Thorium is a naturally occurring radioactive chemical element with the symbol Th and atomic number 90. It was discovered in 1828 by the Norwegian mineralogist Morten Thrane Esmark and identified by the Swedish chemist Jöns Jakob Berzelius and named after Thor, the Norse god of thunder. Thorium produces a radioactive gas, radon-220, as one of its decay products. Secondary decay products of thorium include radium and actinium. Thorium was once commonly used as the light source in gas mantles and as an alloying material, but these applications have declined due to concerns about its radioactivity. Characteristics Physical properties A close view of a thorium crystal Pure thorium is a silvery-white metal that is air-stable and retains its luster for several months. Powdered thorium metal is often pyrophoric and requires careful handling. Chemical properties Thorium's oxide is ThO2. Compounds Thorium compounds are stable in the +4 oxidation state. Isotopes
Energie nucléaire : Nucléaire du futurLe cycle thorium Le thorium (Th 232) est un matériau fertile, abondant dans la nature. Par absorption d’un neutron, puis décroissance radioactive, il produit du Pa 233 puis du U 233, isotope fissile. Ce dernier est lui-même intéressant, car sa fission produit un peu plus de neutrons que celle de U 235 ou de Pu 239 dans un spectre thermique. Ces différentes raisons ont conduit, dans les années cinquante, à s’intéresser de près à la filière U 233- thorium ; des combustibles ont été fabriqués et utilisés dans différents réacteurs, dont le REP expérimental américain de Shippingport (Pennsylvanie), le HTR de Fort St. Vrain (Colorado) et le THTR allemand. Au cours des dernières années, la filière thorium a fait l’objet d’un nouvel examen, à la fois parce que cette filière produit beaucoup moins de transuraniens* et parce que robotique et télémanipulation ont fait des progrès considérables, limitant peut-être les inconvénients liés au rayonnement γ. Le mécanisme de la spallation
Development of Tiny Thorium Reactors Could Wean the World Off Oil In Just Five YearsAn abundant metal with vast energy potential could quickly wean the world off oil, if only Western political leaders would muster the will to do it, a UK newspaper says today. The Telegraph makes the case for thorium reactors as the key to a fossil-fuel-free world within five years, and puts the ball firmly in President Barack Obama's court. Thorium, named for the Norse god of thunder, is much more abundant than uranium and has 200 times that metal's energy potential. Thorium is also a more efficient fuel source -- unlike natural uranium, which must be highly refined before it can be used in nuclear reactors, all thorium is potentially usable as fuel. The Telegraph says thorium could be used as an energy amplifier in next-generation nuclear power plants, an idea conceived by Nobel laureate Carlo Rubbia, former director of CERN. Known as an accelerator-driven system, it would use a particle accelerator to produce a proton beam and aim it at lump of heavy metal, producing excess neutrons.
New age nuclearCredit: Justin Randall What if we could build a nuclear reactor that offered no possibility of a meltdown, generated its power inexpensively, created no weapons-grade by-products, and burnt up existing high-level waste as well as old nuclear weapon stockpiles? And what if the waste produced by such a reactor was radioactive for a mere few hundred years rather than tens of thousands? It may sound too good to be true, but such a reactor is indeed possible, and a number of teams around the world are now working to make it a reality. What makes this incredible reactor so different is its fuel source: thorium. Named after Thor, the warlike Norse god of thunder, thorium could ironically prove a potent instrument of peace as well as a tool to soothe the world’s changing climate. But nuclear power comes with its own challenges. A thorium reactor is different. That may not sound like much, but small changes in the global average can mask more dramatic localised disruptions in climate.
China Takes Lead in Race for Clean Nuclear Power | Wired ScienceChina has officially announced it will launch a program to develop a thorium-fueled molten-salt nuclear reactor, taking a crucial step towards shifting to nuclear power as a primary energy source. The project was unveiled at the annual Chinese Academy of Sciences conference in Shanghai last week, and reported in the Wen Hui Bao newspaper (Google English translation here). If the reactor works as planned, China may fulfill a long-delayed dream of clean nuclear energy. The United States could conceivably become dependent on China for next-generation nuclear technology. At the least, the United States could fall dramatically behind in developing green energy. “President Obama talked about a Sputnik-type call to action in his SOTU address,” wrote Charles Hart, a a retired semiconductor researcher and frequent commenter on the Energy From Thorium discussion forum. In addition to their safety, MSRs can consume various nuclear-fuel types, including existing stocks of nuclear waste. See Also:
Re-fuel Every 100 Years With the New Thorium CarBy: Amanda Froelich, True Activist. If you haven’t yet been amazed by the hybrid car that runs on air or the water-powered engine, this vehicle is sure to make you think twice about the alternative forms of transportation which will one day rule the road. The new Thorium car, created by a company called Laser Power Systems, is completely emission-free, turbine-free, and is electricity generated. Fueled by nuclear thorium lasers, this engine only needs 8 grams of fuels every 100 years. It seems many countries and military agencies have been experimenting with this type of energy to power vehicles for a number of years. Go Thorium sheds insight to its long-time study: “What China is attempting is to turn the nuclear clock back to the mid-1960s, when Oak Ridge successfully operated a reactor with fuel derived from thorium and cooled with molten salts. It is quite clear that modern day nuclear reactors are no longer needed. Sources: Collective Evolution Thorium Fuel Benefits, IAEA
Thorium : le nucléaire alternatif safe et propre ?? - Actualité - DiscussionsLe Thorium Qu'est-ce que c'est ? Le thorium est un élément radioactif naturel comme l'uranium. C'est un métal de la famille des actinide, de symbole Th, de numéro atomique 90 et de couleur argenté. Découvert en 1829 par Jöns Jacob Berzelius, il est nommé d'après Thor, dieu scandinave du tonnerre. C'est en 1898 que sa radioactivité est découverte indépendamment par deux chercheurs : la physicienne polonaise naturalisée française Marie Curie et le chimiste allemand Gerhard Carl Schmidt. Détaillons le schéma. La blanket sert aussi de bouclier à la cuve du réacteur contre les dommage dû aux neutrons et aux emission gamma. --------------- Losers IV : le forum des losers/sans-amis/VDM & co :o | N'essayez MÊME PAS le second degrée avec moi.
China bets on thoriumHigh performance access to file storage China has committed itself to establishing an entirely new nuclear energy programme using thorium as a fuel, within 20 years. The LFTR (Liquid Fluoride Thorium Reactor) is a 4G reactor that uses liquid salt as both fuel and coolant. The thorium fuel cycles produce almost no plutonium, and fewer higher-isotope nasties, the long-lived minor actinides. Thorium reactors are also safer, with the fuel contained in a low-pressure reactor vessel, which means smaller (sub-500MWe) reactors may be worth building. The design has also had its champions in Europe, but planning restrictions and a continent-wide policy obsession with conservation and renewables have seen little commercial action. A private company founded by Kazuo Furukawa, designer of the Fuju reactor, called International Thorium Energy & Molen-Salt Technology Inc (iThEMS) aims to produce a small (10MW) reactor within five years. There's a good 15-minute introduction to LFTR, here.
Thorium(Updated March 2014) Thorium is more abundant in nature than uranium.It is fertile rather than fissile, and can only be used as a fuel in conjunction with a fissile material such as recycled plutonium.Thorium fuels can breed fissile uranium-233 to be used in various kinds of nuclear reactors.Molten salt reactors are well suited to thorium fuel, as normal fuel fabrication is avoided. The use of thorium as a new primary energy source has been a tantalizing prospect for many years. Extracting its latent energy value in a cost-effective manner remains a challenge, and will require considerable R&D investment. This is occurring preeminently in China, with modest US support. Nature and sources of thorium 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. When pure, thorium is a silvery white metal that retains its lustre for several months. Thorium as a nuclear fuel