The PERSEO facility test program conducted by ENEA at the SIET laboratories was aimed at verifying the operation of an innovative decay heat removal system for LWRs with in-pool heat-exchangers. The PERSEO project is an evolution of the Thermal Valve concept originally developed by the CEA where the triggering valve is installed liquid side, on a line connecting the bottoms of the heat-exchanger pool (HX-pool) and of the steam suppression pool (Overall pool). The two pools are also connected at the top by means of a steam duct ending with an injector. The latter accelerates the steam produced in the HX pool promoting a better homogenization of conditions in the overall pool. During normal operation the valve is closed, the HX pool is empty and the Overall pool is filled with water to the injector and exhaust level. In emergency condition the valve is opened and the HX pool is flooded with consequent heat transfer from the primary side to the pools. Among the different tests conducted on the PERSEO facility, Test n.9 aimed at demonstrating the behaviour of the system during long term accidental transients. The system is operated with total HX pool fill-up followed by reaching of boiling conditions in the Overall pool and accelerated water level decreasing. Test n.9 has been first analyzed by the CATHARE V2.5 code for validation purposes. Some assumptions on steam injector pressure drop, Overall pool height, boundary conditions at HX pool top during start-up and recirculation in the HX pool have been introduced to better reproduce the transient evolution. The comparison of the results obtained for a single volume nodalization and a 3-volume nodalization for the Overall pool shows that the main deviations between the calculation results and measurements are due to non-homogeneous void distribution in such a pool under boiling conditions. In order to further investigate the void distribution in the Overall pool, a CFD simulation of such a component has been carried out by the NEPTUNE CFD code. The CFD simulation is coupled to the CATHARE simulation by means of the boundary conditions, which are taken from the results of the system simulation. Comparison between predicted and experimental data for temperature at different location in the pool are presented.
Bassenghi, F. Donato, G. Bandini, M. Polidori, C. Lombardo, P. Meloni, et al. (2012). Analysis of the full scale PERSEO test for Decay Heat Removal in LWRs by coupling CATHARE V2.5 and NEPTUNE-CFD codes. BOLOGNA : University of Bologna.
Analysis of the full scale PERSEO test for Decay Heat Removal in LWRs by coupling CATHARE V2.5 and NEPTUNE-CFD codes
MANSERVISI, SANDRO
2012
Abstract
The PERSEO facility test program conducted by ENEA at the SIET laboratories was aimed at verifying the operation of an innovative decay heat removal system for LWRs with in-pool heat-exchangers. The PERSEO project is an evolution of the Thermal Valve concept originally developed by the CEA where the triggering valve is installed liquid side, on a line connecting the bottoms of the heat-exchanger pool (HX-pool) and of the steam suppression pool (Overall pool). The two pools are also connected at the top by means of a steam duct ending with an injector. The latter accelerates the steam produced in the HX pool promoting a better homogenization of conditions in the overall pool. During normal operation the valve is closed, the HX pool is empty and the Overall pool is filled with water to the injector and exhaust level. In emergency condition the valve is opened and the HX pool is flooded with consequent heat transfer from the primary side to the pools. Among the different tests conducted on the PERSEO facility, Test n.9 aimed at demonstrating the behaviour of the system during long term accidental transients. The system is operated with total HX pool fill-up followed by reaching of boiling conditions in the Overall pool and accelerated water level decreasing. Test n.9 has been first analyzed by the CATHARE V2.5 code for validation purposes. Some assumptions on steam injector pressure drop, Overall pool height, boundary conditions at HX pool top during start-up and recirculation in the HX pool have been introduced to better reproduce the transient evolution. The comparison of the results obtained for a single volume nodalization and a 3-volume nodalization for the Overall pool shows that the main deviations between the calculation results and measurements are due to non-homogeneous void distribution in such a pool under boiling conditions. In order to further investigate the void distribution in the Overall pool, a CFD simulation of such a component has been carried out by the NEPTUNE CFD code. The CFD simulation is coupled to the CATHARE simulation by means of the boundary conditions, which are taken from the results of the system simulation. Comparison between predicted and experimental data for temperature at different location in the pool are presented.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
