Joe AutoDrill wrote:
http://www.ornl.gov/~webworks/cppr/y2001/rpt/111879.pdf

Amazingly similar.

The steel made sense before, but I've never known mercury to be
identified as a particle absorbing material. I think that in this case,
I'll be very NIMBY until someone could explain how the used mercury
would be immobilized... Perhaps in a borosilicate glass like nuke
wastes... Or they could sell it as surplus to Red China, and they could
use it in thermometers.

Read them in the dark...