A few thoughts regarding the scale of destruction caused by natural disaster in Japan, and the hews headlines which are almost exclusively about the nuclear reactor leakages.
There is a perception that you don't need to make news about the impact of the tsunami in Japan, because "nothing can be done about a tsunami".
That is not true. A lot can be done about a tsunami. And in fact, a lot was done in Japan. Warning systems, evacuation plans, protective structures. That's why the number of dead will be around 30,000 and not 300,000 or more. When Indonesia and Thailand were hit by a tsunami a few years back, a lot more people were killed because they had not prepared as well.
Likewise with nuclear power. The plants can be improved. In fact, besides Fukushima, several other nuclear plants on the same coast were hit by this huge tsunami - and there is no crisis. Some of them needed to resort to emergency procedures, but those were successful. We should learn about that.
What actually scares me about the Fukushima incident is people like Frigyes Reisch, head of Swedish nuclear safety, says he thinks "in Sweden it would be handled more effectively". That sounds actually scary and overconfident. You don't make nuclear plants safer by pretending that you are more effective and better than the Japanese. That's a recipe for disaster. The way to avoid trouble is that you plan ahead for all kinds of risks and make contingency plans, back-up systems, better design. You don't jsut assume that you are more efficient than the Japanese.
If you are asking why there are problems in Swedish reactors, I think the biggest reason is the rather foolish referendum 30 years ago where there was a decision to shut down the plants in Sweden. Which was unrealistic, couldn't be done, and wasn't done, because the nation needs electricity. Instead, the utilization of the plants has increased, without much investment.
Why? If you are going to shut down the plants, the owner cannot invest in further development and renewals. And these are the things that would introduce new safety features, better reactor designs, safer plants. So Sweden voted to increase nuclear power but not develop it to be safer.
Otherwise, I'm quite shocked by the way media in the Nordics are exploiting the Japanese disaster politically to oppose nuclear power. There is a huge humanitarian disaster there. Even though the Japanese did prepare well, there was still huge damage and a lot of loss of life due to tsunami. The crisis in Fukushima plant is a very minor issue compared to the direct impact of the tsunami itself, even despite the extensive preparations and evacuations. The life has been changed for millions. But all that has gone from headlines, because fearmongering about nuclear plants sells better.
Some basic information:
http://online.kitp.ucsb.edu/online/plecture/bmonreal11/ (from March 16)