VISA-2: A General, vulnerability-Oriented Method for Evaluating the Performance of integrated Safeguards/Security Systems at Nuclear Facilities

The VISA (Vulnerability of Integrated Safeguards Analysis) method, developed in 1976-77 for the Nuclear Regulatory Commission, has been adapted to a broader range of uses. The 1977 VISA method is a general conceptual approach, designed top-down, for evaluating the performance of integrated safeguards/security systems against a range of threats. The 1977 description of VISA implied use of computer modeling and simulation. The method has been adapted for use with other types of analysis, including subjective judgements of individual experts and consensus judgements arising from gaming exercises. In addition, some computerized analysis methods developed during recent years for evaluating parts of a safeguards/security system against certain threats can be used as part of a VISA evaluation of integrated system performance against a full range of threats. The protection systems included in an evaluation are physical protection, material control, material accounting and consequence mitigation systems. The performance of these systems is evaluated in terms of how they perform as an integrated safeguards/security system. The resulting method has been designated VISA-2.