Bus-sized nuclear reactors could replace large-scale plants

The so-called small modular reactors (SMR) are currently being developed by companies including Rolls-Royce and experts believe that within the next decade, the technology could be ready for commercial use.

"The real promise of SMRs is their modularisation,” Anurag Gupta, director and global lead for power infrastructure at consultancy KPMG told Reuters. “You can assemble them in a factory with an explicable design, meaning consistent standards and predicable costs and delivery timescale." 

The technology’s proponents envision the nuclear units, each capable of producing about a tenth of the energy of large-scale projects such as Hinkley, could be transported from factories on trucks and barges. The experts estimate it would take about six to 12 months to have the unit up and running once it reaches its destination.

"From a technical perspective, there is no reason why you wouldn't be able to make a smaller version of an already commercially viable nuclear technology such as PWR (pressurised water reactor)," said Mike Tynan, director of the UK's Nuclear Advanced Manufacturing Research Centre (NAMRC).

PWR technology is one of the most common systems used in existing nuclear plants to harness heat created by the splitting of uranium atoms to boil water to power electricity-producing turbines.

Several companies around the world are currently trying to downsize the systems. US NuScale is developing 50-megawatt units, each around 20 metres tall, less than three metres wide and about the length of two buses. The company believes that it could see its first SMRs generating electricity in the UK by 2026 if it obtains all necessary regulatory approvals.

UK-headquartered Rolls-Royce, which has experience with making PWR components for nuclear submarines, is part of a consortium developing a 220 MW SMR unit which could be doubled for a larger-scale project.

"One of the advantages of the SMRs is that they cost a lot less (than large nuclear plants), and it is an easier case to present to private investors," said Rolls-Royce Chief Scientific Officer Paul Stein, adding that the first 440 MW power plant would cost around £1.75bn but costs would likely drop once production is scaled up.

According to a study by the UK National Nuclear Laboratory, SMRs in the UK could generate up to 7 gigawatts of power by 2035. For comparison, the controversial Hinkley Point project is designed to provide about 3,2 gigawatt, which would cover approximately 7 per cent of the UK’s demand.

Hinkley Point, a joint venture between French energy giant EDF and China General Nuclear Power Group, was originally expected to start supplying power by 2023. The project’s future is, however, now uncertain as the UK government delayed its final decision over its support for the development until early autumn.

For the UK, investing into new energy infrastructure is paramount. Almost half of the country’s generation capacity is expected to close by 2030, as older, large nuclear plants come to the end of their operational lives and coal plants shut as part of the country's efforts to meet its climate goals.

The Hinkley Point project has been heavily opposed by environmental campaigners who would prefer the country to invest more into renewable energy generation.

However, some analysts point to the problem of renewable energy intermittency and the current lack of sufficient battery storage technology that would accumulate the electricity at times of generation surplus for later use.

"Working alongside renewables, nuclear provides the reliable low carbon energy required to balance variable wind and solar generation," said Tom Greatrex, chief executive of the Nuclear Industry Association.

All nuclear power projects need approval from Britain's Office for Nuclear Regulation (ONR), and its Generic Design Assessment (GDA), which tests the safety and design of new reactors and can take around four years to complete for large plants.
 
A spokeswoman for the ONR said as the plans are at an early stage, it does not yet know how long the GDA process would take for SMRs.
 
Nuclear power plants in Britain can also only be built on sites licensed by the government, and the first SMRs could be set up at existing nuclear plant sites or at licensed sites where older plants are being decommissioned.  
 
Earlier this year, the UK has committed £250m to SMR research and development. The funding is available through a competition. NuScale, Rolls Royce and Toshiba Corp's Westinghouse were among 33 companies the government has identified as eligible for the competition.