University of Bristol develops battery out of nuclear waste that can last 5,000 years

Carbon-14 from nuclear power plants could be recycled to make better batteries

A team of physicists and chemists at the University of Bristol have developed a low-power battery out of nuclear waste that, they claim, will run for 5,730 years before it even reaches 50 per cent of its initial power.

The device required the team to develop their own man-made diamond, which is able to generate a small electrical current when placed in a radioactive field.

The technology was presented at the Cabot Institute's recent Ideas to Change the World annual lecture at the University.

"There are no moving parts involved, no emissions generated and no maintenance required, just direct electricity generation.

"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," claimed Tom Scott, professor in materials at the University of Bristol's Interface Analysis Centre.

The team demonstrated a working prototype using nickel-63 as the radiation source. They are now working to improve the efficiency of the prototype design by using salvaged carbon-14.

Carbon-14 is a radioactive version of carbon generated in the graphite blocks used in nuclear power plants to moderate the nuclear reactions. Concentrated at the surface of these blocks, most of the radioactive material embodied in the graphite can be remove and incorporated into a diamond to produce a nuclear-powered battery, the researchers claim.

The UK currently holds just under 95,000 tonnes of graphite blocks and extracting the carbon-14 from them for use in low-power batteries would reduce the cost of storing or re-processing the waste.

"Carbon-14 was chosen as a source material because it emits a short-range radiation, which is quickly absorbed by any solid material. 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," claimed Dr Neil Fox at the University of Bristol's School of Chemistry.

The researchers envisage the batteries being embedded in low-power applications in which it would be difficult or costly to frequently change batteries, such as pacemakers, satellites, drones and even spacecraft.

While one gram of carbon-14 per battery would deliver about 15 joules of energy per day - less than a standard AA battery - the researchers believe that they could run continuously for more than 5,000 years.

The device is one of a string of developments in low-power embedded technologies that have been unveiled recently. It comes just a month after the University of Cambridge showed off a printable low-powered transistor design intended for Internet of Things applications.