Epri - Reactor Theory Exam Questions & Answers 2023/2024

Active and passive safety systems- {Ans: An example of an active system is Emergency Core Cooling Systems that supply water for cooling the reactor and removing decay heat. An example of a passive system is the gravity-driven fall of a control rod in a PWR.}Pressurized Water Reactor {Ans: A nuclear reactor system that pressurizes the coolant water to a high enough pressure to prevent boiling in the core; the heated water leaves the core and flows through a steam generator where steam is produced and used to drive turbines}Cold Water injection Accident {Ans: Negative moderator temperature feedback assures a lowering of reactivity as the moderator heats up. However, injection of a slug of cold water into the core will increase the reactivity, as in the inadvertent startup of one of the loops in a PWR that was idle for an extended period.}Heat Exchanger {Ans: A device used to transfer heat from one medium to another; in nuclear plants, steam generators and condensers are examples of heat exchangers, the former transferring heat from the primary coolant to the secondary coolant of a PWR and the latter transferring the heat from steam to water from a cooling tower