> The most dangerous ones are generally those that have half-lives of days or weeks. That is long enough to get into a human body and give out a lot of it's energy. The is particularly the case for elements that are readily absorbed by the human body (such as strontium which replace calcium IIRC).
You're mistaken, the most dangerous waste is that with half lives measured in decades, like cesium-137 or strontium-90 which both have half lives of about 30 years. That 30 year half life means that it can take centuries for the waste to decay away to safe levels. More than hot enough to kill, and with the longevity to do so for several generations. Strontium-85 and strontium-89 half half lives measured in tens of days, but after a few years you don't have to worry about those anymore. It's the isotopes like strontium-90 that are the major concern.
You're mistaken, the most dangerous waste is that with half lives measured in decades, like cesium-137 or strontium-90 which both have half lives of about 30 years. That 30 year half life means that it can take centuries for the waste to decay away to safe levels. More than hot enough to kill, and with the longevity to do so for several generations. Strontium-85 and strontium-89 half half lives measured in tens of days, but after a few years you don't have to worry about those anymore. It's the isotopes like strontium-90 that are the major concern.