Its not likely to be a thousand years before its habitatable again. Long lived isotopes are safer as they are less radioactive and less energetic. And short liv

Its not likely to be a thousand years before its habitatable again. Long lived isotopes are safer as they are less radioactive and less energetic. And short lived isotopes while dangerous are short lived. Its the medium lived that are a problem 70-150 years that are the biggest problem. Secondly we dont have to wait for it to all to be gone just down to a safe background level