Robust and efficient power regulation is essential for the safe operation of molten salt breeder reactors (MSBRs), which exhibit strong nonlinearities, time-varying dynamics, and significant modeling uncertainties. This paper develops an event-triggered \(H_\infty \) -based fractional-order proportional–integral–derivative (FOPID) control framework for MSBR power regulation under mixed additive and multiplicative output uncertainty. The uncertainty structure explicitly captures sensor imperfections, unmodeled output dynamics, and process drift. A graphical \(H_\infty \) tuning methodology is employed to determine stabilizing controller parameters with explicit robustness margins. An event-triggered execution mechanism is incorporated to generate aperiodic control updates, thereby reducing computational and communication burden while ensuring the existence of a strictly positive minimum inter-event time. A Lyapunov-based analysis establishes input-to-state stability of the closed-loop system under non-periodic updates. To improve adaptability under time-varying operating conditions, a long short-term memory (LSTM) network is integrated to predict fractional orders and update weights online within stability-admissible bounds. Simulation studies demonstrate accurate power tracking, effective disturbance rejection, reduced settling time compared with benchmark methods, and robust performance under actuator faults and large parametric uncertainties. Monte Carlo analysis further confirms stable operation and consistent robustness across the considered uncertainty range.
