District heating from new nuclear plants?

Date: 2 March 2018

Nuclear power stations represent the most centralized power generation option there is. Huge, capital-intensive, sited in remote areas and inflexible in operation, nuclear energy is the antithesis of today’s transition to renewables and small-scale, decentralized energy sources.

Yet, like large fossil-fuelled power stations, nuclear plants generate so much ‘waste’ heat that first generation nuclear plants were sited on coasts or adjacent to large rivers to dissipate this heat. (Coal-fired power stations, do the same through cooling towers, save for stations sited in urban areas that feed heat to district heating systems.) Surely, in the classic argument for cogeneration, this nuclear-generated heat could and should be put to use?

In some places is it. Russia, several East European countries, Switzerland and Sweden have all had nuclear-fuelled district heating schemes, and heat from nuclear power plants has also been sent to industrial sites in several countries. Apparently, the world’s first nuclear reactor, Calder Hall in Cumbria in the UK, sent heat to a neighbouring fuel reprocessing plant back in the 1950s and ‘60s.

But these are old stories – these applications are based on old nuclear power plants, many of which are now closed or facing decommissioning. Of more interest today are the experiments being planned in China and Finland to develop new – but crucially much smaller than previous – nuclear reactors that could be sited close to heat loads. In these days of heightened awareness of energy efficiency and of bringing a variety of ‘waste’ heat sources into use, these smaller plants could, in theory, feed urban district heating schemes or industrial processes again. 

China has been developing the concept of nuclear-fuelled district heating for some years and is now planning a 100 MW (heat) demonstration project based on a new, local small reactor design. In China, improving urban quality is the major motivation. Meanwhile, authorities in three Finnish cities are reported to be seriously investigating the potential for new-design small nuclear reactors to feed their extensive – and currently fossil and biomass-fuelled – district heating schemes.

There is much work to be done – particularly as completed small reactor designs are still some way off. Yet, if we are going to see a new generation of smaller nuclear reactors one day, then surely this must be considered. Nuclear plants are basically heat-generating machines, after all.

Steve Hodgson,
Contributing Editor, Decentralised Energy