Researchers at the University of Bristol have developed a way to use nuclear waste to generate electricity in a battery.
The team, led by Tom Scott, Professor in Materials in the University’s Interface Analysis Centre and a member of the Cabot Institute, have grown a man-made diamond that, when placed in a radioactive field, is able to generate a small electrical current.
Unlike the majority of electricity-generation technologies, which use energy to move a magnet through a coil of wire to generate a current, the man-made diamond is able to produce a charge simply by being placed close to, or around, a radioactive source.
“There are no moving parts involved, no emissions generated and no maintenance”
“There are no moving parts involved, no emissions generated and no maintenance required, just direct electricity generation,” said Prof Scott. “By encapsulating radioactive material inside diamonds, we turn a long-term problem of nuclear waste into a nuclear-powered battery and a long-term supply of clean energy.” A full explanation of how this works is explained in the video below:
Improving on the prototype
The team has demonstrated a prototype ‘diamond battery’ using Nickel-63 as the radiation source but is now working to significantly improve the efficiency of the battery by using carbon-14, a radioactive version of carbon. This results from the graphite blocks used to moderate the reaction in nuclear power plants. Research at Bristol has shown that the radioactive carbon-14 is concentrated at the surface of these blocks, making it possible to process it to remove the majority of the radioactive material. The extracted carbon-14 is then incorporated into an artificial diamond to produce the battery.
The UK currently holds almost 95,000 tonnes of these graphite blocks and by extracting carbon-14 from them, their radioactivity decreases, reducing the cost and challenge of safely storing this nuclear waste.
Safe and reliable
“Carbon-14 was chosen as a source material because it emits a short-range radiation, which is quickly absorbed by any solid material,” said Dr Neil Fox from the School of Chemistry at Bristol. “This would make it dangerous to ingest or touch with your naked skin, but safely held within diamond, no short-range radiation can escape. In fact, diamond is the hardest substance known to man, there is literally nothing we could use that could offer more protection.”
“We see these batteries used in situations where it is not feasible to charge or replace conventional batteries”
The actual amount of carbon-14 in each battery has yet to be decided but one battery with just 1g of carbon-14 would deliver 15 Joules per day. While this compares to 14000J from a 20g AA battery in a day, the carbon-14 battery would take 5,730 years to reach 50 per cent power.
“We see these batteries used in situations where it is not feasible to charge or replace conventional batteries,” said Prof Scott, who is also co-director of the newly opened South West Nuclear Hub at the University. “Obvious applications would be in low-power electrical devices where long life of the energy source is needed, such as pacemakers, satellites, high-altitude drones or even spacecraft.”