Table 1: NPP reactor accidents with INES level 5, reactor age denotes time since grid connection.

INES level Reactor location Reactor type Year of  (age at) accident Description of damage 5 Three Mile Island, USA 1 PWR 1979 (11 m) Severe damage to the reactor core 7 Chornobyl, Ukraine 1 RBMK-100 1986 (2 yr 4 m) Widespread health and, environmental effects, external release of a significant fraction of reactor core inventory 7 Fukushima-Daiichi, Japan 4 BWR 2011 (33–40 yr) Like Chornobyl