,780 The main players are still, you would 639 00:24:20,780 --> 00:24:24,030 imagine, coal and natural gas. 640 00:24:24,030 --> 00:24:27,532 So this is actually even worse in the rest of the world. 641 00:24:27,532 --> 00:24:29,740 In the rest of world, there's only about 440 reactors 642 00:24:29,740 --> 00:24:32,930 spread around 30 countries and produces only 14% 643 00:24:32,930 --> 00:24:34,760 of the global electricity. 644 00:24:34,760 --> 00:24:36,300 So these proportions are pretty low. 645 00:24:36,300 --> 00:24:38,788 And you're wondering, like, why aren't we 646 00:24:38,788 --> 00:24:39,830 using more nuclear power? 647 00:24:39,830 --> 00:24:42,170 What exactly is holding us back? 648 00:24:42,170 --> 00:24:44,840 So it turns out that the main things that are holding us back 649 00:24:44,840 --> 00:24:51,200 is just social, economic, and therefore like government 650 00:24:51,200 --> 00:24:54,260 hesitance to start using nuclear power more often. 651 00:24:54,260 --> 00:24:56,120 So the main reason why we're a little bit 652 00:24:56,120 --> 00:24:57,870 hesitant to start using more nuclear power 653 00:24:57,870 --> 00:24:59,660 is because of safety issues. 654 00:24:59,660 --> 00:25:02,730 So nuclear-- none of us can argue that nuclear is like 100% 655 00:25:02,730 --> 00:25:03,230 safe. 656 00:25:03,230 --> 00:25:05,090 It actually does have some dangers associated 657 00:25:05,090 --> 00:25:07,173 with it, which is why it's so important that we're 658 00:25:07,173 --> 00:25:08,210 doing what we're doing. 659 00:25:08,210 --> 00:25:09,270 But if you guys look at this chart 660 00:25:09,270 --> 00:25:11,900 that I showed you guys in like the first or second slide, 661 00:25:11,900 --> 00:25:15,260 you'll notice that there are these events listed above. 662 00:25:15,260 --> 00:25:17,990 What are these words? 663 00:25:17,990 --> 00:25:20,416 Three Mile Island, Chernobyl, Fukushima, what are they? 664 00:25:20,416 --> 00:25:21,190 AUDIENCE: Nuclear accidents. 665 00:25:21,190 --> 00:25:23,210 TA: Yeah, so they're some of our biggest nuclear accidents 666 00:25:23,210 --> 00:25:24,710 that we've experienced in history. 667 00:25:24,710 --> 00:25:26,720 And you can see that after a nuclear accident 668 00:25:26,720 --> 00:25:28,640 you can see a pretty steep decline 669 00:25:28,640 --> 00:25:30,230 in the amount of nuclear reactors 670 00:25:30,230 --> 00:25:31,520 that are being commissioned. 671 00:25:31,520 --> 00:25:34,700 So this is especially noticeable at Three Mile Island, which 672 00:25:34,700 --> 00:25:38,720 is essentially the first nuclear reactor accident that we all 673 00:25:38,720 --> 00:25:39,490 had to go through. 674 00:25:39,490 --> 00:25:41,240 You can see that, after Three Mile Island, 675 00:25:41,240 --> 00:25:44,642 you can see this massive steep decline 676 00:25:44,642 --> 00:25:46,850 in the amount of nuclear reactors being commissioned. 677 00:25:46,850 --> 00:25:48,058 This is probably causational. 678 00:25:48,058 --> 00:25:49,580 We can pretty much assume that. 679 00:25:49,580 --> 00:25:51,500 And then you can see that Chernobyl-- once 680 00:25:51,500 --> 00:25:53,480 Chernobyl happened, you can see like this also 681 00:25:53,480 --> 00:25:54,740 another massive decline. 682 00:25:54,740 --> 00:25:57,440 And again Fukushima, once again, with the amount 683 00:25:57,440 --> 00:26:00,140 of reactors being commissioned after the accident just 684 00:26:00,140 --> 00:26:02,740 declines dramatically. 685 00:26:02,740 --> 00:26:04,243 So I'm assuming you guys probably 686 00:26:04,243 --> 00:26:06,910 don't know exactly what happened during each of these accidents. 687 00:26:06,910 --> 00:26:08,510 Like you probably know that they exist, 688 00:26:08,510 --> 00:26:09,968 but like what happened during them? 689 00:26:09,968 --> 00:26:11,970 So if you do know, sorry, but if you don't know, 690 00:26:11,970 --> 00:26:13,165 you're about to know. 691 00:26:13,165 --> 00:26:15,040 So Three Mile Island, which is the first one, 692 00:26:15,040 --> 00:26:17,860 it happened in 1979 on March 28. 693 00:26:17,860 --> 00:26:22,390 So Three Mile Island reactor is a PWR located in Pennsylvania. 694 00:26:22,390 --> 00:26:26,200 So during this time it underwent a core meltdown. 695 00:26:26,200 --> 00:26:28,240 The cause of this is just the fact 696 00:26:28,240 --> 00:26:32,020 that there was some kind of mechanical or electrical system 697 00:26:32,020 --> 00:26:33,700 that prevented coolant water from being 698 00:26:33,700 --> 00:26:36,230 pumped into the primary system. 699 00:26:36,230 --> 00:26:39,040 So because there wasn't enough water 700 00:26:39,040 --> 00:26:42,490 coming to cool up the core, the core began to overheat. 701 00:26:42,490 --> 00:26:44,320 So as the temperature of the core rises, 702 00:26:44,320 --> 00:26:45,700 the pressure also rises. 703 00:26:45,700 --> 00:26:47,030 So they notice this and they're like, oh, shoot, 704 00:26:47,030 --> 00:26:47,830 we got to fix that. 705 00:26:47,830 --> 00:26:49,990 So luckily there is like a little emergency valve 706 00:26:49,990 --> 00:26:52,032 that you can see in this animation gets opened up 707 00:26:52,032 --> 00:26:53,270 and pressure gets released. 708 00:26:53,270 --> 00:26:56,073 So that's all good and well, but unfortunately 709 00:26:56,073 --> 00:26:57,490 after the pressure's released, you 710 00:26:57,490 --> 00:26:59,657 should close the valve again and continue operation. 711 00:26:59,657 --> 00:27:01,180 But it became stuck. 712 00:27:01,180 --> 00:27:02,830 So this valve became stuck and they 713 00:27:02,830 --> 00:27:04,288 didn't realize that it became stuck 714 00:27:04,288 --> 00:27:07,000 because their equipment and their instrumentation 715 00:27:07,000 --> 00:27:08,200 wasn't able to detect that. 716 00:27:08,200 --> 00:27:10,918 So they continued to operate again but this valve was open, 717 00:27:10,918 --> 00:27:13,210 so there was actually water that was getting leaked out 718 00:27:13,210 --> 00:27:16,245 of this primary loop. 719 00:27:16,245 --> 00:27:18,008 So because the water was getting leaked, 720 00:27:18,008 --> 00:27:20,300 they noticed that, oh, shoot, the pressure is dropping. 721 00:27:20,300 --> 00:27:22,383 Well, what do you do when the pressure's dropping? 722 00:27:22,383 --> 00:27:24,520 Apparently you have to make sure that there's not 723 00:27:24,520 --> 00:27:26,603 too many vibrations that could damage the reactor, 724 00:27:26,603 --> 00:27:28,600 so they shut off the coolant pumps. 725 00:27:28,600 --> 00:27:31,030 Or they lower the operation of the coolant pumps. 726 00:27:31,030 --> 00:27:34,030 So now there's water leaking out so the core is getting hotter, 727 00:27:34,030 --> 00:27:35,770 but then they also took out the water 728 00:27:35,770 --> 00:27:38,553 that is usually used to cool the reactor core, 729 00:27:38,553 --> 00:27:39,970 so again it's also getting hotter. 730 00:27:39,970 --> 00:27:43,450 So this combination of events led to a core meltdown. 731 00:27:43,450 --> 00:27:45,730 So the core melted down. 732 00:27:45,730 --> 00:27:48,990 That's never a good thing, by the way. 733 00:27:48,990 --> 00:27:49,555 Yeah. 734 00:27:49,555 --> 00:27:52,008 And yeah, so the core melted down, 735 00:27:52,008 --> 00:27:53,800 the reactor wasn't able to operate anymore. 736 00:27:53,800 --> 00:27:55,420 But luckily at Three Mile Island there 737 00:27:55,420 --> 00:27:57,790 was containment that prevented radioactive isotopes 738 00:27:57,790 --> 00:27:59,650 from leaving the system. 739 00:27:59,650 --> 00:28:01,343 So they actually took a brief survey-- 740 00:28:01,343 --> 00:28:02,260 or not a brief survey. 741 00:28:02,260 --> 00:28:03,890 That's probably a long, long experience. 742 00:28:03,890 --> 00:28:05,932 But they realized that the two million people who 743 00:28:05,932 --> 00:28:07,750 are around Three Mile Island at the time, 744 00:28:07,750 --> 00:28:11,950 within like a two mile radius or like maybe a 30 mile radius 745 00:28:11,950 --> 00:28:14,113 or something like that, they realized that they 746 00:28:14,113 --> 00:28:15,280 didn't get much dose at all. 747 00:28:15,280 --> 00:28:17,650 They collected about a total of 1 milligram more dose 748 00:28:17,650 --> 00:28:18,520 than usual. 749 00:28:18,520 --> 00:28:21,190 So to put that in perspective, an x-ray is six milligrams. 750 00:28:21,190 --> 00:28:23,692 So really nothing that happened at Three Mile Island 751 00:28:23,692 --> 00:28:25,150 other than they had to shut it down 752 00:28:25,150 --> 00:28:26,692 and they had to do expensive repairs. 753 00:28:26,692 --> 00:28:27,728 But people weren't hurt. 754 00:28:27,728 --> 00:28:29,020 The environment wasn't damaged. 755 00:28:29,020 --> 00:28:31,060 It wasn't that bad of a situation. 756 00:28:31,060 --> 00:28:33,130 I think the effect was bigger in concept 757 00:28:33,130 --> 00:28:36,130 than it was in actual damage. 758 00:28:36,130 --> 00:28:40,050 Questions about Three Mile Island accident? 759 00:28:40,050 --> 00:28:40,750 All righty. 760 00:28:40,750 --> 00:28:43,250 The next reactor accident, the big kahuna I like to call it, 761 00:28:43,250 --> 00:28:44,260 is Chernobyl. 762 00:28:44,260 --> 00:28:47,750 So on April 25, 1986 an RMBK reactor 763 00:28:47,750 --> 00:28:50,600 that was located in Ukraine exploded. 764 00:28:50,600 --> 00:28:52,885 So what they were doing at Chernobyl 765 00:28:52,885 --> 00:28:54,260 during the time of this explosion 766 00:28:54,260 --> 00:28:56,427 is that they're actually running, ironically enough, 767 00:28:56,427 --> 00:28:57,600 safety tests. 768 00:28:57,600 --> 00:28:59,510 They were running the reactor at low power 769 00:28:59,510 --> 00:29:00,987 to see how it behaves. 770 00:29:00,987 --> 00:29:03,320 So at low power, I don't think they quite realized this, 771 00:29:03,320 --> 00:29:04,940 but the coolant pumps in the reactor 772 00:29:04,940 --> 00:29:07,620 were also powered by the nuclear reactor being generated. 773 00:29:07,620 --> 00:29:09,610 So if they're running this at low power, 774 00:29:09,610 --> 00:29:11,690 their coolant pumps weren't getting enough energy 775 00:29:11,690 --> 00:29:13,850 to properly cool the fuel core. 776 00:29:13,850 --> 00:29:16,250 So that was unfortunate, and they realized 777 00:29:16,250 --> 00:29:17,550 that this is a bad thing. 778 00:29:17,550 --> 00:29:20,878 So the reactor starts to go supercritical. 779 00:29:20,878 --> 00:29:23,420 So when they realize that the reactor was creating a lot more 780 00:29:23,420 --> 00:29:25,515 fissions than it should have been creating, 781 00:29:25,515 --> 00:29:27,140 they decide to insert the control rods. 782 00:29:27,140 --> 00:29:29,640 So thank goodness we have these high absorption control rods 783 00:29:29,640 --> 00:29:31,340 to slow things down, right? 784 00:29:31,340 --> 00:29:33,410 For some reason, I'm not completely sure 785 00:29:33,410 --> 00:29:37,010 why they did this, but RBMKs, they have graphite 786 00:29:37,010 --> 00:29:38,155 tipped control rods. 787 00:29:38,155 --> 00:29:39,530 So as they lower the control rods 788 00:29:39,530 --> 00:29:42,030 into the water, this graphite tip, which doesn't effectively 789 00:29:42,030 --> 00:29:44,540 absorb neutrons, it displaced a little bit too much water 790 00:29:44,540 --> 00:29:46,873 than was necessary, and that caused the first explosion. 791 00:29:46,873 --> 00:29:49,880 So it went super duper critical and caused the first explosion 792 00:29:49,880 --> 00:29:52,880 at Chernobyl. 793 00:29:52,880 --> 00:29:55,415 Then, for some reason like a couple of minutes later, 794 00:29:55,415 --> 00:29:56,540 there's a second explosion. 795 00:29:56,540 --> 00:29:59,000 They're not completely sure why the second explosion happened. 796 00:29:59,000 --> 00:30:00,708 To this day we can't really pinpoint why. 797 00:30:00,708 --> 00:30:03,470 It could have been like building up helium or just 798 00:30:03,470 --> 00:30:04,845 a ton of other fission reactions. 799 00:30:04,845 --> 00:30:06,887 But there's a second explosion that actually just 800 00:30:06,887 --> 00:30:08,090 blew this entire core apart. 801 00:30:08,090 --> 00:30:12,740 So that kind of stunk, but it did stop the whole reaction. 802 00:30:12,740 --> 00:30:15,127 Because a super critical mass was all blown apart, 803 00:30:15,127 --> 00:30:16,460 it was no longer super critical. 804 00:30:16,460 --> 00:30:17,230 It was fine. 805 00:30:17,230 --> 00:30:18,980 The whole debacle stopped. 806 00:30:18,980 --> 00:30:20,720 But unfortunately, there was a lot 807 00:30:20,720 --> 00:30:24,320 of radioactive isotopes being spread into the environment. 808 00:30:24,320 --> 00:30:26,362 First of all, Chernobyl didn't have the same kind 809 00:30:26,362 --> 00:30:28,112 of containment that Three Mile Island had, 810 00:30:28,112 --> 00:30:30,320 so these isotopes were just able to go everywhere. 811 00:30:30,320 --> 00:30:32,330 And also the second explosion had a lot of steam 812 00:30:32,330 --> 00:30:34,747 with it that carried these isotopes even further than they 813 00:30:34,747 --> 00:30:35,983 probably should have gone. 814 00:30:35,983 --> 00:30:38,150 So if you're looking at the statistics of Chernobyl, 815 00:30:38,150 --> 00:30:39,950 it turned out that 28 highly exposed 816 00:30:39,950 --> 00:30:42,830 reactor staff and emergency workers die from this radiation 817 00:30:42,830 --> 00:30:44,930 or from thermal burns during this time. 818 00:30:44,930 --> 00:30:46,500 And officials also believe that there 819 00:30:46,500 --> 00:30:49,910 is about 7,000 cases of thyroid cancer that occurred 820 00:30:49,910 --> 00:30:51,050 because of Chernobyl. 821 00:30:51,050 --> 00:30:52,430 They're pretty sure it was Chernobyl because these 822 00:30:52,430 --> 00:30:54,230 are all cases that happened in people 823 00:30:54,230 --> 00:30:56,690 who are less than 18 years old. 824 00:30:56,690 --> 00:30:59,150 So you guys know that no one really lives near Chernobyl 825 00:30:59,150 --> 00:30:59,930 at the moment. 826 00:30:59,930 --> 00:31:01,400 It's kind of been deemed unlivable 827 00:31:01,400 --> 00:31:03,350 because these radioactive isotopes literally went 828 00:31:03,350 --> 00:31:04,310 everywhere in this environment. 829 00:31:04,310 --> 00:31:06,380 Like it was in the water, it was in the plants. 830 00:31:06,380 --> 00:31:07,280 It's not safe to live there. 831 00:31:07,280 --> 00:31:08,720 It's a pretty radioactive environment. 832 00:31:08,720 --> 00:31:11,030 Luckily we see that there are animals coming back now now. 833 00:31:11,030 --> 00:31:12,620 If you look on NationalGeographic.com 834 00:31:12,620 --> 00:31:15,140 there's like little deer roaming around Chernobyl. 835 00:31:15,140 --> 00:31:18,260 But it's been about-- how long has it been, like 30, 40 years? 836 00:31:18,260 --> 00:31:21,280 People aren't advised to live here still. 837 00:31:21,280 --> 00:31:23,690 So Chernobyl was terrible. 838 00:31:23,690 --> 00:31:25,590 Questions? 839 00:31:25,590 --> 00:31:26,757 Yeah? 840 00:31:26,757 --> 00:31:29,340 AUDIENCE: What does it mean for a reactor to go supercritical? 841 00:31:29,340 --> 00:31:30,173 TA: Oh, yeah, sorry. 842 00:31:30,173 --> 00:31:33,107 So you guys will learn all about criticality in a little bit, 843 00:31:33,107 --> 00:31:34,690 but basically when I say supercritical 844 00:31:34,690 --> 00:31:36,648 it just means that there's way too many fission 845 00:31:36,648 --> 00:31:39,184 reactions happening. 846 00:31:39,184 --> 00:31:40,975 Yeah? 847 00:31:40,975 --> 00:31:43,100 AUDIENCE: You said it went supercritical because it 848 00:31:43,100 --> 00:31:44,990 wasn't being cooled enough or? 849 00:31:44,990 --> 00:31:46,740 TA: I think I might have skipped a detail. 850 00:31:46,740 --> 00:31:48,500 It wasn't being cooled enough so the water was evaporating 851 00:31:48,500 --> 00:31:50,000 and then it became supercritical because there was not 852 00:31:50,000 --> 00:31:52,150 enough neutrons being slowed down or absorbed. 853 00:31:52,150 --> 00:31:53,120 My bad, I'm sorry. 854 00:31:55,640 --> 00:31:56,530 Good? 855 00:31:56,530 --> 00:31:57,380 All right. 856 00:31:57,380 --> 00:32:00,380 So the next reactor accident that we were alive for, 857 00:32:00,380 --> 00:32:03,380 which is cool, was Fukushima Daiichi. 858 00:32:03,380 --> 00:32:06,390 So Fukushima Daiichi happened in 2011 on March 11, 859 00:32:06,390 --> 00:32:10,920 and Fukushima is in Japan. 860 00:32:10,920 --> 00:32:15,080 So these reactors, I think these are pressurized water reactors. 861 00:32:15,080 --> 00:32:16,090 Yeah, I think so. 862 00:32:16,090 --> 00:32:20,210 So following a major earthquake, the generators that were-- 863 00:32:20,210 --> 00:32:21,310 pardon. 864 00:32:21,310 --> 00:32:23,660 Yeah, so following a major earthquake, 865 00:32:23,660 --> 00:32:27,200 the things that were cooling the core, they broke. 866 00:32:27,200 --> 00:32:29,840 I think they're just like power generators on the side that 867 00:32:29,840 --> 00:32:31,200 did-- 868 00:32:31,200 --> 00:32:31,700 yeah. 869 00:32:31,700 --> 00:32:32,480 They broke the cooling pumps. 870 00:32:32,480 --> 00:32:33,980 So there wasn't enough water being 871 00:32:33,980 --> 00:32:35,327 able to go to the fuel core. 872 00:32:35,327 --> 00:32:36,910 This is a very similar problem, as you 873 00:32:36,910 --> 00:32:39,055 can see that in all these instances of the reactor 874 00:32:39,055 --> 00:32:41,180 incidents, it's just kind of like the fuel core was 875 00:32:41,180 --> 00:32:43,010 misbehaving and we weren't able to get 876 00:32:43,010 --> 00:32:44,510 enough coolant water to it. 877 00:32:44,510 --> 00:32:47,010 So following the earthquake, these coolant pumps broke. 878 00:32:47,010 --> 00:32:48,238 They're like, oh, that's OK. 879 00:32:48,238 --> 00:32:50,030 What we can do is we have backup generators 880 00:32:50,030 --> 00:32:51,280 to continue running the pumps. 881 00:32:51,280 --> 00:32:52,700 It'll be all OK. 882 00:32:52,700 --> 00:32:53,965 Nothing will happen. 883 00:32:53,965 --> 00:32:54,590 We're all good. 884 00:32:54,590 --> 00:32:55,640 And then a tsunami hit. 885 00:32:55,640 --> 00:32:57,290 So it was a foot tsunami I think-- 886 00:32:57,290 --> 00:32:57,920 I think that-- 887 00:32:57,920 --> 00:33:00,010 15 meter tsunami, oh good gosh. 888 00:33:00,010 --> 00:33:02,360 So a 15 meter tsunami hit and it broke 889 00:33:02,360 --> 00:33:06,050 the generators and then at that point they're like, oh, no. 890 00:33:06,050 --> 00:33:08,090 So they had no other redundancy factors 891 00:33:08,090 --> 00:33:10,340 to continue pumping cool water into the fuel core. 892 00:33:10,340 --> 00:33:11,798 So again, there wasn't enough water 893 00:33:11,798 --> 00:33:13,360 in the core, it became supercritical, 894 00:33:13,360 --> 00:33:17,090 it began to melt. So the fuel rods began to melt, 895 00:33:17,090 --> 00:33:19,470 but this is actually another additional bad thing. 896 00:33:19,470 --> 00:33:22,610 So the water was evaporating, creating steam. 897 00:33:22,610 --> 00:33:24,440 The fuel rods were coated with zirconium. 898 00:33:24,440 --> 00:33:26,180 So what you guys might not know is 899 00:33:26,180 --> 00:33:28,880 that when zirconium and steam interact with each other, 900 00:33:28,880 --> 00:33:30,090 that's not a good thing. 901 00:33:30,090 --> 00:33:32,790 It starts to explode. 902 00:33:32,790 --> 00:33:37,280 So as you can see, the reactors at Fukushima Daiichi 903 00:33:37,280 --> 00:33:38,450 began to explode. 904 00:33:38,450 --> 00:33:41,918 There was radioactive isotopes being spread out all 905 00:33:41,918 --> 00:33:42,710 around the country. 906 00:33:42,710 --> 00:33:44,030 You guys probably saw the lovely flow charts 907 00:33:44,030 --> 00:33:45,950 of the radioactivity flowing out from Japan 908 00:33:45,950 --> 00:33:47,630 and making it to California and contaminating your fish 909 00:33:47,630 --> 00:33:48,620 and stuff like that. 910 00:33:48,620 --> 00:33:52,500 But luckily, no one was directly hurt by burns or radioactive 911 00:33:52,500 --> 00:33:53,000 exposure. 912 00:33:53,000 --> 00:33:54,230 Cool? 913 00:33:54,230 --> 00:33:55,090 All right. 914 00:33:55,090 --> 00:33:56,467 Questions about Fukushima? 915 00:33:59,790 --> 00:34:00,290 Solid. 916 00:34:00,290 --> 00:34:02,050 So aside from these safety issues, 917 00:34:02,050 --> 00:34:06,130 these safety issues that happen, they get elevated in the news 918 00:34:06,130 --> 00:34:06,761 quite a lot. 919 00:34:06,761 --> 00:34:09,219 So these are mainly the things that people who don't really 920 00:34:09,219 --> 00:34:10,750 have any background in nuclear energy 921 00:34:10,750 --> 00:34:11,650 hear about nuclear energy. 922 00:34:11,650 --> 00:34:13,275 They're like, oh shoot, well this thing 923 00:34:13,275 --> 00:34:14,900 is going to explode every 20 years. 924 00:34:14,900 --> 00:34:16,458 Like, why do we keep using this? 925 00:34:16,458 --> 00:34:18,250 Reactor accidents are actually pretty rare. 926 00:34:18,250 --> 00:34:21,520 If you think about it, it's been about 60 or 70 years, 927 00:34:21,520 --> 00:34:24,219 we have 440 reactors operating around the country. 928 00:34:24,219 --> 00:34:26,219 There's three main accidents that have happened. 929 00:34:26,219 --> 00:34:28,636 But because these are the things that people get ingrained 930 00:34:28,636 --> 00:34:30,610 into their mind-- thank you, news stations-- 931 00:34:30,610 --> 00:34:32,350 people think that nuclear reactors 932 00:34:32,350 --> 00:34:33,719 are incredibly dangerous. 933 00:34:33,719 --> 00:34:35,920 And that's why we have this social hesitance, which 934 00:34:35,920 --> 00:34:38,250 is why we aren't able to get enough government funding 935 00:34:38,250 --> 00:34:39,880 and which is why there's all these bureaucracy 936 00:34:39,880 --> 00:34:41,830 loopholes to jump through, which is why nuclear power isn't 937 00:34:41,830 --> 00:34:42,900 more of a thing. 938 00:34:42,900 --> 00:34:43,480 Makes sense? 939 00:34:43,480 --> 00:34:45,027 Yeah. 940 00:34:45,027 --> 00:34:47,110 Another issue that's associated with nuclear power 941 00:34:47,110 --> 00:34:48,429 is nuclear waste. 942 00:34:48,429 --> 00:34:50,409 So what in the world do we do with it? 943 00:34:50,409 --> 00:34:54,100 So first of all, the main thing in nuclear waste is spent fuel. 944 00:34:54,100 --> 00:34:56,440 So like I mentioned to you guys, spent fuel rods 945 00:34:56,440 --> 00:34:57,750 are made out of uranium oxide. 946 00:34:57,750 --> 00:34:59,458 But after undergoing a bunch of fissions, 947 00:34:59,458 --> 00:35:02,380 these uranium particles get transformed into other isotopes 948 00:35:02,380 --> 00:35:05,980 that aren't fissionable or fertile or even remotely 949 00:35:05,980 --> 00:35:07,810 fissile, right? 950 00:35:07,810 --> 00:35:10,300 So we eventually have to replace them and add in new rods, 951 00:35:10,300 --> 00:35:13,080 and this is a process that happens every 12 or so years. 952 00:35:13,080 --> 00:35:14,830 I'm not completely sure on that statistic. 953 00:35:14,830 --> 00:35:16,690 But the main issue's like, what do we 954 00:35:16,690 --> 00:35:18,700 do with all this material? 955 00:35:18,700 --> 00:35:21,220 So this material that comes out is pretty radioactive 956 00:35:21,220 --> 00:35:23,110 and it's also incredibly hot, so it 957 00:35:23,110 --> 00:35:25,710 can be dangerous if someone decides to come and eat it. 958 00:35:25,710 --> 00:35:29,630 So that's why we've got to figure out a way to expose it. 959 00:35:29,630 --> 00:35:32,260 So the primary way of disposing of the spent fuel 960 00:35:32,260 --> 00:35:34,330 is putting it into spent fuel pools. 961 00:35:34,330 --> 00:35:36,850 So spent fuel pools are just giant tanks of water 962 00:35:36,850 --> 00:35:38,380 that exist at the reactor. 963 00:35:38,380 --> 00:35:39,850 So these tanks of water are mixed 964 00:35:39,850 --> 00:35:42,707 with I believe it's boron, which is a neutron absorber. 965 00:35:42,707 --> 00:35:44,290 They basically just put the spent fuel 966 00:35:44,290 --> 00:35:46,082 rods all the way at the bottom of the pool. 967 00:35:46,082 --> 00:35:48,170 So this pool's about like 20 meters high, I think. 968 00:35:48,170 --> 00:35:49,330 This is actually a really good solution 969 00:35:49,330 --> 00:35:52,290 because the water in the pool, it cools down the reactor rods 970 00:35:52,290 --> 00:35:54,010 and also prevents a lot of neutrons 971 00:35:54,010 --> 00:35:56,712 from escaping because water is a really great neutron moderator. 972 00:35:56,712 --> 00:35:57,670 You guys all know this. 973 00:35:57,670 --> 00:36:00,427 It turns out it's actually fairly safe. 974 00:36:00,427 --> 00:36:03,010 Apparently you can go swimming on the top of the reactor spent 975 00:36:03,010 --> 00:36:05,200 fuel pool and you'll be OK and not 976 00:36:05,200 --> 00:36:08,330 be exposed to too much radiation if you want. 977 00:36:08,330 --> 00:36:09,413 So yeah. 978 00:36:09,413 --> 00:36:11,080 So this is the main solution that people 979 00:36:11,080 --> 00:36:12,538 have been using for years, but they 980 00:36:12,538 --> 00:36:14,410 realize that this isn't super sustainable, 981 00:36:14,410 --> 00:36:16,702 because the amount of space that we have in these spent 982 00:36:16,702 --> 00:36:18,140 fuel pools is not infinite. 983 00:36:18,140 --> 00:36:20,070 We have way too much spent fuel to be 984 00:36:20,070 --> 00:36:22,570 able to just continue to store it in these spent fuel pools. 985 00:36:22,570 --> 00:36:24,403 So like shoot, got to find another solution. 986 00:36:24,403 --> 00:36:25,820 So the next solution was something 987 00:36:25,820 --> 00:36:26,990 called dry cask storage. 988 00:36:26,990 --> 00:36:28,840 So dry cask storage is just a way 989 00:36:28,840 --> 00:36:33,080 to keep this spent fuel surrounded by an inert gas. 990 00:36:33,080 --> 00:36:36,130 And it's held inside a cask, a cask just being probably 991 00:36:36,130 --> 00:36:38,260 like a steel drum that's bolted and welded 992 00:36:38,260 --> 00:36:40,600 shut, and then there's additional pieces 993 00:36:40,600 --> 00:36:43,400 of shielding around it like cement and lead, et cetera. 994 00:36:43,400 --> 00:36:46,330 So there's just like gigantic tanks 995 00:36:46,330 --> 00:36:48,130 basically that are sitting outside. 996 00:36:48,130 --> 00:36:49,290 So they put them outside the reactor. 997 00:36:49,290 --> 00:36:50,707 As you can see, it looks like it's 998 00:36:50,707 --> 00:36:53,400 sitting in a parking lot outside the reactor. 999 00:36:53,400 --> 00:36:55,120 And so this is an OK solution. 1000 00:36:55,120 --> 00:36:57,730 So basically what they do is they take a spent fuel, 1001 00:36:57,730 --> 00:37:00,700 let it sit in the pool for about a year or so, 1002 00:37:00,700 --> 00:37:01,742 maybe two or three years. 1003 00:37:01,742 --> 00:37:04,158 And then they're able to take it out because at that point 1004 00:37:04,158 --> 00:37:06,610 it's significantly less radioactive because, you know, 1005 00:37:06,610 --> 00:37:07,750 you guys know how to calculate this, too. 1006 00:37:07,750 --> 00:37:10,250 You guys know like the half life of different radioisotopes. 1007 00:37:10,250 --> 00:37:12,730 You see that the radioactivity declines at a certain point. 1008 00:37:12,730 --> 00:37:15,063 It's also more cool now so they put them in these tanks, 1009 00:37:15,063 --> 00:37:17,110 so they let these tanks hang out outside. 1010 00:37:17,110 --> 00:37:18,700 And this is an OK solution, except for the fact 1011 00:37:18,700 --> 00:37:20,742 that, again, we just have way too much spent fuel 1012 00:37:20,742 --> 00:37:21,659 to be able to do this. 1013 00:37:21,659 --> 00:37:24,200 It turns out that if you were to just keep all the spent fuel 1014 00:37:24,200 --> 00:37:25,940 that we create in fuel casks, it'd 1015 00:37:25,940 --> 00:37:28,600 take about 300 acres of land, which is absolutely insane. 1016 00:37:28,600 --> 00:37:32,578 And obviously no one wants to take up that. 1017 00:37:32,578 --> 00:37:34,870 Brief little side note, when I was googling like images 1018 00:37:34,870 --> 00:37:36,190 of dry cask storage and I was looking 1019 00:37:36,190 --> 00:37:38,020 for the different types, what I found particularly 1020 00:37:38,020 --> 00:37:39,700 disturbing was that there's only two types listed: 1021 00:37:39,700 --> 00:37:41,320 vertical storage and horizontal storage. 1022 00:37:41,320 --> 00:37:42,670 Like there's no other solutions other 1023 00:37:42,670 --> 00:37:43,900 than these are giant tanks. 1024 00:37:43,900 --> 00:37:46,000 Anyway, so people realize that we 1025 00:37:46,000 --> 00:37:47,620 need to figure out yet another way 1026 00:37:47,620 --> 00:37:49,540 to dispose of the spent fuel, hopefully 1027 00:37:49,540 --> 00:37:52,420 a way that doesn't get in the way of people's backyards. 1028 00:37:52,420 --> 00:37:56,270 So the idea was something called deep geological repositories. 1029 00:37:56,270 --> 00:37:58,600 So deep geologic repositories literally just 1030 00:37:58,600 --> 00:38:00,400 means that they want to bury the nuclear waste very deep 1031 00:38:00,400 --> 00:38:02,692 into the ground and never be able to retrieve it again. 1032 00:38:02,692 --> 00:38:04,847 So the main push for this was-- 1033 00:38:04,847 --> 00:38:07,180 well, first of all, it's a permanent method of disposal. 1034 00:38:07,180 --> 00:38:08,830 They hope to put it in the ground 1035 00:38:08,830 --> 00:38:09,940 and never have to think about it again, 1036 00:38:09,940 --> 00:38:11,530 so therefore the regions that they 1037 00:38:11,530 --> 00:38:13,300 choose to bury in the ground have 1038 00:38:13,300 --> 00:38:15,520 to fulfill a lot of criteria. 1039 00:38:15,520 --> 00:38:17,947 So this criterion includes not having 1040 00:38:17,947 --> 00:38:19,030 a lot of seismic activity. 1041 00:38:19,030 --> 00:38:21,670 Because we are keeping this nuclear waste underground 1042 00:38:21,670 --> 00:38:23,650 in these casks for like thousands of years, 1043 00:38:23,650 --> 00:38:25,870 if there is a huge earthquake, those casks break, 1044 00:38:25,870 --> 00:38:27,020 radiation gets everywhere. 1045 00:38:27,020 --> 00:38:28,190 That's obviously not a good thing 1046 00:38:28,190 --> 00:38:29,380 so we want to make sure that doesn't happen. 1047 00:38:29,380 --> 00:38:30,580 We also have to make sure that there's not 1048 00:38:30,580 --> 00:38:32,140 a lot of water that leaks through, 1049 00:38:32,140 --> 00:38:35,518 because the water can carry the radioisotopes 1050 00:38:35,518 --> 00:38:37,810 and carry them into the environment, which is something 1051 00:38:37,810 --> 00:38:39,418 else that we don't want to do. 1052 00:38:39,418 --> 00:38:41,710 A lot of you guys chuckled when you saw Yucca Mountain. 1053 00:38:41,710 --> 00:38:45,400 So Yucca Mountain is the primary push by the United States 1054 00:38:45,400 --> 00:38:47,867 to find a deep geological repository somewhere 1055 00:38:47,867 --> 00:38:50,200 in the United States so we can deal with our spent fuel. 1056 00:38:50,200 --> 00:38:52,720 So in 2002 the main push for this began. 1057 00:38:52,720 --> 00:38:54,070 They spent a lot of money. 1058 00:38:54,070 --> 00:38:55,528 They spent like billions of dollars 1059 00:38:55,528 --> 00:38:57,957 finding the perfect location to put our spent fuel. 1060 00:38:57,957 --> 00:38:59,540 They had like nine different locations 1061 00:38:59,540 --> 00:39:00,680 and they finally narrowed it down to Yucca Mountain. 1062 00:39:00,680 --> 00:39:02,200 They're like, yes, this is the one, 1063 00:39:02,200 --> 00:39:05,450 and they started digging down deep into Yucca Mountain 1064 00:39:05,450 --> 00:39:07,610 and making this happen. 1065 00:39:07,610 --> 00:39:09,560 But then things weren't as peachy keen 1066 00:39:09,560 --> 00:39:11,150 as they hoped it would be. 1067 00:39:11,150 --> 00:39:13,340 So Yucca Mountain is located in Nevada. 1068 00:39:13,340 --> 00:39:15,300 People in Nevada weren't happy about this. 1069 00:39:15,300 --> 00:39:18,113 They're like, why are we getting tossed on nuclear waste? 1070 00:39:18,113 --> 00:39:20,030 We don't even have nuclear reactors in Nevada. 1071 00:39:20,030 --> 00:39:21,320 This is not fair. 1072 00:39:21,320 --> 00:39:22,940 There was a lot of opposition. 1073 00:39:22,940 --> 00:39:24,440 And because of the social opposition 1074 00:39:24,440 --> 00:39:26,790 there was government opposition and many loopholes 1075 00:39:26,790 --> 00:39:28,540 we had to jump through, and so it was just 1076 00:39:28,540 --> 00:39:29,720 becoming a huge disaster. 1077 00:39:29,720 --> 00:39:31,430 They also realized that it wasn't as geologically 1078 00:39:31,430 --> 00:39:32,270 sound as they had hoped. 1079 00:39:32,270 --> 00:39:34,250 There's a lot more groundwater running through and seeping 1080 00:39:34,250 --> 00:39:36,650 through Yucca Mountain than they thought there would be, 1081 00:39:36,650 --> 00:39:40,170 so it's actually not as safe as they had hoped. 1082 00:39:40,170 --> 00:39:41,510 So there's a huge debacle. 1083 00:39:41,510 --> 00:39:43,490 Basically the costs are rising, nothing much was happening, 1084 00:39:43,490 --> 00:39:45,740 there's a bunch of different things preventing progression 1085 00:39:45,740 --> 00:39:46,490 from happening. 1086 00:39:46,490 --> 00:39:48,610 And then 2011, under the Obama Administration, 1087 00:39:48,610 --> 00:39:49,610 he just called it quits. 1088 00:39:49,610 --> 00:39:51,380 There's no more government funding to Yucca Mountain. 1089 00:39:51,380 --> 00:39:54,170 It's been abandoned, as you can see from this lovely Google 1090 00:39:54,170 --> 00:39:54,950 picture. 1091 00:39:54,950 --> 00:39:56,210 It's permanently closed. 1092 00:39:56,210 --> 00:39:58,793 And you can also see that like 14 people went out of their way 1093 00:39:58,793 --> 00:40:00,023 to review Yucca Mountain. 1094 00:40:00,023 --> 00:40:01,190 But we're actually doing OK. 1095 00:40:01,190 --> 00:40:04,100 It's at like 3.6 stars, just like a normal motel 1096 00:40:04,100 --> 00:40:07,510 or something like that, so that has been abandoned. 1097 00:40:07,510 --> 00:40:10,010 This idea has currently been abandoned in the United States. 1098 00:40:10,010 --> 00:40:12,200 We're kind of still looking for other solutions, 1099 00:40:12,200 --> 00:40:15,140 but we really don't have it figured out all that well. 1100 00:40:15,140 --> 00:40:18,200 There is one other kind of way of dealing with nuclear waste, 1101 00:40:18,200 --> 00:40:19,220 which is repurposing. 1102 00:40:19,220 --> 00:40:20,928 I personally think nuclear repurposing is 1103 00:40:20,928 --> 00:40:22,310 the coolest option out there. 1104 00:40:22,310 --> 00:40:23,810 And basically repurposing just means 1105 00:40:23,810 --> 00:40:25,560 you take the spent fuel and you chemically 1106 00:40:25,560 --> 00:40:28,753 separate out any material that could be continued to be used-- 1107 00:40:28,753 --> 00:40:30,170 any fissile material that could be 1108 00:40:30,170 --> 00:40:31,820 continued to be used in other reactors. 1109 00:40:31,820 --> 00:40:34,700 So basically you take the spent fuel-- 1110 00:40:34,700 --> 00:40:36,820 and it turns out that 96% of a used fuel assembly 1111 00:40:36,820 --> 00:40:37,460 is recyclable. 1112 00:40:37,460 --> 00:40:38,840 So you take the spent fuel, you take out 1113 00:40:38,840 --> 00:40:40,620 what it is useful, you throw away what's not useful, 1114 00:40:40,620 --> 00:40:42,170 which is also still radioactive waste that 1115 00:40:42,170 --> 00:40:44,337 has to be put in a fuel pool or something like that. 1116 00:40:44,337 --> 00:40:46,460 But you have this precious fuel that you 1117 00:40:46,460 --> 00:40:48,470 can put into another reactor. 1118 00:40:48,470 --> 00:40:50,568 So this is actually something that France 1119 00:40:50,568 --> 00:40:52,610 and other places in Europe, and Russia and Japan, 1120 00:40:52,610 --> 00:40:56,480 they use repurposing quite a lot. 1121 00:40:56,480 --> 00:40:58,610 For some reason the United States doesn't do it. 1122 00:40:58,610 --> 00:41:01,087 So the reason being is that this is a really cool idea. 1123 00:41:01,087 --> 00:41:01,920 It's like recycling. 1124 00:41:01,920 --> 00:41:04,077 It's like very-- it's very clever. 1125 00:41:04,077 --> 00:41:06,660 I think I think it's personally one of the cleverer solutions, 1126 00:41:06,660 --> 00:41:10,520 but the issue is that it's kind of a really expensive process. 1127 00:41:10,520 --> 00:41:13,218 So repurposing fuel takes a lot of money 1128 00:41:13,218 --> 00:41:15,260 and it turns out that the act of repurposing fuel 1129 00:41:15,260 --> 00:41:16,790 actually costs more than just buying 1130 00:41:16,790 --> 00:41:19,620 a new chunk of uranium 235, which is why we don't do it. 1131 00:41:19,620 --> 00:41:21,600 It's not economically sound. 1132 00:41:21,600 --> 00:41:22,400 So yeah. 1133 00:41:22,400 --> 00:41:24,150 You guys have any questions about anything 1134 00:41:24,150 --> 00:41:28,010 I've mentioned, about deposition of nuclear waste? 1135 00:41:28,010 --> 00:41:28,510 Almost done. 1136 00:41:28,510 --> 00:41:30,290 OK. 1137 00:41:30,290 --> 00:41:31,880 So all these are issues. 1138 00:41:31,880 --> 00:41:33,963 Like, we have a lot of nuclear waste to deal with. 1139 00:41:33,963 --> 00:41:34,880 It is kind of-- 1140 00:41:34,880 --> 00:41:37,328 there is an inherent danger with using nuclear power. 1141 00:41:37,328 --> 00:41:38,870 But the real thing that holds us back 1142 00:41:38,870 --> 00:41:40,880 from just having nuclear power everywhere 1143 00:41:40,880 --> 00:41:43,550 and creating about 90% of our electricity 1144 00:41:43,550 --> 00:41:46,470 as we would hope it would is economics. 1145 00:41:46,470 --> 00:41:49,700 So in this world, money really matters a lot. 1146 00:41:49,700 --> 00:41:51,575 The economics of nuclear power is actually 1147 00:41:51,575 --> 00:41:54,470 a really complicated topic and it changes 1148 00:41:54,470 --> 00:41:55,730 depending on who you talk to. 1149 00:41:55,730 --> 00:41:56,990 There's a lot of factors that are involved, 1150 00:41:56,990 --> 00:41:58,430 so you can include certain factors 1151 00:41:58,430 --> 00:42:00,740 into your calculations like, oh, the cost 1152 00:42:00,740 --> 00:42:02,738 of building the reactor in the first place 1153 00:42:02,738 --> 00:42:04,280 or like fuel costs or operating costs 1154 00:42:04,280 --> 00:42:06,697 or maintenance costs or the amount of money that comes out 1155 00:42:06,697 --> 00:42:08,000 of damaging the environment. 1156 00:42:08,000 --> 00:42:09,650 You can weigh all these different factors in, 1157 00:42:09,650 --> 00:42:11,470 and everyone churns out a different number. 1158 00:42:11,470 --> 00:42:14,053 But basically everyone you talk to, if you look at this chart, 1159 00:42:14,053 --> 00:42:17,510 yellow is nuclear power, the gray is coal, 1160 00:42:17,510 --> 00:42:18,973 and the blue is the natural gas. 1161 00:42:18,973 --> 00:42:20,390 But basically, anyone you talk to, 1162 00:42:20,390 --> 00:42:22,160 you can see that nuclear is not nearly as 1163 00:42:22,160 --> 00:42:25,520 economic of a source of electricity generation 1164 00:42:25,520 --> 00:42:28,505 as any other of these ones I mentioned. 1165 00:42:28,505 --> 00:42:29,630 Unless you talk to UK. 1166 00:42:29,630 --> 00:42:31,160 UK thinks it's OK. 1167 00:42:31,160 --> 00:42:35,030 But everyone else is saying that it's not as money efficient. 1168 00:42:35,030 --> 00:42:37,548 So where are all these costs coming from? 1169 00:42:37,548 --> 00:42:39,590 So the primary costs actually lies with something 1170 00:42:39,590 --> 00:42:40,465 called capital costs. 1171 00:42:40,465 --> 00:42:42,230 So capital cost is basically the sunk cost 1172 00:42:42,230 --> 00:42:43,790 of just building the reactor. 1173 00:42:43,790 --> 00:42:45,890 Building reactors takes billions of dollars. 1174 00:42:45,890 --> 00:42:47,015 It also takes tons of time. 1175 00:42:47,015 --> 00:42:48,473 And because it takes a lot of time, 1176 00:42:48,473 --> 00:42:50,660 interest rates also jack up that price even further. 1177 00:42:50,660 --> 00:42:52,880 So basically it's just this massive investment 1178 00:42:52,880 --> 00:42:55,150 they have to throw in immediately, 1179 00:42:55,150 --> 00:42:56,900 and this is where most of the issues lie. 1180 00:42:56,900 --> 00:42:59,722 Like it's really hard to go to an investor and be like, hey, 1181 00:42:59,722 --> 00:43:02,180 can I have a billion dollars to build this nuclear reactor? 1182 00:43:02,180 --> 00:43:03,350 It's going to take five years and it's 1183 00:43:03,350 --> 00:43:05,910 going to take 20 more years for you to get your profit back. 1184 00:43:05,910 --> 00:43:06,980 How does that sound? 1185 00:43:06,980 --> 00:43:09,560 No investor is going to be like, yeah, that's a good idea. 1186 00:43:09,560 --> 00:43:10,640 That's the main reason why we can't 1187 00:43:10,640 --> 00:43:11,450 get nuclear up and running. 1188 00:43:11,450 --> 00:43:12,980 We have a lot of plants and we have the possibility 1189 00:43:12,980 --> 00:43:14,030 to create a lot of plants, but we just 1190 00:43:14,030 --> 00:43:15,560 don't have the money to do so. 1191 00:43:15,560 --> 00:43:19,190 Because it's a huge chunk of money, like I mentioned before, 1192 00:43:19,190 --> 00:43:20,930 it takes a while to get your profit back. 1193 00:43:20,930 --> 00:43:23,415 And also, if for some reason something happens, 1194 00:43:23,415 --> 00:43:25,040 you have to stop building your reactor. 1195 00:43:25,040 --> 00:43:26,373 You just lost a billion dollars. 1196 00:43:26,373 --> 00:43:27,970 Like, there's no turning back, right? 1197 00:43:27,970 --> 00:43:29,720 If you look at this chart over here, which 1198 00:43:29,720 --> 00:43:31,700 is breaking up the cost of nuclear energy 1199 00:43:31,700 --> 00:43:32,960 per kilowatt hour, I believe-- 1200 00:43:32,960 --> 00:43:33,710 gigawatt hour? 1201 00:43:33,710 --> 00:43:34,430 Kilowatt hour. 1202 00:43:34,430 --> 00:43:35,180 Kilowatt hour. 1203 00:43:35,180 --> 00:43:37,350 You can see nuclear, coal, and natural gas. 1204 00:43:37,350 --> 00:43:39,475 So this giant white chunk over here refers to fuel. 1205 00:43:39,475 --> 00:43:41,850 So if you can look at nuclear power, the majority of cost 1206 00:43:41,850 --> 00:43:44,210 actually doesn't come from nuclear fuel at all. 1207 00:43:44,210 --> 00:43:46,880 It's just about $0.01 per kilowatt hour, 1208 00:43:46,880 --> 00:43:49,040 as compared to natural gas, which 1209 00:43:49,040 --> 00:43:50,720 the majority of the costs of electricity 1210 00:43:50,720 --> 00:43:51,920 actually come from the fuel. 1211 00:43:51,920 --> 00:43:53,270 If you look at operation and maintenance, 1212 00:43:53,270 --> 00:43:54,390 again it's not that large of a chunk. 1213 00:43:54,390 --> 00:43:56,750 It's about the same as maintaining a coal power plant. 1214 00:43:56,750 --> 00:43:58,340 But then if you look at the capital cost, which 1215 00:43:58,340 --> 00:44:00,298 is the dark gray color, you can see how massive 1216 00:44:00,298 --> 00:44:02,587 that is in comparison to building natural gas and coal 1217 00:44:02,587 --> 00:44:03,170 firing plants. 1218 00:44:06,050 --> 00:44:07,850 So yeah, I think that's the main thing. 1219 00:44:07,850 --> 00:44:10,720 So because it is more expensive, we 1220 00:44:10,720 --> 00:44:12,858 can't compete with other forms of electricity. 1221 00:44:12,858 --> 00:44:14,650 People buy the electricity that's cheapest, 1222 00:44:14,650 --> 00:44:16,233 not necessarily the electricity that's 1223 00:44:16,233 --> 00:44:19,900 best for our grandchildren or something like that. 1224 00:44:19,900 --> 00:44:22,340 Yeah, so that's why nuclear power isn't more of a thing, 1225 00:44:22,340 --> 00:44:24,830 and that ends my pretty lengthy slide show. 1226 00:44:24,830 --> 00:44:26,830 So do you guys have any questions about anything 1227 00:44:26,830 --> 00:44:27,892 I mentioned? 1228 00:44:27,892 --> 00:44:30,100 If you guys are interested about any of these topics, 1229 00:44:30,100 --> 00:44:32,320 like if any of these things piqued your interest, 1230 00:44:32,320 --> 00:44:33,670 I recommend going to NRC.gov. 1231 00:44:33,670 --> 00:44:35,462 They have a lot of really cool information. 1232 00:44:35,462 --> 00:44:37,530 Let me write that down, because I talk quickly. 1233 00:44:43,552 --> 00:44:46,010 That's basically where I got the majority of my information 1234 00:44:46,010 --> 00:44:48,050 for the slide show, and it is a reliable source. 1235 00:44:48,050 --> 00:44:50,092 It might just be skewed a little bit pro nuclear, 1236 00:44:50,092 --> 00:44:51,540 so just keep that in mind. 1237 00:44:51,540 --> 00:44:53,600 But there's a lot of crazy sources 1238 00:44:53,600 --> 00:44:55,820 out there on the interwebs. 1239 00:44:55,820 --> 00:44:58,850 Take them with a grain of salt. Take NRC.gov with less 1240 00:44:58,850 --> 00:45:00,540 grains of salt than usual. 1241 00:45:00,540 --> 00:45:03,363 Or if one of these things really piqued your interest, 1242 00:45:03,363 --> 00:45:05,030 you guys can take 22.04, which is really 1243 00:45:05,030 --> 00:45:07,610 cool class that's offered here I think this spring, 1244 00:45:07,610 --> 00:45:09,110 and if not this spring, next spring. 1245 00:45:09,110 --> 00:45:11,060 But basically it's called nuclear power society. 1246 00:45:11,060 --> 00:45:12,643 It's taught by a guy named Scott Kemp. 1247 00:45:12,643 --> 00:45:14,990 He talks about all these things and in a lot 1248 00:45:14,990 --> 00:45:16,770 of detail and slower. 1249 00:45:16,770 --> 00:45:18,120 So yeah, cool. 1250 00:45:18,120 --> 00:45:19,770 So thank you guys so much for coming. 1251 00:45:19,770 --> 00:45:21,728 I know you guys could have slept an extra hour, 1252 00:45:21,728 --> 00:45:24,910 but instead you heard me ramble for an hour.