Alcohol itself is considered a drug and can be addictive.
However abusing alcohol is not equal to being an addicted.
Alcohol abuse is therefore considered heavily drinking.
A person who abuses alcohol is a heavy drinker, which normally exceed the amount he or she could drink regardless of the consequences of it.
A person who abuses alcohol might become an addicted but the difference is that an addicted will drink alcohol in a regular basis or can not leave without it, while the alcohol abuser will be one person that looses control of the amount he drinks.
What causes Nuclear Disaster is when the atoms when they split the energy is to great and it can no longer be controlled. One that occurs radiation leaks out into the air and goes on for miles. Killing all living organisms. Or if the people survive they have permanent injuries such as cancer.