Right, you know it's somewhat of a beat-up when 'highly radioactive' and 'substance' are bound together. Whenever I see the word substance used instead of the m

Right, you know it's somewhat of a beat-up when 'highly radioactive' and 'substance' are bound together. Whenever I see the word substance used instead of the more appropriate element then one has to be wary. Incidentally, as I write, I can see an historic 100TH vacuum tube in a box on a shelf, it uses a thoriated tungsten filament: http://www.r-type.org/exhib/aaq0385.htm http://www.r-type.org/exhib/aaq0385.htm. I've no qualms about being near it but if it got broken then I'd take care to clean the mess up and dispose of it carefully, I'd even use an N90 mask whilst sweeping the bits up (but then I've always used masks in industrial/dusty environments—even before COVID).