On Tuesday morning, Commonwealth Fusion Systems (CFS) reached a major milestone in the development of its SPARC demonstration reactor by installing a key component: the cryostat base. This installation marks a significant step forward in CFS’s pursuit of commercial fusion energy, moving the project from infrastructure construction to the assembly of the reactor’s core components.
The Cryostat Base: A Key Element
The cryostat base, a 24-foot wide, 75-ton stainless steel circle, serves as the foundation for the tokamak—the central component of the fusion reactor. Manufactured in Italy, the base was transported to CFS’s facility in Devens, Massachusetts, where it will play a critical role in facilitating fusion reactions. The installation of the cryostat base is vital for maintaining the extremely low temperatures necessary for the operation of the tokamak, which is designed to house and sustain the plasma for fusion.
Alex Creely, director of tokamak operations at CFS, highlighted the significance of the installation, stating, “It is the first piece of the actual fusion machine.” After more than three years of intensive construction efforts, the installation signifies a shift in focus from building infrastructure to working on the core components that will bring the reactor to life.
The Promise of Fusion Power
CFS is part of the growing number of emerging startups aiming to harness the power of nuclear fusion—a clean, virtually limitless energy source capable of producing electricity from hydrogen derived from seawater. As the demand for energy continues to rise, driven by sectors like electric vehicles and data centers, fusion energy is seen as a potential solution to meet future power needs while significantly reducing carbon emissions.
With support from notable entities such as Bill Gates’s Breakthrough Energy Ventures, CFS is positioned as a leading contender in proving the commercial viability of fusion energy. In December, the company announced plans to construct its first full-scale commercial reactor near Richmond, Virginia. The SPARC reactor, expected to be operational by 2027, could become the first tokamak to generate more power than it consumes.
Critical Cooling Mechanisms
One of the biggest challenges in fusion energy is maintaining the extreme conditions needed for fusion reactions. Tokamaks, like SPARC, use superconducting magnets that must be cooled to –253 degrees Celsius using liquid helium. The cryostat base acts as an insulating layer, helping to preserve these low temperatures. Creely explained the importance of this component, saying, “The cryostat base is basically like the bottom of a thermos,” ensuring that the necessary cooling is maintained for the superconducting magnets to operate effectively.
Installation Process
Once the cryostat base arrived at the facility, CFS’s team conducted thorough inspections to ensure there was no damage during shipping. After confirming its condition, the installation began by positioning the base onto bolts placed on the concrete foundation, followed by grouting it into place. This meticulous process took several days to complete, ensuring the foundation was stable and secure.
Looking Ahead
Work on completing three additional components of the tokamak is progressing simultaneously, with assembly expected to begin in late 2023 or early 2024. Once the components are assembled, CFS will move into the commissioning phase, a crucial step that will test the functionality and integration of all parts of the system. The commissioning process will take several months, after which the reactor will be one step closer to demonstrating the potential of fusion power.
As Creely emphasized, “This is the first of a kind. There’s not just like an on button and it turns on.” The journey to achieving operational fusion power remains a complex and groundbreaking endeavor, but with each milestone, CFS is getting closer to unlocking a clean and sustainable energy future.
