A+-+what+is+a+thorium+reactor?

__What is a thorium reactor? __ Alysha Lum – SCH4U1-02 – November 17th, 2010  __**What is thorium? – Properties and Structure **__  __**What is a thorium reactor? **__  __**Thorium vs. Uranium Reactors **__  __**Where was thorium all this time? Where is it now?**__  - //Energy from Thorium// Blog: [] - Thorium energy video/propaganda: media type="youtube" key="eU3cUssuz-U?fs=1" height="385" width="480"
 * - Lustrous, silver-white metal; mildly radioactive – you could carry one unprotected and unharmed
 * - Found at bottom of periodic table, in the actinides group with similar elements (note how close to uranium it is)
 * - Elements are dense because there are a lot of neutrons and protons in their nuclei
 * - Actinides spin off particles and decompose into less reactive elements
 * - When many atoms of one actinide are compacted together, their nuclei erupt, releasing energy
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- Work as chain reaction: when a stray neutron is shot at the compacted cluster, they break apart – fission
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- If there are millions of clusters also compacted, fissioned particles from first fission will knock into nearby groups
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- This chain reaction only occurs with actinides
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- Purpose of reactors is to harness energy released by controlling it (regulating temperature & # of stray electrons)
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- A thorium reactor is simply one that uses thorium nuclei, rather than the widely-used uranium
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- Countless nuclei undergo fission, creating radioactive material; when water is pumped past it, it turns to steam, which powers an energy-creating turbine
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- Has liquid fluoride salts which fill tubes in reactor core; when too hot from fission, salts expand, flow out, slow fission – this makes reactor self-regulating
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- Fluoride salts must be chemically stable, impervious to radiation, have little inclination for neutron absorption, be able to dissolve high amounts of uranium, thorium and fission products, have min. melting temperatures, high heat capacities
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- A mix of lithium and beryllium fluoride salts is one example; mixture has LiF and BeF2 – note that both have dipole-dipole forces as well as London Forces which can be linked to aforementioned properties
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- These kinds of reactors can operate at high temperatures without pressurization, can dissolve uranium and thorium in liquid fluoride salt, mixtures impervious to radiation due to ionic bonds
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- Thorium leaves behind miniscule amount of waste when used as fuel, which only needs to be stored for a hundred years vs. the few thousand years other nuclear by-products need to be stored for
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- Uranium reactors require very rare uranium-235 (an isotope of uranium) that must be refined from U-238, and leave highly radioactive plutonium-239 behind
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- Literally tons of thorium in the US alone; is 3-4 times more common than uranium in nature; it is more common than Sn, W, Hg, or Ag in Earth’s crust; also found on other planets, and our moon has lots
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- thorium is efficient – doesn’t need to be refined, and as earlier described reaction occurs, it produces more neutrons per collision than usual fuels
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- The more neutrons per collision = more energy generated = less total fuel consumed = less radioactive waste
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- New liquid fluoride thorium reactor (LFTR) is estimated to be roughly 50% more efficient than uranium reactors
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- 1 tonne of thorium produces as much energy as 200 tonnes of uranium, or 3 500 000 tonnes of coal
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- Plants would be smaller, less expensive & less dangerous than uranium reactor plants (see Chernobyl disaster)
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- Thorium reactors can have almost no risk of meltdown, based on how thorium dissolves in liquid fluoride salts
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- However, thorium reactors require specialized containers that can withstand corrosive salts
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- At Oak Ridge National Lab, Alvin Weinberg proved efficiency of thorium in many tests from 50’s to early 70’s
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- US government built uranium-fuelled reactors instead in the 60’s, during the Cold War
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- Plutonium by-products from the nuclear fission was used as material for nuclear weapons to combat Soviet Union
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- Now, India is working a lot with thorium reactors; they have over 25% of the world’s thorium resources
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- Russia, France, China, and some other places in Europe are looking more into thorium reactors as well
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- MOX fuel program (part of nuclear cycle where plutonium is irradiated, processed and reused) is being reviewed
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- Thorium-plutonium or thorium-uranium fuel as a substitute can be burned with little modification to existing reactors (this is a seed-blanket approach)
 * <span style="font-family: Tahoma,Geneva,sans-serif;">- Having new facilities made is extremely costly (in the billions) thus thorium reactors are not widespread
 * __Other Links__**

<span style="font-family: Tahoma,Geneva,sans-serif;">__**Bibliography**__ <span style="font-family: Tahoma,Geneva,sans-serif;">(2008, July 25). "OPINION: Safeguards and the thorium alternative." Businessline. Retrieved October 24 2010 from <http://elibrary.bigchalk.com>

<span style="font-family: Tahoma,Geneva,sans-serif;">Ambrose Evans-Pritchard. (2010, August 30). "Thorium could fuel civilisation cleanly for thousands of years to come [Edition 2]." Daily Telegraph. Retrieved October 24 2010 from <http://elibrary.bigchalk.com> <span style="font-family: Tahoma,Geneva,sans-serif;"> <span style="font-family: Tahoma,Geneva,sans-serif;">Martin, R. (2010, January). The New Nuke. Wired, (18), 114-119. <span style="font-family: Tahoma,Geneva,sans-serif;"> <span style="font-family: Tahoma,Geneva,sans-serif;">Reparaz, A., Rogers, P. (2003, September 01). Between MOX and a hard place. Bulletin of the Atomic Scientists, (5), 46, Retrieved October 24 2010 from <http://elibrary.bigchalk.com> <span style="font-family: Tahoma,Geneva,sans-serif;"> <span style="font-family: Tahoma,Geneva,sans-serif;">Sorensen, Kirk. (2010, March 18). Thinking nuclear? THINK THORIUM. Machine Design, (5), 22, Retrieved October 24 2010 from <http://elibrary.bigchalk.com>