The common perception of the current situation
Imagine you have a very long alley, just wider than a car, and it's filled with little children innocently playing. A muscle car with bull horns on the front (and barbed wire stretched between them) is about to burn down that alley at 150 mph. It cannot slow down or crash or turn for some reason which I don't know, but it just is, and it's going to mow down anybody that gets in its way without even taking a dent. Even the kids at the other end of the alley aren't going to have time to get out of its way. The only thing stopping it is one man with his foot on the brake pedal, but he's getting real tired and the brakes aren't very strong, so it could speed off at any second. It's going to be a disaster.
What's actually happening
The same car is stopped at the end of the same alley. The engine is idling. The bulk of the fuel has been removed, but there's still dregs left in the fuel tank and pipes so it's going to take a little while for it to run out of fuel. The handbrake is on. And a man is sat in the drivers seat with his foot on the brake. He's getting tired. They're trying to encourage him to stick at it, but it's uncertain if he can keep it pushed down before the engine runs dry and stops by itself. If he dozes off and releases the brake, and the handbrake fails, and nobody else can get to the main brake fast enough, the car will slowly career into a concrete wall that was designed to stop the same car hitting it at 500mph. Just to be extra sure, they've asked the kids to go home to mum until it's sorted.
Fear mongering in the western media and blogs is not helping families who are already distressed (with good reason) worrying (also with good reason) about loved ones in Japan. Please instead consider donating to one of the many organisations providing relief efforts. Please also note that this is in no way meant to imply the current situation isn't dangerous – it is extremely dangerous in the immediate area and the people who are in the most danger at Fukushima are the plant operators who are working tirelessly (and thanklessly) putting their lives on the line to ensure everybody else's safety.