Which is the correct expression for Half-Life?
The time required for half of the original population of radioactive atoms to decay is called the half-life. The relationship between the half-life, T1/2, and the decay constant is given by T1/2 = 0.693/λ.
What is the half-life for uranium 238?
about 4.5 billion years
How dangerous is uranium 238?
Because uranium decays by alpha particles, external exposure to uranium is not as dangerous as exposure to other radioactive elements because the skin will block the alpha particles. Ingestion of high concentrations of uranium, however, can cause severe health effects, such as cancer of the bone or liver.
What happens when uranium 238 absorbs a neutron?
By capturing a neutron, uranium-238 becomes uranium-239 that rapidly changes by beta radiation into neptunium-239. This neptunium is transformed then by beta radiation, after 3 days on average, into a new nucleus: plutonium-239. This radionuclide is fissile, like uranium-235.
What happens when uranium 235 absorbs a neutron?
A uranium-235 atom absorbs a neutron and fissions into two new atoms (fission fragments), releasing three new neutrons and some binding energy. 2. One of those neutrons is absorbed by an atom of uranium-238 and does not continue the reaction.
Is it illegal to have uranium?
Yes, you have to be special licensed to possess quantities of Uranium and/or Plutonium of greater than 1 gram. If you are not licensed, then it is illegal to possess either element. You can buy either uranium ore or purified uranium from United Nuclear.
Can thorium be used in place of uranium?
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.
What are the downsides to thorium?
The fuel in nuclear fission reactors is usually based on the metal oxide. Emission of gamma rays: Presence of Uranium-232 in irradiated thorium or thorium based fuels in large amounts is one of the major disadvantages of thorium nuclear power reactors. It can result in significant emissions of gamma rays.
Is thorium named after Thor?
In 1815, for example, Berzelius isolated a new element from a mineral sent to him from the Swedish mining town of Falun and named it thorium after the Scandinavian god of thunder, Thor.
Does thorium produce nuclear waste?
Compared to uranium reactors, thorium reactors produce far less waste and the waste that is generated is much less radioactive and much shorter-lived.