On-Site Inspection for the Comprehensive Test Ban Treaty (CTBT)

Earth crack caused by underground nuclear testing, a diagnostic feature of visual inspection.

The CTBT has been signed by 150 countries including the U.S. where it is awaiting ratification. The treaty protocol provides for verification by several different methods, including on-site inspection (OSI). OSI involves three major technologies for verification: (1) seismic aftershock monitoring, (2) radionuclide measurements, and (3) visual inspection. Among the national laboratories, EES-1 has the lead for development of visual inspection procedures and policies, which will eventually become part of the OSI Operations Manual.

Visual inspection involves both ground-based an overflight components. Of the verification technologies it is the most interdisciplinary and perhaps the most complex, drawing on experience in nuclear weapons testing, geology and geomorphology, oceanography, mining and other industrial activities, and geographical information systems. Since future OSI teams will be composed of personnel of various backgrounds drawn from an international pool, and experience in observing the effects of weapons testing is very rare indeed, developing objective inspection procedures is a great challenge.