Now Playing:NULCLEAR DISASTAR LOOMS Japan's nuclear emergency
Description: NULCLEAR DISASTAR LOOMS The earthquake has tested Japan's nuclear industry to its limits.
So far, early fears of a leak, notably at the Fukushima reactor have not materialised. The US Air Force said it had delivered coolant to the power plant.
In all, four sites continue to cause concern. Euronews spoke to Nuclear Safety Expert, Jean Mathieu Rambach.
He told us: ''At the Onagawa power plant there was a fire in the engine room where electricity is produced. At two other sites, Fukushima N1 and N2, there was apparently difficulty in cooling the reactors''