Tom Clancy's Sea of Fire (Op-Center #10) by Jeff Rovin

A half-dead Singapore pirate is plucked from the Celebes Sea in the Western Pacific, setting off alarms halfway around the world in Washington, D.C. Traces of radiation are found on the man, causing Australian officials to call in Op-Center for a top-secret investigation of nuclear disposal sites.  When an empty drum from a recent drop-off is discovered near where the pirate's ship was destroyed, the Op-Center team comes to a terrifying conclusion: A multinational corporation hired to dispose of nuclear waste is selling it instead-to a most unlikely terrorist