Some of the workers at Fukushima Dai-ichi plant discovered an oil spill in the ocean near reactors five and six, which were in shutdown when the earthquake and subsequent tsunami struck on March 11, 2011, according to Tokyo Electric Power Co. The spill was contained by an oil fence, TEPCO spokesman Taichi Okazaki said.
The explosion that the workers heard at reactor number four was more than likely from a gas tank and did not cause any additional radiation leaks, Okazaki said. The causes of the spill and explosion are currently under investigation.
The main problems that exist at Fukushima Dai-ichi Nuclear power plant involve reactors one, two and three, where the fuel cores have melted, due to problems related to the earthquake and tsunami which struck the plant. Scientists and government officials say the reactors are short of a full meltdown, in which the fuel breaks through the bottom of the containment building.
Workers have been fighting to get the reactors under control after the tsunami destroyed backup power generators, halting crucial cooling systems that managed the fuel rod temperatures.
In the immediate days after the tsunami, several explosions larger than Tuesday’s hit the plant and scattered highly radioactive debris and puffs of radioactivity particles into the atmosphere and nearby environment. The plant has also leaked tons of radioactive water, which officials are promising to clean up.
TEPCO has promised to bring the plant under control by January, but fears are growing that is being far too optimistic.