Observations on physical protection methods for protecting against unauthorized acts by an insider

Two basic approaches have evolved over the past several years for physical protection against sabotage by insiders. One, area-type physical protection, involves the use of access controls at area boundaries. Current practices at nuclear power plants generally fall into this category. The second, component-level physical protection, involves hardware at individual components as well as access controls at the boundary. The area-type physical protection concepts include team, area, and operational zoning. Team zoning requires the formation of multiperson teams that must be used to gain access to vital areas. Area zoning divides the plant into two or more zones, each of which is operated and maintained by separate, dedicated teams. Operational zoning is a closed-loop access control system that permits an initial vital area access, but blocks access to certain other vital areas until the operability of equipment in the first area is verified by test or inspection. Component-level physical protection is also a closed-loop system in which both area and component access are monitored. Each of the above measures can provide effective protection against an insider in certain instances, but each has weaknesses that must be recognized. An approach for protection against the insider is to take the most promising features of each of the above physical protection measures and supplement these capabilities with damage control and design changes as appropriate for a particular plant