Office for Nuclear Regulation

This website uses non-intrusive cookies to improve your user experience. You can visit our cookie privacy page for more information.

Breach of Security at Sellafield

Information released

ONR holds information that falls within scope of your request. However, this information is being withheld as it falls under the exemption in Section 24 (National Security), Freedom of Information Act 2000.

This is a qualified exemption that is subject to a public interest test. This means that ONR has to balance the public interest factors favouring disclosure against those favouring non-disclosure.

Exemptions applied

Section 24 (National Security), Freedom of Information Act 2000.

PIT (Public Interest Test) if applicable

Factors in favour of release of this information

There is a public interest in Government being as open as possible about matters of civil nuclear security to demonstrate that the regulator is aware of, and dealing with, security breaches.

Factors against release of this information

There is a clear requirement to prevent the disclosure of sensitive information about nuclear security that could assist a person or group planning theft, blackmail, sabotage and other malevolent or illegal acts involving nuclear sites, nuclear material or individuals working on or with those sites and materials.  The requested documents identify weaknesses that would present potential attackers with opportunities to utilise threat vectors that might not otherwise be considered viable.

The public is able to gain information about how civil nuclear security weaknesses are being addressed, but in a sanitised manner, through the annual report (previously the Director Civil Nuclear Security report and in future the Chief Nuclear Inspector report). Information about security improvement activities is presented in a generic manner in the annual report; it avoids identifying vulnerabilities on specific sites but provides assurance that security risks are being regulated and addressed by the duty holder.


On balance, it is not in the public interest to release this information, because disclosure would reveal details about the current procedures that may prejudice national security.