I googled for "Jukka Laaksonen" arctic sea site:.fi to see if there would be some more details or the original Finnish text. The repetitive use of "stupid" seems a bit odd. The only hits were discussion threads referring to the AFP story. It seems like a common conspiracy theory that a russian nuke has been stolen and there's a coverup. Conspiracy theory since I think it's an obvious conclusion to draw yet going far overboard given what's currently known.

Jukka Laaksonen is the head of Finland's Radiation Safety Agency. There's also a well-known impersonator/comedian with the same name. It would be hilarious if AFP called the wrong guy ;)