Effective use of local and global component of neutron noise signals

Thermal hydraulics of two-phase natural circulation reactors pose stiff challenges while establishing stable operation at all power level, establishing thermal margin, thermal hydraulics related to refueling, channel burn out caused by small break LOCA, flow instability etc. In core detectors such as SPNDs are very sensitive to perturbation to neutron flux. By the definition of 1970s, neutron flux is made of the global component generated by the reactivity noise that fluctuates in phase with the whole reactor, and the local component that originates from the axially propagating perturbations. Perturbation changes the neutron field in its neighborhood, called the local component. The paper deals about effective use of SPND signal for detecting in core thermal hydraulics during steady state operation and during reactor shut down.