Cassini nuclear risk analysis with SPARRC

The nuclear risk analysis of the Cassini mission is one of the most comprehensive risk analyses ever conducted for a space nuclear mission. The complexity of postulated accident scenarios and source term definitions, from launch to Earth swingby, has necessitated an extensive series of analyses in order to provide best-estimates of potential consequence results and bounding uncertainty intervals. The Space Accident Radiological Release and Consequence (SPARRC) family of codes, developed by Lockheed Martin to analyze polydispersed source terms and a combination of different atmospheric transport patterns, have been used for the Cassini Final Safety Analysis Report (FSAR). By identifying dominant contributors, the nuclear risk of each mission segment is understood with a high level of confidence. This paper provides the overall analysis process and insights developed from the risk analysis.