Why test unless you're worried about the contents (that they supposedly didn't have) within the structures?
Some will interpet this a Saddam believing that the US used weapons that contains nuclear radiation or biological weapons against the palaces, but knowing that Saddam made was ready to be bombed in 1998 to prevent the UN WMD inspectors from searching the Presidential palaces for WMD, and he got bombed indeed, then this document carry a lot of importance.