Wednesday, April 27, 2011 What would it take for a nuclear meltdown to happen here? By Julien Gorbach
The nuclear disaster that continues to unfold at Japan’s Fukushima Daiichi nuclear plant raises questions about safety in south Louisiana, a hurricane-prone region powered by three nuclear reactors in the state and neighboring Mississippi.
Even skeptics would be hard-pressed to point out glaring vulnerabilities in the multiple layers of safeguards at Entergy’s River Bend plant in St. Francisville, Waterford 3 in Killona and Grand Gulf plant in Port Gibson, Miss. But as the Japanese are finding, safeguards that work on paper don’t necessarily work during a real meltdown, and the Fukushima crisis highlights what seems to be the major concern for the Entergy plants: the danger of power failure.
Compared to all other factors that could lead to a meltdown, a “station blackout” at River Bend posed a greater proportion of risk — 88.2 percent — than at any other plant in the country, according to the Nuclear Regulatory Commission’s most recent report, published in 2005.
“It dwarfed everything else combined,” says David Lochbaum, director of the Nuclear Safety Project for the Union of Concerned Scientists. “All of the other things were only 13 percent of the risk (according to an earlier report the NRC released in 2003). Station blackout is a threat to all plants. River Bend just had the highest percentage of its risk being represented by that.”
Grand Gulf’s total blackout risk was 32.16 percent and Waterford’s was 52.14 percent, within the top 15 of the 104 reactors nationwide. The national average was 17.5 percent.
The same report points out that the actual chance of a partial meltdown at River Bend is eight in 1 million — almost unimaginably slim. And since 2005, Entergy has acquired a backup diesel generator for its battery at the River Bend plant, adding yet another layer of protection. An Entergy spokesperson says the chance of a meltdown now stands at one event per every 1 million years. Nevertheless, representatives at the NRC and Entergy could not say why the comparative threat of a blackout at River Bend ranked so high in the first place.
In 2003, when the NRC originally reported on relative blackout risks, the commission based its 87.5 percent figure for River Bend on an assessment the plant conducted in 1993, says Katie Damratoski, a communication specialist with Entergy. She couldn’t say why the NRC’s figure jumped up half a percentage point in its 2005 update, but Damratoski notes that River Bend’s own assessment that year dropped the figure dramatically: down to 37.64 percent.
Without power, a plant cannot cool its fuel rods, which contain nuclear material that generates heat even when a plant isn’t running. They must be cooled constantly so they don’t overheat, break open and release radioactive material resulting in the situation called meltdown. At Fukushima, the tsunami wiped out backup diesel generators at three of the six reactors. Batteries, the final layer of protection against a power outage, lasted for eight hours, which was not long enough for emergency crews to bring in another power source.
While the Japanese batteries had eight hours of power storage, the batteries at 93 of the United States’ 104 plants, including River Bend, have only four hours’ worth.
River Bend has three levels of backup power, says Jerry Roberts, director of nuclear safety assurance at the plant. If the facility no longer can draw electricity through either of its two connections to the regional grid, it has three diesel generators to power cooling pumps. A second level of backup is a battery, which lacks enough juice to pump cooling systems, but can keep gauges and controls alive so the plant’s own steam can be used for power. The final fallback is a diesel generator that can recharge the battery.
The structures at River Bend are built to withstand gales of 100 mph and tornadic winds of 290 mph. The plant sits on a hill 95 feet above sea level and 40 feet above the estimated maximum level of flooding from severe weather events.
In the past, safety watchdog groups have raised concerns about the generators.
Mary Olson, director of the southeast office of Nuclear Information & Resource Service, points to Hurricane Andrew, when the south Florida plant at Turkey Point lost off-site power for more than five days. Because Florida Power & Light Company did not bring in a shift change by helicopter, the same crew worked around the clock to keep the generators going, she says.
“They did manage to [keep the generators running],” Olson says, “but I talked to one guy who was there, who said that they held it together basically with paper clips and rubber bands at one point, because diesel generators are really not designed to run continuously.” Officials at FPL did not respond to calls for comment by press time.
Like the combustion engines in cars and trucks, diesel generators don’t always start if they haven’t been turned on for weeks, and they weren’t originally designed to run continuously.
The nuclear industry has been aware of this since the 1970s, and the NRC has required plant operators to upgrade their entire technology, says Scott Burnell, a public affairs officer with the NRC.
“As time has gone on, emergency diesel performance of generators at nuclear plants has improved considerably,” he says. “And any time in the course of normal testing they have an issue with them, they pay attention to it immediately, for obvious reasons.”
Burnell adds that Olson’s example of Turkey Point, which withstood the Category 5 force of Hurricane Andrew, demonstrates that plants are capable of running for extended periods after natural disasters. So far, Roberts says, the backup systems have worked at Waterford and River Bend. Waterford depended on its generators for five days following Hurricane Katrina in 2005, and River Bend shut down in 2008 during Hurricane Gustav, which tore the sheet metal off three sides of the plant’s turbine building.
The NRC’s 2005 study indicated failure rates for the startup and continuous operation of generators were very low — less than half a dozen per 1,000 tests.
Lochbaum also has raised concerns about relying on backup systems. In a Senate hearing March 29 on lessons learned from Japan, Lochbaum suggested an off-site supply of generators and additional batteries should be stored near every plant so more resources would be available in case backup systems ran out before power could be restored.
“Japan shows what happens when you play beat-the-clock and lose,” he says.
Burnell, however, argued that these safeguards were put in place after the Sept. 11, 2001 terrorist attacks. The agency has led emergency management exercises to ensure responders are prepared to quickly bring in additional, off-site resources.
NRC oversight has also been criticized. A Union of Concerned Scientists report released last month concluded that nuclear regulation is effective, but not consistent. In an interview with National Public Radio’s “Talk of the Nation Science Friday,” Lochbaum said that in 1998, Congress caved to complaints by nuclear plant owners and instructed the NRC to back off, threatening the agency with a 40 percent cut in its budget.
“So the NRC, threatened with a huge budget cut like that, folded their tent and went away,” Lochbaum said. “It’s kind of like MMS [Minerals Management Service] all over again.”
The MMS, which used to regulate oil and gas drilling, became embroiled in scandal in 2007 and 2008, when internal federal investigations revealed that MMS officials had accepted gifts, shared marijuana and cocaine and had sexual relations with the same industry executives they were charged with overseeing.
Burnell says funding for the NRC has ebbed and flowed over the years. It increased during President George W. Bush’s second term, reflecting that administration’s interest in nuclear power. According to the NRC’s website, however, the agency faces an 18 percent cut in net appropriations for 2012, wiping out a $25.6 million increase it received in 2010. The cuts include $8 million from the Nuclear Reactor Safety Program, which is responsible for continuous oversight, licensing and other duties that ensure reactors operate safely; and $20.7 million from the Nuclear Materials and Waste Safety Program, tasked with the transportation and extended storage of radioactive waste. It is not immediately clear what impact Congress’ cuts will have on the affected programs.
The NRC is dependent on the nuclear industry for 90 percent of its funding. Olson argues that while Congress has an oversight role in approving the budget, “Ultimately the industry pays its regulator, and you tend to work for the people who pay you, and there has not been strong evidence of independence on the Nuclear Regulatory Commission, particularly in the last 20 years.”
This should be a big concern in Louisiana because there is no independent watchdog group with expertise in nuclear plant safety keeping a close eye on River Bend, Waterford and Grand Gulf. Even before Katrina, Olson says, such people were retiring and moving on, and even more are gone now.
“It’s sort of a — I hate to say it — a bit of a blackout, in terms of the regional connection,” she says.