Chernobyl is now not anymore reactive than new York city...plus there were multiple reactors there and even after the melt down workers still stayed at the other sites which were in buildings right next doors.
Just wanted to mention this because I've been doing some research on it lately and found that Chernobyl wasn't nearly as bad as everyone thought. Only ~50 people died from any related affects of this incident...not 1000s and 1000s like many tend to believe.
I would assume the know or could calculate the density of this material and then estimate the size/volume and then, there you go, you can now find the mass ;)
Just wanted to mention this because I've been doing some research on it lately and found that Chernobyl wasn't nearly as bad as everyone thought. Only ~50 people died from any related affects of this incident...not 1000s and 1000s like many tend to believe.
All i hope is that it still doesn't exist