The National Nuclear Security Administration has seven sites that possess Category I special
nuclear material (SNM), which requires the highest level of protection under the Department of
Energy's Design Basis Threat (DBT) policy. The DBT policy reflects the most credible threats to
Departmental assets and operations. In May 2003, the Department revised the DBT to reflect the
threat environment existing after the attacks of September 1 1,2001, including terrorism.
Changes to site protection programs to implement the 2003 DBT were to be completed by the
end of Fiscal Year (FY) 2006.