Office for Nuclear Regulation

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I would like to request a copy of SLP 3.04.06, ‘How do I define MSMLs?’, Issue 4

Date released
26 July 2019
Request number
Release of information under
Freedom of Information Act 2000

Information requested

I would like to request a copy of:

Information released

In response to your request, please find attached a copy of SLP 3.04.06, Issue 4.

Please note that we have redacted some information due to its sensitive nature in line with Section 24; safeguarding national security of the FOIA.

As this is a qualified exemption, we are required to balance the public interest between disclosure and non-disclosure. We have therefore applied the Public Interest Test, as set out below:

Factors for release

The information may provide reassurance to the public about the safety and security of nuclear installations. It may also facilitate the accountability and transparency of ONR for decisions taken by them as a regulator of the nuclear industry. Furthermore, use of the exemption provides no further information to the public and represents a frustration of ONR’s policy of openness and transparency.

Factors for withholding

The information is sensitive as it provides details of locations, facilities, equipment and technical information that has been shared with ONR in confidence, to facilitate our regulatory assessments. This information is judged to be of benefit to hostile and malicious antagonists who may exploit it to identify potential vulnerabilities in the safeguarding of the UK’s national security infrastructure.


In conclusion, after careful consideration of the factors set out above, ONR has concluded that the information should be withheld. This information has been established as sensitive to the safeguarding of national security and shared with ONR in confidence, to facilitate our assessment. Therefore, it is ONR’s judgement that publication of elements of the information requested would not be in the public interest.

Exemptions applied

Section 24

PIT (Public Interest Test) if applicable

Yes, please see above.