Can someone describe the significance/insignificance/context of this?
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. [0]
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?
http://www.cnn.com/interactive/2013/03/world/nuclear-weapon-...
"Ces niveaux sont sans aucune conséquence sanitaire"
I suppose the interest is in understanding the source of it.