严重事故下原型熔融物实验研究

Experimental Study on Prototype Melt under Severe Accident

为研究严重事故条件下压力容器下封头熔融池分层行为,需将原型熔融物熔化为液态开展实验。本研究采用CESEF实验装置,使用电磁冷坩埚技术熔化原型熔融物,最高装料量为5000 g,最高温度为3000℃。配套的高频电源功率为400 kW,频率为100 kHz。针对华龙一号堆芯熔融物组分开展实验研究,研究发现熔融池出现了明显的分层,一层为金属层,一层为氧化层。通过对金属层和氧化层不同位置取样分析,发现金属层中主要为不锈钢成分、部分U和Zr,氧化层主要为亚氧化状态的U、Zr和O,其他含量很少。

In order to study the stratification morphology of the molten pool of the lower head of the pressure vessel under severe accident conditions,it is necessary to melt the prototype melt into liquid for experiments.In this study,CESEF experimental device is used,and the prototype melt is melted with the electromagnetic cold crucible technology.The maximum charge capacity is 5000 g,and the maximum temperature is 3000°C.The supporting high-frequency power supply is of 400 kW and a frequency of 100 kHz.An experimental study is carried out on the composition of Hualong One(HPR 1000)core melt,and it is found that the molten pool is divided into two layers:the metal layer and the oxide layer.By sampling different positions of the metal layer and oxide layer,it is found that the metal layer is mainly composed of stainless steel with some U and Zr,and the oxide layer is mainly composed of U,Zr and O in suboxide state,with few other contents.