10 percent of the energy of the planet is obtained from nuclear power plants. Someone would like to see this percentage grow, because fission is a low emissions technology and could help the transition to a carbon neutral world. Others consider it a dangerous road, because even nuclear power plants produce polluting substances, in the form of complicated and expensive radioactive waste to manage and dispose of. Finding users to these radioactive waste is one of the roads that could make nuclear energy truly sustainable. And it is in this direction that an invention just presented in the Optical Materials magazine goes: X: a battery capable of producing energy by recycling the residual radioactivity of the waste from fission reactors.
The new “nuclear battery” works thanks to a two -phase procedure. The first phase provides for the transformation of radiation emitted by the waste in light, and is entrusted to a sparkler, that is, a crystal with the ability to issue photons, and therefore light, when it is crossed by charged particles, such as those emitted by radioactive elements. Once the light is obtained, the battery then transforms it into electricity, exploiting common solar cells.
If the theory is relatively simple, obtaining a prototype capable of generating a significant quantity of electricity has obviously not equally easy. But by optimizing materials and procedures, the authors of the study – a team of US researchers led by Ohio State University – has achieved the goal.
Their battery measures just 4 cubic centimeters, and was tested with two sources of gamma radiation: Cesio 137 and cobalt 60, two of the most common waste of the melting reactors. With the first, the battery managed to generate 288 Nanowatt of Potenza, with the second – which emits many more gamma rays – has reached 1.5 microwatt, a quantity of energy enough to feed small sensors.
At the moment, the inventors of the battery offer its use in areas where nuclear waste are produced, where there are high levels of environmental gamma rays, and where it could be useful for feeding monitoring sensors and other small electronic equipment. With the right source of radiation, however, it may be possible to increase the rendering of the battery in terms of electricity, and therefore imagining it even more ambitious uses, helping for example to recycle the radioactivity produced in the large nuclear slag deposits, transforming these harmful waste that currently represent only a problem, into useful sources of energy at low emissions.
“It is a very promising concept of nuclear battery,” underlines Ibrahim Oksuz, an Ohio State engineer who has collaborated in the development of the prototype. “We still have a lot of room for improvement, but I believe that in the future this approach will carve out an important role both in the field of energy production and in the sensors industry”.