Separate-effect experiment simulating steam direct-contact condensation on ECCS （emergency core cooling system） water in PWR （pressurized water reactor） cold legs during reflood phase of large-break LOCA （loss-of...Separate-effect experiment simulating steam direct-contact condensation on ECCS （emergency core cooling system） water in PWR （pressurized water reactor） cold legs during reflood phase of large-break LOCA （loss-of-coolant accident） was conducted in OECD/NEA ROSA Project using the LSTF （large scale test facility）. A new test section was furnished in the downstream of the LSTF break unit horizontally attached to the cold leg. Significant condensation of steam appeared in a short distance from the simulated ECCS injection point, and the steam temperature in the test section decreased immediately after the initiation of the ECCS water injection. Total steam condensation rate estimated from the difference between steam flow rates at the test section inlet and outlet was in proportion to the simulated ECCS water mass flux until the complete condensation of steam. Clear images of high-speed video camera were successfully obtained on droplet behaviors through the viewer of the test section, especially for annular mist flow.展开更多
The safety analysis code SCTRAN for SCWR(Super Critical Water Reactor) is modified to own the capability to assess the radiation heat transfer with developing a two-dimensional heat conduction solution scheme and inco...The safety analysis code SCTRAN for SCWR(Super Critical Water Reactor) is modified to own the capability to assess the radiation heat transfer with developing a two-dimensional heat conduction solution scheme and incorporating a radiation heat transfer model. The verification of the developed radiation heat transfer model is conducted through code-to-code comparison with CATHENA. The results show that the modified SCTRAN code is successful for that the maximum absolute error and relative error of the surface temperature between results of SCTRAN and CATHENA are 6.1°C and 0.9%, which are acceptable in temperature prediction. Then,with the modified SCTRAN code, the loss of coolant accident with a total loss of emergency core cooling system(LOCA/LOECC) of Canadian-SCWR is carried out to evaluate its "no-core-melt" concept. The following conclusions are achieved: 1) in the process of LOCA, the decay heat can be totally removed by the radiation heat transfer and the natural convection of the high-temperature coolant, even without an intervention of ECCS(Emergency Core Cooling System); 2) The peak cladding temperature of the fuel pins in the inner and outer rings of the high power group are 1236°C and 1177°C respectively, which are much lower than the melting point of the fuel sheath. It indicates that the Canadian-SCWR can achieve "no-core-melt" concept under LOCA/LOECC.展开更多
文摘Separate-effect experiment simulating steam direct-contact condensation on ECCS （emergency core cooling system） water in PWR （pressurized water reactor） cold legs during reflood phase of large-break LOCA （loss-of-coolant accident） was conducted in OECD/NEA ROSA Project using the LSTF （large scale test facility）. A new test section was furnished in the downstream of the LSTF break unit horizontally attached to the cold leg. Significant condensation of steam appeared in a short distance from the simulated ECCS injection point, and the steam temperature in the test section decreased immediately after the initiation of the ECCS water injection. Total steam condensation rate estimated from the difference between steam flow rates at the test section inlet and outlet was in proportion to the simulated ECCS water mass flux until the complete condensation of steam. Clear images of high-speed video camera were successfully obtained on droplet behaviors through the viewer of the test section, especially for annular mist flow.
基金Supported by the Doctoral Program of Higher Education of China(No.20120201110043)Atomic Energy of Canada Limited(AECL)
文摘The safety analysis code SCTRAN for SCWR(Super Critical Water Reactor) is modified to own the capability to assess the radiation heat transfer with developing a two-dimensional heat conduction solution scheme and incorporating a radiation heat transfer model. The verification of the developed radiation heat transfer model is conducted through code-to-code comparison with CATHENA. The results show that the modified SCTRAN code is successful for that the maximum absolute error and relative error of the surface temperature between results of SCTRAN and CATHENA are 6.1°C and 0.9%, which are acceptable in temperature prediction. Then,with the modified SCTRAN code, the loss of coolant accident with a total loss of emergency core cooling system(LOCA/LOECC) of Canadian-SCWR is carried out to evaluate its "no-core-melt" concept. The following conclusions are achieved: 1) in the process of LOCA, the decay heat can be totally removed by the radiation heat transfer and the natural convection of the high-temperature coolant, even without an intervention of ECCS(Emergency Core Cooling System); 2) The peak cladding temperature of the fuel pins in the inner and outer rings of the high power group are 1236°C and 1177°C respectively, which are much lower than the melting point of the fuel sheath. It indicates that the Canadian-SCWR can achieve "no-core-melt" concept under LOCA/LOECC.
