18 Jul 2017

Diamond batteries made from nuclear waste

Diamond batteries made from nuclear waste
 

Are diamonds scientist best friends?

Nuclear waste is one of the biggest challenges of this century.  Surprisingly, disposal of nuclear waste is not the top challenge. Actually, nuclear waste is made of valuable radioactive isotopes that could be repurposed either for industrial applications, medicine or to produce more fuel.  The real challenge with nuclear waste has to do with long-term storage – either until it stops being radioactive or until physicists and chemists come up with a way to use it. Considering that the first option takes almost 6,000 years to happen, it makes sense that the second option is the focus of many scientists around the world. 

According to the Nuclear Energy Institute, the United States alone produced 76,430 metric tons of nuclear waste over the past four decades. With this huge amount of waste, you could imagine that it’s probably hard to tell what is actually waste and what could somehow become a valuable resource. The United Kingdom, on the other hand has less than 2,000 metric tonnes of high radiation waste, a much more manageable size for testing purposes. That is why scientist from the University of Bristol found a way to convert all these thousands of tonnes of nuclear waste into laboratory-made diamond batteries. 

How is this possible?

Let’s start from the beginning. Nuclear power plants use a process called nuclear fission. This consists of splitting radioactive uranium to generate heat that vaporizes water into steam. Ultimately, this steam turns turbines that generate electricity. The first-generation reactors used graphite blocks to slow down neutrons and keep the nuclear fission process more efficient. The nuclear waste generated from the fission process gets deposited in the graphite and changes the carbon inside the blocks, turning it into carbon-14. 

This carbon-14 is too dangerous to be released into the environment because of its radioactive properties. Instead of interring it, Bristol’s scientists came up with a way to take the carbon-14 out of the graphite blocks and turn it into diamonds that not only shine, but can also generate electricity. These diamonds are made from the gaseous form generated when heating the radioactive graphite. After being submitted to high temperatures and low pressures, the gas becomes a man-made diamond – almost like a magic trick. 

As if this wasn’t crazy enough, you must be wondering how that diamond generates power. When a lab-made diamond is exposed to radiation, it generates a small electrical current. Non-radioactive diamonds can absorb harmful emissions and allow even more electricity, which makes the battery nearly 100% efficient. 

A bright and shiny future

A lab-made diamond battery is pretty impressive but even more impressive is how long it can last: it will only be half used up by the year 7746. Because they last thousands of years, it could change the reality of planes, satellites and even spacecraft by increasing flight times considerably. It could also enhance the reliability of medical devices, such as pacemakers. 

In conclusion, this development is not only a very efficient way to repurpose radioactive waste but it can also change many industries. It also doesn’t generate emissions or require maintenance. A ‘brilliant’ solution for too many challenges at once.