| 摘要 |
The present invention relates to the detection, in the core of a boiling water reactor, of local power oscillations which oscillate in phase opposition to the power in the rest of the core. A plurality of neutron detectors (K1-Kn) are appointed to be control detectors and at least one neutron detector is appointed to be a reference detector (R1-R4), whereupon for each reference detector, for each one of the control detectors, a phase value is continuously calculated, which phase value corresponds to the difference in phase between the output signal of the reference detector and the output signal of the control detector. In dependence on the calculated phase values, incipient out-of phase ocillations are detected according to a predetermined out-of phase criterion and an alarm signal (OPA) is released if there is a risk for out-of phase oscillations. |
