Enhanced Safety Characteristics

Safety Benefits of Lightbridge’s Metal Fuel Technology

The following inherent design features of the Lightbridge metal fuel technology are expected to enhance safety characteristics under normal operation and certain off-normal events. A key part of the in-reactor and out-of-reactor testing planned by Lightbridge includes experiments to confirm and demonstrate these safety benefits.

Lower fuel operating temperature (380°C for the metallic fuel v. 1500°C for oxide fuel):

• Reduces the amount of heat that must be dissipated into the coolant at reactor shutdown and shortens the time required to do so.

Increased heat transfer between fuel and coolant that improves fuel coolability:

• Higher thermal conductivity of metal vs. oxide – Improves the speed at which heat from the fuel can be dissipated into the coolant;
• Increased fuel rod surface area (~35-40% greater); and
• Improved coolant mixing due to helical twist – Facilitates heat dissipation into the coolant and reduces local hot spots in fuel rods.

Improved cladding integrity due to metallurgical bonding of fuel to the cladding:

• Helps retain radioactive material inside the fuel rod in case of cladding breach.