基于ACENA程序的凤凰堆自然循环试验数值模拟

Numerical Simulation of the Natural Circulation Test of PHENIX Reactor by ACENA

自然循环余热排出是池式钠冷快堆重要的非能动安全特征,但同时也给钠冷快堆的设计与安全分析带来了新的问题和挑战。在全厂断电事故下,钠冷快堆能否建立起自然循环,自然循环能否带走堆芯的衰变热,是反应堆安全分析的重要内容。为验证液态金属堆事故分析程序ACENA在钠冷快堆自然循环余热排出的模拟计算的可靠性,对法国原子能委员会(CEA)在池式钠冷快堆凤凰堆寿期末开展的自然循环试验开展建模分析。模型中的钠池采用二维有限差分方法来考虑热分层对自然循环的影响。验证结果表明,ACENA能够准确分析钠冷快堆由强迫循环转变为自然循环的过程并对关键参数进行准确的预测,能够计算钠池内的热分层现象,具备钠冷快堆自然循环余热排出的计算能力。

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.