Engineering news
Small nuclear reactors based on current technology will be used commercially in the UK within the next ten years, an expert from the National Nuclear Laboratory has said.
Speaking at the Innovation in Energy conference at the Royal Academy of Engineering in London, Dr Fiona Rayment said that there were dozens of small modular reactors (SMR) in development around the world that would be suitable for use in the UK.
She said that the most likely designs to be used first will be based on the pressurised water technology used in current large reactors. There are dozens of SMRs being developed around the world by companies such as Nuscale, Gen4, Mitsubishi, Holtec, mPower, Westinghouse, General Atomics and the South African PBMR (Pebble Bed Modular Reactor) project.
Nuclear reactors are categorised as small if they have an electrical output of between 10MW and 300MW. They are suitable for use in remote locations as well as niche applications such as desalination plants and on barges.
SMRs size should mean their components are easy to supply and mass produce and civil works on site should also be reduced. They also enable economic advantages through being deployed in stages. Small nuclear reactors are already used in some marine applications such as submarines and Russian icebreaker ships.
However, Rayment said that a company was yet to fully produce and test a SMR yet, and that anticipated economic and safety benefits should not be relied upon.
“The furthest developed designs are at least 10 years away from commercial applications. The economics are all theoretical because this technology still is at a conceptual stage," Rayment said.
"There is no current SMR that has been fully designed in order for its economic model to be fully validated."
Modular reactors could be installed together in either single unit configurations or with several grouped together in series to form power stations with outputs comparable to today's large reactors. SMRs have advantageous safety features including underground siting, autonomous refuelling systems and natural circulation for cooling. However these features still need “a lot of R&D” to validate.
Rayment said: “Some of the modular systems are deemed to be safer because they are smaller. But put them together and you safety systems similar to larger reactors.
“It remains to be seen if the engineers enable the advantages to remain.”
She added that later reactors were likely to use alternative coolants such as molten salt, so that heat from the reactors could be better harnessed.
Interest in SMRs has increased recently, after government and industry figures met earlier in the year to discuss the UK nuclear supply chain's capabilities in this area and the publication of a report on the subject from the University of Lincoln's school of engineering.