Writing prompts ripped from the headlines...
To ensure they got the right items, the specialists from Idaho brought radiation detectors and small samples of dangerous materials to calibrate them: specifically, a plastic-covered disk of plutonium, a material that can be used to fuel nuclear weapons, and another of cesium, a highly radioactive isotope that could potentially be used in a so-called "dirty" radioactive bomb.
Usage note: klaxon is a trademarked word that has become used generically, like Band-Aids, so you'll sometimes see it capitalized Klaxon.
My early-warning system set off an imaginary klaxon.
(The Dresden Files)
It was only on the third thought that she recognized them, as from the corridor outside, muffled by the door, an alarm klaxon began to hoot rhythmically.
Shards of Honor
Louis McMaster Bujold