Experts from the International Atomic Energy Agency have begun their first inspection of a Japanese nuclear power plant that has undergone official "stress tests" - a key step required to restart dozens of nuclear plants idled in the wake of the Fukushima crisis.
A 10-member IAEA team was inspecting the number three and number four reactors at the Ohi nuclear power plant in Fukui, western Japan, where 13 reactors are clustered in four complexes along the snowy Sea of Japan coast, making it the country's nuclear heartland.
"We look forward to seeing the types of specifications and types of improvements that Kansai Electric Power has made at the Ohi nuclear plant," mission leader James Lyons said at the outset of the plant visit. "Because that would give us opportunity to see how nuclear utilities are responding to these instructions."
After exchanging views at a meeting, members of the IAEA mission inspected an emergency power unit set up behind the number three reactor building. They watched three plant workers plug in several cables and start the generator as black smoke rose up to the grey sky in heavy snow.
The inspection comes a week after Japanese nuclear safety officials gave preliminary approval on the Ohi reactors, a step closer to restarting them.
Authorities have required all reactors to undergo stress tests in the wake of the Fukushima nuclear crisis and make necessary modifications to improve safety.
The stress tests, similar to those used in France and elsewhere in Europe, are designed to assess how well the plants can withstand earthquakes, tsunamis, storms, loss of power and other crises.
Only four of Japan's 54 reactors are currently operating, and if no idled plants get approval to go back on line, the country will be without an operating reactor by the end of April.
Another hurdle will be gaining local approval for the plants to restart. While local consent is not legally required for that to happen, authorities generally want to win local support and make efforts to do so.
Premier Yoshihiko Noda has said that the final decision on whether to restart the nuclear plants would be political, suggesting that the government would override possible local opposition if Japan's energy needs were dire.