Exclusive: Q&A with Pacific Fusion CTO Keith LeChien

Neutron Bytes asked Pacific Fusion to bring readers up to date on its development plans to produce a working commercial fusion power plant. In response to emailed questions, Keith LeChien, the co-founder and Chief Technology Officer (CTO) of Pacific Fusion, responded with the answers.

Background

In October 2024 Pacific Fusion, a fusion development company based in Fremont, CA, previously unknown operating in “stealth mode,” rocketed to the forefront of attention in the fusion industry startup scene by scoring $900 million in Series A funding from an “A List” of high-tech investors.

The firm secured more than $900 million in investor commitments. Hemant Taneja of General Catalyst led the round. Alongside General Catalyst, a mix of institutional VCs and individual company builders have participated in the funding round.

The company said in a blog post its funding will come in stages, based on the company meeting certain milestones. A short list of topical areas where the company is expected to set the milestones include; fuel, materials, plasma temperature, modeling of the system, and safety, among others. Funding will be unlocked in stages as the company meets its pre-defined milestones.

The firm’s immediate goal is net facility gain. The funding will be used to build a high-gain pulsed magnetic fusion driver to achieve ‘net facility gain’ (more fusion energy output than all stored energy input.

Q&A with Pacific Fusion

1. What is unique about Pacific Fusion’s technology, and why does it create technical and cost advantages for utilities?

Pacific Fusion is pursuing pulser-driven inertial fusion. Our system uses fast, high-current electrical pulses to compress small deuterium-tritium fuel targets to fusion conditions.

Our fusion system is modular and designed for manufacturing from the start. Instead of building a one-off facility designed for research, we are building a modular system made up of components that can be manufactured, tested, serviced, and replaced like industrial equipment. That matters as the practical basis for a power plant because the long-term value of fusion depends not only on achieving net energy, but on building power plants that are affordable, reliable, maintainable, and deployable at scale.

2. What are the key technical milestones relative to the goal of time to market by 2030

Our pulser-driven inertial fusion system works by charging pulser modules with electricity from the grid, then discharging them in tightly synchronized, 100-nanosecond pulses. That current creates a powerful magnetic field that squeezes a small fuel target hard enough to create fusion and release energy as heat.

Key milestones on the path to net facility gain by 2030 include: 

• Validate that the building blocks of our system work as intended, which we completed ahead of schedule in 2025.  
• Validate a full pulser module at the required performance, which is the core driver of our fusion system. Earlier this month, we announced the successful build and validation of a scaled prototype – roughly one-third the size – of a full module. It delivered ~440 GW of peak output power and ~1.1 MV peak voltage in an 80-nanosecond pulse, making it the highest-power single-step pulser module ever demonstrated.
• Once we’ve completed one module, we will manufacture the remaining 155 to form our first fusion system, called the Demonstration System, which we are building in Albuquerque, New Mexico. 
• We will then use our Demonstration System to achieve scientific gain (getting more fusion energy out of the fuel than went into the fuel), followed by net facility gain (more energy output than all energy input) by 2030
• In parallel, we will engineer the systems required for safe and affordable operation, including durable chamber components, tritium handling and fuel-cycle systems, and low-cost targets, among others. 

3. How close are you to demonstrating fusion energy output greater than heating energy input? When will you build a working prototype that can sustain fusion or produce net energy 24/7?

Later this summer we will break ground on our fusion system in Albuquerque, New Mexico, which is designed to achieve net facility gain — more energy output than all energy input — by 2030. We are targeting commercial fusion power (24/7) in the mid-2030s.

4. Are your plans realistic given the first-of-a-kind nature of technology?

Fusion’s promise is enormous — but it is hard. It combines the challenges of first-of-a-kind science and engineering with the complexity of large-scale capital projects.  

We believe Pacific Fusion has the ingredients to meaningfully reduce that risk:

• We are building on established science. Our approach draws directly from the highest-performing fusion experiments ever demonstrated, including ignition at the National Ignition Facility and pulsed-power results at Sandia’s Z Machine. 
• We’ve raised $1 billion in private capital, enabling us to move quickly as we pursue a first-of-a-kind fusion system.
• We are building with exceptional talent. Nearly half of our team comes from the national laboratories, including many people who worked on the highest-performing fusion experiments to date. They are joined by engineers and operators from industry with experience building complex hardware at speed.
• We are establishing a proven track record: Since founding in 2023, we have grown to more than 200 people, expanded operations to New Mexico, and continued to make measurable progress against our technical milestones, including the successful validation of a scaled pulser module prototype earlier this month.

5. Why did Pacific Fusion choose this technology, and what are the technological and economic benefits?

We chose pulser-driven inertial fusion because it combines the strongest scientific foundation with a practical engineering path: 

The scientific basis comes from the highest-performing inertial fusion results at U.S. national laboratories. The engineering basis comes from compact, efficient pulsed-power systems that can be built from replicable modules.

The economic benefits are central to the design: low-cost components, common materials, modular manufacturing, and easier maintenance give us a credible path to power plants that can compete on cost. 

6. Have you confirmed the performance requirements of all components needed for success?

Our most critical hardware milestone is the pulser module, the energy driver of the system.

Each full module is designed to deliver more than a terawatt of peak power in a ~100-nanosecond pulse. The full Demonstration System will use 156 modules firing in tight synchronization to compress a small fuel target and release fusion energy.

We have now built and validated a scaled prototype, roughly one-third of a full module, and shown it delivers the required performance and reliability. Our next milestone is completing and validating a production-scale module, while simultaneously scaling up manufacturing to build the remaining 155 modules on schedule.

7. What economic measures will you evaluate to prove the design can scale commercially?

Pacific Fusion’s system is designed to achieve fusion conditions with a modular architecture that can succeed commercially, because it is:

• Maintainable: Systems are built from low-cost components that can be serviced or swapped without taking an entire plant offline, ensuring reliability and high uptime 
• Manufacturable at scale: Modules are constructed from widely available materials — including oil, plastic, metal and water — and are designed to be efficiently mass-produced on assembly lines.
• Deployable: Our base power plant is designed with a nameplate capacity of 200MW – 300MW, right-sized for cost-effective deployment across a wide swath of the grid without the need for slow and costly transmission upgrades. When needed, multiple fusion power units can be collocated together to supply at gigawatt-scale.

8. Many fusion developers are planning plants below 300 MW. Why does that matter?

A 100-300 MW fusion plant can be easier to finance, easier to site, and more cost-effectively connected to the grid than a very large gigawatt-scale plant. 

9. Can Pacific Fusion produce plants that are competitive with a 300 MW SMR at roughly $1.8 billion? Can utilities make money operating them?

Fusion will only matter if it can compete economically with other firm power sources. Pacific Fusion’s system has inherent strengths – including modular, factory-built pulser modules, made from commonly available materials – will outcompete SMRs on cost and performance. At scale, Pacific Fusion targets firmed solar as the benchmark cost to beat. 

10. What regulatory challenges do you expect in the United States?

Fusion benefits from fewer regulatory challenges due to its relative safety profile: it does not involve a chain reaction, cannot melt down, and does not use fissile material. 

In 2024, the U.S. passed the bipartisan ADVANCE Act, which formally clarified that fusion should not be regulated like conventional nuclear fission reactors. This created a path forward for fusion energy and served as an acknowledgment that fusion’s safety profile is fundamentally different from that of fission’s. Implementing rules anticipated for release by the end of 2027 will provide the regulatory momentum needed for future fusion deployment.

What matters now is implementation, especially at the state and local level, to ensure the timely approval of fusion power plants. By following federal direction, state policymakers can craft a regulatory framework that supports safe deployment with clear but flexible rules, consistent timelines, and efficient processes.

11. What is Pacific Fusion doing to develop a global supply chain? How do you move from custom prototypes to commercial production?

Our system is designed to avoid exotic supply chains. Our pulser modules are built from repeated components using common industrial materials such as metal, plastic, oil, and water. The goal is to move from custom-built prototypes to factory-built modules, then to mass production-scale systems.

12. What is the state of quality and safety standards for fusion? Help or hindrance?

Fusion needs strong standards, but they should be risk-informed. Overly prescriptive rules copied from fission would slow deployment without improving safety, because fusion has a different risk profile. At the same time, serious fusion companies need rigorous quality systems.

A clear, risk-based framework would help the industry by giving stakeholders, including regulators, investors, communities, and customers confidence while allowing companies to build at the speed required.

We’re encouraged by the work the NRC is doing to ensure fusion licensing is risk-informed and based on fusion’s favorable safety profile — regulators have continued to treat fusion as fundamentally safer than fission, with a risk profile much closer to existing medical and research particle accelerators than to conventional nuclear power.

13. What is Pacific Fusion doing to develop the workforce needed to build and operate its plants?

Fusion is moving from research into industrial execution, which means the workforce is much broader than plasma physics PhDs. We need a range of skilled employees, ranging from technicians and manufacturing engineers, to supply chain specialists and operators.

That is one reason New Mexico is important to us. The state has deep national lab talent, a strong applied physics and engineering base, and the opportunity to build education and workforce pathways for technicians and manufacturing engineers to grow the workforce and new fusion industry.

14. Do you have expressions of interest from utilities? What are utilities telling you?

Utilities and large power customers are increasingly focused on the same problem: they need more firm, dispatchable and zero-carbon sources of power. We are having a number of conversations, which we will be happy to share more about in due time. 

15. What is the expected service life of a Pacific Fusion machine?

We are designing our fusion power plants to have a comparable service life as other current conventional thermal generation sources. 

16. How will a Pacific Fusion plant be decommissioned, and how will activated components be handled?

Decommissioning will be regulated by Pacific Fusion’s radioactive materials license with the State in which a plant is located. That license includes a prepayment escrow for funding the decommissioning plan, material handling, waste storage and removal.

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