China syndrome


noun

a hypothetical nuclear-reactor accident in which the fuel would melt through the floor of the containment structure and burrow into the earth.

Origin of China syndrome

First recorded in 1970–75; from the jocular notion that the hot reactor core would pass through to the other side of the earth
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019