Germany, Italy and Switzerland have decided to abandon nuclear power since Japan's Fukushima disaster [EPA]

The UN nuclear chief has called on countries to carry out risk assessments on their reactors within 18 months and for strengthened international safety checks to help prevent a repeat of Japan's atomic crisis.

Yukiya Amano, opening a ministerial meeting on improving safety after the Fukushima emergency, said UN experts should be able to carry out random reviews of nuclear power stations.

His proposals -- aimed at ensuring nuclear plants can withstand extreme events such as the earthquake and tsunami that crippled Fukushima -- may prove controversial for states which want to keep safety an issue strictly for national authorities.

"Public confidence in the safety of nuclear power has been badly shaken," Amano, director general of the International Atomic Energy (IAEA), said in a speech to ministers and regulators from the UN body's 151 member states.
 
Ten per cent of the world's 440 reactors could be checked during a three-year period, the veteran Japanese diplomat said, suggesting power operators could help foot the bill.

He said nuclear safety would remain a national responsibility -- making clear that governments would have the main task of testing, if only in theory, whether reactor systems could withstand various disaster scenarios.

Japan blamed

Meanwhile, in a report dealing with the country's ongoing nuclear crisis at the Fukushima, IAEA said Japan had understimated the harazd posed by tsunamis to nuclear plants.

The report, to be handed to the nuclear watchdog's member states, comes three months after a major earthquake triggered a powerful tsunami, killing thousands across Japan's vast coastline and severely crippling the atomic plant in Fukushima.

The plant with a damaged cooling system has been leaking radiation since then.

A preliminary version of the report presented in Tokyo earlier this month, however, praised Tokyo's response to the March 11 disaster as "exemplary".
 
Following the crisis at Fukushima, several countries, such as Germany, Italy and Switzerland, have decided to abandon nuclear power.