Inside the XE-100

The XE-100 converts nuclear energy into electricity or industrial steam through a defined sequence governed by material behavior and core physics. TRISO-X fuel, a high-temperature graphite core, and inert helium coolant are designed to operate together through predictable physical principles to produce cleaner, safer, and more reliable energy.

Each element of the system is engineered around inherent safety characteristics and high-temperature performance. Rather than relying on layers of complex mechanical systems, the XE-100 is designed to use durable, proven materials, passive safety features, and innovative design principles to deliver both electricity and industrial-grade steam from a single standardized reactor design.

Nuclear Fission

Nuclear fission begins inside poppy-seed-sized uranium kernels encapsulated within multiple ceramic layers, forming TRISO fuel particles. These particles are embedded within a graphite matrix inside spherical fuel pebbles that circulate through the reactor core. As uranium atoms split, heat is released into the surrounding graphite structure.

Graphite Moderation

The graphite core performs two essential functions. It moderates neutrons to sustain a controlled chain reaction and conducts heat away from the fuel particles, distributing thermal energy evenly across the core. This high-temperature graphite maintains structural integrity under operating conditions, providing thermal stability and consistent reactor performance.

Helium Coolant

Pressurized helium circulates continuously through channels in the graphite core, absorbing thermal energy from the heated fuel and core structure. Helium remains chemically inert and single-phase at operating temperatures, enabling efficient heat transfer without phase change or material degradation. The heated gas exits the reactor pressure vessel carrying thermal energy toward the steam generator through a cross-duct.

Heat Exchange

Hot helium enters the steam generator where thermal energy transfers across sealed metal tubing into a separate water loop. The two systems remain physically isolated, ensuring that only heat—not radioactivity—moves into the secondary circuit. As water absorbs energy, it converts into high-temperature steam while cooling the helium which returns to the reactor to repeat the cycle.

Steam Generation

The steam generator produces steam at temperatures up to approximately 565°C. This steam can drive a turbine to generate electricity or be delivered directly to industrial facilities that require high-temperature process heat. A single XE-100 module can provide both grid-scale power and industrial thermal energy from the same standardized reactor design.

Passive Safety

If core temperatures rise, inherent physical feedback reduces the rate of fission without external intervention. As materials expand, neutron interactions decrease, slowing the reaction naturally. This negative temperature response allows the reactor to stabilize on its own, maintaining safe conditions through fundamental passive safety properties rather than active mechanical systems.