U.S. Called Former Japan Nuclear Safety Official a 'Disappointment': WikiLeaks Former IAEA official advised stricter safety to "avoid another Chernobyl."

March 15, 2011  -- Two years before a powerful earthquake rocked Japan and threatened catastrophe for its nuclear facilities, U.S. officials slammed the senior Japanese safety director of the International Atomic Energy Agency as "a disappointment" in part due to Japan's nuclear safety practices, according to a leaked U.S. State Department document.

"[Tomihiro] Taniguchi has been a weak manager and advocate, particularly with respect to confronting Japan's own safety practices, and he is a particular disappointment to the United States for his unloved-step-child treatment of the Office of Nuclear Security," said the document, posted on the website for British newspaper The Guardian. "This position requires a good manager and leader who is technically qualified in both safety and security."

Taniguchi was the executive director of Japan's Nuclear Power Engineering Corporation, a company that specifically dealt with nuclear plant security in the aftermath of earthquakes, prior to becoming the Deputy Director General for the IAEA's Department of Nuclear Safety and Security in 2001. Taniguchi stepped down after another Japanese official, Yukiya Amano, assumed control of the IAEA as Director General in September 2009.

Before he left, however, Taniguchi told a meeting of nuclear officials in 2008 that the international community should focus more on nuclear power safety and security, according to a separate leaked cable posted on the website WikiLeaks.

"We should avoid another Chernobyl or nuclear 9/11," Taniguchi said according to the document, referring to the infamous 1986 nuclear disaster in the Ukraine.

After Japan suffered one of its largest earthquakes in history March 11, one of the country's nuclear plants was so badly damaged it prompted fears of a disaster and invited comparisons to the Chernobyl incident.

Amano, now the sole representative from Japan on the senior IAEA management team, is scheduled to speak in April about the safety improvements made since that incident at an international conference called "Chernobyl, 25 Years On: Safety for the Future."

CLICK HERE to read ABC News' full coverage on the Disaster in the Pacific.

Japan's 3-Step Plan for Nuclear Safety

In the same 2008 meeting in which Taniguchi pushed for more international safeguards when it comes to nuclear power, other IAEA officials "saw promise in the Japanese 3S's (Safety, Security, Safeguards) proposal," the leaked State Department document said.

That proposal, as described in a 2010 document from the Japan Atomic Energy Agency obtained by ABC News, is a highly technical how-to on nuclear facility safety -- from the safe operation of nuclear facilities in crisis, to the protection of the actual nuclear materials and guards against proliferation.

CLICK HERE to read a PDF version of "Nuclear Data in Safety and Security" from the JAEA.

Even with the 3 S's system, Japan appeared overwhelmed by the quake, according to Tony Pietrangelo, a spokesman for lobbying group Nuclear Energy Institute.

"Clearly what happened in Japan is well beyond what [the nuclear plants] were designed for," he said.

CLICK HERE to read about nuclear emergency disaster concerns in the U.S.

Representatives at the IAEA did not respond to requests for comment on this report.

ABC News' David Kerley and Cindy E. Rodriguez contributed to this report.

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