Tepco has announced that the radiation level was not 10 million times higher than normal, but 100,000 times. The Japanese government has criticised their mistake as "absolutely unforgivable". However it seems that the number of millisieverts was correct (1000 mSv), so I don't see what the fuss is all about. They just took the wrong reference for the "normal radiation" level. The fact is that there is no "normal". Firstly, radioactivity varies widely between regions. Then, the radioactivity at a nuclear plant varies even more depending on whether you measure it inside or outside the plant, or a few kilometres away. My point is that "normal" is a fuzzy concept because there isn't just one normal, and the data can be easily tweaked to suit one's interests. I wouldn't be surprised if Tepco was coerced by the government to revise its announcement in order to calm the population after the stir the original announcement made.