Thorium

Thorium is a chemical element; it has symbol Th and atomic number 90. Thorium is a weakly radioactive light silver metal which tarnishes olive grey when it is exposed to air, forming thorium dioxide; it is moderately soft, malleable, and has a high melting point. Thorium is an electropositive actinide whose chemistry is dominated by the +4 oxidation state; it is quite reactive and can ignite in air when finely divided.

Swedish chemist (1779–1848)

radiometric dating method based on the degree to which secular equilibrium has been achieved between the parent U-234 and the daughter Th-230

nuclear fuel cycle using 232Th as fertile material, which absorbs neutrons to become into 233U (the nuclear fuel), which fissions to produce energy

thumb|Thorotrast bottle

type of nuclear reactor that uses molten material as fuel

The THTR-300 was a thorium cycle high-temperature nuclear reactor rated at 300 MW electric (THTR-300) in Hamm-Uentrop, West Germany. It started operating in 1983, synchronized with the grid in 1985, operated at full power in February 1987 and was shut down on 1 September 1989. The THTR-300 served as a prototype high-temperature reactor (HTR) to use the TRISO pebble fuel produced by the AVR, an experimental pebble bed operated by VEW (Vereinigte Elektrizitätswerke Westfalen). The THTR-300 cost €2.05 billion and was predicted to cost an additional €425 million through December 2009 in decommissi

volcanic complex on the lunar far side

type of nuclear reactor design

Clock based on an atomic nucleus instead of an atom

radioactive toothpaste produced on Germany

Geological phenomenon

nuclear energy extracted from thorium isotopes