A (Possible) Solution to the worlds energy crisis
The world is currently facing a huge energy crisis. People all over the world are exploring all kinds of possible solutions to this problem, one of these potential promising solution is a nuclear reactor powered by an element called thorium.
Thorium (named after Thor, the Norse god of thunder) is a very common element, more than 3 times as common as uranium, due to its incredibly long half-life of 14.05 billion years! (That’s slightly longer then the age of the entire universe ) In fact, some mining operations have essentially thrown out large amounts of it due to it being in the way of another, more valuable material.
How does a normal reactor work?
In order to explain how a Thorium reactor differs from a uranium fuelled reactor, we must have a brief understanding of how a regular reactor works.
Without going into too much detail about the inner workings of a regular reactor, normally nuclear fuel contains about 5% uranium 235 and the rest is uranium 238. Essentially as the reactor runs, stray neutrons turn the uranium 235 into various elements and more stray neutrons, causing a chain reaction; this process is called nuclear fission. The 238 absorbs some of these stray neutrons and is turned into plutonium. Once the concentration of uranium 235 is less then 0.3% the fuel is considered spent and all that is left is waste. This waste must be stored securely for roughly ~10,000 years until its safe again, or the plutonium can be extracted and turned into nuclear weapons.
How does a Thorium reactor work?
Thorium itself is very stable i.e. it can’t explode or cause any damage and it can’t be used in any kind of nuclear weapon, so it’s very safe. However, it is capable of absorbing neutrons, which results in it becoming unstable and quickly decaying into uranium 233; this can be extracted into a pure uranium 233 concentrate and used as fuel for a reactor. A big difference with this fuel is the lack of uranium 238, which also means no plutonium, resulting in radioactive waste produced by the reactor only needing to be stored for around 300 years and it cant be turned into nuclear weapons. Uranium 233 is also about 6% more efficient then uranium 235.
Unfortunately it is not a flawless system there are a few cons to these reactors. For starters 300 years for the waste product to become safe is still a very long time, even if it is only 3% of current nuclear wastes storage time. Also even though thorium itself can’t be turned into nuclear weapons, it needs to be turned into uranium in order to generate power, which can be turned into weapons. So a lot of extra time and money will need to go into ensuring these places are well protected from potential attacks. Lastly during the power generation process the reactor produces a lot more radiation. It is also slightly easier to control the reaction so its not necessarily more dangerous, however it is a more complicated engineering problem and things such as decommissioning a reactor can be a challenge in itself.
So, should we use it?
It’s hard to say. Whilst a couple of countries are currently researching this very topic, it could still take 10 or more years for a Thorium reactor to be built, although the concept has been proven to work once before. Not a particularly good short term solution. However it’s unlikely a perfect solution for the global energy crisis is coming anytime soon, thorium reactors may allow us to completely remove our dependence on fossil fuels until a better solution can be found.