Transforming nuclear waste into a thousand-year energy solution

Environmental campaign group RePlanet proposes an innovative solution to repurpose nuclear waste as fuel for advanced fast reactors, potentially providing zero-carbon electricity for Europe for up to 1,000 years. Their report argues that the energy potential in natural uranium has been underutilized, with nuclear ‘waste’ posing more of a political challenge than an environmental threat. By using this fuel in fast-neutron reactors, nuclear waste would be transformed and generate energy. Although the economics of fast reactors are unproven, RePlanet advocates for resources currently allocated for disposal to be redirected towards a fast reactor programme, transforming a burden into a circular economic activity. They urge European green parties to reconsider their opposition to nuclear energy.

Unlocking the energy potential of nuclear waste

RePlanet’s report highlights that Europe’s nuclear power reactors have safely provided clean electricity for decades, but they utilise less than 1% of the energy potential in natural uranium. By recycling used nuclear fuel for advanced fast reactors, this untapped energy could be harnessed to generate zero-carbon electricity, significantly reducing the need for fossil fuels. Furthermore, calculations based on current uranium inventories reveal sufficient energy in nuclear ‘waste’ to power Europe at current electrical consumption levels for 600-1,000 years. Considering unconventional uranium and thorium resources, nuclear fuel could supply carbon-free energy for tens of thousands of years.

What are fast-neutron reactors?

Traditional reactors produce energy by splitting atoms, specifically uranium-235, through a process called nuclear fission.
Fast-neutron reactors are a type of advanced nuclear reactors that use fast neutrons to sustain the fission process. In contrast to conventional reactors, which utilize slow or “thermal” neutrons, fast-neutron reactors do not require a moderator to slow down the neutrons. This leads to some key differences and advantages.
1. Fuel efficiency: Fast-neutron reactors are capable of using a wider range of isotopes as fuel, including uranium-238 and plutonium-239, which are typically considered as waste in conventional reactors. This improves fuel efficiency and helps in reducing nuclear waste.
2. Waste reduction: Fast-neutron reactors not only use long-lived radioactive waste as fuel but also produce waste with shorter half-lives. This means the waste generated is less hazardous and requires a shorter storage time before it becomes harmless.
3. Breeding capabilities: Some fast-neutron reactors, known as breeder reactors, can actually generate more fissile material than they consume. They convert non-fissile isotopes, like uranium-238, into fissile isotopes, like plutonium-239, while producing energy. This can extend the supply of nuclear fuel and makes nuclear power a more sustainable energy source.
4. Safety features: Fast-neutron reactors can be designed with passive safety features that make them less susceptible to accidents. For example, they can have a negative temperature coefficient of reactivity, which means that as the reactor’s temperature increases, its reactivity (and thus power) decreases, creating an inherent safety mechanism.

Fast reactors are designed to extract more energy from used nuclear fuel and reduce waste by up to 80%. Scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have developed techniques like pyroprocessing to recycle used fuel without separating pure plutonium, thus reducing proliferation risks. This new generation of fast-neutron reactors would “eliminate it as a ‘waste’ concern via a carbon-free waste-to-energy process”, with most remaining fission products returning to radioactivity levels comparable to the original uranium ore within 200-300 years. This breakthrough has the potential to simplify and scale back current deep geological disposal strategies.

Supporting a Net Zero Europe with fast reactors

RePlanet proposes repurposing nuclear materials and building an urgent programme of fast reactor build-outs to support wind and solar power in achieving a net-zero economy in Europe. Deploying fast reactors in such a way that reduces grid congestion and increases the security of supply would facilitate the deployment of wind, solar, and nuclear power generation for the majority of electrical power generation and heat supply in a net-zero Europe.

While the economics of fast reactors are currently unproven, RePlanet believes that if resources intended for deep geological disposal of spent fuel were redirected into a fast reactor programme that would enable the re-use of that fuel, this would turn a burden into a useful part of a legitimate circular economic activity. The group calls on green parties of Europe to end their opposition to nuclear energy, particularly in light of the Intergovernmental Panel on Climate Change (IPCC) Synthesis Report’s emphasis on the urgency of cutting carbon emissions to meet the Paris goal of 1.5°C.

Overcoming challenges and embracing advanced nuclear power

Two main factors currently hinder the adoption of pyroprocessing and fast reactor technology: lack of financial incentive and proliferation fears. Raw uranium is relatively cheap, and Light-Water Reactors (LWRs) are cheaper and quicker to build. Approving new reactor designs takes years, discouraging the construction of different reactors, including fast reactors. However, pyroprocessing addresses proliferation concerns by mixing plutonium with uranium and highly radioactive actinides, making theft and weapon creation difficult.

Additionally, pyroprocessing plants with fast reactors can be built on former LWR sites, reducing security risks by eliminating the need for fuel transportation. Nuclear energy is a stable, large-scale source of carbon-free electricity, and Argonne scientists are focused on making fuel recycling safer, cheaper, and more efficient. Research projects are exploring small modular reactors and various fast reactor types, as well as cost reduction techniques.

In conclusion, by harnessing the energy potential of nuclear waste through the use of fast reactors, RePlanet’s proposal can transform waste into a circular economic activity, providing carbon-free electricity for Europe up to a thousand years and possibly beyond. This innovative solution could pave the way towards a net-zero Europe, where wind, solar, and nuclear power work together to create a sustainable, eco-friendly future.