Small Modular Reactors: a new nuclear concept

The costs of constructing new nuclear plants run into the billions. This is partly because they’re bespoke builds and few in number, which limits the opportunity to benefit from economies of scale. And that’s where the Rolls-Royce company Rolls-Royce SMR comes in. SMR stands for Small Modular Reactors. Their vision is for a fleet of nuclear reactors but on a smaller scale and made on a production line, keeping costs down. Within the last week or two, they’ve just submitted their proposal to the industry regulator for appraisal. Mark Salisbury, heads the company’s regulatory assessment team and talks to Chris about the plan...

Mark - I think our customers might feel a little hard done-by if we gave them the instructions and asked them to assemble it themselves. But in essence, that's what we are looking to do, maintain high quality products that we can roll out at a fast paced to help the country meet net zero, but still maintaining safety as our utmost priority.

Chris - When we say these are small reactors, how small is small? What could you power with one of these?

Mark - Physically in size for one of our SMRs, the site would be about the size of two football pitches, and that would provide enough electricity for about a million people over its 60 year lifetime.

Chris - And if one compares two football pitches for one of your units compared with say one of the current nuclear stations we have in the country at the moment, how do they compare size wise?

Mark - Again, on the physical size, it is roughly about five times the size, but the electrical output is much higher, able to power about three to 4 million homes. It's not so much that one is better than the other. We're going to need a mixture of everything to help us meet our net zero goals, but it's finding the right technology for the right situation and using them all together to achieve net zero.

Chris - Where will you put them?

Mark - We are looking at a number of sites, the first ones that are readily deployable will be on sites or next to sites with an existing nuclear power station. For the same reason that Simon mentioned about where we site nuclear power plants, places where people are used to them, we have the grid infrastructure ready, and they have the geology, geography and makeup that we are looking for. As we move out and hopefully expand the fleets of plants that we are looking to construct and that others are looking to construct we'll need to look at other sites. We'll be looking for sites that are close to areas of high energy demand, but have similar characteristics to sites that we see at the moment that have existing nuclear plants on them.

Chris - And are these pretty much the same technology we already have, or are these a brand new way of harnessing nuclear energy?

Mark - They're a bit of both really. The technology that they're based on is called a pressurized water reactor, and those have been in operation globally since 1957. It's a very well understood, very well refined, very mature technology that's been improved and optimized over the decades. The way that we are different is that we are shrinking that down and we are creating a product line. We will have factories that we'll be able to ship parts to sites and then install within a factory on the site itself. That will drastically speed up construction time and reduce costs.

Chris - Basically you've got a slew of factories around the place that are making the parts, where will those parts be sourced? And is this something that you can set up to make it sustainable? Will it be locally produced or are we gonna be buying bits from other countries?

Mark - That's a really good question. Some of the parts we will have to import, but what we are looking to do at Rolls Royce is also by shrinking the size of the technology, we're able to increase the market size for the supply chain in the UK. We're looking to build factories in the UK to build these plants. We're looking to create a fleet of reactors and create about 40,000 jobs by 2050. And we estimate that will generate about 52 billion pounds in economic benefit. We are very much looking to grow both our nuclear generating capacity in the UK, but also our manufacturing capability because otherwise we could end up trading one problem for another

Chris - People are still wary about nuclear, how safe are these and what safeguards are being put in place to make sure that people can sleep easy?

Mark - Nuclear plants are incredibly safe from a security and a safety perspective. We use a multilayered system of defenses or multiple barriers to help safety, and each of those has a redundant or a diverse means of achieving the same aim. If we need power to a site we might have offsite power. We might have diesel generators. We might have batteries and the same with our design of power stations. Nuclear plants rely on what's called passive safety. That's not necessarily requiring power or a pump to run to keep something cool. That's relying on natural forces like convection or gravity to keep a plant safe.

Chris - The other thing which does concern people very much is what we do with the waste.

Mark - Sure. It's a good question. I think it's important to put it in perspective that every process on earth creates waste and nuclear is no different. From over 80 years of nuclear science and technology and medicine research, industrial purposes, energy generation, and defense, we have generated nuclear waste in the UK and we will have to deal with it. The other thing to bear in mind is the size or the magnitude of that waste. High level waste, which accounts for about 95% of the radioactivity, the stock part, if we put that all together in the UK would cover an area only a quarter of the size of a football pitch. If we look to deploy a large fleet program in the UK for about 16 gigawatts, we'd only be adding about 10% to this existing stock pile. Now we know what to do with it. Nuclear waste is normally in the form of concrete or ceramic or metallic material and we box that up and confine it and store it. Unlike chemical waste or other types of waste, radioactive waste does decay in toxicity over time. We know what to do with it. Currently, it's stored at specific locations and the government is looking to build a facility to take these wastes and be able to store them whilst their radioactivity decays over time.

Chris - And if the regulators who are currently considering your proposals do give it the nod. What's the timeline for implementing this now?

Mark - We're looking around 2030 to be able to start rolling out our small module, the reactors, and once we get the factories up and running, we'll be able to roll them out in quick succession.