Doing away with diesel using small modular reactors

Deep decarbonization – it’s so easy to say, and yet it is going to be so difficult to achieve. Even speaking as an ardent champion for the use of nuclear technologies, the fact is there is no one big fix, because there is no one big source. Our greenhouse gas emissions are coming from an incredibly distributed, large number of point sources, from the rear end of cars to the front end of cattle.

Faced with that reality, it’s reasonable to try and break that challenge down into more tractable pieces, leading to such overwhelming focus on the decarbonization of electricity grids. Here, we can at least count and describe the sources, they are usually large, and technology substitutes are readily available. In a world where we are seeking the low-hanging fruit, cleaning up our existing grids is as close to a technological watermelon as we will ever find.

The challenge surrounding off-grid power

As far as decarbonization solutions, one of the challenges hanging out there looking for a solution is off-grid power – electrical power that is being delivered away from major grids, be it in small settlements, islands, or remote mining and industrial operations.

The figures in question are, perhaps deceptively, large. The International Renewable Energy Agency (2015) estimated that “there are ca. 400 gigawatts (GW) of diesel capacity (>0.5 megawatts (MW)) in operation, either in the form of industrial facilities and mines operating remotely, as back-up units where electricity supply is unreliable or as community mini-grids.”

Uptake of off-grid power in the form of renewable energy systems has been growing strong, largely to meet the new demand for swift delivery of partial electrification. But the response to the larger challenge remains only partially answered with renewable technologies. IRENA estimates that some 50-250 GW of the installed total could be “hybridized” with renewables, meaning a partial displacement of fossil fuels for a part of the sector. That leaves a lot of other parts.

Paradigm shift

We might be able to do better in the near future with purpose-designed small modular nuclear reactors (SMRs). These might supplement or complement renewable technologies in a blended solution, or, in many cases, provide nearly the entire need in a reliable, long-lived and affordable package.

One sector which is likely to lead the uptake is mining and mineral processing. For this sector, the power requirements at single sites can be high, as is the requirement for stable, reliable power. The necessary investments in people and facilities for such operations makes reliable power essential. In many locations, particularly in the far northern hemisphere, the location itself diminishes the plausible role of potential low-cost contributions from solar photo-voltaic systems. In many more locations, the environmental conditions will also challenge the lifetime performance of renewable systems with their exposure to extreme weather.

Developments in SMR technologies are already demonstrating a zero-carbon solution. These types of small reactors offer a paradigm-shifting answer to ‘off-grid’ – namely that there need be no compromise in supply, price, reliability or sustainability. Last year, the world saw first power produced from the reactor on board of Rosatom’s barge Akademik Lomonosov. The two 35 MWe reactors on board will provide reliable power and heat capacity of 50 Gcal per hour for the next 60 years to Chukotka, a major mining region in northern Russia. It is easy to foresee more such portable, ocean going clean power plants becoming the solution of choice for island grids dependent on external supplies of costly and polluting diesel.

Another remarkable development is the 1.5 MWe Aurora Powerhouse from Oklo, currently being licensed in the United States. Once granted, the Powerhouse could save up to 1 million tons of CO2 compared to diesel generated power. A fast-breeder reactor – with a large ratio of fuel-to-power output, and less waste with lower toxicity – the facility could operate with exceptional reliability for an uninterrupted 20 years. In the reality of operations, that might turn out to be much longer (according to my information). A dry-cooled design, it would have zero-water consumption and might even provide water security through powering desalination and treatment. Mining operations and remote communities can again be expected to be early adopters of this technology, which is presently estimated to cost US$10 million for the first plant.

Nuclear for low-impact mining

I have been in sustainability long enough to know that there can be an almost reflexive recoil to the idea of lowering the impact of mining – as though the real goal ought to be to shut it down, and reliable clean power makes that harder to argue! I speak from experience of a younger self, and we need to set these misconceptions aside. The challenges of transitioning to a decarbonized energy system, whatever the portfolio of technologies, will demand extraordinary investments in new infrastructure, be it power plants, panels or power lines. At the beginning of that journey are minerals taken from the ground, which might also find their way into green technologies such as batteries for electric vehicles – so we had better get good at it, and we had better make it as clean and low impact as possible.

When the reach provided by nuclear technologies makes it easier to exploit fossil fuels, then we really do face quandaries. I argue that we must fight through that challenge, not run from it. We will stop mining fossil fuels – coal, oil and gas – the moment the alternatives are better, cheaper, plentiful and reliable. Advanced nuclear technologies offer a path to that outcome, providing our power, charging our cars, making plentiful hydrogen and synthetic fuels that are simply cleaner, cheaper, and better than fossil oil. Advanced SMRs will likely prove the most transformative technology in the sustainability tool kit, cutting emissions and bringing reliable energy to where it is needed.

In just a few years, deep decarbonization might become a whole lot more plausible thanks to these technological advances. More sustainable, decarbonized mining operations would be a very good place to start.