three mile island

noun

1. an island in the Susquehanna River, near Middletown, Pennsylvania, SE of Harrisburg: scene of a near-disastrous accident at a nuclear plant in 1979 that raised the issue of nuclear-energy safety.

The location of an accident in 1979 in a nuclear power plant — an electrical generator powered by a nuclear reactor — in Pennsylvania. The plant underwent a partial meltdown that resulted in very little leakage of radiation into the atmosphere, panic among nearby residents, losses of billions of dollars, and intense criticism of nuclear power programs in general. (Compare Chernobyl.) The location of an accident in 1979 in a nuclear power plant in Pennsylvania. The plant underwent a partial meltdown that resulted in some radiation leakage into the atmosphere, panic among nearby residents, losses of billions of dollars, and intense criticism of nuclear power programs in general.