¯effeffSUR26.06PP_{o} 2^{t /DT}PP_{o}e^{t /}PP_{o}10^{SUR (t)}REACTOR KINETICSDOE-HDBK-1019/2-93Reactor Theory (Reactor Operations)NP-04Rev. 0Page 22Reactor Kinetics Summary (Cont.)Equations (4-9) and (4-11) can be used to calculate the stable reactor period andstartup rate.The concept of doubling time can be used in a similar manner to reactor period tocalculate changes in reactor power using Equation (4-12).The reactor period or the startup rate can be used to determine the reactor powerusing Equations (4-6) and (4-10).Prompt jump is the small, immediate power increase that follows a positivereactivity insertion related to an increase in the prompt neutron population.Prompt drop is the small, immediate power decrease that follows a negativereactivity insertion related to a decrease in the prompt neutron population.Prompt critical is the condition when the reactor is critical on prompt neutronsalone.When a reactor is prompt critical, the neutron population, and hence power, canincrease as quickly as the prompt neutron generation time allows.Measuring reactivity in units of dollars is useful when determining if a reactor isprompt critical. A reactor that contains one dollar of positive reactivity is promptcritical since one dollar of reactivity is equivalent to .eff