I didn’t know urea based fertilizer has a radiation signature.
If you remember from the tests, there was no radiation sig until the media reported “Hm, that’s strange, this nuke test has no radionucleotides,” upon which they were almost instantly released to the satisfaction of all (2006). 2009 there we none released, period. 2013’s I haven’t heard any reports of, but the fact that it happened in the EXACT same place as 2006, just with more intensity is strange if it was an actual nuke.