* Fukushima disaster came after tsunami knocked out back-up power

* Restoring full power to island may take a week - minister (Recasts throughout, adds comment)

TOKYO, Sept 6 (Reuters) - Power was restored to a nuclear energy plant in Hokkaido, northern Japan on Thursday after a strong earthquake left it relying on emergency generators for 10 nervous hours, but it may be a week before lights are back on all over the major island.

Triggering a blackout just after 3 a.m. local time, the magnitude 6.7 quake left at least seven people dead, more than 100 injured and dozens missing on Hokkaido, an island of about 5.3 million people whose capital is Sapporo. A major coal-fired power station was also damaged in the temblor that shut down the grid.

The situation at utility Hokkaido Electric Power’s three-reactor Tomari nuclear plant provided an uncomfortable, if comparatively brief, echo of the Fukushima Daiichi nuclear disaster in 2011. Reactors there melted down after a massive tsunami knocked out back-up generators, designed to maintain power to cool reactors in emergencies.

Though Tomari was shut down after the Fukushima disaster in 2011, it needs electricity to keep fuel rods cool, and had to rely on back-up diesel generators that kicked in after the quake until power was restored to all three reactors by 1 p.m. local time.

Hokkaido Electric is now scrambling to get power restored to households, factories and other customers, even as rescuers bring in heavy machinery and digging equipment to search for survivors that may be trapped in stricken buildings.

In another echo of the 2011 disaster, Hokkaido’s situation was compounded by difficulties in receiving supplies from neighbouring regions that remain dominated by separate utilities with their own grids.

A Hokkaido Electric spokesman said the utility was not receiving any supplies from the island of Honshu to the south - home to Tokyo, Osaka and Nagoya - despite there being a 600 megawatt connection for transferring power from the coast of Japan’s main island.

“Nationwide, they have been trying to bolster power systems by linking these fairly Balkanized domains, but it’s not as easy as it sounds,” said Andrew DeWit, professor of energy policy at Rikkyo University in Tokyo. “It requires equipment like transformers that is quite expensive and tailor-made.”

Damage to transmission lines, transformers and other equipment from the quake is likely also delaying the restoration of power, DeWit said.

By early afternoon, Hokkaido Electric had restarted one 125 megawatt coal-fired unit at its Sunagawa station.

Its Tomato-Atsuma coal station, which normally supplies about half the island’s electricity, remained shut after sustaining damage in the quake.

The abrupt halt in supplies from Tomato-Atsuma caused such a huge imbalance in supply and demand that other power plants on Hokkaido had to be shut own, industry minister Hiroshige Seko told reporters in Tokyo. it may take a week to restore power fully to Hokkaido, he said.

Thursday’s blackout prompted the shutdown of Hokkaido’s New Chitose Airport, a popular gateway to the most northern of Japan’s main islands, the second major airport to be knocked out in the country in two days after a typhoon swamped the nation’s third-biggest.

A number of industrial plants and factories were also affected.

A fire that broke out at a steel production facility at Mitsubishi Steel Manufacturing’s joint venture with Nippon Steel & Sumitomo Metal Corp in Muroran, Hokkaido, was extinguished with little damage to the facilities, a company official said.

The plant will work towards resuming special steel production after power supply from Hokkaido Electric is restored, the official said. It usually takes about eight hours to resume production after the power supply has been secured, he said.

Meanwhile Idemitsu Kosan, Japan’s second-biggest refiner by sales, stopped all refining and product shipments at its 150,000 barrels per day Hokkaido refinery, the only one on the island, an official told Reuters.

Kirin Beer, part of giant drinks maker Kirin Holdings Co , said it closed its Chitose plant, which accounts for about 5 percent of its beer output, because of the power outage. There was no structural damage to the factory, it said.

Sapporo Holdings Ltd said it closed down its Hokkaido brewery because of the lack of power.</s>* Fukushima disaster came after tsunami knocked out back-up power

* Restoring full power to island may take a week - minister (Recasts throughout, adds comment)

TOKYO, Sept 6 (Reuters) - Power was restored to a nuclear energy plant in Hokkaido, northern Japan on Thursday after a strong earthquake left it relying on emergency generators for 10 nervous hours, but it may be a week before lights are back on all over the major island.

Triggering a blackout just after 3 a.m. local time, the magnitude 6.7 quake left at least seven people dead, more than 100 injured and dozens missing on Hokkaido, an island of about 5.3 million people whose capital is Sapporo. A major coal-fired power station was also damaged in the temblor that shut down the grid.

The situation at utility Hokkaido Electric Power’s three-reactor Tomari nuclear plant provided an uncomfortable, if comparatively brief, echo of the Fukushima Daiichi nuclear disaster in 2011. Reactors there melted down after a massive tsunami knocked out back-up generators, designed to maintain power to cool reactors in emergencies.

Though Tomari was shut down after the Fukushima disaster in 2011, it needs electricity to keep fuel rods cool, and had to rely on back-up diesel generators that kicked in after the quake until power was restored to all three reactors by 1 p.m. local time.

Hokkaido Electric is now scrambling to get power restored to households, factories and other customers, even as rescuers bring in heavy machinery and digging equipment to search for survivors that may be trapped in stricken buildings.

In another echo of the 2011 disaster, Hokkaido’s situation was compounded by difficulties in receiving supplies from neighbouring regions that remain dominated by separate utilities with their own grids.

A Hokkaido Electric spokesman said the utility was not receiving any supplies from the island of Honshu to the south - home to Tokyo, Osaka and Nagoya - despite there being a 600 megawatt connection for transferring power from the coast of Japan’s main island.

“Nationwide, they have been trying to bolster power systems by linking these fairly Balkanized domains, but it’s not as easy as it sounds,” said Andrew DeWit, professor of energy policy at Rikkyo University in Tokyo. “It requires equipment like transformers that is quite expensive and tailor-made.”

Damage to transmission lines, transformers and other equipment from the quake is likely also delaying the restoration of power, DeWit said.

By early afternoon, Hokkaido Electric had restarted one 125 megawatt coal-fired unit at its Sunagawa station.

Its Tomato-Atsuma coal station, which normally supplies about half the island’s electricity, remained shut after sustaining damage in the quake.

The abrupt halt in supplies from Tomato-Atsuma caused such a huge imbalance in supply and demand that other power plants on Hokkaido had to be shut own, industry minister Hiroshige Seko told reporters in Tokyo. it may take a week to restore power fully to Hokkaido, he said.

Thursday’s blackout prompted the shutdown of Hokkaido’s New Chitose Airport, a popular gateway to the most northern of Japan’s main islands, the second major airport to be knocked out in the country in two days after a typhoon swamped the nation’s third-biggest.

A number of industrial plants and factories were also affected.

A fire that broke out at a steel production facility at Mitsubishi Steel Manufacturing’s joint venture with Nippon Steel & Sumitomo Metal Corp in Muroran, Hokkaido, was extinguished with little damage to the facilities, a company official said.

The plant will work towards resuming special steel production after power supply from Hokkaido Electric is restored, the official said. It usually takes about eight hours to resume production after the power supply has been secured, he said.

Meanwhile Idemitsu Kosan, Japan’s second-biggest refiner by sales, stopped all refining and product shipments at its 150,000 barrels per day Hokkaido refinery, the only one on the island, an official told Reuters.

Kirin Beer, part of giant drinks maker Kirin Holdings Co , said it closed its Chitose plant, which accounts for about 5 percent of its beer output, because of the power outage. There was no structural damage to the factory, it said.

Sapporo Holdings Ltd said it closed down its Hokkaido brewery because of the lack of power.</s>TOKYO (Reuters) - After an earthquake knocked out power to 5.3 million people this week, Hokkaido Electric expects to restore service to most of them by the end of Friday, but experts say the island-wide outage highlights fundamental flaws in Japan’s power grid.

Evacuees are seen at a gymnasium of elementary school, acting as an evacuation shelter, during blackout after an earthquake hit the area in Sapporo, Hokkaido. Kyodo/via REUTERS

Graphic: Earthquake in Hokkaido - tmsnrt.rs/2oJz6zd

The blackout that hit Japan’s northern island of Hokkaido after early Thursday’s quake was the nation’s worst in seven years, but it would have been less extensive if the utility was not so reliant on one large power station, had spread its plants more widely, and could transfer power more easily from other areas, specialists and energy executives said.

In the aftermath of Japan’s March 2011 disaster, when an earthquake and tsunami caused nuclear meltdowns and widespread power outages, the government mandated a boost in renewable energy supplies, opened up a roughly $70 billion retail electricity market to competition and created a grid oversight company to address these issues. But Hokkaido and other Japanese utilities have been slow to beef up networks and make them more resilient in a country that regularly experiences natural disasters, the specialists said.

“The crisis is primarily the result of over-reliance on a large coal plant in a centralized generation paradigm,” said Andrew DeWit, a professor of energy policy at Rikkyo University in Tokyo.

“That is odd and dangerous, considering the multiplicity of hazards Japan confronts and has experienced in recent years.”

While not as many people were affected by this week’s outage as after the March 2011 quake and tsunami, it was the first time a regional utility in Japan lost its full network, according to the country’s Federation of Electric Power Companies.

Hokkaido Electric Power had restored power to a little more than half of the island’s 2.95 million households by Friday afternoon after receiving supplies from nearby Honshu and rebooting some of its generating units.

The utility’s Tomato-Atsuma coal station, which normally supplies about half the island’s electricity, remained shut after sustaining damage in the quake. It may take a week to restore power fully to Hokkaido.

Hokkaido Electric aims to have power restored to about 80 percent of the island’s households by the end of Friday, according to Japan industry minister Hiroshige Seko.

The abrupt halt in supplies from Tomato-Atsuma, which has three coal-fired generators, caused such a huge imbalance in supply and demand that other power plants on Hokkaido were tripped and shut down.

“Adjusting supply and demand is very difficult. Hokkaido’s power grid is small and the share of Tomato-Atsuma is large, so it must have been much a more difficult a situation than after the big earthquake that struck eastern Japan,” said Tsutomu Oyama, professor of electrical engineering at Yokohama National University.

With its only nuclear plant shut pending approval to restart under new safety guidelines imposed since the Fukushima meltdowns of 2011, Hokkaido Electric has been investing in a new gas-fired station and expanding the capacity of its connection to Honshu. Cost cuts have slowed the process.

It plans to start operations of the gas-fired unit next month and complete a 50 percent expansion in capacity on the Hokkaido-Honshu connection by March next year, a Hokkaido Electric spokesman told Reuters. Those transmission lines currently can supply only about 600 megawatts of power.

Asked if there were lessons from 2011 that could have been applied to help mitigate the current situation, the spokesman said the utility had conducted drills for scenarios including the shutdown of all three units at Tomato-Atsuma but did not provide details.

“It is difficult to answer this question because the 2011 quake and yesterday’s quake are different situations,” he said.</s>Power has been restored to Manitoba Hydro customers in St. Vital.

The lights went out for more than 1,320 customers in the Southglen neighbourhood Thursday morning.

Hydro says the outage was caused by a squirrel that got too close to a power line.

Crews restored power by around 10 a.m. It went out just before 9 a.m.</s>TOKYO (AP) - The Latest on the powerful earthquake in northern Japan (all times local):

Japan’s nuclear regulator says external power has been restored at a nuclear power plant’s three reactors after a powerful quake on Hokkaido knocked out electricity across the northern island.

The three reactors at the Tomari plant had switched to emergency backup generators to keep spent fuel safely cooled. The Nuclear Regulation Authority says there’s no abnormality at the plant.

The restoration of power at the plant, however, won’t help restore electricity for the rest of Hokkaido as the reactors are offline for regular safety checks following the magnitude 6.7 quake.

The loss of external power briefly raised concerns because it brought back memories of the 2011 Fukushima nuclear meltdowns that were triggered by a massive earthquake and tsunami that destroyed power and key cooling systems.

The main railway company on the quake-hit northern Japanese island of Hokkaido says all trains have stopped due to power outage.

Hokkaido Railway Co. says high-speed bullet and all local trains on the island are halted. The company says it cannot update information on the social media due to the blackout.

The magnitude 6.7 earthquake struck southern Hokkaido early Thursday morning, knocking out power to nearly 3 million households. The outage also affected subways, power plants and hospitals.

Trade, Economy and Industry Minister Hiroshige Seko says damage at the main thermal power plant is delaying power restoration and that utility officials are rushing to get several other thermal and hydroelectric plants working to at least deliver some electricity within a day or two.

Japan’s economy minister says damage from a powerful earthquake at the main thermal plant has delayed the restoration of power on the main northernmost island of Hokkaido for more than a week.

Nearly 3 million households are without electricity across the island after a magnitude 6.7 earthquake struck southern Hokkaido early Thursday.

Economy, Trade and Industry Minister Hiroshige Seko initially instructed utility officials to restore power at the Tomato Atsuma thermal plant “within a few hours.” But Seko says the plan is now impossible due to damage.

Officials are trying to start up several other thermal and hydroelectric plants to get at least some power back on the island. Seko says the government is also arranging additional power supply from the mainland and sending power generating vehicles to hospitals.

This item corrects the spelling of the plant.

A Japanese government spokesman says two people have been confirmed dead after a powerful earthquake rocked the northern main island of Hokkaido.

Chief Cabinet Secretary Yoshihide Suga said the search was ongoing for those missing after the quake triggered dozens of landslides in the mountainous region near the epicenter. The magnitude 6.7 earthquake on Hokkaido early Thursday morning also knocked out power across the northern island.

Aerial footage showed slashes of brown earth on many heavily forested mountains, crushed homes and farm buildings and roads buried by avalanches of mud, logs and other debris.

The Japanese national broadcaster NHK is reporting that 125 people have been injured and about 20 are feared missing after a powerful quake triggered dozens of landslides in heavily forested mountains on the northern main island of Hokkaido.

The magnitude 6.7 earthquake struck southern Hokkaido early Thursday morning. Power was knocked out across the island.

The government said airports and many roads on the island were closed following the quake.

Officials said that 25,000 troops and other personnel were being dispatched to the area to help with rescue operations.

Japan’s minister for the economy, trade and industry Hiroshige Seko told reporters that efforts are underway to try to restore power in Hokkaido.

Nearly 3 million households over a widespread area are without electricity after a magnitude 6.7 earthquake struck southern Hokkaido at 3:08 a.m. Thursday (18:08 GMT Wednesday) at the depth of 40 kilometers (24 miles).

Seko said the government plans to use power from the area’s four hydroelectric plants as all the area’s fossil fuel power plants aren’t working.

Places like hospitals will get priority, he said, noting he hoped to get power back “within a few hours.”

Power is still out at the area’s Tomari nuclear plant, but backup diesel generators have kicked in so the reactors’ fuel is continuing to be kept cool, according to the government nuclear authorities. The plant has also shut down.

A powerful earthquake hit wide areas on Japan’s northernmost main island of Hokkaido early Thursday, triggering landslides as well as causing the loss of power at nearly all of 3 million households and a nuclear power plant to go on a backup generator.

A magnitude 6.7 earthquake struck southern Hokkaido at 3:08 a.m. Thursday (1808 GMT Wednesday) at the depth of 40 kilometers (24 miles), Japan’s Meteorological Agency said.

The quake’s epicenter was east of the city of Tomakomai. It also struck Hokkaido’s prefectural capital of Sapporo, with a population of 1.9 million.

This story has been corrected to say the name of the thermal plant is Tomato Atsuma not Tomato Azuma.</s>Electricity was restored at 7:10 a.m., according to El Paso Electric.

Crews are still investigating the cause of the outage.

The area that was affected was south of I-10 between Cotton Street and US 54, according to the utility's outage map.

It was first reported at 6:18 a.m.</s>ROCKINGHAM — A power outage has affected about 5,200 Duke Energy customers in the East Rockingham area, a spokesperson for the company said Friday.

The outage began at about 7:30 a.m. and a text notification sent out a short time later to affected customers said the outage was “caused by power lines.” The text also stated that 1,224 customers had been affected as of 9:07 a.m., though Paige Sheehan, a spokesperson for Duke Energy, said the number of affected customers is around 5,200.

“Crews are on site investigating the cause and making necessary repairs,” Sheehan said. The estimated time of repair was 10:15 a.m. Friday, though it is unclear how many are still without power.

Sheehan added that the issue was likely a problem at the company’s substation. The outage map on the company’s website showed the outage being centered around a point near the intersection of McDonald Avenue and Fieldcrest Lane as of 10:30 a.m.

This story will be updated as more information becomes available.
Energy specialists and executives say a power outage from the earthquake could have been lessened if Hokkaido Electric did not rely so exclusively on the Tomato-Atsuma coal plant. The company has restored electricity to just over half of its affected customers.