
1) Nuclear weapon
Found on
https://www.crosswordclues.com/clue/radioflash

Radioflash is a term used (chiefly in sources from the United Kingdom) in early literature on the phenomena now known more widely as nuclear electromagnetic pulse, or EMP. The term originated in the early 1950s, primarily associated with the `click` typically heard on radio receivers when a nuclear bomb was detonated. It was later discovered tha.....
Found on
http://en.wikipedia.org/wiki/Radioflash
No exact match found.