Improving Sensitivity in the NNSS COMPASS Model

Abstract

The Comprehensive Analysis of Safeguards Strategies model, COMPASS, was initially implemented with the goal of eliminating functions and requirements that did not contribute to the MC&A program at the particular site. The model sub-elements were revised several times through additions and deletions as the process was better understood. Contributions and ratings were developed and implemented. Because of the original intent, the process left the contribution factors closely grouped toward the top of the range. The effect of this is a flat sensitivity; a change in any element and sub-element affected the system effectiveness to the same degree no matter which one changed. This paper describes a method for determining element and sub-element contributions so that changes in element effectiveness are more accurately reflected in the overall system effectiveness.