The United Kingdom Atomic Energy Authority Constabulary (UKAEAC) was formed in 1954 under the provisions of the Atomic Energy Authority Act with its job being to protect nuclear material both on United Kingdom Atomic Energy Authority (UKAEA) sites and in transit. Further legislation extended UKAEAC jurisdiction to British Nuclear Fuels Limited (BNFL) and URENCO sites. On the 1st April 2005 as directed by Chapter 3 sections 51 - 71 of the Energy Act 2004 the UKAEAC became the Civil Nuclear Constabulary (CNC).

The Constabulary is unique in mainland Britain in that all its officers are authorised to use firearms to protect nuclear material (Authorised Firearms Officers in other UK Police services are only authorised to use firearms to protect human life). Officers of the CNC are trained to the same high standards as police officers in county police services, with the addition of advanced training in the use of firearms. At each of the sites that fall within CNC jurisdiction, CNC officers try to maintain a close working relationship with their opposite numbers in the local police service. The CNC currently has a strength of around 500 Officers based throughout England and Scotland. The CNC is accountable to Parliament through the Department of Trade and Industry via a police authority.

According to its Chief Constable, the CNC has the following aims:

• To provide appropriate security for nuclear material, both on site and during transit, nationally and internationally, in accordance with customer requirements and particularly with appropriate national and international standards.

• To maintain a secure environment within which the work of all individuals and groups operating within our area of jurisdiction can be carried forward.

• To provide an efficient and cost-effective general police service.