The fuel of the future is already here: why TRISO matters

To address the surging energy demands of AI infrastructure and cloud computing, Amazon is investing in next-generation nuclear technology, and at its core is the TRISO (tristructural isotropic) fuel particle.

TRISO is a tiny particle the size of a poppy seed (under 1mm), a 'micro-containment system' that places enriched uranium at its core and wraps it in three layers of ceramic shell (pyrolytic carbon, SiC, pyrolytic carbon). In particular, the SiC (silicon carbide) layer acts as a pressure vessel with a high melting point above 2700°C, maintaining structural integrity even under extreme accident conditions.

Key characteristics include:

• Outstanding safety: It has demonstrated high thermal durability, showing almost no defects even after being heated at 1600°C for 300 hours.
• Operational efficiency: Through pebble-bed configurations (e.g., X-energy's Xe-100), fuel can be replaced while the reactor is running, enabling real-time monitoring of fuel consumption.
• Long-term stability: Spent fuel rods are more stable than conventional fuel, maintaining stability for up to 100,000 years.

Currently, TRISO fuel production is actively underway at the kilogram scale, and deployment of the Xe-100 reactor is being pursued at the Cascade Energy Center, in which Amazon has invested.