The QUENCH experimental programme at Karlsruhe under severe accident conditions, but while the geometry is still Institute of Technology investigates heat-up and reflooding of a core mainly rod-like. The recent QUENCH...The QUENCH experimental programme at Karlsruhe under severe accident conditions, but while the geometry is still Institute of Technology investigates heat-up and reflooding of a core mainly rod-like. The recent QUENCH-ACM series of experiments, comprising QUENCH-12 （El 10 cladding alloy）, -14 （M5 alloy） and -15 （Zirlo^TM alloy）, together with QUENCH-06 （reference case, Zircaloy-4 alloy） addressed the effect of alternative cladding materials on oxidation and quenching under similar conditions. Superficial inspection of the experimental results reveals only minor differences in the thermal and oxidation response, except for the much larger hydrogen release during reflood in QUENCH-12. Post-test calculations were performed using a version of SCDAP/RELAP5/MOD3.2, modified to represent the QUENCH facility and to invoke alternative oxidation correlations. The calculations agreed rather well with experiments QUENCH-06, -14 and -15, but the significant hydrogen release during reflood in QUENCH-12 was not captured. Closer examination of the experimental results reveals further differences between QUENCH-12 which may be linked to breakaway oxidation of the E110 cladding. The analyses support the heuristic observation that there was no major difference between the influence of Zircaloy-4, M5 or ZirloTM, but the E-110 exhibited a contrasting behaviour with a consequent impact on the reflooding.展开更多
The occurrence of a PTS （pressurized thermal shock） in a reactor vessel is an important phenomenon for assessing nuclear reactor safety. New experiment was conducted at HZDR （Helmholtz-Zentrum Dresden-Rossendorf）,...The occurrence of a PTS （pressurized thermal shock） in a reactor vessel is an important phenomenon for assessing nuclear reactor safety. New experiment was conducted at HZDR （Helmholtz-Zentrum Dresden-Rossendorf）, focused on thermal mixing processes in the cold leg and the downcomer of two-phase PTS case. Present work reports CFD （computational fluid dynamics） ana｜ysis of steady-state air-water case. CFD analysis was conducted with two turbulence-modeling approaches, RANS （Reynolds Averaged Navier-stokes） and LES （large eddy simulations）. Multiphase situation was modeled with VOF （volume of fluid） approach. Simulations were performed using the FLUENT 12 package. Comparison of computed temperatures results and measurements along the thermo-couple lines revealed results depend on the turbulence model used.展开更多
文摘The QUENCH experimental programme at Karlsruhe under severe accident conditions, but while the geometry is still Institute of Technology investigates heat-up and reflooding of a core mainly rod-like. The recent QUENCH-ACM series of experiments, comprising QUENCH-12 （El 10 cladding alloy）, -14 （M5 alloy） and -15 （Zirlo^TM alloy）, together with QUENCH-06 （reference case, Zircaloy-4 alloy） addressed the effect of alternative cladding materials on oxidation and quenching under similar conditions. Superficial inspection of the experimental results reveals only minor differences in the thermal and oxidation response, except for the much larger hydrogen release during reflood in QUENCH-12. Post-test calculations were performed using a version of SCDAP/RELAP5/MOD3.2, modified to represent the QUENCH facility and to invoke alternative oxidation correlations. The calculations agreed rather well with experiments QUENCH-06, -14 and -15, but the significant hydrogen release during reflood in QUENCH-12 was not captured. Closer examination of the experimental results reveals further differences between QUENCH-12 which may be linked to breakaway oxidation of the E110 cladding. The analyses support the heuristic observation that there was no major difference between the influence of Zircaloy-4, M5 or ZirloTM, but the E-110 exhibited a contrasting behaviour with a consequent impact on the reflooding.
文摘The occurrence of a PTS （pressurized thermal shock） in a reactor vessel is an important phenomenon for assessing nuclear reactor safety. New experiment was conducted at HZDR （Helmholtz-Zentrum Dresden-Rossendorf）, focused on thermal mixing processes in the cold leg and the downcomer of two-phase PTS case. Present work reports CFD （computational fluid dynamics） ana｜ysis of steady-state air-water case. CFD analysis was conducted with two turbulence-modeling approaches, RANS （Reynolds Averaged Navier-stokes） and LES （large eddy simulations）. Multiphase situation was modeled with VOF （volume of fluid） approach. Simulations were performed using the FLUENT 12 package. Comparison of computed temperatures results and measurements along the thermo-couple lines revealed results depend on the turbulence model used.
