How Digital Modeling of Materials Will Make Next Generation Nuclear Possible

A revolution is underway in the nuclear energy sector. For the first time in decades, the field is brimming with urgency, ambition, and capital. Buoyed by growing energy demands, geopolitical recalibration, and climate pressures, nuclear power is undergoing a renaissance, one that will be driven not just by next-generation reactor designs, but by the materials that make those designs possible.

From private fusion startups to advanced fission microreactors, a common barrier stands in the way of progress: materials. The materials that the industry has relied on for decades are not up to the task at hand. New materials are needed, ones that can withstand intense heat, neutron bombardment, corrosion, and mechanical stress, often simultaneously. The recently announced U.S.-UK nuclear materials testing collaboration underscores just how urgent and global this challenge has become. And with deployment timelines accelerating, the need is not just for better materials, but for them to be ready now.

This is where physics-based digital modeling and integrated computational materials engineering (ICME) become essential. These technologies allow us to simulate how new alloys will behave under reactor conditions before we commit to costly and time-consuming experimental programs. They help us test performance in environments that push the limits of what’s physically possible. And they make it feasible to design, optimize, and scale new materials faster than ever before.

A New Landscape, a New Set of Demands

The most advanced fusion reactors being built today, such as Commonwealth Fusion Systems’ SPARC tokamak (Figure 1), operate at conditions not previously encountered in industrial settings. Inside these devices, the plasma reaches temperatures hotter than the sun’s core. The surrounding components must manage gradients that shift from cryogenic to incandescent in inches. Meanwhile, powerful superconducting magnets generate intense electromagnetic fields to keep everything confined.

These operations require structural castings the size of small buildings, tungsten plates that face the plasma, and superconductors operating at the edge of absolute zero. Each of these components demands materials that can survive extremes of heat, radiation, stress, and corrosion.

On the fission side, modular reactor startups are building compact, transportable units that use molten salt or gas cooling instead of water. These designs promise increased safety and efficiency but also introduce unfamiliar chemical reactivity and corrosion challenges. Once again, materials are the make-or-break factor.

Modeling the Impossible

At QuesTek Innovations, we’ve seen these demands play out in real-time. Whether it’s improving the ductility of tungsten so it can be rolled into fusion-relevant geometries, modeling how neutrons damage materials over time, or helping manufacturers explore novel vanadium-based alloys, we’re working at the cutting edge of what’s known and what’s possible.

Vanadium is a perfect example. Long studied but rarely deployed, vanadium alloys show promise for structural use in nuclear applications due to their exceptional radiation resistance. But scaling them from lab samples to reactor components isn’t simple. Vanadium alloys are unfamiliar to most commercial producers, and their processing requires careful attention to melting, forging, and impurity control. Modeling helps us fill those knowledge gaps, predicting properties, guiding manufacturing parameters, and accelerating qualification.

These are not hypothetical problems. Commonwealth, Pacific Fusion, and other fast-scaling nuclear startups are securing billions in private investment. They are pushing the limits of materials performance, as well as timelines. They can’t afford multi-year iterative cycles of design, test, and revise. They need predictive insight.

Complementing Testing, Not Replacing It

It’s important to say—modeling isn’t about avoiding testing. It’s about making testing smarter. Experimental programs are essential for validating material performance, especially in safety-critical applications like nuclear. But physical testing alone is slow and expensive, particularly when it requires building specialized facilities or irradiating specimens over months or years. Modeling lets us isolate variables, screen candidate alloys, and anticipate failure before we commit to those programs.

In many cases, modeling is the only viable way to get early insight into extreme environments. High-fidelity simulations can project how a material will behave at elevated temperatures and under high neutron flux, even if no facility yet exists to recreate that exact scenario. This ability to “look around the corner” is invaluable for guiding investments and lowering the risk profile of research and development.

Physical testing remains indispensable. Yet, as nuclear programs—public and private—work to meet ambitious timelines, integrating digital and experimental methods will be essential. The success of future reactors will rely as much on the strategic development of advanced materials as on the designs themselves.

—Jason Sebastian is executive vice president of Market Operations at QuesTek Innovations LLC, a pioneering materials engineering firm that empowers innovators by resolving materials-based challenges.