Trying to build the future with yesterday’s toolbox - the materials bottle neck preventing a nuclear renaissance.

As someone whose always had a keen interest in ‘nuclear anything’, since I first saw Homer Simpson stumble to his Springfield nuclear plant workplace, I’ve always been in awe of the potential and pure might the technology holds. To my wide-eyed, young science-enthusiast self, nuclear energy seemed limitless and almost magical in a sense. However, as a more ‘seasoned’ researcher whose swapped out cartoons (kind of…sort of 👀) for metallurgy lectures, the true realities of why nuclear power hasn’t simply taken over the global scene have become much more apparent. Over the years I’ve come to learn that the real chokepoint in the nuclear renaissance lies deeply rooted in materials science.

🥜Nuclear power in a nutshell

Before we dive into the nitty gritty, let me quickly state what nuclear power is and why there’s so much ‘hype’ (and lets be real – ‘hate’) surrounding it.

In a nutshell nuclear power is essentially the energy harvested when an atom is split in two by a process called nuclear fission. Inside nuclear reactors, heavy atoms such as uranium are broken apart upon the impact of a high energy neutron. This results in pieces of the uranium fuel and several loose neutrons which go on to do the same and produce a chain reaction. The formation of these ‘fission fragments’ release masses of thermal energy that the reactor uses to heat water, forming pressurised steam, which in turn moves turbines and poof, we get electricity 🎉. In this case the electrical energy produced is clean, zero-carbon and supposedly sustainable (we can address the claim another time 🙄).  

Unlike many other conventional renewable methods such as solar and wind power, it can be produced 24/7 and isn’t dependent on the weather. Because of this, nuclear power is much more readily available and has the stability to meet our ever-growing energy demands, which helps to reduce our reliance on carbon-based methods when the renewable sources can’t cope.

💸🏃Nuclear’s financial momentum

There has been a growing push for nuclear power development since it first appeared back in the 1950s. However, with growing concerns of climate change, unstable grids and exponentially growing electricity demands the pressure is really on to make the technology more mainstream. As these tensions amount, the UK legally pledged to reduce all carbon emission by 2050, by increasing the nuclear energy capacity from its current 6Gw to 24 Gw, accounting for about a quarter of the region’s electricity demands. Countries such as France, Canada, and Japan, are all following in similar suits.  

As we all know, when governments signal, the markets respond. With these legislation orders, the global nuclear market has been booming. With a value of USD 36.29 billion in 2024 and CAGR of 3.1%, the market is on a steady trajectory to amount to USD 46.33 billion by 2032.  Governments offering subsidies, tax credits, and regulatory reform, have made private sectors also eager to invest. Key areas tend to be large scale reactors, nuclear supply chains, waste management and decommissioning, Advanced Reactor Technologies and most importantly small modular reactors (SMRs). we will definitely discuss the beauties of SMR in the future.

💣So what’s the issue?

This also sound honky-dory, but it’s just not that simple. Throwing money at the projects and gaining public approval just aren’t going to cut it. If we want to create a stable nuclear power industry on a global scale, we must tackle a more fundamental challenge: the nuclear material bottle neck.

So here’s the crux of it… nuclear reactors are some of the most hostile working environments imaginable. We’re talking temperatures up to 950°C, relentless neutron radiation that knocks atoms out of place like bowling pins, corrosive coolants like liquid sodium or molten salts, and the expectation that materials will survive this for 40 to 60 years. I don’t know about you, but I can’t think of many materials that are up for that.

Zirconium alloys for example have been our go-to choice for fuel cladding in traditional nuclear reactors for some time; they’re dependable and familiar. But in newer, more advanced reactors, they start to struggle, literally buckling under the high pressures. Other materials such ferritic and austenitic steels, graphite, and ceramics all have their advantages, but honestly none quite that right. They definitely have their vulnerabilities: radiation swelling, embrittlement, corrosion, thermal creep… the list goes on.

Even when we try to find fancier alternatives —like ODS steels or silicon carbide composites—we still can’t evade the issues. Can we make them in large enough quantities? Will safety regulators approve them? Will we certify them in time? Usually, the answer is nope.

Fuel is also a fat problem. Many new reactor types need HALEU (High-Assay Low-Enriched Uranium), but there's not much of it around. And if we try advanced fuels like TRISO or metal-based options, we’ll also need new materials to hold and protect them safely.

To add the headache, many of the critical elements we rely on—like helium, beryllium, molybdenum, and niobium—are rare, expensive, or come from politically unstable regions. I know its really not looking good 😢.

👩‍🔬My ‘expert’ opinion

I know, I’m not a nuclear scientist but where I sit a as a materials scientist, the biggest hurdle to nuclear power isn’t just the reactor tech—it’s the materials we rely on to make it all work safely and consistently. Advanced reactors and SMRs get a lot of hype, and sure, they’re promising. But what frustrates me most is the lack of conversation about how much we’re still limited by the physical stuff we build them from. If nuclear is going to truly make a comeback, we need to stop treating it like a purely design or policy issue and start acknowledging the materials reality.

SMRs, for example, definitely offer some hope. Because they’re smaller, they don’t need anywhere near as much material. Their operating conditions also tend to be a bit more tolerable, since they operate at lower temperatures and use less aggressive coolants. Hence, we can generally use materials from our current inventories, instead of having to concoct some brand-new exotic alloy in our labs. These faster build times and fewer uncertainties are definitely a major plus in my books. But—and here comes my scientific sceptisim—SMRs aren’t a silver bullet. They still face huge materials challenges. Fuel cladding still needs to survive the intense radiation and heat years on end, and packing everything into a smaller space might even increase some stresses on materials. Plus, many SMRs want to run on HALEU fuel, and the supply of that is painfully limited right now. So, the materials problem isn’t going away; it’s just re-appearing in another form.

The truth is, the materials issue is wrapped up with economics, regulation, and supply chains. Its easy for me to sit in a lab and simply say ‘just invent the perfect new alloy’. However, even if you do so, they still must go to the real world. So, you’re literally looking at decades before it’s certified and trusted for reactor use. In the meantime, the world’s screaming for clean energy now.

On one hand I do sometimes feel we have enough decent materials to start building—but maybe not quite enough to reach the next level of efficiency or safety we really need for the rising demands. We seem to be stuck between a rock and a hard place: move quickly and risk mistakes or move slowly and risk falling behind…neither option feels great.

I’m cautiously optimistic, though. We’re pushing hard in the research community. Asing AI to speed up materials discovery, 3D printing to make complex parts, and better testing methods to cut down development time are all tipping the scales in our favour. But at the end of the day, you can’t shortcut the harsh realities of radiation damage or corrosion chemistry – the losses are just too great to role the dice on.

The materials bottleneck is real, and it’s tough—but it’s also the gateway to everything we want nuclear to be: safer, cleaner, and more reliable. I truly believe we can break through it. It’s going to take time, serious collaboration, and a lot of persistence.

Thanks for reading.

Amina Hussain