Nuclear waste experts say the Japanese are literally playing with fire in the way nuclear spent fuel continues to be stored onsite, especially in reactor 4, which contains the most irradiated fuel — 10 times the deadly cesium-137 released during the 1986 Chernobyl nuclear accident. These experts also charge that the NRC is letting this threat fester because acknowledging it would call into question safety at dozens of identically designed nuclear power plants around the U.S., which contain exceedingly higher volumes of spent fuel in similar elevated pools outside of reinforced containment.
Gundersen, who is chief engineer at the consulting firm Fairewinds Associates, added that the spent fuel pool at unit 4 “remains the single biggest concern since about the second week of the accident. It can still create ‘Chernobyl on steroids.'”
http://truth-out.org/news/item/8972-the-worst-yet-to-come?-why-nuclear-experts-are-calling-fukushima-a-ticking-time-bomb