Frédéric Paulussen / Unsplash, CC BY-SA
Bill Lee, Bangor University and Michael Rushton, Bangor University
Nuclear power has provided the UK with low-carbon electricity for over 60 years and now generates 17% of the country's electricity. As of mid-2018, 15 nuclear reactors were the largest low-carbon energy source in the country. Of these, only Sizewell B will remain in operation in 12 years. The only new facility under construction is Hinkley Point C and with a total capacity of 3.26 gigawatts would cover only 8% of the current electricity needs in the UK.
The Climate Change Committee advises the UK government on efforts to achieve net zero emissions by 2050. Oddly enough, his proposals do not say anything about nuclear energy and occasionally associate it with "other low-carbon generation". It supports a massive increase in renewable energy generation and the continued burning of natural gas, using CO2 capture and storage technology to mop up the emitted CO₂. Elsewhere, there are plans to electrify transportation, heating and industrial processes, ie batteries in cars and heat pumps that run on electricity in households and factories.
While this would reduce the amount of gas and oil burned, it would at least double the amount of electricity the national grid will need by 2050. Perhaps this could be achieved with renewable energy and battery storage to cover those moments when the sun is not shining and there is no wind to generate green energy. Unfortunately, battery technology is currently not powerful enough to store energy on this scale.
Even today's largest battery shops can only provide a few hours of emergency power, which is not always enough to cover longer periods of low wind or shorter hours of daylight in winter. Battery technology is constantly improving, but it may not be fast enough to meet increasing demand for electricity. The introduction of many electric vehicles could further limit the supply of batteries and possibly even increase their costs.
The capture and storage of carbon is also not a proven technology, so it would be unwise to lay too many eggs in this basket. Aside from other technical problems – the storage of the CO₂ generated by burning natural gas is a potential safety risk – the unexpected release of underground gas could choke life on the surface. While plans are underway to make “green hydrogen” the new lifeblood of the economy, producing enough low-carbon fuel would cost a lot of electricity. Can renewables produce enough to do this while leaving enough to increase electricity needs elsewhere?
Put simply, we need to start rebuilding the UK's nuclear power generation capacity.
A new generation of reactors
Future nuclear reactors won't just be large boilers that generate steam to power turbines that generate electricity. The heat generated during the nuclear reaction can be diverted to energy processes that are currently difficult to decarbonize.
Take the heating in buildings, for example. Heat cooler than 400 ° C can be extracted after the turbine and pumped into district heating systems, replacing fossil fuels like natural gas. This is a process that is already being carried out every day in waste incineration plants across Europe.
High temperature heat (between 400 and 900 ° C) could be dissipated from near the reactor before it reaches the turbine in a nuclear power plant. It could be used to power processes that produce low-carbon hydrogen, ammonia, and synthetic fuels for ships and jets. This heat could also supply industries such as the steel, cement, glass, and chemical industries, which otherwise often use fossil fuel burners.
This flexibility fits perfectly with renewable energies. While the sun is shining and the wind is blowing, nuclear reactors can continue to produce hydrogen or other fuels that act as energy storage – a standby source that can be burned to produce additional energy when needed. This energy could also heat houses or produce aluminum, steel, brick, cement and glass. When it is cloudy and quiet, the reactor can still generate electricity for the grid.
Nuclear reactors have evolved to produce more than just electricity. Royal Society, author provided
The smaller reactors currently being developed around the world typically generate around 300 megawatts of electricity each. They are much cheaper to build than the current fleet of larger reactors producing over 1,000 megawatts, such as the UK's Hinkley Point C. Because they burn fuel more efficiently, this new generation of reactors also produces much less nuclear waste.
Many also include passive safety measures that can flood a superheat reactor with cold water or remove the fuel source in the event of problems. They serve several purposes: either electricity for the grid with low renewable energy production, or hydrogen and other fuels with high electricity production. Since these reactors are smaller, they can even be set up in industrial parks to supply neighboring factories with electricity and heat.
We do not believe that it is possible to achieve net zero emissions in the remaining time without building new nuclear reactors. Fortunately, the new models waiting to be built can generate so much more than just electricity.
Bill Lee, Ser Cymru Professor of Materials in Extreme Environments at Bangor University; and Michael Rushton, Lecturer in Nuclear Power at Bangor University
This article is republished by The Conversation under a Creative Commons license. Read the original article.