Modernization strategies for scale 6.2

SCALE is a widely used suite of tools for nuclear systems modeling and simulation that provides comprehensive, verified and validated, user-friendly capabilities for criticality safety, reactor physics, radiation shielding, and sensitivity and uncertainty analysis. Since 1980, regulators, industry, and research institutions around the world have used SCALE for nuclear safety analysis and design. However, the underlying architecture of SCALE is based on the original design concept from the late 1970s with dozens of independent functional modules and control programs, primarily implemented in the Fortran programming language, with extensive use of customized intermediate files to control the logical flow of the analysis. Data are passed between individual computational codes using custom binary files that are read from and written to the hard disk. The SCALE modernization plan provides a progression towards SCALE 7, which will provide an object-oriented, parallel-enabled software infrastructure with state-of-the-art methods implemented as reusable components. In realizing this goal, many organizational and infrastructural changes are required, especially related to quality assurance, coordination of efforts across a large team, robust testing strategies to ensure existing capabilities are not disrupted, established of a modern software framework, and finally introduction of advanced features. This paper provides an overview of the strategies of SCALE modernization and details some modernized features available with SCALE 6.2.