JOIN USPaying the price for extending reactor's life
The committee reviewing extensions pointed to stress cracks in the backup diesel-powered engines at reactor No 1 at the Daiichi plant, according to a summary of its deliberations that was posted on the website of Japan’s nuclear regulatory agency after each meeting. The cracks made the engines vulnerable to corrosion from seawater and rainwater. The engines are thought to have been knocked out by the tsunami, shutting down the reactor’s vital cooling system.
The Tokyo Electric Power Co, which runs the plant, has since struggled to keep the reactor and spent fuel pool from overheating and emitting radioactive materials.
Several weeks after the extension was granted, the company admitted that it had failed to inspect 33 pieces of equipment related to the cooling systems, including water pumps and diesel generators, at the power station’s six reactors, according to findings published on the agency’s website shortly before the earthquake.
Regulators said that “maintenance management was inadequate” and that the “quality of inspection was insufficient.” Less than two weeks later, the earthquake and tsunami set off the crisis at the power station.
The decision to extend the reactor’s life, and the inspection failures at all six reactors, highlight what critics describe as unhealthy ties between power plant operators and the
Japanese regulators that oversee them. Expert panels like the one that recommended the extension are drawn mostly from academia to backstop bureaucratic decision-making and rarely challenge the agencies that hire them.
Because public opposition to nuclear power makes it hard to build new power plants, nuclear operators are lobbying to extend their reactors’ use beyond the 40-year statutory limit, despite uneven safety records and a history of cover-ups. The government, eager to expand the use of nuclear energy and reduce the reliance on imported fossil fuels, has been largely sympathetic. Such extensions are also part of a global trend in which aging plants have been granted longer lives.
Over the next decade in Japan, 13 more reactors — and the other five at the Fukushima Daiichi plant — will also turn 40, raising the prospect of gargantuan replacement costs.
That is one reason critics contend that the Nuclear and Industrial Safety Agency’s committee in charge of inspecting aging nuclear power plants may play down its own findings.
In approving the extension in early February, regulators told Tokyo Electric to monitor potential damage from radiation to the reactor’s pressure vessel, which holds fuel rods; corrosion of the spray heads used to douse the suppression chamber; corrosion of key bolts at the reactor; and conduction problems in a gauge that measures the flow of water into the reactor, according to a report published in early February.
The committee, which convened six times to review findings gathered during inspections of the No 1 unit at the power station, found that Tokyo Electrichad met all required protections from earthquakes. Inspectors, however, had spent just three days inspecting the No 1 unit, a period that industry experts say was far too brief because assessing the earthquake risk to a nuclear plant is one of the most complex engineering problems in the world.
Despite these doubts, the committee recommended that Tokyo Electric be given permission to run the No 1 unit, which was built by General Electric and began operating in 1971, for an additional decade. During the approval process, the company claimed that the reactor was capable of running for 60 years.
Contamination
Mitsuhiko Tanaka, an engineer who worked on the design of the reactors at the Fukushima Daiichi plant, said the reactors there were outdated, particularly their small suppression chambers, which increased the risk that pressure would build up within the reactor, a fault eliminated in newer reactors. Since the tsunami, officials at Fukushima Daiichi have tried to relieve rising pressure inside the reactors, several times resorting to releasing radioactive steam into the atmosphere, a measure that in turn has contributed to the contamination of food and water in the area.
“It was about time the reactor was replaced,” Tanaka said. “The tsunami would have caused great damage, regardless. But the pipes, the machinery, the computers, the entire reactors — they are just old, and that did not help.”
Somewhat younger reactors, Nos 2, 3, and 4, also suffered extensive damage.
Regulators approved the 10-year extension even though aging reactors at Tokyo Electric, as well as those at other power companies, had suffered a series of problems as far back as a decade ago. Attempts to cover them up and manipulate data, particularly by Tokyo Electric, the country’s biggest utility, underscored not only the problems of the nuclear industry but also Japan’s weakness in regulating it. The company has admitted wrongdoing. A Tokyo Electric spokesman, Naoki Tsunoda, said: “We are committed to carrying out proper inspections in the future. We will study why this has happened and endeavor to inform the public.”
In 2000, a whistle-blower at a separate company that was contracted to inspect the reactors told regulators about cracks in the stainless steel shrouds that cover reactor cores at Fukushima’s Daiichi plant. But regulators simply told the company to look into the issue, allowing the reactors to keep operating.
Nuclear regulators effectively sat on the information about the cracks in the shrouds, said Eisaku Sato, the governor of Fukushima Prefecture at the time and an opponent of nuclear power. He said the prefecture itself and the communities hosting the nuclear plants did not learn about the cracks until regulators publicized them in 2002, more than two years after the whistle-blower reported the cracks.
In 2003, regulators forced Tokyo Electric to suspend operations at its 10 reactors at two plants in Fukushima and seven in Niigata Prefecture after revelations from whistle-blowers who gave information to Fukushima prefecture that the company had falsified inspection records and hid flaws over 16 years to save on repair costs. In the most serious incident, Tokyo Electric hid the large cracks in the shrouds.
“An organisation that is inherently untrustworthy is charged with ensuring the safety of Japan’s nuclear plants,” said Sato, governor from 1988 to 2006. “So the problem is not limited to Tokyo Electric, which has a long history of cover-ups, but it’s the whole system that is flawed. That’s frightening.”
Like many critics of Japan’s nuclear industry, Sato attributed weak oversight to a conflict of interest that he said essentially stripped the Nuclear and Industrial Safety Agency of its effectiveness. The agency, which is supposed to act as a watchdog, is under the ministry of economy, trade and industry, which has a general policy of encouraging the development of Japan’s nuclear industry.