For related articles and more information, please visit OCA’s Politics and Democracy page and our Health Issues page.

“Fukushima is the biggest industrial catastrophe in the history of mankind,” Arnold Gundersen, a former nuclear industry senior vice president, told Al Jazeera.

Japan’s 9.0 earthquake on March 11 caused a massive tsunami that crippled the cooling systems at the Tokyo Electric Power Company’s (TEPCO) nuclear plant in Fukushima, Japan. It also lead to hydrogen explosions and reactor meltdowns that forced evacuations of those living within a 20km radius of the plant.

Gundersen, a licensed reactor operator with 39 years of nuclear power engineering experience, managing and coordinating projects at 70 nuclear power plants around the US, says the Fukushima nuclear plant likely has more exposed reactor cores than commonly believed.

“Fukushima has three nuclear reactors exposed and four fuel cores exposed,” he said, “You probably have the equivalent of 20 nuclear reactor cores because of the fuel cores, and they are all in desperate need of being cooled, and there is no means to cool them effectively.”