Overview of ORIGEN2 and ORIGEN-S: Capabilities and limitations

The ORIGEN series of codes are widely used throughout the world for predicting the characteristics of spent reactor fuel and high-level waste. Two independent development activities at Oak Ridge National Laboratory have provided significant enhancements of the original ORIGEN code and yielded the current generation of codes called ORIGEN2 and ORIGEN-S. The ORIGEN2 code was designed to operate as a stand-alone calculational tool with fixed nuclear data libraries. The user selects the library having parameters that best match the specific problem of interest. The ORIGEN-S code was designed to function as a module of the SCALE code system and obtain problem-specific neutronic data through interaction with other modules of the system. ORIGEN-S data libraries created by the SCALE analysis sequence can also be used to run ORIGEN-S in a stand-alone fashion. This paper provides a general overview of the similarities and differences between ORIGEN2 and ORIGEN-S and discusses their capabilities and limitations as exhibited in the characterization of light-water-reactor spent fuel