arXiv:2610.41007v1 Announce Type: cross Abstract: Operational technology now faces attackers whose tempo is set by AI. We present ADS-OT, an adaptive dynamic security framework modelling defensive posture as a partially observable decision problem. A reinforcement-learning policy adapts monitoring, access, deception, and segmentation under a safety-governance layer, reducing attack-path completion, detection, and containment versus static baselines.