Office for Nuclear Regulation

2014 update of the Safety Assessment Principles for Nuclear Facilities

This consultation closed on 11 August 2014.


The Safety Assessment Principles (SAPs) provide ONR's inspectors with a framework for making consistent regulatory judgements on nuclear safety cases. The SAPs also provide dutyholders with information on the regulatory principles against which their safety provisions will be judged. However they are not intended or sufficient to be used as design or operational standards, reflecting the non-prescriptive nature of the UK's nuclear regulatory system. In most cases the SAPs are guidance to inspectors, but where guidance refers to legal requirements they can be mandatory depending on the circumstances.

A formal review of ONR's SAPs in 2011 concluded that while no urgent changes were required, the SAPs should nevertheless be updated to reflect both learning from Fukushima and wider changes in the industry since the SAPs were last revised in 2006.

Following extensive work by ONR inspectors, as well as from other regulators and government departments such as the Environment Agency, the Scottish Environment Protection Agency and the Defence Nuclear Safety Regulator, the project to revise the SAPs is now nearing completion, and proposals for an update have been drafted. Recognising that our safety assessment standards are important to the wider nuclear industry, ONR is offering site licence holders, Non-Governmental Organisations and other interested parties an opportunity to comment on our proposals.

We are specifically interested in views on whether the changes adequately address:

  1. learning from the Fukushima accident;
  2. developments in international nuclear safety standards and relevant good practices since 2006.

Public consultation

ONR is therefore inviting comments from interested parties on the proposed revisions to the SAPs.

The proposed updated principles have been split into a number of technical areas to aid the collation of comments.

File name Technical area
Accident Analysis Accident Analysis
ALARP Part 1
ALARP Part 2
Civil Engineering and External Hazards Civil Engineering and External Hazards
Chemical Engineering etc Part 1
Chemical Engineering etc Part 2
Chemical Engineering etc Part 3
Chemical Engineering and Internal hazards
Control Electrical and Instrumentation Control, Electrical and Instrumentation
EP and RP Emergency Preparedness
Radiological Protection and Criticality
Siting Siting
Human Factors Human Factors
LMfS Leadership and Management for Safety
Mechanical Engineering Mechanical Engineering
RWMD Radwaste and Decommissioning
Safety Cases Safety Cases
Structural Integrity Part 1
Structural Integrity Part 2
Structural Integrity
Fundamental Principles and Engineering introduction
Annex on numerical Targets and Legal Limits

The proposed text can be found alongside the existing principles using the links in the table above. The text has not yet been formatted into its final form, so for example, the paragraph numbers from the 2006 SAPs have been retained as a temporary measure. This is to assist the consultation process; the final published version will however have new re-numbered paragraphs. Similarly, new and changed wording is shown in coloured text. The colours used represent different stages in our drafting process and have been retained for our own quality control purposes

How to comment

Anyone wishing to comment on the proposed text should do so using the SAPs external engagement comments form

All comments must be submitted to

As ONR have engaged widely in preparing the updated principles, the external engagement period will last for eight weeks. Comments must be received by 11 August 2014. Late comments are unlikely to be considered.

Next steps

All comments that we receive will be carefully considered.

ONR cannot provide individual responses to comments. However, in accordance with ONR's policy of openness and transparency we are committed to publishing all relevant comments or a summary alongside our responses to them. All the comments included will be anonymised.

An update to the SAPs will be made available on the ONR website later this year. Should you require notification of the revision please register by subscribing to the ONR eBulletin.

This consultation closed on 11 August 2014.