Japan media reports on new daytime video showing steam rising from Reactors No. 2 and 3 — Asahi: “Under the steam are the reactors” (VIDEOS

Fukushima I Nuke Plant: Steam Rising from Reactors 2 and 3, EX-SKF, September 24, 2011:

The latest videos of Reactors 2 and 3 at Fukushima I Nuclear Power Plant show steam rising from the locations where the reactors are located. [...]

According to Asahi Shinbun (9/24/2011), TEPCO thinks:

“Under the steam are the reactors. It could be either the steam is escaping from the reactor, or the rainwater is evaporating on the lid of the reactor which is hot.”
Looking at the videos, they do not look like rainwater being evaporated, as the steam comes out unevenly and sporadically. If it’s rainwater I would imagine a steady rise of steam.
Reactor No. 3 taken on August 24 -- Steam at 1:10 in

[link to ex-skf.blogspot.com]