Defence Nuclear Safety Regulator (DNSR)

The Defence Nuclear Safety Regulator is responsible for the regulation of nuclear safety across the Defence Nuclear Enterprise.

Who we are

Part of the Defence Safety Authority, the Defence Nuclear Safety Regulator (DNSR) is responsible for regulating the nuclear hazards of the Defence Nuclear Enterprise (DNE) consisting of the Naval Nuclear Propulsion Programme and the Nuclear Weapon Programme, where the Ministry of Defence has specific exemptions from statute: these concern the through-life safety of the Nuclear Reactor Plant and Nuclear Weapon activities.

The arrangements for, and management of, nuclear safety across the Defence Nuclear Enterprise, must meet the exceptionally high standards required by applicable legislation, defence policy and relevant good practice within the nuclear industry.

DNSR consists of a team of Civilian and Naval staff who are predominately nuclear specialist engineers and scientists, supported by a small administrative team. Additionally, DNSR draws on contracted subject matter expertise from Jacobs Regulatory Support Directorate and the Defence Scientific and Technical Laboratory to provide capabilities it is not possible or sensible to permanently retain in-house.

What we do

The DNSR’s primary function is the regulation of nuclear safety across the DNE, holding individuals to account and providing independent assurance of compliance against the Secretary of State for Defence Policy Statement on Health Safety and Environmental Protection which requires that; “Where defence has exemptions, derogations or dis-applications from HS&EP legislation, we maintain Departmental arrangements that produce outcomes that are, so far as reasonably practicable, at least as good as those required by UK legislation. To achieve this, the DNSR aligns our regulation as closely as possible to that of the Office for Nuclear Regulation, deviating only where necessary.


DNSR provides non-prescriptive goal setting regulation, utilising authorisation conditions akin to the civil sectors Licence Conditions augmented by Further Authorisation Conditions (FAC) and Transport Conditions.

Our Regulations

DSA02 – DNSR Defence Nuclear Safety Regulations of the Defence Nuclear Enterprise and DSA03 – DNSR Defence Nuclear Safety Regulations of the Defence Nuclear Enterprise.

Most of Defence Nuclear Safety Regulator staff are Nuclear Inspectors whose working life is spent being the eyes and ears on the ground, examining the arrangements of our regulated community against the regulations which we set and also wider good practice from the Nuclear industry looking for compliance, emergent good practice and continuous improvement.

In addition to examining arrangements we also examine nuclear designs, activities, and permission the transportation of defence nuclear materials and approve the containers utilised.

By working closely with colleagues from the statutory and other defence regulators, we generate benefits for our mutual regulated communities through consistent and joined-up regulation, their interpretation and enforcement.

The DNSR acknowledges key interfaces with the statutory nuclear safety regulator, the Office for Nuclear Regulation and with the environmental regulators, the Environment Agency and Scottish Environmental Protection Agency.

Within defence the DNSR works closely with the Defence Maritime Regulator, the Defence Ordnance and Munitions and Explosives Regulator and the Defence Nuclear Security regulator, recognising the interfaces and dependences between us.


Nuclear capability which is demonstrably safe and available to meet the needs of defence.


To regulate the nuclear hazards of the Defence Nuclear Programme, as a trusted independent regulator in defence.

Contact us

By post:

Defence Safety Authority - Defence Nuclear Safety Regulator
Mail Point #2003
MOD Abbey Wood South
BS34 8JH


Defence Safety Authority

Defence OME Safety Regulator (DOSR)

Defence Maritime Regulator (DMR)

Defence Scientific and Technical laboratory