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:
“You took my heart in your hand
With a friendly smile,
With a critical eye you scanned,
Then set it down,
And said: It is still unripe,
Better wait awhile;”
—Christina Georgina Rossetti (1830–1894)
“It is very considerably smaller than Australia and British Somaliland put together. As things stand at present there is nothing much the Texans can do about this, and ... they are inclined to shy away from the subject in ordinary conversation, muttering defensively about the size of oranges.”
—Alex Atkinson, British humor writer. repr. In Present Laughter, ed. Alan Coren (1982)