Power history

Power History refers to the power of a nuclear reactor over an extended period of time. Power history is important for calculations and operations that involve decay heat and fission product poisons.

For example, a nuclear reactor that has operated at 100% power for 100 hours and then has dropped down to 20% power for 5 hours will have a different amount of decay heat and fission product poisons than the same nuclear reactor operating at 20% power for 105 hours. This is because the second reactor has a different power history.