The most unusual event I encountered with neutron activation occurred a few days after April 26th 1986. Bernhard Spettel and I were doing some γ-counting on Ge(Li) crystals when we noticed unusual lines in the spectrum, which we quickly identified as arising from the decay of 131I with a half life of 12.36 h. We had no explanation and thought of some kind of unknown contamination of the sample. We opened the lead shield of the detector expecting a lower signal to background ratio. But instead the line grew faster. Then the first rumours of a reactor accident...
Research Article|April 01, 2018
Geochemical Perspectives (2018) 7 (1): 68.