As it happens, my degree is in physics. the majority of high radioactivity elements that you are describing decay within 5 years the remaining waste that stick

As it happens, my degree is in physics. the majority of high radioactivity elements that you are describing decay within 5 years the remaining waste that sticks around for 30k+ years isn't nearly as radioactive. The rods burning off hot radioactive material are not intended to leave the plant and hence I didn't call them out in the waste products. When it comes to low concentrations of radioactive heavy metals like those in spent fuel rods after 5 years the bigger danger tends to be heavy metal poisoning where they are dramatically more toxic than lead.