Apllication of event tree/fault tree modeling approach to the evaluation of proliferation resistance

With the increasing popularity of nuclear energy as a means to address dwindling fossil resources and generation of greenhouse gases, comes a concern over the potential for increased proliferation of nuclear materials. Newly proposed processes/facilitics will require an efficient, timely, and systematic assessment of the potential for proliferation to support decisions about optimum solutions to these competing concerns. currently, evaluation of proliferation resistance is largely done by experts in an informal and unstructured fashion. As a result the evaluation may not always be repeatable or supportable. In 2002 an expert group was formed by The Generation IV, International Forum to develop an internationally accepted methodology for assessing the proliferation resistance of a nuclear energy system (NES) and its individual elements. A pilot study was performed to test the methodologies being developed. The pilot consisted of assessing proliferation resistance of a specific NES example with each analysis method. The example chosen was called the Example Sodium Fast Reactor which was designed to accept spent sodium-bonded, metallic fuel from four advanced fast reactors and to convert it into new fuel assemblies. A number of different approaches were taken to evaluate the diversion of material from the facility to assess their applicability and usefulness. This paper describes a Decision Event Tree and Fault Tree Analysis approach.