Nuclear Criticality Safety

Current R&D Activities

The Nuclear Engineering Division maintains an active R&D program in areas of importance to criticality safety, including the following:

• Participation in several elements of the DOE Nuclear Criticality Safety Program. Argonne contributes to the analytical methods, nuclear data, web-based training module development, preservation of nuclear criticality data, the ICSBEP and the criticality safety web site tasks of the NCSP.
• Development of the stratified source sampling method to improve the reliability of Monte Carlo criticality safety analysis of loosely coupled systems, e.g., stored arrays of weapons pits or spent reactor fuel. The traditional Monte Carlo source iteration algorithm can appear to converge to the wrong eigenvector and a non-conservative eigenvalue when coupling is sufficiently weak.
• Upgrading of cross section preparation methods to exploit recently improved data evaluations. This work includes development of a more accurate Doppler broadening method, improved thinning criteria for redundant energy points, and investigations into more accurate schemes for interpolation in energy and temperature.
• Verification and validation of a variety of cross sections. Comparison of point-wise cross sections from Reich-Moore resonance parameters with corresponding multipole calculations ensures the rigor of the resolved resonance treatment. Benchmarking between ENDF/B-VII.0, JEF-2.2 and experiments is used to validate the two libraries. Participation in Argonne and international benchmark programs with VIM improves the confidence in other codes and libraries.

Last Modified: Mon, February 8, 2010 3:40 PM