I dealt with spent nuc materials when I was in the heavy equipment business.
All's well as long as some asshole doesn't get careless.
A case in point:
We had some transporters at the DuPont plant in Oakridge, TN.
Brake failures occurred.
We went to look. That was a tedious undertaking!
We got radiation tags, respirators. All's well until we found the decontam crew didn't flush the brake dust prior to us opening them up.

The tech got the dust on his hands and that triggered the response.
They shaved him absolutely bald, cut his nails to the quick, irrigated his eyes, ears, nose.
Gave him several showers with a check between each.
They then confiscated his truck, tools, clothes, and everything else he had on him.
He reported to their med team every 30 days for a yr!
All this was due to being lazy.
The equipment was handling 55g barrels of dirty water. The barrels were outside and leaked.
All had to be pumped into safe containers.
Here's an example of being careless with that shit!