Chernobyl and Fukushima: What the Two Level 7 Accidents Changed

Only two accidents have reached INES level 7, the maximum on the international scale. Chernobyl in 1986 destroyed a reactor with design flaws and a flawed test, while Fukushima Daiichi in 2011 lost three cores to a tsunami far beyond its design basis.

Both forced evacuations and global reform. After Fukushima, Japan idled its whole fleet, Germany voted to phase out nuclear, and every operator worldwide added backup power and venting.

Public attitudes and plant designs diverged, with several countries now reversing course back toward reactors..