Criticality
State where neutron production equals losses, sustaining steady chain reaction in fissile material.
Achieved when k-effective = 1; subcritical (k<1) for safety in storage, supercritical (k>1) for transients. Monitored via neutron detectors in reactors. Criticality accidents rare but highlight handling risks.
Why it matters now
Criticality safety critical for 2025-2026 HALEU handling and SMR fueling amid supply chain ramps for data center projects.