高温堆芯熔融物池瞬态反应机理研究

Study on transient reaction Mechanism of High-temperature Corium Pool of Core

摘要:

为模拟核电厂高温堆芯熔融物堆内滞留的瞬态现象,采用冷坩埚电磁感应加热熔炼50kg级ZrO₂-Fe-Zr体系的混合物,通过XRD、SEM、EDS等检测手段分析了凝固后的熔融物铸锭的氧化层、金属层和氧化结壳的物相和元素分布情况。结果表明：50kg级初始熔池形成过程中,高温熔融物由于重力作用和不相容性分离成金属层和氧化层的两层结构,在熔池顶部及周围形成氧化结壳。之后,由于二次加料形成顶部液态金属三层熔池,顶部金属熔池可穿过氧化物硬壳以液滴状逐渐沉降到熔池底部。

Abstract:

In order to simulate the transient phenomenon of retention in high temperature core melt of nuclear power plant, the mixture of 50kg ZrO2-Fe-Zr system was melted by electromagnetic induction in a cold crucible. The phase and element distribution of oxide layer, metal layer and oxide crust of solidified melt ingot were analyzed by means of XRD, SEM, EDS and so on. The results show that during the formation of the 50-kg-scale initial molten pool, the high temperature molten material is separated into a two-layer structure of metal layer and oxide layer due to gravity and incompatibility, and an oxidation crust is formed on and around the top of the molten pool; After that, due to the secondary feeding to form a three-layer molten pool with the top liquid metal, the top metal molten pool can gradually settle to the bottom of the molten pool through the oxide hard crust.