The operational patrol unit of the Civil Nuclear Constabulary (CNC), responsible for security at the Dounreay nuclear facility in Scotland, has successfully completed its largest regulatory compliance assessment exercise to date — the Regulatory Evaluation Demonstration Exercise (REDE). This exercise is conducted to verify the readiness of security forces to respond to various scenarios and ensure compliance with established standards. Following the exercise, the independent regulator — the UK Office for Nuclear Regulation (ONR) — awarded the results an 'adequate' rating. This assessment confirms that personnel and safety procedures at the facility meet the necessary requirements to ensure protection of the nuclear site. Dounreay is one of Scotland's key nuclear facilities, which previously housed a research reactor and is currently undergoing decommissioning operations and management of radioactive materials. The safety of such facilities is particularly important due to potential risks associated with nuclear materials, and regular readiness assessments of security units are an important part of the control system. Successful completion of the REDE demonstrates the effectiveness of CNC staff training and confirms the organization's ability to respond to potential security threats to the facility. Such exercises typically include practising various scenarios, including responses to perimeter breaches and other potential incidents, enabling the organization to maintain high levels of personnel readiness.