MELTDOWN

[noun] - a dangerous situation in a nuclear power station when the material used for power becomes very hot and is likely to explodeA pool of molten fuel would form on the floor of the reactor during a meltdown. [C]An accident at the power station last month brought the system close to meltdown. [U](figurative informal) The last few months have seen the progressive meltdown (= failure) of the country's political system. [U]