Cardiac measures of nuclear power plant operator stress during simulated incident and accident scenarios

Maintaining optimal performance in demanding situations is challenged by stress‐induced alterations in performance. Here, we quantified the stress of nuclear power plant (NPP) operators (N = 20) during a full‐scale simulator training for incident and accident scenarios. We compared the ambulatory electrocardiography measurements of heart rate (HR) and heart rate variability (HRV), and self‐reported stress during baselines and simulated scenarios. Perceived (scale 0–10) and physiologically measured stress were low during baseline after the scenarios and normal NPP operation (means 1.8–2.2, mean HR 75–80 bpm). During a cognitively challenging scenario simulating a sensor malfunction, the operators' stress was mild to moderate (mean 3.4; HR + 12% from baseline). During simulations of severe accidents of fire and radioactive steam leakage, the experienced stress and cardiac activity were on a moderate to high level (means 4.2 and 4.6; HR + 23% and + 14% from baseline, respectively). Cardiac activity paralleled the self‐reported stress: correlation of self‐reported stress to HR was 0.61 (p