I don’t know what to say about the disaster striking Japan. The size of the earthquake (now being reported as a 9.0) was tremendous, one of the largest earthquakes ever, and the following tsunami overwhelmed even one the countries best prepared for tsunamis.
The focus now is on the nuclear plants that are in partial meltdown. There is a lot of fear out there, and some of the coverage has been hyperbolic. The situation is still unstable, and it could of course get a lot worse from here.
As someone who supports nuclear power, who is a scientist, and who has been trained in radiological disaster management, I have to ask myself if these events would change my views, and I would have to say so far, no. I do think there could have been more done at the plants for saftey backups (e.g., the ability to run a backup turbine off the decay heat to power the cooling pumps), and that a safer (in my non-specialist and Canadian opinion) CANDU design probably should have been used in a seismically active country like Japan. But, nuclear power is one of the few options to meet the power requirements of the world, and especially countries like Japan, with high population densities and few hydroelectric options.
Plus, I think it’s important to keep in mind the scope of the problem so far. First off, this is not a separate nuclear power problem, this is a result and an extension of the one of the worst earthquakes and tsunamis ever. This is the worst-case scenario for these reactors, and these are old reactors. The death toll from the earthquake and tsunami are still being tallied, but are in the several thousand range. There are workers in the plants that will likely have health effects from radiation exposure (unclear how many at this point), but most of the general public near the plant was evacuated days ago. Radiation has been released into the environment, with the highest numbers I’ve seen peaking at 12 mSv/hr close to the plant, but generally much lower than that. A typical background dose is in the range of a few mSv per year, and a CT scan might be several mSv. The Canadian occupational limits are 20 mSv/year. So even close to the plant, a person could take their sweet time evacuating and still have no health effects.
What the ultimate outcome will be is still an open question, and it will take several days until the decay heat from the cores is gone and any further fire/explosion/breach risk dissipates. However, the actual impact of the nuclear disaster looks like it will pale in comparison to the impact of the tsunami and earthquake natural part of the disaster. Yet, already the fear is enough to compromise the development of nuclear plants around the world.
I know there must be burning questions out there, ask away and I’ll try to answer them!