The Helsinki cesium-137 spike.

An abnormally high spike in cesium-137 was detected in Helsinki, Finland on March 3 and 4. It measured 4,000 microbecquerels per cubic meter of air. It was the highest reading since immediately after the Chernobyl catastrophe in 1986.

Officials at STUK, Finland’s radiation protection agency, explained the spike by somebody tracking cesium on their shoes in the parking garage:

In a bizarre twist, nuclear safety regulator STUK said in a statement that caesium-137, a radioactive isotope of caesium, had been tracked to the basement and garage of the very same building where it has its offices.

“In the same building there is also a company that deals with low-level radioactive waste,” STUK said.

Yes, this organization dedicated to radiation safety shares their building with dealers in low-level radioactive waste. Yes, this is bizarre, but perhaps not too surprising, given the track record of radiation protection organizations in covering up radiation disasters.

And you gotta wonder where their detector is, how the particles made it there, etc.

Leaving this strangeness behind, maybe we can explain this by an authentic emission of radioactivity from somewhere. I used HYSPLIT to trace back any wind-driven plume. STUK was not too specific as to the timing, though… they said it was “between March 3 and 4”. So I used midnight local time on the night of the 3rd as the terminus.

The path brings up two possibilities:

Theory 1. The Leningrad nuclear plant is nearby, and the plume path is very close to this location. Last December, there was a radioactive release from this plant. The plume went up through Finland, and the spike was visible on many monitors. Maybe something happened at this plant again.

Theory 2. The plume path intersects the Arctic Ocean at the city of Severomorsk. “The town is the main administrative base of the Russian Northern Fleet. Severomorsk has the largest dry dock on the Kola Peninsula.” (Wikipedia) This would suggest an accident with a Russian naval submarine.

Another possibility is Fukushima, but this spike is higher than any in 2011, and this would seem unlikely. Though the Fuku plant has been actively emitting steam recently.

There is additional discussion at the Allegedly Apparent Blog.