I noted a few weeks ago that the vent tower in the foreground of unit 2 had been oddly illuminated (for example, see my discussion here).
It was hard for me to tell whether the "steam" (presumably) coming up behind the vent tower originated in unit 2, the ground (possibly the underground ice-wall), or from unit 3, which is out of view.
Here is a recent screen shot from April 7, 2019 at 1:43 - Notice the diffuse steam coming up from areas around unit 1 (closest to camera) and the vent tower in the foreground of unit 2: