A team of physicists and chemists from the University of Bristol has grown a man-made diamond that uses nuclear waste to generate electricity – providing a solution to the problems of nuclear waste, clean electricity generation and battery life.

The innovative method for radioactive energy was presented at the Cabot Institute’s sold-out annual lecture, ‘Ideas to change the world’, on 25 November. The University of Bristol’s Cabot Institute carries out cutting-edge, cross-disciplinary research on the social and environmental challenges arising from how we live with, depend on and affect our planet. It focuses on six major issues: global environmental change, food, water and energy security, natural hazards and future cities and communities. As part of its energy security work, the institute is host to the South West Nuclear Hub, a research network that supports the safe operation of current and future generation nuclear systems in the UK and around the world.

Disposing of nuclear waste, or more pertinently, safely channelling the valuable isotopes from spent nuclear fuel, is one of the great technical challenges of the 21st century. The Bristol team’s work centred on nuclear waste from Britain’s ageing Magnox reactors, which are now being decommissioned. The result: a man-made diamond, able to produce a charge simply by being placed in close proximity to a radioactive source.

Cabot Institute member Tom Scott, Professor in Materials in the university’s Interface Analysis Centre, which conducts world-leading materials research, said: “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. There are no moving parts involved, no emissions generated and no maintenance required, just direct electricity generation.”

The first generation Magnox reactors used graphite blocks to moderate the reaction in nuclear power plants, but decades of exposure have left the UK with 95,000 tonnes of blocks that are now classed as nuclear waste because the inert carbon in them has turned into radioactive carbon-14.

The Bristol team has demonstrated a prototype ‘diamond battery’ using Nickel-63 as the radiation source. However, they are now working to significantly improve efficiency by utilising carbon-14. The blocks are heated to drive out the carbon-14 gas, which is then collected and, using low pressures and high temperatures, turned into man-made diamonds. The process significantly reduces the radioactivity of the blocks, reducing the cost and challenge of safely storing this nuclear waste.

Dr Neil Fox from the University of Bristol’s School of Chemistry explained: “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.”

These ‘diamond batteries’ offer low power relative to current battery technologies. However, their lifespan could revolutionise the powering of devices over long timescales.  Using carbon-14 the battery would take 5,730 years to reach 50 per cent power.

Professor Scott added: “We envision these batteries to be used in situations where it is not feasible to charge or replace conventional batteries. 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.”

(via University of Bristol and New Atlas)

Featured image: The new technology turns diamonds into nuclear batteries that can last thousands of years (Credit: Shenki/Despositphotos)