TRISO Nuclear Fuel

  • 11 Aug 2025

In News:

The United States Department of Energy (DOE) has selected Standard Nuclear as the first company to establish a domestic supply chain for TRi-structural ISOtropic (TRISO) nuclear fuel, marking a major step toward reducing dependence on Russian uranium and advancing nuclear innovation. The initiative, part of DOE’s Fuel Line Pilot Program (2025), is designed to strengthen US energy security, promote private sector participation, and accelerate the deployment of advanced nuclear reactors.

Why TRISO Matters

TRISO is a next-generation nuclear fuel specifically engineered for high-temperature gas-cooled reactors (HTGRs) and molten salt-cooled reactors, both of which fall under Generation IV (Gen-IV) advanced reactor designs.

  • Composition: TRISO fuel consists of a uranium–carbon–oxygen fuel kernel encapsulated by three protective layers of carbon and ceramic materials.
  • Form: The particles are extremely small—seed-sized—and can be fabricated into cylindrical pellets or “pebbles.”
  • Key Features:
    • Extreme durability: Resistant to neutron irradiation, corrosion, oxidation, and very high temperatures.
    • Self-containment: Each particle acts as its own containment system, preventing radiation leakage even under extreme reactor conditions.
    • Versatility: Compatible with multiple advanced reactor designs, including small modular reactors (SMRs).

This makes TRISO structurally and functionally superior to conventional nuclear fuels, ensuring safer, more reliable, and more efficient reactor performance.

Strategic Implications

  • Energy Security & Supply Chains
    • The US has historically relied on imports of enriched uranium, particularly from Russia.
    • By developing domestic TRISO production in Tennessee and Idaho, the DOE seeks to build a resilient nuclear fuel ecosystem independent of geopolitical disruptions.
  • Advanced Reactor Deployment
    • DOE’s Advanced Reactor Demonstration Program targets at least three new advanced reactor designs to achieve criticality by July 4, 2026.
    • TRISO fuel is central to this push, enabling safer operation of SMRs and Gen-IV reactors, both of which are crucial to America’s clean energy transition.
  • Private–Public Partnership
    • Standard Nuclear will finance construction, operation, and decommissioning of TRISO fabrication facilities.
    • Reactor developers will source nuclear material feedstock, partly through DOE’s high-assay low-enriched uranium (HALEU) allocation program.
  • Technological Momentum
    • Other firms, such as BWX Technologies (BWXT), have also developed TRISO production lines, including uranium nitride TRISO, in collaboration with Idaho and Oak Ridge National Laboratories.
    • These advancements reinforce US leadership in nuclear innovation while supporting its broader climate and national security goals.