A UK-based consortium has reported that nuclear power plants (NPPs) could provide the heat necessary to enable a technology to capture carbon dioxide directly from the atmosphere (an approach known as ‘direct air capture’ or DAC, for short). The consortium comprised EDF Sizewell C (a UK subsidiary of the French EDF group and holder of 20% of the proposed Sizewell C NPP project), UK company Strata Technology, the University of Nottingham (in England), Doosan Babcock (a UK subsidiary of the South Korean Doosan group) and Atkins (a UK subsidiary of the Canadian SNC-Lavalin group).

The consortium had successfully completed a research and development project, funded by the UK Department of Business, Energy and Industrial Strategy (BEIS) under its Greenhouse Gas Removal Innovation competition. Experiments conducted with a laboratory-based pilot plant had allowed to consortium to complete the process design for a demonstration plant, that would be able to extract 100 t of carbon dioxide a year from the atmosphere. The consortium was seeking further funding for their project, under Phase 2 of the BEIS innovation competition.

The DAC technology developed by the consortium would see large volumes of air placed in direct contact with a solid surface composed of chemical materials called sorbents. The carbon dioxide in the air would adhere to the sorbents. The whole process would be driven by heat. Existing DAC processes relied on electricity. Siting the proposed new-technology plant at an NPP, and using heat from the NPP, would greatly reduce the amount of electricity required. And nuclear energy was low carbon energy.  

The sorbents would subsequently be treated to remove the carbon dioxide, which would then be compressed, either for re-use or storage. The sorbents could also be reused.

The consortium’s current proposal was to site the demonstration plant at the yet-to-be built Sizewell C NPP. The heat would be provided by steam, used to drive the NPP’s electricity-generating turbines. The demonstration plant would occupy a site measuring about 20 m by 12 m and was projected to cost about £3-million.

Success would result in a full-scale plant being built, also at Sizewell C, integrated into the NPP. The full-scale plant would use up to 400 MWt of heat to capture 1.5-million tons of carbon dioxide a year. This would, the consortium pointed out, almost offset all British railway transport emissions.

Sizewell was already the site of two NPPs. These were the two-reactor Sizewell A, now being decommissioned, and the one-reactor Sizewell B, which was the UK’s only pressurised water reactor NPP, and which was currently planned to close in 2035 (but EDF was planning to extend its life until 2055). The UK Government would make its decision on whether or not to give approval to Sizewell C early next month. If approval was given, the UK Government would take a 20% share in the project and construction would probably begin sometime late next year.