Probably just a terrorist cell using the cheese grater to break up some yellow cake to make a dirty bomb...
nothing to see here...
Maybe grating medical waste. yikes!
yellowcake contains no Co60, just U and its daughter products.
Co60 has a half-life of a bit more than 5 years, so it is not found in nature ever. It would make an OK dirty bomb, though, because a gram emits lots and lots of gamma in its brief live. yellowcake, though, has a half-live of over 100,000 years, so a gram does not emit much energy at any given time (makes a lousy dirty bomb).
it was probably just on the same container ship that al qeada brought the dirty bomb over on
Actually, there “is” nothing to see here. It is obvious from the fact that the radioactivity is Co60 that some scavengers stole a radiography apparatus from some pipeline construction site and turned it in as scrap metal. It got melted down and incorporated with a bunch of other scrap as cheap steel. It’s happened before in the US, so the problem isn’t unique to China.