The behavior of ITER-like W/Cu plasma facing components under complex conditions in current tokamaks is one of the main concerns for ITER. EAST has installed a full upper W divertor with the ITER-like W/Cu monoblocks as targets since 2014. A melting failure of CuCrZr cooling tube of W/Cu monoblocks has occurred during the plasma campaigns in 2019. Due to the loss of cooling water, the leading edge-induced thermal loading can lead to the melting of both W armor and CuCrZr cooling tube, which has been confirmed by thermal simulation and analysis. With movement and migration of the melted Cu through gaps, the structure and function of the CuCrZr cooling tube for W/Cu monoblocks was severely destroyed. As a result, those failed W/Cu monoblocks had to be replaced. Such case in EAST just simulates the extreme condition of accidental loss of coolant in future devices. The melting failure of CuCrZr cooling tube was caused by operation without coolant water at largely misaligned monoblocks, which is a key lesson referenced to other tokamaks which adopt or plan to apply such type of W/Cu monoblocks.

在目前的托卡马克中，复杂条件下类似ITER的W / Cu等离子体面对部件的行为是ITER的主要问题之一。自2014年以来，EAST已安装了一个完整的上部W分流器，以类似ITER的W / Cu单体作为目标。在2019年的等离子运动期间，W / Cu单体的CuCrZr冷却管发生了熔化故障。由于冷却水的流失，由前沿引起的热负荷会导致W装甲和CuCrZr冷却管熔化，这已通过热仿真和分析得到了证实。随着熔化的铜通过间隙的移动和迁移，用于W / Cu整体块的CuCrZr冷却管的结构和功能被严重破坏。结果，必须更换那些失效的W / Cu单体。EAST中的这种情况仅模拟了未来设备中冷却剂意外损失的极端情况。CuCrZr冷却管的熔化故障是由于在未完全对准的情况下在没有冷却水的情况下运行而引起的，这是参考其他采用或计划应用这种W / Cu单体的托卡马克的重要课程。