ON-SITE INSPECTION FOR CTBT VERIFICATION: GROUND-BASED VISUAL OBSERVATION

On-site visual observations will play an essential role in Comprehensive Test Ban Treaty (CTBT) verification. Although seismic and remote sensing techniques are the best understood and most developed methods for detection of evasive testing of nuclear weapons, visual observation can enhance the interpretation of data from these more traditional methods. Not only can visual observation offer "ground truth" in cases of suspicious explosions, but it also can provide accurate source location and testing media properties necessary for detailed analysis of seismic records. For testing in violation of the CTBT, an offending party may attempt to conceal the test, which most likely will be achieved by underground burial. While such concealment may not prevent seismic detection, evidence of test deployment, location, and yield can be disguised. In this light, if a suspect event is detected by seismic or other remote methods, visual observation of the event area is necessary to document any evidence that might support a claim of a treaty violation as well as guide further investigations. However, the methods for visual observation are not widely known nor appreciated, and experience is presently limited. Visual observation can be achieved by simple, non-intrusive means, primarily geological in nature Our work involves compilation of detailed considerations, procedures, and equipment required to field such an investigation.

A well-based understanding of the visual features (Figure 1) of underground testing is first required before inspection can be implemented for clandestine tests. The most extensive experience comes from testing at the Nevada Test Site, the Semipalatinsk Test Site in central Kazakhstan, and Novaya Zemlya. We have reviewed many of the documents regarding visual observation experience at these locations in preparation of a summary report that will serve as background to develop a comprehensive operational manual for visual observation. This operational manual will describe detailed field procedures (Table 1) equipment, and training. Drills and mock inspections are planned to familiarize international participants with the methods of visual observation.

Ground-based visual observation during CTBT on-site inspection involves a series of activities that provide objective information that is basically forensic in character. The equipment approved by the CTBT for ground-based visual observation includes instruments and tools that allow quantification and qualification of observations in a manner that lends itself to data integration. Through data integration, ground-based visual observation information can serve as a basis for planning on-site inspection activities. Ground-based visual observation information will also be integrated with overflight, seismic aftershock, and radionuclide monitoring results to aid in analysis and interpretation (Figure 2). A geographic information system will greatly facilitate information management, analysis, and display. It will provide a method for integrating the data and results from various on-site inspection activities, and with respect to ground-based visual observation, a means to tie together a wide variety of information into a coherent interpretation.

Table 1. Vertical Emplacement Artifacts and Diagnostic Techniques

Collaborators:

• Dennis Barker, Remote Sensing Laboratory, Bechtel Nevada

• Gordon McLeod, Bechtel Nevada

• Paul Rocket, Sandia National Laboratory

Publications:

• Hawkins, W. and Wohletz, K., "Visual inspection for CTBT verification," Los Alamos National Laboratory Report LA-13244-MS, 37 pp, 1997.

• Hawkins, W., Wohletz, K., and Barker, D., "Ground-Based Visual Observation Activities and Data Management: Equipment for the Initial Survey of the Inspection Area," Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), Vienna, 1998.