TOKYO Japan edged closer to its first nuclear power plant restart since the March earthquake following approval from a Japanese city mayor, but concerns about summer power shortages remained as it was unclear when other plants would follow suit.
Delays in reactor restarts, combined with the shutdown of tsunami-hit plants, have left Japan with only 19 of its 54 reactors still operating. Before the tsunami-triggered atomic crisis, nuclear power provided about 30 percent of Japan's electricity.
Reactors at Kyushu Electric Power Co's 36-year old plant in the town of Genkai in the southern Saga prefecture are likely to be the first to return online, pending an approval from the prefecture's governor Yasushi Furukawa. The Genkai city mayor has already given his consent to the restart.
"The Saga case will not pave the way for others to follow unconditionally," said Tomomichi Akuta, senior economist at Mitsubishi UFJ Research and Consulting Co in Tokyo.
"The government has to show a clear time schedule and benchmark for safety requirements for restarts," he said, adding that after Saga, the next target would be areas suffering from power shortage concerns.
Last week, Japan's trade and energy minister Banri Kaieda, undeterred by several dozen anti-nuclear protesters, tried to persuade local governments in the Saga prefecture that it was safe to restart nuclear reactors.
But Furukawa has said that he would need to take concerns of affected communities into consideration before an approval.
Kyushu would prepare for the restart immediately after approval from Saga's governor, the utility's spokeswoman said, adding that the 559 megawatts No. 2 Genkai reactor was likely to be the first to come online.
Electricity power companies remain on high alert to ensure power saving efforts are in place so as to at least secure a minimum reserve margin on electricity supply and avoid having to conduct rolling blackouts.
Kyushu on Tuesday began posting on its company website its forecast for daily maximum electricity demand to urge customers to curb excess electricity use.
"We are asking our customers to make their best effort to save as much electricity as possible, without causing health or other hazards," a Kyushu spokeswoman said.
Utilities generally see a reserve margin of 8-10 percent as a gauge for an adequate supply of electricity.
Chubu Electric Power Co, whose sole Hamaoka nuclear plant was shut after Prime Minister Naoto Kan asked for stricter safety measures, has asked users to save power, especially from Mondays to Wednesdays, when auto factories turn out cars ahead of rest days on Thursday and Friday.
Chubu's president, Akihisa Mizuno, however, has said there were no plans for rolling blackouts.
CENTER SEEKS SAGA APPROVAL
On July 8, central government officials will hold a second meeting with residents in Saga to convince them adequate safety measures are in place for the reactors to restart, an official at Saga prefecture government said.
The prefecture assembly will hold a special meeting on July 11 to discuss the restart issue, which appears to be favored by many in the assembly, though it is not clear if they are a decisive majority, the prefecture official said.
Saga governor Furukawa has also asked for assurances from Prime Minister Naoto Kan.
"The outcome of the assembly's meeting and talks with the prime minister are the conditions for Furukawa's decision," the prefecture official said, adding it was not clear how soon the governor could decide after clearing these conditions.
Kyushu Electric had the No.2 Genkai reactor ready for restart in March while No. 3 was ready in April, but it kept them shut pending approvals by local authorities after the March disaster fueled safety concerns.
Its Sendai No. 1 unit is also shut for planned maintenance while the Sendai No. 2 unit, currently in operation, will be shut for a planned maintenance by September 4. Kyushu Electric operates six reactors.
The utility forecast supply of 17,280 MW for the summer but if Genkai No. 2, No. 3 and Sendai No. 1 do not restart, it would be able to supply just 3.5 percent above estimated peak demand. Last summer's peak demand was 16,980 MW in the region it serves.
The March disaster triggered a radiation crisis at Tokyo Electric Power Co's Fukushima Daiichi plant, spurring shutdowns of reactors until safety measures were confirmed.
From July 1, Japan's government ordered large-lot power users in areas served by Tepco and Tohoku Electric to cut peak power consumption by 15 percent from last year, its first use of such a measure since the oil crisis of 1974.
(Additional reporting by Risa Maeda;Editing by Himani Sarkar)