OTSU, Japan Japan's western Shiga prefecture, one of the nation's biggest sources of drinking water, threatened on Friday to oppose the restart of nearby nuclear reactors unless the government met several demands designed to prevent a repeat of the Fukushima disaster.
Shiga, whose Lake Biwa provides water for 14 million people, more than one in 10 Japanese, lies near a string of nuclear plants in adjacent Fukui prefecture - giving Shiga a distinctive voice in the debate over the future of atomic power.
"We cannot say yes to restarts until we are certain that they are absolutely safe," Shiga Governor Yukiko Kada said in an interview.
She also listed other demands such as setting up a new atomic regulator to supervise the industry before restarts could go ahead and clarifying what the power supply and demand situation actually will be.
Prime Minister Yoshihiko Noda's administration is keen to restart the two reactors at Kansai Electric's Ohi plant in Fukui to avoid power cuts. All but one of Japan's 54 reactors are offline after undergoing maintenance checks, and none has been restarted due to public safety worries after Fukushima.
Shiga prefecture - or even Fukui - cannot legally block restarts if the government chooses to go ahead, but lack of agreement would be a huge political headache for the government given widespread public concerns about safety.
On March 11, 2011, a massive earthquake and tsunami wrecked the Fukushima nuclear power complex northeast of Tokyo, causing meltdowns, sending radiation into the air and forcing tens of thousands of people to evacuate from a 30 km (18 miles) radius.
Trade minister Yukio Edano, responsible for energy policy, says he wants local governments' understanding for the restarts.
Edano, Prime Minister Noda and two other key ministers this week basically approved safety standards that drew on lessons learned from the Fukushima accident.
But not all of the safety check list must be met immediately if operators can show how they will fulfill them later.
"There are areas that could take several years, such as making a higher levee, building an earthquake-proof building or preparing filters for when venting takes place," Shiga Governor Kada said.
"I'd be hard-pressed to go along if those things are excluded, and they say they've met the standards just based on what they've managed to get done at the time."
"It appears to me that they are compromising technological safety in a half-baked way," she added.
Kada also said reactors should not be restarted until a new, more independent regulatory agency is set up.
Critics say cozy ties between regulators and utilities were one key cause for the failure to prepare for a disaster like Fukushima, the world's worst in 25 years.
A new regulatory agency was scheduled to start on April 1 but the legislation is stuck in a divided parliament.
(Reporting by Yoko Kubota and Kentaro Hamada; Editing by Linda Sieg and Mark Bendeich)