It strongly appears that nuclear criticalities are occurring at the Fukushima Daiichi site.
Most recently, the criticality events result in pink pixillation that seems to emanate from (as viewed via TBS cam) early Tue morning:
1. Unit 1: hard to tell which corner
2. Unit 2: the right hand corner
3. Units 3 and 4: left side of 4, near 3
4. Common spent fuel pool
See here for more screenshots: https://www.dropbox.com/s/o95wsoc1sf6k3ks/Feb%2018%202014%20B.pdf
LostWorld made this video of a previous event: https://www.dropbox.com/s/f4baftzj8xouqlu/2-14-14.mp4
What is occurring now is different from the fire and/or criticality that occurred over the summer of 2013: