Neutron Damage and Activation
How fusion neutrons degrade materials over time, and how Kronos accounts for it.
- Breeder neutron fraction
- 79.7%
- Burner neutron fraction
- 5.44%
Fusion neutrons displace atoms in structural materials (measured in displacements-per-atom) and can transmute them into radioactive isotopes. This sets component lifetimes and the plant's waste profile. The breeder, being neutron-rich (79.7%), carries most of this load; the burner far less (5.44%).
Kronos screens activation and waste class per component rather than assuming low-activation materials solve the problem for free.
Fusion neutrons both displace atoms (measured in dpa) and transmute them into gas and radioactive isotopes, degrading materials and setting their lifetime. The neutron-rich breeder (79.7% neutrons) carries almost all of this load; the burner (5.44%) far less. Low-activation steels are chosen so the damage is bounded and the resulting waste is short-lived.
Common questions
They displace atoms from the lattice (measured in dpa) and transmute them into gas and radioactive isotopes, degrading materials and setting component lifetimes. The neutron-rich breeder (79.7%) carries almost all of this load.
By low-activation steels chosen so their decay products are short-lived, and by designing damaged components — first wall, blanket — to be replaceable rather than permanent.