In a nutshell:
Since joining Kyoto Fusioneering (KF) in April 2024, Koichiro has been drawing on his extensive experience in the nuclear energy field. He is now working on the development of power generation technologies at UNITY-1, KF’s integrated testing facility that demonstrates the fusion blanket and thermal cycle system by simulating the environment of a fusion power plant.
You’ve built your career in the field of nuclear energy. What first sparked your interest in this area?
It all started back in my senior year of high school, when we learned about nuclear fission and radioactive decay. I was fascinated by the idea that one element could transform into another—it felt like I was witnessing a hidden alchemy of nature! That curiosity led me to study nuclear engineering at university and to then gain my master’s degree at graduate school.
By the time I had finished studying, Japan was in the midst of a boom in nuclear power plant construction. I wanted to apply what I had learned and work as an engineer, so I joined a manufacturer involved in designing and building nuclear power plants.
After joining the company, I was quickly assigned to the turbine plant design division, where I worked on detailed plant design and commissioning, including the procurement of major equipment such as turbines & pumps. There was quite a gap between what I had studied in school and what was required in practice—I encountered many unfamiliar technical terms and regularly felt overwhelmed. But by asking senior colleagues questions and studying past design documents, I gradually built up my knowledge piece by piece.
Over time, I expanded the scope of my work to include different types of plant design, project management, and even business development for new clients.
Around the 2000s, as the company started to focus more on overseas markets, I also began taking part in international nuclear projects.
What kind of experience did you gain through these overseas projects?
I was mainly involved in projects in China and the US, and I was struck by how different their ways of working were compared to what I’d experienced in Japan.
In China, I worked with local manufacturers to negotiate contracts for supplying equipment such as turbine generators to new power plants. I recall many of the contract negotiations being extremely intense and remain some of my most memorable experiences.
We held the discussions using what was called a “subcommittee system,” where meetings were divided by technical area. In the mechanical subcommittee that I led, it was just me representing our side—facing about ten engineers from the client’s team. Since I was responsible for every aspect of the negotiation, I had to proceed with both confidence and a strong sense of responsibility—while getting used to being outnumbered!
On one particular deal, after more than a month of negotiations, we successfully concluded a large contract that secured revenue for the company for the next decade. When it was finally signed, I felt a deep sense of relief—and an even deeper sense of accomplishment.
How about your experience in the US?
My experience in the US was very educational – but for different reasons. While there, I collaborated with a local engineering company on the basic design required for licensing and approval of a new power plant. The project management system in the US was highly developed and gave me a lot to learn from.
At my company in Japan, teams were typically organized by function with project managers—usually experienced engineers—relying mainly on their personal experience and intuition to guide their teams. In contrast, US projects were managed on a project-based structure, where the project manager had full authority and responsibility over the entire project and made decisions accordingly. Experiencing this more systematic approach to project management firsthand was incredibly valuable.
After returning to Japan, I had more opportunities to lead projects myself, combing the hands-on negotiation skills I’d learned in China with the management, resource allocation, and communication skills I learned in the US—all of which have proved immensely useful.
With such a rich career in both domestic and international projects, what led you to join Kyoto Fusioneering?
As I was approaching retirement from my previous company, I started looking for new opportunities in the energy sector where I could continue to use my experience. I was particularly interested in hydrogen-related projects, another promising future energy source.
Then, by chance, I came across a newspaper article about fusion energy—that was my first encounter with KF. Although I had studied a bit about fusion back in university, I thought I had forgotten most of it—but reading that article rekindled my early fascination with nuclear science and reminded me of my keen interest for learning more about the field of fusion power. I was also deeply drawn to the fact that, unlike many other startups & research institutions, KF was focusing deeply on the engineering of fusion plants which was an area I knew I could make full use of my background.
Moreover, KF’s CREDO particularly resonated with me—especially the phrase “Enjoy the Challenge.” It perfectly captured what I was looking for: an environment focused on embracing new challenges and actively encouraging growth. Connecting with that message gave me the push I needed to take the leap.
What kind of work are you currently involved in at KF?
I’m part of the Plant Technology Division, working on UNITY-1, our integrated test facility. We’ve intentionally designed the facility to simulate the real-world environment of a fusion power plant, allowing us to showcase our range of power generation technologies to our clients and partners in the sector.
Specifically, I’m leveraging my experience in nuclear turbine plant engineering to design, install, and test the power generation system. In this system, the heat energy carried by a liquid metal (lithium-lead) that simulates the reactor is transferred to compressed air through a heat exchanger, which then drives a turbine generator. It’s essentially the heart of the thermal cycle system.
Right now, I’m hardly working for installation and inspections of the turbine generator. We plan to conduct the first power generation demonstration very soon, showcasing how fusion energy can be converted to electricity.
What makes UNITY-1 unique from your perspective as an engineer?
I think the most distinctive feature of UNITY-1 is its ability to circulate high-temperature liquid metal stably and continuously.
Because the liquid metal is heated and maintained at temperatures between 400-500°C, we need to carefully select materials for components and piping to ensure they can withstand such extreme conditions. We also utilize techniques like wrapping heaters around pipes and valves to maintain temperature stability.
Its method of operation is also unique. During startup, for instance, the high-density liquid metal stored in the tank cannot be lifted by an ordinary pump. Instead, we use argon gas pressure to gradually fill the system. During shutdown, careful operation is required to prevent the liquid metal from solidifying inside the pipes as the temperature drops, which could cause blockages. We have to pay close attention to the sequence of valve operations & temperature control of the system.
Thanks to these accumulated technologies and operational know-how, UNITY-1 has become the world’s only facility capable of circulating high-temperature liquid metal stably. This capability enables a wide range of demonstration tests—including those for the power generation systems that will drive fusion energy sector forward.
What do you find most fulfilling and exciting about working on UNITY-1?
UNITY-1 development involves a wide variety of technical challenges that are completely unique to fusion energy. Every day brings new trials and errors, but that’s exactly what makes the work so exciting for me.
I also love how KF moves at a remarkable speed—with everyone working together towards a shared goal. Because of this high level of organizational focus, new ideas or the equipment can be adopted almost immediately. Seeing those ideas take shape so quickly gives me a strong sense of fulfillment and excitement to come into work every day.
At the same time, fusion energy, much like nuclear fission, demands the very highest levels of quality and safety. This is why KF places such a strong emphasis on reviewing design drawings thoroughly, maintaining accurate testing and inspection records—to ensure a safe and productive working environment for everyone involved. Looking ahead, we’re planning demonstration tests that simulate temperatures as high as 1,000°C—the same temperature levels expected from actual fusion reactions.
Reaching this next level will require tackling even tougher challenges, including developing new materials and insulation technologies.
As someone who has spent decades as an engineer, what guiding principles do you value most?
In plant development, many specialized engineers work together, so it’s crucial to pay close attention to the interfaces between disciplines. It’s not enough to just cover your own area of expertise—you also need to understand the perspectives of others. That’s why, during design reviews or technical meetings, I make it a point—perhaps a bit insistently—to comment on areas beyond my own specialty.
I have always thought of this as being like the “norishiro”—a Japanese term meaning the overlap that holds two pieces of paper together. I have carried that mindset all the way into my current work at KF.
Finally, what do you hope to achieve at KF?
My immediate goal is to successfully demonstrate power generation through the ongoing development and testing of UNITY-1. Beyond that, I’m also involved in several other projects, and hope to continue working across teams and divisions while consistently taking on new challenges.
Overall, I want to make full use of the knowledge & experience I have learned from my years in the nuclear industry and contribute as much as I can to help KF realize fusion energy!
