reactor – n. a large device that produces nuclear energy

propeller – n. a device with two or more blades that turn quickly and cause a ship or aircraft to move

decommission – v. to officially stop using (a ship, weapon, dam, etc.) : to remove (something) from service

sievert – n. physics the standard unit in the International System of Units (SI) of dose equivalent having the same biological effect as one joule of x-rays per kilogram of recipient mass (or one gray)

efficient – adj. capable of producing desired results without wasting materials, time, or energy