The RETRAN code plays an important role in Northeast Utilities’ (NUSCO’s) safety analysis capabilities. Its ability to predict plant response to operational transients has been shown by several benchmarking efforts. Additionally, it has been utilized in performing both design-basis and best-estimate analyses for NUSCO’s operating plants. The decision to use RETRAN as a major contributor to reload analysis efforts at NUSCO was justified by the results of numerous analyses proving RETRAN’s capabilities and credibility.