Two Japanese nuclear operators have moved to extend the life of reactors at their coastal nuclear plants
Kansai Electric Power Co said it had filed a petition with Japan’s nuclear regulatory agency to keep the No. 2 reactor at its Mihama nuclear plant running beyond 2012, 40 years after it first went into operation.
Chubu Electric Power Co said it had completed plans for building a $1.3 billion wall to protect its Hamaoka plant from the kind of tsunami that triggered a safety crisis at the Fukushima Daiichi nuclear plant, in northeast Japan, in March.
Mihama is on the north coast and Hamakoka on the south coast, both southwest of Tokyo.
Japan’s Nuclear and Industrial Safety Agency will have to weigh the safety of both plants against a new set of tests at a time when public concern is high over both the risks of nuclear power and the economic costs of abandoning it.
Japanese utilities are currently operating 17 of the 54 reactors that had been available before the March 11 earthquake and all of those could be shut down by May for maintenance if public worries over safety continue to stall reactor restarts.
Shutting down all of Japan’s reactors would create a power shortage of up to six per cent during the power consumption peak in August 2012, and force manufacturers to stockpile inventory in the spring and then ramp up output again in the autumn, SMBC Nikko Securities has said.
Daiwa Institute of Research estimates that shutting down nuclear power would reduce economic output by 2.5 per cent - equivalent to 14 trillion yen - over the next decade.
“Higher electricity costs would increase costs for corporations and individuals and weigh on both capital spending and consumption,” said Daiwa senior researcher Mikio Mizobota.
Japan’s planned nuclear “stress tests”, which are loosely modelled on safety assessments by the European Union, will examine how well plants could hold up to the kind of massive earthquake and tsunami that cut off power to cooling systems at Fukushima and caused three of its reactors to melt down.
About 80,000 residents near the Fukushima plant have been forced to evacuate and may have to wait until year-end before a government plan on resettling the area is ready.
Earlier this week, Japan’s government suspended shipments of beef from Fukushima as concerns about radiation contamination has spread from vegetables and seafood to livestock and water.
Chubu, which provides power to a major auto production hub in central Japan, said it would aim to complete tsunami defences at Hamaoka in December 2012. The utility shut the Hamaoka plant in mid-May after Prime Minister Naoto Kan called for its closure, saying the area was at particularly high risk from a major earthquake.
Chubu said it plans to build an 18-metre high wall around the nuclear plant. The tsunami is thought to have reached as high as 15 metres at the Fukushima plant.
The utility said it would also take steps to prevent water from entering the nuclear facility.
Critics, including leading earthquake experts, have warned that the plant’s location at the tip of a sandy peninsula jutting out into the Pacific also puts it at particular risk.
Chubu decommissioned the plant’s No.1 and No.2 reactors in 2009 after concluding it would cost too much to make them meet tougher seismic standards. It says the three other reactors on the site are now designed to withstand a magnitude 8.5 quake.
Kansai’s Mihama nuclear plant in Fukui has faced scrutiny because of the age of its three reactors, which were completed between 1970 and 1976. In 2004, a pipe broke in the No. 3 reactor and sprayed hot water and steam that killed four workers and injured seven. In 2003 and 1991, the No. 2 reactor had breakdowns in its steam generators.
Nuclear critics called on government officials to block an extension for the No. 2 reactor when they review the application for another 10 years of operation.
“If there had not been the case of Fukushima, the government would probably have given permission without hesitation,” said Hideyuki Ban, co-director of the anti-nuclear Citizen’s Nuclear Information Center. “Now safety should be the top priority.”