Defence Safety and Environment Authority

The DSEA is the authority that is responsible for the regulation of defence safety and environmental protection.


Creation of the Defence Safety and Environment Authority (DSEA) represents implementation of one of the key recommendations of the Haddon Cave report on the loss of Nimrod XV230 in Afghanistan in 2006, which was that, to avoid a conflict of interest, those responsible for the regulation of safety should be independent of those responsible for delivering output. As well as complying with Haddon Cave, creation of the DSEA was endorsed by the Defence Reform report.

MOD has already implemented the principle of regulatory independence in aviation by setting up the Military Aviation Authority (MAA). The DSEA sits alongside the MAA and regulates all other areas of defence where we have exemptions from legislation. These exemptions exist because of the particular needs of defence and cover areas such as nuclear, maritime, explosives and ordnance, and fuels and gases.

The Secretary of State’s health, safety and environmental protection policy statement requires that MOD complies with the law where we are subject to it, and that where we have exemptions we should produce internal regulations that produce outcomes that are, so far as reasonably practical, at least as good as those required by legislation; in addition to regulation, the DSEA is responsible for overarching safety and environmental protection policy and will carry out high level assurance to establish whether TLBs and TFAs are complying with the requirements of legislation, as well as internal regulation, in accordance with the Secretary of State’s policy statement.

Mission statement

The DSEA’s mission is to regulate safety and environmental protection for those conducting defence activity in compliance with the Secretary of State’s policy statement on safety, health, environmental protection and sustainable development. It does this by implementing MOD regulatory regimes in all safety domains outside aviation, producing departmental policy for safety and environmental protection and providing high level assurance on whether defence is meeting statutory and internal regulatory requirements.

Corporate Policy and Assurance Division

The role of the Corporate Policy and Assurance Division is to provide advice on over arching policy and safety environmental protection and to conduct high level assurance on whether MOD is complying with statutory and internal regulatory requirements as detailed by the Secretary of State’s policy statement on safety, health, environmental protection and sustainable development.

The DSEA Corporate Policy and Assurance Division role includes coverage of occupational health and safety, radiological protection, and environmental protection issues, audit/assurance and accident statistical/trends analysis.

The safety role is delivered through Joint Service Publication JSP 375: health and safety handbook.

The radiological protection role is delivered through JSP 392: radiation safety handbook

The environmental protection role is delivered through JSP 418: corporate environmental manual.

The environmental noise role was previously delivered by the Noise Insulation Grant Scheme which was closed in 2005. Information relating to the scheme can be found at: Noise Insulation Grant Scheme (NIGS) in the UK Government Web Archive. NIGS was replaced by the Noise Amelioration Scheme (Military) [NAS(M)] in 2010. Information on NAS(M) can be found at Noise Amelioration Scheme (Military).

The audit/assurance role is delivered via an annual programme to assess TLB and TFA compliance with policy and legislation.

The statistics role is to analyse and spot potential trends in MOD’s accident statistics, and investigate.

Information about the Disposal of munitions at sea can be found in the UK Government Web Archive.

Defence Nuclear Safety Regulator

The Defence Nuclear Safety Regulator (DNSR) was formed in 2006 by the amalgamation of the Chairman of the Naval Nuclear Regulatory Panel and the Nuclear Weapon Regulator. It is one of the MOD regulators brigaded within the DSEA

Nuclear safety in the UK is the subject of a number of pieces of legislation. Among the most significant are the Health and Safety at Work etc Act (1974) and the Nuclear Installations Act (1965 and 1969).

The responsibility for managing activities in a safe manner lies with the operator. In addition, safety is regulated through a system of controls based on a licensing regime required by the NIA. However, there are a number of exemptions relating to activities in the Defence Nuclear Programme (DNP); these can be briefly summarised as operation of nuclear reactors in submarines and design of nuclear weapons.

The Secretary of State for Defence’s policy, requires that where there are exemptions, MOD will introduce standards and management arrangements that produce outcomes that are so far as is reasonably practicable at least as good as those required by legislation. In accordance with this statement, the MOD has set up its own independent regulator of nuclear safety, the Defence Nuclear Safety Regulator (DNSR) to provide MOD regulation particularly where the statutory regulation does not apply.

DNSR operates a regime closely based on the licensing system known as “authorisation”, and it works in close co-operation with the statutory regulator, the Office for Nuclear Regulation (an agency of the Health and Safety Executive) regulating jointly across much of the DNP. DNSR is also the regulatory Competent Authority for the packaging and transport of radioactive materials in the DNP.


Demonstrably safe defence nuclear programmes providing effective, available capability


To regulate the nuclear and radiological safety of the defence nuclear programmes so that they are managed with due regard for the protection of the workforce, the public and the environment


DNSR intends to publish on this website significant documents, relating to its activities as the MOD nuclear safety regulator. This will include policy documents, routine and annual reports resulting from regulatory activity, documents that may be of wider interest (some of these may also have been published via parliamentary processes or been released under Freedom of Information applications) and internal management documents where these will improve the public awareness of our activities.

Defence Nuclear Environment and Safety Board Assurance reports

Contact us

Defence Safety and Environment Authority
Corporate Policy and Assurance
1st Floor, Zone J
Main Building


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