Some 100 drums with low-level nuclear waste were discovered to have fallen over during the tremors, and some of their lids were found open during post-quake inspections of the plant, which was conducted after a two hour fire in the transformer adjacent to the plant’s number 3 reactor was extinguished, Japanese officials said.

It was not immediately clear Tuesday if any of the waste has leaked, as investigations of the tipped barrels was still underway, said the officials.

They also finally confirmed that small amounts of radioactive materials – cobalt 60, iodine and chromium 51 – had leaked into the atmosphere.

Water containing some 60,000 Becquerels of radioactive material is already known to have leaked from the plant’s reactor number 6 into the sea, but officials say it will not harm the environment. The Japanese NGO, the Citizens Nuclear Information Centre (CNIC), confirmed this to be the case if the figures on the leak reported by the nuclear power plant’s operator, the Tokyo Electric Company, are correct – and there is ample reason to suspect they are not.

First leak’s size only confirmed on Tuesday
The CNIC said in a statement to Bellona Web that Tokyo Electric had been far too sluggish in reporting the leakage from the world’s largest nuclear power plant, which has a total output of 8,212 megawatts, dwarfing it’s nearest competition in the US state of Arizona.

The company waited six hours to report that any leakage had occurred at, all and even then, it at first said no leakage had occurred, and then gave disputing accounts of how much water had in fact leaked. One Tokyo Electric official was quoted by the Associated Press as saying the plant leaked 1,190 litres of water, while another official told both Reuters and Bellona Web that only 1.5 litres had sloshed into the sea.

Officials with Tokyo Electric – who have in recent years been accused of covering up several serious nuclear power mishaps – revised their statement to Bellona Web on Tuesday, saying they had “only just discovered” that 1,200 litres of water had leaked.

The varying figures reported and both Tokyo Electric and the plant’s foot-dragging publication of details drew a harsh response from the Japanese government.

"I believe that nuclear power plants can only be operated with the trust of the people," Prime Minister Shinzo Abe told reporters.

"For this, if something happens they need to report on it thoroughly and quickly. We need to get them to strictly reflect on this incident," said Abe.

"They raised the alert too late. I have sent stern instructions that such alerts must be raised seriously and swiftly."

Tokyo Electric’s assertion that there was little to no damage to the environment is therefore suspect, especially in light of its cover up of “criticality incidents” – accidental self-sustaining nuclear chain reactions that could have led to nuclear explosions.

"We’re currently investigating the situation and plan to deal with it as smoothly as possible," the Associated Press news agency quoted him as saying.

Trust in nuclear industry hard to come by in light of scandal-tarred past
There have long been concerns about the safety of Japan’s nuclear power plants, which many fear are vulnerable in earthquakes – though nuclear energy accounts for a third of Japan’s energy production. Fears were not allayed by Tokyo Electric’s handling of yesterday’s incident. A previous scandal five years ago over fudged safety inspections has eroded public trust in the industry ever since.

"Japan is particularly prone to earthquakes, so I think it’s a major problem," he added. “Japan is one of the world’s most seismically active countries, and a tremor occurs at least every five minutes.”

"Japan is particularly prone to earthquakes, so I think it’s a major problem," he added. “Japan is one of the world’s most seismically active countries, and a tremor occurs at least every five minutes.”

The Japanese government requires that nuclear power plants be built to withstand quakes of a 6.5 magnitude, weaker than Monday’s jolt.

US nuclear regulators, who oversee 104 civilian reactors in the United States – compared with the 55 in Japan – said on Monday they were ready to send technical experts to Japan if help was required, news agencies reported.

One of the Japan’s worst nuclear accidents took place in September 1999, when workers at a nuclear facility in Tokaimura, northeast of Tokyo, set off an uncontrolled chain reaction by using buckets to mix nuclear fuel. Two workers were killed.

In 2004, four workers at a nuclear power plant were killed by a leak of high-pressure steam from a pipe.

There are currently 13 nuclear generators under construction in Japan and the government’s policy is to continue to rely on nuclear power for 30 to 40 percent of the country’s electricity requirements.