My army unit had a dozen of these tritium-lit U.S. military wrist watches. They really were very nice. Tritium has a half-life of about 12 years. As I recall, the watches had a wear-out date after which we had to turn them in so they could give us new ones. We kept them locked up in a safe with the fancy knives, a couple of compasses, some kind of beryllium gizmo, and the pistol lanyards. Once a month the Property Book Officer (me) and a witness opened the safe and counted the watches and other stuff. Once a year for the big inspection a Major came down from headquarters and counted them. Because, you see, those watches are radioactive and expensive.
We could have, in theory, issued them to soldiers in the unit. But watches get lost, or they break, or they get stolen (or “stolen”) and turn up in a pawn shop in Phenix City leaking tritium. With these there would have been a pile of paperwork to fill out because of the radioactive material; and the soldier would have been billed an enormous sum for the watch.
If you haven’t been in the military, you might think we could just not have them; return the watches to the supplier and get the taxpayer some money back. No such thing was remotely possible. We had to possess them to pass the annual inspection. Well, I did my job. The inspections went smoothly when I was there, except once when an extra pistol lanyard appeared somehow. Fortunately, a resourceful Specialist made it disappear again. The watches were in the safe when I left.