1N-VAR (核反应堆的)堆芯熔毁 If there is meltdown in a nuclear reactor, the fuel rods start melting because of a failure in the system, and radiation starts to escape. (核反应堆的)堆芯熔毁
Emergency cooling systems could fail and a reactor meltdown could occur.
紧急冷却系统有可能失灵，核反应堆有可能发生堆芯熔毁。
2N-UNCOUNT (公司、机构或系统的)崩溃，彻底失败 The meltdown of a company, organization, or system is its sudden and complete failure. (公司、机构或系统的)崩溃，彻底失败 [journalism]
Urgent talks are going on to prevent the market going into financial meltdown during the summer.