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The requirements of ANSI/ANS 8.1 specify that calculational methods for away-from-reactor criticality safety analysis be validated against experimental measurements. Criticality safety evaluations of spent fuel storage and transportation casks have typically been benchmarked against cold'' critical experiments. This is an acceptable practice where the cask evaluation is conservatively based on fresh fuel isotopics is desired, it is necessary to benchmark computational methods against spent fuel critical configurations. This report summarizes the initial effort to benchmark selected away-from-reactor criticality analysis methods using several configurations from pressurized water reactors (PWR). Beginning-of-cycle (BOC) and end-of-cycle (EOC) reactor configurations have been analyzed. The KENO V.a module of SCALE was used to determine the effective multiplication factor (k{sub eef}) while resonance self-shielding of the cross sections was performed using standard SCALE techniques. In addition, two new pre-processor codes (CONDENSE and LUMPIT) were prepared to simplify the interface between the isotopic prediction codes and the SCALE modules. Two methods were employed to predict the spent fuel isotopics: multidimensional reactor analyses (PDQ7) and point-depletion analyses using both the SAS2 sequence of SCALE and CELL2 code package. To date only the PDQ7 isotopic data have been used to analyze all the configurations. Using the SCALE 27-group cross sectionmore » library, the calculated variance in K{sub eff} is approximately {plus minus}1.5{percent} {Delta}k. Further refinements and additional analyses are currently in progress.« less |
