By Risa Maeda and Aaron Sheldrick
KARIWA, Japan (Reuters) - Tokyo Electric Power Co sees no imminent resumption of operations at the world's biggest nuclear plant, shut down after last year's Fukushima disaster, further raising its costs as it spends more on fossil fuels to generate electricity.
A wall to protect the 8,212-megawatt Kashiwazaki-Kariwa station's seven reactors against tsunamis will not be finished until June next year, said Shiro Arai, deputy site manager.
"It is too premature to talk about when reactor restarts will happen," Arai told Reuters in an interview at the plant in Niigata prefecture on Japan's northwest coast.
An earthquake and tsunami on March 11 last year wrecked the company's Fukushima Daiichi plant, on the northeast coast, causing widespread radiation contamination.
All of Japan's nuclear plants were shut down after the accident, the world's worst since 1986, and public fear about nuclear safety has made it hard to persuade authorities to agree to approve the restart of plants.
Prospects also appear dim for any quick restarts as safety standards, to be drawn up by a new nuclear watchdog, will probably not be issued until the middle of next year.
Tokyo Electric Power Co, known as Tepco, needs to get Kashiwazaki-Kariwa running to reduce fuel costs, which totaled 1.34 trillion yen ($16.87 billion) in the six months through September when none of its reactors were online.
Restarting Kashiwazaki was also a central plank of the bailout of Tepco by the government, which injected 1 trillion yen of capital into the utility in July. Tepco also got a commitment from its banks to lend it another 1 trillion yen based on getting the reactors operating again to reduce losses.
Tepco President Naomi Hirose said two weeks ago that Tepco remained committed to starting the first of the plant's seven reactors in April. But Tepco's lack of transparency after the Fukushima disaster is a major concern, especially for those living in the shadow of the plant.
EARLIER QUAKE, SAFETY UPGRADES
Four years before Fukushima, the Kashiwazaki-Kariwa plant was damaged by an earthquake, triggering a fire and radiation leaks. At the time of the Fukushima disaster, three of its reactors were still being repaired and were not operational.
Arai, who had previously worked at Fukushima, showed Reuters elements of the 70 billion yen safety upgrade at the plant, about 220 km (130 miles) northwest of Tokyo.
Tepco is building tsunami walls to a height of 15 meters (50 feet) above sea level around the two clusters of reactors. The wall surrounding reactor No. 5, 6 and 7 has been completed but the defenses around the older 4 reactors are still being built.
Workers could be seen setting steel reinforcing in place for a 1-km (half mile) section of concrete wall. In the distance, waves crashed against a sea barrier.
On a hill above the reactor buildings, pump trucks and trucks with generators and heat exchangers are standing by in case the power and cooling system are knocked out.
The company was also filling a newly completed reservoir capable of holding 20,000 tonnes of water for use in an emergency to keep reactors cool.
Tepco still needs to have radiation filters installed to protect staff inside an emergency bunker it built after the 2007 earthquake, Arai said.
Work on fitting reactor building doors with seals to prevent water intrusion will not be completed until the end of September next year, according to a schedule provided by Tepco.
Geologist Masaaki Tateishi, a member of a panel of experts that advises the Niigata government on safety at the plant, said Tepco needs to reassess the danger from earthquakes.
"Tepco has mostly finished implementing the safety steps required after the Fukushima disaster apart from finishing the tsunami walls, but I doubt whether these upgrades are enough to avoid a repetition," Tateishi said.
($1 = 79.4200 yen)
(Editing by Robert Birsel and Miral Fahmy)