Stochastic non-linear reactor model near the Hopf bifurcation

Stochastic nonlinear reactor model near the Hopf bifurcation point is verified experimentally and theoretically based on the probability distributions of time-series data of power oscillations measured in the nuclear safety research reactor at JAERI. We have found that the contribution of parametric noise becomes anomalously large near the onset of power oscillation. The physical origin of anomaly is discussed from the viewpoint of stochastic nonlinear reactor dynamics.