The droplet entrainment in horizontal flow in water-cooled nuclear reactor plays an important role in many transients such as IB-LOCA and LB-LOCA. A benchmark of system thermal-hydraulic (SYS-TH) codes capabilities to predicting the onset of droplet entrainment and entrainment rate was conducted within FONESYS. FONESYS is a network among code developers who share the common objective to strengthen current technology, to highlight the capabilities and the robustness as well as the limitations of current SYS-TH codes to predict the main phenomena during transient scenarios in nuclear reactors for safety issues. Mantilla performed 49 air-water tests with the 2-inch test section and 19 tests with the 6-inch test section at low pressure and temperature. Tests were selected aiming to support and complement an on-going activity on the scalability of codes’ closure laws, currently focusing on the horizontal stratification criteria and the onset of droplet entrainment and entrainment fraction criteria. Focus was put on the capability of ATHLET, CATHARE3, MARS-KS, RELAP5, RELAP5-3D, SPACE and TRACE in predicting the onset of droplet entrainment, the entrainment rate and pressure drops. Overall benchmark results show some spread in the results calculated by codes, highlighting the need for further research and development. Improving the capability in predicting dispersed flows might be beneficial for the analyses of different LOCA scenarios. The scalability of closure laws is discussed and possible ways for improving them are suggested.
Droplet Entrainment Prediction in Horizontal Flow by Sys-Th Codes - Mantilla Experiments - Recent Analyses Made within the FONESYS Network
D’Auria Francesco
Conceptualization
;
2022-01-01
Abstract
The droplet entrainment in horizontal flow in water-cooled nuclear reactor plays an important role in many transients such as IB-LOCA and LB-LOCA. A benchmark of system thermal-hydraulic (SYS-TH) codes capabilities to predicting the onset of droplet entrainment and entrainment rate was conducted within FONESYS. FONESYS is a network among code developers who share the common objective to strengthen current technology, to highlight the capabilities and the robustness as well as the limitations of current SYS-TH codes to predict the main phenomena during transient scenarios in nuclear reactors for safety issues. Mantilla performed 49 air-water tests with the 2-inch test section and 19 tests with the 6-inch test section at low pressure and temperature. Tests were selected aiming to support and complement an on-going activity on the scalability of codes’ closure laws, currently focusing on the horizontal stratification criteria and the onset of droplet entrainment and entrainment fraction criteria. Focus was put on the capability of ATHLET, CATHARE3, MARS-KS, RELAP5, RELAP5-3D, SPACE and TRACE in predicting the onset of droplet entrainment, the entrainment rate and pressure drops. Overall benchmark results show some spread in the results calculated by codes, highlighting the need for further research and development. Improving the capability in predicting dispersed flows might be beneficial for the analyses of different LOCA scenarios. The scalability of closure laws is discussed and possible ways for improving them are suggested.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
