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by the NFCC


High-security features

Hazard Knowledge

Utility and fuel sites across the UK form a part of the critical national infrastructure (CNI) and as such they are protected to a very high level. All CNI sites will have a risk-assessed level of intruder detection and protection.

Security features may make entry to a site problematic or hazardous; close liaison with the site operator will be required.

Active nuclear and first-stage decommissioning sites will have armed Civil Nuclear Constabulary protection and a wide range of personnel and vehicle mitigation measures; entry will be escorted at all times.

Site-Specific Risk Information (SSRI) may contain details of security features such as:

  • High fencing with barbed wire or razor wire
  • Electrified fencing
  • Anti-climbing guards on transmission towers and poles
  • High walls
  • Armed on-site protection

Entry to an electrical installation, such as a substation, can only be achieved following confirmation from the relevant distribution network operator (DNO) that the area is safe to enter.

Electrical installations will have signage detailing hazards and contact details on access points to the sites, as well as danger of death signs around their perimeters.


Figure 9: Substation access door (also showing SF6 warning sign) - photograph courtesy of Peter Martin