UK Embassy in Japan: The Difference Between Japanese Crisis and Chernobyl

The UK Embassy in Japan has sent out this message to UK citizens residing in Japan:

It is wholly wrong to compare the situation to Chernobyl, which emitted a radioactive cloud 30,000 feet into the air for a long period of time. In the reasonable worst case scenario at Fukushima, a plume would only be emitted to a maximum height of 500m so any radioactive cloud would land very close to the reactor. A 20km exclusion zone and a further 10km zone where residents are advised to stay indoors would be entirely appropriate for minimising health effects from direct radiation exposure.