Nuclear energy accounts for 10 percent of the world’s energy, and estimates say that by 2050, that number could increase by 2.5 times.
That increase in nuclear energy also means an increase in nuclear waste, so scientists are searching for ways to use the latent energy in nuclear waste for energy-production purposes.
A new study shows that scintillator crystals, which emit light when exposed to gamma radiation, can transform into microbatteries when paired with solar cells.
Around 10 percent of the world’s energy comes from nuclear fission, and while this source doesn’t produce harmful greenhouse gasses, it does have the unfortunate side effect of producing radioactive waste. This nuclear waste is usually stored in spent fuel pools, but some companies and scientists have looked for ways to harness the residual energy in nuclear waste for further energy production.
A new study by scientists at Ohio State University (OSU) created a nuclear waste battery by using scintillator crystals—a high-density material that emits light by absorbing gamma radiation, which makes them well-suited for medical imaging and radiation detection. In this context, these crystals are paired with solar cells that convert emitted light into usable energy. This isn’t grid-scale capability, or even recharge-your-smartphone scale. Instead, these batteries create just hundreds of nanowatts to even a microwatt of power. The results of the study were published in the journalOptical Materials: X.
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“We’re harvesting something considered as waste and by nature, trying to turn it into treasure,” Raymond Cao, a co-author of the study from OSU, said in a press statement.
Cao’s team tested the battery with two types of radioactive material: cesium-137 and cobalt-60. Cesium-137 is one of the most common fission products in nuclear waste, and cobalt-60 (also a byproduct of fission) is used in radiation therapies. When testing with the cesium isotope, the team’s nuclear waste battery registered only 288 nanowatts. But cobalt-60 produced a whopping 1.5 microwatts—enough energy to power microsensors. Although these are tiny numbers, Cao doesn’t see any reason why the right power source couldn’t power things up to the watt level and beyond.
The shape of the scintillator crystal can also have a big impact on the amount of energy produced, as a larger volume can absorb more radiation and therefore produce more light. More surface area also means that solar cells could generate more power.
“These are breakthrough results in terms of power output,” Ibrahim Oksuz, co-author of the study from OSU, said in a press statement. “This two-step process is still in its preliminary stages, but the next step involves generating greater watts with scale-up constructs.”
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In the short term, these batteries could be a perfect fit for places already inundated with radiation, whether that be those aforementioned fuel pools or in nuclear systems used for exploration anywhere from the deep sea to deep space. These batteries are additionally well-suited for this kind of hard-to-reach application because they require little maintenance, and could (to borrow a popular battery slogan) “keep going and going and going.”
Of course, this isn’t the first attempt to transform some facet of the nuclear power industry into useful batteries. In 2020, for example, physicists from the University of Bristol aimed to recycle the carbon-14 isotopes in spent graphite blocks for use in long-lasting diamond batteries. As a bonus, the remaining material would then be much less radioactive after secondary use, making it safer for disposal.
Due in large part to the increasing need to wean humanity off of climate change-exacerbating fossil fuels, the International Atomic Energy Agency (IAEA) forecasts a 2.5 global increase in nuclear power by the year 2050. That being the case, there’s no time like the present to start figuring out how we can turn one reactor’s nuclear trash into energy-producing treasure.
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Darren lives in Portland, has a cat, and writes/edits about sci-fi and how our world works. You can find his previous stuff at Gizmodo and Paste if you look hard enough.