THE Japanese owner of the stricken Fukushima nuclear plant falsified safety data and "dishonestly" tried to cover up problems there.



Tokyo Electric Power Co injected air into the containment vessel of Fukushima reactor No 1 to artificially "lower the leak rate". When caught, the company expressed its "sincere apologies for conducting dishonest practices".



The misconduct came to light in 2002 after whistleblowers working for General Electric, which designed the reactor, complained to the Japanese government. Another GE employee later confessed that he had falsified records of inspections of reactor No1 in 1989 - at the request of TEPCO officials. He also admitted to falsifying other inspection reports, also on request of the client. After that incident TEPCO was forced to shut down 17 reactors, albeit temporarily.



Dale Bridenbaugh, a GE employee who was not the whistleblower, resigned 35 years ago after becoming convinced that the design of the Mark 1 reactor used at Fukushima was seriously flawed. Five of the six reactors were built to that design.



Mr Bridenbaugh told ABC News: "The problems we identified in 1975 were that, in doing the design of the containment, they did not take into account the dynamic loads that could be experienced with a loss of coolant."



In a document entitled Lessons Learned from the TEPCO Nuclear Power Scandal, released by the company and seen by The Times, TEPCO blamed its "misconduct" in 2002 on its "engineers' overconfidence of their nuclear knowledge". Their "conservative mentality" had led them to fail to report problems, the company said, resulting in an "inadequate safety culture".



In 2007, TEPCO ran into trouble again after misinforming government officials about breakdowns at its Kashiwazaki-Kariwa plant, which had been damaged after a magnitude 6.8 quake. In a cable released by WikiLeaks, a US official said: "TEPCO issued a corrected statement on July 18 in which it admitted it miscalculated the amount of radiation leakage."



WikiLeaks cables also reveal that Japan was warned in 2009 that its power plants could not withstand powerful earthquakes.



The US was highly critical of Japan's senior safety director at the International Atomic Energy Association "particularly with respect to confronting Japan's own safety practices", according to confidential documents obtained by WikiLeaks. In July 2009, in a cable to Hillary Clinton, the Secretary of State, the US mission at the IAEA said Tomihiro Taniguchi, the deputy director of the IAEA department of nuclear safety and security, was a "weak manager" and in a cable sent later that year said that the department had suffered because of his "weak management and leadership skills".