Why the golden unlock with nuclear power will be mental

It’s a summer day in August 2017. Behind the quiet sand dunes near Petten, a village in the Netherlands where the North Sea is kept at bay, the only noise comes from a group of seagulls. They’re fighting over the remains of a lunch someone has left behind. Other than that, the place is deserted. You’d be surprised to find that some hold this as a historic place and a historic day.

Here in Petten, at the facility of the NRG (Nuclear Research & Consultancy Group), a project has just begun what could be a milestone in the development of nuclear power. As of this morning, the research reactor contains six lumps of salt, each the size of a die and carrying a few grains of thorium. It may not sound that spectacular. Yet thorium has been heralded as an improvement in nuclear technology, and could be the next step in the transition to a clean energy supply. Thorium is a weakly radioactive element, which is even more abundant in the Earth’s crust than uranium. A so-called molten salt reactor using thorium produces waste that’s relatively short-lived, ‘only’ 300 years or so. The reactor is supposed to be entirely safe thanks to features such as a plug of solidified salt, which melts automatically when the reactor gets too hot, for instance if the cooling pumps lose power. Once the sealing plug has melted, the salt flows into storage vessels underneath the reactor and the nuclear fission process stops. 

Put simply: since the fuel is already molten, nobody needs to worry about a meltdown. If the reactor overheats, things will be fine, not thanks to human intervention but to the laws of nature.

Over a cup of coffee in the canteen, Sander de Groot, a product developer at NRG, can’t stop talking about thorium. The first time he read about it must have been around 2006, he says. A molten salt reactor containing thorium had been running at the Oak Ridge National Laboratory in the 1960s. It worked. Everything that went on with the reactor was meticulously recorded at the time. For decades, these reports had been gathering dust in a filing cabinet. At the beginning of this century, a young employee of NASA rediscovered the reports, scanned them and made them available online. De Groot stumbled upon them a few years later.

Whenever De Groot talked about thorium with colleagues, they found it “too wild” and “speculative,” he says. A smile appears on his face. “Well, today, at last it’s happening.” A lot has changed since — and not just for Sander de Groot, who moved on in 2022 to co-found Thorizon, a start-up designed to accelerate developments in the use of thorium. First there were the number-crunchers, checking to see if such a reactor could operate without any problems. Then came the entrepreneurs, looking for investors to support their business cases. And, now, it’s time for the next step: fundamental research, financed with public money and carried out in a reactor owned by the European Union. The Netherlands is leading the way. Delft University of Technology is coordinating an international collaboration to develop the design of a thorium molten salt reactor.

“The potential is huge,” says De Groot. “In a molten salt reactor, thorium can be used so efficiently that it can be a safe and almost infinite source of energy.”

After decades of stagnation, a wave of innovation is sweeping through the nuclear industry. Thorium is one of many options for the future. Work is being done on fuels that can withstand every conceivable accident, and on reactors that can more easily cope with the erratic, weather-dependent power production of wind turbines and solar panels. Much of the focus is on small modular reactors (SMRs), for which components are produced in factories and assembled on site. Industry representatives say new nuclear plants are becoming more efficient, requiring less uranium and producing less waste. Or they are becoming safer, thanks to yet another layer of measures. Some designs are intended for sites near coastal cities, others for remote areas. Some use both the power and the heat released to produce hydrogen, which can be used in industry or as fuel for aircraft and container ships.

And then there’s nuclear fusion. In a fusion reactor, temperature and pressure are extremely high so atoms squeeze together like they do in stars, releasing an awful lot of energy. So far, nuclear fusion has always been something that exists only on the horizon. In 2021, a milestone was reached at the Oxfordshire-based Culham Centre for Fusion Energy where researchers managed to sustain fusion for five seconds, releasing 59 megajoules of energy, enough to boil a few dozen kettles of water. It’s also enough to get dozens of headlines published across the world.

All these stories feel like a breath of fresh air. Could the nuclear industry finally be changing? Is there room for new and bold ideas that give nuclear energy a future? Might it be, after its dark journey through Hiroshima and Chernobyl, on its way to an awakening?

In the emerging pro-nuclear movement, there’s plenty of discussion about the benefits and downsides of each new reactor design. There’s a catch to everything. In one design, the material would be prone to corrosion, while in another, disposal of fission products may become a concern. Breeder reactors could dispose of nuclear waste, but they might also be used for the production of weapons material.

With their technical disputes over the pros and cons of each reactor, proponents of nuclear power inadvertently reinforce the main point of their opponents: that today’s nuclear plants are flawed. ‘Advanced nuclear’, the generic term for all innovations, suggests that current nuclear plants are not advanced. It’s as if they’re obsolete and in need of serious adaptations.

And why is there so much focus on innovation, really? Nuclear plants have a pretty good track record. The problems with nuclear power have nothing to do with technology. The problems are between the ears.

Nuclear plants are distrusted, so now, with each innovation, they need to be made socially acceptable. Safer, because nuclear power is fraught with dangers. Flexible, because solar and wind should be prioritized. Smaller, because small is beautiful. But will all this innovation really make nuclear power better? Does anyone believe that a different type of reactor or fuel will make resistance disappear?