Po 2t /DT
Po et /
Po 10SUR (t)
Reactor Theory (Reactor Operations)
Reactor Kinetics Summary (Cont.)
Equations (4-9) and (4-11) can be used to calculate the stable reactor period and
The concept of doubling time can be used in a similar manner to reactor period to
calculate changes in reactor power using Equation (4-12).
The reactor period or the startup rate can be used to determine the reactor power
using Equations (4-6) and (4-10).
Prompt jump is the small, immediate power increase that follows a positive
reactivity insertion related to an increase in the prompt neutron population.
Prompt drop is the small, immediate power decrease that follows a negative
reactivity insertion related to a decrease in the prompt neutron population.
Prompt critical is the condition when the reactor is critical on prompt neutrons
When a reactor is prompt critical, the neutron population, and hence power, can
increase as quickly as the prompt neutron generation time allows.
Measuring reactivity in units of dollars is useful when determining if a reactor is
prompt critical. A reactor that contains one dollar of positive reactivity is prompt
critical since one dollar of reactivity is equivalent to