Yesterday’s link, which spent some time discussing the discovery of Francium, reminds me of a Francium story that I’ve briefly mentioned before in a story of how we failed to trap Francium, but got the attention of someone else.

And, as I had mentioned, we (well, someone at TRIUMF) got a call from a watchdog station that tries to detect nuclear fallout, wanting to double-check on things. They knew the signature they were reading wasn’t from a bomb, but they knew something was up and guessed our target material: Thorium. When you blast that with energetic protons, you get lots of heavy isotopes.

I ran across a paperfrom some folks at the monitoring facility

The United States and Canada have jointly established an experimental radio-aerosol monitoring station in Vancouver, British Columbia as part of the International Monitoring System for the Comprehensive Nuclear Test Ban Treaty. The purpose of this station is to monitor the atmosphere for the presence of anthropogenic radio-aerosols that could be indicative of nuclear explosion debris. The station has been engineered to achieve detection sensitivities that are approximately three orders of magnitude higher than conventional environmental and emergency preparedness monitors. Due to its ultra-sensitive measurement capability, the station has regularly detected micro quantities of radioisotope emissions from a nearby commercial production facility that would otherwise have gone unnoticed. The major isotope, 123I, was identified by spectroscopic analysis and correlated to the facility through source emission data.

TRIUMF would probably not be considered a commercial production facility. Although it’s possible they were making this radioisotope in conjunction with a commercial partner, I’m guessing that it was a medical radioisotope production facility. Same kind of sleuthing for the monitoring station, but a different culprit.