Map via BBC
In addition to the danger of a meltdown there is a real danger that the spent fuel rods may causing a criticality accident. To understand just how bad that is consider what would happen if there were a pool fire at the nuclear waste storage facility at the Shearon Harris nuclear power plant as reported by Jeffrey St. Clair,
An October 2000 report from the Sandia Labs in Albuquerque painted a grim picture of the consequences from a pool fire. The report, which was kept under wraps for two years by the NRC, found that a waste pool fire could spread radioactive debris over a 500-mile [805 km] radius, including Cesium-137, a carcinogen linked to birth defects and genetic damage.
I think that there's a real danger that the evacuation zone surrounding the plant will have to become a permanent Exclusion Zone like the one around Chernobyl. I hope I'm wrong about all of this, but things seem to be going very badly right now.