As someone who lives between two active nuclear power generating stations, I have given this topic a fair amount of thought.
Everything that I have been told is that the nuclear power that provides warmth, light and thousands of jobs to the local residents is perfectly safe and that the possibility of something going wrong at either of the two plants is minimal.
The residents near Fukushima were probably told the same thing. Also, if there was absolutely nothing to worry about, why did I do emergency drills as a kid and why are there sirens located all around a 5 mile radius of the one that is slightly west of me?
I just want to start by saying that my childhood training of what to do in the event of a nuclear disaster is not going to be very helpful at all. What I was told was to take an iodine pill and hide under my desk. I know that the iodine pill is a good idea because the inert iodine will flood the body and prevent radioactive iodine from collecting in the thyroid, but hiding under a desk is only a tactic that the schools put in place to keep kids from panicking until the buses come to evacuate them to a safer location.
What To Do During a Nuclear Disaster
The first thing that you absolutely need to do in the unlikely event of a nuclear disaster in your town is to NOT PANIC! Panicking is for idiots and people that are doomed to die in stupid accidents. For the rest of us, just stay calm and learn as much as you can about the situation.
There are many different ways that your local government is going to be broadcasting information about the event. Keep your ears and eyes on radio and television, they are the primary forms of communication that is going to tell you what to do. There might also be teams of first responders that will knock on doors to make sure that everyone is aware of the situation. Another method of communication the emergency planners have came up with is the automated telephone system, where a computer with an automated message calls everyone that it call to make them aware of the situation. There are also sirens placed around many nuclear facilities to ensure that the local residents are aware of any possible dangers.
The local officials are most likely going to tell people to remain where they are at first and that the problem at the nuclear reactor is tiny. If this is the case, you are still going to want to keep everyone indoors, including your pets, turn off any air conditioning and furnaces to avoid drawing in any contaminated air and prepare to evacuate if you need to.
If the time has come for you to make a break for it and the local department of emergency plans has instructed everyone to GTFO, then you are going to want to quickly flee to where ever the local evacuation shelters are going to be set up.
Make sure that you bring with you enough clothing and hygiene items. You also are going to want to bring specialty items such as baby food and various things like that. Make sure that you bring identification with you, the last thing that you want is to be responsible for emergency responders dying in radiation while looking for you, when you are safe and sound. You can also consider bringing some canned food and water if you desire, but any evacuation shelter that is set up in a first world country is going to have enough food and water.
If you have never thought of emergency preparation, this a great reason the everyone should have a few days supplies on hand and a bug out bag. Keeping calm and not panicking is going to save your life but making sure the you know how to deal with a nuclear disaster is going probably save the lives of those around you as well.