The critical size is the minimum size of a nuclear reactor core or nuclear weapon that can be made for a specific geometrical arrangement and material composition. The critical size must at least include enough fissionable material to reach critical mass. If the size of the fissionable material is less than a certain minimum, fission neutrons escape through its surface and the chain reaction is not sustained.
Famous quotes containing the words critical and/or size:
“Somewhere it is written that parents who are critical of other peoples children and publicly admit they can do better are asking for it.”
—Erma Bombeck (20th century)
“For truly I tell you, if you have faith the size of a mustard seed, you will say to this mountain, Move from here to there, and it will move; and nothing will be impossible for you.”
—Bible: New Testament, Matthew 17:20.