I don't know that there is a technical definition of a nuclear disaster. There are two accidents that are commonly referred to as disasters. One is the well known Chernobyl disaster, and the other is the Kyshtym disaster, both of which were in the former USSR. The Windscale fire, Three Mile Island Accident, and other problems are referred to as accidents.
There is an International Nuclear Event Scale, which rates events on a scale of 1 (least important) to 7 (most important). On this scale, the Chernobyl Disaster is rated at a 7, and the Kyshtym Disaster is rated at 6. Three Mile Island Accident is rated at 5, as is the Windscale Fire, and two other accidents.
There is a link below to an article on the International Nuclear Event Scale.
International Luxembourg Forum on Preventing Nuclear Catastrophe was created in 2007.
Bett Pohnka has written: 'The nuclear catastrophe'
Catastrophe means : a disastrous end, bringing overthrow or ruin. Any great and sudden calamity, disaster, or misfortune. The sinking of the Titanic was a catastrophe for the shipping industry. The catastrophe in Chernobyl Russia was caused by a nuclear meltdown.
Aftermath of Nagasaki and Hiroshima showed the power and catastrophe of the explosion. Too powerful and inhumane to drop on anyone.
Only the use of a nuclear bomb would be considered a catastrophe. The development of nuclear weapons can be ill-advised, can be costly, can raise tensions and increase the likelihood that one will be used, but is not itself catastrophic.
a huge catastrophe
No, catastrophe is a noun.
In "There Will Come Soft Rains" by Ray Bradbury, the initial catastrophe is a nuclear war that wipes out humanity and leaves the fully automated house standing as the only remnant of civilization. The house continues to function on its own despite the absence of its inhabitants.
Japan suffered a devastating earthquake and tsunami in March 2011. Following this, a nuclear disaster occurred at the Fukushima Daiichi nuclear power plant due to damage caused by the natural disasters.
The earthquake in China was a major catastrophe.
'Catastrophe' has four syllables.
U-Catastrophe was created in 2007.