'Dirty Bombs': Technical Background, Attack Prevention and Response, Issues for Congress [June 24, 2011] [open pdf - 2MB]
"Congress has long sought, through legislation and oversight, to protect the United States against terrorist threats, especially from chemical, biological, radiological, and nuclear (CBRN) weapons. Radiological dispersal devices (RDDs) are one type of CBRN weapon. Explosive-driven 'dirty bombs' are an often-discussed type of RDD, though radioactive material can also be dispersed in other ways. This report provides background for understanding the RDD threat and responses, and presents issues for Congress. Radioactive material is the necessary ingredient for an RDD. This material is composed of atoms that decay, emitting radiation. Some types and amounts of radiation are harmful to human health. […] To address these and related problems, this report provides background on RDDs and issues they raise; it does not track policy actions concerning RDDs in detail. It attempts to help understanding of these weapons in order to aid Congress in its oversight and funding of programs to counter them"
CRS Report for Congress, R41890
Federation of American Scientists: http://www.fas.org/sgp/crs/index.html