Reactor Technology: Reactivity Variations

This lecture covers reactivity variations in reactor technology, including short-term variations like Doppler and void coefficients, medium-term variations such as Xe135 poisoning in thermal reactors, and long-term variations related to fuel composition changes with burnup. The means of control to maintain reactor stability and safety are also discussed, emphasizing the importance of compensating for reactivity changes. The lecture delves into the point kinetics equations, Laplace transforms, and the Inhour equation to analyze reactor behavior under different conditions, such as stable periods, delayed and prompt criticality, and the effects of reactivity insertions. Various coefficients like the Doppler effect, fuel temperature, and moderator temperature are explained, along with their impact on reactor performance.