The OECD/NEA ROSA Project was performed to resolve issues in thermal-hydraulics analyses relevant to light water reactor (LWR) safety by using the ROSA/LSTF of JAEA for 4 years from April 2005. In particular, it focused on the validation of simulation models and methods for various complex phenomena that may occur during design-basis event (DBE) and beyond-DBE and to increase the level of detail and accuracy in the analyses of the key phenomena during transients and accidents of interest.
This report briefly summarises major findings in all six subjects of the ROSA Project with a description of background and objectives for each subject. Appendices describe new measurement instruments and new test sections furnished for the ROSA Project, and summarise the post-test analyses including answers to a questionnaire on the analysis effort.