This hopefully may be nothing but fog. But starting last evening the Fukushima webcam started whiting out. At 7 pm EST it was overcast with snow flurries and crane activity could be seen. At 9 PM the reactor buildings, tower, and cranes were obscured (although an instance of a bird flying between the buildings and the cameras was not). Right now the camera lens is totally obscured by what appears to be condensation.
Might be a steam release, might not.
Here's the webcam link, if you want to take a look.
Fukushima