When a company with an iconic brand like Rolls Royce claims to have the ‘answer’ to the clean energy future, you are inclined to give them a hearing. And so it was with the launch of Rolls Royce Small Modular Reactor (SMR) nuclear technology. In conjunction with partners including US-based Exelon (one of the largest nuclear plant operators in the world), and the Qatar Investment Authority, Rolls Royce SMR proposes a major shift in the nature of nuclear power generation.
Large, traditional nuclear power plants typically have a capacity around 2000 MW, with the largest up to 7000 MW. In comparison, Rolls Royce’s SMR will have a maximum capacity of 470 MW. This capacity limit is determined by the maximum reactor vessel size (4 meters in diameter) which can be transported from factory to site by road.
Factory assembly is the key claimed benefit of Rolls Royce SMRs. All components are produced in a factory and then transported to site, where they are assembled in the fashion of a Lego set. This allows high levels of quality control and rigorous testing of components in a reproducible environment. It minimises complex construction and fabrication work on site. It also means it is scalable, with greater manufacturing throughput increasing productivity and cost competitiveness, with the smaller size components, such as steam turbines, being standardized off-the-shelf products.
The footprint of a 470 MW SMR is around two football fields. The idea is that a temporary construction shed (a re-usable ‘site factory’) is built over the site so that all work can then be undertaken inside. This results in simpler crane solutions, and progress independent of external weather conditions, even at night, to reduce risk and weather delays, and enhance site productivity. A four year construction period is anticipated. Many conventional nuclear plants have taken up to a decade or more to construct.
The nuclear technology itself uses proven pressurized water reactor technology. The life of the plant is expected to be 60 years. Failsafe features are automatic and are self-activating based on heat, pressure or gravity. Waste from the facility is designed to be stored permanently on site. The first target SMR sites for Rolls Royce are existing decommissioned nuclear plants.
Rolls Royce SMR anticipate the first SMR unit being delivered in 2031 in the UK. By that time they aim to have their factory set up to produce two units per year (940 MW per year). Increasing demand would be met by building more factories.
They estimate the capital cost to be around USD2.2billion with a claimed levelized cost of electricity of around USD60 (GBP50) per MWh which is less than half of traditional nuclear plants, and competitive with renewables when you take firming costs into account.
To put these words into pictures you can watch this brief and slick promotional video from Rolls Royce.
So what should we make of all these claims? First, it is important that with the first unit coming into production no earlier than 2031, the investment in renewable energy sources, mainly wind and solar, must continue and accelerate.
We must also consider whether distributing nuclear material widely around the countryside is a wise long term idea. Further, it’s worth being sceptical about whether the factory-built modular approach will really deliver the claimed economic benefits given the loss of economy-of-scale inherent in a smaller reactor.
Nevertheless, my conclusion is that the SMR may find a useful niche in countries which already have nuclear capability and a willing populace. Optimistically, its timing means that it could gain traction and critical mass just when renewables approach their sweet spot of capacity, perhaps toward 90% of total demand. The last 10% can be tricky and expensive.
Conversely that means that the SMR is unlikely to be viable in non-nuclear countries and in places where geography gifts renewables a very significant advantage (e.g. Australia).
In summary, its worth being open to the idea of SMRs in the right places as one of a portfolio of future tools to get to the global zero emissions goal. But only if their economics and safety can be adequately demonstrated, and we won’t know that for at least a decade.
The writer is a co-author of Court of the Grandchildren, a novel set in 2050s America.
Image by Harisankar Sahoo from Pixabay
