In a nutshell:
Tomoyo joined Kyoto Fusioneering (KF) as a fuel cycle engineer in October 2023, bringing expertise in both chemical engineering and construction management. After studying chemical engineering at university, he spent several years overseeing the design and construction management of high‑rise buildings and semiconductor fabrication plants at a contracting firm. At KF, Tomoya leverages his experience to develop measurement instruments used in fusion fuel cycle systems and to design layout and equipment specifications for fusion facilities such as UNITY‑2.
Could you tell us about your role at Kyoto Fusioneering (KF)?
I work on a team developing fusion fuel cycle systems in the Plant Technology Division. My responsibilities include the construction of measurement instruments as well as the design of equipment and facilities.
Specifically, I develop instruments used to measure the concentration of hydrogen isotopes — the fuel for fusion energy — as well as radioactive levels and impurities contained within the system. These include tools such as Raman spectrometers, gas chromatographs, and ionization chambers. I’m also involved in the equipment and building layout design for UNITY‑2, an integrated fusion fuel cycle testing facility currently being built by Fusion Fuel Cycles, a joint venture between KF and Canadian Nuclear Laboratories (CNL).
How is the development of UNITY‑2 progressing on the ground?
Given the entire UNITY‑2 system must fit inside an existing building owned by CNL, construction has been quite complicated. While designing the plant, we rigorously verify equipment size, installation methods, and performance requirements to ensure it aligns with the facility’s original dimensions. We also carefully consider the space needed for transportation, installation, experiments, and maintenance. It all requires precise calculation and creative problem-solving.
Another challenging area is the design of glove boxes, sealed enclosures equipped with rubber or resin gloves that allow operators to safely handle radioactive materials. Designing the interior so that all necessary components are within arm’s reach is particularly complex, often requiring repeated fine adjustments—sometimes down to the millimeter—to finalize the design.
While the work can be demanding, it is incredibly rewarding to build systems that have never existed before with your own hands. This is what makes engineering truly exciting and satisfying.
Have you always been interested in engineering?
My parents worked in the architectural field, so I was interested in building things from a young age. I initially considered majoring in architecture at university, but a structural falsification scandal at the time had a major impact on the construction industry. That prompted me to reconsider my path and ultimately choose to study chemical engineering instead.
I felt that chemical engineering would allow me to realize my childhood desire to build something — just through a different approach: scaling chemical reactions from the lab to a full‑fledged chemical plant.
Through my coursework at university, I gained a wide range of knowledge in areas such as reaction and process engineering. However, my mindset began to shift once I entered graduate school, and my days became consumed by research.
In my graduate lab, we operated under the hypothesis that the human body is the most efficient chemical plant in existence, conducting basic research to uncover the reactions taking place within it. While the work was intellectually stimulating, it often took years to obtain tangible results, and it made it difficult to feel like I was moving forward. That’s when I realized that I was better suited to being an engineer rather than a researcher.
When job hunting, I intentionally focused on companies where I could be directly involved in engineering activities such as design and construction, rather than research alone. In the end, I joined an HVAC‑focused construction company whose culture felt like a good fit.
What kind of experience did you gain at the HVAC company?
At the company, I worked on the design and construction management of high‑rise buildings and semiconductor fabrication plants in Tokyo. In the construction industry, you learn a lot by working onsite and seeing things for yourself. So, I actively took on a wide range of tasks early on to build this on-the-ground experience.
I also volunteered for difficult construction challenges that others tended to avoid or deprioritize due to the workload. At first, I often hit roadblocks since there were many things I didn’t understand. However, with guidance from senior colleagues and partner companies, I gradually worked through these challenges, gaining invaluable experience along the way.
Over time, I found there were more things I could handle on my own, and I truly felt myself growing as an engineer. I also worked harder than most of my peers, building my knowledge and skills one step at a time. This gave me broader exposure to the industry and built my confidence as an engineer. During this time, I was driven by the sheer satisfaction of creating something, and I often found myself completely absorbed in my work.
At the same time, there were moments when my eagerness to take on as many tasks as possible pushed me to my physical limits, and I nearly burned out. Even so, I was able to ask my teammates for help instead of carrying everything on my own.
In particular, the experience of advancing projects with the support of senior colleagues in my first year of university became the foundation for later leading multi-billion-yen projects as a site manager. It also taught me firsthand the true value of teamwork.
What prompted you to consider moving to Kyoto Fusioneering?
The trigger was a message from Yoshinao, the Head of the Fuel Cycle Department at KF, who I have known since my university days. Out of the blue, he reached out to me saying, “I moved to this new company—would you like to hear a bit about it?”
At first, the message caught me off guard. But I was about a year away from completing a semiconductor plant project at the time, so I was reflecting on my career anyway. Having already worked on several large‑scale construction projects, I started to feel that challenging myself in a different industry could be a good next step to broaden my experience as an engineer.
When I spoke with Yoshinao, I learned that KF was actively developing essential technologies to realize fusion energy — a next‑generation power source. The idea of building fusion energy plants resonated strongly with me, as it would allow me to apply both my construction experience and my background in chemical engineering. This ability to combine my skillsets ultimately led me to join KF.
To be honest, I did feel a little anxious about moving to a startup given the change in working environment. However, that concern was outweighed by the fact that private companies were taking the lead in advancing fusion energy and investing significant resources in its development.
In the end, hearing KF’s mid‑to-long‑term strategy directly from the executive team during my interviews made me feel confident that KF was a place where I could continue taking on long‑term challenges in my career. This was truly the decisive factor.
Have there been any discoveries since joining KF?
What has stood out to me the most is that even though fusion energy is a completely new field for me, I’ve been able to fully leverage the experience I’ve built so far.
At my previous job, I worked on overall design and construction management for buildings and plants, developing the ability to think holistically about how to arrange equipment and workflows within a limited space. That perspective has proven invaluable when designing fusion plants such as UNITY‑2, as well as when planning R&D areas at KF headquarters.
I was also struck by how many talented people work here. While there are still many technical challenges to overcome before achieving fusion energy, KF unites and galvanizes experts across disciplines — from mechanical design to thermal‑fluid analysis. By leveraging each other’s strengths, we’re steadily making progress towards our shared goal of commercial fusion energy.
Is there anything you consciously keep in mind in your daily work at KF?
I am always mindful of maintaining close communication with research institutes and partner companies since I believe fusion energy can’t be realized through a single technology or the efforts of a single company alone. Progress comes from bringing together expertise from many different fields.
That’s why I actively attend domestic trade shows to research potential partners. Fusion energy has strong connections to a wide range of industries including semiconductors and hydrogen production, but products optimized for fusion applications remain scarce. So, I make it a point to speak directly with manufacturers at exhibitions, explaining our requirements and asking things like, “Would it be possible to create something like this?”. Through these open discussions, we exchange ideas and build new partnerships. In fact, we’re currently exploring the joint development of fuel gas measurement instruments and control systems with a manufacturer we met at a recent semiconductor exhibition.
Also, every time I speak with domestic manufacturers, I am reminded of Japanese craftmanship. Just imagining how this technical excellence could be applied to fusion energy‑related equipment fills me with excitement.
Finally, what would you like to achieve at KF?
I would like to develop standardized fusion fuel cycle equipment that can be applied to any type of fusion device. To accomplish that, we would need to conduct experiments with UNITY‑2 to develop measurement instruments, valves, and materials that can operate under extreme conditions like high temperatures, cryogenic environments, and tritium exposure.
As of now, KF is the only company working on integrated fusion plant engineering — I believe it is KF’s mission to be the first to complete a fusion plant.
With that sense of responsibility, I hope to keep challenging myself, building on new experiences, and ultimately contributing to making fusion energy a reality.
