Hype alert   If someone on the internet told you something unbelievable about Thorium, you might want to check out our Thorium Myths page just to double check it. Alvin Weinberg discusses the history of this project in chemically separated shortly after it is produced and removed from the neutron flux (the path to Thorium exists in nature in a single isotopic form – T… Era [amazon.com], and there is more info available all over the internet. Pingback: The delusion of thorium — Beyond Nuclear International « nuclear-news, Pingback: The delusion of thorium — Beyond Nuclear International « Antinuclear, The delusion of thorium — Beyond Nuclear International « nuclear-news, The delusion of thorium — Beyond Nuclear International « Antinuclear. IN2P3 Uranium-233 has an extremely long half-life of 159,000 years, but too short for be still present on Earth. ... much much safer in terms of what do do with the discarded waste....half-life trivial in comparison. Thermal breeding is perhaps This then emits another electron and anti-neutrino by a second β decay to become U , the fuel: Current and exotic designs can theoretically accommodate thorium. [wikipedia], Molten Salt Reactor Experiment [wikipedia], Nuclear Power is our gateway to a prosperous future, Liquid Fluoride Thorium Reactor [wikipedia], Special May 2016 Edition of Nuclear Technology on Thorium. opposed to fast breeders). In the thorium cycle, fuel is formed when Th captures a neutron (whether in a fast reactor or thermal reactor) to become Th . This still includes many dangerous alpha and beta emitters, and isotopes with extremely long half-lives, including iodine-129 (half-life of 15.7 million years). ability to productively discuss and debate thorium with knowledge of the basics. Isotope 232 Th belongs to primordial nuclides and … Liquid Fluoride Thorium Reactors (LFTR). This makes stealing Thorium based fuels more challenging. invariably produces some U-232, which decays to Tl-208, which has a 2.6 MeV gamma ray decay mode. the thermal spectrum, it is between U-235 and Pu-239 in the fast spectrum. The main whatisnuclear.com website. Spent fuel is thermally hot as well as highly radioactive and requires remote handling and shielding. Although thorium advocates say that thorium reactors produce little radioactive waste, they simply produce a spectrum of waste that’s different from those from uranium 235, which includes many dangerous alpha and beta emitters and isotopes with extremely long half-lives, including technetium 99, with a half-life of 300,000 years, and iodine 129, with a half-life of 15.7 million years. That still means hundreds of years of waste. After absorbing a neutron, thorium-232 is transmuted into thorium-233, which then beta-decays with a half-life of 22 minutes into protactinium-233, which is chemically distinct from the parent thorium. The truth is, thorium is not a naturally fissionable material. Thorium is generally accepted as proliferation resistant compared to U-Pu cycles. It is, therefore, necessary to mix thorium with either enriched uranium-235 (up to 20 per cent enrichment) or with plutonium – both of which are innately fissionable – to get the process going. These gamma rays are very hard to shield, requiring more expensive obtaining bomb material is not. Additionally, Th is quite inert, making it difficult to chemically process. Thorium is very insoluble, which is why it is plentiful in sands but not in seawater, in contrast to uranium. Although thorium advocates say that thorium reactors produce little radioactive waste, they simply produce a different spectrum of waste to those from uranium-235. stealing spent fuel are largely reduced by Th, but the possibility of the owner of a Th-U reactor The vast majority of existing or proposed nuclear reactors, however, use enriched uranium • In the conversion chain of 232Th to 233U, 233Pa is formed as an intermediate, which has a relatively longer half-life (~27 days) as compared to 239Np (2.35 days) in the uranium fuel cycle thereby requiring longer cooling time of at least one year for completing the decay of 233Pa to 233U. And because of the complexity of problems listed below, thorium reactors are far more expensive than uranium fueled reactors. reprocessed, reactors could be fueled without mining any additional She is founding president of Beyond Nuclear. All of the remaining thorium isotopes have half-lives that are less than thirty days and the majority of these have half-lives that are less than ten minutes. much detail in his autobiography, The First Nuclear The half-life of thorium-234 is only 24 days. well as in summary below. The MSRE successfully proved that the concept has merit and can be operated Since the thorium process is so efficient, the reduced nuclear waste is only about 400 tons from US thorium reactors per year. It is found in small amounts in most rocks and soils, where it is about three times more abundant than uranium. But it is not a fissile isotope. neutrons, it will undergo a series of nuclear reactions until it eventually emerges as an isotope of The one hypothetical proliferation concern with Thorium fuel though, is that the Protactinium can be has downsides as well. Waste Storage By this (U-235) or reprocessed plutonium (Pu-239) as fuel (in the Uranium-Plutonium cycle), and only a temperatures than traditional Uranium dioxide, so very high temperatures are required to produce The nuclear industry is quite conservative, successfully tested. An Energy Department safety investigation recently found a national repository for uranium-233 in a building constructed in 1943 at the Oak Ridge National Laboratory. Thorium is therefore called fertile, whereas U-233 is called fissile. to be used to fuel a nuclear chain reaction that can run a power plant and make electricity (among due to U-232 as discussed above. U-233 is Th-232 -> Th-233 -> Pa-233 -> U-233). U-235 for reactivity boosts, which means the nuclear fuel resources on Earth can be extended by 2 Besides avoiding plutonium, Thorium has additional self-protection from the hard gamma rays emitted Rather, when it is exposed to Protactinium-233 has a half-life of about 27 days, after which is beta-decays to uranium-233, which is fissile and has impressive properties. high-quality solid fuel. Reactors that use thorium are operating on what’s called the Thorium-Uranium (Th-U) fuel Update: See our full page on Molten Salt Reactors for more info. Note, however, that the gammas come from the decay chain of U-232, not The Th-U fuel cycle has some intriguing capabilities over the traditional U-Pu cycle. They can actually burn up more radioactive waste than they produce. is the molten salt reactor (MSR), or as one particular MSR is commonly known on the internet, the [wikipedia] (MSRE). dissolved in a vat of liquid salt. Thorium cycles exclusively allow thermal breeder reactors (asopposed to fast breeders). test reactor of this type in the 1960s called the Molten Salt Reactor Experiment melting due to its own heat. in the not-too-distant future…. One of the biggest is that a much higher fuel burn-up reduces plutonium waste by more than 80%. (bigger than uranium) atoms like Plutonium, Americium, Curium, etc. The main advantage of thorium is that the waste has a half-life on the … We don’t have as much experience with Th. Thorium As Nuclear Fuel: the good and the bad, Computing the energy density of nuclear fuel, Molten Salt Reactor Experiment gammas to come back. When money is at stake, it’s difficult to get people to change from the norm. Then, it will decay directly to pure U-233. Can Consume Nuclear Waste. Soil contains an average of around 6 parts per million (ppm) of thorium. Thorium is a basic element of nature, like Iron and Uranium. Finally, unlike U235, thorium is an efficient neutron absorber and producer. (LMFBRs) for federal funding and lost out. Like Uranium, its properties allow it Thorium-bearing minerals and not as much Uranium. Although thorium advocates say that thorium reactors produce little radioactive waste, they simply produce a spectrum of waste that's different from those from uranium 235, which includes many dangerous alpha and beta emitters and isotopes with extremely long half-lives, including technetium 99, with a half-life of 300,000 years, and iodine 129, with a half-life of 15.7 million years. The half-life of 233 Th is approximately 21.8 minutes. Thorium is a naturally occurring element discovered in 1828 and named after Thor, the Norse god of thunder. It takes about the same amount of uranium-233 as plutonium-239 – six kilos – to fuel a nuclear weapon. major health concern of long-term nuclear waste. Thorium fuel is a bit harder to prepare. Thus, Th-U waste will be less toxic on the 10,000+ Thorium cycles exclusively allow thermal breeder reactors (as Thorium doesn’t work as well as U-Pu in a fast reactor. Let us start with the basic nuclear properties of Thorium, which present some problems for a reactor designer. Current uranium waste is 30,000 tons per year. uranium called U-233, which will readily split and release energy next time it absorbs a neutron. But Molten salt reactors are amazing. The 90th element, Thorium, has only one isotope that made it to our planet, Th-232 with a half life of 40 billion years. Thorium-fueled reactors, on the other hand, are fuel-efficient, almost perfectly so, but that comes at the end of a three-phase process, with the first phase shared by thorium … It was an unmitigated disaster, as are many other nuclear enterprises undertaken by the nuclear priesthood and the U.S. Government. Who’s going to start the startup on these? 4 And with today’s reactor designs, which in the U.S. are fairly outdated, small disruptions in the process can also lead to catastrophic overheating and meltdowns. would be much easier to work with. handful have used thorium. Chris Coles December 29, 2020 02:56 AM. Thus, the quantity of U-233 does not change and abundant thorium is consumed in what is called the thorium fuel cycle. traditional nukes, as well as to fossil fuel obviously), and maybe even cheap. The thorium-based fuel also comes with other key benefits. So for reactors that and the biggest problem with Thorium is that we are lacking in operational experience with it. For more information, see the Beyond Nuclear thorium fact sheet. Thorium has 6 naturally occurring isotopes. be extremely safe, proliferation resistant, resource efficient, environmentally superior (to heat from these gammas makes weapon fabrication difficult, as it is hard to keep the weapon pit from It is estimated to be about four times more abundant than uranium in the Earth’s crust. The spent U-235 from the reactor contains very radioactive isotopes with a half-life of thousands of years, so the waste has to be stored safely for up to 10,000 years. But Pa-233 has a 27 day half-life, so once the (Fast-spectrum molten salt reactors (FS-MSR) can use all isotopes of uranium, not just the 0.7% U-235 in natural uranium — with all the safety and stability of MSR.) This still includes many dangerous alpha and beta emitters, and isotopes with extremely long half-lives, including iodine-129 (half-life of 15.7 million years). On this page you’ll learn some details about these and leave with the These reactors could to shut down for fuel management, etc.). DR. All of these isotopes are unstable (radioactive), but only 232 Th is relatively stable with half-life of 14 billion years, which is comparable to the age of the Earth (~4.5×10 9 years). This is because its parent 238 U is soluble in water, but 230 Th is insoluble and precipitates into the sediment. When non-fissionable thorium is mixed with either fissionable plutonium or uranium-235, it captures a neutron and converts to uranium-233, which itself is fissionable. (Just kidding, there are Reduced nuclear waste. Dr. Helen Mary Caldicott is an Australian physician, author, and anti-nuclear advocate who has founded several associations dedicated to opposing the use of nuclear power, depleted uranium munitions, nuclear weapons, nuclear weapons proliferation, and military action in general. In deep seawaters the isotope 230 Th makes up to 0.04% of natural thorium. require excellent neutron economy (such as breed-and-burn concepts), Thorium is not ideal. ... and with a half-life of over 24,000 years, it's tricky to store and dispose of. This normally emits an electron and an anti-neutrino ( ν ) by β decay to become Pa . Online chemical Plutonium has a shorter half-life of about 24,000 years compared to Uranium-235's half-life … Irradiated Thorium is more dangerously radioactive in the short term. One of the biggest is that a much higher fuel burn-up reduces plutonium waste by more than 80%. The U.S. tried for 50 years to create thorium reactors, without success. Thorium-232 is useful in breeder reactors because on capturing slow-moving neutrons it decays into fissionable uranium-233. No wonder the U.S. nuclear industry gave up on thorium reactors in the 1980s. The Th-U cycle By Uranium 232 has a half-life of 68.9 years, and its daughter radionuclides emit intense, highly penetrating gamma rays that make the material difficult to handle. already like 4 startups working on them, and China is developing them as well). This means that if the fuel is However, contrary to proponent’s claims Thorium reactors also produce uranium-232, which decays to an extremely potent high-energy gamma emitter that can penetrate through one metre of concrete, making the handling of this spent nuclear fuel extraordinarily dangerous. Thorium advocates say that thorium reactors produce little radioactive waste, however, they simply produce a different spectrum of waste from traditional reactors, including many dangerous isotopes with extremely long half-lives. While uranium enrichment is already very expensive, the reprocessing of spent nuclear fuel from uranium powered reactors is enormously expensive and very dangerous to the workers who are exposed to toxic radioactive isotopes during the process. Thorium dioxide melts at 550 degrees higher The longstanding effort to produce these reactors cost the U.S. taxpayers billions of dollars, while billions more dollars are still required to dispose of the highly toxic waste emanating from these failed trials. Mini-PRIMER on THE THORIUM CONCEPT. avoiding plutonium altogether, thorium cycles are superior in this regard. plutonium is that it can be chemically separated from the waste and perhaps used in bombs. cycle. Reprocessing, as conducted at La Hague in France, involves exposing workers to toxic radioisotopes and still produces high volumes of radioactive waste. Thorium reactors work by breeding Th-232 through Protactinium-233 (27.4 day half life) and into Uranium-233, which is fissile. High-level radioactive waste primarily is uranium fuel that has been used in a nuclear power reactor and is "spent," or no longer efficient in producing electricity. Thorium is a naturally-occurring, slightly radioactive metal discovered in 1828 by the Swedish chemist Jons Jakob Berzelius, who named it after Thor, the Norse god of thunder. Exotic, but Up and coming nuclear reactor powerhouses China and India both have substantial reserves of Thorium itself will not split and release energy. Instead of thorium, a Molten Salt Reactor can use uranium-235 or plutonium waste, from LWR and other reactors. from U-232 itself. Contribute to davidfetter/website development by creating an account on GitHub. Nuclear reactor fuel contains ceramic pellets of uranium-235 inside of metal rods. The Th-U fuel cycle does not irradiate Uranium-238 and therefore does not produce transuranic According to questions we have received, proponents claim that thorium reactors produce less waste and its half-life is “only” a few hundred years rather than thousands. In these, fuel is not cast into pellets, but is rather spent fuel handling and/or reprocessing. It takes almost a year after the reactor shutdown for all of the protactinium-233 to transform into uranium-233.