By Yoko Kubota
TOKYO, Jun (Reuters) - Japan on Tuesday pledged to overhaul regulation of nuclear power, saying that lax standards and poor oversight had contributed to the worst nuclear accident since Chernobyl in 1986.
Japanese officials from embattled Prime Minister Naoto Kan on down have been widely criticized for their handling of the nuclear disaster, triggered by a March 11 quake and tsunami, which has prompted a complete rethink on the future of nuclear energy in the quake-prone country.
The government report, which will be presented to the International Atomic Energy Agency, promised to set up an independent nuclear regulatory agency, breaking the long-criticized ties between the Japanese utility industry and officials overseeing its safety.
"What's most important for Japan to rebuild its trust is to transparently communicate to the international community about this accident," Kan told a meeting of cabinet ministers.
As an immediate step, Japan's Nuclear and Industrial Safety Agency announced new safety measures that utilities will have to show by this month how they will be enforced, officials said.
Currently, Japan is running only 19 of 54 reactors in operation before the disaster at the Fukushima Daiichi plant, raising the risk of deep power shortages into 2012.
Local officials government have been waiting for new safety standards to be introduced and implemented before approving a restart of the remaining reactors.
In a draft report earlier this month, the IAEA said Japanese officials had underestimated the threat from tsunamis to coastal nuclear plants.
The tsunami that crashed into the plant after the 9.0-magnitude earthquake has been estimated at around 14 meters (46 ft), nearly two-and-a-half times the height of the protective wall at Fukushima.
The quake and tsunami alone killed about 24,000 people.
Three reactors at the complex went into meltdown when power and cooling functions at the complex failed, forcing the evacuation of some 80,000 people and an effort to stabilize the plant expected to continue until at least January.
The IAEA report had urged Japan to reform its system of nuclear regulation so that the agency overseeing nuclear safety is independent of the ministry charged with promoting it.
Japan will present its official report to the Vienna-based U.N. watchdog at a meeting later this month, and another panel of Japanese experts is preparing its own analysis of the accident.
In 2007, the IAEA was ignored when it called on Japan to create a more powerful and independent nuclear regulator and clarify the responsibilities of the four government agencies involved in plant safety.
Japan has also been widely criticized for a halting and incomplete disclosure of key information about the plant and the plume of radiation that successive explosions produced.
In the most recent example, officials from Japan's Nuclear and Industrial Safety Agency said on Monday that the Fukushima accident had generated more than twice as much radiation they had previously estimated.
The new estimate of 770,000 terabecquerels of radiation is more than seven times the amount of radiation produced by Three Mile Island accident in the United States but still just 15 percent of the estimated discharge at Chernobyl.
The Japanese report said the confused lines of responsibility complicated the early response. Policies on how to manage nuclear accidents were established in 1992 but never reviewed or strengthened, it said.
(Writing by Kevin Krolicki; Editing by Nick Macfie)