A four-day international meeting of nuclear experts has called for a tightening of safety standards at nuclear plants across the world following the Fukushima nuclear accident in Japan in March.

Dire warnings of radiation spreading from Japan's embattled Fukushima Daiichi nuclear power plant to deadly effect across Japan, or even to California, are likely overblown, they say.

People who are evacuated from a nursing home which is located in evacuation area around the Fukushima Daini nuclear plant rest at a temporary shelter in Koriyama March 13 2011.