Small modular nuclear reactors with steel at their core could offer a more cost-effective, dependable and scalable method of power generation than traditional power plants

For many, the sheer size of a nuclear power station is a symbol in itself. These are colossal engineering structures so expensive they require government financing, combined with lengthy setup times and tricky maintenance schedules. But what if there was a different way to provide nuclear energy?

NuScale’s small modular reactor (SMR) project aims to do just that. It’s a way that’s cheaper, more reliable, and with higher potential output than traditional reactors, and a scalable capacity that ranges from small organisations to entire cities.

In conjunction with engineering giant Rolls-Royce and nuclear steel experts Sheffield Forgemasters Ltd, it’s produced a portable nuclear reactor so small that it can fit on the back of a single lorry. Coming in at 16m high, it may look pint-sized, but each has an output of 50 megawatt electric (MWe) – stack up to 12 of them and they can pump out 600MWe: the equivalent of 150 onshore wind turbines.

“Steel is a material used throughout the nuclear industry due to its inherent strength, durability and other metallurgical properties”

Opening up the nuclear market

It’s the modular aspect of NuScale’s project that sets it apart from larger, more complex nuclear power plants. Rolls-Royce patented the stackable design for the SMRs, which will open up the nuclear market to smaller organisations who are interested in trying nuclear; scaling up as their nuclear needs grow.

This flexibility, coupled with the fact they’re prefabricated offsite and can be delivered by rail or road for installation pretty much out of the box, means they’re perfect for off-grid, remote areas, such as natural disaster zones. Clients requesting a green energy-mix can also combine the SMRs with renewables.

Unlike traditional nuclear power plants, the SMR doesn’t require pumps, motors or valves. Using the movement of natural water circulation, the system employs a convection process to push up and heat a steady stream of water as it moves over the reactor’s core.

An illustration showing a NuScale modular reactor ready for road transport

Reliability and ease of maintenance

Less convoluted systems mean off-the-shelf components can be used, as well as a hard-wearing steel reactor head for easy maintenance.“Steel is a material used throughout the nuclear industry due to its inherent strength, durability and other metallurgical properties,” says Tom Mundy, Chief Commercial Officer and Managing Director (UK & Europe) at NuScale.

The steel reactor head and its manufacturer were chosen due to the reliability of both the material and Sheffield Forgemasters Ltd. The forge has been successfully developing steel reactor heads for nuclear power since the 1950s. “To achieve the benefits of repetitive off-site factory fabrication of our 50MWe power modules, including our steel reactor heads, it is important that the materials we use, such as steel, be proven and approved for use in nuclear applications,” says Mundy.

A question of safety

The SMRs boast a rapid set-up period of only three years. So how safe really are these plug-in-and-play reactors? After all, we are dealing with a volatile nuclear power source rather than flat-pack furniture. The answer is that maintenance is much more efficient thanks to its modular design, as one module can be serviced while the others continue to function.

What’s more, the technology sits inside a seismic category one shell structure designed to withstand the effects of aircraft impact, environmental conditions and natural phenomena. It also features NuScale’s Triple Crown for Nuclear Safety™, which means it can safely shut itself down and self-cool indefinitely during crisis without the need for extra power, additional water or human operation.

NuScale’s next step is to receive approval from the Nuclear Regulatory Commission, a 40-month process that began at the end of 2016. They’ve already secured their first client ­– the Utah Associated Municipal Power Systems. Coming in cheaper, safer and quicker to build than traditional plants and with a much smaller environmental footprint than other ‘clean’ energy sources, SMRs could represent the real future of nuclear.


Images: iStock, NuScale