@ai6yr
Wow, by far the most coherent and complete write-up. Also some pretty useful info I haven't seen elsewhere:

'Soon after, Jakarta port operators about 60 kilometers (37 miles) away missed an opportunity when the offending containers were loaded onto ships. At least two containers were flagged by radiation detectors, according to a person familiar with the matter. Whether those readings were missed or ignored isn’t clear.

Elsewhere, however, the event was detected, if not immediately noted. Radionuclide monitoring stations more than a thousand kilometers away in Malaysia and in the remote Australian territory the Cocos Islands - part of a global network of sensors deployed by the Vienna-based Comprehensive Nuclear-Test-Ban Treaty Organisation - picked up traces of radiation, Indonesian officials would later be informed. A unit of the US Department of Energy would say in a preliminary assessment seen by Bloomberg News that detections by two different stations at that distance suggests “a significant airborne release” of Cesium-137.'

I'm curious to know what "significant" means in this context.