By Shinichi Saoshiro
TOKYO (Reuters) - Japan should be less conservative in cleaning up vast areas contaminated by radiation from the world's worst nuclear disaster since Chernobyl, a team of visiting U.N. nuclear experts said on Friday.
Japan is burdened with the task of cleaning up the tsunami-hit Daiichi nuclear power plant in Fukushima, located 240 kilometres (150 miles) northeast of Tokyo, and the surrounding regions.
The plant, crippled by a devastating earthquake and tsunami in March, has spread radiation, stoking public concerns and forcing some 80,000 people to leave their homes after the government banned entry within a 20 km radius of Daiichi.
Removing layers of topsoil from areas contaminated by radiation is one of the methods being considered by Japan, but the team of 12 experts sent by the Vienna-based International Atomic Agency (IAEA) said it would be impractical.
"We are not saying the government's approach is over-conservative, what we want is for the government to avoid becoming over-conservative in the future," said Tero Tapio Varjoranta, the team's deputy leader.
Efforts to bring the plant under control have progressed steadily, but Japan still faces the challenge of decontaminating vast land affected by the disaster, which the environmental ministry says could be about 2,400 square km (930 square miles), an area roughly the size of Luxembourg.
Japan's environmental ministry has said the method of scraping off surface soil could result in about 29 million cubic metres of radioactive waste that needs to be disposed, and finding a final storage place for the debris is seen as a major headache for the government.
"Where applicable, there are methods that do not require storage. There are about 60 remediation technologies available. We are taking the advice from our experiences in Chernobyl, where a lot of mistakes were made," Varjoranta said.
Some of the methods included mixing up the removed topsoil with clean material for the construction of roads and reinforcement of banks, or storing them in various layers, the IAEA says.
The IAEA team, which will end its nine-day mission on Saturday, will present a final report to the Japanese government next month.
"The word 'conservative' appeared several times in the report. We have been working based on the concept of the public's safety and I don't think that is wrong," said Goshi Hosono, Japan's environmental minister, after being presented with a draft report by the IAEA officials.
But he added: "We need to take their advice into consideration when we create our road map for the storage of radioactive waste."
(Additional reporting by Yoko Kubota; Editing by Yoko Nishikawa)
