Emotional outburst (8)
I believe the answer is:
meltdown
(Other definitions for meltdown that I've seen before include "Disastrous event as to overheated nuclear reactor" , "Disastrous collapse - nuclear accident" , "Sudden disastrous failure (of nuclear reactor)" , "Disastrous overheating of core of nuclear reactor" , "Disastrous event like overheating of nuclear reactor as in Chernobyl" .)