X-108B Security Portal

The X-108 Security Portals were manned by security personnel and used as checkpoints for workers, visitors, and equipment entering and exiting controlled areas of the plant site.

The X-108B Security Portal, also known as the North Portal, is one of three remaining original portals that facilitate pedestrian access to controlled areas of PORTS. PORTS was a part of the U.S. Cold War nuclear weapons complex. PORTS’ primary Cold War era mission was the production of highly enriched uranium by the gaseous diffusion process for defense/military purposes.

The X-108B Security Portal is located near the southeast corner of the X-720 Maintenance and Stores building. It is a 4,700-square-foot structure with a small porch facing Knox Avenue and has served as a security checkpoint since its construction in 1955. The portal is no longer manned by security personnel.


Completed in 1955



Building Size

4,700 sq. ft.

Take a Look Inside the Plant

Using our interactive map, you can locate individual buildings within the plant and learn more about its purpose throughout history. Clicking on a building will bring you in-depth information, photos, and videos.

Click Here to See Interactive Map