That is incorrect. There are two major groups of elements in spent nuclear fuel: - Actinides (neptunium, plutonium, americium, curium, leftover uranium). Most

That is incorrect. There are two major groups of elements in spent nuclear fuel: - Actinides (neptunium, plutonium, americium, curium, leftover uranium). Most of these materials are fissile or can be bred into fissile materials. Fuel recycling processes reclaim and reuse these elements. - Fission products. These are the lighter elements formed when fuel atoms split apart. Some of the components that are most important from a waste management perspective are strontium 90 and cesium 137. Fission products cannot be used as nuclear fuel. The fission products of greatest concern are also much more toxic than ordinary chemical wastes. The LD50 for arsenic in rats is 15 milligrams per kilogram: https://whs.rocklinusd.org/documents/Science/Lethal_Dose_Table.pdf https://whs.rocklinusd.org/documents/Science/Lethal_Dose_Tab... The LD50 for strontium 90 in hamsters (90 day survival) is 2 millicuries per kilogram: http://www.rrjournal.org/doi/abs/10.2307/3573895 http://www.rrjournal.org/doi/abs/10.2307/3573895 Given strontium 90's specific activity of 142 curies/gram (https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19680020487.pdf https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/196800...), in mass terms that's 14 micrograms per kilogram for the LD50. Gram for gram, strontium 90 is about 1000 times as acutely deadly as arsenic, or three times as acutely deadly as the nerve gas sarin. There are few industrial chemicals that have toxicity comparable to or greater than nerve gas, and they (like spent nuclear fuel) have special regulations and require special handling.