On air at 1100GMT: How serious is Japan's nuclear disaster?
You open the newspaper's or see the headlines and it's a terrifying read. Japan has now raised the severity rating of its nuclear crisis to the highest level, the only previous accident to be given a level seven status was the 1986 Chernobyl disaster. However the radiation leakage in Japan is a tenth of that from Chernobyl. It's a confusing picture, not least for the people around the stricken Fukushima plant.
The explanation for the sudden rise is not being put down to a massive escalation in the amount of nuclear being emitted, more that the authorities have examined the data and got a clearer picture of what has gone wrong.
Where it leaves us is less clear. Officials say level seven signifies a "major accident" with "wider consequences" than the previous level. Minoru Oogoda of Japan's Nuclear and Industrial Safety Agency (Nisa), the government's nuclear watchdog said,
"We have upgraded the severity level to seven as the impact of radiation leaks has been widespread from the air, vegetables, tap water and the ocean,"
The Japanese government is going to expand the evacuation zone surrounding the plant, at the same time that new photos of plant before and as the tsunami struck have been released.
Some nuclear experts like Aris Candris, chief executive of Westinghouse Electric, one of the world's largest suppliers of nuclear reactors insists a Chernobyl-style event is technically impossible in a western-designed reactor.
We'll be joined by a nuclear expert to take your questions about the crisis, the significance of the rise to level seven and the implications for people in the surrounding area and beyond. If you have a question for our expert post below.....