CRIIRAD believes that the meteorological conditions (and air pollution actually in Europe) and (legal) authorizations of iodine-131 releases by the industry are the cause of this event which could have passed unnoticed
It is an unimportant event.
source : http://www.criirad.org/balises/CRIIRAD_170214%20_I131_Europe... (french)
Given the very short half-life of 131I being just 8 days and the daughter isotope 131Xe being stable this is a really weird policy.
There's no good reason to force nuclear installations to keep 131I in storage for, say, 80 days to dilute its activity down to 0.1%. Heck there's no good reason to release it it all.
The decay product is a noble gas, so you even get the separation chemistry for free. Iodine is a halogen so just let it react with some alkaline (pass it through some caustic solution) upon which is forms ionic bonds and turns into saline solution. As soon as the 131I decays into 131Xe it will recombine with an electron and gas out.
A mole of some chemical is a cardinal number and its a gross simplification but a "handful of stuff" has about ten to the twenty forth molecules or atoms. All to less than one sig fig. The exact number doesn't matter because enough half lives to dilute that much stuff to being statistically unlikely to contain less than 1 molecule is very large indeed. So at some point, where the radioactive activity is lower than say, a banana, or the ore it was dug out of, or a granite countertop, you just dump it. It takes a lot of half lives to take a banana down to zero radioactivity...
Probably the accident is somebody dumped the wrong bucket. You're supposed to dump bucket #32525 which has been aging for 100 half lives but accidentally bucket #64256 got dumped which was fresh. Or they reused buckets and markings (whoops there's two buckets labeled #15415)
Il a permis de détecter les retombées de Fukushima qui étaient environ 10000
fois supérieures à celles mesurées en janvier 2017 sur la France.
Unfortunately, the BfS charts are updated weekly... Do they publish latest readings in raw format somewhere? I couldn't find anything other than the delayed raster chart.
The difference was so small that I had just attributed it to normal fluctuations when I first saw it. Whatever caused this, so far it looks like it was a very small event.
I could probably provide a CSV-file with the raw data if anyone is interested. My Geiger counter stores a value every 5 minutes.
Could you pleae provide the CSV file?
The timestamps are in UTC+2. I keep the clock in the Geiger counter on daylight savings time. Too lazy to change it. :)
It stores the data in its internal memory which I then transfer via its USB port to my computer once a week.
The implication is that someone, somewhere had a nuclear accident and did not report it.
Hydrogen cooled turbogenerators are a thing, although I don't know if this plant used them, probably did. Nice and cool, high efficiency. The press release claims an alternator cooling fan overheated or whatever and that caused symptoms that sound like a hydrogen cooled turbogenerator having a nice leak and subsequent fire. Doesn't mention a steam leak. So that's like one more heat exchanger away from the fun stuff.
Explosions and fires and fire fighting can cause disruption and raise dust in theory, but the isotope detected has a very short half life so this wasn't a leak from a decade ago getting washed into the environment by a fire hose.
Its not seeming very likely.
Short half life, a nuclear event of some sort happened recently and nothing has been reported. I-131 is an isotope of Iodine and the source could be natural gas related, medical diagnostic OR a product of uranium and plutonium used in nuclear fission. 
Which countries have access to plutonium?
"only particulate iodine was reported."
What is the source of the particles?
"first found during week 2 of January 2017 in northern Norway."
What countries have access to plutonium that are active near Norway?
"Ces niveaux sont sans aucune conséquence sanitaire"
I suppose the interest is in understanding the source of it.
Why the month delay?
Could be Iodine being generated directly in place from other compounds or being seeded by suspended dust in clouds?
Could be this "Ukranian war" related?
It's good we are considering all options... :)
News in Finland's national broadcasting:
You could expect to have 25% still at 16 days (I said expect because this is a game of probabilities still).
Maybe we do not have sensors in the right places that could detect them.
I'll suggest to place some sensors in regular airlines and see what happens for example.
I am also really disappointed this wasn't anywhere in the news, at least people could have taken some iodine. I understand the level is low but there is still non-zero probability of somebody going ill from it.
Edit: I know this is harsh, but the OP should realize their post is somewhere on the anti-vaxxer-Facebook-post-scale. It's somewhere around a millipost, but it registers on the scale.
What should the news flash say? "Run from the nearest banana, person, airplane, or mountain."
I'm really disappointed at your disappointment despite an absolute lack of critical thought on your part. What fraction of a banana would you have to eat in order to have the same effect? How many nights would you need to sleep next to someone instead of alone to get the same dose? How many minutes at 30,000 feet does that correspond to?
Back-of-the envelope calculations: the half life is about 8 days, remembering your infinite series from high school, 1/2 + 1/4 + 1/8 ... = 1. So, the total dose over an infinite time frame is the same as 2 half lives at the initial level, so 16 days = 1,382,400 at 1.5e-6 Bq/m^3 works out to about 2 decays per cubic meter over an infinite time frame.
Even assuming you absorbed any decay from 10 cubic meters of air around you, I'm too lazy to look up the difference in number of Joules between Iodine and Potassium decay and work out what fraction of a banana you'd have to eat to get the same dose, or how many days of sleeping next to someone that works out to, but even assuming at steady state you absorb every radioactive decay from 10 m^3 of air (gigantic over-estimate), this is an absolutely tiny dose.
The danger of someone panicking and accidentally overdosing on iodine, or suffering a heart attack/stroke from the increased stress following such a news announcement is almost certainly higher than the risk of someone getting cancer from this.
I live in Hong Kong, where a fair number of people in finance moved from Tokyo following the Fukushima disaster out of radiation concerns. The natural background radiation levels in Hong Kong are higher in Hong Kong by more than the additional radiation in Tokyo due to Fukushima.
You've done literally over a hundred things in the past 24 hours that pose much more danger to you than 1.5 uBq / m^3 of iodine decay.
Anyway, why is it so bad to be concerned about health impact of even negligible radioactive release (are you sure newborns/sick do have the same threshold?) as an ordinary citizen, given the massive dishonesty of governments in the past in cases like Chernobyl or Fukushima? Why can't we just read in the newspapers within 2-3 days "we detected a minuscule amount of radiation, probably related to bad weather" or something, rather than keep a lid on it? Don't we deserve better? Or do we have to be handled like kindergarteners with somebody else deciding what is good for us to know?
And please stop with the banana examples, it's getting tiring. You 100% know there are various radioactive elements emitting different types of radiation, some way more dangerous than the others. Iodine by itself is just a first indicator but it's not the only element that gets released; some of the others are way more dangerous and we deserve to know. Not to mention there is a very different outcome if you just get some element on your skin or if it gets incorporated (cumulatively!) into your bones, organs or gets stuck in your lungs.
The news story should say "slightly elevated background radiation levels detected across Europe" and have an spokesman from the nuclear industry and a doctor quoted saying it's about as harmful as walking past a banana.
The fact we can't trust the media to report on something without inciting chaos is pretty awful.
Your position appears to be: we can't let the press report on interesting environmental anomalies because it could cause a panic. Meh.
My position is that it's detrimental to society to pressure the media into prominently covering non-issues that sound scary on the surface, without first taking the tiniest amount of effort to attempt to asses the level of danger. Such people should expect to be called out.
People are generally over-concerned about scary-sounding things of little to no danger, and vastly vastly under-concerned about mundane lifestyle issues that statistically pose the greatest threat to their health and lives. Those who openly criticize the media for lack of urgency in coverage without first checking if there's any actual danger of note should be made aware that they're contributing to the problem.
"Has There Been a Nuclear Incident in the Arctic?" ~ https://news.ycombinator.com/item?id=13683110
Poland is struggling right now because of huge smog. This makes me believe in this part of an article, which says that higher iodine detection might be caused by accumulation in smog.
If I had to place a bet, then I'd put it on some low to medium accident at a nuclear power station in Russia that led to an emergency release of contaminated steam.
I wondered so as well, but the second-highest was from Spain, and I struggle to form a consistent picture from that.
But due to the fact that they have not done so I assume it's harder than it looks.
When was the shield moved over Chernobyl?
How about a shield UNDER Chernobyl?
They started digging a tunnel in May 1986  (7 days after the accident), with a void below the reactor. They planned to fit a heat-exchanger into the void. It's not clear whether it was ever installed, but the consensus is that if it was installed, it was never used, and the core didn't reach the void .