Presently, most of the international waste management programs include metallic canisters as part of the engineered barriers.
Prototypes developed in different countries show a similar design.
As representative of the thick-walled cast iron- steel canisters the German POLLUX is shown on the left, a very heavy construction with a wall of about 20 cm thickness.
Maybe Sweden and Finland have the most advanced disposal projects for commercial nuclear waste.
Foreseen are copper canisters with medium wall thickness of 50 to 60 mm, known as KBS-3 type. A heavy cast iron insert holds the fuel elements in proper position and thus contributes to the overall stability.
On the right, the INL STANDARD is shown as representative of the thin-walled steel canisters. The German BSK 3 canister has a very similar design. Its wall thickness is about 40 mm.
To understand the challenges for ceramic components as part of disposal systems, some safety requirements and some conditions in the repository must be mentioned.