WEBVTT - Could Thorium Revamp Nuclear Energy? 0:00:01.920 --> 0:00:06.440 Welcome to brain Stuff. Production of I Heart Radio Hey 0:00:06.480 --> 0:00:10.799 brain Stuff Lauren Volga bam here. As human driven climate 0:00:10.880 --> 0:00:14.200 change makes our planet less pleasant to live on, nuclear 0:00:14.240 --> 0:00:18.360 power is getting more attention. A solar and wind energy 0:00:18.440 --> 0:00:21.720 can help cut greenhouse gas emissions too, But if a 0:00:21.800 --> 0:00:25.760 solution can be found to climate change, nuclear power is 0:00:25.840 --> 0:00:30.080 probably going to be part of it. Although nuclear power 0:00:30.160 --> 0:00:33.559 doesn't produce the climate altering gases that create a problem 0:00:33.600 --> 0:00:36.479 with other sources of electricity, it does carry with it 0:00:36.560 --> 0:00:41.080 certain risks for starters. Disposing of radioactive waste from nuclear 0:00:41.080 --> 0:00:44.199 power plants presents a difficult problem, and what to do 0:00:44.280 --> 0:00:48.200 with such dangerous byproducts. Also, what happens if the core 0:00:48.240 --> 0:00:53.120 melts down and creates an environmental catastrophe as happened in Chernobyl, Ukraine. 0:00:53.159 --> 0:00:57.840 In there are other concerns as well, but given our 0:00:57.840 --> 0:01:01.320 current energy predicament, there are enty of reasons to keep 0:01:01.320 --> 0:01:06.880 plugging away and making nuclear power safer. The nuclear reactors 0:01:06.920 --> 0:01:10.200 are run by fission, a nuclear chain reaction in which 0:01:10.240 --> 0:01:13.160 adams split to produce energy, or, in the case of 0:01:13.240 --> 0:01:17.960 nuclear bombs, a massive explosion. For the article this episode 0:01:18.000 --> 0:01:20.280 is based on, has to Fork spoken by email with 0:01:20.319 --> 0:01:23.120 Steve Kron, a professor in the Department of Civil and 0:01:23.240 --> 0:01:28.600 Environmental Engineering at Vanderbilt University. He said approximately four hundred 0:01:28.600 --> 0:01:32.520 and fifty nuclear reactors are an operation worldwide, and they 0:01:32.560 --> 0:01:36.720 all need fuel. He noted that for the most part, 0:01:36.920 --> 0:01:40.920 these reactors operate on uranium two thirty five, and the 0:01:41.000 --> 0:01:44.640 nations that partially recycle the fuel France, Russia, and a 0:01:44.640 --> 0:01:47.960 few other countries combine it with recycled plutonium two thirty 0:01:48.040 --> 0:01:52.840 nine to make what's called mixed oxide fuel. Plutonium is 0:01:52.840 --> 0:01:56.040 a byproduct of used fuel from a nuclear reactor, and 0:01:56.120 --> 0:02:00.160 it's cool that it can help recycle uranium. However, it's 0:02:00.240 --> 0:02:03.600 highly toxic and is the most frequently used material for 0:02:03.720 --> 0:02:07.480 nuclear weapons, which is one reason why scientists have continued 0:02:07.520 --> 0:02:13.359 to explore other options, which brings us to thorium. Thorium 0:02:13.400 --> 0:02:16.440 is an element that was discovered in eight and named 0:02:16.440 --> 0:02:20.320 after Thorpe, the Norse god of thunder, and some scientists 0:02:20.360 --> 0:02:23.080 think that it's the answer to our nuclear power problems. 0:02:23.840 --> 0:02:28.120 Thorium is a slightly radioactive, relatively abundant metal, about as 0:02:28.160 --> 0:02:32.639 abundant as tin and more abundant than uranium. It's also widespread, 0:02:32.720 --> 0:02:36.720 with particular concentrations in India, Turkey, Brazil, the United States, 0:02:36.760 --> 0:02:41.360 and Egypt. But it is important to note that thorium 0:02:41.480 --> 0:02:45.560 isn't a fuel like uranium. The difference is that uranium 0:02:45.639 --> 0:02:49.239 is fissile, meaning that it produces a sustainable chain reaction 0:02:49.480 --> 0:02:51.520 if you can get enough uranium in one spot at 0:02:51.560 --> 0:02:55.120 one time. Thorium, on the other hand, is not fissile. 0:02:55.480 --> 0:02:59.320 It's what scientists call fertile, meaning that if you bombard 0:02:59.320 --> 0:03:02.600 the thorium with neutrons essentially jump started in a reactor 0:03:02.680 --> 0:03:06.400 fueled with material like uranium, it can transmute into a 0:03:06.560 --> 0:03:10.680 uranium isotope uranium two thirty three, which is fissile and 0:03:10.800 --> 0:03:15.440 suitable for creating power. Thorium was used in some of 0:03:15.480 --> 0:03:19.640 the earliest nuclear physics experiments. Marie Curry and Ernest Rutherford 0:03:19.680 --> 0:03:23.160 both worked with it. Uranium and plutonium became more heavily 0:03:23.200 --> 0:03:27.280 associated with nuclear processes during World War Two because they 0:03:27.320 --> 0:03:32.320 provided the clearest path to making bombs for power generation, 0:03:32.360 --> 0:03:36.520 though thorium has some real benefits. Uranium two thirty three 0:03:36.560 --> 0:03:39.880 formed from thorium is a more efficient fuel than uranium 0:03:39.920 --> 0:03:43.360 two thirty five or plutonium, and its reactors may be 0:03:43.520 --> 0:03:46.360 less likely to melt down because they can operate up 0:03:46.400 --> 0:03:50.720 to higher temperatures. In addition, less plutonium is produced during 0:03:50.720 --> 0:03:54.960 reactor operation, and some scientists argue that thorium reactors could 0:03:55.040 --> 0:03:58.520 destroy the tons of dangerous plutonium that have been created 0:03:58.600 --> 0:04:02.760 and stockpiled since the ninth teen fifties. And not only that, 0:04:03.080 --> 0:04:06.160 A fleet of reactors operating on thorium and uranium two 0:04:06.160 --> 0:04:08.840 thirty three is thought by some scientists to be more 0:04:08.960 --> 0:04:13.880 proliferation resistant, since more sophisticated technology is needed to separate 0:04:14.000 --> 0:04:16.680 uranium two thirty three out of the waste products and 0:04:16.920 --> 0:04:21.960 use it to make bombs. There are downsides to thorium, however. 0:04:22.680 --> 0:04:25.680 One is that thorium and uranium two thirty three are 0:04:25.839 --> 0:04:30.800 more dangerously radioactive to chemically process. For that reason, they 0:04:30.800 --> 0:04:33.800 are harder to work with. It's also more difficult to 0:04:33.839 --> 0:04:38.680 manufacture uranium two thirty three fuel rods. Also, as noted earlier, 0:04:38.880 --> 0:04:43.320 thorium is not a fuel. Kron said, if we're going 0:04:43.360 --> 0:04:46.160 to power our planet using a fuel cycle that employs 0:04:46.160 --> 0:04:49.719 thorium and uranium two thirty three, sufficient uranium two thirty 0:04:49.720 --> 0:04:52.240 three must be produced in other types of reactors to 0:04:52.440 --> 0:04:56.240 fuel the initial uranium two thirty three reactors, if that 0:04:56.320 --> 0:04:59.920 can be accomplished. Methods to chemically process thorium two thirty 0:05:00.000 --> 0:05:03.360 two and uranium two thirty three and manufacture fuel from 0:05:03.400 --> 0:05:07.680 them are fairly well established. However, facilities to accomplish these 0:05:07.680 --> 0:05:12.799 processes wouldn't need to be constructed. There are several ways 0:05:12.839 --> 0:05:16.360 thorium could be applied to energy production. Oh One way 0:05:16.440 --> 0:05:19.839 under investigation now is to use solid thorium and uranium 0:05:19.839 --> 0:05:23.080 two thirty two fuel in a conventional water cooled reactor, 0:05:23.440 --> 0:05:27.200 similar to modern uranium based power plants. In fact, more 0:05:27.240 --> 0:05:30.560 than twenty reactors worldwide have been operated with fuel made 0:05:30.560 --> 0:05:35.000 of thorium and uranium two thirty three. Another prospect that 0:05:35.040 --> 0:05:38.320 has been exciting to scientists and nuclear power advocates is 0:05:38.360 --> 0:05:42.520 the molten salt reactor. In these plants, fuel is dissolved 0:05:42.520 --> 0:05:45.240 in liquid salt that also acts as the coolant for 0:05:45.320 --> 0:05:48.600 the reactor. The salt has a high boiling point, so 0:05:48.760 --> 0:05:51.960 they can be more efficient in electricity generation, and even 0:05:52.080 --> 0:05:56.040 huge temperature spikes will not lead to massive reactor accidents, 0:05:56.080 --> 0:05:59.520 such as the disaster that occurred at Fukushima. It might 0:05:59.600 --> 0:06:02.120 sound like this kind of reactor is almost the stuff 0:06:02.160 --> 0:06:05.479 of science fiction, but just such a reactor was operated 0:06:05.520 --> 0:06:08.240 in the United States in the nineteen sixties and is 0:06:08.240 --> 0:06:16.159 currently being built of the Gobi Desert in China. Today's 0:06:16.160 --> 0:06:18.840 episode is based on the article Coldgorian Power the next 0:06:18.920 --> 0:06:21.599 generation of nuclear reactors on how stuff works dot Com, 0:06:21.680 --> 0:06:24.360 written by Jesslin Shields. Brain Stuff is production of I 0:06:24.440 --> 0:06:26.760 Heart Radio in partnership with how stuff works dot Com 0:06:26.800 --> 0:06:29.800 and is produced by Tyler klang Ur. More podcasts from 0:06:29.800 --> 0:06:33.080 my heart Radio, visit the heart Radio app, Apple Podcasts, 0:06:33.160 --> 0:06:35.000 or wherever you listen to your favorite shows.