Safety
In most reactor designs, as a safety measure, control rods are attached to the lifting machinery by electromagnets, rather than direct mechanical linkage. This means that automatically in the event of power failure, or if manually invoked due to failure of the lifting machinery, the control rods will fall, under gravity, fully into the pile to stop the reaction. A notable exception to this fail-safe mode of operation is the BWR which requires the hydraulical insertion of control rods in the event of an emergency shut-down, using water from a special tank that is under high nitrogen pressure. Quickly shutting down a reactor in this way is called scramming the reactor.
Read more about this topic: Control Rod
Famous quotes containing the word safety:
“For hours, in fall days, I watched the ducks cunningly tack and veer and hold the middle of the pond, far from the sportsman;... but what beside safety they got by sailing in the middle of Walden I do not know, unless they love its water for the same reason that I do.”
—Henry David Thoreau (1817–1862)
“To emancipate [the slaves] entirely throughout the Union cannot, I conceive, be thought of, consistently with the safety of the country.”
—Frances Trollope (1780–1863)
“I nightly offer up my prayers to the throne of grace for the health and safety of you all, and that we ought all to rely with confidence on the promises of our dear redeemer, and give him our hearts. This is all he requires and all that we can do, and if we sincerely do this, we are sure of salvation through his atonement.”
—Andrew Jackson (1767–1845)