History of thorium
Thorium is naturally a radioactive chemical element, which was discovered in 1828 from the Norwegian mineralogist Morten Thrane Esmark, and named Thor from Jons Jakob Bezelius, which means the “Norse God of Thunder.” Thorium is the most abundant metal found in earth crust and had been scattered million years ago in the galaxy, with the explosion of meteors known as supernova. Thorium generates radioactive gas products, as radon-20 decay. Other decay by-products of thorium are radium and actinium. But, thorium is found in nature as thorium-232, which has a half-life and endures under alpha decay. Thorium decay produces a significant amount of internal heat energy. Thorium is found in the same amount as lead, and four times greater than uranium. Thorium is a cheap metal and plentiful. The pure thorium found in nature is a white metal, where in contact with heated air it ignites brightly with a white light. Thorium source is found in the rare phosphate mineral of monazite, which contains 12% thorium, and monazite resources are predicted to be 12million tones, mostly in India.
What are the byproducts (waste) versus conventional uranium reactors? Half-lives of the products are important!
The natural isotope thorium-232 is a fertile element which has an ability to be used as a nuclear fuel. Thorium-232 is not fissile, it is fertile and it captures neutrons in order to produce, two beta decays, Uranium-233, which is fissile. It is important that thorium fuel don’t need to proceed the isotope division, versus uranium which requires separation of isotopes. The thorium cycle forms uranium-233, which if it divides from the fuel reactor can be used for making nuclear weapons. Thorium as a fertile element transmutes its neutron to uranium-233 with an outstanding fissile fuel. The element produced uranium-233 its isotopes can be separated and in the same time recycled as a fuel. The thorium fissile elements are uranium-233, and uranium-235 or Pu-239.The thorium fuels that produce uranium-233 in thermal reactors are difficult to be constructed rather in fissile materials and it has the ration of more than 1.0 fissile conversion which is called breeding. In addition, the process of thorium fuel continuous, uranium-233 power production increasingly growths the power production of the fuels.
232Th 233Th (n,ỳ)
233Th 233Pa (t1/2=22.3 minutes)
233Pa 233U (t1/2=27.0 decays)
233U fission (n,f)
“The fission of a U-233 nucleus releases about the same amount of energy (200 MeV) as that of U-235.” In thorium fuel reactors, the heterogeneous fuel has a high fissile power called the seed region, in which is separated from the fertile zone of the fuel called blanket. There isn’t any by-product from the use of thorium reactors, to make weapons. In thorium reactor there is a small amount of waste products, and the waste products became safe over hundred years.
What are the advantages and...