WHAT IS THORIUM?
The only naturally occurring source of nuclear fuel is Uranium. Thorium is not a fuel, technically (not fissile).
Thorium naturally occurs in the Earth's crust
, at a concentration of around twelve ppm (roughly the same as lead, and three times that of uranium). Although thorium is radioactive, its fourteen billion-year half-life
is so long that most of the Earth's original thorium is still there
. The primary ore for thorium is the mineral monazite
, which can have up to 10% thorium content by mass; a few other minerals, such as thorianite and euxenite, also contain significant amounts of thorium.
Although many countries have large thorium reserves, thorium is not very widely mined; its applications as a metal are limited by its radioactivity
, which makes it potentially dangerous if inhaled or ingested
. Ironically, thorium's high density and atomic number make it an effective radiation shield
, although lead and depleted uranium are more frequently used.
Thorium is not fissile
, so it cannot be used to make an atomic bomb or nuclear reactor
. However, when thorium is inserted into a nuclear reactor, the high neutron flux causes some of the thorium to transmute to U-233, which is fissile
. U-233 can then be used to sustain the nuclear reaction and transmute more thorium, creating a closed nuclear fuel cycle
, which makes thorium potentially valuable as an energy source. Historically, natural uranium has been cheap enough as a fuel to make thorium unnecessary. However, with the recent spike in uranium prices, some governments have developed plans to build thorium-fueled reactors in case of a disruption in the uranium supply.
FAST BREEDER TECHNOLOGY- REACTOR.
In the 1950's, a group of scientists invented a new reactor which revolutionized the world. It's name was the Fast Breeder
. It gets this name from its ability to "breed" fuel.
It can produce up to 3% less fuel than it uses
. One Fast Breeder has been running from when it was built in 1958. It also is unbelievably faster than the normal reactor
. The Fast Breeder uses liquid metal sodium instead of water
to heat up pipes in the reactor, but it uses water to turn the turbine
In a Fast Breeder, there are two coolants. The liquid metal sodium
is one, and water
is the other. The liquid sodium comes into the core from a containment building. The containment building stores the sodium at a controlled temperature so the sodium won't damage anything. The second coolant, water, is heated and made into steam by the liquid sodium, after the sodium is heated. The water is then sent to the turbine.
This reactor also has pumps all over the place to move the liquid metal sodium. Being metal, it doesn't want to move on it's own. The pumps move the liquid sodium to the steam generator where the water is heated and transformed into steam and transported to the turbine.
Fast breeders don't have moderators
, therefore earning the name fast breeder. It is still experimental because there is nothing to absorb stray sub-atomic particles inside of the fuel rods, which could lead to a huge meltdown or a hole splitting in the chamber.
In all normal reactors, a moderator is used. Moderators are small rods which are placed inside of the fuel rods. They are strategically placed to slow down the chain reaction of atom splitting and to absorb the stray atoms that may cause damage the fuel rod chamber.
A steam generator is what causes the water in a reactor to turn into steam. The liquid metal sodium goes through a pipe which heats up the water around it. This occurs only in the Fast Breeder, because in a normal reactor, there is no liquid metal sodium
Every reactor needs a set of control rods. These are made of a mixture of materials that are very strong and can take a large amount of heat. They are placed inside of the fuel rods and do the same sort of thing that moderators can. They are meant to stop the chain reaction of atoms inside of the fuel rods, which, in turn, stops the plant. They are also able to stop the coolant from flowing.
FAST BREEDERS AND INDIA
Regards, and thanks for reading.