This information comes from a Japanese scientist who may or may not have to attend the power plant of Fukushima to help with the current situation:
* In case of a ‘reasonable worst case scenario’ (defined as total meltdown of one reactor with subsequent radioactive explosion) an exclusion zone of 30 km would be the maximum required to avoid affecting peoples’ health. Even in a worse situation (loss of two or more reactors) it is unlikely that the damage would be significantly more than that caused by the loss of a single reactor.
* The current 20km exclusion zone is appropriate for the levels of radiation/risk currently experienced, and if the pouring of sea water can be maintained to cool the reactors, the likelihood of a major incident should be avoided. A further large quake with tsunami could lead to the suspension of the current cooling operations, leading to the above scenario.
* The bottom line is that these experts do not see there being a possibility of a health problem for residents in Tokyo. The radiation levels would need to be hundreds of times higher than current to cause the possibility for health issues, and that, in their opinion, is not going to happen (they were talking minimum levels affecting pregnant women and children – for normal adults the levels would need to be much higher still).
* The experts do not consider the wind direction to be material. They say Tokyo is too far away to be materially affected.
* If the pouring of water can be maintained the situation should be much improved in time, as the reactors’ cores cool down.
* Information being provided by Japanese authorities is being independently monitored by a number of organizations and is deemed to be accurate, as far as measures of radioactivity levels are concerned.
* This is a very different situation from Chernobyl, where the reactor went into meltdown and the encasement, which exploded, was left to burn for weeks without any control. Even with Chernobyl, an exclusion zone of 30 km would have been adequate to protect human health. The problem was that most people became sick from eating contaminated food, crops, milk and water in the region for years afterward, as no attempt was made to measure radioactivity levels in the food supply at that time or warn people of the dangers. The secrecy over the Chernobyl explosion is in contrast to the very public coverage of the Fukushima crisis.
More international coverage:
and some more images from today about the radiation levels:
More Fukushima radiation News in English:
Japan Ministry of Education, Culture, Sports, Science and Technology release more data about radiation levels:
make sure to read the English files 😉
The best piece I have read so far about what is going on at Fukushima:
Radiation level calculator:
A video about Japanese day laborers in Japanese power plants