meltdown vs smelting

meltdown

noun
  • Severe overheating of the core of a nuclear reactor resulting in the core melting and potentially in radiation escaping. 

  • An autistic response to stress or sensory overload, in which the person is overwhelmed by intense, seemingly disproportionate emotions, behaving erratically and becoming unable to mask. 

  • A tantrum or emotional outburst. 

  • A situation being likened to a nuclear meltdown; a crisis. 

  • Computer engineers were at a loss last night to explain why the Government had been hit by arguably the worst electronic meltdown in the history of Whitehall. https://web.archive.org/web/20041209011615/http://news.independent.co.uk/uk/politics/story.jsp?story=587262 

smelting

noun
  • The process of melting or fusion, especially to extract a metal from its ore. 

How often have the words meltdown and smelting occurred in a corpus of books? (source: Google Ngram Viewer )