The stability of boiling water reactors as a catastrophe phenomenon

Paper i proceeding, 2015

The stability of boiling water reactors (BWRs) is revisited in terms of catastrophe theory. The hypothesis is proposed that the stability parameter (decay ratio) of a complex, many-variable non-linear system might obey a cusp catastrophe. The incentive for this surmise comes from indications in real measurements that in certain cases the decay ratio appears to behave discontinuously and might show a hysteresis as a function of the control parameters reactor power and coolant flow. Such observations can be explained by a phenomenological catastrophe model suggested in this article. Since a cusp-type behaviour implies that the decay ratio is many-valued in a certain region of the power-flow map, a mechanism is suggested how a Hopf bifurcation with multiplicative noise can lead to such a behaviour.