钠与混凝土反应的计算机模拟

Computer Simulation for Sodium-Concrete Reactions

针对钠冷快堆可能发生的钠-混凝土反应,开发了一套用于模拟反应全过程,能求解发生钠-混凝土反应之后反应区温度、钠池温度、渗透深度、渗透率、氢气释放速率以及释放的化学反应能等变量的程序。笔者将成分复杂的混凝土模拟为硅土和水的混合物,并在连续性方程中引入氢氧化钠份额,将难以求解的净蒸汽流量与边界层厚度的乘积转化为渗透速率与边界层厚度的乘积；将计算结果与试验值进行了比较。结果证明,程序计算结果可信,采用模型和假设合理。

In the liquid metal cooled fast breeder reactors （LMFBRs）, direct contacts between sodium and concrete is unavoidable. Due to sodium＇s high chemical reactivity, sodium would react with concrete violently Lots of hydrogen gas and heat would be released then. This would harm the integrality of the containment. This paper developed a program to simulate sodium-concrete reactions across-the-board. It could give the reaction zone temperature, pool temperature, penetration depth, penetration rate, hydrogen flux and reaction heat and so on. Concrete was considered to be composed of silica and water only in this paper. The variable, the quotient of sodium hydroxide, was introduced in the continuity equation to simulate the chemical reactions more realistically. The product of the net gas flux and boundary depth was ably transformed to that of penetration rate and boundary depth. The complex chemical kinetics equations was simplified under some hypothesises. All the technique applied above simplified the computer simulation consumedly. In other words, they made the computer simulation feasible. Theoretics models that applied in the program and the calculation procedure were expatiated in detail. Good agreements of an overall transient behavior were obtained in a series of sodium-concrete reaction experiment analysis. The comparison between the analytical and experimental results showed the program presented in this paper was creditable and reasonable for simulating the sodium-concrete reactions. This program could be used for nuclear safety judgement.