The Rising Influence of Rising Affluence

[OakesCS]

the release of radioactive vapor in Japan would be a particularly sensitive issue.

while undoubtedly true the sensitivity to such things might be a bit over-developed. The wikipedia entry for BWR's says that most of the radioactivity in the steam is due to nitrogen16 which has a half-life of 7 seconds. So while it certainly wouldn't be healthy to be in close proximity to the vent, atmospheric dilution (which will increase as > radius^2) and a very short period of time should reduce the hazard to a negligible level at distances greater than about 600 meters (it's probably negligible at shorter distances but i'm being very generous with windspeeds and half-lives. The decay product is stable oxygen16 so that presents no further hazard).