While any release of radiation into the environment is dangerous, Carnegie's James Acton, speaking on Fox News, said that if the leak in Japan's Fukushima nuclear power plant and other plants do not get any worse, there is unlikely to be any serious repercussions for the local people or environment. However, Acton warns, if the cooling systems do not succeed in bringing down temperatures, the nuclear fuel could start to melt, causing a major nuclear accident.

Acton described how a series of accidents of the earthquake have created radiation leaks.  Describing the worst case scenario, Acton warned that if the cooling pumps cannot be powered, the steam coming from water intended to cool the nuclear core could become highly radioactive, with severe consequences.