[Nyororin]

Okay, regardless of reasons or methods of their calculation, 7 is 7.

The question was "Why from a 5 to a 7 with no 6?" - It was because they combined several 5s into one event which went over the line for 7. No debate about calculation from me. I was just explaining why they revised the rating straight up to 7.

All that Chernobyl and Fukushima have in common is that number now.. 7. The actual radiation levels and containment of the situation are still light years apart. Fukushima and Chernobyl are still not comparable. Only sensationalists are using that comparison to shamelessly draw more attention to their stories. It is really getting despicable, and I really wish they could all take the place of the many children who were washed away in the tsunami.

Basically, this. The status has not changed. They just updated the previous rating based on more detailed information and combining all the events into one.
Everything over a certain point is a 7. It doesn`t matter how far over a certain point. On the scale both a 7 and a 20 would be a 7. There is no higher number. Going over the line to make it a 7 doesn`t mean it is equal to Chernobyl. It just means that it, like Chernobyl, went over the same line. How far over that line doesn`t matter. It could be 1 over the line, or it could be 10 times Chernobyl... And it would still be rated with the same number.
Better to actually look at data to make a real comparison.

In terms of the current situation - things haven`t changed significantly, and they`re just keeping it somewhat stable without managing to get much improvement. They`re concerned that if they cannot improve the situation at a better pace, there is a chance that it may continue to slowly release radiation that would add up to Chernobyl levels. In other words, "We are screwed at this rate - help! Before things get really bad - help!"

we have been told that the spead of radiation is now on scale with the chernobyl disaster.

Spread, yes. Levels, no. Despite the fears and concerns for the future, at this point there has only been a relatively slow release of less than 10% what was released at Chernobyl. The size of the area that has shown a rise in radiation is similar to the size of the area showing a rise after Chernobyl. The levels that have been measured are much lower though.