AZ-5 Backfires

Operators press the AZ-5 emergency shutdown believing it will stop the reactor. In the extreme state they have created, the control rods’ graphite tips initially increase reactivity and help trigger the explosion.

A shutdown mechanism that appears safe under normal assumptions can behave dangerously in the off-normal state where it is most needed. “There is an off switch” is not enough unless the switch is robust across the full state space.

This is non-agentic reactor physics and one part of a multicausal disaster, not an AI strategically resisting shutdown.