基于ACENA程序的凤凰堆自然循环试验数值模拟

Natural circulation decay heat removal is is an important passive safety feature of pool-type sodium-cooled fast reactor (SFR), but it also brings new problems and challenges to the design and safety analysis of SFR. Whether the natural cycle can be established and whether the natural cycle can take away the decay heat of the core is an important part of the reactor safety analysis under station black-out accident (SBO). In order to verify the reliability of the liquid metal accident analysis code ACENA in the simulation of natural cycle decay heat removal in SFR, the natural circulation test conducted by the French Alternative Energies and Atomic Energy Commission (CEA) at the end of the life of pool-type sodium-cooled fast reactor PHENIX was modeled and analyzed. The effect of thermal stratification on natural circulation was considered by two-dimensional finite difference method in sodium pool. The verification results show that ACENA can accurately analyze the process of forced circulation to natural circulation and accurately predict the key parameters. The code can also calculate the thermal stratification phenomenon in the sodium pool, and has the calculation capacity of natural circulation decay heat removal.