Lesson 5 5.6 Vitrification of High Level Waste

The vitrified product has several desirable properties:

  • Highly leach-resistant: The rate at which radionuclides can be dissolved from the glass matrix by water is extremely low.
  • Good thermal conductivity: Allows the heat generated by radioactive decay to be dissipated.
  • Reasonable structural integrity: The glass is mechanically robust.
  • Resistant to radiation damage: The glass structure is not significantly degraded by the intense radiation field from the contained waste.
  • Accommodates all waste species: A single matrix can hold all the fission products and minor actinides present in HLW.
  • Volume reduction: The process reduces the overall waste volume by a factor of approximately three compared to the liquid form.

Key Point: The leach-resistant vitrified glass combined with the corrosion resistance of the stainless steel canister material constitutes the primary safety barrier for the high-level waste.