A Comparison of the TRITON and ORIGEN2 Source Generation Programs

The Battelle Energy Alliance Research Reactor (BRR) Package has been designed to ship spent high-enriched aluminum-plate fuels from several research reactors. The reactor sites have historically used the ORIGEN2 [1] computer program for generating neutron and gamma source terms. However, ORIGEN2 is an older computer program that is no longer supported by the code developers. In addition, the reactor libraries used with ORIGEN2 are typically developed for low-enriched pressurized water reactors (PWR). To study the accuracy of the source term generated for spent research reactor aluminum plate fuel by ORIGEN2, the source term was regenerated using the TRITON [2] sequence of the SCALE6 code package. TRITON allows a two-dimensional representation of the fuel elements, and generates the data libraries in a problem-specific manner. Using TRITON, the gamma source was similar to the gamma source developed by ORIGEN2. However, the neutron source increased by 1 to 3 orders of magnitude. This paper compares the neutron and gamma source terms for both ORIGEN2 and TRITON, and suggests possible reasons for the differences.