Reed, Davis Allan | Search NASA

DOE OSTI2011

Application Areas of Potential Challenge to Nuclear Criticality Safety Margins for Future High Temperature Gas Reactor Fuel Cycle Activities

Fuel cycle activities for future high temperature gas reactors (HTGRs) will involve uranium enrichments and fissile material configurations that differ significantly from those of current light water reactor (LWR) fuel cycle activities. LWR fuel cycle activities are supported by a wealth of applicable critical experiment benchmarks that allow margins of subcriticality to be well-defined. In contrast, few critical experiments are clearly applicable to several portions of the HTGR fuel cycle. This work identifies HTGR fuel cycle activities presenting potential concern for reliable demonstration of an adequate margin of subcriticality. Recommendations are developed to address these areas of concern.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2011

Scale/TSUNAMI Sensitivity Data for ICSBEP Evaluations

The Tools for Sensitivity and Uncertainty Analysis Methodology Implementation (TSUNAMI) software developed at Oak Ridge National Laboratory (ORNL) as part of the Scale code system provide unique methods for code validation, gap analysis, and experiment design. For TSUNAMI analysis, sensitivity data are generated for each application and each existing or proposed experiment used in the assessment. The validation of diverse sets of applications requires potentially thousands of data files to be maintained and organized by the user, and a growing number of these files are available through the International Handbook of Evaluated Criticality Safety Benchmark Experiments (IHECSBE) distributed through the International Criticality Safety Benchmark Evaluation Program (ICSBEP). To facilitate the use of the IHECSBE benchmarks in rigorous TSUNAMI validation and gap analysis techniques, ORNL generated SCALE/TSUNAMI sensitivity data files (SDFs) for several hundred benchmarks for distribution with the IHECSBE. For the 2010 edition of IHECSBE, the sensitivity data were generated using 238-group cross-section data based on ENDF/B-VII.0 for 494 benchmark experiments. Additionally, ORNL has developed a quality assurance procedure to guide the generation of Scale inputs and sensitivity data, as well as a graphical user interface to facilitate the use of sensitivity data in identifying experiments and applying them in validation studies.

99 GENERAL AND MISCELLANEOUS↗