Waste Class by Material

Each candidate structural material maps to a characteristic waste outcome; the mapping is how design choices become disposal outcomes.

The waste class a component ends up in is largely decided when its material is chosen. Different structural materials, exposed to the same neutron flux, produce different activation and therefore different waste outcomes. Making that mapping explicit connects the materials program directly to the disposal account.

Material-to-class mapping (schematic)

• SiC/SiC composite: lowest activation; large clearable fraction after modest decay.
• Vanadium alloy (pure): low activation; mostly LLW, recyclable after decay.
• Reduced-activation steel: low-to-moderate; ILW when fresh, decaying toward LLW.
• Tungsten armor: short/medium-lived; LLW after decay, some in-sector reuse.
• Conventional steel (for contrast): long-lived tail from Nb/Mo/Ni — avoided for this reason.

This mapping is why material selection is treated as a waste decision, not just a mechanical one. Choosing SiC or vanadium for a high-flux region can move that component from ILW toward clearable, and rejecting conventional steel avoids a long-lived tail that no amount of decay storage would remove.

Because the mapping is computed in advance, every structural decision can be scored on two axes at once — mechanical fitness and waste outcome — before it is committed. That dual accounting is how the low-activation strategy is enforced in practice rather than hoped for after the fact, and it means the disposal category of a finished machine is largely known while it is still a drawing.

The mapping is schematic and depends on impurity control and neutron spectrum. It is a design-and-simulation framework for machines not yet built, used to make sure every structural choice is checked against its waste consequence, not only its strength.