1 00:00:01,920 --> 00:00:06,440 Speaker 1: Welcome to brain Stuff. Production of I Heart Radio Hey 2 00:00:06,480 --> 00:00:10,799 Speaker 1: brain Stuff Lauren Volga bam here. As human driven climate 3 00:00:10,880 --> 00:00:14,200 Speaker 1: change makes our planet less pleasant to live on, nuclear 4 00:00:14,240 --> 00:00:18,360 Speaker 1: power is getting more attention. A solar and wind energy 5 00:00:18,440 --> 00:00:21,720 Speaker 1: can help cut greenhouse gas emissions too, But if a 6 00:00:21,800 --> 00:00:25,760 Speaker 1: solution can be found to climate change, nuclear power is 7 00:00:25,840 --> 00:00:30,080 Speaker 1: probably going to be part of it. Although nuclear power 8 00:00:30,160 --> 00:00:33,559 Speaker 1: doesn't produce the climate altering gases that create a problem 9 00:00:33,600 --> 00:00:36,479 Speaker 1: with other sources of electricity, it does carry with it 10 00:00:36,560 --> 00:00:41,080 Speaker 1: certain risks for starters. Disposing of radioactive waste from nuclear 11 00:00:41,080 --> 00:00:44,199 Speaker 1: power plants presents a difficult problem, and what to do 12 00:00:44,280 --> 00:00:48,200 Speaker 1: with such dangerous byproducts. Also, what happens if the core 13 00:00:48,240 --> 00:00:53,120 Speaker 1: melts down and creates an environmental catastrophe as happened in Chernobyl, Ukraine. 14 00:00:53,159 --> 00:00:57,840 Speaker 1: In there are other concerns as well, but given our 15 00:00:57,840 --> 00:01:01,320 Speaker 1: current energy predicament, there are enty of reasons to keep 16 00:01:01,320 --> 00:01:06,880 Speaker 1: plugging away and making nuclear power safer. The nuclear reactors 17 00:01:06,920 --> 00:01:10,200 Speaker 1: are run by fission, a nuclear chain reaction in which 18 00:01:10,240 --> 00:01:13,160 Speaker 1: adams split to produce energy, or, in the case of 19 00:01:13,240 --> 00:01:17,960 Speaker 1: nuclear bombs, a massive explosion. For the article this episode 20 00:01:18,000 --> 00:01:20,280 Speaker 1: is based on, has to Fork spoken by email with 21 00:01:20,319 --> 00:01:23,120 Speaker 1: Steve Kron, a professor in the Department of Civil and 22 00:01:23,240 --> 00:01:28,600 Speaker 1: Environmental Engineering at Vanderbilt University. He said approximately four hundred 23 00:01:28,600 --> 00:01:32,520 Speaker 1: and fifty nuclear reactors are an operation worldwide, and they 24 00:01:32,560 --> 00:01:36,720 Speaker 1: all need fuel. He noted that for the most part, 25 00:01:36,920 --> 00:01:40,920 Speaker 1: these reactors operate on uranium two thirty five, and the 26 00:01:41,000 --> 00:01:44,640 Speaker 1: nations that partially recycle the fuel France, Russia, and a 27 00:01:44,640 --> 00:01:47,960 Speaker 1: few other countries combine it with recycled plutonium two thirty 28 00:01:48,040 --> 00:01:52,840 Speaker 1: nine to make what's called mixed oxide fuel. Plutonium is 29 00:01:52,840 --> 00:01:56,040 Speaker 1: a byproduct of used fuel from a nuclear reactor, and 30 00:01:56,120 --> 00:02:00,160 Speaker 1: it's cool that it can help recycle uranium. However, it's 31 00:02:00,240 --> 00:02:03,600 Speaker 1: highly toxic and is the most frequently used material for 32 00:02:03,720 --> 00:02:07,480 Speaker 1: nuclear weapons, which is one reason why scientists have continued 33 00:02:07,520 --> 00:02:13,359 Speaker 1: to explore other options, which brings us to thorium. Thorium 34 00:02:13,400 --> 00:02:16,440 Speaker 1: is an element that was discovered in eight and named 35 00:02:16,440 --> 00:02:20,320 Speaker 1: after Thorpe, the Norse god of thunder, and some scientists 36 00:02:20,360 --> 00:02:23,080 Speaker 1: think that it's the answer to our nuclear power problems. 37 00:02:23,840 --> 00:02:28,120 Speaker 1: Thorium is a slightly radioactive, relatively abundant metal, about as 38 00:02:28,160 --> 00:02:32,639 Speaker 1: abundant as tin and more abundant than uranium. It's also widespread, 39 00:02:32,720 --> 00:02:36,720 Speaker 1: with particular concentrations in India, Turkey, Brazil, the United States, 40 00:02:36,760 --> 00:02:41,360 Speaker 1: and Egypt. But it is important to note that thorium 41 00:02:41,480 --> 00:02:45,560 Speaker 1: isn't a fuel like uranium. The difference is that uranium 42 00:02:45,639 --> 00:02:49,239 Speaker 1: is fissile, meaning that it produces a sustainable chain reaction 43 00:02:49,480 --> 00:02:51,520 Speaker 1: if you can get enough uranium in one spot at 44 00:02:51,560 --> 00:02:55,120 Speaker 1: one time. Thorium, on the other hand, is not fissile. 45 00:02:55,480 --> 00:02:59,320 Speaker 1: It's what scientists call fertile, meaning that if you bombard 46 00:02:59,320 --> 00:03:02,600 Speaker 1: the thorium with neutrons essentially jump started in a reactor 47 00:03:02,680 --> 00:03:06,400 Speaker 1: fueled with material like uranium, it can transmute into a 48 00:03:06,560 --> 00:03:10,680 Speaker 1: uranium isotope uranium two thirty three, which is fissile and 49 00:03:10,800 --> 00:03:15,440 Speaker 1: suitable for creating power. Thorium was used in some of 50 00:03:15,480 --> 00:03:19,640 Speaker 1: the earliest nuclear physics experiments. Marie Curry and Ernest Rutherford 51 00:03:19,680 --> 00:03:23,160 Speaker 1: both worked with it. Uranium and plutonium became more heavily 52 00:03:23,200 --> 00:03:27,280 Speaker 1: associated with nuclear processes during World War Two because they 53 00:03:27,320 --> 00:03:32,320 Speaker 1: provided the clearest path to making bombs for power generation, 54 00:03:32,360 --> 00:03:36,520 Speaker 1: though thorium has some real benefits. Uranium two thirty three 55 00:03:36,560 --> 00:03:39,880 Speaker 1: formed from thorium is a more efficient fuel than uranium 56 00:03:39,920 --> 00:03:43,360 Speaker 1: two thirty five or plutonium, and its reactors may be 57 00:03:43,520 --> 00:03:46,360 Speaker 1: less likely to melt down because they can operate up 58 00:03:46,400 --> 00:03:50,720 Speaker 1: to higher temperatures. In addition, less plutonium is produced during 59 00:03:50,720 --> 00:03:54,960 Speaker 1: reactor operation, and some scientists argue that thorium reactors could 60 00:03:55,040 --> 00:03:58,520 Speaker 1: destroy the tons of dangerous plutonium that have been created 61 00:03:58,600 --> 00:04:02,760 Speaker 1: and stockpiled since the ninth teen fifties. And not only that, 62 00:04:03,080 --> 00:04:06,160 Speaker 1: A fleet of reactors operating on thorium and uranium two 63 00:04:06,160 --> 00:04:08,840 Speaker 1: thirty three is thought by some scientists to be more 64 00:04:08,960 --> 00:04:13,880 Speaker 1: proliferation resistant, since more sophisticated technology is needed to separate 65 00:04:14,000 --> 00:04:16,680 Speaker 1: uranium two thirty three out of the waste products and 66 00:04:16,920 --> 00:04:21,960 Speaker 1: use it to make bombs. There are downsides to thorium, however. 67 00:04:22,680 --> 00:04:25,680 Speaker 1: One is that thorium and uranium two thirty three are 68 00:04:25,839 --> 00:04:30,800 Speaker 1: more dangerously radioactive to chemically process. For that reason, they 69 00:04:30,800 --> 00:04:33,800 Speaker 1: are harder to work with. It's also more difficult to 70 00:04:33,839 --> 00:04:38,680 Speaker 1: manufacture uranium two thirty three fuel rods. Also, as noted earlier, 71 00:04:38,880 --> 00:04:43,320 Speaker 1: thorium is not a fuel. Kron said, if we're going 72 00:04:43,360 --> 00:04:46,160 Speaker 1: to power our planet using a fuel cycle that employs 73 00:04:46,160 --> 00:04:49,719 Speaker 1: thorium and uranium two thirty three, sufficient uranium two thirty 74 00:04:49,720 --> 00:04:52,240 Speaker 1: three must be produced in other types of reactors to 75 00:04:52,440 --> 00:04:56,240 Speaker 1: fuel the initial uranium two thirty three reactors, if that 76 00:04:56,320 --> 00:04:59,920 Speaker 1: can be accomplished. Methods to chemically process thorium two thirty 77 00:05:00,000 --> 00:05:03,360 Speaker 1: two and uranium two thirty three and manufacture fuel from 78 00:05:03,400 --> 00:05:07,680 Speaker 1: them are fairly well established. However, facilities to accomplish these 79 00:05:07,680 --> 00:05:12,799 Speaker 1: processes wouldn't need to be constructed. There are several ways 80 00:05:12,839 --> 00:05:16,360 Speaker 1: thorium could be applied to energy production. Oh One way 81 00:05:16,440 --> 00:05:19,839 Speaker 1: under investigation now is to use solid thorium and uranium 82 00:05:19,839 --> 00:05:23,080 Speaker 1: two thirty two fuel in a conventional water cooled reactor, 83 00:05:23,440 --> 00:05:27,200 Speaker 1: similar to modern uranium based power plants. In fact, more 84 00:05:27,240 --> 00:05:30,560 Speaker 1: than twenty reactors worldwide have been operated with fuel made 85 00:05:30,560 --> 00:05:35,000 Speaker 1: of thorium and uranium two thirty three. Another prospect that 86 00:05:35,040 --> 00:05:38,320 Speaker 1: has been exciting to scientists and nuclear power advocates is 87 00:05:38,360 --> 00:05:42,520 Speaker 1: the molten salt reactor. In these plants, fuel is dissolved 88 00:05:42,520 --> 00:05:45,240 Speaker 1: in liquid salt that also acts as the coolant for 89 00:05:45,320 --> 00:05:48,600 Speaker 1: the reactor. The salt has a high boiling point, so 90 00:05:48,760 --> 00:05:51,960 Speaker 1: they can be more efficient in electricity generation, and even 91 00:05:52,080 --> 00:05:56,040 Speaker 1: huge temperature spikes will not lead to massive reactor accidents, 92 00:05:56,080 --> 00:05:59,520 Speaker 1: such as the disaster that occurred at Fukushima. It might 93 00:05:59,600 --> 00:06:02,120 Speaker 1: sound like this kind of reactor is almost the stuff 94 00:06:02,160 --> 00:06:05,479 Speaker 1: of science fiction, but just such a reactor was operated 95 00:06:05,520 --> 00:06:08,240 Speaker 1: in the United States in the nineteen sixties and is 96 00:06:08,240 --> 00:06:16,159 Speaker 1: currently being built of the Gobi Desert in China. Today's 97 00:06:16,160 --> 00:06:18,840 Speaker 1: episode is based on the article Coldgorian Power the next 98 00:06:18,920 --> 00:06:21,599 Speaker 1: generation of nuclear reactors on how stuff works dot Com, 99 00:06:21,680 --> 00:06:24,360 Speaker 1: written by Jesslin Shields. Brain Stuff is production of I 100 00:06:24,440 --> 00:06:26,760 Speaker 1: Heart Radio in partnership with how stuff works dot Com 101 00:06:26,800 --> 00:06:29,800 Speaker 1: and is produced by Tyler klang Ur. More podcasts from 102 00:06:29,800 --> 00:06:33,080 Speaker 1: my heart Radio, visit the heart Radio app, Apple Podcasts, 103 00:06:33,160 --> 00:06:35,000 Speaker 1: or wherever you listen to your favorite shows.