This report examines the legislation and oversight by Congress 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 also provides background for understanding the RDD threat and responses.

This report raises several issues for Congress, Including: (I) the priority for countering RDDs vs other CBRN, (II) how to improve radio logical forensics capability, (III) whether to modify certain personnel reliability standards etc.