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Guidance

Summary: the UK’s domestic RN security system

Published 23 September 2026

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This publication is available at https://www.gov.uk/government/publications/domestic-radiological-and-nuclear-security-system/summary-the-uks-domestic-rn-security-system

Summary

The UK Government has well-tested and exercised radiological and nuclear (RN) detection and response capabilities. Together, these capabilities mitigate the risk and impact of a radiological or nuclear attack on the UK. 

Whilst the malicious use of radiological or nuclear materials remains significantly less likely than a conventional attack, the consequences of such an incident would be so serious that we must take steps to mitigate the risk.  

CONTEST 2023, the government’s counter-terrorism strategy, sets out our intention to strengthen nuclear security through investment in modern systems, informed by the latest science and technology, research and international collaboration. 

There has been significant investment by the government in our domestic radiological and nuclear security system to mitigate the risk of an attack using these materials. This investment enables us to consolidate the system, strengthening our domestic radiological and nuclear security capabilities such as border detection (Cyclamen), inland detection, specialist response arrangements and robust preparedness planning.

Layered defence in depth

The domestic RN security system comprises several layers which together provide defence in depth. These layers act to deter, disrupt and mitigate against the threat of the malicious use of RN materials and to keep the UK public safe and secure.

  • Reduce and deter: Reducing the attractiveness of the UK as a target.

  • Detection: Protection from nuclear and radiological threat materials being imported into, moved around, or used at locations within the UK.

  • Specialist response: Specialist response to counter nuclear or radiological threats and devices.

  • Preparedness: Robust plans in place to respond to an attack using radiological or nuclear materials.

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