Japan's economy minister said Monday two nuclear reactors tentatively met government safety standards even though completing improvements will take several years, paving the way for final approval for their startup soon.
All but one of Japan's 54 reactors are offline for regular safety checks, and the last will be shut down in May. Residents fear another disaster like the Fukushima crisis, but Japan faces a severe power shortage if reactors are not restarted.
The government issued new safety guidelines last Friday to address residents' worries. In response, Kansai Electric Power Co. submitted its safety plans earlier Monday for two reactors at the Ohi plant in Fukui prefecture, saying the full upgrades will take up to three years.
Hours later, Economy and Industry Minister Yukio Edano said the No. 3 and 4 reactors at the Ohi plant "more or less met our safety standards."
Edano said top officials will go over the checklist one more time before making a final evaluation, then discuss a possible startup in light of electricity demands during the hot summer months. Kansai Electric said Monday that its service area, including Osaka and Kyoto, will face up to 20 percent of power shortage during the summer if the reactors stayed offline.
Edano said the Nuclear and Industrial Safety Agency said that the Ohi reactors' past safety upgrades since the Fukushima crisis alone could provide enough safety margins and protections to keep reactor cores from melting even in the event of a similar earthquake or tsunami.
The safety upgrade plans submitted by the utility also "demonstrated its voluntary effort to find necessary steps and take concrete action," Edano said.
Kansai Electric president Makoto Yagi, who handed the roadmap to Edano earlier Monday, said he will aim to achieve "the world's top-class safety" at the Ohi plant. "I hope a startup is approved as soon as possible."
However, more than one-third of the necessary upgrades on the list are still incomplete, utility officials said.
The startup guidelines are based on recommendations adopted last month by NISA. Some of the most crucial measures to secure cooling functions and prevent meltdowns as in Fukushima were installed, but the rest were not.
Filtered vents that could substantially reduce radiation leaks in case of an accident threatening an explosion, a radiation-free crisis management building and fences to block debris washed up by a tsunami won't be ready until 2015. This means the plant, as well as plant workers and residents, won't be fully protected from radiation leaks if a Fukushima-class accident occurs while the measures are being taken.
Some experts said a resumption without these key protections would leave the plant vulnerable.
Tadahiro Katsuta, a Meiji University associate professor who was on a government panel that produced nuclear safety recommendations, said the upgrades completed are "mostly quick-fix measures," and that more important ones, such as a crisis management center, have been put off.
"I doubt if this would suffice to carry out the lessons from Fukushima in the case of another accident," Katsuta told public broadcaster NHK.
Currently, the crisis management headquarters at the Ohi plant is in the basement, which would be flooded in case of a major tsunami, Kansai Electric officials said. The plant is relocating the function to a room next to the control room for the two reactors.
The Fukushima Dai-ichi completed a similar building at a slightly elevated area on the complex just a year before the disasters _ though it was meant for quakes. It was the key crisis management center after surviving the March 11, 2011, tsunami that washed into the plant, destroying the plant's power and cooling systems, causing three reactor cores to melt. Plant officials have said the building was key to their survival.
None of Japan's 54 nuclear reactors are equipped with filtered vents, although their operators are moving to install them in coming years.
Ohi town mayor Shinobu Tokioka called the roadmap a "step forward," but urged the central government and nuclear regulators to carefully review the reactors' safety.
Starting up the reactors would usually take one or two days after approval is granted, but it is still unclear how long it would take in this case. Edano is expected to visit the region to request a startup and gauge public reaction.
Local consent is not a legal requirement for restarting the reactors, though government ministers are unlikely to force if the mood is strongly against it.
Fukui, where 13 reactors are clustered in four complexes along the coast, is often called Japan's "Nuclear Alley."