Welcome to Nuclear Update.

Fusion has been 20 years away for the last 70 years. Then 2025 happened, and suddenly every billionaire, national lab, regulator, and AI data center planner started acting like we might actually plug a star into the grid.

This week, I am writing to you from Geneva, Switzerland, where I took some precious time off and finally checked something off my nerd bucket list. I visited CERN and the Large Hadron Collider, the biggest scientific machine ever built and arguably the most ambitious attempt humanity has made to understand the universe.

That really sets the mood for a fusion deep dive. If there is any place on Earth where smashing tiny particles together is normal, it is here.

But before we turn Earth into a very polite, highly regulated imitation of a star, let us see how well you know the biggest machine humans have ever made:

Last week, I asked: In the periodic table, what does an element’s atomic number represent?

You said: 

⬜️⬜️⬜️⬜️⬜️⬜️ The order in which the element was discovered (4%)

🟩🟩🟩🟩🟩🟩 The number of protons in the nucleus (79%)

⬜️⬜️⬜️⬜️⬜️⬜️ How common the element is in Earth’s crust (3%)

🟨⬜️⬜️⬜️⬜️⬜️ The number of electrons it usually has when forming bonds (14%)

Now, let’s dive into the good stuff!💥

⚛️ Why Fusion Matters Now More Than Ever

Fusion is the energy source of stars. It is clean, it produces virtually no long lived waste, it cannot melt down, and it uses fuel you can literally skim from seawater. That has always been the pitch.

The problem has always been the same. It is really hard.

To get fusion, you need to heat hydrogen isotopes to about 100,000,000 (one hundred million) degrees Celsius, confine them long enough for them to smash together, and do it in a machine that does not destroy itself in the process.

For decades, fusion progress moved in inches. Then something shifted. AI supercomputing exploded. Data center build plans went vertical. Energy security moved from policy paper to national priority. Electricity demand curves bent upward like a hockey stick. And governments suddenly decided they did not want to be left behind.

In June 2025 the United Kingdom committed £2.5 billion to its STEP fusion plant. Later, in October 2025, Germany approved more than €2 billion in federal backing to build a full fusion ecosystem. Then in November 2025, the United States launched the Genesis Mission, tying AI, national competitiveness, and next generation energy systems together. Under this mission, the Department of Energy is mobilizing more than 40,000 scientists to accelerate breakthroughs at the intersection of fusion, AI, and data centers.

Fusion did not get easier, but the world has suddenly got more motivated.

Add in a wave of private funding, real experiments hitting fusion gain, new materials research, fast prototyping, and national programs betting on fusion’s long term role, and the conversation stopped being theoretical.

Fusion is no longer “someday”. It is officially “let’s make it work ASAP”.

🔥 Fusion vs Fission: The TLDR for Normal People

If fission is a neat accountant splitting heavy atoms to keep the books balanced, fusion is the chaotic rock star of nuclear physics, smashing light atoms together with enough force to light up your toaster.

Both release enormous amounts of energy, but they do it in opposite ways.

Fission takes something big and breaks it apart. We split uranium or plutonium, get a lot of heat, and yes, create some long lived waste. The upside is that we have mastered this process for more than half a century, and almost 500 commercial reactors rely on it every day to keep grids running.

Fusion, on the other hand, takes the smallest building blocks in the universe and slams them together until they merge. When deuterium and tritium fuse, they create helium and a burst of energy (with almost no high level waste).

The fuel is abundant, the reaction cannot run away, and the safety profile is incredibly attractive. The challenge is simply achieving the extreme conditions needed for fusion to happen at all.

And here is a fun twist that most people do not know. Even the futuristic fusion reactors of the 2040s and 2050s will still be, at their core, glorified steam kettles. Whether the heat comes from splitting atoms or fusing them, you still need to transfer it into water, make steam, spin a turbine, and generate electricity. Stars might run on plasma, but power grids run on steam.

🔄 How You Actually (Try to) Make a Star

Fusion is not one technology. It is an entire zoo of ideas, each trying to create the conditions inside a star without melting the building it sits in.

Let us explore the big three.

Tokamaks: The Donuts That Ate the Decade

Tokamaks are the celebrities of the fusion world, the giant magnetic donuts that try to trap a sun inside a steel ring.

The idea is simple in theory: heat hydrogen fuel until it becomes plasma, confine it in a swirling, perfectly balanced magnetic field, squeeze it hard enough for fusion to begin, and then hope the plasma behaves itself long enough to extract useful energy.

These machines dominate almost every fusion conversation for a reason. They are the most studied design, backed by decades of experimental data from facilities all over the world. Engineers understand how they scale, how they fail, and what must be improved, which makes them the closest thing fusion has to a commercial blueprint.

When policymakers talk about fusion timelines, when investors ask who is furthest along, when national labs draw roadmaps, they are almost always thinking in tokamak terms.

Tokamaks have their challenges. Plasma can wobble. Coils can overheat. Materials can degrade under intense neutron bombardment. Tritium handling is also a bottleneck. Still, they remain the front runner, the design most likely to cross the finish line first.

Projects include ITER in France, SPARC in the United States, K-DEMO in South Korea, and STEP in the United Kingdom.

Stellarators: The Pretzels From Another Dimension

If tokamaks are the sleek, symmetrical donuts of fusion, stellarators are the pretzels from another dimension. Their magnetic coils twist and bend in ways that make engineers shake their heads and whisper quiet prayers.

But that bizarre geometry is exactly the point.

A stellarator tries to build plasma stability into the machine itself. Instead of forcing plasma into a neat circular orbit and constantly correcting it, like the tokamak, a stellarator sculpts the magnetic field so the plasma naturally flows along those curves. It is like designing the racetrack so the car stays on course instead of relying on constant steering corrections.

The result is a reactor that is inherently more stable. Stellarators do not suffer from the same violent plasma disruptions that keep tokamak engineers awake at night. They need far less active feedback control, they can operate in steady state for long periods, and they offer a calmer, more predictable environment for fusion reactions to unfold.

The tradeoff is that they are incredibly hard to build. Designing the magnetic coils requires supercomputers. Manufacturing them requires precision on a scale that would make a Swiss watchmaker sweat. Every twisted segment has to align perfectly with every other one, or the whole magnetic geometry falls apart.

Germany’s Wendelstein 7 X proved that this complexity might be worth it. It produced some of the best plasma confinement ever measured, validating that these strange geometries could outperform their donut shaped cousins.

Stellarators are not perfect, but they are beautiful, both in physics and in potential.

Inertial Confinement Fusion: The Laser Side Quest

Instead of magnetic fields, inertial confinement fusion uses lasers. Lots of lasers. The National Ignition Facility (NIF) focuses almost 200 beams onto a tiny fuel pellet, blasting it so violently that the implosion triggers fusion.

In 2022 and 2023, NIF achieved fusion gain, meaning the fusion reaction produced more energy than the energy delivered to the fuel. It was one of the most important scientific milestones in fusion history.

There is a catch. The lasers themselves consume far more energy than the pellet receives. And the system must repeat this process 10 times per second for useful power production. We are a long way from that.

Still, it proved something profound. Fusion breakeven is real. It is not theoretical. The physics works.

The Fusion Frontrunners

Helion: Pulsed Fusion and the Microsoft Bet

If lasers are the dramatic side quest and tokamaks are the main character, Helion is the disruptive indie film that suddenly gets a major studio behind it.

Helion uses a pulsed magneto inertial approach. Instead of holding plasma in a continuous loop, it accelerates plasma from both ends of the machine and collides the streams in a central chamber. At peak compression, fusion occurs, and the expanding plasma pushes back on the magnetic fields like a piston. Helion captures some of that energy electromagnetically, which helps power the next pulse.

This architecture is smaller, simpler, and built for rapid prototyping. Helion is already on its seventh machine, each one built to hit a targeted physics milestone. No megaproject, no decade long civil works plan, just fast iteration.

Microsoft signed a power purchase agreement to buy electricity from Helion’s first commercial system. The timeline is ambitious, they’re supposed to supply electricity by 2028, but the signal is clear. Big Tech is not waiting for fusion to arrive. It is placing bets on which pathway might become real first.

Helion may not be the consensus pick among traditional fusion physicists, but it is the company most aggressively trying to skip ahead.

Commonwealth Fusion Systems: HTS Magnets and the Google Bet

Commonwealth Fusion Systems, or CFS, is taking the opposite approach. Rather than reinventing fusion, they are reinventing the magnet.

CFS builds compact tokamaks using high temperature superconducting magnets, which can generate far stronger magnetic fields than conventional superconductors. Stronger fields mean better plasma confinement in a smaller machine. This allows a reactor with the physics of a tokamak but the footprint of a normal power plant.

Their ARC reactor design represents a technological leap, one that shrinks the tokamak concept into a commercially viable package.

Google stepped in as both an investor and a customer, signing an agreement to buy 200 MW from CFS’s first commercial plant in Virginia.

CFS has the most credible path to commercial fusion built on known physics. Its approach is evolutionary rather than revolutionary, and its partnership with Google gives it both capital and compute power to accelerate development.

If Helion is attempting the shortcut, CFS is attempting the high performance upgrade to a proven design.

The Startup Wildcards

Beyond the main contenders, a wave of smaller companies are pushing alternative ideas. Zap Energy is betting on a modernized z pinch. First Light is compressing fuel targets with high velocity projectiles. Tokamak Energy is pursuing spherical tokamaks that shrink the geometry further. Each approach attempts to strip away complexity or reduce cost, betting that a simpler machine will win the race to commercial power.

These designs may not hit the grid first, but they are forcing the industry to rethink what a fusion machine can look like.

🧱 The Bottlenecks People Do Not Want to Talk About

Fusion hype is fun, but fusion engineering is unforgiving. Here are some of the obstacles:

Tritium scarcity - Tritium is rare, expensive, and global supply is tiny. Breeding blankets solve this, but require flawless materials.

Neutron damage - Fusion neutrons are extremely energetic. They attack reactor walls, degrade metals, and reduce component life.

Blanket design - Blankets extract heat, generate tritium, and protect hardware. These must perform perfectly.

Repetition rate - Laser systems must operate ten times per second. Pulsed systems must recover energy efficiently.

Economics - A plant is only useful if it delivers cheap electricity. Fusion will not compete with fission in the early decades. It will compete with gas peakers, hydrogen production, industrial heat, and data center backup.

Fusion does not need miracles. It needs metallurgy, manufacturing, and extremely patient investors.

🕒 So When Can Fusion Actually Hit the Grid

Here is the realistic assessment:

Demonstration machines: Late 2030s

Early commercial pilots: 2040s

Meaningful market presence: 2050s

Cost competitive fleets: Second half of the century

Fusion will not replace fission. It complements it. Uranium demand does not change for decades. Fusion only strengthens the case for nuclear literacy, supply chains, and regulatory modernization.

📈 Tracking the Future of Fusion

Fusion may be the endgame, but the investable opportunities sit in the ecosystem being built around it. No fusion company is publicly listed today, yet the technologies, materials, and fuel cycles that fusion depends on are already reshaping the nuclear sector.

At Nuclear Update Premium, we go beyond the headlines and focus on what actually matters for investors. We track how fusion momentum affects uranium demand, enrichment capacity, tritium production, advanced materials, and the next generation of reactors that will bridge the gap between fission and fusion.

Inside Premium, you will get:

✅ Weekly Uranium and Macro updates
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If you believe in nuclear and want a portfolio positioned for the entire cycle, from today’s reactors to tomorrow’s fusion-inspired systems, this is where the signal is.

We are building the cheat sheet for the nuclear renaissance. Come steal our notes.

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DISCLAIMER: None of this is financial advice. This newsletter is strictly educational and is not investment advice or a solicitation to buy or sell any assets or to make any financial decisions. Please be careful and do your own research