Greater Danger Lies in Spent Fuel Than in Reactors --Electric utility: 11,125 spent fuel rod assemblies were stored at site, about four times as much radioactive material as in reactor cores combined 18 Mar 2011 Years of procrastination in deciding on long-term disposal of highly radioactive fuel rods from nuclear reactors are now coming back to haunt Japanese authorities as they try to control fires and explosions at the stricken Fukushima Daiichi Nuclear Power Station. Japan, like the United States, has kept ever-larger numbers of spent fuel rods in temporary storage pools at the power plants, where they can be guarded with the same security provided for the plants. Figures provided by Tokyo Electric Power on Thursday show that most of the dangerous uranium at the power plant is actually in the spent fuel rods, not the reactor cores themselves.