China Experimental Fast Reactor Sodium Pool Of Three-dimensional Thermal Hydraulic Analysis

China Experimental Fast Reactor(CEFR) is under construction. There are many equipments important to safety in-vessel of CEFR, such as intermediate heat exchanger, decay heat exchanger, primary coolant pump, and core support structure. In order to get stress analysis and assessment to these equipments ,it is necessary to understand clearly the thermal-hydraulical behavor in-vessel of CEFR. At the same time ,CEFR is the first pool-type LMFBR(Liquid Metal Fast Breeder Reactor)using dacay heat removel system to remove core decay heat. Because it is very complicated in CEFR either in normal condition or accident condition, numerical analysis is important in these cases that the out-of-pile test have not been performed .Upon the investigation on the domestic and foreign status of this issuse,and according to the situation of CEFR, the detailed numerical analysis is performed using CFD software.The major researches are outlined as the following four aspects.1. Different from the previous procedure in which the hot plenum and cold plenum are calculated separately ,the whole model including hot and cold plenum has been setted up in the present paper. It improves the calculation precision greatly.2. The influence of the radial shielding to simulation has been considered using porous media method, at the same time the validity of the method has been verifyed.The results of calculation show that it improves the economics of the numerical analysis and simplifies the difficulity of setting up the model;3. A complicated model has been setted up to simulate the sodium flow in hot and cold plenum under normal condition and reactor scram of CEFR, using fine grid to simulate the reactor internals and important equipments . This slove the problem that the simulation grids are very coarse in the precedeable work , and the accuracy and reliability of the simulation are improved.4. A numerical model has been established which is suitable to CEFR steady state and transient simulation. In these cases, a lot of calculation data have been accumulated during the analysis ,including pro-process macro file named grid.mac ,process control macro file named cal_control.mac, and post-process fortran file named posdat.f. These data and files are very useful to thermal-hydraulical analysis of CEFR and prototype pool-type LMFBR thermal design in the future.Through the above analyses, the following results can be concluded:1).The porous media method is effective .It will improve the economics of numerical analysis of engineering issues.2).It has a great temperature gradient along the height in hot and cold plenums of CEFR in steady state. The buoyancy force cannot be ignored because the flow velocity is low in the whole flow regions.3).The flow velocity and temperature change rapidly in hot plenum under the transient condition such as in the case of reactor scram condition .Thermal stratification phenomena will be observed nearby the inlet of intermediate heat exchanger.