Office for Nuclear Regulation

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Copies of the Symptom-Based Emergency Response guidelines (SBERG) and Severe Accident Guidelines (SAG)

Information released

ONR does not hold a copy of the SBERG document, but we do hold the SAG. However, this information is being withheld as it falls under the exception in Regulation 12(5) (a) (National Security), Environmental Information Regulations 2004.

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


The SBERGs for the Advanced Gas Cooled Reactors are held by EDF Nuclear Generation Ltd and those for Magnox reactors by Magnox Ltd. To request copies of these documents please contact these organisations directly."

Exemptions applied

Regulation 12 (5) (a).

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 the handling of severe nuclear accidents. 

Factors against release of this information

There is a clear requirement to prevent the disclosure of sensitive information about procedures for handling nuclear accidents that could assist a person or group planning sabotage and other malevolent or illegal acts involving nuclear sites, nuclear material or individuals working on or with those sites and materials.


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.