Haven’t been able to get this from more than one source, but here’s all I know at the moment:
Fukushima nuclear plant reports new explosion, oil spill
Published: May 31, 2011
A small explosion occurred at the Fukushima Daiichi nuclear power plant in Japan on May 31 and workers discovered an oil spill, according to the Guardian newspaper. Both incidents reportedly caused limited damage and no further radiation leaks, according to Tokyo Electric Power Co.
Workers heard an explosion at Unit 4 on May 31. It likely came from a gas tank and did not cause any radiation leaks. The cause of the explosion is under investigation.
Workers found the oil spill in the sea near reactors 5 and 6, which were shut down during the earthquake and tsunami on March 11. An oil fence contained the spill, a TEPCO spokesperson was quoted as saying.
More as it becomes available….