The Civil Nuclear Constabulary (CNC) is a special police force responsible for providing law enforcement and security at any relevant nuclear site and for security of nuclear materials in transit within the United Kingdom.
The CNC was established on 1 April 2005, replacing the former Atomic Energy Authority Constabulary established in 1955.
The CNC does not guard the United Kingdom's nuclear weapons; this role is the responsibility of the British Armed Forces and the Ministry of Defence Police.