Yeah, no shit. But, come on, don't play dumb. By measurable, I obviously meant "above normal background". Something that shouldn't have been possible if, as described in the xkcd post, the water should have had less radioactivity than normal background. Combined with the fact that the post was literally about a different kind of pool than the one involved in the accident, it was reasonable to question whether the post was actually relevant.

I agree this was not a serious incident, and I never really though it was. (I'm extremely pro-nuclear, for the record.) But at the time I posted, the comment section was about 8 people posting the xkcd link at once (with no additional commentary), and few others reading it and saying "oh, no problem then", with literally nobody pointing out the discrepancies, or explaining exactly what a "reactor cavity" means in this context.

Background is probably a bit lower depending on where you're at. My counter went through airport security luggage scans 'cause they wouldn't let me wear it through the metal detector. It beeps for a few seconds and then comes out about a days' dose of natural radiation higher. The count was higher than 300 CPM, but obviously only shortly. That poor bloke might stay at 300 (if ingested and he can't scrub it off) for a while but it's still not very discouraging long-term. Pilots have about that at cruising altitude.