Code to Code Comparison of One- and Two-Dimensional Methods

This calculation file provides comparisons of one- and two-dimensional methods for calculating the isotopic content of spent nuclear fuel. The one-dimensional methods use the SAS2H sequence of SCALE 4.4a (Reference 7.1) and the SAS2 sequence of SCALE 5.0 (Reference 7.2). The two-dimensional method uses the TRITON control module along with the T-DEPL sequence of SCALE 5.0 (Reference 7.3). The SAS2H results for SCALE 4.4a are taken from Reference 7.4. Data from previous two-dimensional calculations (Reference 7.5) using CASM03 will also be used for comparisons with TRITON. The objective of these comparisons is threefold in nature: [1] to determine the accuracy of each computer code sequence in predicting the isotopic concentrations of spent nuclear fuel, [2] to identify modeling approaches that may affect each code's ability to produce accurate results, and [3] to quantify the overall effect that these modeling approaches have on calculated reactivity.
The purpose of this calculation is achieved through considering 3 sets of comparisons. These include comparing:
• boiling water reactor (BWR) radiochemical assay (RCA) data with one- and two-dimensional calculation methods
• one- and two-dimensional depletion calculations for a similar fuel assembly (i.e., to the RCA data assembly) from a BWR commercial reactor criticality (CRC) evaluation (References 7.5 and 7.6)
• one- and two-dimensional depletion calculations for a pressurized water reactor (PWR) fuel assembly at 2.5 wt% 235U from the PWR Isotopic Database.