Graphene membranes could make nuclear decontamination 100 times less energy intensive

According to research by the University of Manchester, graphene could help reduce the energy cost of producing heavy water and decontamination in nuclear power plants by over 100 times compared with current technologies. This could lead to the reduction of CO2 emissions associated with heavy water production by up to a million tonnes per year.

The team, led by Dr Marcelo Lozada-Hidalgo, has demonstrated fully scalable prototypes of graphene membranes capable of producing heavy water more efficiently, leading to greener and cheaper nuclear power.

Producing heavy water, which is needed by the nuclear industry to generate clean-energy, is an expensive process. Graphene’s unique material properties means it has the potential to effectively separate sub-atomic particles making this process more efficient and cost-effective.

Separating hydrogen isotopes is a huge task for nuclear fission and future fusion plants. Thousands of tons of isotopic mixtures are processed every year. Yet, producing just 1kg of heavy water consumes enough energy to power an average household for an entire year.

“This is a crucial milestone in the path to taking this revolutionary technology to industrial application,” said Dr Lozada-Hidalgo. “The potential gains are high enough to justify its introduction even in the highly conservative nuclear industry.”

Last year, the same group of researchers found that graphene can efficiently sieve hydrogen isotopes. But the industrial opportunities of this discovery were not analysed because there were no membranes or fabrication methods suitable for scalable manufacturing at the time.

Now, the Manchester group has developed fully scalable prototype membranes and demonstrated the isotope separation in pilot scale studies. They found that the high efficiency of the separation would allow for a significant reduction of the input amount of raw isotope mixtures that needs to be processed. This reduces both the capital costs and the energy requirements.

Even larger energy savings are anticipated for tritium decontamination, which the researchers say is a major global concern.