Physical Hardening and Siting
Siting and physical hardening determine how well a fixed fusion installation resists attack and environment, and how its shielding and redundancy are laid out.
Siting decisions
Siting sets the foundation for survivability: geology and foundations for a heavy high-field machine, standoff distance from the perimeter, separation between redundant units, and placement of shielding, storage, and fuel handling. A fixed installation can make these choices deliberately — an advantage over any mobile platform.
Hardening measures
- Structural protection sized to the assessed threat.
- Burial or berming where geology and mission allow.
- Shielding that serves double duty against the neutron fraction and against attack.
- Redundant, separated control and cooling paths.
Shielding and hardening together
The 5.44% neutron fraction already requires a shielding boundary. Well-designed shielding contributes to physical hardening, so the two requirements can be met with shared structure. This is a genuine efficiency of a fixed emplacement: the mass that protects people from neutrons also helps protect the machine.
Hardening and siting cannot overcome the availability gate — a hardened machine still trips and needs maintenance. They reduce the probability of damage and support the redundancy that continuity requires. As with everything here, these are design-stage considerations for a machine whose core physics gates remain open.
Shielding that does double duty
Because the machine already needs a shielding boundary for the neutron fraction, that mass can be designed to contribute to physical hardening as well. This shared structure is a genuine efficiency of a fixed emplacement. Siting choices — foundation, standoff, separation — then determine how effectively the hardening protects both people and the machine.